The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Chih-hong Lin - One of the best experts on this subject based on the ideXlab platform.
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Comparative Dynamic Control of SynRM Servodrive Continuously Variable Transmission System Using Blend Amend Recurrent Gegenbauer-Functional-Expansions Neural Network Control and Altered Artificial Bee Colony Optimization
Journal of Dynamic Systems Measurement and Control-transactions of The Asme, 2017Co-Authors: Chih-hong LinAbstract:In comparison control performance with more complex and nonlinear control methods, the classical linear controller is poor because of the nonlinear uncertainty action that the continuously variable transmission (CVT) system is operated by the synchronous reluctance motor (SynRM). Owing to good learning skill online, a blend amended recurrent Gegenbauer-functional-expansions neural network (NN) control system was developed to return to the nonlinear uncertainties behavior. The blend amended recurrent Gegenbauer-functional-expansions NN control system can fulfill overseer control, amended recurrent Gegenbauer-functional-expansions NN control with an adaptive dharma, and recompensed control with a reckoned dharma. In addition, according to the Lyapunov stability theorem, the adaptive dharma in the amended recurrent Gegenbauer-functional-expansions NN and the reckoned dharma of the recompensed controller are established. Furthermore, an altered artificial bee colony optimization (ABCO) yields two varied learning rates for two parameters to find two optimal values, which helped improve convergence. Finally, the experimental results with various comparisons are demonstrated to confirm that the proposed control system can result in better control performance.
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Comparative dynamic control for continuously variable transmission with nonlinear uncertainty using blend amend recurrent Gegenbauer-functional-expansions neural network
Nonlinear Dynamics, 2017Co-Authors: Chih-hong LinAbstract:Because the nonlinear uncertainty of the continuously variable transmission system operated by the synchronous reluctance motor is unknown, control performance obtained for classical linear controller is poor, with comparison to more complex, nonlinear control methods. Due to good learning skill online, a blend amended recurrent Gegenbauer-functional-expansions neural network (NN) control system was developed to return to the nonlinear uncertainties behavior. The blend amended recurrent Gegenbauer-functional-expansions NN control system can fulfill overseer control, amended recurrent Gegenbauer-functional-expansions NN control with an adaptive dharma and recompensed control with a reckoned dharma. In addition, according to the Lyapunov stability theorem, the adaptive dharma in the amended recurrent Gegenbauer-functional-expansions NN and the reckoned dharma of the recompensed controller are established. Furthermore, an altered artificial bee colony optimization yields two varied learning rates for two parameters to find two optimal values, which helped improving convergence. Finally, various comparisons of the experimental results are demonstrated to confirm that the proposed control system can result better control performance.
Sohel Anwar - One of the best experts on this subject based on the ideXlab platform.
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predictive yaw stability control of a brake by wire equipped vehicle via eddy current braking
American Control Conference, 2007Co-Authors: Sohel AnwarAbstract:Yaw stability of an automotive vehicle in a steering maneuver is critical to the overall safety of the vehicle. In this paper we present a theoretical development and experimental results of a vehicle yaw stability control system via eddy current braking based on generalized predictive control (GPC) method. The controller tries to predict the future yaw rate of the vehicle and then takes control action at present time based on future yaw rate error. The proposed controller utilizes the insight into the yaw rate error growth when the automobile is in an understeer or Oversteer condition on a low friction coefficient surface in a handling maneuver. A brake-by-wire equipped vehicle having a set of four eddy current brakes was used to experimentally verify the proposed control algorithm. Experimental results show that the predictive feature of the proposed controller provides an effective way to control the yaw stability of a vehicle.
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Yaw stability control of an automotive vehicle via generalized predictive algorithm
Proceedings of the 2005 American Control Conference 2005., 2005Co-Authors: Sohel AnwarAbstract:Yaw stability of an automotive vehicle in a steering maneuver is critical to the overall safety of the vehicle. In this paper, we present a theoretical development and experimental results of a vehicle yaw stability control system based on generalized predictive control (GPC) method. The controller tries to predict the future yaw rate of the vehicle and then takes control action at present time based on future yaw rate error. The proposed controller utilizes the insight into the yaw rate error growth when the automobile is in an understeer or Oversteer condition on a low friction coefficient surface in a handling maneuver. Experimental results show that the predictive feature of the proposed controller provides an effective way to control the yaw stability of a vehicle.
