Testing the Regenerative Brake System of an Electric Vehicle

The Task

Developing and testing the torque management for the regenerative brake system of an electric vehicle.

The Challenge

Simulating an electric-drive vehicle, energy storage system, and serial regenerative brake system that consists of a hydraulic brake and an electric motor that works as a brake actuator. Both systems must convert the braking torque requested by the driver and reproduce a cross-fade between electric regenerative and hydraulic braking. The driver’s desired brake force is captured by a brake pedal that is connected via x-by-wire.

The Solution

ASM offers a complete simulation model for an electric vehicle with an energy storage system, an electric drive for the front axle and one for the rear axle, as well as a serial regenerative brake system. The management for requesting the drive and braking torque (electric generator and hydraulics) is also simulated or can be substituted by the torque requests of real ECUs at the HIL simulator. Therefore, the distribution of the driver’s desired torque to the regenerative and hydraulic brake system can be analyzed. Furthermore, the model supports research into the distribution of the drive torque to the two electric motors of the front and rear axle. Because longitudinal and vertical dynamics of the electric vehicle can be simulated in detail, the model can also be used to analyze the vehicle dynamics properties.