The Experts below are selected from a list of 211080 Experts worldwide ranked by ideXlab platform

Xiaoyuan Zhu - One of the best experts on this subject based on the ideXlab platform.

  • a robust wheel slip ratio control design combining hydraulic and regenerative braking systems for in wheel motors driven electric vehicles
    Journal of The Franklin Institute-engineering and Applied Mathematics, 2015
    Co-Authors: Xiaoyu Huang, Junmin Wang, Xuexun Guo, Xiaoyuan Zhu
    Abstract:

    Abstract This paper develops a robust wheel slip controller for in-wheel-motors-driven electric vehicles equipped with both hydraulic anti-lock braking systems (ABS) and regenerative braking (RB) systems. Based on a combination of optimal predictive control design and Lyapunov theory, the issue of uncertain vehicle parameters is well addressed. A novel braking torque Distribution Strategy is also introduced to achieve smooth regulation of the hydraulic pressure, such that pedal pulsating effect of the traditional ABS system can be relieved. By utilizing the larger working range of the hydraulic braking (HB) system and the faster response of the RB system, a better wheel slip control performance can be obtained. Moreover, the torque distributer helps to reach a good compromise between braking distance and the magnitude of the RB torque, which is directly related to the amount of regenerated energy. The effectiveness of the proposed control system has been validated in various simulations.

  • a robust wheel slip control design for in wheel motor driven electric vehicles with hydraulic and regenerative braking systems
    Advances in Computing and Communications, 2014
    Co-Authors: Bin Wang, Xiaoyu Huang, Junmin Wang, Xuexun Guo, Xiaoyuan Zhu
    Abstract:

    A robust wheel slip ratio controller for in-wheel-motor-driven electric vehicles equipped with both hydraulic anti-lock braking systems (ABS) and regenerative braking (RB) systems is designed in this paper. Based on an integration of optimal predictive control design and Lyapunov theory, the issue of uncertain vehicle parameters is addressed. The corresponding braking torque Distribution Strategy between the RB and hydraulic braking (HB) is also introduced to achieve smooth regulation of the brake torque, such that the pedal pulsating effect of the traditional ABS system can be relieved. By utilizing the larger working range of the HB system and the higher bandwidth of the RB system, a better wheel slip ratio control performance can be obtained. The effectiveness of the proposed control system has been validated in Matlab/Simulink simulations.

Jasper De Smet - One of the best experts on this subject based on the ideXlab platform.

  • A Fast and Parametric Torque Distribution Strategy for Four-Wheel-Drive Energy-Efficient Electric Vehicles
    IEEE Transactions on Industrial Electronics, 2016
    Co-Authors: Arash M. Dizqah, Basilio Lenzo, Aldo Sorniotti, Patrick Gruber, Saber Fallah, Jasper De Smet
    Abstract:

    Electric vehicles (EVs) with four individually controlled drivetrains are over-actuated systems, and therefore, the total wheel torque and yaw moment demands can be realized through an infinite number of feasible wheel torque combinations. Hence, an energy-efficient torque Distribution among the four drivetrains is crucial for reducing the drivetrain power losses and extending driving range. In this paper, the optimal torque Distribution is formulated as the solution of a parametric optimization problem, depending on the vehicle speed. An analytical solution is provided for the case of equal drivetrains, under the experimentally confirmed hypothesis that the drivetrain power losses are strictly monotonically increasing with the torque demand. The easily implementable and computationally fast wheel torque Distribution algorithm is validated by simulations and experiments on an EV demonstrator, along driving cycles and cornering maneuvers. The results show considerable energy savings compared to alternative torque Distribution strategies.

Jie Wang - One of the best experts on this subject based on the ideXlab platform.

  • electronic stability control based on motor driving and braking torque Distribution for a four in wheel motor drive electric vehicle
    IEEE Transactions on Vehicular Technology, 2016
    Co-Authors: Li Zhai, Tianmin Sun, Jie Wang
    Abstract:

    An electronic stability control (ESC) algorithm is proposed for a four in-wheel motor independent-drive electric vehicle (4MIDEV) utilizing motor driving and regenerative braking torque Distribution control to improve vehicle stability. A stability judgment controller, an upper level controller, and a torque Distribution algorithm are designed for the ESC system. The stability judgment controller is designed to generate the desired yaw rate and sideslip angle for vehicle stability, and the control mode, which is normal driving mode or ESC mode, is set according to the driver inputs and measurement signal inputs. The upper level controller consists of a speed tracking controller, a yaw moment controller, and four wheel-slip controllers to calculate the desired value of traction force, the desired value of yaw moment, and the four respective net torque inputs of the four in-wheel motors. The torque Distribution algorithm is designed to generate each motor driving torque or regenerative braking torque input for each wheel. An average torque Distribution Strategy, a tire-dynamic-load-based torque Distribution Strategy, and a minimum-objective-function-based optimal torque Distribution Strategy are used separately in the torque Distribution algorithm to control the motor driving torque or regenerative braking torque for vehicle stability enhancement. The proposed ESC algorithm was implemented and evaluated in a CarSim vehicle model and a MATLAB/Simulink control model. The three proposed torque Distribution strategies can be used to regulate the vehicle to perform the following tasks: “single lane change,” “double lane change,” and “snake lane change.” The simulation studies show that the yaw rate error root mean square [RMS $(\gamma-\gamma_\mathrm{-des})$ ] decreased, on average, by 75 percent using the proposed optimal torque Distribution algorithm compared with that without using stability control.

