Driving Ridgeback

There are four ways to drive Ridgeback, and each way will work on a physical Ridgeback robot as well as on a simulated Ridgeback.

The first two ways are teleoperation using a remote controller, and manually through publishing ROS messages. These two ways are covered in this section.

The third way is using the interactive controller in rviz. This is covered in the Simulation section.

The fourth way is through autonomous navigation. This is covered in the Navigation section.

Safety Precautions

Warning

Ridgeback is capable of reaching high speeds. Careless driving can cause harm to the operator, bystanders, the robot, or other property. Always remain vigilant, ensure you have a clear line of sight to the robot, and operate the robot at safe speeds. We strongly recommend driving in normal (slow) mode first, and only enabling turbo in large, open areas that are free of people and obstacles.

Driving with Remote Controller

Note

For instructions on controller pairing, see Pairing Controller.

To drive the Ridgeback, Axis 0 controls the robot’s steering, Axis 1 controls the robot’s left/right translation, and Axis 2 controls the robot’s steering. Buttons 4 and 5 act as enable and enable-turbo respectively. On common controllers these correspond to the following physical controls:

Axis/Button	Physical Input	PS4	F710	Xbox One	Action
Axis 0	Left thumb stick horizontal	LJ	LJ	LJ	Drive forward/backward
Axis 1	Left thumb stick vertical	LJ	LJ	LJ	Drive left/right
Axis 2	Right thumb stick horizontal	RJ	RJ	RJ	Rotate
Button 4	Left shoulder button or trigger	L1	LB	LB	Enable normal speed
Button 5	Right shoulder button or trigger	R1	RB	RB	Enable turbo

You must hold either Button 4 or Button 5 at all times while driving the robot.

Driving with ROS Messages

You can manually publish geometry_msgs/Twist ROS messages to either the /ridgeback_velocity_controller/cmd_vel or the /cmd_vel ROS topics to drive Ridgeback.

For example, in terminal, run:

rostopic pub /ridgeback_velocity_controller/cmd_vel geometry_msgs/Twist '{linear: {x: 0.5, y: 0.0, z: 0.0}, angular: {x: 0.0, y: 0.0, z: 0.0}}'

The command above makes Ridgeback drive forward momentarily at 0.5 m/s without any rotation.

Emergency Stop

Ridgeback has four E-Stop buttons located on the four corners of the robot. Pressing any of these buttons will cut power to the motors. To disengage the E-Stop, simply twist the button in the direction indicated by the arrows, and press the reset button on the rear of the robot.

Whenever you need to perform maintenance on Ridgeback, we recommend engaging the E-Stop if the robot cannot be fully powered down.