Publications (4)3.43 Total impact
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ABSTRACT: This paper presents the design and implementation of a semi-active suspension control system for a light commercial vehicle using continuously varying dampers, accelerometers, and an onboard processor. The control algorithms such as sky-hook, ground-hook, and hybrid are designed based on the vertical velocities of each quarter of the car. These velocities are estimated from Kalman filter using quarter car vehicle model. The controllers are implemented in an actual vehicle equipped with the developed semiactive suspensions system and their performance are compared. Sky-hook control improved ride comfort by reducing body accelerations in the 1-3 Hz range, ground-hook control improved road holding by reducing wheel accelerations in the 10-15 Hz range, and hybrid control results were in between the sky-hook and ground-hook results. The main contribution of this paper is the successful implementation of the semiactive suspension control strategies on an actual vehicle with accompanying experimental results.
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ABSTRACT: This paper is on designing a multi-objective, robust parameter space steering controller for yaw stability improvement of a light commercial vehicle and its testing on a hardware-in-the-loop steering test rig. A linear single track model of the light commercial vehicle is used for controller design while its nonlinear version is used during hardware-in-the-loop simulations. The multi-objective design method used here maps D-stability, mixed sensitivity and phase margin bounds into the parameter space of chosen disturbance observer based steering controller filter parameters. The resulting controller design is tested using offline and hardware-in-the-loop simulations. A hardware-in-the-loop simulation test rig with the actual rack and pinion mechanism of the light commercial vehicle under study was built for this purpose. The steering control actuator is placed on the second pinion of the double pinion steering test system used. The hardware and geometry of the steering test rig are identical to the implementation of the steering system in the test vehicle. Unnecessary and expensive road testing is avoided with this approach as most problems are identified and solved in the hardware-in-the-loop simulation phase conducted in the laboratory where the steering subsystem and its controller exist as hardware and the rest of the vehicle being implemented exists as real time capable software. Hardware-in-the-loop simulation results show the effectiveness of the controller design proposed in this paper in tracking desired steering dynamics and in rejecting yaw disturbance moments.
Conference Paper: Model regulator based individual wheel braking control[Show abstract] [Hide abstract]
ABSTRACT: Yaw stability control systems are important components of active safety systems for road transport. A model regulator based yaw stability control system that was previously implemented and tested very successfully as a steering controller is adapted to work as an individual wheel braking controller in this paper. A two track nonlinear vehicle model is used to test the individual wheel braking actuated model regulator developed here. Simulation results are used to demonstrate the achievement of good yaw disturbance moment rejection by the proposed controller.
Conference Paper: HIL system for steering controller tests[Show abstract] [Hide abstract]
ABSTRACT: Yaw stability control is an important consideration in active safety of road transport. As steer by wire systems are now commercially available, steering actuated yaw stability controllers are expected to become more significant. The steer by wire actuator bandwidth and saturation limits may set achievable performance constraints on such steering controllers. This paper focuses on hardware in the loop (HIL) testing of steering controllers to investigate such performance problems. A HIL steering controller test setup is presented in this paper for that purpose.