Component Descriptions - Quanser 2 DOF Planar Robot User Manual

Note: Components 8 and 9 are not shown as they are hidden by the case.

2.2 Component Descriptions

2.2.1 DC Motor with Harmonic Drive
The motor used to drive the five-bar mechanism is a Maxon DC motor (118752) attached to a harmonic drive with
gear ratio 50:1. Harmonic drives provide gearing with zero backlash. The motors are referred to as 'left' and 'right'
in this manual and are labeled accordingly on the above figure.
Caution: High-frequency signal applied to a motor will eventually damage the gearbox motor and the motor
brushes. The most likely source for high frequency noise is derivative feedback. If the derivative
gain is set too high, a noisy voltage will be fed into the motor. To protect your motor, you should
always band limit your signal (especially derivative feedback) to a value of 50 Hz.
Caution: Input ±24 V, 3 A peak, 1.16 A continuous.
2.2.2 Incremental Encoder
The encoders used to measure the motor's angular position are rotary incremental encoders from US Digital's E5
series. The encoders have 1024 counts per revolution (CPR) and are read in quadrature mode by the DAQ resulting
in 4096 counts per revolution.
Caution: Make sure you connect the encoder directly to your data-acquistion device and not to the power
amplifier.
2 DOF PLANAR ROBOT User Manual
Figure 2.2: 2 DOF Planar Robot Components
DRAFT - September 6, 2013