Optimal Servo Design for Lock-Up Slip Control for Torque Converter—Nonlinear Output Regulation Approach

Optimal parameters design method for power reflux hydro-mechanical transmission system

“…The equivalent efficiency h sys of the PRHTS (as shown in equation (20)) and the starting speed ratio i 0 of the TC (as shown in equation (13)) are defined to evaluate the efficiency. The higher the h sys , the more efficient the PRHTS, and the larger the i 0 , the more efficient the TC.…”

“…The use of multi-turbine TC 11 and adjustable TC 12 can enlarge the range of high efficiency. The lock-up TC, 13,14 in which a lock-up clutch would be engaged at a certain speed ratio of the TC to connect the pump impeller and the turbine, can also improve the efficiency dramatically. As for the new structure of hydro-mechanical transmission, the hydro-mechanical power split transmission which can combine the hydrodynamic drive and mechanical drive together was carried out to improve the efficiency of hydro-mechanical transmission, and further research works on improving the efficiency of hydro-mechanical transmission have been based on this specific structure, such as the match between the engine and the transmission 15 and the design of the shifting schedule.…”

Slip control during inertia phase of clutch-to-clutch shift using model-free self-tuning proportional-integral-derivative control

“…During the inertia phase, the clutches A and B are in a slip state. The equations of motion of the engine shaft and the clutch output shaft are expressed by equation (1). The shift is realized by generating engine and clutch torque.…”

“…To reduce transmission shock, the engine angular acceleration must be reduced during the synchronization between the engine and the clutch output shaft rotational speed (i.e. when the differential rotation speed between the engine and clutch output shaft 1 Division of Human Mechanical Systems and Design, Hokkaido University, Sapporo, Japan 2 6th Research Department, ISUZU Advanced Engineering Center, Ltd., Fujisawa-shi, Japan becomes zero). However, to reduce the contact shock, if the shift time is simply lengthened, as shown in Figure 1 (dotted line), slow feeling shift occurs, which leads to discomfort to the driver and a decrease in clutch life.…”

“…In conventional shift control, the shift shock is absorbed by the fluid of the torque converter without lock-up, but in recent years, slip control law of the torque converter using the lock-up clutch has been studied to achieve both improvements in fuel efficiency and reduction in shift shock. [1][2][3][4][5] To realize slip control of the torque converter by implementing a lock-up mechanism, in addition to the multiplication of the lock-up clutch, changing the piston chamber and damper, and adding a proportional valve, a new configuration of the control system is required, which increases cost. Moreover, some vehicles are not equipped with a torque converter.…”