1

Safety in Mines Research Advisory Committee

Final Project Report

DEVELOP TELE-CONTROLS FOR SELF-THRUSTING PERCUSSION DRILLING MACHINE

AND ASSOCIATED INTERFACE

RW OttermannAJ von WiellighNDL BurgerDr. VA Kononov

Research Agencies RE@UP, University of PretoriaCSIR Miningtek

Project number GAP 702Date of report October 2001

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EXECUTIVE SUMMARY

The purpose of this project was to develop tele-controls to control drillingoperations from a distance. The controls were fitted to the prototype quietrock drill and demonstrated to be working.

Noise is a generic hazard common to all commodities and, to a greater orlesser extent, all operations within mining. More people are exposed to therisk of noise- induced hearing impairment than to any other hazard. Thepneumatic percussion drill is a major contributor to noise-induced hearingimpairment in mines. The design and development of tele-controls for drillsso that the operator can be positioned away from the drill will reduce this risk.The tele-control of rock drills has the added advantage of increased safety tothe drill operator by his positioning away from the rock face. During thisproject such a system was developed, tested and demonstrated.

After a literature survey was conducted a functional analysis was done fromwhich a specification was drawn up. Different concepts were generated andevaluated. The preferred concept was presented to the SIMRAC technicalcommittee for approval after which a detail design was done. Anexperimental development model (XDM) was built and commissioned. TheXDM was successfully tested on surface and demonstrated.

The design of the quiet self-thrusting rock drill, developed during project GAP642, was used and the tele-controls incorporated into it. The tele-controlsystem consists of a hand held controller and the electronic unit in the drillunit, with which different valves are controlled. Radio control is used ascommunication between the hand held controller and the drill unit. Agenerator, powered by an air motor, is incorporated in the drill unit to charge abattery, which supplies electricity to the electronics.

As this was an experimental development model (XDM) no durability testswere performed and the electronics were also not built to withstandunderground conditions. In order for this technology to be used undergroundthe electronics have to be designed and packaged to withstand undergroundconditions. As a tendency exists for the introduction of drill rigs in mines it isalso recommended that tele-controls be incorporated in drill rigs.

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ACKNOWLEDGEMENTS

The authors would like to express their gratitude to the Safety in MinesResearch Advisory Committee (SIMRAC) for financial support of project GAP702 and also for the interest and technical input of the SIMRAC TechnicalCommittee.

To Dr. Valery Kononov and his team at CSIR Miningtek our sincereappreciation for their technical input and co-operation in making the project asuccess.

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TABLE OF CONTENTS

1 INTRODUCTION.................................................................................................6

2 METHODOLOGY................................................................................................7

3 LITERATURE SURVEY.....................................................................................8

3.1 DEFINITION OF TELE-CONTROLS.........................................................................8

4 FUNCTIONAL ANALYSIS AND SPECIFICATION ....................................10

4.1 FUNCTIONAL ANALYSIS ...................................................................................104.2 SPECIFICATION.................................................................................................11

5 CONCEPT DESIGN ...........................................................................................12

5.1 COMMUNICATION CHANNEL SELECTION ..........................................................125.2 CONCEPT LAYOUT............................................................................................13

5.2.1 Control functions .....................................................................................135.2.2 Portable controller...................................................................................145.2.3 Machine tele-controls...............................................................................14

6 DETAIL DESIGN ...............................................................................................15

6.1 DRILL...............................................................................................................156.2 CONTROLS .......................................................................................................15

6.2.1 Valve arrangement .......................................................................................156.2.2 Electronics in the drill.............................................................................156.2.3 Electronics in the controller.....................................................................17

7 OPERATIONAL PROCEDURE.......................................................................19

8 EXPERIMENTAL DEVELOPMENT MODEL (XDM) ................................22

9 TEST AND EVALUATION (SURFACE).........................................................24

10 CONCLUSION AND RECOMMENDATIONS...........................................27

11 REFERENCES.................................................................................................28

APPENDIX A: LITERATURE SURVEY...............................................................29

APPENDIX B: FUNCTIONAL ANALYSIS .........................................................37

APPENDIX C : OPERATIONAL INSTRUCTIONS, ELECTRONIC CIRCUITDIAGRAMS AND PROGRAM FLOW CHARTS .................................................47

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TABLE OF FIGURES

Figure 4-1 : System level functional analysis..................................................... 10Figure 6-1 : Valve configuration........................................................................... 15Figure 6-2 : Schematic overview of electronic control layout in the drill........ 16Figure 6-3 : Controller microprocessor and its peripherals.............................. 18Figure 7-1 : Functional representation of the remote controller...................... 19Figure 8-1 : Assembled XDM quiet rock drill with tele-control........................ 22Figure 8-2 : Controller of quiet rock drill with tele-control (XDM).................... 23Figure 9-1 : Photo of the quiet rock drill drilling into a granite ......................... 24Figure 9-2 : Sound levels (dBA) around the prototype quiet rock drill tested

on surface. ......................................................................................... 25Figure 9-3 : Sound levels (dBA) around a standard muffled Seco S215 rock

drill tested on surface ....................................................................... 26

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1 INTRODUCTION

Noise is a generic hazard common to all commodities and, to a greateror lesser extent, all operations within mining. More people are exposedto the risk of noise- induced hearing impairment than to any otherhazard. The pneumatic percussion rock drill is a major contributor tonoise-induced hearing impairment in mines. The design anddevelopment of tele-controls for rock drills so that the operator can bepositioned away from the drill will reduce the risk.

In addition to the cost of compensation and reduced productivityresulting from lost shifts, hearing conservation programmes (whichhave proven largely ineffective for a number of reasons) are expensiveto implement and maintain. The impact of hearing loss/interference onproductivity and safety also results in reductions in profitability. Thisindicates that engineering measures to control the noise hazard, whichare generally accepted as the preferred approach to hearingconservation, offer better prospects for success than receptor control orpersonal protection strategies.

During project GAP 642, the Design and development of a quiet, self-thrusting blast hole drilling system, a percussion rock drill wasdeveloped with a reduced noise level. In order to reduce the noiseexposure further, the operator has to stand away from the drill. Thishas the added advantage of increased safety to the drill operator bystanding away from the rock face. During this project the quiet rockdrill was further developed to include tele-control.

This is the final report on project GAP 702. During this project tele-controls for a self-thrusting percussion drilling machine and theassociated interface was developed and demonstrated.

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2 METHODOLOGY

The following methodology was followed during this project:• A literature survey was done to determine the best technology on

tele-control systems.• After gathering information from industry, a functional analysis was

done.• From the functional analysis the requirements for the systems were

concluded and the specification and design parameters drawn up.• Different concepts were generated and evaluated against the

specification and design parameters.• The selected concept was then presented to the SIMRAC Technical

Committee for approval.• The selected concept was designed in detail after which a design

audit was done.• An experimental development model (XDM) of the drill was

manufactured and commissioned.• The XDM was tested and evaluated on surface.

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3 LITERATURE SURVEY

A literature survey was conducted on use of standoff control and inparticular for portable drills. The worldwide review of drilling technologyshow that no stand-off control and monitoring system was developed oris currently used in production. The same result was obtained insurveys conducted by Carter (1993), Chadwick (1994,1999) andWoof(1997).

A summary of the literature survey is attached in appendix A.

3.1 Definition of tele-controls

The term "remote control" has been acceptable nomenclature for anynon-on-board method of control in the past. At present, tele-control isrecommended as a far more appropriate and descriptive term for thediverse array of systems that have been developed over the last twodecades for non-on-board control. Therefore, the principal methods oftele-control for underground mining applications are defined as follows:

Standoff control:This refers to the use of a portable controller, whereby an operator cancontrol a mining machine only within line-of-sight, relying solely on hisown visual and auditory senses to monitor operational activitiesdirectly. Operator safety depends on his ability and common sense.The costs of installation and operation are low (Thomas, 1988). Onlyminor changes to the machine are required to introduce this method.

Remote control:This method of tele-control enables mining operations to take placewithout the permanent presence of miners in a mining area. Thisconcept involves control from beyond the range of visibility and, assuch, the operator can be placed any distance from the machine thatwill ensure his safety.

Lack of sensory information for the operator can be overcome by usingvideo, audio and other relevant systems. Information from sensors onthe machine in the working area is transmitted via communicationchannels to the remotely positioned operator. This information may beprocessed before being presented to the operator. The same orseparate communication channels can be used to transmit controlinstructions back to the machine, which can initiate on-board controlfunctions. Significant changes to the machine and additional equipmentas well as high levels of technology are required (Kwitowski, 1992).

