The Experts below are selected from a list of 6996 Experts worldwide ranked by ideXlab platform
N Mutoh - One of the best experts on this subject based on the ideXlab platform.
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dynamics of front and Rear Wheel independent drive type electric vehicles at the time of failure
IEEE Transactions on Industrial Electronics, 2012Co-Authors: N Mutoh, Y NakanoAbstract:In this paper, the failsafe performance of front-and-Rear-Wheel-independent-drive-type electric vehicles (FRID EVs) is clarified from a practical viewpoint through vehicle dynamics analysis under various road conditions and experiments on a running test course. Dynamic analyses at the time of failure were performed under severe road conditions by comparing the vehicle trajectories of FRID EVs with those of conventional EVs, i.e., two- and four-Wheel motor drive-type EVs. The analyzed results show that after failure, FRID EVs continue to run safely and stably; all of the conventional EVs deviate from the travel lane in less than 2 s, which is not sufficient time for an ordinary driver to steer the vehicle to safety after being notified about vehicle failure. Using a prototype FRID EV with practical specifications, failsafe performance at the time of failure was evaluated on test courses, including roads having an ultra-low friction coefficient (μ). The experimental results showed that even if failure occurred while cornering and when running on low- μ roads, the FRID EV continued to run stably. These results proved that FRID EVs could ensure safety at the time of failure under practical running conditions.
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Driving and Braking Torque Distribution Methods for Front- and Rear-Wheel-Independent Drive-Type Electric Vehicles on Roads With Low Friction Coefficient
IEEE Transactions on Industrial Electronics, 2012Co-Authors: N MutohAbstract:This paper focuses on the development of a front- and Rear-Wheel-independent drive-type electric vehicle (EV) (FRID EV) as a next-generation EV. The ideal characteristics of a FRID EV promote good performance and safety and are the result of structural features that independently control the driving and braking torques of the front and Rear Wheels. The first characteristic is the failsafe function. This function enables vehicles to continue running without any unexpected or sudden stops, even if one of the propulsion systems fails. The second characteristic is a function that performs efficient acceleration and deceleration on all road surfaces. This function works by distributing the driving or braking torques to the front and Rear Wheels, taking into consideration load movement. The third characteristic ensures that the vehicle runs safely on roads with a low friction coefficient (μ), such as icy roads. In this paper, we propose a driving torque distribution method when cornering and a braking torque distribution method; these methods are related to the third characteristic, and they are particularly effective when driving on roads with ultralow μ. We verify the effectiveness of the proposed torque control methods through simulations and experiments on the ultralow-μ road surface with a μ of 0.1.
Hiroshi Fujimoto - One of the best experts on this subject based on the ideXlab platform.
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robust yaw stability control for in Wheel motor electric vehicles
IEEE-ASME Transactions on Mechatronics, 2017Co-Authors: Yafei Wang, Hiroshi Fujimoto, Yoichi HoriAbstract:This study investigated robust yaw moment control for motion stabilization in four-Wheel electric vehicles. A two-degree-of-freedom direct yaw moment control scheme is proposed. An engineering weighting function with embedded engineering specifications is included in the proposed approach. The controller was synthesized and its corresponding properties were studied. A Rear-Wheel drive in-Wheel motor electric vehicle was employed for a practical evaluation of the scheme. Because of the robust control framework, the presented system can overcome model uncertainties, side wind disturbances, and parameter variation problems. Experiments were conducted to illustrate the feasibility and effectiveness of the proposed controller.
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electric vehicle range extension control system based on front and Rear Wheel sideslip angle and left and right motor torque distribution
Electrical Engineering in Japan, 2014Co-Authors: Hayato Sumiya, Hiroshi FujimotoAbstract:SUMMARY In this paper, a range extension control system based on the least-squares method is proposed for electric vehicles with in-Wheel motors and front active steering. We propose a method that distributes the front and Rear-Wheel sideslip angles and the difference in the driving force between the left and right motors resulting from the lateral force and yaw moment. The proposed method allows a reduction in the driving resistance generated due to the front steering angle. In practice, the mileage per charge is increased to about 200 m/kWh. Simulations and experiments confirm the effectiveness of the proposed method.
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electric vehicle range extension control system based on front and Rear Wheel sideslip angle and left and right motor torque distribution
Ieej Transactions on Industry Applications, 2012Co-Authors: Hayato Sumiya, Hiroshi FujimotoAbstract:In this paper, the range extension control system based on the least squares method is proposed for electric vehicles with in-Wheel motors and front active steering. We propose a method that distributes front and Rear Wheel sideslip angles and the difference in the driving force between the left and right motors because of the lateral force and yawmoment. The proposed method enables a reduction in the driving resistance generated because of the front steering angle. In fact, the mileage per charge is increased to about 200m/kWh. Simulations and experiments are carried out to confirm the effectiveness of the proposed method.
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distribution method of front Rear Wheel side slip angles and left right motor torques for range extension control system of electric vehicle on curving road
2011Co-Authors: Hayato Sumiya, Hiroshi FujimotoAbstract:In this paper, the range extension control system based on least square method is proposed for electric vehicles with in-Wheel motors and front active steering. This proposed method distributes front and Rear Wheel side-slip angles and driving force difference between left and right motors from lateral force and yaw-moment. The proposed method enables to reduce driving resistance generated from front steering angle. In fact, the mileage per charge is extended up to 200 m/kWh. Simulations and experiments are carried out to confirm the effectiveness of the proposed method.
