Longitudinal Control of Commercial Heavy Vehicles: Experimental Implementation

The report describes the results of the project funded under MOU 314.The main result is the experimental implementation of various longitudinal control algorithms that were developed under MOU124 and MOU 240. In order to conduct these experiments, in collaboration with Professor Tomizuka’s group and PATH Personnel, we first outfitted a Class-8 tractor-trailer commercial heavy-duty vehicle on loan from Freightliner Corporation with the necessary sensors and actuators for fully automated operation. These sensors and actuators included the vehicle speed sensors, air-brake pressure sensors, air-brake actuators, and the throttle actuator. Then, a series of open-loop and closed-loop experiments were carried out at Crow’s Landing test field. In the open-loop experiments, we identified and collected important parameters for vehicle dynamics such as the working ranges for the brake and fuel actuators, the vehicle speed signals, and the air-brake pressure signals. These parameters enabled us to evaluate the vehicle dynamics and adjust the control algorithms accordingly, tuning their parameters off-line in preparation for the closed-loop experiments. In addition, because of the noise levels present in the sensor data, we designed low-pass filters to smooth out the speed signal and the brake/fuel command signal.