Development Of Clutch Control System In AMT Vehicle

AMT (Automated Mechanical Transmission) is the improvement on the basis of the dry clutch and the manual fixed-shaft. It can implement automatic transmission just as Automated Transmission can do,and it holds the merits of the conventional manual transmission that has high efficiency,low cost,simple structure and being made easily. It is the mechanical-electrical product of high and new technology that is suitable for the situation of our country.Clutch control plays an important role in AMT system,which has relation of ran status and gearshift quality of automobile. Firstly,this paper deals with mathematical model of clutch system. The aim of clutch control is to lessen the starting jerk and the friction work in clutch engaging process through analyzing this two evaluating indicators. Secondly,clutch engaging displacement and speed are taken as the controlled parameters and the engaging method of"fast—slow—fast"is concluded. These lie the foundation for the design of clutch control system.This paper discusses the design of hardware and the programming of software for clutch control system with 80C196 as microprocessor. The PCB board is designed and the electronic control unit (ECU) is developed. The hardware system consists of power circuit,rotation rate measuring circuit,gear position measuring circuit,LCD display drive circuit,H-Bridge drive circuit,which act as the hardware platform of clutch control system incorporation with 80C196. The vehicle speed and engine rotation rate measuring program are designed through M/T method and the issue of low frequency signal rotation rate measurement is solved by HSI module and counter of singlechip. The noise is suppressed with the measurement data processed by digital filtering technique. The clutch engaging displacement and velocity is accurately controlled through digital PID control for motor. The determination program of clutch engagement starting point makes the clutch control self-adapting. The clutch control program for starting process is programmed based on the clutch control rule. This paper deals with in detail the principle and flow of the fore-mentioned content,which is the main portion of software system. The control system reaches the level of excellent driver through installation,debugging and the test in refit car.