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A predictive control algorithm for a yaw stability management system
SAE transactions, 2003Co-Authors: Sohel AnwarAbstract:This paper describes how generalized predictive control (GPC) is a discrete time control strategy that was proposed by Clark et al. The controller tries to predict the future output of a system or plant and then takes control action at present time based on future output error. Such a predictive control algorithm is presented in this paper for yaw stability management of an automobile. Most of the existing literature on the yaw stability management systems lacks the insight into the yaw rate error growth when the automobile is in a understeer or Oversteer condition on a low friction coefficient surface in a handling maneuver. Simulation results show that the predictive feature of the proposed controller provides an effective way to control the yaw stability of a vehicle.
Changle Xiang - One of the best experts on this subject based on the ideXlab platform.
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An AWID and AWIS X-By-Wire UGV: Design and Hierarchical Chassis Dynamics Control
IEEE Transactions on Intelligent Transportation Systems, 2019Co-Authors: Jun Ni, Jibin Hu, Changle XiangAbstract:In this paper, an all-wheel independently driven and all-wheel independently steered unmanned ground vehicle (UGV) is described. This paper investigates the hierarchical chassis yaw dynamics control (CYDC) and the tyre force control of the UGV in the remote control mode (RCM). The hierarchical CYDC scheme in RCM is proposed. As the key part in the control scheme, a yaw moment controller is proposed to deal with the Oversteer problem of the UGV. Through the robust-based pole placement technique, the ideal poles' zones of the lateral UGV dynamics system are able to be tuned to meet different dynamics behavior requirements in different UGV tasks. The robust state feedback yaw dynamics controller is investigated based on the linear matrix inequalities approach. It considers the unavoidable parametric disturbance and uncertainty, such as the variation of the UGV's mass, yaw inertia, and tyre-road characteristics. In addition, in order to improve its performance in off-road conditions, the tyre traction force distribution algorithm and sliding mode wheel slip controller are designed to negotiate uneven terrains. The experiments in paved and off-road conditions are conducted to demonstrate the performance of the proposed controller.
David A Renfroe - One of the best experts on this subject based on the ideXlab platform.
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An Analysis of the Mechanism Causing Loss of Control During a Tire Delamination
2009Co-Authors: David A Renfroe, Alex RobertsAbstract:Electronic controls cannot always compensate for the destabilization of a poorly designed vehicle caused by tire delamination. Axle tramp caused from rubber strips on the track showed axle skate. Further research, reported at ESV 2007 demonstrated that lumps on a single rear tire caused 15+ degrees/g of Oversteer. The Engineering Institute has shown that the process of tire delamination causes some vehicles to become unstable at highway speeds. This was accomplished by actually preparing tires to partially delaminate while at 95 to 115 kph on a remotely controlled vehicle. This testing demonstrated a severe loss of control as the tire was delaminating. The testing also showed that the predominate mechanism of control loss arises from the imbalance created during the delamination process. A discussion of the testing illustrating accelerations on the rear axle as well as displacements of the shock absorbers will be used to illustrate the imbalance excitation and the tramping motion of the axle. Previous research indicated that the Oversteer gradient during such an event to be between 15 and 20 degrees per g. This would then yield a critical speed of about 45 kph. The testing illustrates how a vehicle loses control when the vehicle transitions from understeer to Oversteer at highway speeds significantly above the critical speed from tire failure induced forces. Alternative suspensions were tested using the same simulated tire failure and illustrated how the vehicle stability is increased. Using these results, a design criteria based upon a percentage of the critical rotational damping is proposed to control axle tramp from excitations at the harmonic frequency. The full text of this paper may be found at: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv21/09-0209.pdf For the covering abstract see ITRD E145407.