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3.2. Types of communication for tele-control

Tele-control systems can incorporate various types of communicationbetween the control station and the controlled machine or equipment:

• Physical line or umbilical control (hydraulic hose, hard wires,electrical or fibre optic cable and machine trailing power cable).

• Wireless (radio, infrared and ultrasonic).• Combined (i.e. using physical line and wireless communication)

The main factors that have to be taken into consideration whenselecting a particular type of communication are:

• Method of tele-control.• Type of machine to be controlled.• Level of mobility of the machine.• Mining conditions and associated constraints on technology that

can be utilised.• Presence of other machines in the same area.• Electromagnetic compatibility of tele-control with other systems

used in the vicinity.

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4 FUNCTIONAL ANALYSIS AND SPECIFICATION

4.1 Functional analysis

A functional analysis based on the requirements for the tele-control of the self-thrusting percussion-drilling machine wasdone from which a design specification was compiled. In figure 4-1 the system level of the functional analysis is shown andthe complete functional analysis is listed in Appendix B.

SYSTEM LEVEL

Figure 4-1: System level functional analysis

QUIET ROCKDRILL

QUIET DRILLING SELF-PROPELLED STANDARD DRILL

Sound from drill shaft Sound from drill Forward Back

ThrustN=1750NV=370 mm/min

Rapid SpeedV=370 mm/min

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4.2 Specification

The functional analysis was used to compile the following systemspecification:

1. Control drilling operation from portable controller:• Activate forward motion• Apply thrust• Activate water/air• Activate reverse• Stop

2. Control two machines simultaneously.3. Range of portable controller: 2-5m.4. Drills must be capable of operating simultaneously and

independently.5. Stop in the case of a communication channel interruption between

the portable controller and the drill.6. Sense position of drill (drilling depth indicator).7. Drilling cycle complete indicator.8. Drill jammed indicator.9. Selection of and calibration for different drill rod lengths.10. End position switch in the front of the drilling unit to prevent over-

travel.

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5 CONCEPT DESIGN

The design of the quiet, self-thrusting rock drill, project Gap 642, wasused as the basis for the concept of this project. The different conceptswere based on different types of communication and thus thecommunication channel selection. In appendix A the different types ofcommunication as well as their advantages and disadvantages arediscussed.

5.1 Communication channel selection

As the concept for the drill itself was finalised during project GAP 642the selection of the communication channel was the most importantaspect on the implementation of tele-control.

The advantages and disadvantages of the communication channelsdiscussed are presented in appendix A. During the selection of thecommunication channel three main factors were considered:• At least two machines to be controlled simultaneously by the same

controller;• Harsh environmental condition and limited working space;• Relatively small space available in the drill.

The use of an umbilical cord is too delicate and restrictive for theoperator, particularly in such a restricted area as in a stope. Theprotection of the umbilical cord in underground conditions will be verydifficult. Therefore, the umbilical control concept was not considered.

Wireless control provides better operational freedom and does notrestrict mining operations. There are two alternatives available forimplementation:• Infrared control• Radio control

The infrared channel can be utilized when used to control a singlemachine with a suitable place for the installation of a photo receiver. Tofulfill the requirement to control two drills, an infrared transmitter willhave to provide an exceptionally wide transmission angle in order to“illuminate” both drills. The width of the transmission angle required tocover two machines will have to be close to 180°, which is not practical.The re-orientation of the infrared controller implies that the drill willhave to continue operating without a control signal, a situation that isnot desirable from a safety point of view. With infrared control anoptical window for the receiving photodiode has to be installed on thedrill. The position of this window, durability and its cleaning are limitingfactors for the use of infrared.

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Radio control has the following advantages:• Two or more machines can be controlled simultaneously.• Line of site is not necessary.• The receiver can be placed in a safe position away from the

harsh environmental conditions.• It can be fitted in limited space.

As umbilical cord and infrared control are not practical and because ofthe inherent advantages of radio control, radio control was chosen asthe preferred concept.

5.2 Concept layout.

5.2.1 Control functions

1. The machine can be started and controlled by a portablecontroller within a range of 2-5 m.

2. Two machines be controlled simultaneously.3. The machine should stop in the case of a communication

channel interruption between the portable controller and themachine.

4. While one machine is being controlled, the other machine shouldcontinue implementing an earlier instruction. That is, allmachines should be capable of operating simultaneously andindependently.

5. Each machine be equipped with a revolution counter on thethrust screw, indicating the drilled depth.

6. For safety and calibration purposes, an end position switch beinstalled in the front part of the drilling machine to prevent over-travel. This switch also serves as the zero position and indicatorto reverse the drill.

7. The drilling depth be transmitted to the portable controller. Thedepth is indicated on the portable controller by means of a bardisplay. A green light on the portable controller indicates thecompletion of the drilling cycle.

8. A red light on the portable controller indicates that the drill isjammed. If, during the drilling process, no movement is detectedwithin two seconds, the red light comes on.

9. The operator is able to select between different preset drillingrod lengths. These must be selected to determine how far themachine must retract to get to the starting position.

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5.2.2 Portable controller

The portable controller complies with the following specifications:

Operational frequency, MHzTransmitter 430Receiver 418

Radiated power, mW 1,0Instructions 2x6Power supply, V 3 (2xAA)Machine position indicators 2 barsCycle completion indicators 2 greenMachine jam indicators 2 red

5.2.3 Machine tele-controls

The drilling machine tele-control and interface unit complies with thefollowing requirements:

Operating frequency, MHzTransmitter 418Receiver, 430

Data packet size, bits 32Power supply, V 12Standby battery, V; A/h 12; 4Valves to be controlled 3Normally closed limit switches 2Inductive revolution counter (3 impulses per revolution) 1Standby mode ON/OFF, msec 400/800

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6 DETAIL DESIGN

6.1 Drill

The design of the quiet, self-thrusting rock drill, developed duringproject GAP 642, was used as the basis for this project. A full set ofdetail drawings was made and included in the GAP 642 report.

6.2 Controls

6.2.1 Valve arrangement

The valve configuration in the drill is presented in figure 6-1. Threevalves are used for the following functions:

1.Generator On/Off2.Drill On/Off3.Thrust Forward/Reverse

.

Pressure Switch Generator

Generator On/Off

Drill On/Off

+_ 12V

Drill

Motor

Pneumatic inlet

(to electronics)

Forward/ReverseThrustMotor

Figure 6-1: Valve configuration

6.2.2 Electronics in the drill

In figure 6-2 an overview of the electronic control layout in the drill isshown. The detail electronic layout is attached in appendix C.

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R X

T X

Decoder

A n t e n n a

Microprocessor

Proximi ty sensor

F r o n t swi tch

N C

12V Bat te ry

Regulator

Vcc

Pressure swi tch

B a c k switch

N C

Forward/Reverse

Dril l On/Off

DrillStop

ReverseCalibrate

Bat terycheck

ID, Progress , Jam f lagPower f lag, Stopped f lag

Power

Generator On/Of f

Power

Encoder

Figure 6-2: Schematic overview of electronic control layout in the drill.

Power is available to the electronics when the main pressure switch isclosed, i.e. when the pneumatic hose is connected to the drill.Electronic filters on the pressure and limit switches eliminate unwantedeffects such as switch bounce.

The microprocessor in the drill fulfils the following functions:

1. When the pneumatic hose is connected and the portablecontroller has not initiated a Power On command, the rigelectronics is in standby mode, a power saving feature. Instandby mode, the power to the electronics is cyclically switchedon for 400 ms and then off for 800 ms. The system remains instandby mode until the user holds the portable controller Powerswitch down for two seconds. When this occurs the system isput into operational mode. In operational mode the power to theelectronics is continuously on until the portable controller Powerswitch is held down for two seconds or the emergency stopswitch is pressed.

2. The battery level is monitored. If the battery voltage drops below10.5 volts, the generator is activated until the battery is charged.A 60 W air motor running at 6500 r.p.m powers a permanentmagnet electric motor, which is used as generator. The

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generator delivers 5 Amps at 13,5 Volts. A regulator fittedbetween the generator and the battery converts the generatoroutput voltage (which often goes above 20 V) and regulates it toa smooth 13.8 volts for charging. The Generator On/Off valveenables and disables the generator. When the generator isturned on, the voltage immediately rises to the 13.8V charginglevel. The battery voltage cannot be sampled while it is beingcharged. Charging for five minutes, turning off the charger,waiting for the voltage level to settle, and then measuring beforecharging again accommodates for this. This process is repeateduntil the battery voltage reaches a sufficient level at which pointthe Generator valve is turned Off.

