No abstract

The existing electrically automated manual transmission employs DC motors to carry out gearshift events. It is relatively complicated and has potential to be improved both in structure and transmission efficiency. A novel gearshift system that utilizes a 2-DOF electromagnetic actuator to realize the automation of gearshift is proposed. The structure and working principle are introduced, and the coupling system model of the actuator is developed to investigate its characteristics. The results show that the utilization of the electromagnetic actuator in automated manual transmission gearshift system is appropriate. Multi-stage control strategy including PID algorithm and optimal control is introduced to improve the gearshift quality. A look-up table is developed to adjust the peak force of synchronization process according to the working condition. Finally, the conceptual gearshift system and the control strategy are verified on a test bench. The results show that the controller can adjust the peak force of the synchronization process timely and the designed control strategy achieves the compromise of indexes of gearshift quality. The novel gearshift system is technically feasible.

No abstract

Electric automated manual transmission usually adopts direct current motors and intermediate gearings to accomplish gear change. The structure can be simplified further to achieve better dynamic response and mechanical efficiency. A new type of gearshift system which adopts two electromagnetic linear actuators is presented. The intermediate gearings including motion converters are canceled, and the electromagnetic linear actuators drive the shift fork directly to move the synchronizer to engage different gears. The novel gearshift system is described in detail, including the connection, working principle, and performance. Specific working phases of the synchronization are introduced and mathematical equations of each phase are provided. After the specific feature analysis of each phase, the performance effect factors are deduced and the corresponding control requirements are proposed. Considering the stability of the performance, the robust control method, namely, active disturbance rejection control, is adopted. The time optimal method is introduced to optimize the dynamic response of the active disturbance rejection control method to achieve a shorter gearshift time. Comparative simulations among the active disturbance rejection control, time optimal-active disturbance rejection control, and proportional-integral-derivative methods show the distinct improvements of the novel gearshift system combined with the time optimal-active disturbance rejection control method. Finally, gearshift experiments are implemented. The results demonstrated the availability of the novel gearshift system and the designed control strategy.