Estimation of Tire Braking Force and Road Friction Coefficient Between Tire and Road Surface For Wheel Slip Control

2004 ◽  
Vol 28 (5) ◽  
pp. 517-523 ◽  
Keyword(s):  
Friction Coefficient ◽  
Road Surface ◽  
Wheel Slip ◽  
Slip Control ◽  
Road Friction ◽  
Braking Force ◽  
Road Friction Coefficient

scholarly journals Slip Control of Electric Vehicle Based on Tire-Road Friction Coefficient Estimation

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Gaojian Cui ◽  
Jinglei Dou ◽  
Shaosong Li ◽  
Xilu Zhao ◽  
Xiaohui Lu ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Electric Vehicle ◽  
Slip Ratio ◽  
Braking Performance ◽  
Slip Control ◽  
Coefficient Estimation ◽  
Road Friction ◽  
Braking Torque ◽  
Novel Method ◽  
Road Friction Coefficient

The real-time change of tire-road friction coefficient is one of the important factors that influence vehicle safety performance. Besides, the vehicle wheels’ locking up has become an important issue. In order to solve these problems, this paper comes up with a novel slip control of electric vehicle (EV) based on tire-road friction coefficient estimation. First and foremost, a novel method is proposed to estimate the tire-road friction coefficient, and then the reference slip ratio is determined based on the estimation results. Finally, with the reference slip ratio, a slip control based on model predictive control (MPC) is designed to prevent the vehicle wheels from locking up. In this regard, the proposed controller guarantees the optimal braking torque on each wheel by individually controlling the slip ratio of each tire within the stable zone. Theoretical analyses and simulation show that the proposed controller is effective for better braking performance.

scholarly journals Handling Enhancement of Autonomous Emergency Steering for Reduced Road Friction Using Steering and Differential Braking

2021 ◽  
Vol 11 (11) ◽  
pp. 4891
Author(s):  
Yu-Min Lin ◽  
Bo-Chiuan Chen
Keyword(s):  
Friction Coefficient ◽  
Lateral Displacement ◽  
Work Load ◽  
Path Tracking ◽  
Road Surface ◽  
Steering Angle ◽  
Actuator Dynamics ◽  
Single Input Single Output ◽  
Road Friction ◽  
Road Friction Coefficient

Steering has more potential than braking to prevent rear-end collisions at higher relative velocities. A path tracking controller based on multi-input multi-output (MIMO) model predictive control (MPC) is proposed to enhance the handling performance of autonomous emergency steering in this paper. A six-state MIMO bicycle model including actuator dynamics of steering and differential braking is used for model prediction. Two control inputs are front wheel steering angle and direct yaw moment. Two model outputs are lateral displacement and heading angle. According to the work load ratios at four wheels, control allocation is used to determine the optimal braking force distribution to prevent tire force saturation. The performance of a single-input single-output (SISO) MPC that uses only steering angle control to track the lateral displacement of the desired path is employed to benchmark the performance of the proposed algorithm. Simulation results show that both SISO MPC and MIMO MPC can track the path on nominal road surface with high road friction coefficient of 0.9. For a road surface with medium road friction coefficient of 0.7, the SISO MPC is unable to track the path and loses directional stability. However, the MIMO MPC can still track the path and demonstrate robust path tracking and handling enhancement against model uncertainty due to reduced road friction.

Estimation of the Maximum Tire-Road Friction Coefficient

2003 ◽  
Vol 125 (4) ◽  
pp. 607-617 ◽  
Author(s):  
Steffen Mu¨ller ◽  
Michael Uchanski ◽  
Karl Hedrick
Keyword(s):  
Friction Coefficient ◽  
Estimation Algorithm ◽  
Road Surface ◽  
Measurement Noise ◽  
Misclassification Rate ◽  
The Road ◽  
Subtle Effect ◽  
Road Friction ◽  
Friction Estimation ◽  
Road Friction Coefficient

We develop and test a “slip-based” method to estimate the maximum available tire-road friction during braking. The method is based on the hypothesis that the low-slip, low-μ parts of the slip curve used during normal driving can indicate the maximum tire-road friction coefficient, μmax. We find support for this hypothesis in the literature and through experiments. The friction estimation algorithm uses data from short braking maneuvers with peak accelerations of 3.9 m/s2 to classify the road surface as either dry μmax≈1 or lubricated μmax≈0.6. Significant measurement noise makes it difficult to detect the subtle effect being measured, leading to a misclassification rate of 20%.

Anti-Lock Wheel Slip Control With an Adaptive Searching Algorithm for the Optimal Slip

2015 ◽  
Author(s):  
Ning Pan ◽  
Liangyao Yu ◽  
Lei Zhang ◽  
Zhizhong Wang ◽  
Jian Song
Keyword(s):  
Lyapunov Theory ◽  
Modulation Amplitude ◽  
Wheel Slip ◽  
Slip Control ◽  
The Road ◽  
Road Friction ◽  
Speed Fluctuation ◽  
On The Road ◽  
Pressure Modulation ◽  
Abs Algorithm

An adaptive searching algorithm for the optimal slip during ABS wheel slip control is proposed. By taking advantage of the fluctuation of wheel slip control, the direction towards the optimal slip can be found, and the target slip calculated by the algorithm asymptotically converged to the optimal slip, which is proved using the Lyapunov theory. A gain-scheduling wheel slip controller is developed to control the wheel slip to the target slip. Simulations on the uniform road and on the road with changed friction are carried out to verify the effectiveness of the proposed algorithm. Simulation results show that the ABS algorithm using the proposed searching algorithm can make full use of the road friction and adapts to road friction changes. Comparing with the conventional rule-based ABS, the pressure modulation amplitude and wheel speed fluctuation is significantly reduced, improving control performance of ABS.

scholarly journals Study on Pre-Warning Method of the Lateral Security of Heavy Vehicle in Deteriorative Weather

2014 ◽  
Vol 8 (1) ◽  
pp. 292-296
Author(s):  
Zhi-Guo Zhao ◽  
Min Chen ◽  
Nan Chen ◽  
Yong-Bing Zhao ◽  
Xin Chen
Keyword(s):  
Friction Coefficient ◽  
Critical Speed ◽  
Warning System ◽  
Heavy Vehicle ◽  
Heavy Vehicles ◽  
Core Technology ◽  
Road Friction ◽  
Turning Radius ◽  
Safety Features ◽  
Road Friction Coefficient

The lateral security of heavy vehicle in deteriorative weather is one of the main causes of accidents of vehicles on roads. Road safety has become a subject of great concern to institutions of higher education and scientific research institutions. There are important theoretical and practical significances to explore applicable and effective lateral safety warning methods of heavy vehicles. One of the purposes of this paper is to provide a good theoretical basis for the core technology of heavy vehicle safety features for our country's independent research and development. Aiming at the issue of lateral security of heavy vehicle for road conditions in deteriorative weather, this paper constructs the framework of the lateral security pre-warning system of heavy vehicles based on cooperative vehicle infrastructure. Moreover, it establishes vehicle lateral security statics model through analysis of the force of the car in the slope with section bending and states the parameters of vehicles for no rollover. The side slip is indexed to calculate critical speed of vehicles in a bend. This paper also analyzes the influence of road friction coefficient, the road gradient and the turning radius on the lateral security of the vehicle with critical speed on the asphalt pavement with surface conditions ranging from wet, dry, snowing or icy. The calculation results show that the bad weather road conditions, road friction coefficient and turning radius have obvious influence on the lateral security critical speed. Experimental results indicate that the critical speed error warning is within 4% and it meets the design requirements.

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