The application of lock-up clutch in hydraulic torque converter means an essential improvement of transmission technology to vehicle. Based on engine and torque converter characteristics, this article introduces a method to get a locking-up. control algorithm of hydraulic torque converter through MATLAB programming. The analysis of locking-up process is presented at first, following the establishment of locking-up and unfastening algorithm. Moreover, on the basis of MATLAB/SIMULINK, according to the math-model, a simulated modeling of the locking-up algorithm is made. The vehicle system integration model consists of engine, hydraulic torque converter with lock-up clutch, gearbox, gear-shift algorithm with its control system, and vehicle body dynamic system. Finally, the focus is in particular on the dynamic performances of the simulated model to analyze how the vehicle operates under the locking-up algorithm. The calculated and simulated result indicates that the simulation model can predict the locking-up performance of the target vehicle successfully.
