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In order to make the active suspension more affordable, a novel low-cost active hydraulically interconnected suspension is developed, assembled and tested onto a sport utility vehicle. H∞ roll control strategy is employed to control vehicle body's roll motion. The hydraulic suspension model used for deriving the H∞ controller is estimated experimentally from the testing data. The active suspension model is then combined with the half-car model through their mechanical-hydraulic interface in the cylinders. The weighting function design of the H∞ control is provided. On a 4-post-test rig, the active suspension with H∞ control is validated with several road excitations. The test rig and experimental setup are explained and the obtained results are compared. The effectiveness of the designed H∞ controller is verified by the test data, with a considerable roll angle reduction in the three tests presented.

This paper proposes an approach to optimize the economy performance of a two-speed electric vehicle (EV) by combining gear shifting schedule design and gear ratios selection. Mathematic models for the two-speed EV subsystems are developed, including those of the battery module, electric machine, the driver, transmission and vehicle. Then a procedure for obtaining the optimal gear ratio pairs and corresponding shift schedule for the two-speed EV is presented in detail. The optimized EV powertrain parameters can not only ensure that basic requirements in dynamic performance are achieved, but realize the optimal economic performance of the EV as well. In order to investigate the effectiveness of the proposed method for EV design, simulations based on the developed powertrain model is conducted using different test driving cycles, including NEDC and constant speed. Results of these simulations validate the effectiveness of the proposed optimization method.

In this paper, a previously derived theoretical model of an integrated hydraulically interconnected suspension (HIS) half-car system is experimentally validated. The paper outlines the development of the HIS fluid system model and its integration into a four degree-of-freedom, roll-plane half-car system. An experimental approach to validate the model is outlined, and the resulting purpose-built half-car test facility is described in detail. Experimental results from both free and forced vibration testing are presented and compared with model-based simulations. In general, very good agreement is observed. Limitations of the testing approach and reasons for any discrepancies are discussed. Finally, the broader implications of the obtained results in terms of practical HIS system design are considered.

During normal use vehicles are loaded in multiple configurations that directly alter their inertial properties. A method of accurately identifying and tracking these changes would benefit the many vehicle subsystems that rely on the accuracy of these parameters. In this paper a novel method is presented to determine the inertial properties of a vehicle from the measured sprung mass vibration responses, without the need of sophisticated measuring devices or specialized test rigs. After a brief description of the theoretical basis of the method, experimental results are presented which show estimation of the inertial properties is possible. The results validate the accuracy and applicability of the method and illustrate that the vehicle inertial properties can be obtained even when certain system parameters, such as damping coefficients, are assumed unknown.