Youcef Ait-Amirat

Modeling and simulation of a traction control algorithm for an electric vehicle with four separate wheel drives

The aim of this paper is to present a traction control algorithm for an electric vehicle (EV) with four separate wheel drives. This algorithm is necessary to improve the handling and stability of EV during cornering or under slippery road conditions. It distributes the traction power among four drives and especially an independent torque reference on each wheel. The proposed algorithm is implemented in terms of a hierarchical architecture, which incorporates all new known vehicle systems ABS (anti-lock brake system), ASR (anti slip regulation), ESP (electronic stability program). To achieve good performance a correlation of the traction controller with motor performance has been implemented. Several simulation results, which show the potential of such a algorithm, are presented.The aim of this paper is to present a traction control algorithm for an electric vehicle (EV) with four separate wheel drives. This algorithm is necessary to improve the handling and stability of EV during cornering or under slippery road conditions. It distributes the traction power among four drives and especially an independent torque reference on each wheel. The proposed algorithm is implemented in terms of a hierarchical architecture, which incorporates all new known vehicle systems ABS (anti-lock brake system), ASR (anti slip regulation), ESP (electronic stability program). To achieve good performance a correlation of the traction controller with motor performance has been implemented. Several simulation results, which show the potential of such a algorithm, are presented.

Position Control of a Sensorless Stepper Motor

In this paper, the experimental results of position control of the hybrid stepper motor without a mechanical sensor are exhibited. Use of the steady-state extended Kalman filter to estimate the mechanical variables of the motor is shown. With this method the computing time is reduced. The initial rotor position is estimated by the impulse voltage technique. For position control, a simple state feedback control that can compensate the load torque variations was designed. The robustness against the motor parameters variation was also studied. A field-oriented control strategy is chosen. It is known that the mechanical position is crucially important to achieve this strategy. Finally, favorable experimental results are shared.

Sensorless control of hybrid stepper motor

Today thanks to low cost and high performance DSPs, Kalman filtering (KF) becomes an efficient candidate to avoid mechanical sensors in motor control. We present in this work experimental results by using a steady state KF method to estimate the speed and rotor position for hybrid stepper motor. With this method the computing time is reduced. The Kalman gain is pre-computed from numerical simulation and introduced as a constant in the real time algorithm. The load torque is also on-line estimated by the same algorithm. At start-up the initial rotor position is detected by the impulse current method.

Fault detection in 3-phase Traction Motor using Artificial Neural Networks

Traction Motors Condition Monitoring is one of the important factors in increasing motor life time and prevention of any train sudden stop in track and thereupon avoiding interruptions in track traffic. In this paper, a neural network based method for detecting unbalanced voltage fault which is one of the various faults in 3-phase traction motors was surveyed. Proposed method is independent from load state and fault percentage; which means neural network is able to detect fault and load condition without any assumption about the state of the load and fault. In proposed method, two separate neural networks are used for each problem. Experimental acquired data is used to train neural networks. Based on first test results, the neural structure could detect unbalanced voltage fault percentage with 98.5% precision. Also, based on second test results, the neural network could detect load condition accurately in 97% of the cases. According to these results, neural network is a good choice for solving similar problems.

DSP Implementation of Rotor Position Detection Method for Hybrid Stepper Motors

To improve the dynamic performance of the stepper motor it can be driven with a closed loop control. For sensorless control, initial rotor position detection is one of the serious problems. At standstill, if the rotor position is inaccurately detected, the stepper motor can move in the wrong direction or do not start at all. The method that uses inductance saliency to detect the initial rotor position is very suitable for hybrid Stepper motor (HSM) which is highly saturated. This paper will present experimental results for the initial rotor position estimation. At standstill, a sequence of voltage pulses is applied and the measured peak current gives information about rotor position. The DSP System used for the implementation is based on the powerful DS 1103 controller board from dSPACE. It allows programming dynamic real-time systems using Matlab/Simulink environment