3. By monitoring the direction and the proximity sensor pulses, thedrill position is tracked. When the machine is first put into use,an initial calibration is conducted to obtain the first reference.Each time the front limit switch is pressed, the reference positionis zeroed and any accumulated error eradicated.

4. Control of the automatic drilling process. This is initiated bypressing the Drill button, and involves the following sequence:Drill valve On, Forward valve On, front limit switch activated,Stop, Reverse valve On. Since the controller knows the selecteddrill steel length, the controller issues the final stop command atreaching the correct retracted distance, which sets both the Drillvalve and Reverse valve to Off.

5. Interpretation of the Stop and Reverse commands.6. Partial control of the calibration procedure for changing drill

steels: Upon receiving a Calibrate signal, the drill thrusts to thefront limit and stops. Upon receiving a further Calibrate signal,retracts the drill. The portable controller issues the rod sizeselection and the final Stop command.

7. The following data stream is put onto the transmitter: An identitycode, the drill position, jam indicator, power status indicator anda flag to indicate that the rig has stopped. This last flag acts asconfirmation after the portable controller sends a stop command.

6.2.3 Electronics in the controller

Each drill controlled from the hand held controller is controlled by aseparate identical microprocessor. The schematic layout of one of thetwo microprocessors with its peripherals is shown in figure 6-3. Thedetail electronic layout is attached in appendix C.

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Microp roces so r

R X

A n t e n n a

Progress Bar

Stop command

Lines to rods i z e L E D s

C y c l e C o m p l e t e L E D

Jam LED

Power On/Of f

Rod select bu t ton

Calibrate bu t ton

Calibrate command

EncoderReverse bu t ton

P o w e r bu t ton

Drill bu t ton

Stop bu t ton

A n t e n n a

T XD e c o d e r

Figure 6-3: Controller microprocessor and its peripherals

The microprocessor in the controller fulfils the following functions:1. Receive and interpret the data string sent by the drill unit (ID,

Progress, Jam_f, Power_f and Stopped_f). If no data is receivedwithin 4 seconds, flash the red LED of the progress bar andissue a Stop command.

2. If the Power button is held down for two seconds and the drillhas confirmed the power status (Power_f set) then toggle thepower on and off.

3. Store the set drill rod size and drill rod position in EPROM.4. Update the progress bar according to the current position.5. In both the Drill and the Calibrate sequences it sends a Stop

signal to the drill unit when the drill has retracted to the requiredposition.

6. Control the Cycle complete and Jam LED’s.

The schematic diagrams and the program description are given in theAppendix C.

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7 OPERATIONAL PROCEDURE

(Notation: Throughout this document, words in Italics depictcontrol panel buttons, valves, registers and indicator flags.)

The functions present on the remote controller are depicted in figure 7-1.

Figure 7-1: Functional representation of the remote controller

Normal Operation:

1. Ensure that the pneumatic and hydraulic hoses are connected tothe drill units to be used.

2. Turn on the controller (Controller On). The yellow LED on theprogress bar should illuminate indicating that the rig is inStandby mode.

3. Hold the Power button down for two seconds to set the rig toOperational mode. The yellow LED on the progress bar goes outand the previous system settings of rod size and progress arerestored. If no drill progress has been made, the Cycle completeLED is lit up and the bottom LED in the progress bar will flash.Release the Power button.

4. When Drill is pressed, the automatic drilling cycle commences: Ifthe drill rod was retracted to its proper starting position then the

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Cycle complete LED turns off at this stage. The system will turnon the drill, thrust to the maximum extent of the currentlyspecified drill rod, retract to the starting position and turn the drilloff. Upon completion of the drill cycle, the Cycle complete LEDlights up and the bottom LED of the progress bar flashes. Thisprocess can be interrupted at any time by pressing Stop,Reverse or Emergency Stop.

5. The drill unit goes back to Standby mode, by either holding thePower button down for two seconds, by turning off the controller(Controller Off) or by pressing Emergency Stop.

Drill steel length calibration:1. Press the Calibrate button. The drill will be advanced to the front

where it will stop. The drill steel can now be replaced.2. Pressing Rod Select will alternate LED’s between the various

drill steel sizes. Select the desired drill steel length.3. Once a drill steel has been selected, press Calibrate to retract

the drill to the correct position for the specified drill steel.

Notes and troubleshooting:1. The drill steel selection option is only available between the first

and second time that the Calibrate button is pressed. During thistime, both the Drill and Reverse buttons are deactivated. If theStop button is pressed during the calibration process, thecalibration process will be aborted and the previous set-up willbe restored.

2. The Emergency Stop button can be pressed at any time. Whenthis is done, the drill is stopped and will enter into Standbymode.

3. Other than during the calibration procedure, the Reverse buttoncan be used at will. The drill steel will automatically be stopped ifit reaches the starting point, that is, where the Cycle completeLED lights up. Pressing Reverse again can further retract thedrill steel. The rear limit switch will halt the drill if the user doesn’tpress Stop in time.

4. If communication is lost between the drill unit and the controllerthe red LED of the bar display will flash. Each time the lightflashes a Stop command is issued. If the user moves back intorange, normal operation will commence. The delay betweenmoving into range and the commencement of normal operationcan at times be lengthy and it is recommended to turn thecontroller off and then on again.

5. If no drill movement is detected within two seconds when the drillsteel is supposed to be moving forward or backward, the redJam LED will illuminate. This LED goes off when the movementcommences again. If the lack of movement turns out to be aproblem, the user should press the Stop button and clear theproblem.

6. If the pneumatic hose is connected for an extended period oftime without activation of the drill, the battery may run down. If

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the battery level drops below a specific level (10.5V) then thegenerator will automatically be activated for a time to rechargethe battery (see paragraph 6.2.2). The hand held controllercurrently has no battery level monitor installed.

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8 EXPERIMENTAL DEVELOPMENT MODEL(XDM)

The experimental development model (XDM) quiet rock drill was builtand commissioned. During the commissioning numerous changeswere made to the controls as well as to the hardware of the controls.After each change was implemented the unit was again tested. Infigure 8-1 a photo of the assembled drill is shown and in figure 8-2 aphoto of the hand held controller is shown.

Figure 8-1: Assembled XDM quiet rock drill with tele-control

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Figure 8-2: Controller of quiet rock drill with tele-control (XDM)

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9 TEST AND EVALUATION (SURFACE)

Surface tests of the XDM quiet rock drill with tele-controls drilling into anorite block were done. The tests were done in an open area to reducethe effect of reflections from hard surfaces adding to the soundpressure level. In figure 9-1 a photo of the drill drilling into a graniteblock is shown. A standard muffled S215 rock drill was also tested toget comparative results.

Figure 9-1: Photo of the quiet rock drill drilling into a granite block

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The noise levels were measured at predetermined points around thedrill and are shown in figure 9-2. A standard muffled Seco S215 rockdrill was also tested and the comparative results are shown in figure 9-3. The results of the tests show that the XDM quiet rock drill has amarked reduction in sound power levels measured.

From figure 9-2 it can be seen that the noise levels reduceconsiderably the further away from the drill unit. With the tele-controldrill the operator can be positioned away from the drill were the noiselevels are acceptable. With the operator positioned 2 m or further awayfrom the quiet rock drill the sound levels he will experience will be lessthan 88 dBA compared with the 97 dBA experienced by a operator of astandard muffled Seco S215 rock drill in the same conditions onsurface.

Figure 9-2: Sound levels (dBA) around the prototype quiet rock drilltested on surface.

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Figure 9-3: Sound levels (dBA) around a standard muffled Seco S215rock drill tested on surface

Penetration rates were also measured with both the quiet rock drill andthe standard muffled Seco S215 rock drill. A similar penetration rate ofapproximately 500 mm per minute was recorded with both drills.

As this was an experimental development model (XDM) the electronicswere not built to withstand underground conditions and no durabilitytests were performed.

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10 CONCLUSION AND RECOMMENDATIONS

The purpose of this project was to develop tele-controls to controldrilling operations from a distance. The controls were fitted to theprototype quiet rock drill and demonstrated to be working.

