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sbgisen / vesc

VESC Interface for ROS
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[vesc_hw_interface]enforceLimits() using fixed control period(100Hz) #68

Closed nyxrobotics closed 1 year ago

nyxrobotics commented 1 year ago

Abstract

I'm not sure if there is any change in functionality, but looking at the source code, it is odd, so I'm making an issue.

https://github.com/sbgisen/vesc/blob/d96dcc2d81419f33647b37b249769c0101b7b7f5/vesc_hw_interface/src/vesc_hw_interface.cpp#L244 https://github.com/sbgisen/vesc/blob/d96dcc2d81419f33647b37b249769c0101b7b7f5/vesc_hw_interface/src/vesc_hw_interface.cpp#L299-L302

Control rate is specified as a parameter in vesc_servo_controller and vesc_wheel_controller https://github.com/sbgisen/vesc/blob/d96dcc2d81419f33647b37b249769c0101b7b7f5/vesc_hw_interface/src/vesc_servo_controller.cpp#L55-L56

https://github.com/sbgisen/vesc/blob/d96dcc2d81419f33647b37b249769c0101b7b7f5/vesc_hw_interface/src/vesc_wheel_controller.cpp#L39

How to Reproduce the Bug

Problem due to the Bug

Factors

Suggestion

nyxrobotics commented 1 year ago

Investigating general implementation. I will try using the argument "period" in write() function.

https://github.com/ros-controls/ros_control/wiki/joint_limits_interface

jsupratman13 commented 1 year ago

To elaborate, the enforceLimits control period and the hardware interface node control period are fixed at 100Hz, as shown below: https://github.com/sbgisen/vesc/blob/1e6ed15aabc3756af8b5e692b08b2e44cb6fdcb8/vesc_hw_interface/src/vesc_hw_interface_node.cpp#L29-L40 https://github.com/sbgisen/vesc/blob/d96dcc2d81419f33647b37b249769c0101b7b7f5/vesc_hw_interface/src/vesc_hw_interface.cpp#L244 https://github.com/sbgisen/vesc/blob/d96dcc2d81419f33647b37b249769c0101b7b7f5/vesc_hw_interface/src/vesc_hw_interface.cpp#L299-L302

The above should be ok, however, the sample implementation, given in https://github.com/ros-controls/ros_control/wiki/joint_limits_interface, shows the enforceLimits taking control period passed from the write function. In addition, the combined hardware interface sample file also shows the control period passed on to the write function.

Therefore, instead of defining the ros_control's control period on vesc hw interface, better to use the control period given in hardware_interface_node layer.