Cambridge Researchers Use Fleet of Mini Cars for Cooperative Driving Experiments

Researchers from the University of Cambridge have tasked a fleet of 16 Ackermann-steering vehicles for use in cooperative driving experiments and autonomous control strategies. Their experimental testbed, with multi-lane freeway, enables them to implement state of the art driver models and test their validity in the real world.

“Our experimental testbed allows us to implement state-of-the-art driver models as well as autonomous control strategies, and test their validity in a real, physical multi-lane setup. Through experiments on our miniature highway, we are able to tangibly demonstrate the benefits of cooperative driving on multi-lane road topographies. Our setup paves the way for indoor large-fleet experimental research.”—Assistant Professor (Lead Researcher) Amanda Prorok

Developing and building true-scale facilities are costly — a great example is the University of Michigan’s Mcity Test Facility, which cost $10 million to create and covers 32 acres, and while it’s an excellent testbed, larger doesn’t necessarily mean better. Rather than use actual vehicles, the researchers designed a fleet of “Minicars,” or 1:24 scale Range Rover Sports, each outfitted with a Raspberry Pi Zero W, forward drive train, micro servos, L293D H-bridge, and AA batteries for power.

Each vehicle employs an OptiTrack motion-capture system, several passive reflective markers, and lane topography to provide real-time feedback on the vehicle’s position. A path-planning algorithm uses the position feedback to compute trajectories for each car, which are then transmitted to them over Wi-Fi.

The testbed can be used to implement different driver models and autonomous control strategies, allowing the researchers to evaluate the vehicles in a more realistic sense instead of using actual vehicles. Testing using the platform showed cooperative driving can increase throughput by 42%, which the researchers find encouraging, and could further research in multi-car navigation and cooperative driving.