Research On The Control System Of Chassis Dynamometer Based On The Embedded SCM

With a great boom of car industry, instruments and methods has gradually played avital role in intelligent inspection of vehicle performance. Automobile chassis dynamometeris an indoor roller type inspection instrument especially using to detect the performance ofengine power, acceleration, coast and fuel economy. To achieve the detection, it simulatesreal running conditions by flywheels and electronic dynamometer, the former simulatesvehicle inertia resistance and the latter simulates road resistance, and therefore it’s soimportant to ensure the reliability and accuracy of the detection result.This thesis is mainly engaged in the research on the control system of vehicle chassisdynamometer. Gathered the merits of high-performance, low power consumption and lowprice, the chip ARM is superior to other chips. Consequently, this thesis makes a research onthe control system building on current chassis dynamometer based on the ARM embeddedSCM.The following is the main research contents of this thesis.Firstly, it presents the structure and analyzes the working principle of chassisdynamometer and simulates the resistance on it. As the theory of constant speed controllingand constant torque controlling is alike except the detecting signal, a fuzzy-PID controllerand common PID controller is designed to adjust the input value of the dynamometerexcitation current, meanwhile, and a simulation experiment is made using simulink todemonstrate the accuracy of this controller and finally the constant speed controlling andconstant torque controlling is realized.Secondly, the hardware of the controlling system and the entire circuit diagram isdesigned centre on the chip ARM. It also demonstrates the fuzzy PID controller by Cprogram and separates the software into several modules to analyze and makes flowchartsabout them. To make the controlling system much consummate, the main interface and thecontrolling interface of each module is designed for the chassis dynamometer.Thirdly, to test the accuracy of the system, a program testing and whole car testing ismade. The program testing is about parts of the circuit centre on the chip ARM, especiallyabout the high speed pulse data acquisition. Moreover, based on the accurate model of fuzzy-PID built above, using the self-made circuit board and the ARM embeddeddevelopment board, a software program testing about the chassis dynamometer is made. Bycontrast and analyze the velocity and time data, the result about the practicability andreliability of the whole controlling system can be taken as a standard of judgment aboutwhether the design is up to the requirement of realizing the controlling function. The resultsshow that the system controlling with fuzzy-PID is better than common PID. Finally, themodel of this thesis is verified through theory and practical test.