Tele-controls were successfully developed for the quiet, self-thrustingblast hole drilling system (GAP 642) and demonstrated. The specifieddesign criteria as set out in the system specifications were met. Aconsiderable reduction in sound levels was achieved with comparablepenetration rates to standard pneumatic drills. With the tele-control rockdrill the operator can be positioned away from the drill where the noiselevels are acceptable. This has the added advantage of increasedsafety to the drill operator by standing away from the rock face.

During this project the tele-control for drills has been successfullydemonstrated. In order for this technology to be used underground thefollowing is recommended:• Design and package electronics to withstand underground

conditions.• As a tendency exists for the introduction of drill rigs in mines it is

also recommended that tele-controls be incorporated in drill rigs.• Monitor and display the battery life left in the hand held controller.

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11 REFERENCES

Carter R.A..1993. New Technology makes mining remotely possible.E & MJ, September.

Chadwick, J., November 1994, El Teniente’s Sub-6 looks to automation,Mining Magazine, 266-270.

Chadwick, J., August 1999, Underground drilling and loading, MiningMagazine, 105-110.

Hamrin H. 1993. Automatic Drilling of Long Blastholes for Sublevel Stopingwith Simba 269 in the LKAB Kiruna Mine. CSM Quarterly Review, Vol.93,No.3.

Harper, G.S., Scanlon, T., November 1997, Develop a quiet non-atmosphere polluting blast hole drilling system, Safety in Mines ResearchAdvisory Committee, GEN 207.

Harper, G.S., Scanlon, T., January 1998, Evaluation and furtherdevelopment of a quiet non-atmosphere polluting blast hole drilling system,Safety in Mines Research Advisory Committee, GEN 311.

Kononov V.A. 1987. Infrared Communication Channel in underground miningconditions. Doctorate Thesis, Moscow Technical University (MVTU Bauman).

Kwitowski A.J, Mayercheck W.D and Brautigam A.L. 1992. Teleoperationfor Continuous Miners and Haulage Equipment. IEEE Transactions onindustry applications. Vol.28, No.5, September/October.

Martin D.P,Fitz M.M.1991. An Automated Drill and Blast System.Proceedingsof International Symposium on Mine Mechanization and Automation, Vol.1,June 10-13, Golden, Colorado.

Miess C, Kowal H.1992. Secure Radio Control of Mining Machinery. The 11-th WVU International Mining Electrotechnology Conference, Morgantown,West Virginia, 29 July.

Thomas R.T&.Miess C. 1988. Radio Control and longwall shearers - a costeffective combination. Australian Mining, January.

Van Niekerk, J.L., Heyns, P.S., Heyns M., Hassall, J.R., The measurementof vibration characteristics of mining equipment and impact percussivemachines and tools. Safety in Mines Research Advisory Committee, GEN503.

Woof, M., October 1997, Production Drilling: The sophisticates, World MiningEquipment, 14-18.

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APPENDIX A: LITERATURE SURVEY

30

A literature survey was conducted on stand-off control and in particular stand-off control for portable drills. The world-wide review of drilling technologyconducted by Carter (1993), Chadwick (1994,1999) and Woof (1997) showthat no stand-off control and monitoring system is currently used inproduction.

A.1 Definition of tele-controls

The term "remote control" has been an acceptable nomenclature forany non-on-board method of control in the past. At present, "tele-control" is recommended as a far more appropriate and descriptiveterm for the diverse array of systems that have been developed overthe last two decades for non-on-board control. Therefore, the principalmethods of tele-control for underground mining applications are definedas follows:

Stand-off control:This refers to the use of a portable controller, whereby an operator cancontrol a mining machine only within line-of-sight, relying solely on hisown visual and auditory senses to monitor operational activitiesdirectly. Operator safety depends on his ability and common sense.The costs of installation and operation are low (Thomas and Hiess,1988). Only minor changes to the machine are required to introducethis method.

Remote control:This method of tele-control enables mining operations to take placewithout the permanent presence of miners in a mining area. Thisconcept involves control from beyond the range of visibility and, assuch, the operator can be placed any distance from the machine thatwill ensure his safety.

Lack of sensory information for the operator can be overcome by usingvideo, audio and other relevant systems. Information from sensors onthe machine in the working area is transmitted via communicationchannels to the remotely positioned operator. This information may beprocessed before being presented to the operator. The same orseparate communication channels can be used to transmit controlinstructions back to the machine, which can initiate on-board controlfunctions. Significant changes to the machine and additional equipmentas well as high levels of technology is required (Kwitowsk et al., 1992).

31

A.2 Types of communication for tele-control

Tele-control systems can incorporate various types of communicationbetween the control station and the controlled machine or equipment.Appropriate examples are as follows:

- Physical line or umbilical control (hydraulic hose, hard wires,electrical or fiber optic cable, machine trailing power cable);

- Wireless (radio, infrared, ultrasonic);- Combined (using physical line and wireless channel).

The main factors, which have to be taken into consideration whenselecting a particular channel, are as follows:

- Method of tele-control;- Type of machine to be controlled;- Mining conditions and associated constraints upon technology

that can be utilized;- Presence of other locally or tele-controlled machines in the same

area;- Level of mobility of the machine;- Electromagnetic compatibility of tele-control with other systems

used in the vicinity.

A.3 Physical Line Systems

The first remote control system for a mining machine using a hydraulicdrive were via a pilot line from a portable controller incorporating manualpilot valves. Such umbilical control systems are still in commercialproduction. When an electro-hydraulic interface (set of solenoid valves),is installed on the machine, hard wires or cables can be used betweenthe machine and a controller, which uses buttons and toggle switches.The practical limit on the length of a control cord for a stand-off control is5-10 m.

Advantages

- Low cost and simplicity

Disadvantages

- Restriction of operator's movement- Safety limitations

A physical link between a portable controller and a mobile machine wasused in the first commercial application of stand-off control for miningmachinery. This method of stand-off control can comply with machinecontrol requirements but at the same time the umbilical control limits thefreedom of the operator and physical damage to the cable is a frequent

32

problem. A few cases have been registered where a control cable hasbeen caught by caterpillar tracks or armed conveyer pads and anoperator has been dragged under or into a machine when the portablecontroller was fastened to the operator's body (Kononov, 1987). Thismethod of stand-off control, is, therefore, not recommended forpermanent control of a mobile machine unless some special measureswere implemented.

A.4 Wireless Systems

A.4.1 Radio

The first attempt to use radio waves in mines took place in the 1920's.Today, radio stand-off control systems have several undergroundmining applications, notably for longwall, thin seam continuous minersand LHD machines. Without some casual "wave guide" such as cables,rails, steel ropes or pipes, a radio system cannot provide for longdistance out-of-sight control. In most cases a "leaky feeder", installedthroughout a mine, can provide reliable remote control links between acontrol suite and a mining machine.

Advantages

* It is easy to install, and only minor modification of machinery isrequired.

* Maintenance costs are moderate.* It provides reasonable ruggedness and does not restrict

day-to-day mining operations.

Disadvantages

* Propagation of radio waves is unstable.Propagation depends on:- Wavelength- Cross-section of mining development or face- Kind of rock, coal and moisture contents- Rock/coal stress- Conductive structures along propagation path.

* The electromagnetic field in a gate cross-section or near amachine chassis is unstable. Even a loose bolt on a machine inthe immediate vicinity of the receiver antenna may be a sourceof interference and a cause of dropouts (Thomas andHiess,1988).

* Cross activation is possible. Cross activation is defined as theresponse of a radio controlled machine to a radio signal notdirected to that machine (Carter,1993).

33

* A stand-off control system may cost as much as 10% to 15% ofthe total machine price (Thomas and Hiess , 1988). A reliablelong distance remote control needs a costly leaky feeder.

A.4.2 Infrared

In the mining industry, infrared radiation as an open communicationchannel has been used since the late 1970's. In France it was used forautomatic reversing of a mining plough, while in Germany infraredcommunication was employed for the tele-control of monorail haulagesystems. In the United Kingdom infrared communication was utilizedfor coalface alignment and powered roof support initiation. In the formerUSSR the first research in propagation of infrared radiation inunderground mines started in 1978 and commercial production ofinfrared stand-off control systems for LHD machines, loaders,roadheaders and shearers began in 1982 (Kononov, 1987).

