Mastering ROS for Robotics Programming - Second Edition

Computing motor velocities from ROS twist message

The C++ implementation of twist_to_motor.py is discussed in this section. This node will convert the twist message (geometry_msgs/Twist) to motor target velocities. The topic subscribed by this node is the twist message from the teleop node or Navigation stack and it publishes the target velocities for the two motors. The target velocities are fed into the PID nodes, which will send appropriate commands to each motor. The CPP filename is twist_to_motor.cpp, and you can get it from the chefbot_navig_cpp/src folder:

TwistToMotors::TwistToMotors() { init_variables(); get_parameters(); ROS_INFO("Started Twist to Motor node"); cmd_vel_sub = n.subscribe("cmd_vel_mux/input/teleop",10, &TwistToMotors::twistCallback, ...