Failsafe Drive Performance of FRID Electric Vehicles With the Structure Driven by the Front and Rear Wheels Independently

Failsafe performance is clarified for electric vehicles (EVs) with the drive structure driven by front and rear wheels independently, i.e., front and rear wheel independent drive type (FRID) EV. A simulator based on the four-wheel vehicle model, which can be applied to various types of drive systems like four in-wheel motor-drive-type EVs, is used for the clarification. Yaw rate and skid angle, which are related to drivability and steerability of vehicles and which further influence the safety of vehicles during runs, are analyzed under the condition that one of the motor drive systems fails while cornering on wet roads. In comparison with the four in-wheel motor-drive-type EVs, it is confirmed that the EVs with the structure focused in this paper have little change of the yaw rate and that hardly any dangerous phenomena appear, which would cause an increase in the skid angle of vehicles even if the front or rear wheel drive systems fail when running on wet roads with low friction coefficient. Moreover, the failsafe drive performance of the FRID EVs with the aforementioned structure is verified through experiments using a prototype EV.     

Development of Robust Current 2-DOF Controllers for a Permanent Magnet Synchronous Motor Drive With Reaction Wheel Load

This paper develops robust 2-DOF current and torque control schemes for a permanent magnet synchronous motor (PMSM) drive with satellite reaction wheel load. A DSP-based experimental PMSM-driven reaction wheel system is established, and the key motor parameters are estimated for realizing the proposed control schemes. In the proposed current control schemes, the traditional 2-DOF controller is augmented with an internal model feedback resonant controller or a robust tracking error cancellation controller (RECC). Comparative performance and error analyses of these two proposed control schemes are given. Accordingly, an improved robust 2-DOF current control scheme combining the resonant controller and the RECC is further proposed. The resonant controller enhances the transient and steady-state tracking of the sinusoidal current, simultaneously rejecting the back electromotive force. A similar robust tracking control for the observed torque can be designed, which exhibits quick transient response. Effectiveness of the proposed controls and the driving performance of the whole reaction wheel are evaluated experimentally.      

Hybrid Cascaded H-Bridge Multilevel-Inverter Induction-Motor-Drive Direct Torque Control for Automotive Applications

This paper presents a hybrid cascaded H-bridge multilevel motor drive direct torque control (DTC) scheme for electric vehicles (EVs) or hybrid EVs. The control method is based on DTC operating principles. The stator voltage vector reference is computed from the stator flux and torque errors imposed by the flux and torque controllers. This voltage reference is then generated using a hybrid cascaded H-bridge multilevel inverter, where each phase of the inverter can be implemented using a dc source, which would be available from fuel cells, batteries, or ultracapacitors. This inverter provides nearly sinusoidal voltages with very low distortion, even without filtering, using fewer switching devices. In addition, the multilevel inverter can generate a high and fixed switching frequency output voltage with fewer switching losses, since only the small power cells of the inverter operate at a high switching rate. Therefore, a high performance and also efficient torque and flux controllers are obtained, enabling a DTC solution for multilevel-inverter-powered motor drives.      

Nonlinear MPC-based slip control for electric vehicles with vehicle safety constraints

This paper presents a new slip control system for electric vehicles (EVs) equipped with four in-wheel motors, based on nonlinear model predictive control (nonlinear MPC) scheme. In order to ensure vehicle safety, wheel slip stable zone is considered as time-domain constraints of the nonlinear MPC. Besides, the motor output torque is limited by the motor maximum torque, which varies with motor angular velocity and battery voltage, so the motor maximum output torque limitation is considered as system time-varying constraints. The control objectives include: vehicle safety, good longitudinal acceleration and braking performance, preservation of driver comfort and lower power consumption. This paper utilizes nonlinear MPC to solve this complex optimization control problem subject to the constraints, and the vehicle safety objective is achieved by wheel slip stable zone constraints, the other objectives are realized by adding additional cost functions. In addition, a penalty on the slack variables is also added to ensure that the state constraints (wheel slip) do not cause infeasible problems. The effectiveness of the proposed controller is verified in the off-line co-simulation environment of AMESim and Simulink, and a rapid control prototyping platform based on Field programmable gate array (FPGA) and dSPACE is completed to evaluate the real time functionality and computational performance of the nonlinear MPC controller.     

Nonconventional three-wheel electric vehicle for urban mobility

This paper outlines the original solutions adopted for powering a nonconventional three-wheel electric vehicle. This is a lightweight vehicle for use in urban mobility with mission tasks such as 50 km/h cruising speed and 80 km range of autonomy. The propulsion system is based on a lead-acid battery-fed wheel direct drive. This is arranged with a 4.5 kW prototype of a slotless axial-flux permanent magnet machine, which has a total weight of 15 kg and is capable of 85 Nm continuous torque and 120 Nm peak torque over 2 min. The motor is totally enclosed in the single front wheel of the vehicle and fed through an IGBT bidirectional power converter, which allows the control of both motoring and regenerative braking operations. Design characteristics and experimental data taken from the prototype of wheel direct drive are given     

