Lateral Stability Analysis for Car-Trailer Combinations

This paper presents a parametric study of linear lateral stability of a car-trailer (CT) combination in order to examine the fidelity, complexity, and applicability for control algorithm development for CT systems. Using MATLAB software, a linear yaw-roll model with 5 degrees of freedom (DOF) is developed to represent the CT combination. In the case of linear stability analysis, a parametric study was carried out using eigenvalue analysis based on a linear yaw-roll CT model with varying parameters. Built upon the linear stability analysis, an active trailer differential braking (ATDB) controller was designed for the CT system using the linear quadratic regulator (LQR) technique. The simulation study presented in this paper shows the effectiveness of the proposed LQR control design and the influence of different trailer parameters.

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A Study of the Lateral Stability of Railroad Vehicles Using a Nonlinear Constrained Multibody Formulation

10.1115/imece2001/rtd-25704 ◽

2001 ◽

Author(s):

Davide Valtorta ◽

Khaled E. Zaazaa ◽

Ahmed A. Shabana ◽

Jalil R. Sany

Keyword(s):

Stability Analysis ◽

Linear Stability ◽

Linear Theory ◽

Linear Stability Analysis ◽

Numerical Study ◽

Operating Conditions ◽

Lateral Stability ◽

Railroad Vehicles ◽

Contact Formulation ◽

The Stability

Abstract The lateral stability of railroad vehicles travelling on tangent tracks is one of the important problems that has been the subject of extensive research since the nineteenth century. Early detailed studies of this problem in the twentieth century are the work of Carter and Rocard on the stability of locomotives. The linear theory for the lateral stability analysis has been extensively used in the past and can give good results under certain operating conditions. In this paper, the results obtained using a linear stability analysis are compared with the results obtained using a general nonlinear multibody methodology. In the linear stability analysis, the sources of the instability are investigated using Liapunov’s linear theory and the eigenvalue analysis for a simple wheelset model on a tangent track. The effects of the stiffness of the primary and secondary suspensions on the stability results are investigated. The results obtained for the simple model using the linear approach are compared with the results obtained using a new nonlinear multibody based constrained wheel/rail contact formulation. This comparative numerical study can be used to validate the use of the constrained wheel/rail contact formulation in the study of lateral stability. Similar studies can be used in the future to define the limitations of the linear theory under general operating conditions.

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Design Optimization of Car-Trailer Combinations With Electronic Stability Systems

Volume 12: Transportation Systems ◽

10.1115/imece2014-36477 ◽

2014 ◽

Author(s):

Tao Sun ◽

Yuping He

Keyword(s):

Controller Design ◽

Linear Quadratic Regulator ◽

Lateral Stability ◽

Trial And Error ◽

Linear Quadratic ◽

Weighting Factors ◽

Lqr Controller ◽

Ct System ◽

Trial And Error Method ◽

Error Method

To date, Linear Quadratic Regulator (LQR) controllers based on linear vehicle models have been researched and developed for improving the lateral stability of car-trailer (CT) combinations. However, in the LQR controller design, there is no a systematic way to determine the weighting factors of the performance index. Generally, the weighting factors are selected using trial and error based on designer’s experience. In order to facilitate the LQR controller design, a new method based on a genetic algorithm (GA) is presented to determine the appropriate weighting factors in the LQR controller design. To examine the proposed method, a controller for an active trailer differential braking (ATDB) system of a car-trailer (CT) system is designed and examined. The simulation results indicate that compared with the LQR controller based on the weighting factors derived from the conventional trial and error method, the controller developed using the proposed method exhibits better performance.

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