Stability Regions of Vehicle Lateral Dynamics: Estimation and Analysis

2020 ◽  
Vol 143 (5) ◽  
Author(s):  
Yiwen Huang ◽  
Wei Liang ◽  
Yan Chen
Keyword(s):  
Load Transfer ◽  
Equilibrium Points ◽  
Longitudinal Velocity ◽  
Linearization Method ◽  
Stability Control ◽  
Stable Operation ◽  
Lateral Stability ◽  
Ground Vehicles ◽  
Stability Regions ◽  
Road Friction

Abstract A new method is proposed to estimate and analyze the vehicle lateral stability region, which provides a direct and intuitive demonstration for the safety and stability control of ground vehicles. Based on a four-wheel vehicle model and a nonlinear two-dimensional (2D) analytical LuGre tire model, a local linearization method is applied to estimate the vehicle lateral stability regions by analyzing the vehicle stability at each operation point on a phase plane, which includes but not limited to the equilibrium points. As the collections of all the locally stable operation points, the estimated stability regions are conservative because both vehicle and tire stability are simultaneously considered, which are especially important for characterizing the stability features of highly/fully automated ground vehicles (AGV). The obtained lateral stability regions can be well explained by the vehicle characteristics of oversteering and understeering in the context of vehicle handling stability. The impacts of vehicle lateral load transfer, longitudinal velocity, tire-road friction coefficient, and steering angle on the estimated stability regions are presented and discussed. To validate the correctness of the estimated stability regions, a case study by matlab/simulink and CarSim® co-simulation is presented and discussed.

Estimation and Analysis of Vehicle Lateral Stability Region With Both Front and Rear Wheel Steering

2017 ◽  
Author(s):  
Yiwen Huang ◽  
Yan Chen
Keyword(s):  
Real Time ◽  
Stability Region ◽  
Equilibrium Points ◽  
Estimation Method ◽  
Rear Wheel ◽  
Linearization Method ◽  
Lateral Stability ◽  
Stability Regions ◽  
Explicit Analysis ◽  
Local Linearization Method

In this paper, a novel vehicle lateral stability region estimation method considering both front and rear wheel steering is introduced. Vehicle lateral stability regions are estimated by a local linearization method, which guarantees both vehicle local stability and handling stability. The impacts of front and rear wheel steering angles on stability region estimations are formulated and discussed. To quantitatively explain the shifting feature of stability regions under different front/rear steering angles, an explicit analysis about how the equilibrium points and the geometric centers of stability regions change with respect to different steering angles is formulated. The obtained relationship enables the estimation of stability regions in real time for varying front/rear steering angles. The additional rear wheel steering helps to maintain vehicle states stay within estimated stability regions. To show the effectiveness of the proposed real-time stability region estimation method and stability analysis, a Simulink and CarSim® co-simulation is applied to verify that vehicle states are covered within varying stability regions for a single lane change maneuver.

Vehicle Lateral Motion Control Based on Estimated Stability Regions

2017 ◽  
Author(s):  
Yiwen Huang ◽  
Yan Chen
Keyword(s):  
Measurement Errors ◽  
Local Stability ◽  
Stability Region ◽  
Control Method ◽  
Linearization Method ◽  
Stability Control ◽  
Lateral Stability ◽  
Shortest Distance ◽  
The Stability ◽  
Yaw Moment

This paper presents a novel vehicle lateral stability control method based on an estimated lateral stability region on the phase plane of vehicle yaw rate and lateral speed, which is obtained through a local linearization method. Since the estimated stability region does not only describe vehicle local stability, but also define the oversteering and understeering characteristics, the proposed control method can achieve both local stability and vehicle handling stability. Considering the irregular geometric shape of the estimated stability region, a stability analysis algorithm is designed to determine the distance between vehicle states and stability region boundaries. State estimation or measurement errors are also incorporated in the distance calculation. Based on the calculated shortest distance between vehicle states and stability boundaries, a direct yaw moment controller is designed to maintain vehicle states stay within the stability region. CarSim® and Simulink® co-simulation is applied to verify the control design through a cornering maneuver. The simulation results show that the proposed control method can make the vehicle stay within the stability region successfully and thus always operate in a safe manner.

scholarly journals Modelling of a Partially Loaded Road Tanker during a Braking-in-a-Turn Maneuver

Actuators ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 45 ◽  
Author(s):  
Frank Otremba ◽  
José Romero Navarrete ◽  
Alejandro Lozano Guzmán
Keyword(s):  
Road Safety ◽  
Load Transfer ◽  
Dynamic Interaction ◽  
Performance Measure ◽  
Lateral Stability ◽  
Safety Level ◽  
Factors Associated ◽  
Braking System ◽  
Factors Influencing ◽  
Fill Level

Road safety depends on several factors associated with the vehicle, to the infrastructure, as well as to the environment and experience of vehicle drivers. Concerning the vehicle factors influencing the safety level of an infrastructure, it has been shown that the dynamic interaction between the carried liquid cargo and the vehicle influences the operational safety limits of the vehicle. A combination of vehicle and infrastructure factors converge when a vehicle carrying liquid cargo at a partial fill level performs a braking maneuver along a curved road segment. Such a maneuver involves both longitudinal and lateral load transfers that potentially affect both the braking efficiency and the lateral stability of the vehicle. In this paper, a series of models are set together to simulate the effects of a sloshing cargo on the braking efficiency and load transfer rate of a partially filled road tanker. The model assumes the superposition of the roll and pitch independent responses, while the vehicle is equipped with Anti-lock braking System brakes (ABS) in the four wheels. Results suggest that cargo sloshing can affect the performance of the vehicle on the order of 2% to 9%, as a function of the performance measure considered. A dedicated ABS system could be considered to cope with such diminished performance.

