Bei Shaoyi

On Fuzzy-PID Integrated Control of Automotive Electric Power Steering and Semi-Active Suspension

In order to enhance the steering portability, the handling stability, the ride comfort and the safety of the car, the full-car model of the integrated control system of electric power steering (EPS) system and semi-active suspension (SAS) was established, and the fuzzy-PID controller by the fuzzy rule control combined with PID control technology was designed. The simulations were performed and the results are shown that the integrated system can improve the dynamic performance, keep the good car-body attitude and enhance the ride comfort.

Vehicle Sideslip Angle Estimation Based on General Regression Neural Network

Aiming at the accuracy of estimation of vehicle’s mass center sideslip angle, an estimation method of slip angle based on general regression neural network (GRNN) and driver-vehicle closed-loop system has been proposed: regarding vehicle’s sideslip angle as time series mapping of yaw speed and lateral acceleration; using homogeneous design project to optimize the training samples; building the mapping relationship among sideslip angle, yaw speed, and lateral acceleration; at the same time, using experimental method to measure vehicle’s sideslip angle to verify validity of this method. Estimation results of neural network and real vehicle experiment show the same changing tendency. The mean of error is within 10% of test result’s amplitude. Results show GRNN can estimate vehicle’s sideslip angle correctly. It can offer a reference to the application of vehicle’s stability control system on vehicle’s state estimation.

Research on Wheelbase Preview Control for Vehicle Semi-active Suspension Based on Neural Networks

Based on the model of the 1/2 vehicle semi-active suspension with wheelbase preview, combined with neural networks algorithm and PID control theory, a neuron adaptive PID control algorithm was put forward, and designed the single neuron PID controller of semi-active suspension based on wheelbase preview. The simulation calculation was done at different speed, the simulation results showed that, compared with the passive system, the semi-active suspension wheelbase preview neurons PID controlled system can effectively reduce vehicle vibration, compared with the neuron adaptive PID controlled system, the rear vertical acceleration and pitch angular acceleration decreased significantly at the lower speed, improved the ride of the automobile.

Control Optimization of Range Extender’s Start-Stop Moment for Extended-Range Electric Vehicle

Range extender is the core component of E-REV, its start-stop control determines the operation modes of vehicle. This paper based on a certain type of E-REV, optimized the control strategy for range extender start-stop with different driving cycle conditions and target mileage, and conducted the modeling and co-simulation of E-REV with Advisor and Simulink software. The simulation results with chosen driving cycle conditions indicated that certain target mileage, by correcting the battery SOC of range extender start-stop moment can reduce the running time of the range extender, reached the purpose of meeting the vehicle mileage and reducing consumption and emission at the same time.

Design of Multi-mode Switching Damping Shock Absorber for Active Suspension and Ride Comfort Test

In order to enhance the damping adjustable working mode and the adjustment range, a new multi-mode switching adjustable shock absorber was designed based on a traditional hydraulic damper shock absorber. The structure characteristics and working principle were analyzed. The adjustable damper was controlled in the soft compression and soft rebound mode, the hard compression and soft rebound mode, the soft compression and hard rebound mode and the hard compression and hard rebound mode. The strut assembly and electromagnetic valve assembly was designed. The ride comfort test of full vehicle under random input and pulse input were conducted respectively. The results shown that the structure design scheme of multi-mode switching adjustable shock absorber was feasible, and the mean square root value of the weighted acceleration of the driver’s seat had a significant increase trend with the increase of the speed. The root mean square value of weighted acceleration increased with the increase of damping value under random road input. The adjustment range and comprehensive properties of multi-mode switching adjustable shock absorber for active suspension system are improved. It has important theory value and engineering application prospect for active suspension system and its control strategy.

Minimum Time Approach to Emergency Collision Avoidance by Vehicle Handling Inverse Dynamics

Vehicle driving safety is the urgent key problem to be solved of automobile independent development while encountering emergency collision avoidance with high speed. And it is also the premise and one of the necessary conditions of vehicle active safety. A new technique of vehicle handling inverse dynamics which can evaluate the emergency collision avoidance performance is proposed. Based on optimal control theory, the steering angle input and the traction/brake force imposed by driver are the control variables; the minimum time required to complete the fitting biker line change is the control object. By using the improved direct multiple shooting method, the optimal control problem is converted into a nonlinear programming problem that is then solved by means of the sequential quadratic programming. The simulation results show that the proposed method can solve the vehicle minimum time maneuver problem, and can compare the maneuverability of two different vehicles that complete fitting biker line change with the minimum time and the correctness of the model is verified through real vehicle test.