Direct torque control induction motor drives withself-commissioning based on Taguchi methodology

This paper presents the analysis and design of direct torque control (DTC) induction motor drives with self-commissioning. Neither motor parameters nor controller parameters are known a priori. The self-commissioning process consists of the calculation of motor parameters, including stator resistor, inertia and friction coefficient, as well as the design of the controller. The effects of several factors, including test conditions for deriving motor mechanical parameters and natural frequency for controller design, on the performance of speed response are investigated using Taguchi's method which is widely used in quality engineering to significantly reduce the number of experiments. Therefore, the presented drive system cannot only provide self-commissioning but also dramatically improve the performance of speed response, which is evaluated using the performance index of root-mean-squared error (RMSE) of speed. Experimental results derived from a PC-based experimental system are presented to fully support the theoretical development and analysis     

机线张力数控系统卷绕驱动设计

简述了力矩电机的原理,分析机线张力数控系统卷绕驱动机构的工艺要求,针对普通伺服电机驱动收线轮装置存在的缺陷,提出了用力矩电机控制收线轮的方案。在卷绕驱动机构设计参数确定过程中,阐述了切割线张力形成的原理,并且依据控制电机的选择原则,给出了力矩电机选择计算方法,最终完成了力矩电机控制方式的设计,实现了多线切割恒张力、恒限速度的要求。采用力矩电机驱动收线轮能够使卷绕机构满足系统要求,简化卷绕装置的结构,并能使切割过程运行平稳。     

Nonlinear sliding-mode torque control with adaptive backsteppingapproach for induction motor drive

In this paper, the nonlinear sliding-mode torque and flux control combined with the adaptive backstepping approach for an induction motor drive is proposed. Based on the state-coordinates transformed model representing the torque and flux magnitude dynamics, the nonlinear sliding-mode control is designed to track a linear reference model. Furthermore, the adaptive backstepping control approach is utilized to obtain the robustness for mismatched parameter uncertainties. With the proposed control of torque and flux amplitude, the controlled induction motor drive possesses the advantages of good transient performance and robustness to parametric uncertainties, and the transient dynamics of the induction motor drive can be regulated through the design of a linear reference model which has the desired dynamic behaviors for the drive system. Finally, some experimental results are demonstrated to validate the proposed controllers     

Novel motors and controllers for high-performance electric vehiclewith four in-wheel motors

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·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     

Micro inspection robot for 1-in pipes

A micro inspection robot for 1-in pipes has been developed. The robot is 23 mm in diameter and 110 mm in length and is equipped with a high-quality micro charge-coupled device (CCD) camera and a dual hand for manipulating small objects in pipes. It can travel through both vertical pipes and curved sections, making possible inspections that would be difficult with conventional endoscopes. Its rate of travel is 6 mm/s and it has a load-pulling power of 1 N. To realize this microrobot, the authors have specially designed and developed several micro devices and micromechanisms: a novel micromechanism called a planetary wheel mechanism for robot drive; a micro electromagnetic motor with a micro planetary reduction gear to drive the planetary wheel mechanism; a micro pneumatic rubber actuator that acts as a hand; a micro CCD camera with high resolution; and a pneumatic wobble motor for rotating the camera and hands. In the paper, the design and performance of these micro devices are reported, the performance of the robot as a whole is described, and an application example is given     

混合动力电动汽车用电机及驱动控制器的电磁兼容设计

电机及驱动控制器作为电动汽车的关键部件,其电磁兼容设计对于保证电动汽车的可靠运行非常重要.介绍了国家十五项目中某混合动力轿车用电机及控制器系统的电磁兼容措施,分别从控制电路、信号电缆、功率电路及屏蔽机箱等工程角度进行了分析和设计.该系统的电磁兼容性符合GB/T17619-1998的要求,且已应用于实际混合动力电动汽车,运行情况良好.     

Online Identification of Stator Transient Inductance in Rotor-Flux-Oriented Induction Motor Drive

In a rotor-flux-oriented induction motor drive, stator transient inductance is varied with the change of operating conditions. If the stator transient inductance is not tuned, the field orientation cannot be obtained. As a result, q-axis rotor flux does not become zero, and the performance is deteriorated. This paper shows the problems caused by the detuning of stator transient inductance and proposes a simple online tuning scheme of stator transient inductance for an indirect rotor flux-oriented induction motor drive. Stator transient inductance is estimated only by stator voltage and stator current. The proposed method is verified by simulation and experimental results.     

