Motion control in an electric vehicle with four independently driven in-wheel motors
01 Mar 1999-Vol. 4, Iss: 1, pp 9-16
TL;DR: In this paper, a robust dynamic yaw-moment control (DYC) is proposed for an electric vehicle with four independently driven in-wheel motors, which generates yaw from torque differences between the right and left wheels.
Abstract: We study methods of motion control for an electric vehicle (EV) with four independently driven in-wheel motors. First, we propose and simulate a novel robust dynamic yaw-moment control (DYC). DYC is a vehicle attitude control method that generates yaw from torque differences between the right and left wheels. The results of simulations, however, identify a problem with instability on slippery, low /spl mu/ roads. To solve this problem, a new skid detection method is proposed that will be a part of traction control system (TCS) for each drive wheel. The experimental results show that this method can detect a skidding wheel, without any information on chassis velocity. Therefore, this method will be of great help during cornering or braking in a TCS. These methods will be integrated and tested in our new experimental EV.
Citations
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TL;DR: The UOT Electric March II as discussed by the authors is an experimental electric vehicle with four in-wheel motors, which is made for intensive study of advanced motion control of an electric vehicle (EV).
Abstract: The electric vehicle (EV) is the most exciting object to apply "advanced motion control" technique. As an EV is driven by electric motors, it has the following three remarkable advantages: 1) motor torque generation is fast and accurate; 2) motors can be installed in two or four wheels; and 3) motor torque can be known precisely. These advantages enable us to easily realize: 1) high performance antilock braking system and traction control system with minor feedback control at each wheel; 2) chassis motion control like direct yaw control; and 3) estimation of road surface condition. "UOT Electric March II" is our novel experimental EV with four in-wheel motors. This EV is made for intensive study of advanced motion control of an EV.
682 citations
TL;DR: In this article, the authors present the development and experimental characterizations of a prototyping pure electric ground vehicle, which is equipped with four independently actuated in-wheel motors (FIAIWM) and is powered by a 72-V 200-Ah LiFeYPO4 battery pack.
268 citations
TL;DR: Using the estimated sideslip angle and tire cornering stiffness, the vehicle stability control system, making best use of the advantages of IMW-EVs with a steer-by-wire system, is proposed.
Abstract: This paper presents a method for using lateral tire force sensors to estimate vehicle sideslip angle and to improve vehicle stability of in-wheel-motor-driven electric vehicles (IWM-EVs) Considering that the vehicle motion is governed by tire forces, lateral tire force measurements give practical benefits in estimation and motion control To estimate the vehicle sideslip angle, a state observer derived from the extended-Kalman-filtering (EKF) method is proposed and evaluated through field tests on an experimental IWM-EV Experimental results show the ability of a proposed observer to provide accurate estimation Moreover, using the estimated sideslip angle and tire cornering stiffness, the vehicle stability control system, making best use of the advantages of IMW-EVs with a steer-by-wire system, is proposed Computer simulation using Matlab/Simulink-Carsim and experiments are carried out to demonstrate the effectiveness of the proposed stability control system Practical application of lateral tire force sensors to vehicle control systems is discussed for future personal electric vehicles
264 citations
TL;DR: Novel methods for estimating sideslip angle and roll angle using real-time lateral tire force measurements, obtained from the multisensing hub units, for practical applications to vehicle control systems of in-wheel-motor-driven electric vehicles are proposed.
Abstract: Robust estimation of vehicle states (e.g., vehicle sideslip angle and roll angle) is essential for vehicle stability control applications such as yaw stability control and roll stability control. This paper proposes novel methods for estimating sideslip angle and roll angle using real-time lateral tire force measurements, obtained from the multisensing hub units, for practical applications to vehicle control systems of in-wheel-motor-driven electric vehicles. In vehicle sideslip estimation, a recursive least squares (RLS) algorithm with a forgetting factor is utilized based on a linear vehicle model and sensor measurements. In roll angle estimation, the Kalman filter is designed by integrating available sensor measurements and roll dynamics. The proposed estimation methods, RLS-based sideslip angle estimator, and the Kalman filter are evaluated through field tests on an experimental electric vehicle. The experimental results show that the proposed estimator can accurately estimate the vehicle sideslip angle and roll angle. It is experimentally confirmed that the estimation accuracy is improved by more than 50% comparing to conventional method's one (see rms error shown in Fig. 4). Moreover, the feasibility of practical applications of the lateral tire force sensors to vehicle state estimation is verified through various test results.
218 citations
TL;DR: In this paper, a new yaw moment control based on fuzzy logic is proposed to improve vehicle handling and stability, which is obtained from the difference of the brake forces between the front wheels so that the vehicle follows the target values of the yaw rate and the sideslip angle.