Research and practical experience has shown that even withoutspecial optical devices, and despite the presence of coal dust up to alevel of 100 mg/m3, a total LED radiation power of 200 mW can givereliable transmission distances of 30-40 m without a problem. A singlelens at either the transmission or receiving side will increase thedistance to 60-80 m. Due to the reflection of infrared radiation fromroad and pillar surfaces, as well as scattering at coal/rock dustparticles, control is possible even without a direct propagation pathbetween the infrared transmitter and receiver.

In stone dusted roadways or non-coal mines, the surface reflects 40%of incident 0.95 ìm radiation and an out-of-sight transmission distanceof 10-15 m can be achieved. If a coal only surface is present whichreflects only 6-8% of radiation, a distance of 2-4 m could be expected.

Both, line-of-sight and non-line-of-sight transmission distances arelonger in non-coal mines.

The distance of non-line-of-sight control is dependent on parameterssuch as:- Transmitted optical power- Sensitivity of photo-receiver- Optical direction of transmitter and receiver- Mutual orientation of transmitter and receiver- Roadway cross section- Reflection coefficient of road/pillar surfaces.

34

Advantages

For standoff control an infrared channel has the following advantages:* Fully independent of mining or technological conditions. If

operator can see the machine it can be controlled at anycondition within transmission range.

* High level of electromagnetic interference immunity andcompatibility with other electronic and electrical equipmentexists.

* Low cost.* Harmless for human health.* Deliberate delimitation of the control area is possible.

Disadvantages

* The non-line-of-sight communication distance is short andscreening of direct infrared signals by moving equipment andpersonnel is possible. Using two or more spatially separatedtransmitters or receivers could prevent this problem.

* Periodical cleaning of transmission and receiving windows isneeded.

A.4.3 Safety of wireless systems

Special attention has to be paid to the design of radio and infraredcontrol systems to avoid cross activation. An underground mine inOntario, Canada, reported at least one fatality in 1989 due to a radiocross activation (Miess and Kowal, 1992).

Using different separate frequency channels in the same work area isessential to prevent interference. A new concept of a smart wirelesscontrol to prevent cross activation has recently been proposed: eachcomponent of a wireless control system is assigned its own ID code atthe factory - these ID numbers will be never used again. This allows theuser to interchange machine and operator units without compromisingthe security of the wireless channel. To exchange the codes anoperator connects a short cable between a portable controller and amachine unit. After about a second, the exchange or learning iscomplete and the system can be used in wireless mode. This operationmust be done when any part of a system is changed.

A.5 Tele-control for drilling and charging

35

The main purpose of introducing tele-control and computer control forlong-hole production drilling is to increase real drilling time, and toprovide accurate control of hole length and deviation. Running time fora drilling machine is normally only 60-70% of the time available fordrilling given travelling times, lunch breaks, ventilation requirements,etc. Computerisation of the drilling process enables rigs to work duringthese normally non-productive times, without operator's participation.

At Outokumpu Finnmine's Enonkoski Mine at least one hole is drilledby a Data Solo during the lunch break and one more while the shiftschange, increasing overall drilling metres per day by about one-third(Carter, 1993).

A rig can be left alone to drill the hole to the pre-programmed depthand after that to retract the drill string, dismantle it and put the rods in amagazine. Average increases of productivity can exceed 25%(Chadwick, 1994). In drill and blast technology, accurate hole positionsand orientations are the most critical factors affecting the tunneldimensions or fragmentation of ore. Laser beams can be used todetermine hole positions (drilling patterns) instead of manual marking-up of a face, and can reduce the amount of holes needed and the totaldrilling cycle time.

Computerised rigs are very complicated and expensive. The currentdifficulties with such drilling equipment are reliability and the lack ofskilled personnel to maintain and repair such equipment.

Tele-control and computer control also provides better and saferworking conditions for rig operators as they can be located away fromthe hazardous areas. In high grade uranium mines the application ofcomputerised drilling equipment can improve safety and productivitysignificantly.

The Kurina Mine in Sweden has produced millions of tons of iron ore bysublevel caving. Their equipment includes a fully automatic SIMBA 269(made by Atlas Copco) drill rig which can automatically extend, retractand store 54 drill tubes 1.875 m length. The operator is seated in aventilated and heated cabin, supervising the rig via closed circuit TV(Hamrin,1993).

In spite of tele-control and computerisation, an operator's role willcontinue to be vital in order to control the quality of an excavation. Heis also needed to adjust drilling parameters.

Tele-control for charging blast holes improves safety and operatorworking conditions. Infrared stand-off controlled pneumatic chargingmachines have been successfully used in Kombinat KALI in EastGermany (Kononov, 1987). The ROCMEC 2000, developed by NitroNobel AB, enables the operator to charge a hole and install the

36

detonator from the machine cabin thereby reducing the risk of injuryand eliminating manual labour.

A Miniature Blasting Method (MBM) was proposed in the late 1970's inthe USA to reduce drill and blast cycle times. The method eliminatesequipment "shuffling" in the face, drills small short holes, charges themwith a small amount of explosive and blasts one hole at a time. Itneeds no fuse to detonate the charge. These Drill-Charge-ShootModules (DCS) can be installed on suitable vehicles or LHD machinesand could be controlled in tele-control or automatic mode. Field testswere conducted at a quarry near Seattle. The basalt was drilled at arate of 10 cm per minute. Thirty shots were made with the DCS and theperformance of the explosive was reportedly excellent, using just 0.6kg/m3. The MBM has great potential for improvements throughextended application of tele-control and automation, particularly, forsmall drifts (Martin and Fitz, 1991).

37

APPENDIX B: FUNCTIONAL ANALYSIS

39

SYSTEM LEVEL

QUIET ROCKDRILL

QUIET DRILLING SELF-PROPELLED STANDARD DRILL

Sound from drill shaft Sound from drill Forward Back

ThrustN=1750NV=370 mm/min

Rapid SpeedV=370 mm/min

40

MISSION LEVEL

• Use of existing proven equipment• Acceptable life expectancy• Compatible• Maintainable• Reliable• Compact• Light• Robust• Simplicity• Visible• Sound power emission < 90 dBA• Safety• Self propelled• Quick/easy drill steel assembly• Flame proof• Materials with low spark temperature• Low vibration levels• Remote control

Scope of problem

Support mining activity0.0

Drill holes1.0

Drill functional2.0

41

SYSTEM LEVEL FUNCTIONAL DIAGRAM

Scope of problem

Position1.1

Forward propelled1.3

Activation of drill1.4

Backward propelled1.5

Drill holes1.0

Prevent drill falling over1.2

Drill is functional2.0

42

FIRST LEVEL: FUNCTIONAL DIAGRAM

No No

No

No

Place in position1.1.2

Anchor in ground1.1.4

Secure to rock face1.1.5

Prevent falling over1.2

Position1.1

Carry to stope1.1.1

Assemble air/water legs

1.1.3

Forwardpropelled

Activate rapidforward motion

1.3.1

Is drill steel in contactwith rock face?

Activate drill1.4

Apply thrust1.3.2

Is hole at correctdepth?

Backwardpropelled 1.5

Activate drill1.4

Activatewater/air1.4.1

Depth? Hole complete1.4.2

Backward propelled1.5

Activate rapidbackward motion

1.5.1

Is drill steel out ofhole?

