Abstract
Keywords Dynamic Simulation, Hydrodynamic Torque Converter, Torque Converter Clutch, Clutch Slip System, Sliding Mode Control
Abstract Since the introduction of the torque converter clutches (TCC) in the 1970s, the trade-off between the drivability and the fuel efficiency of the vehicle has been greatly reduced. With a well-tuned torque converter lock-up control strategy and appropriate hardware components, tremendous improvements in performance and significant fuel savings can be realized. With the developed hydrodynamic torque converter model [7], the control strategy of minimal slip-type torque converter clutch is to be introduced by well known nonlinear control theory sliding mode control.
The objective of slip control is to reduce transmission of the torque variation generated by the engine, and to realize low fuel consumption by extension of operation of the clutch to lower engine speeds. Clutch slip control systems maintain a specified low nonzero slip in the torque converter so that engine noise and vibration are not transmitted to the drive train.
For controls, the application of the well known nonlinear control theory which is sliding mode control is to be investigated due to its invariance property and the ease of use by order reduction as well as its robustness. It is expected that the sliding mode control design not only provides tracking performance, but it also ensures the robustness against uncertainties such as unmodeled dynamics and disturbances. The nonlinear model along with a nonlinear controller may help use less expensive and less precise valves in active vehicle problems such as vibration isolation, where the valve cost is a major deterrent for commercial applications. Although model-based control techniques will benefit from the use of our detailed models of system dynamics, improved performance requires a priori knowledge of system configuration and properties. On the other hand, robust control techniques such as sliding mode control are less sensitive to considerable variations in system properties, and may provide better performance for a wider range of system configurations [10].
The configuration of modelling and integrating of TCC has some practical implications in view of the current emphasis on development of similar hardware with the aim of improved performance, fuel economy, and driving comfort. The hydrodynamic torque converter model is good for studying the behaviour of the transient effect of power train system in high frequency range as well as torque converter clutch control in all senses. We have developed a nonlinear control oriented model. The system model is fully implemented in Matlab/Simulink ® simulation package. In its final form, this research will likely provide new tools to analyze and improve the performance of the torque converter clutch slip control system. Possible applications of this research include the use of cheaper nonlinear model with a nonlinear controller in an automotive industry.