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

Abstract

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 Stability Regions for Control Applications

“…In [4], [5], [14], simplifications were made so as to obtain a linearized model, which is the standard approach in the literature, e.g., [2], known as the bicycle model. They are, however, different models.…”

“…Common approaches to vehicle stability deal with system stability and controllability, as they are inherent to one another, in a practical sense [4], [5]. A driver wants the vehicle to remain stable, so he is able to control it.…”

“…And he needs the vehicle to be controllable, so as to remain stable on the desired trajectory [6]- [8]. The majority of the works on the subject considers either a phase portrait of a simplified system [4], [8]- [12] or the linearized system characteristic equation [4], [5], [13], [14] to evaluate system stability. This does not imply, naturally, that other approaches have not been presented, for instance, Lyapunov techniques [15], [16].…”

Integrated Chassis Control and Control Allocation for All Wheel Drive Electric Cars with Rear Wheel Steering

“…The integration of the two controllers uses the current understeering coefficient, which is calculated using Equation ( 16) with parameters estimated from a Kalman filter. The threshold is designed to maintain neutral steering behavior using the definition in [15], as expressed in Equation (34). Note that the threshold is tunable, depending on the limits of the design or driver preference.…”

Adaptive yaw stability control by coordination of active steering and braking with an optimized lower‐level controller

“…19,20 Second, using the phase portrait of the lateral speed and the yaw rate. 21,22 Another way to maintain vehicle stability is to determine the range of braking and steering forces based on the tire-road friction coefficient and tire load. 23 To ensure the stability and handling of the vehicle, the necessary coordination between the brake and the steering must be established through an appropriate control mechanism to maintain the vehicle in the safe region defined by each of the above strategies.…”