Automated Electromagnetic CraneGreg DeKingFran Simmonds

Principles of DesignFunctionality Mechanical DesignSensor DesignEmbedded DesignCostProblemsQuestions

FunctionalityThe Automated Electromagnetic Crane locates, acquires, and removes steel blocks from a target area to a designated container in an uninterrupted sequence.

SpecificationsRuns in fully automated mode.User may pause operation and move blocks.All blocks are relocated after every grab operation.Closest-to-bucket order of pickup.

LimitationsAll blocks must be fully inside target area.If a block is dropped the drop operation will still proceed.Blocks must be of a conductive material with a strong magnetic field.

Designer imposed constraintsHigh success rate.Sensors.Low cost.Stationary.Battery power.

ComponentsHC12Duramag ER1-071 Electromagnet3 12V Stepper Motors8 74151 8-1 MuxOPB 745 Optoisolator

Duramag ER1-071 Electromagnet

Motors12V Airpax stepper motor2 12V NMB stepper motorsStepper interface boards

Optoisolator Inductive spike caused from switching magnet off.25.5 Volt magnitude.Separate 12V source.Magnet on/off controlled by optoisolator circuit.

Mechanical Design

Mastercam side view

Mechanical Design

Tower Support

Mastercam -- top view

Sensor Placement

Sensor DesignConductive rings separated by non-conductive materialInside rings of row in seriesOutside rings of column in series

Sensor FunctionInput signal applied to inner ringBlock completes circuitCorresponding mux controlHC12 reads voltage hit

Interfacing

MULTIPLEXER SYSTEM

Sensor Map37 bytes.Each byte 1 Column.Each bit represents row number.Sensor sweep will fill sensor map one row at a time.When all 37 columns for each row complete next row will begin.

Embedded Designbegin read AD store AD in TEMPchange MUX controlsLoopITERATION += 1bit test bit 0branch {bit not set} to nextset bit MAP_POINTER + BIT_POINTERnextMAP_POINTER += 1Shift TEMPTest ITERATIONbranch {less than 8 } to loopITERATION = 0Test MAP_POINTERBranch { less than 37 } to beginBIT_POINTER += 1Test BIT_POINTERBranch {less than 8} to beginBIT_POINTER = 0

Foreseeable ProblemsMultiplexing of I/O.Blocks contacting multiple sensors.Two Blocks on same sensor.

CostElectromagnet $40.00Motors$15.00Circuit Boards$30.00Muxs$15.00Aluminum $60.00Total$180.00

QuestionsAny Questions ?