System level control of a hybrid-electric vehicle drivetrain

The drivetrain model of a hybrid-electric vehicle is controlled and simulated from a system level approach. These system level control strategies depend upon accurate transient and steady-state vehicle information from detailed models. The drivetrain includes an internal combustion engine, transmission, vehicle chassis/body, induction motors and inverters, and lead-acid batteries. The system level design and control technique is a comprehensive methodology for control system and vehicle configuration development that begins from vehicle requirements. First, a supervisory control structure is proposed to manage the components and low-level controllers. Next, the inverse dynamics of the vehicle are used to size critical drivetrain components based on the requirements the vehicle must meet. Control laws are presented that improve component and system level performance. Electric motor command following is improved through output feedback control and utilization of known disturbances in feedforward. A nonlinear, adaptive identifier of vehicle chassis/body parameters is implemented in simulation for use by the supervisory controller.