Remove drill1.6

43

FUNCTION DESIGN PARAMETERS

1.1 POSITION

1.1.1 Carry to stope Light < 30 kg/ personCarry handleBright colour (bright yellow)No protruding extensionRobust (drop 3.5m onto 50mm steel ball –Denting not to affect function)MaintainableCorrosion resistanceNo lose itemsTwo man operation

1.1.2 Place in position Maximum length: 2000mmTwo man operationNo loose parts

1.1.3 Anchor in ground Two-man operationNo loose partsMaximum thrust: 1750NNo rotation of drill

1.1.4 Secure to rock face Two-man operationNo loose partsMaximum thrust: 1750NNo rotation of drill

44

1.2 PREVENT FALLING OVER

1.3 FORWARD PROPULSION

1.3.1 Activate rapid forward Distance to travel: minimummotion Maximum speed: v = 370 mm/min

Maximum air consumption:55 I/sec @ 500 kPa.Maximum sound power emission:90 dBA

1.3.2 Apply thrust Thrust needed for drilling: 1750NAir consumption for air motor 16.5 l/sAir pressure for motor: 500kPaMaximum speed for drilling: v = 370 mm/min(40 mm drill bit)Maximum air consumption: 55 l/secMaximum sound power emission: 90 dBADrill steel release mechanism

1.4 ACTIVATE DRILL

1.4.1 Activate water and air Maximum water consumption: 11 l/min@ 400kPaMaximum air consumption: 55 l/secMaximum sound power emission: 90 dBAEffective flushing of hole

1.4.2 Hole complete Depth: 1.2 – 2 m for 40 mm drill bit

45

1.5 BACKWARD PROPULSION

1.5.1 Activate rapid backward motion Minimum speed: 370 mm/minDistance to travel: 1200 mm + 100mmMaximum air consumption: 55 l/secMaximum sound power emission: 90 dBAMaximum pull: 1750NDrill steel release mechanismAir pressure for motor: 500 kPa

1.6 REMOVE DRILL Light < 30kg/personCarry handle100 – 200 (ergonomics sustained)Bright colour (bright yellow)No protruding extensionRobust (drop 0.5 m onto 50 mm steel ball –Denting not to affect function)MaintainableCorrosion resistanceNo lose itemsTwo man operation

46

DESIGN PARAMETERS FOR TELE-CONTROLS

FUNCTION DESIGN PARAMETER

1.3.1 Active rapid forward Activation of forward motion of air motormotion Sensing of speed

Sense drill position

1.3.2 Apply thrust Supply motor with air and waterSense drill speedSense drill position

1.4.1 Activate water/air Activate water to drillActivate air to drill

1.4.2 Hole complete Sense position of drill

1.5.1 Activate rapid backward Activate reverse motion on air motormotion Sense travel speed

Sense drill position

1.6 Remove drill Shut off air to motorShut off air to drillShut off water to drillSignal hole complete

47

APPENDIX C : OPERATIONAL INSTRUCTIONS, ELECTRONIC CIRCUITDIAGRAMS and PROGRAM FLOW CHARTS

48

C.1 Instructions for the Operator

Note: Throughout this document, words in italics depict control panelbuttons, valves, registers and indicator flags.

The functions present on the remote controller are depicted in Figure 7-1:Functional representation of the remote controller.

Figure 1. Functional representation of the remote controller

Normal Operation:

1. Ensure that the pneumatic and hydraulic hoses are connected to the rigsto be used.

2. Turn on the controller (Controller On). The yellow LED on the progressbar should illuminate indicating that the rig is in Standby mode.

3. Hold the Power button down for two seconds to set the rig to Operationalmode. The yellow LED on the progress bar goes out and the previoussystem settings of rod size and progress are restored. If no drill progress

49

has been made, the Cycle complete LED1 is lit up and the bottom LED inthe progress bar will flash. Release the Power button.

4. When Drill is pressed, the automatic drilling cycle commences: If the drillrod was retracted to its proper starting position, then the Cycle completeLED turns off.. The system will turn on the drill, thrust to the maximumextent of the currently specified drill rod, retract to the starting positionand turn the drill off. Upon completion of the drill cycle, the Cyclecomplete LED lights up and the bottom LED of the progress bar flashes.This process can be interrupted at any time by pressing Stop, Reverse orEmergency Stop.

5. The rig goes back into Standby mode by eiher holding the Power buttondown for two seconds, by turning off the controller (Controller Off) or bypressing Emergency Stop.

Drill steel length calibration:1. Press the Calibrate button. The drill will be advanced to the front where it

will stop. The drill steel can now be replaced.2. Pressing Rod Select will alternate LED’s between the various drill steel

sizes. Select the desired drill steel length.3. Once a drill rod has been selected, pressing Calibrate will retract the drill

to the correct position for the specified drill steel.

Notes and troubleshooting: 1. The drill steel selection option is only available between the first and

second time that the Calibrate button is pressed. During this time, boththe Drill and Reverse buttons are deactivated. If the Stop button ispressed during the calibration process, it will be aborted and the previousset-up will be restored.

2. The Emergency Stop button can be pressed at any time. When this isdone, the drill will be stopped and will enter into Standby mode.

3. Other than during the calibration procedure, the Reverse button can beused at will. The drill steel will automatically be stopped if it reaches thestarting point, that is, where the Cycle complete LED lights up. PressingReverse again can further retract the drill steel. The rear limit switch willhalt the drill if the user doesn’t press Stop in time.

4. If communication is lost between the rig and the controller the red LED ofthe bar display will flash. Each time the light flashes a Stop command isissued. If the user moves back into range, normal operation willcommence. The delay between moving into range and thecommencement of normal operation can at times be lengthy and it isadvisable to simply turn the controller off and then on again.

5. If no drill movement is detected within two seconds when the rod issupposed to be moving forward or backward, the red Jam LED will

1 Note that the cycle complete LED is currently being used as an indication of the efficiency of the rig-to-controllercommunication channel. Each time that this LED is toggled, a packet of data has been successfully received fromthe rig. The cycle complete indication could easily be reintroduced.

50

illuminate. This LED goes off when the movement commences again. Ifthere is a lack of movement , the user should press the Stop button toclear the problem.

6. If for example the pneumatic hose is connected for an extended period oftime without activation of the rig, the battery may run down. If the batterylevel drops below a specific level (10.5V) then the generator willautomatically be activated for a time sufficient to recharge the battery.The portable controller has currently no battery level monitor installed.

C.2 VALVE ARRANGEMENT

The valves present are :1. Generator On/Off2. Drill On/Off3. Thrust Forward/Reverse

These are arranged as in Figure 6-1: Valve configuration below.

Pressure Switch Generator

Generator On/Off

Drill On/Off

+_ 12V

Drill

Motor

Pneumatic inlet

(to electronics)

Forward/ReverseThrustMotor

Figure 2. The required pneumatic valves

51

C.3 Rig ElectronicsFigure 6-2: Schematic overview of electronic control layout in the drill.3provides an overview of the electrical rig constituents , a more detailed diagramis presented in Error! Reference source not found.9 at the end of thisdocument.

R X

T X

Decoder

A n t e n n a

Microprocessor

Proximi ty sensor

F r o n t swi tch

N C

12V Bat te ry

Regulator

Vcc

Pressure swi tch

B a c k switch

N C

Forward/Reverse

Dril l On/Off

DrillStop

ReverseCalibrate

Bat terycheck

ID, Progress , Jam f lagPower f lag, Stopped f lag

Power

Generator On/Of f

Power

Encoder

Figure 3. Schematic overview of the rig electronics constituents

Power is available to the electronics when the main pressure switch is closed,i.e. when the pneumatic hose is connected to the rig. A filter has beenintroduced on the pressure switch to eliminate unwanted effects such as switchbounce. Filters have also been introduced on the limit switch for similar reasons.The rig microprocessor fulfils the following functions:

1. When the pneumatic hose is connected and the portable controller has notinitiated a Power On command, the rig electronics is in standby mode, apower saving feature. In standby mode, the power to the electronics iscyclically switched on for 400 ms and then off for 800 ms. The systemremains in standby mode until the user holds the portable controller Powerswitch down for two seconds. When this occurs the system is put into

52

operational mode. In operational mode the power to the electronics iscontinuously on until the portable controller Power switch is held down fortwo seconds, or the emergency stop switch is pressed.

2. The battery level is monitored. If the battery voltage drops below 10.5 volts,then the generator is activated until the battery is charged. A regulator hasbeen fitted between the generator and battery. It converts the messygenerator output voltage (which often goes above 20 V) and regulates it to asmooth 13.8 volts for charging. Enabling and disabling the generator is doneusing the Generator On/Off valve. When the generator is turned on, thevoltage immediately rises to the 13.8V charging level. The battery voltagecan thus not be sampled while it is being charged. This is accommodated forby charging for five minutes, turning off the charger, waiting for the voltagelevel to settle, and then measuring. This process is repeated until the batteryvoltage reaches a sufficient level at which point the Generator valve isautomatically turned Off.

3. By monitoring the direction and the proximity sensor pulses, the drill positioncan be tracked. When the machine is first put into use, an initial calibrationshould be conducted to obtain the first reference. Each time the front limitswitch is pressed, the position reference is zeroed and any accumulatederror is eradicated.

4. Control of the automatic drill process. This is initiated by pressing the Drillbutton, and involves the following sequence: Drillvalve On, Forwardvalve On,front limit switch pressed, Stop, Reversevalve On. Since only the controllerknows the selected rod size, the controller issues the final stop command.This sets both Drillvalve and Reversevalve to Off.

