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Electronics and Power Distribution
AME 470: Senior Design
ASME Bulk Material Transporter
Matt Bertke, Paul DeMott, Patrick Hertzke, Will Sirokman
4 November 2004
Electronics
Circuit Diagram
Senior Design: Team Burja
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Electronics
Senior Design: Team Burja
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Control Box
The following controls will be
mounted on the control box:
2 Slide Potentiometers Control Motors
Mouser Part 312-9201; 5K linear, 45 mm travel
6 Pushbutton Switches
Functions: algorithm ascend, algorithm descend, swing arm
manual fwd, swing arm manual reverse, dump rice, reset
Jameco Part 26622; momentary pushbutton
1 Master Switch
Jameco Part 196154CR; rocker switch
Electronics
Senior Design: Team Burja
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Onboard
The following controls will be
onboard:
Fuse and Fuse Holder
2 9V and 9 AA Batteries and Holders
1 Rotary encoder and associated gears. Quadrate (incremental)
output.
Electronics
Senior Design: Team Burja
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Processors
The control box is connected to the Mini-Max Processor.
The Mini-Max, in turn, connects to 3 H-Bridges, which each
power one motor.
H Bridge
Mini-Max
Electronics
Senior Design: Team Burja
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Control Philosophy
Philosophy
The system will be designed to incorporate automation for
precision and ease of use, but will include operator feedback
and human control.
• Drive motors
Slide pots allow independent motor control with reverse,
neutral, and variable forward speeds.
• Swing arm
The rotary encoder senses arm angle and microprocessor
drives motor for fully automated operation. Manual override
switch available to operator.
• Dumping mechanism
Pushbutton control activates solenoid and releases door latch.
Electronics
Directions as viewed from side, with
back to the left, front to the right
Logic/Program Structure
Start
Blue shading
denotes loop
Processor converts analog input from pots to
forward/neutral/reverse PWM for treads
Function button pressed
Descend pressed
Dump
pressed
No
Ascend pressed
Electronics
Electronics
Electronics
Discharge
Rice dump pressed
Solenoid is energized by
completion of circuit during
press
Return to start
Note
This action does not interrupt the
driving microprocessor sequence; the
solenoid is not connected to the
microprocessor
Interrupt Buttons
RESET
•
The program returns
to START
•
The drive motors are
not affected
•
If not at horizontal,
swing arm should be
returned to the
position via manual
control
•
MANUAL OVERRIDE
(REVERSE)
MANUAL OVERRIDE
(FORWARD)
Calls a subroutine where:
Calls a subroutine where:
•
The swing arm motor is
driven reverse as long
as button is held down.
•
The swing arm motor is
driven forward as long
as button is held down.
•
Neither swing arm
algorithm nor drive
motors are not
affected; there is no
reset. Motors remain
controllable via the
potentiometers.
•
Neither swing arm
algorithm nor drive
motors are not
affected; there is no
reset. Motors remain
controllable via the
potentiometers.
•
Upon release of the
button, the subroutine
exits and the program
resumes.
•
Upon release of the
button, the subroutine
exits and the program
resumes.
•
Note: Operator should
not initiate manual
override while the
processor is driving the
swing arm without first
pressing RESET.
•
Note: Operator should
not initiate manual
override while the
processor is driving the
swing arm without first
pressing RESET.
Swing arm algorithm
will be restarted on the
button press.
Electronics
Senior Design: Team Burja
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Location of components
The electronic components will be placed on the chassis below
the rice bin.
• There is flexibility
regarding the
horizontal
placement of
electronic
components such
as battery packs.
• They will be
located as needed
to effect the
proper center of
gravity. Expected
location is shown
in the figure.
Electronics
Senior Design: Team Burja
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Power distribution
Replacement
It is anticipated that the 9V batteries will last for the duration of
the 10 minute competition, while the AA batteries will likely be
replaced halfway through. To ease this process, two 8 AA
Battery holders are purchased. Each will have a pinned
connector which can be plugged and unplugged for easy
transfer.
Pulse Width Modulation
Pulse width modulation allows motors to operate at reduced
average voltage while maintaining torque without increasing
current draw.
Power Management
To maximize available power to the motors, the 12V from the
AA batteries are used solely to power the motors. All other
power is provided by the 9V batteries. All allowed batteries are
used.
Electronics
Senior Design: Team Burja
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Power distribution
Energizer E91
Alkaline
Energizer NH15
Rechargeable