Nonlinear feedback control and trajectory tracking of vehicle

This paper mainly studies nonlinear feedback control applied to the nonlinear vehicle dynamics with varying velocity. The main objective of this study is the stabilisation of longitudinal, lateral and yaw angular vehicle velocities. To this end, a nonlinear vehicle model is developed which takes both the lateral and longitudinal vehicle dynamics into account. Based on this model, a method to build a nonlinear state feedback control is first designed by which the complexity of system structure can be simplified. The obtained system is then synthesised by the combined Lyapunov–LaSalle method. The simulation results show that the proposed control can improve stability and comfort of vehicle driving. Moreover, this paper presents a lemma which ensures the trajectory tracking and path-following problem for vehicle. It can also be exploited simultaneously to solve both the tracking and path-following control problems of the vehicle ride and driving stability. We also show how the results of the lemma can be applied to solve the path-following problem, in which the vehicle converges and follows a designed path. The effectiveness of the proposed lemma for trajectory tracking is clearly demonstrated by simulation results.

Design of an actuator for the fast and high accuracy Wire Scanner

This paper presents the design of the actuator for the fast and high accuracy Wire Scanner system. The actuator consists of a rotary brush-less synchronous motor with the permanent magnet rotor installed inside of the vacuum chamber and the stator installed outside. Fork, permanent magnet rotor and two angular position sensors are mounted on the same axis and located inside the beam vacuum chamber. The system has to resist a bake-out temperature of 200°C and ionizing radiation up to tenths of kGy/years. The requirements imply a maximum angular speed of 210 rad.s-1 an required acceleration of 20 000 rad.s-1 and a angular position measurement accuracy of 5 arc seconds. The system must deal with extremely low vibration and low electromagnetic interference. A digital feedback controller will allow maximum flexibility for the loop parameters and feeds the 3 phases linear power driver. The performances of the presented design are investigated through simulations and experimental tests.

Nonlinear feedback control of Vehicle Speed

Abstract This paper deals with the development of a nonlinear static state feedback control applied to the vehicle speed. The control is obtained by suitable change of variable and after some preliminary feedback. The main objective in this study is the stabilization of vehicle velocities, i.e longitudinal, lateral and yaw rate using Lyapunouv stability theory and LaSalle invariance principle.

Global modeling and simulation of vehicle to analyze the inertial parameters effects

This paper mainly studies the comparison of the global vehicle models and the effects of the inertial parameters due to the center of gravity (CG) positions when we consider that the vehicle has only one CG. This paper proposes a new nonlinear model vehicle model which considers both unsprung mass and sprung mass CG. The CG positions and inertial parameters effects are analyzed in terms of the published vehicle dynamics models. To this end, two 14 degree-of-freedom (DOF) vehicle models are developed and compared to investigate the vehicle dynamics responses due to the different CG height and inertial parameters concepts. The proposed models describe simultaneously the vehicle motion in longitudinal, lateral and vertical directions as well as roll, pitch and yaw of the vehicle about corresponding axis. The passive and active moments and the forces acting on the vehicle are also described and they are considered as a direct consequence of acceleration, braking and steering maneuvers. The proposed model M1 takes both the CG of sprung mass, unsprung mass and total vehicle mass into account. The second model M2 assumes that the vehicle is one solid body which has a single CG as reported in majority of literature. The two vehicle models are compared and analyzed to evaluate vehicle ride and handling dynamic responses under braking/acceleration and cornering maneuvers. Simulation results show that the proposed model M1 could offer analytically some abilities and driving performances, as well as improved roll and pitch in a very flexible manner compared to the second model M2.

Fault detection investigation in a full bridge thyristor base AC-DC converter

In this paper firstly, best method identification for data acquisition selection by aim of fault analysis is presented and in continue, a new pattern for a full bridge thyristor base AC-DC converter under failure in view of series hybrid electric vehicle (SHEV) application is identified and presented by the help of experimental test result. Open phase signatures are utilized to introduce a particular frequency pattern, and side-band components changes at proposed frequencies are employed as a proper index for fault recognition.