About | Support | Discussion Forum | Index | Service Status | ros @ Robotics Stack Exchange

Joint Velocity Controller

Overview

The Joint Velocity Controller commands a desired velocity to the joint. The velocity is controlled using PID control to specify the effort to the joint. When started, the controller will command a velocity of zero.

The commands from the velocity controller will be subject to the safety limits of the robot, so the velocity will not be achieved near the joint limits.

ROS API

Subscribed Topics

command (std_msgs/Float64)

• The velocity to command

Parameters

joint (string, default: Required)

• The joint to control

pid/p (double, default: Required)

• The proportional gain relating efforts to the error in velocity

pid/d (double, default: 0.0)

• Derivative gain

pid/i (double, default: 0.0)

• Integral gain

pid/i_clamp (double, default: 0.0)

• Bounds enforced on the integral windup

Example configuration:

elbow_flex_velocity_controller:
  type: JointVelocityController
  joint: r_elbow_flex_joint
  pid:
    p: 5.0
    i: 20.0
    i_clamp: 100.0