Research On TCS Strategy For Four-Wheel Drive Vehicle

When an automobile is moving on a rough road with disparate adhesion conditions, certain wheels might slip for lack of adhesive force; in this case, if the wheel slip was poorly controlled, the engine torque would lead to the acceleration of the wheel constantly, which seriously affects the automobile's dynamical performance finally. Even worse, when steering, if the front wheel were to slip and uncontrolled, the automobile could run deviation or even result in the vehicle uncontrollable. In order to achieve optimal power performance and driving safety synchronously, TCS(abbreviation of Traction Control System) become the standard configuration for most four-wheel drive cars.This paper studies TCS strategy for the four-wheel-drive car and proposes a comprehensive strategy, known as the “options”, whose main idea is: according to the road condition, different control strategies are applied to ensure the stability of automobile power and driving performance. The course of the work is just like making a choice before the control process is introduced and then choose the corresponding strategy. Specifically, first of all, establish working condition recognition as a basis for the control strategy selection, and then determine the driving modes,(there are four modes considered in this paper); on different working conditions, the corresponding control strategy(different control target and controller), are selected, which can make vehicles have good performance whatever the road conditions. By means of off-line simulation, the vehicle model is established for the simulation under a given condition and the comparison of simulations is conducted, including the simulations of vehicle with and without the TCS, under various working condition, and the ones that on same conditions, but different targets and controller are considered. The comparison of the results shows that the option strategy has good effects on the stability of the vehicle, providing reference for the TCS strategy research and real vehicle testing.This paper mainly deals with: briefly analysis of the latest development and research focusing on four-wheel drive technology in China and abroad; analysis of TCS control scheme; brief introduction of the research object- torque distribution structure of AWD vehicle. Research on torque distribution characteristic and speed characteristic of planetary gear differential mechanism, which determines the structure plan of the inter-axle differential and differential between the wheels; and also research on the working principle of the motor control friction plate differential. Modeling four-wheel drive vehicle in the vedyna module of TESIS – DYNAware: analyze the judgmental parameters while steering process; determine the neutral steering sensitivity as the target volume of neutral steer. Exploration of the four typical driving conditions by establishing select method of control strategy, and set up control strategy model according to distinct situation; control strategies are formed by different control objectives and actuators, in the end, the vehicle TCS control system are connected with the vehicle model and then offline simulation is conducted. The results of the simulation show that: the control strategies for different driving conditions, adopt corresponding control objectives and methods, and the effect is good.