Category Archives: News

Newly Published Journal Article: “Vehicle rollover propensity detection based on a mass-center-position metric: a continuous and completed method”

The new journal article, “Vehicle rollover propensity detection based on a mass-center-position metric: a continuous and completed method”, gets published in the IEEE Transactions on Vehicular Technology recently. (See Publications)

Abstract: Rollover index is an essential metric to detect vehicle rollover propensity, which is used to warn a driver or trigger an active rollover prevention system to perform corrective action. To give continuous and completed rollover information, this paper presents a novel rollover index based on a mass-center-position (MCP) metric. The MCP is first determined by estimating the positions of the center of mass of the vehicle, which consists of one sprung mass and two unsprung masses with two switchable roll motion models, before and after tire liftoff. The roll motion information can then be provided through the MCP continuously without saturation for both tripped and untripped rollovers. Moreover, to describe the completed rollover status, different criteria are derived from D’Alembert’s principle and the moment balance conditions based on the MCP. In addition to tire liftoff, three new rollover statuses, “rollover threshold,” “rollover,” and vehicle jumping “in the air,” can be all identified by the proposed criteria. Furthermore, the sensitivity analysis is conducted on some key parameters, such as the sprung/unsprung masses and the height of the center of gravity, to validate the robustness of the proposed detection method. Compared with an existing representative rollover index, lateral load transfer ratio, the fishhook maneuver simulation results in CarSim for an electric vehicle show that the MCP metric can successfully predict vehicle impending rollover status continuously and completely for both untripped and tripped rollovers.

Newly Published Journal Article: “A novel active rollover preventer for ground vehicles based on continuous roll motion detection”

Aug. 17, 2018

The new journal article, “A novel active rollover preventer for ground vehicles based on continuous roll motion detection”, gets published in the ASME ASME Transactions Journal of Dynamic Systems, Measurement and Control recently. (See Publications)

Abstract: To enhance the performance of vehicle rollover detection and prevention, this paper proposes a novel control strategy integrating the mass-center-position (MCP) metric and the active rollover preventer (ARPer) system. The applied MCP metric can provide completed rollover information without saturation in the case of tire lift-off. Based on the continuous roll motion detection provided by the MCP metric, the proposed ARPer system can generate corrective control efforts independent to tire–road interactions. Moreover, the capability of the ARPer system is investigated for the given vehicle physical spatial constraints. A hierarchical control architecture is also designed for tracking desired accelerations derived from the MCP metric and allocating control efforts to the ARPer system and the active front steering (AFS) control. Cosimulations between CarSim and MATLAB/Simulink with a fishhook maneuver are conducted to verify the control performance. The results show that the vehicle with the assistance of the ARPer system can successfully achieve better performance of vehicle rollover prevention, compared with an uncontrolled vehicle and an AFS-controlled vehicle.

Newly Published Journal Article: “Dynamics and control of a novel active yaw stabilizer to enhance vehicle lateral motion stability”

Feb. 24, 2018

The new journal article, “Dynamics and control of a novel active yaw stabilizer to enhance vehicle lateral motion stability”, gets published in the Journal of Dynamic Systems, Measurement, and Control recently. (See Publications)

Abstract: In this paper, a novel active yaw stabilizer (AYS) system is proposed for improving vehicle lateral stability control. The introduced AYS, inspired by the recent in-wheel motor technology, has two degrees of freedom with independent self-rotating and orbiting movements. The dynamic model of the AYS is first developed. The capability of the AYS is then investigated to show its maximum generation of corrective lateral forces and yaw moments, given a limited vehicle space. Utilizing the high-level Lyapunov based control design and the low-level control allocation design, a hierarchical control architecture is established to integrate the AYS control with active front steering (AFS) and direct yaw moment control (DYC). To demonstrate the advantages of the AYS, generating corrective lateral force and yaw moment without relying on tire-road interaction, double lane change maneuvers are studied on road with various tire-road friction coefficients. Co-simulation results, integrating CarSim® and MATLAB/Simulink®, successfully demonstrate that the vehicle with the assistance of the AYS system has better lateral dynamics stabilizing performance, compared with cases in which only AFS or DYC is applied.

Newly Published Journal Article: “Intelligent optimal control for the crawler vehicle with semi-active suspension using modified staged continuous tabu search algorithm”

Oct. 30, 2017

The new journal article, “Intelligent optimal control for the crawler vehicle with semi-active suspension using modified staged continuous tabu search algorithm”, gets published in the Transactions of the Institute of Measurement and Control recently. (See Publications)

Abstract: This paper proposes a novel intelligent optimal control strategy for crawler vehicles with semi-active suspension. The proposed control strategy aims at improving vehicle ride comfort by addressing contradictory suspension properties requirements of ride comfort and handling stability simultaneously. After establishing seven degrees of freedom dynamic model of the crawler vehicle, a comprehensive evaluation index is developed to trade off among various vehicle performances, which include ride comfort, damper thermal reliability, elastic element fatigue and handling stability. Then, using modified staged continuous tabu search (MSCTS) algorithm, the optimal control efforts of semi-active suspension, damping ratios, are determined by minimizing the cost function defined by the comprehensive evaluation index. Demonstrated by simulations with triangle convex block and random ground roughness excitations, MSCTS control strategy can successfully improve ride comfort performance and achieve the optimal comprehensive performance as well.

Fengchen Wang successfully attended the 2017 ASME Dynamic System and Control Conference in Tysons Corner.

Oct. 15, 2017

Fengchen Wang successfully attended the ASME Dynamic System and Control Conference 2017 in Tysons Corner, and he presented his two invited papers, “Vehicle rollover prevention through a novel active rollover preventer” and “Detection of vehicle tripped and untripped rollovers by a novel index with mass-center-position estimations.” (See Publications)