Study On Intelligent Control Of Commercial Vehicle AMT

The main type of transmission of domestic commercial vehicle is fixed shaft transmission. Electronic control unit (ECU) added in the structure of the existing transmission was used to control the implementation of the shift operating mechanism, which could improve fuel economy and comfort.It was difficult to control clutch engagement and shift for the varid load, road condition and driver's intention, which affected the vehicle maneuverability. Currently controlled effect to control clutch engagement and shift was not achieve the desired result for some infection factor were not considered, which restricted the further improve the performance of power, economy and comfort. For the above analysis, the paper made the following work,(1) Research, application status and development trend about AMT was analyzed and introduced. The dynamic model was established through theoretical analysis and system modeling. Analysis of the characteristics of intelligent control systems and fuzzy control system was proposed for the specialty of AMT. Analysis of the gas flow characteristics and pneumatic clutch controlled mechanism. Multi-position cylinder block was used to control selection route and shift route to improve shifting performance and institutional reliability.(2) Engagement of clutch and evaluation indicators was introduced and analyzed. The factor to influence clutch engagement was analyzed. Considered the influence of road condition and vehicle load to engagement of clutch, quality of vehicle conversion factor was proposed and used to control speed of clutch engagement in control layer. The fuzzy PID control method was used to control fluctuation of engagement on the objective position and prevent overshoot occur, which achieved control to the implementation of the clutch engagement.(3) Opening fast-changing of throttle influenced vehicle shift and resulted in frequent shift. For the vehicle inertia was large, the change of vehicle speed was lagged the change of throttle. Used fuzzy control method, frequent shift was eliminated to influence of the opening fast-changing of throttle.(4) Considering varied road and driver's intention, the shift curve was amend to content varied condition.(5) Change shift control communication was used to CAN protocol. Entire control unit works in a safe and reliable rang, considering the influence of the supply voltage to operator implementation component, which was not too high or too low.The innovation of this paper was,1, Quality of vehicle conversion coefficient had been put forward and used to control clutch engagement. Quality of vehicle conversion coefficient reflected information of road condition and vehicle load, which could fully consider the impact of external factors to clutch engagement. These factors was considered could control clutch engagement to accord with intention of driver.2, A simple electronically controlled pneumatic gear change implementing agencies was adopted to control shift route. This agency using the multi-position cylinder block controllers'accurate stroke reduced the impact and improves shift performance and reliability of body.3, In order to prevent fluctuation in the target locations of clutch engagement which caused the big impact of clutch plate and affect the life of clutch, fuzzy PID controller was put forward, which could improve performance of clutch engagement which had delay and uncertainty model structure. This method had intelligent functions but also had a set structure. The fuzzy PID controller had the rapid respond and small overshoot.4, Rate of change in throttle opening and ramp information were two of input parameters of fuzzy controller to amend shift curve. The value was between the best power and economy curve value. The value met practice shift actrequirement.5, In circumstances of opening the throttle rapidly changing, the larger vehicle inertia force caused that the vehicle speed's change lagged the throttle's change. That this result did not take full account of the factors to shift in ECU controller resulted in frequent shift. That the rate of rapid changed in throttle opening was a complement parameter based on the original control input parameters was put forward to solve this question.6, For the power control part, it was considered that not only overvoltage of power impacted to electronic components but also undervoltage influenced to the implementation of components. This method ensured of the entire control circuit in a safe and reliable work area. Changed shift control communication was used to CAN protocol.