Zhu Tianjun

Research on Road Friction Coefficient Estimation Algorithm Based on Extended Kalman Filter

High quality estimation of road/tire friction coefficient has important role in vehicle control system like anti-lock braking system (ABS), traction control system etc. For this purpose the paper researches on the road/tire friction coefficient estimation algorithm based on the extended Kalman filter theory. At the same time, a simulation verification of the road/tire coefficient estimation has been made using the software CarSim7.0. The result shows that the EKF estimation accuracy of road/tire friction coefficient is satisfied very well. It provides a new method for the vehicle road/tire friction coefficient estimation.

Vehicle State Estimation Based on Unscented Kalman State Estimation

This paper presents a method of estimating vehicle states using an Unscented Kalman filter (UKF). The UKF developed estimates Vehicle motion, such as yaw rate and side slip angle, from the noisy measurement set. The vehicle state estimation using a non-linear vehicle model with Unitire tire model will be compared to the measured state which is subjected to the same tests, in order to validate the estimated state. In this paper we also discuss the estimation algorithm of UKF. The accuracy of the estimator will be tested. The ultimate aim of this work is to provide a new way of vehicle state estimation to a controller such as ESP or VDC. The result is shown that this application of the UKF is effective in estimation of vehicle state under ISO slalom and ISO double lane change conditions.

Advanced Integrated Control Strategy Based on SBW and 4WS

This paper proposes a chassis integrated control system theoretically utilizing SBW system by using 4WS method to improve vehicle handling and stability. With the application of integrated SBW and 4WS strategy, this paper investigates the effectiveness of the proposed control system in enhancing vehicle handling and stability. Based on the 7 DOF vehicle dynamic models, the paper have proposed integrated control strategy for SBW and 4 WS including forward and feedback control methods in the four wheels (4WS). Two control methods are compared by simulation results and driver simulator test results. The simulation results indicated that 4WS for SBW can effectively improve the vehicle handling.

Improving Vehicle Stability Using Electro-hydraulic Braking System

Vehicle stability control for the vehicle is investigated using electro-hydraulic brake (EHB) control in this paper. It describes a vehicle stability controller based on Electro-Hydraulic Braking (EHB) System which acts on the brake system to generate a corrective yaw moment that helps the vehicle to follow the course desired by the driver. A cosimulation system for EHB has been developed in this research. The performance of the vehicle stability control algorithm is evaluated using Carsim, AMEsim and Matlab co-simulation. The co-simulation results are shown that the vehicle stability controller based on EHB is very effective for enhancing the vehicle stability for various emergency driving situations.

Research on Heavy Truck Rollover Prevention Based on LMI Robust Controller

This paper sets up a vehicle dynamic model which is used to determine rollover risk of heavy truck under various driving conditions. Using this real-time dynamic model, it proposes a new measure of performance for vehicle rollover prevention, the Load Transfer Ratio (LTR), and design the differential braking controller based on LMI robust control to prevent rollover occur. The paper also obtains the controller which can adopt the robustness to variations in vehicle speed. The simulation results show that the LMI controller is very effective in vehicle rollover prevention control.

Rollover prevention for heavy trucks using robust control

Heavy truck rollovers are dangerous and possibly fatal accidents. This paper discusses a robust control algorithm to improve the roll stability of heavy trucks. The controller minimizes the lateral load transfer (LTR) to reduce the rollover probability using differential braking. The paper also designs the robust controller which can adopt the robustness to variations in vehicle speed. The simulation results show that the robust controller is very effective in vehicle rollover prevention control of heavy trucks.

A Real-Time Rollover Warning System for Heavy Duty Vehicle

This paper proposes a real-time rollover threat warning system (RWS) of heavy duty vehicle. The function of RWS is used to determine the rollover threat of heavy duty vehicle and warn the driver to adjust the operation during dangerous conditions. The paper suggests a new algorithm of rollover warning for heavy duty vehicle based on accurate PTR metric. The effectiveness of the RWS is validated by test data of heavy duty. The vehicle test results show that the RWS system is very suitable for application in rollover risk assessment and warning.

The design of rollover prevention system in heavy vehicles based on an robust method

This paper presents a novel approach for designing robust vehicle rollover prevention controllers. The control methodology is based on guaranteeing a set of linear matrix inequality (LMI) conditions, which results in controllers that are robust stable. An active braking control is used to decrease the rollover risk of heavy vehicles. The paper also obtains the controller which can adopt the robustness to variations in vehicle speed. The simulation results show that the LMI controller is very effective in vehicle rollover prevention control.

Modelling and Active Safe Control of Heavy Tractor Semi-Trailer

The active safety and stability of tractor semi-trailer have becoming big concern among the road transportation industry. The paper sets up a six-axle plane dynamic model for simulating the yaw/roll stability of heavy tractor semi-trailer using Matlab/Simulink. LQR controller is chosen to produce the optimum compensate yaw moment to correct the vehicle path based on the bias of yaw rate and lateral acceleration respective. The allocation strategy of braking moment can allocate the braking moment to unique wheel at particular moment, which is the differential braking. At the same time, PD controller can regulate the longitudinal slip ratio of tires to make it work at optimum slip ratio nearby to obtain maximum brake force. The simulation results show that yaw-roll stability of tractor semi-trailer has improved effectively after applying the differential braking.

Development of MRF Damper Modelling and Validation of MRF Damper Test

Active/semi-active suspension systems are getting widely accepted for their potential to improve ride comfort of passenger cars. In this work, the paper develops the model of magnetorheological fluid (MRF) damper to describe the hysteretic behaviors and damper characteristic. It used the modeling-after-test method to establish an accurate MRF-damper model, and the MRF damper model is consecutive adjustable. The linear interpolation technique is used to derive an equivalent MRF damper model. The simulation results of the developed MRF model are verified using MTS damper test. It is shown that the built MRF model matches the test data very well.