Stabilizing Control of Speed Synchronization for Integrated Motor-Transmission Powertrains over CAN Through Co-Design Approach

Clutchless integrated motor-transmission (IMT) powertrains with large speed radio interval (LSRI) have considerable advantages for electric vehicles (EVs). However, the absence of the clutch and the LSRI would make the speed synchronization control design a challenging problem. Furthermore, the connections between the controllers and the actuators in modern EVs are usually realized via a controller area network (CAN), which would induce not only network-induced delays but also limitations of packet capability and bandwidth. This paper aims to present a co-design approach which can deal with all these challenges and limitations and still yield the high-quality speed synchronization. Firstly, a continuous-time dynamics model of a clutchless IMT powertrain for an EV is presented and the speed synchronization control is explained. Then, a network-induced delay model considering the limitations of packet capability and bandwidth is derived, and the discrete-time models of the closed-loop system with bounded delay pieces are constructed. Thirdly, a co-design approach is proposed, which is based on Lyapunov stability criterion and offline priority scheduling. The results of simulations show the proposed approach can obviously reduce the network-induced delays and ensure the stability of the speed synchronization control.