Development of Cooperative Controller for Dual-Motor Independent Drive Electric Tractor

This paper proposes a control strategy of dual-motor independent drive electric tractor with cooperative control power take-off (PTO) and driving systems by investigating its structural characteristics to meet the field operation requirements. In the following operation mode, the vehicle speed is taken as the input signal, and the PTO motor speed is followed by the vehicle speed at a proportional ratio. Four different principles of collaborative control strategy-based stability control, namely, general closed-loop, conventional PID, adaptive fuzzy PID, and fuzzy neural network adaptive PID controls, are proposed to meet the requirements during speed change. Hardware design is divided into modules in accordance with circuit function. Software design is divided into application layer and underlying software, where the application software realizes the control strategy of the entire machine. The underlying software is based on the hardware driver of MC9S12XEP100 that connects the application layer software and hardware. A hardware-in-the-loop test platform based on dSPACE/DS1007 is built to test the function of the collaborative controller. Results show that the stabilization time of fuzzy neural network adaptive PID control is 0.024 s. Compared with the three other control modes, the settling time decreases by 0.256, 0.034, and 0.028, respectively, and the overshoot decreases to 1.6%. Root locus analysis results show that the stability of the system is the best. Under the entire machine cooperative operation mode hardware in the loop test, the PTO motor maintains the fixed target speed under the fixed speed output mode, and the PTO speed in the following mode has a good follow-up to the vehicle speed. The controller realizes the control of the power output shaft to cut between the following and standard speeds. It also meets the requirement of cooperative control in the operation of dual-motor independent drive electric tractor.