12 research outputs found

    Advanced Braking Methods for Longitudinal Control of Commercial Heavy Vehicles

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    In this report, we develop nonlinear dynamical models and longitudinal control algorithms that coordinate variable compression brake mechanism with service brakes for a Class-8 commercial heavy vehicle. For the coordination and full use of these retarding actuators, we model the multivariable system based on physics-based principles and experimental data. We show that, for one specific critical braking maneuver, the coordination of compression and service brakes reduces the use of the service brakes by a factor of 45, and that it reduces the settling time by a factor of 2. Key words: Advanced Vehicle Control Systems, Brakes, Commercial Vehicle Operations. Speed Control, Vehicle DynamicsTrucks--California--Brakes--Mathematical models, Advanced vehicle control systems

    Identification and Integration of Commercial Heavy Vehicle Retarders

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    This report describes the development and experimental validation of a coordination scheme between friction and discretely variable compression brakes for a Class 8 Freightliner truck used as a development platform in the California PATH program. The coordination scheme that we developed maintains the speed tracking performance of the nominal PID controller which was originally designed by the UCLA team for the case of friction brakes only.....Advanced Vehicle Control Systems, Speed control, Brakes, Vehicle Dynamics, Commercial Vehicle Operations

    Parameter Estimation and Supervisory Techniques for Robust Longitudinal Control of Heavy Vehicles

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    This report describes the development and experimental validation of a coordination scheme between friction and discretely variable compression brakes for a Class 8 Freightliner truck used as a development platform in the California PATH program. The coordination scheme that we developed maintains the speed tracking performance of the nominal PID controller which was originally designed by the UCLA team for the case of friction brakes only. Through the coordination scheme, the command of the nominal PID controller is split into a friction brake command and compression brake command. The integration of the compression brake into the speed control framework reduces the usage and wear of the conventional friction brakes. This report describes the experimental hardware and software setup; open-loop experiments that were conducted to identify the models for the friction brake and the compression brake; the identification procedure of the friction brake and compression brake characteristics and the identification results; the development of the coordination scheme for the friction and compression brakes and the results of closed loop experiments that were used to validate the coordination scheme performance.
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