Multi-layer controller with state-constraint: Vehicle lateral stability control based on fuzzy logic

2021 ◽  
pp. 095440702110142
Author(s):  
Neng Wan ◽  
Guangping Zeng ◽  
Chunguang Zhang ◽  
Dingqi Pan ◽  
Songtao Cai
Keyword(s):  
Control System ◽  
Integrated Control ◽  
State Constraint ◽  
Stability Control ◽  
Lateral Stability ◽  
System A ◽  
Velocity Reduction ◽  
Vehicle Velocity ◽  
Allowable Range ◽  
Simulation Results

This paper deals with a new state-constrained control (SCC) system of vehicle, which includes a multi-layer controller, in order to ensure the vehicle’s lateral stability and steering performance under complex environment. In this system, a new constraint control strategy with input and state constraints is applied to calculate the steady-state yaw moment. It ensures the vehicle lateral stability by tracking the desired yaw rate value and limiting the allowable range of the side slip. Through the linkage of the three-layer controller, the tire load is optimized and achieve minimal vehicle velocity reduction. The seven-degree-of-freedom (7-DOF) simulation model was established and simulated in MATLAB to evaluate the effect of the proposed controller. Through the analysis of the simulation results, compared with the traditional ESC and integrated control, it not only solves the problem of obvious velocity reduction, but also solves the problem of high cost and high hardware requirements in integrated control. The simulation results show that designed control system has better performance of path tracking and driving state, which is closer to the desired value. Through hardware-in-the-loop (HIL) practical experiments in two typical driving conditions, the effectiveness of the above proposed control system is further verified, which can improve the lateral stability and maneuverability of the vehicle.

scholarly journals Vehicle Sideslip Angle Estimation Using Two Single-Antenna GPS Receivers

2010 ◽  
Author(s):  
Jong-Hwa Yoon ◽  
Huei Peng
Keyword(s):  
Low Cost ◽  
Longitudinal Velocity ◽  
Stability Control ◽  
Estimation Accuracy ◽  
Measurement Unit ◽  
Sideslip Angle ◽  
Gps Receivers ◽  
Single Antenna ◽  
Active Safety Systems ◽  
Safety Systems

Knowing vehicle sideslip angle accurately is critical for active safety systems such as Electronic Stability Control (ESC). Vehicle sideslip angle can be measured through optical speed sensors, or dual-antenna GPS. These measurement systems are costly (∼$5k to $100k), which prohibits wide adoption of such systems. This paper demonstrates that the vehicle sideslip angle can be estimated in real-time by using two low-cost single-antenna GPS receivers. Fast sampled signals from an Inertial Measurement Unit (IMU) compensate for the slow update rate of the GPS receivers through an Extended Kalman Filter (EKF). Bias errors of the IMU measurements are estimated through an EKF to improve the sideslip estimation accuracy. A key challenge of the proposed method lies in the synchronization of the two GPS receivers, which is achieved through an extrapolated update method. Analysis reveals that the estimation accuracy of the proposed method relies mainly on vehicle yaw rate and longitudinal velocity. Experimental results confirm the feasibility of the proposed method.

Trajectory Generation From Paths for Autonomous Ground Vehicles

2020 ◽  
Author(s):  
Letian Lin ◽  
J. Jim Zhu
Keyword(s):  
Phase Plane ◽  
Longitudinal Velocity ◽  
Initial Boundary ◽  
Limit Function ◽  
Ground Vehicles ◽  
Reverse Time ◽  
Dynamic Constraints ◽  
Autonomous Ground Vehicles ◽  
Practical Concern ◽  
Initial Boundary Condition

Abstract Path-to-trajectory conversion problem for car-like autonomous ground vehicles has been studied in various ways. It is challenging to generate a trajectory which is dynamically feasible for the vehicle and comfortable for the passengers. An important practical concern of low computational costs makes the problem even more difficult. In this work, a path-to-trajectory converter is developed using a novel receding-horizon type suboptimal algorithm. By transforming the dynamic constraints to a longitudinal velocity limit function in the velocity-acceleration phase plane, a time-sub-optimal trajectory satisfying the dynamic constraints and the initial boundary condition is generated by computing the maximum constant acceleration in the down-range horizon. The portion of the trajectory approaching the end of the path is generated in reverse time. As illustrated by some simulation results and validation on a full-scale Kia Soul EV, the proposed path-to-trajectory conversion algorithm is able to account for dynamic constraints of the vehicle and guarantees passenger comfort.

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