An advanced permanent magnet motor drive system for battery-poweredelectric vehicles

Availability of high-energy neodymium-iron-boron (Nd-Fe-B) permanent magnet (PM) material has focused attention on the use of the PM synchronous motor (PMSM) drive for electric vehicles (EVs). A new Nd-Fe-B PMSM is proposed for the drive system, which possesses high power density and high efficiency, resulting in greater energy and space savings. The design and optimization of the motor employs finite element analysis and computer graphics. Increasingly, a new PWM inverter algorithm is developed for the drive system, which can handle the nonconstant battery voltage source. An efficiency optimizing control is adopted to further improve the energy utilization of the drive system. Both the control strategy and the PWM generation are implemented in a single-chip microcontroller. As a result, the motor drive achieves high power density, high efficiency, and compactness. A prototype of the 3.2 kW battery-powered drive system has been designed and built for an experimental mini-EV     

Optimal controller design for a matrix converter based surface mounted PMSM drive system

This paper proposes a new control algorithm for a matrix converter permanent magnet synchronous motor (PMSM) drive system. First, a new switching strategy, which applies a backpropagation neural network to adjust a pseudo DC bus voltage, is proposed to reduce the current harmonics of the permanent magnet synchronous motor. Next, a two-degree-of-freedom controller is proposed to improve the system performance. The parameters of this controller are obtained by using a frequency-domain optimization technique. The controller design algorithm can be applied in an adjustable speed control system and a position control system to obtain good transient responses and good load disturbance rejection abilities. The controller design procedures require only algebraic computation. The implementation of this kind of controller is only possible by using a high-speed digital signal processor. In this paper, all the control loops, including current-loop, speed-loop, and position-loop, are implemented by a 32-b TMS320C40 digital signal processor. The hardware, therefore, is very simple. Several experimental results are shown to validate the theoretical analysis.     

Nonconventional on-board charger for electric vehicle propulsionbatteries

Electric vehicles (EVs) are needed in densely populated urban areas to reduce air pollution. Battery chargers are needed to supply DC voltage to charge the high-energy battery parks used in EVs. This paper deals with an on-board battery charger arrangement that is fully based on the use of the power components of the EV motor drive. Desired features for EV battery chargers such as minimum volume, low cost, high efficiency, and high reliability are fully matched by means of the proposed solution. The proposed on-board charger arrangement has been installed on an electric scooter prototype being developed for the Far East markets. Design analysis and experimental results of the on-board charger prototype are presented     

基于Arduino的手势控制智能小车系统设计

文中阐述了一种基于Arduino单片机的手势控制智能小车的设计,其由L298N电机驱动模块、ADXL335角度传感器模块、NRF24L01无线通信模块、麦克纳姆轮及运动控制算法等组成。     

New hybrid fuzzy controller for direct torque control induction motor drives

A new hybrid fuzzy controller for direct torque control (DTC) induction motor drives is presented in this paper. The newly developed hybrid fuzzy control law consists of proportional-integral (PI) control at steady state, PI-type fuzzy logic control at transient state, and a simple switching mechanism between steady and transient states, to achieve satisfied performance under steady and transient conditions. The features of the presented new hybrid fuzzy controller are highlighted by comparing the performance of various control approaches, including PI control, PI-type fuzzy logic control (FLC), proportional-derivative (PD) type FLC, and combination of PD-type FLC and I control, for DTC-based induction motor drives. The pros and cons of these controllers are demonstrated by intensive experimental results. It is shown that the presented induction motor drive is with fast tracking capability, less steady state error, and robust to load disturbance while not resorting to complicated control method or adaptive tuning mechanism. Experimental results derived from a test system are presented confirming the above-mentioned claims.     

简易自动寻迹小车控制器设计

该文主要介绍一种基于单片机的简易自动寻迹小车控制器设计,其硬件主要包括光电传感器介绍与电路设计、两轮驱动介绍与硬件设计以及电源电路设计,软件主要介绍控制方法和策略。该小车采用RPR220光电发射接收一体式传感器根据光线对不同颜色反射红外线强度的不同,来区分白线和黑线,利用LL298N直流电机驱动芯片完成对小车轮的驱动。...     

Parameters and volt-ampere ratings of a synchronous motor drive forflux-weakening applications

This paper deals with the selection of the motor parameters and the inverter power ratings for a permanent magnet (PM) synchronous motor drive in order to meet a given flux-weakening torque versus speed characteristic. Appropriate combinations of stator PM flux linkage, d- and q-axis inductances, and inverter current rating at a given voltage are derived, in normalized values, as functions of the specified flux-weakening speed range and torque limits. By means of these sets of data, the drive designer can easily individuate and compare all the suitable synchronous motors (defined by the d- and q-axis inductances and flux linkage) and the related inverter volt-ampere ratings, for the desired flux-weakening performance. Therefore, this paper can be considered a synthesis work rather than an analysis one and can profitably be used for an optimal design of a synchronous motor drive     

Axial flux machines drives: a new viable solution for electric cars

For electric car propulsion systems, the wheel motor is an application that requires the electrical machine has shape flexibility, compactness, robustness, high efficiency, and high torque. Axial flux machines are an interesting solution, where the motor is directly coupled to, or inside, the drive wheels. In this paper, axial flux induction and synchronous machines as wheel motor applications are presented and some considerations for each motor type are drawn by the authors. The structure with two rotors seems to be a very promising solution for both induction and synchronous machines. In the induction motor case, the two rotors can rotate at different speeds, thus the motor can act as a mechanical differential. The axial flux permanent magnet motor with two rotors is very compact and can be integrated inside the wheel