Design And Control Of Direct Drive Clutch Hydraulic Actuator

Automatic transmissions for vehicles are mainly classified into Automatic Transmission,Continuously Variable Transmission,Double Clutch Transmission and Automated Mechanical Transmission.AMT has the advantages of high efficiency,simple structure,and low cost compared to other kinds of automatic transmissions.However AMT has the problems in power interruption and launch control,so it is not comfortable.Many studies focus on the automatic clutch system of AMT to improve the launch and shift performance of AMT vehicles.As a key part of the automatic transmission,the automatic clutch system plays an important role in the performance of the vehicle.The performance of the automatic clutch is mainly determined by the structure and the control algorithm.Therefore,based on automated mechanical transmission,a new clutch hydraulic actuator and controller are designed.In the hydraulic actuator,the DC motor drives the gear pump to achieve the change of flow in the hydraulic system through the change of the motor speed.It is directly connected to the hydraulic release bearing to realize the displacement control of the clutch.Because the structure has no high-speed solenoid valve to control the flow,it has simple structure,low price,and it is convenient for popularization and application.In this paper,the performance of direct drive clutch hydraulic actuator is studied and analyzed through structural design,modeling and simulation,bench design and vehicle test.The main contents are as follows:1.The characteristics and working principle of four kinds of automatic transmissions are introduced.The research status of clutch actuators is summarized,and the characteristics of different types of actuators are analyzed.2.Clutch actuator structure is designed.After introducing the background,the design requirements of the clutch actuator are proposed.After analyzing the characteristics of the existing actuators,this paper proposes a novel structure based on the hydraulic actuator.The DC motor with external gear pump is used to control the flow in the way of controlling of the rotation speed,and then the clutch displacement control is realized.Based on clutch diaphragm spring load characteristics,hydraulic characteristics,and other characteristics,the mechanical components that make up the system are selected.3.Simulation analysis is completed.Mathematical model of each component in the system is given,and a feedforward feedback gain-scheduling PID controller is applied.The system is modeled in AMESim,and simulation results under different conditions are analyzed through AMESim-Matlab/Simulink co-simulation.4.Bench test and vehicle test is completed.The working principle of the motor driver and the composition of the bench are introduced.Based on dSPACE-MicroAutoBox the experimental bench of the clutch actuator is established.The response time and the steady-state error of the clutch of different working conditions in the bench experiment are analyzed.The results are compared with the simulation results.The clutch actuator is applied to the I-AMT.The vehicle test is carried on a mini-EV.The bench test and vehicle test verify that the performance of the algorithm and mechanism can meet the design requirements.