Abstract: In this paper, we propose a new yaw moment control based on fuzzy logic to improve vehicle handling and stability. The advantages of fuzzy methods are their simplicity and their good performance in controlling non-linear systems. The developed controller generates the suitable yaw moment which is obtained from the difference of the brake forces between the front wheels so that the vehicle follows the target values of the yaw rate and the sideslip angle. The simulation results show the effectiveness of the proposed control method when the vehicle is subjected to different cornering steering manoeuvres such as change line and J-turn under different driving conditions (dry road and snow-covered).
192 citations
References
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TL;DR: In this article, two novel traction control techniques of an electric vehicle using this advantage are proposed, one is the model-following control and the other is the optimal slip ratio control, which is demonstrated by real experiments using the DC-motor-driven test vehicle "UOT (University of Tokyo) Electric March".
Abstract: The most distinct advantage of the electric vehicle is its quick and precise torque generation. However, most electric vehicles developed to date have not yet utilized this feature. In this paper, two novel traction control techniques of an electric vehicle using this advantage are proposed. One is the model-following control and the other is the optimal slip ratio control. The basic effectiveness of the proposed methods is demonstrated by real experiments using the DC-motor-driven test vehicle "UOT (University of Tokyo) Electric March".
267 citations
TL;DR: In this article, a system of robust unilateral decoupling of car steering dynamics is discussed, where the driver has to concern himself much less with disturbance attenuation, and the important quick reaction to disturbance torques is done by the automatic feedback system.
Abstract: The author discusses a system of robust unilateral decoupling of car steering dynamics. Its effect is that the driver has to concern himself much less with disturbance attenuation. The important quick reaction to disturbance torques is done by the automatic feedback system. The yaw dynamics no longer interfere with the path-following task of the driver. The safety advantages have been demonstrated in experiments with a test vehicle. By empirical improvements, we have modified the controller such that it preserves the robust decoupling advantages for the first 0.5 seconds after a disturbance and then returns the steering authority gradually back to the driver.
188 citations
"Motion control in an electric vehic..." refers background in this paper
...Various controllers for DYC have been proposed [5], [ 6 ]....
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TL;DR: In this paper, a comparison of a linear and a nonlinear observer for the vehicle and tyre side-slip angles is presented, and the modelling, especially the model reduction and simplification, is shown.
164 citations
"Motion control in an electric vehic..." refers background in this paper
...Note that there is feedback for the chassis slip angle . Some papers have reported that estimating seems possible, at least when is small [8], [ 9 ]....
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TL;DR: The design concepts, configuration, and performance of the motor, controller, and drive system developed for this high-performance electric vehicle, designated as the IZA, are described.
Abstract: We have, in accordance with new concepts, undertaken the development of a high-performance electric motor vehicle, designated as the IZA. The main performance features of the IZA are a maximum speed of 176 km/h, a range of 548 km per charge at a constant speed of 30 km/h, and acceleration from 0 to 400 m in 18 s. We have developed a direct driving in-wheel motor and controller in order to achieve high performance characteristics. The in-wheel motor is composed of an outer rotor with a rare earth permanent magnet (Sm-Co) and an inner stator. The motor drive controller consists of a three-phase inverter and a microprocessor-based controller. The maximum output and maximum torque of each total drive system, including motor and inverter, are 25 kW and 42.5 kg/spl middot/m, respectively, and the total efficiency of the drive system is over 90% at the rated speed. The performance of the motor, controller, and drive system have been confirmed by numerous simplex and vehicle transit tests. This paper describes the design concepts, configuration, and performance of the motor, controller, and drive system developed for this high-performance electric vehicle.
141 citations
"Motion control in an electric vehic..." refers background in this paper
...The IZA [ 2 ] has an in-wheel motor for every wheel, and Luciole [3] has one for each rear wheel....
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TL;DR: New designs for the Eco-Vehicle include an in-wheel motor drive system, a hollow load floor which will house the batteries, and a new battery management system.
Abstract: In 1994, the Eco-Vehicle Project was begun to develop an electric vehicle (EV) using a ground-up design approach that incorporates unique designs specific to an EV. The Eco-Vehicle will be a high-performance, but ultrasmall, battery-powered vehicle. New designs for the Eco-Vehicle include an in-wheel motor drive system, a hollow load floor which will house the batteries, and a new battery management system. The Eco-Vehicle may also utilize other advanced concepts suitable especially for EVs, including solar panels for battery charging and intelligent crash avoidance and guidance systems.
111 citations
"Motion control in an electric vehic..." refers background in this paper
...The IZA [2] has an in-wheel motor for every wheel, and Luciole [ 3 ] has one for each rear wheel....
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