April 26, 2001

Team Information

Designation

Ongo-03

Members

Advisors Dr. J. Lamont, Prof. R. Patterson,

Dr. Rajagopalan, Dr. J. Basart

Client Space Systems Operational Lab (SSOL)

Second Semester• Cory Carlson• Nick Lindstrom• Brian Peres• John Dorsey• Zach Smith

First Semester• Scott Dang• Chad Winterhof• Eugene Koob• Bernard Lwakabamba• Stephen Smith• Nathan Ellefson

• Problem Statement & General Background • Project Assumptions and Limitations • Design Objectives/Constraints• End-product Description• Risk and Risk Management• Technical Approach• Evaluation of Success• Future Work• Financial and Human Budgets• Lessons Learned• Summary

Agenda

General Background

• Annual competition started in 1990• Sponsored by the Association for Unmanned

Vehicle Systems International• University teams build autonomous aerial vehicles

that must complete predetermined tasks• Tasks change every 4 to 5 years• The team completing the most tasks in the least

amount of time wins

IARC (International Aerial Robotics Competition)

Problem Statement

• Build ISU’s first entry in IARC competition– Complete the requirements for the competition

• Modify an R/C helicopter for autonomous flight

• Establish a communication link between the helicopter and a ground-based PC station

End-product Description

• Fully autonomous gas powered helicopter that uses GPS and other sensors to navigate

• The ability to transmit analog image signals to a ground station

• Ground station able to recognize symbols via image recognition software

• Able to enter the IARC

Assumptions

• Funding will be available for the completion of the project

• Suitable hardware will be available to complete the project

• Our design will successfully control the flight of the helicopter used in the project

• The sensors chosen for the helicopter will work with the control system to control the helicopter and successfully identify ground markings

Limitations

• The payload carrying capacity of the helicopter• Flight time of the helicopter without refueling• Accuracy of the GPS system• Range of the imaging hardware• Range and accuracy of the data transmission

equipment• Available funding• Limited mounting surface• Power consumption

Potential Risks

• Serious design flaw that halts the development of the aircraft

• Helicopter crashes and needs repair

• Our funding runs out before the project is finished

• Time constraints, rule changes

Current Semester Approach

1. Split into three groups:

• System Requirements

• Controls

• Communications

2. Develop a strategic plan (team handbook)

3. Allocate and specialize responsibilities

Technical Approach

• We are planning to use a PC/104 control board as the on-board computer to control the helicopter.

• This controller will be interfaced with the sensors and telemetry.

• It will take data from the sensors and process it so that it can make flight control decisions.

• The control subsystem will reside in the software of the onboard computer.

Control Subsystem

Technical Approach

Autopilot Servos Helicopter Reaction

AFCS Inner Loop

AFCS Outer Loop

Figure 1. Simple block diagram showing control system interaction with helicopter

Control Subsystem

Technical Approach

Control Subsystem

Model Helicopter

Logic

Sensors

Position

Desired Position

Sensors Subsystem

Sensor System

ONBOARD COMPUTER

•Polls the SLAVE(s) in a predefined order

•Packages sensor data and sends to the telemetry subsystem

SLAVE (PIC)

•Performs A/D conversions if necessary

•Performs segmentation of data

•Controls operation of servos

Technical Approach

SLA

VE

SENSOR ANALOG

SLA

VE

SENSOR ANALOG

1

2

AD

DIT

ION

AL S

EN

SO

RS

DIGITALCPU

Technical Approach

Sensors Subsystem

Current Sensor Components

• Polaroid 6500 Ranging Module (2) Altitude & Proximity• Accelerometers (2) Acceleration• Gyroscopes (2) Pitch, Yaw, Roll• Digital Compass Direction

Future Sensor Components

• GPS Global Coordinate• Imaging System Image Recognition

Technical Approach

-Telemetry Unit-

• It will interface with the on-board computer.• This subsystem will relay flight and mapping information

to the PC based ground station for processing.

-PC Based Ground Station-

• The ground station will receive and log sensor data from the telemetry system on the helicopter.

• It will also do image recognition on the image relayed from the helicopters on-board video camera.

• We have chosen a Dell 500 MHz PC for this job.

Information Transfer and Processing

Evaluation of Success

Goals completed:

• Learned to program PICs

• Designed basic control algorithm

• Created new strategic plan

• Designed communications for onboard components

• Created interfaces between sensors and PICS

Evaluation of Success

Past accomplishments

• Built and tested helicopter

• Designed compass circuit

• Created sonar software

• Acquired ground station

• Acquired flight simulator

Future Work

Future Milestones:– Test hardware limitations

– Finish development on control/communication software

– Learn to fly helicopter manually (ongoing)

– Start assembling hardware to mount onto the helicopter

– Repair the helicopter

Expected Financial Budget

Item Description Estimated Expense ($) Actual Cost ($) Helicopter/controller 2000 1800 2 Sonar sensors 150 100 2 Accelerometers 60 60 3 Gyroscopes 50 50 PIC Processors 300 10/PIC GPS Unit 700 N/A Digital compass 80 100 Telemetry Unit 1000 N/A Onboard computer 560 N/A Camera / Image s/w 2500 N/A Miscellaneous Parts 300 50 Base Station CPU 1600 1600

Total 9300 3810

Human Budget

Activity Estimated (Man Hours) Actual (Man Hours) Research PIC Controllers 110 90 Sensor Subsystem Design 220 140 Group Meetings 200 352 Project Plan 15 17 Poster Design 5 6 Presentation 15 20 Prepare Strategic Plan 25 40 Design PIC/PC Communications 150 120 PIC/Sensor Interfacing 60 90 Total 800 875

Lessons Learned

• Team work• Meet regularly• Interpersonal communications• Thoroughly document work done• Know the project requirements• Work always takes longer than planned• RISC architecture can be confusing• I/O operations are easier in assembly than C++• Double check contacts

Summary

Goal: Build autonomous vehicle for entry in IARC competition by 2003

Proposed Solution: Modify a gas-powered remote controlled helicopter for autonomous flight

Current Status: 1. Helicopter built and flight tested

2. Sensor subsystem in the implementation phase3. Control system entering design phase

Questions

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