Automated Electromagnetic Crane

1
Automated Electromagnetic Crane

• Greg DeKing
• Fran Simmonds

2
Principles of Design

• Functionality
• Mechanical Design
• Sensor Design
• Embedded Design
• Cost
• Problems
• Questions

3
Functionality

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

4
Specifications

• Runs 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.

5
Limitations

• All 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.

6
Designer imposed constraints

• High success rate.
• Sensors.
• Low cost.
• Stationary.
• Battery power.

7
Components

• HC12
• Duramag ER1-071 Electromagnet
• 3 12V Stepper Motors
• 8 74151 8-1 Mux
• OPB 745 Optoisolator

8
Duramag ER1-071 Electromagnet
9
Motors

• 12V Airpax stepper motor
• 2 12V NMB stepper motors
• Stepper interface boards

10
Optoisolator

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

11
Mechanical Design
12
Mastercam side view
13
Mechanical Design
14
Tower Support
15
Mastercam -- top view
16
Sensor Placement
17
Sensor Design

• Conductive rings separated by non-conductive
  material
• Inside rings of row in series
• Outside rings of column in series

18
Sensor Function

• Input signal applied to inner ring
• Block completes circuit
• Corresponding mux control
• HC12 reads voltage hit

1 0
19
Interfacing
HC12
PORT A
PORT B
PORT T
PORT AD
PORT P
8
8
3
4
PAUSE
MULTIPLEXER SYSTEM
8
MOTOR CONTROL BOARDS
OPTOISOLATOR
SENSORS/ TARGET AREA
MOTORS
DIRECTION
DISTANCE
VERTICAL
20
MULTIPLEXER SYSTEM
PORT AD
3
8-1
8-1
8-1
8-1
8-1
8-1
8-1
8-1
COLUMN 0-7
8
SENSORS / TARGET AREA
21
Sensor Map

• 37 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.

22
Embedded Design

• begin read AD
• store AD in TEMP
• change MUX controls
• Loop ITERATION 1
• bit test bit 0
• branch bit not set to next
• set bit MAP_POINTER BIT_POINTER
• next MAP_POINTER 1
• Shift TEMP
• Test ITERATION
• branch less than 8 to loop
• ITERATION 0
• Test MAP_POINTER
• Branch less than 37 to begin
• BIT_POINTER 1
• Test BIT_POINTER
• Branch less than 8 to begin
• BIT_POINTER 0

23
Foreseeable Problems

• Multiplexing of I/O.
• Blocks contacting multiple sensors.
• Two Blocks on same sensor.

24
Cost

• Electromagnet 40.00
• Motors 15.00
• Circuit Boards 30.00
• Muxs 15.00
• Aluminum 60.00
• Total 180.00

25
Questions

• Any Questions ?