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quantitative measure of transient Oversteer of road vehicles
20th International Technical Conference on the Enhanced Safety of Vehicles (ESV)National Highway Traffic Safety Administration, 2007Co-Authors: David A Renfroe, Paul T Semones, Alex RobertsAbstract:When discussing Oversteer of a vehicle, reference is made to results of the SAE J266 circle test or gradually increasing steer test. However, these tests demonstrate the vehicle’s characteristics at a quasistatic condition and do not consider the dynamic effects of the moment of inertia of the vehicle or of the wheelbase and tire characteristics during yaw accelerations occurring in transient maneuvers. Frequently, there are discussions of the transitional effects on Oversteering of the vehicle and reference may be made to the radius of gyration squared versus the product of the front and rear distances from the axles to the CG. This particular relationship, however, assumes that the tire lateral capabilities on the front and the rear are the same. This paper will discuss the comparison of the “Ackermann yaw rate” versus the measured yaw rate in transient steer maneuvers such as the step steer. The Ackermann yaw rate will be the yaw rate developed if the vehicle were to track exactly along the direction that the wheels are pointing. If this theoretical yaw rate is compared to the measured yaw rate, a vehicle’s transitional handling characteristics can be quantified. An example where there has been considerable discussion is with the 15-passenger van. Loss of control of these vans, attributed to Oversteer when attempting an accident avoidance maneuver, has been discussed extensively by government and private groups. That Oversteer occurs even though these vans exhibit understeering characteristics when tested with the J266 protocol up to a transition to Oversteer at the vehicle’s lateral adhesion limit. The technique described here allows the transitional Oversteer characteristic of any vehicle to be quantified. This will help to explain and quantify the characteristic causing loss of control of these vans and other similar vehicles.
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Effects of the Process of Rear Tire Delamination on Vehicle Stability
2007Co-Authors: David A Renfroe, H. Alex Roberts, David BeltranAbstract:The effects of the delaminated tire after a tread separation event on the handling of a vehicle have been well documented. However, the period when the tire is delaminating, which can last from about one and one half to many seconds, can pose a serious threat to vehicle stability depending on the duration of the delamination process, the design of the rear suspension of the vehicle, and the speed at which the delamination commences. This paper will present the results of testing where a delaminating tire results in a bump on the tire and a subsequent loss of control even with expert drivers. Similar vehicles were tested under a controlled environment to determine that the cause of the loss of control is axle tramp induced by the bump frequency of the delamination occurring at the natural frequency of the axle/spring (the tire is the dominant spring) system. During this tramping the handling characteristics become severely Oversteer. The resulting Oversteer has been measured using standard SAE J266 test procedures for various models of vehicles characterized by a Hotchkiss type rear suspension system. Proposed solutions were increasing the tramp damping characteristics of the axle system and/or the addition of dual wheels on certain vehicles. These solutions are examined for their effectiveness. Testing will illustrate how proper shock absorber sizing and placement will have a positive effect on the Oversteer situation.
Todd Allen Brown - One of the best experts on this subject based on the ideXlab platform.
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control of regenerative braking during a yaw stability control event
2004Co-Authors: Todd Allen Brown, Michael John SchneiderAbstract:The present invention is a method and system to control regenerative braking during the operation of a yaw stability control system. The method and system use feedback control algorithms to monitor and dynamically modify regenerative and non-regenerative braking. The controller can use a simple proportional-integral-derivative feedback controller. A vehicle yaw stability control system can determine if a vehicle is experiencing an Oversteer or understeer condition. The controller compares actual brake balance to a desired brake balance. The controller determines if the front axle wheels are overbraked relative to the rear axle wheels or if the rear axle wheels are overbraked relative to the front axle wheels as compared to the desired brake balance. The controller can adjust regenerative braking and non-regenerative braking levels according to the determinations.
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braking and controllability control method and system for a vehicle with regenerative braking
2004Co-Authors: Todd Allen BrownAbstract:The present invention provides a method and system to use feedback control algorithms to monitor and dynamically modify front and rear braking torque to initiate braking based on driver demand, initially favoring regenerative braking more than conventional braking balance would indicate while monitoring and maintaining vehicle controllability factors such as Oversteer and understeer. A simple proportional-integral-derivative feedback controller can be used. Vehicle sensors for wheel speed, lateral acceleration, yaw rate, and brake position can provide input to the controller to monitor vehicle conditions and to activate non-regenerative and regenerative braking in varying proportions based on at least one actual vehicle controllability value and predetermined target value for controllability and optimization of energy recovery. Controllability factors can include predetermined longitudinal wheel slip ratios or a comparison of tire slip angle or yaw rate to a target value.
