Study on Traction Control System for Four Wheel Drive Vehicle Based on Inter-axle Torque Distribution
|Keywords||Four Wheel Drive Vehicle Traction Control System Axis Torque Distribution Control Strategy Simulation|
During accelerating on the weak adhesive roads, the driven-wheels of vehicle are tending to over-spin, which leads to the adhesive force between the tires and road decrease, hence the performance of the acceleration and stability is influenced disadvantageously. Traction control system can make use of the road adhesion effectively and distribution of traction torque reasonably through controlling the slippage state of wheels, and the performances of traction and stability of vehicle are improved.This paper are studied by four wheel driving vehicle, the traction control system is particularly studied in this paper. The mainly research work carried on the following:①To Analysis of the torque distribution characteristics and differential characteristics of the planetary wheel inter-axle differential, Axis variable torque distribution program is put forward by clutch limit sliding planetary wheel inter-axle differential; Axis variable torque distribution relationship is derived; Analysis of the working principle for the axis torque distribution; The initial shaft torque distribution ratio is identified.②The main structure for four wheel drive vehicle simulation model is confirmed, and vehicle dynamic mathematical models are established, This models provided the foundations for building of the off-line simulation platform.③To research the vehicle traction control targets under the different driving conditions, strategies are identified. On this basis total program of traction control is developed, and engine throttle control system、inter-axle torque distribution control system and driven wheel brake control system are designed by using PI control method and Fuzzy control method.④Based on four wheel drive vehicle model and traction control system control algorithms, Traction control system for four wheel drive vehicle off-line simulation platform are carried up by Matlab/Simulink, Off-line simulation for four wheel drive vehicle traction control system is Conducted, The simulation results indicate: Traction control strategies can prevent excess spin of driven wheel effectively, so as to make use of the road adhesion effectively and improve performances of dynamic, Shift security and stability of a vehicle.