The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
According to the characteristic that each wheel torque of 4WD electric vehicle is independent controllable, the control allocation method with a hierarchical structure is adopted to improve the handling stability of the vehicle by optimizing the distribution of motor torque. The controller is composed of an upper controller and a lower controller. Taking the vehicle sideslip angle and yaw rate as...
In this paper, we propose a novel approach to compute minimum-time trajectories for a two-track car model, including tires and (quasi-static) longitudinal and lateral load transfer. Given the car model and a planar track, including lane boundaries, our goal is to find a trajectory of the car minimizing the traveling time subject to steering and tire limits. Moreover, we enforce normal force constraints...
In this paper a torque-to-slip model, oriented to the development of a traction control system based on wheel slip control for powered two-wheelers, is identified. A black-box identification approach is employed to find model parameters, using I/O experimentally measured data. Different tests are employed to analyse different features of the inquired dynamics. In particular, a PRBS based identification...
In this paper we propose a constrained optimal control architecture to stabilize a vehicle near the limit of lateral acceleration using the rear axle electric torque vectoring configuration of an electric vehicle. A nonlinear vehicle and tyre model is employed to find reference steady-state cornering conditions as well as to design a linear Model Predictive Control (MPC) strategy using the rear wheels'...
Controlling vehicle yaw rate is crucial for vehicle safety. In this work, a novel computationally inexpensive yaw rate controller using tyre force measurements is proposed. Most of the yaw rate controllers use a tyre model that introduces modeling error because of the tyre model nonlinearities and uncertainties. This may degrade the controller performance. On the other hand, modeling with tyre force...
This paper presents a vehicle yaw motion control scheme based on the front-wheel lateral force tracking method. The proposed control scheme consists of a yaw rate controller, an active front steering (AFS) controller, and a tire force estimator. The yaw rate controller calculates the front-wheel yaw moment that is required for the vehicle to follow the reference yaw rate. Then the desired front-wheel...
When attempting to drive collision-free paths in emergency situations, automobiles are limited by the amount of force their tires can produce through friction. A road's topography affects the tire forces, so the ability of an autonomous vehicle to follow a desired path depends on the shape of the path in three, not two, dimensions. In this paper, a model that captures the effects of road topography...
This paper presents a hierarchical coordinated control algorithm for integrating active front steering and four-wheel independently driving/braking control. In the higher-level controller, an adaptive siding mode control law and a coordination law for adjusting the yaw rate and slip angle control priorities are applied to determine the desired front wheel steering angle and external yaw moment. In...
Autonomous vehicles can risk dangerous rollover if they corner without taking roll motion into consideration. This paper proposes a control algorithm to follow a curved road while simultaneously preventing rollover. Model predictive control is applied to minimize roll motion throughout cornering. The prediction of vehicle state is based on a four-wheel nonlinear vehicle model with roll dynamics and...
Autonomous vehicles will benefit from the ability to perform aggressive driving maneuvers in safety-critical situations where the full use of available tire-road friction is required. Unfortunately, vehicle steering dynamics become highly nonlinear and difficult to model near the limits of tire adhesion, making accurate control of these maneuvers difficult. One promising approach is to use iterative...
The path following problem for autonomous vehicles (AVs) is investigated in this paper. The desired value of the vehicle heading is commonly chosen as the tangent direction at the orthogonal projection point of vehicle CG (center of gravity) on the desired path. This paper points out that the traditional definition of the desired heading may deteriorate the path following performance, especially when...
This paper investigates two frameworks for interfacing trajectory tracking functions with a computationally tractable nonlinear model predictive trajectory guidance module for an autonomous road vehicle. In the first framework, the predictive trajectory guidance itself is configured in a tracking mode where the control inputs computed by the model predictive control act as targets for some lower-level...
This paper presents a hierarchical approach to feedback-based trajectory generation for improved vehicle autonomy. Hierarchical vehicle-control structures have been used before—for example, in electronic stability control systems, where a low-level control loop tracks high-level references. Here, the control structure includes a nonlinear vehicle model already at the high level to generate optimization-based...
Vehicle yaw moment of inertia is an important parameter for many vehicle dynamic models and control systems yet it is usually difficult to estimate. A methodology in estimating the vehicle yaw moment of inertia is presented in this article by studying the linear relationship between vehicle lateral acceleration, yaw acceleration, and rear wheel lateral tire forces. This linear relationship is derived...
This paper presents a robust guaranteed cost state-delayed control design with applications to in-wheel-motor-driven electric vehicles equipped with active front steering system. The main control objective is to deal with the time delay problem of steering system for improving vehicle lateral stability and handling performance. To address the challenging problem of time delay, the time delay of steering...
This paper presents a novel integrated optimal dynamics control of 4WS4WD electric vehicles via hierarchical control methodology. In the higher-level design, an LQR controller is proposed to obtain the generalized longitudinal force, lateral force and yaw moment, according to their respective reference values. In the lower-level design, the control signals from the higher-level controller are allocated...
Automotive controllers are often first designed in a simulation environment using continuous time models of the controller and vehicle plant. Unfortunately, the controller's implementation in software and deployment onto a microcontroller has ramifications for performance and cost. In this paper, we use an automotive case study of a yaw moment controller to demonstrate that these ramifications can...
This paper investigates the path following problem for four-wheel independently actuated (FWIA) autonomous vehicles (AVs). A novel output constraint controller is proposed to deal with the lateral offset control in path following and maintain the vehicle lateral stability in the presence of tire sliding effects. The innovation of this work includes the following two aspects: (1) A novel output constraint...
This paper investigates the design of robust ℋ∞ control for road vehicle Series Active Variable Geometry Suspension (SAVGS). The objective is to improve ride comfort and road holding, while guaranteeing operation inside existing physical constraints. The study utilizes a nonlinear quarter car model that represents accurately the vertical dynamics and geometry of one quarter of a high performance car...
The paper proposes a method for the improvement of the LPV (Linear Parameter-Varying) based control design for lateral vehicle dynamics. The novelty of the method is the combination of the LPV-based control design and the results of the analysis based on the Sum-of-Squares-based (SOS) polynomial controlled invariant set. In the LPV modeling of the lateral vehicle dynamics, the control design and the...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.