Rear wheel speed control of the Desktop Robotti V.2.

Success criteria

By publishing movement commands trough a ROS2 topic, the speed of the rear wheels of the Desktop Robotti V.2 can be controlled. Furthermore, a performance specification of the robots velocity control must be outlined in an accompanying document, which includes:

1. Max velocity
2. System response time, i.e time to reach target velocity in a static environment
3. Velocity measurement resolution and delays

Milestone description

The functionality to be implemented spans both the MCU microtroller and Raspberry Pi 4 onboard the DRobotti V.2:

1. Robot speed and direction is controlled by the two rear wheel motors on the DRobotti V.2
2. The velocity of the motors is managed by the MCU motorcontroller board onboard the Desktop Robotti V.2
3. The MCU board receives velocity targets for each rear wheel motor from the Raspberry Pi through a serial link
4. The Raspberry Pi computes the velocity targets for each motor from movement commands transmitted on the ROS2 Network

Furthermore, in order to ensure ROS compatibility, and allow for interfacing to teleoperation/autonomous navigation, the topic type must be defined:

• Movement command topic is of type AckermannDriveStamped, http://docs.ros.org/en/jade/api/ackermann_msgs/html/msg/AckermannDriveStamped.html