5. Interpretation of the Stop and Reverse commands.6. Partial control of the calibration procedure for changing drill rods: Upon

receiving a Calibrate signal, thrust to the front limit and stop. Upon receivinga further Calibrate signal, retract the drill. The rod size selection and the finalStop command is issued by the portable controller.

7. The following data stream is put out onto the TX: An identity code, the drillposition, a jam indicator, a power status indicator and a flag to indicate thatthe rig has stopped. This last flag acts as confirmation after the portablecontroller sends a stop command. There is ample room to accommodateinformation regarding additional system errors.

53

C.4 Program description:

Error! Reference source not found. and Error! Reference source notfound.5 present very simplified flowcharts depicting the core features of thesoftware. Indicator flags are depicted by the suffix “_f”.

Pressure switch on

Standby Mode

Power Onsignal?

No

Operational Mode

Yes

Update Progress by monitoringMovingforwards_f, Movingbackwards_f

and the front switch.

Battery monitor routine

Interpretroutine

All valves off

Transmit ID,Progress, jam_f and

stopped_f

Initialise routine

Figure 4. Main program loop for the rig microprocessor

54

InterpretThis routine digests the signals leaving the decoderand translates them into appropriate valve actions.

Reversesignal?

Calibratesignal?

no

no

Forwardvalve Off, Reversevalve On, Drillvalve OnSet Movingbackward_f

Clear Movingforward_f, Jam_f, Autodrill_f and Stopped_f

If Halfcomplete_f is set then {Forwardvalve On, Reversevalve Off,Drillvalve On. Set Movingbackward_f. Clear Halfcomplete_f,

Calibratemode_f and Stopped_f}else

{Reversevalve Off, Forwardvalve On, Drillvalve On. Set Movingforward_fand Calibratemode_f. Clear Autodrill_f, clear Movingbackward_f and

Stopped_f}

yes

yes

Out

Out

Out

Drillsignal?

no

Reversevalve Off, Forwardvalve On, Drillvalve On Set Movingforward_f and Autodrill_f

Clear Stopped_f and Movingbackward_f,

yesOut

Stopsignal?

no

yesOut

Drillvalve OffSet Stopped_f

Clear Movingforward_f, Movingbackward_f,Autodrill_f, Halfcomplete_f and Calibratemode_f

Frontswitch?

Backswitch?

Clear Movingforward_f.If Autodrill_f is clear then {Drillvalve Off. Set Halfcomplete_f. Clear Stopped_F}else {Forwardvalve Off, Reversevalve On, Drillvalve On. Set Movingbackward_f} Out

OutDrillvalve Off. ClearMovingbackwards_f.

Emergency Stopsignal?

no

yes Standbymode

Drillvalve Off, Generatorvalve OffSet Stopped_f

Clear Movingforward_f, Movingbackward_f,Autodrill_f,Halfcomplete_f and Calibratemode_f

Figure 5. Interpret routine for the rig microprocessor

55

C.5 Controller Electronics

Each rig is controlled by a separate identical microprocessor. An electricalschematic of one of the two microprocessors is given in Error! Referencesource not found.. A more detailed diagram is presented in Error! Referencesource not found.8. at the end of this document.

Microp roces so r

R X

A n t e n n a

Progress Bar

Stop command

Lines to rods i z e L E D s

C y c l e C o m p l e t e L E D

Jam LED

Power On/Of f

Rod select bu t ton

Calibrate bu t ton

Calibrate command

EncoderReverse bu t ton

P o w e r bu t ton

Drill bu t ton

Stop bu t ton

A n t e n n a

T XD e c o d e r

Figure 5. Controller microprocessor and its peripherals

The microprocessor in the controller has the following functions to fulfil:1. Receive and interpret the data string sent by the drill rig unit (ID,

Progress, Jam_f, Power_f and Stopped_f). If no data is receivedwithin 4 seconds, flash the red LED of the progress bar and issuea Stop command.

2. If the Power button is held down for two seconds and the drill righas confirmed the power status (Power_f set) then toggle thepower on and off.

3. Store the set drill rod size and drill rod position in EEPROM.4. Update the progress bar according to the current position.

5. In both, the Drill and the Calibrate sequences, this controller isrequired to send a Stop signal to the rig when the drill hasretracted to the required position.

6. Control the Cycle complete and Jam LED’s.

56

C.6 Program description:

The program essentials are represented in Error! Reference source notfound..

Change of state interrupt on RX lineThis routine interprets the incoming data stream sent by the rigTX: Load a timer with a value corresponding to the baud rate.Disable the RX interrupt and enable an overflow interrupt for

the timer. Each time this overflows, check and record theincoming value. After 8 values have been recorded, it is

determined (by comparing to the specified ID's) from whichrig the signal originates. If applicable, the data following this is

then ingested. Finally, disable the overflow interrupt andre-enable the RX interrupt.

Update the progress bar according to theselected rod size and value in Progress.

Update the jam and cycle complete LEDs.

If Calibrate is pressed andCalibrate_f is clear then set

Calibrate_f.If Calibrate is pressed and

Calibrate_f is set then load newDrillsize and clear Calibrate_f.

If Rod Select is pressed andCalibrate_f is set, cycle throughthe rod sizes. If Stop is pressed,

restore the original rod size.

WhenProgress=Drillsize,

issue a Stop command.

Is the dataintended for this

rig?

no

yes

Power_fset?

yes

no

Controllerpower on

Startup and errorchecking code

Interpret RX data and check for communicationchannel loss. If no comms for four seconds,

flash red light and send Stop command.

Figure 6. Main program loop for one of the microprocessors in theportable controller

57

Figure 8. Schematic circuit diagram for the portable rig controller

TITLE: DATE:

PAGE:

Portable controller 19/01/01

1/2

DOC NO:

CSIR Division of Mining TechnologyPO Box 91230Auckland Park2006

Bruce Spottiswoode

FILE: Rig controller4.DSN

AUTHOR:REV: 1

SW1

DRILL_2SW14DRILL_1

SW4STOP_2

R6100k

SW5

CALIBRATE_1

SW6

REVERSE_2

SW7STOP_1

R10100k

SW8ROD SELECT_1

D1

Cycle Complete

Vd

d2

Vs

s1

RST3

U1MCP100-D

Supervisory circuit

Vdd 2Vss1

RS

T3

U2MCP100-D

Supervisory circuit

X14MHz

C1

22pF

C2

22pF

X24MHz

C3

22pF

C4

22pF

R131k

D3

Jam

R14470

D4Cycle Complete

D5 Jam

R15

470

R16

470

D6

Rod_2

R17470

D9

Rod_1

R18470

D12

Rod_3

R19470

D15Rod_4

Progress Bar 1

Progress Bar 2

R21470

Vcc2

C5100nF

C6100nF

12

J2

Rx Antenna

RF in 1

RF gnd2

CD3

0V4

Vcc5

AF6

RXD7

U6

RX2C81uF

123

45

6

J3

ICSP 1

12

J4Remove whenprogrammingprogramming

D411N4148

D42

1N4148

R74

47k

R75

47k

123

456

J5

ICSP 2

12

J6Remove whenprogrammingprogramming

C10100nF

R11100k

SW3CALIBRATE_2

+5V

R24100k

SW9ROD SELECT_2

D2

Rod_2

R76470

D7Rod_1

R77470

D8

Rod_3

R78470

D10

Rod_4

SW2

REVERSE_1

342

1

SW10POWER_2

342

1

SW11POWER_1

R80

470

R81

470

C70.22uF

C9

0.1uF

+5VSW12Main Power

+5V

+5V

+5V

+5V

D14

1N4148

D16

1N4148

R1100k

R2100k

R5

1k

1234

J8

PHONE CONN1

Data Out_1

GndData In_1

(For RS232 comms)

1234

J9

PHONE CONN2

Data Out_2

GndData In_2

(For RS232 comms)

Sw 6; pos 1Sw 2; pos 1

Sw 5; pos 2

Sw 3; pos 2

Sw 4; pos 1

Sw 5; pos 11

2

43

SW13OMRON

Vbat

R4 100k

+5V

Vbat

I1

O3

G2 U5

LP2950-05

Vbat

R224k7

R23

20k

Battery low of 5.4Vgives 4.36V here.

