The Influence Of Control System Signal Computation Period Exerts On Shift Quality Of DCT

In the study of DCT,the shift quality has always been a hot research topic.At present,most optimized shift quality control strategy is based on the continuous control model.In engineering practice,the control strategy running in Transmission Control Unit?TCU?,the TCU can only process digital signal,TCU periodically get sensor signals and calculate and output signals,the interval between two signal input and calculation is called signal computation periodT_cal,T_cal will produce difference between the control of TCU output quantity and amount of control based on continuous model,so the shift of DCT deviating from the expected quality.In addition,smallerT_cal will make the TCU output control quantity closer to the amount of control based on continuous model,and makes the DCT shift quality is close to expectations.But it will increase the hardware requirements of the control system,thus increasing the DCT cost,on the contrary,biggerT_calal will make the DCT shift quality is deviate to expectations,thus decreasing the DCT cost.So during DCT control system design,the selection of hardware needs theoretical guidance.The influence of control system signal computation period exerts to DCT shift quality is studied in this paper.First,set up the DCT inertial phase shifting dynamics model of the object.Then,design the clutch torque control strategy and discretize the closed loop control system by zero-order holder,and DCT inertial phase shifting clutch torque closed loop control system are simulated by simulink.Download the control strategy to dspace rapid control prototyping,and download control object model to real-time computer,then test them in the ring.Results show that increase T_consume can make the closed-loop control system become unstable.Under the same control strategy,increaseT_cal,the amplitude of DCT shift jerk will increase.The influence of T_cal exerts to shift friction loss is very small.The results of this paper have guiding significance for control system hardware selection.