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Development of a Toroidal CVT Controller for Agricultural Tractor (II) - PID controller -

트랙터용 토로이달 무단변속기 제어시스템 개발(II) - PID 콘트롤러 개발 -

  • Published : 2004.10.01

Abstract

There are several different types of continuously variable transmission(CVT) such as toroidal drive, belt drive, hydrostatic drive, hydro-mechanical drive. The toroidal CVT is an alternative to the manual transmission, HST, power-shift gear trans-missions or other CVTs. The driver of the CVT tractor doesn't have to operate a shia lever since the CVT controller automatically controls the speed of tractor. Thus, it is much easier to operate the CVT tractor. The fuel efficiency of CVT tractor can be increased since the controller responds quickly to the change in external load on the wheel during field operation. This study was conducted to develop the hardwares and softwares for the toroidal CVT controller which control the variator and the range clutches. The hardware consisted of a measurement system, hydraulic system and computer. And the PID controller was developed using the simulation model of the CVT control system. Through the simulation, the control coefficients for the PID controller were selected. Finally, the performance of the CVT control system was evaluated by step response test and torque response test. The settling time of the CVT control system appeared to be fast enough for field operations.

Keywords

Tractor;Transmission;CVT;Simulation;PID;Control System

References

  1. Merritt, H. E. 1967, Hydraulic control systems, John Wiley & Sons, Inc.
  2. Yoo, S. N. 1989. Electronic-hydraulic Hitch Control System for Agricultural Tractor. Seoul National University, Ph.D. Thesis
  3. Wicke, V., C. J. Brace and N. D. Vaughan. 1996. The potential for simulation of driveability of CVT vehicles. SAE paper 00PC-218
  4. Kim, H. J. and K. H. Ryu. 2004. Development of a Toroidal CVT Controller for Agricultural Tractor (I) - Simulation for control system - J. of the KSAM 29(4).(ln Korean)
  5. Sung, D. H. and H. S. Kim. 1994. Shifting Algorithm and Response Characteristics of CVT, Transactions of the KSAE, 2(6):9-17.(In Korean)
  6. Patterson, M. 1996. The full-toroidal variator in theory and in practice. SAE paper 9636394
  7. Choi, D. H. and H. S. Kim. 2002. Control Strategy of Ratio Changing System for a Metal V-Belt CVT Adopting Primary Pressure Regulation, Transactions of the KSAE, 10(3):201-208.(In Korean)
  8. James I. B. and N. D. Vaughan. 1996, Design and component matching of a pressure control circuit. SAE paper 961854
  9. Brockbank, C. and H. Heumann. 2002. Delivery of IVT for a 5 litre SUV : Addressing the concerns of Geared Neutral, Innovative Fahrzeug Getriebe C1143 20-21 March 2002
  10. Funatsu, K., H. Koyama and T. Aoki. 1996. Electronic Control System of Honda for CVT. Proceedings of the International Conference on Continuously Variable Transmissions, Yokohama, Japan