Download Senior Design Final Documentation

absolute minimum completion of the build phase, no real system evaluation was
performed.
Chapter 10 EEL4915 Design Implementation
10.1
System Final Design Summary
6+1 DOF (6 rotational + 1 translational) robot arm
Added wrist and elbow to original AL5D
3 6-axis gyro-accelerometers (custom pcb) 3.3V
1 Shared DC Power bus servo power supply
PC power supply 5V to servo connector board
3.3V to sensors and mcu
1 Micro-controller board (custom pcb) 3.3V
1 Button gripper controller 3.3V
No wireless
The final design implemented in eel4915 in the spring of 2013 features both the
wrist and elbow upgrades (additional joints) considered in eel4914 from the fall of
2012. Wireless operation was not able to be implemented because of time
constraints. The completed design is a 6+1 DOF haptic robotic arm controlled by
3 InvenSense 6-axis gyro-accelerometers (mpu-6050) driving six 6V (4.8 – 6.0
volts) servo motors of varying torque capacity. A seventh servo controlling the
opening and closing of the end-effector (gripper) was controlled by a button
trigger arrangement held within the human operator’s palm of his hand. All
sensor signals are input to the ATxmega128A4U microcontroller unit and all
output signals sent directly to the servo motors. A pc supply power was
configured as a Shared DC Power bus servo power supply to energize all seven
servo motors and all sensors and the microcontroller unit. Basic working
amperage is about 3 to 4 amps; however, if the six rotating servos all went into
stall at once, current demand could exceed 9 amperes.
10.2
System Construction
Final construction is best explained with the following photos showing the
vertically mounted arm and adapted personal computer power supply connected
to the servo and sensor control board. The sensor sleeve connects the sensor
inputs to the mcu board and the mcu board outputs signals to the servo control
board.
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