Iksoo Kim - One of the best experts on this subject based on the ideXlab platform.

  • content Distribution Strategy using web cached multicast technique
    International Conference on Computational Science and Its Applications, 2006
    Co-Authors: Backhyun Kim, Iksoo Kim
    Abstract:

    In this paper, we propose content Distribution Strategy to evenly disperse traffic over network and to reduce the required bandwidth for transmitting content data by merging the adjacent multicasts depending upon the number of proxies n that have requested the same one. In our technique, streaming for the identical content is fragmented as long as the grouping interval for batching multicast and can be stored among proxies in order of the requests. A client might have to download data on two channels simultaneously, one from server through multicast and the other from proxies through unicast or multicast. According to the popularity of content, the grouping interval of multicast can be dynamically expanded up to n times and so it can be reduced server's workload and network traffic. We adopt the cache replacement Strategy as LFU (Least-Frequently-Used) for popular content, LRU (Least-Recently-Used) for unpopular content, and the method for replacing the first block of content last to reduce end-to-end latency. We perform simulations to compare its performance with that of conventional multicast. From simulation results, we achieve that the proposed content Distribution Strategy offers significantly better performance.

  • content Distribution Strategy using web cached multicast technioue
    Lecture Notes in Computer Science, 2006
    Co-Authors: Backhyun Kim, Iksoo Kim
    Abstract:

    In this paper, we propose content Distribution Strategy to evenly disperse traffic over network and to reduce the required bandwidth for transmitting content data by merging the adjacent multicasts depending upon the number of proxies n that have requested the same one. In our technique, streaming for the identical content is fragmented as long as the grouping interval for batching multicast and can be stored among proxies in order of the requests. A client might have to download data on two channels simultaneously, one from server through multicast and the other from proxies through unicast or multicast. According to the popularity of content, the grouping interval of multicast can be dynamically expanded up to n times and so it can be reduced server's workload and network traffic. We adopt the cache replacement Strategy as LFU (Least-Frequently-Used) for popular content, LRU (Least-Recently-Used) for unpopular content, and the method for replacing the first block of content last to reduce end-to-end latency. We perform simulations to compare its performance with that of conventional multicast. From simulation results, we achieve that the proposed content Distribution Strategy offers significantly better performance.

Yantao Tian - One of the best experts on this subject based on the ideXlab platform.

  • longitudinal collision avoidance control of electric vehicles based on a new safety distance model and constrained regenerative braking strength continuity braking force Distribution Strategy
    IEEE Transactions on Vehicular Technology, 2016
    Co-Authors: Yufeng Lian, Yun Zhao, Leilei Hu, Yantao Tian
    Abstract:

    This paper presents a new control scheme for longitudinal collision avoidance (CA) systems to improve the safety of four-in-wheel-motor-driven electric vehicles (FIWMD-EVs). There are two major contributions in the design of longitudinal CA systems. The first contribution is a new safety distance model to make vehicle adapt to different driving roads with an adhesive coefficient between tire and road and to conform to drivers' characteristics with a driving intention parameter. The second contribution is a new braking force Distribution Strategy based on constrained regenerative braking strength continuity (CRBSC). By optimizing the braking force Distribution curve of hydraulic proportional-adjustable valve, the safety-brake range could be linearized to simplify the calculation of braking force Distribution on the premise of ensuring braking safety. Furthermore, it is the constraint conditions that could solve the coexistence problem of positive and negative braking forces based on regenerative braking strength continuity (RBSC) to conform to actual requirements. The feasibility, effectiveness, and practicality of the proposed safety distance model and braking force Distribution Strategy are, respectively, verified by computer simulation experiments. Rapid control prototyping (RCP) and hardware-in-the-loop (HIL) simulation experiments using dSPACE are carried out to demonstrate the effectiveness in the control scheme, simplicity in structure, and flexibility in implementation for the proposed longitudinal CA system.

  • a new braking force Distribution Strategy for electric vehicle based on regenerative braking strength continuity
    Journal of Central South University, 2013
    Co-Authors: Yufeng Lian, Yantao Tian, Cheng Yin
    Abstract:

    Regenerative braking was the process of converting the kinetic energy and potential energy, which were stored in the vehicle body when vehicle braked or went downhill, into electrical energy and storing it into battery. The problem on how to distribute braking forces of front wheel and rear wheel for electric vehicles with four-wheel drive was more complex than that for electric vehicles with front-wheel drive or rear-wheel drive. In this work, the frictional braking forces Distribution curve of front wheel and rear wheel is determined by optimizing the braking force Distribution curve of hydraulic proportional-adjustable valve, and then the safety brake range is obtained correspondingly. A new braking force Distribution Strategy based on regenerative braking strength continuity is proposed to solve the braking force Distribution problem for electric vehicles with four-wheel drive. Highway fuel economy test (HWFET) driving condition is used to provide the speed signals, the braking force equations of front wheel and rear wheel are expressed with linear equations. The feasibility, effectiveness, and practicality of the new braking force Distribution Strategy based on regenerative braking strength continuity are verified by regenerative braking strength simulation curve and braking force Distribution simulation curves of front wheel and rear wheel. The proposed Strategy is simple in structure, easy to be implemented and worthy being spread.