Wu Wenjiang

Study on Stability of Electric Power Steering System

The stability of the electric power steering system is analyzed on the basis of the mathematics model for pinion -and- rack steering system, the interference resistance is also studied by the way of fixing the steering wheel. The result shows that the stability of the system becomes poor gradually along with the increase of power ratio. The stability can be improved by PD control algorithm, but the influence on the system caused by the measure noise of torque sensor cannot be controlled. If PD combines with the Hinfin optimal control, the stability and interference resistance can be effectively improved.

Estimating algorithm of angular velocity on assisted motor

Angular velocity of assisted motor is the switch criteria for different control models of EPS. Reasonable estimation for angular velocity not only reduces the hardware configuration of EPS and decreases the hardware cost of the system, but also increases the reliability of the system. H∞ control theory was applied to angular velocity estimation of assisted motor. An H∞ filter was designed. The measurement noise from voltage sensor and current sensor was selected as exogenous disturbances. The estimated error for angular velocity was determined as adjusted output. The filter was simulated under simulink environment of MATLAB. The simulation result shows that the estimating algorithm is feasible.

A Networked Data Acquisition System Based on the MSC1210

In this paper, a new high precision A/D Converter MSC1210 which integrates 8052 Micro-controller and Flash Memory is presented at first. Then a networked data acquisition system based on the technology of Ethernet and RS-485 is designed. The communication between remote monitoring center and host computer is based on TCP/IP protocol through Ethernet, and the communication between host computer and numerous MSC1210s is based on RS-485 serial protocol. The system has characteristics of long-distance transmission, flexible configuration, good reliability and real-time performance. The scheme can be used in many fields, such as metallurgy, chemistry, colliery and etc, where remote data acquisition on large-scale system is needed.