R82

1k

12

J10

To CN2 pin5D11

1N4148

D13

1N4148

R83

1k

MCP100-D

RS

T (

ac

tiv

e lo

w)

Vd

dV

ss

LP2950CZ-05

IGO

VN0300

S G D

OO GG II

Q1

VP0300

Q2

VP0300

Q3

VN0300

and VP0300

1

2

43 SW15

OMRON G2V-2

Vbat

Q5

VN0300 R3

1k

R8470

+5V

R9

470

+5V

12

J7

Power to TX

+5V

1

2

J11

C11

10uF

RA0/AN03

RA1/AN14

RA3/AN3/Vref+6

RB0/INT36RB1 37

RB238RB3/PGM39

RB4 41RB542

RB6/PGC 43RB7/PGD 44

MCLR/Vpp/THV2

OSC2/CLKOUT15

RC1/T1OSI/CCP218

RC2/CCP119

RC3/SCK/SCL20

RC4/SDI/SDA25RC5/SDO26RC6/TX/CK27

RC7/RX/DT29

RA2/AN2/Vref-5

OSC1/CLKIN14

Vdd1 35

Vss113

Vss234

Vdd212

RA4/TOCKL7

RA5/AN4/SS8

RE0/RD/AN59

RE1/WR/AN610

RE2/CS/AN711

RC0/T1OSO/T1CKL16

RD0/PSP021

RD1/PSP122

RD2/PSP223RD3/PSP3 24

RD4/PSP430RD5/PSP531RD6/PSP632RD7/PSP733

NC11

NC217 NC3 28

NC440

U3

PIC16F877PLCC

+5V

RA0/AN03

RA1/AN14

RA3/AN3/Vref+6

RB0/INT 36RB1 37RB2

38RB3/PGM39

RB441RB542

RB6/PGC 43RB7/PGD

44

MCLR/Vpp/THV2

OSC2/CLKOUT15

RC1/T1OSI/CCP218

RC2/CCP119

RC3/SCK/SCL20

RC4/SDI/SDA25RC5/SDO26RC6/TX/CK27

RC7/RX/DT29

RA2/AN2/Vref-5

OSC1/CLKIN14

Vdd135

Vss113

Vss2 34

Vdd212

RA4/TOCKL7

RA5/AN4/SS8

RE0/RD/AN59

RE1/WR/AN610

RE2/CS/AN711

RC0/T1OSO/T1CKL16

RD0/PSP021

RD1/PSP122 RD2/PSP2 23RD3/PSP3

24

RD4/PSP4 30RD5/PSP5

31RD6/PSP632RD7/PSP733

NC11

NC217

NC328

NC440

U4

PIC16F877PLCC

R12

1k

D43

1N4007

D44

1N4148

Vbat

J1P2LEDa

J12P2LEDc

J13P1LEDa

J14P1LEDc

J15

Vbat

J16

Power2

J17

Power1

J18

Gnd

J19Cal2

J20Cal1

J21Stop2

J22

Rev2

FROM 4.3V SUPPLY

J23

+4.3V

Sw 1; pos2Sw 4; pos2

Sw 1; pos1

Sw 3; pos1

J24D7c

J25

D7a

J26D2c

J27

D2a

J28D8c

J29

D8a

J30

D10a

J31

D10c

J32RSel1

J33Cal1

J34RSel2

J35Cal2

J36Sw15

J37

Sw13

J38D6a

J39D6c

J40D9a

J41D9c

J42D12a

J43D12c

J44

D15a

J45 D15c

J46Stop1

BAT14x1.5V(AA cells)

1

2

J47

Q?

VP0300

G2V-2

R?1M

Q?

VP0300

R?1M

R? 100kD?1N4148

D?1N4148

R? 100k R? 100k

q[1..12]

p[1..12]

Gnd

Gnd

Vpp_1

Vdd_1

RXdata_2

RXdata_1

CalibrateOut_1

Clk_1

Complete_1Jam_1 p8

p7p6p5

xmit_1rcv_1

p11

p10p9

p4

p3p2p1

+5V

+5V

p12

Powerin_2

CalibrateOut_2

Clk_2

Complete_2Jam_2 q 8

q 7q 6q 5

xmit_2rcv_2

q12q11

q10

q 9

q 4q 3

q 2q 1

Batcheck_2

Batcheck_1

Select_2

Data I/O_2

Data I/O_1

Select_1

Vdd_2

Vpp_2

CalibrateIn_1RodSelect_1

RodSelect_2

Powerin_1

Powerout_2

Powerout_1

Rev1

Rod1_2Rod2_2Rod3_2Rod4_2

CalibrateIn_2

Rod2_1Rod1_1

Rod3_1Rod4_1

Stop_1

GND

Drill1

Stop_2

Drill2

58

Figure 9. Schematic circuit diagram for the electronics housed in the rig

TITLE: DATE:

PAGE:

Drill rig controller 20/08/01

1/2

DOC NO:

CSIR Division of Mining TechnologyPO Box 91230Auckland Park2006

Bruce Spottiswoode

FILE: Rig Electronics4.DSN

AUTHOR:REV: 1

X2

20MHz

C322pF

C4

22pF

R13

1k

RA0/AN02

RA1/AN13

RA3/AN3/Vref+5

RB0/INT21

RB122

RB2 23

RB3/PGM 24

RB425

RB526

RB6/PGC 27

RB7/PGD 28

MCLR/Vpp/THV1

OSC2/CLKOUT 10

RC1/T1OSI/CCP212

RC2/CCP113

RC3/SCK/SCL14

RC4/SDI/SDA15

RC5/SDO16

RC6/TX/CK17

RC7/RX/DT18

RA2/AN2/Vref-4

RC0/T1OSO/T1CKI11

OSC1/CLKIN 9

RA5/AN4/SS 7RA4/TOCKI 6

Vdd20

Vss18

Vss219

U1

PIC16F873

123456

J1

ICSP

+5V

12

J2Remove when programming

D1

1N4148

R1

47k

Vdd

2V

ss3

RST1

U2MCP100-300

+5V

I1

O3

G2

U3LM7805

12

J4

BATTERY

+12V +5V

+5V Vcc5

R210k

R310k

+5V

C10.22uF

C20.1uF

R491k

R5130k

+12V

12

J6

IFRM 18X9503

RF out2

RF gnd1 Vcc 3

TXD 5Gnd4

U4

TX2

Vcc5

12

J7

Antenna

C5100nF

Supervisory circuit

R61k

Q1

VP0300

R710k

+5V

Vcc12 +12V

Vcc12

R11100k

C6 100nF

C710uF

D51N4007

R15100k

Q30VN0300

R16

100k

R17100k

Proximity sensor

Q31VP0300

R1891k

R1982k

R2091k

R2182k

R2291k

R2382k

R2491k

R2582k

R7491k

R7582k

1234

J5

PHONE CONN

Data Out

GndData In

SW3

Hydraulicpressure?

RE

CE

IVE

R

D71N4007

+12V

(for RS232 comms)

Q2VP0300

R8091k

R8182k

R8291k

R8382k

R8491k

R8582k

Rig 1 (R1): Power=u1 NAND u2 (u1 & !u2)Drill=d1 NAND d2Stop=e1 NAND (e2+w2)Reverse=(ns1 NAND (n2+s2))Calibrate=(e2+w2) AND e1

Rig 2 (R2): Power=u1 AND u2 Drill=d1 AND d2Stop=w1 NAND (e2+w2)Reverse=(sn1 NAND (n2+s2))Calibrate=(n2+s2) AND sn1

1

2

43

SW4RELAYC

R8691k

R8782k

123456789101112

J3

To Receiver

1234

J8

Emergency Stop

1234

J9

D21N4007

D31N4007

D41N4007

To Valves

R78

1k

12

J1112

J12Front switchBack switch

Q3

FET

R8100k

R910k

Q4

FET

R10100k

Q5

FET

R12100k

Q6

FET

22UF

D6

1N4148220K100k

Debounce: 200ms rise to 2V

R14

1k

C8

D8

1N4148R26100k

+5V

VN0300/VP0300

S G D

C9220uF

Gnd

Battery check

4.94 volts

TX Data

Counts

+12V

Switch5Switch 12

Vpp

u1 (R1 and R2)u2 (R1 and R2)d1 (R1 and R2)d2 (R1 and R2)R1: e1 R2: w1e2+w2 (R1andR2)R1:ns1 R2:sn1n2+s2 (R1andR2)

Emergency

To k13 or k14

For

war

d/S

top

Reverse

Pow

er O

n/O

ff

Rev

erse

/Sto

pD

rill O

n/O

ff

Back

Vdd

Front

Gnd