Brake Bypass - Quanser 6 DOF Hexapod Laboratory Manual

Note: The Slider Gain values are actually reset to the home reference automatically when the controller is
stopped. The signal amplitude gains are all reset to 0 and the frequency gain blocks are set back to 1 Hz.
However, because this is performed after the controller is stopped, it does not physically move the platform
back to HOME. This must be done manually as the controller is still running.
10. Click on Stop button in the Simulink diagram tool bar to stop running the controller.
11. Shut off the Hexapod power switch if no more experiments will be conducted.
Note: As explained in the Hexapod User Manual [2], if a limit switch is triggered the amplifier automatically stops
accepting any motor/joint commands in that direction. However, position commands in the opposite direction are still
accepted (e.g., joint can be moved back to home).
The measured end-effector position, from the Forward Kinematics block is shown in the World Position (mm) display
block. The measured joint positions are shown in the Joint Position display.

2.5 BRAKE BYPASS

The Hexapod_Brake_Bypass.mdl model, shown in Figure 2.7 allows the joints to be moved manually. The amplifier
drives are enabled and the brake system is disabled when the Digital Output Channels #12 and #13 are set to 0
and 1, respectively. The amplifiers are disabled when the DO #12 and #13 are both set to 1. The joints can be
moved manually as long as the amplifiers are enabled (and no internal amplifier faults, such as over-current or
over-temperature are triggered).
Figure 2.7: Simulink model used to disengage brakes on the Hexapod using QUARC
Follow these steps to disengage the brake system:
1. Make sure the red button is in the upper position to enable the amplier. The amplier cannot be enabled when
the button is in the lower position. Twist the button to ensure it is in the enabled position.
2. Open the Simulink model called Hexapod_Brake_Bypass.mdl, shown in Figure 2.7.
3. Run setup_hexapod.m in MATLAB (note: script is ran automatically when Simulink model is ran)..
HEXAPOD Laboratory Guide 12