Study On Shift Controlling Of Uninterrupted Shift Transmission

UST-Uninterrupted Shift Transmission can realize automatic switching of power inshifting process by the reasonable combination between one-way force transfer mode andoverrunning mode of controllable one way overrunning clutch. Based on the previousresearch, the power shift characteristic of UST has been verified through experiment intest-bed. The shift process of UST not only overcomes the inhered torque interrupt drawbackof automated manual transmission (AMT), but also avoids the precise clutch-clutchoverlapping control of both planetary-automatic transmission (AT) and Dual ClutchTransmission (DCT). UST has adopted the parallel shaft-gear structure which is similar toManual Transmission, Due to its advantages of high transmission efficiency, low cost, goodmanufacturing succession, etc., UST has good industry popularizing prospect. At present,UST technology is still in the earlier stage of research, further study is required, especiallyresearch about shift controlling. In the paper, the main research work is as follows:MCS-Multimode Controlled Shifter, which have the characteristics of two-way forcetransfer and overrunning, is transformed from one way overrunning clutch by controllabletransformation. Since the transformation technology of MCS is difficult to implement, USTtechnical scheme use the combination of two modes controlled shifters. In order to reduce thenumber of actuators, based on the shift mechanism of UST, linkage shifting mechanism isdesigned, which not only realized the reliable shifting by mechanical interlock, but alsoreduced the control difficulty of the system.In order to improve shift quality of UST, it is necessary to carry out integrated controlabout engine and clutch to consideration to jerk and friction work. Because of control objecthas the characteristics of multi objectives, time variation and needless of accurate model, if itapply traditional control methods in shifting process, the control process cannot obtainenough accuracy.According to analysis on related methods of domestic and international research, andcontrol strategy of UST shifting process depends on experiences and experiment data, sofuzzy algorithm is utilized to design control strategy of shifting. Based on the rapid modeling approach of simdriveline, dynamic model of automobile include UST is established, then theshifting controller based of fuzzy algorithm is also designed in the model to control thepower of engine and hold-down force of clutch. The result of simulation proves that thismeans of control method is correct and usable.Based on the original transmission test-bed, measurement and control system of test-bedis upgraded, and relay module is designed to improve the sampling precision of torque androtational speed signals, the system can realize data acquisition, data storage and controllingof clutch and motor. The shifting controller of fuzzy algorithm is downloaded to ElectronicControl Unit (ECU) by the technology of Real Time Workshop (RTW). The experimentalresults of shifting control reflect the validity of fuzzy control strategy, the integrated controlexperiments of power source and clutch show that fuzzy control strategy can significantlyimprove shift quality, it means that the control strategy can effectively reduce the frictionwork of clutch, and can decrease shifting impact in some degree.