Wang Dafang

A Feedback-Type Phase Voltage Compensation Strategy Based on Phase Current Reconstruction for ACIM Drives

Insertion of dead time, transfer links between micro control unit (MCU) and voltage source inverter (VSI), VSIs nonideal characteristics all lead to deviation that cannot be ignored between the actual output voltage and the command voltage, which seriously affects the performance of the ac induction motor (ACIM) control system. Among many dead-time effect compensation methods, VSI usually operates under an open-loop condition, thus making complete compensation hard to achieve. This paper studies methods to obtain the two key elements of compensation voltage amplitude and current polarity and a novel phase voltage compensation method is proposed. In this method, a simple hardware circuit is applied to obtain the actual output of the VSI as feedback with which precise compensation amplitude can be calculated. And judgment of current polarity is accurately realized by reconstructing phase current from filtered current components under M-T coordinate with a Kalman filter. The compensation in a zero-crossing region is also closely discussed in this paper. To verify the validity of the method, simulations and experiments are carried out. The experiments emphasize on the efficacy of feedback, steady-state, and transient performance of current reconstruction; and the performance of a conventional method to that of the proposed method are also compared. Results show that the proposed method proves to be effective.

Basic Concepts on AUTOSAR Development

AUTOSAR(AUTomotiveOpen System ARchitecture) is an open and standardized automotive software architecture, jointly developed by automobile manufacturers, suppliers and tool developers. The AUTOSAR standard will serve as a platform upon which future vehicle applications will be implemented and will also serve to minimize the current barriers between functional domains. To improve cost-efficiency and reusability, AUTOSAR separates application software from the associated hardware. This stage, AUTOSAR is still in the promotion phase, and many countries are committed to its applications, including Japan and South Korea. It will widespread in automotive industry. This paper showed the basic concepts of AUTOSAR and comparisons of some confusing concepts for future in-depth study.

Research progress of switched reluctance motor drive system

With the energy shortage and environmental problems in modern society, many developed countries pay attention to the research on the electric vehicle which can realize the energy-saving. The electric machine is a key part of the electric vehicle. And the switched reluctance motor takes a lot of merits comparing to the other motor so that it becomes the preferred machine. The switched reluctance motor drive system structure is simply introduced firstly in this paper, and then the research progress of it is summarized, including the switched reluctance motor design, the control strategy, the position detection technology and the vibration and noise. At the end of the paper, some attractive topics for further research are suggested.

Communication Mechanisms on the Virtual Functional Bus of AUTOSAR

With the rapid growth of automotive electronics, the application requirements increase greatly, the hardware abounds continuously, as a result, software system becomes more and more complex. For this reason, some major OEMs found Automotive Open System Architecture (AUTOSAR), now including a large number of automotive, electronics, semiconductor and software companies. AUTOSAR’s objectives are to implement and standardize basic system functions as an industry-wide standard core solution that offers scalability to different vehicle and platform variants. AUTOSAR defines the virtual functional bus (VFB) as a means for a virtual hardware and mapping independent system integration. VFB makes the integration process of automotive software can be done in much earlier design phases. AUTOSAR also specifies two kinds of communication mechanisms to fulfill different aims. This article gives an overview of the AUTOSAR initiatives and its goals. It describes the VFB concepts, highlights the communication mechanisms.

Survey of the AUTOSAR Complex Drivers in the Field of Automotive Electronics

The Complex Device Driver is a loosely coupled container, where specific software implementations can be placed. The only requirement to the software parts is that the interface to the AUTOSAR system has to be implemented according to the AUTOSAR port and interface specifications. The purpose of the Complex Device Drivers is to fulfill the special functional and timing requirements for handling complex sensors and actuators. It is used to handle the tasks related to the strict timing. The Complex Device Drivers are to some extend intended as a migration mechanism. If interfaces for extensions are defined according to the AUTOSAR standards new extensions can be implemented according to the AUTOSAR standards, which will not force the OEM nor the supplier to reengineer all existing applications.

Research on auto and rapid exchange system of EV battery cases

In order to solve the problem of short continuous driving mileage and long charging time of electric vehicle (EV), the method of auto and rapid exchange system of EV battery cases is proposed. The exchange system deals with corresponding control of multi-components which are relatively moving each other. Based on single chip wireless transceiver nRF905 and MC68HC908GZ16, the wireless communication module is designed. The controller single chip and the wireless transceiver is connected through SPI interface. Based on this module, the wireless communication control system is developed, which is used on battery cases quick exchange of EV. The system is made up of four wireless communication modules, which are portable device, machine arm, in-vehicular module and battery-case shelves module. The remote-control, quick localization, auto release are realized using this system. The parameters are calibrated through fieldwork. The system operates stably, reliably, and met application requirements of the project, which is verified by fieldwork.

The design of electric motor car's body network based on CAN-bus distributed control

CAN-bus is a typical bus control technology, and is now widely applied in many areas.In view of the characteristics of the electric vehicle body, this paper puts forward a plan that applies CAN-bus technology to build electric vehicle body network. In terms of the electric vehicle body system, it needs to resolve several issues: One is to simplify electronic wiring harness as far as possible, and the other is to ensure the normal data communications. In this article, the body electrical is divided into different nodes in accordance with the principles of proximity, each node controls a certain area of electrical equipment, and at the same time, communicates with other nodes through CAN bus. CAN bus used SAE1939 agreement and defined message through this agreement. Each body node of the circuit includes main circuit board and extended board. The main circuit can achieve the requirements of data communications; the extended board can achieve the expansion of body electrical. The circuits are divided into several modules in application with circuit modular design approach. Every module was respectively developed by embedded software system through some software development tools, at the same time, tested the entire body CAN network communications systems. After the test, the entire body of communications network can meet the requirements.

Strategy of Starting Sensorless BLDCM with Inductance Method and EMF Integration

In, conventional 3-stage start-up method of sensorless brushless direct current motor (BLDCM), the rotor is likely to jitter because rotor position cannot be obtained, and the motor is apt to lose step when it starts with load. These defects limit its use in engineering applications. In order to achieve smooth start in specific direction and guarantee start-up success rate with load, a start-up method based on improved inductance method and electromotive force (EMF) integration is proposed applying different voltage vectors according to rotor position interval judged by inductance method and determining integrator start-up time according to rotor initial position and the EMF. Experiments show that the method guarantees smooth acceleration and increases start-up success rate with load.

Analysis of schedulability of CAN based on RM algorithm

In order to analyze the schedulability of realtime transmission of multi-messages on controller area network (CAN), an amended scheduling algorithm is put forward. This algorithm is based on rate-monotonic (RM) scheduling algorithm, which is widely used on scheduling realtime multitasks on uniprocessor. CAN is treated as exclusive critical sections. The utilization of CAN is defined as a key factor of schedulability. A realistic workload of CAN in pure electric vehicle is present, and the schedulability of this system is calculated. The result is coincident to the actual work. The RM-scheduling upper limits of variant velocity messages are counted, which can be used as the guideline to evaluate the communication ability of CAN.

Design of BLDC Sensorless Control System for Vehicle Fuel Pump

This paper designs a kind of BLDC sensor less controll system for vehicle fuel pump. The control system uses 78F9222 of NEC as a core control unit, and uses the Back-EMF method to achieve the sensor less control for BLDC. The system can implement over-current protection, over voltage protection and over temperature protection. Loading test shows that the control system has high performance to meet the actual needs.