J. Wang - One of the best experts on this subject based on the ideXlab platform.
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Torque distribution strategy for a front and Rear Wheel driven electric vehicle
6th IET International Conference on Power Electronics Machines and Drives (PEMD 2012), 2012Co-Authors: X. Yuan, J. Wang, K. ColombageAbstract:Electric vehicles (EVs) with a distributed drive train configuration offer great potential and flexibility for improving the system efficiency, performance, reliability as well as safety. This paper investigates a torque distribution scheme for a front and Rear Wheel driven EV in order to improve the drive train efficiency over a wide torque and speed range as a part of the EU funded P-MOB project. It has been shown the maximum efficiency is achieved if the total torque required by the vehicle is shared equally between the two identical motors. In addition, the distribution of the energy consumption over a New European Driving Cycle (NEDC) is analyzed and the regions of high speed, low torque are identified to have a high level of energy consumption, where the motor efficiency improvement in these regions is the most important. Therefore, this paper further proposes to operate just one motor to provide the total required torque in the low torque region. A clutch may be employed between one motor and gearbox (differential), thus “switching off” its idle loss (no-load loss, flux-weakening loss), and improving the drive train efficiency. An online optimized torque distribution algorithm has been devised based on the motor efficiency map to determine whether the second motor should be disengaged by the clutch in the low torque region. With the proposed optimization scheme, the drive train efficiency can be improved by 4% over the NEDC cycle. Experimental test results validate the proposed torque distribution strategy.
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Torque Distribution Strategy for a Front- and Rear-Wheel-Driven Electric Vehicle
IEEE Transactions on Vehicular Technology, 2012Co-Authors: X. Yuan, J. WangAbstract:Electric vehicles (EVs) with a distributed drive train configuration offer great potential and flexibility for improving system efficiency, performance, reliability, and safety. This paper investigates a torque distribution scheme for a front- and Rear-Wheel-driven microsized EV to improve drive train efficiency over a wide torque and speed range. The loss model of the traction permanent-magnet (PM) motor is characterized in both the constant-torque and flux-weakening regions. The relationship between motor efficiency and torque at a given speed is then derived. It has been shown that maximum efficiency is achieved if the total torque required by the vehicle is equally shared between the two identical motors. In addition, the distribution of the energy consumption over a New European Driving Cycle (NEDC) is analyzed, and the regions of high speed and low torque are identified to have a high level of energy consumption; in these regions, motor efficiency improvement is the most important. Therefore, this paper further proposes to operate just one motor to provide the total required torque in the low-torque region. A clutch may be employed between one motor and gearbox (differential), thus “switching off” its idle loss (no-load loss and flux-weakening loss) and improving drive train efficiency. An online optimized torque distribution algorithm has been devised based on the motor efficiency map to determine whether the second motor should be disengaged by the clutch in the low-torque region. With the proposed optimization scheme, drive train efficiency can be improved by 4% over the NEDC. Experimental test results validate the proposed torque distribution strategy.
Alessandro Astolfi - One of the best experts on this subject based on the ideXlab platform.
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shared control for a Rear Wheel drive car dynamic environments and disturbance rejection
IEEE Transactions on Human-Machine Systems, 2017Co-Authors: Jingjing Jiang, Alessandro AstolfiAbstract:This paper studies the shared-control problem for the kinematic model of a group of Rear-Wheel drive cars in a (possibly) dynamic (i.e., time-varying) environment. The design of the shared-controller is based on measurements of distances to obstacles, angle differences, and the human input. The shared-controller is used to guarantee the safety of the car when the driver behaves “dangerously.” Formal properties of the closed-loop system with the shared-controller are presented through a Lyapunov-like analysis. In addition, we consider uncertainties in the dynamics and prove that the shared-controller is able to help the driver drive the car safely even in the presence of disturbances. Finally, the effectiveness of the controller is verified by two case studies: traffic at a junction and at a roundabout.
Wolfgang Sienel - One of the best experts on this subject based on the ideXlab platform.
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robust yaw damping of cars with front and Rear Wheel steering
IEEE Transactions on Control Systems and Technology, 1993Co-Authors: Jurgen Ackermann, Wolfgang SienelAbstract:For a linear model of active car steering, a robust decoupling control law by feedback of the yaw rate to front Wheel steering has previously been derived. This control law is extended by feedback of the yaw rate to Rear Wheel steering. A controller structure with one free damping parameter k/sub D/ is derived with the following properties: damping and natural frequency of the yaw mode are independent of speed; k/sub D/ can be adjusted to the desired damping level; and a variation of k/sub D/ has no influence on the natural frequency of the yaw mode and no influence on the steering transfer function by which the driver keeps the car-considered as a mass point at the front axle-on a planned path. Simulations with a nonlinear car steering model show significant safety advantages of the new control concept in situations when the driver of the conventional car has to stabilize unexpected yaw motions. >
