Research And Design On The Algorithm And The Processing Circuit Of Flat Board Type Electromagnetic Induction Angle Sensor

Steering angle sensors have a big influence on the steering safety in the Electric Power Assisted Steering System and the Electronic Stability Program. With the increasing need of automobiles in China, it is of great importance for researchers to improve the reliability, durability and sensibility of steering angle sensors, since the safety of the steering is closely related to drivers' life safety. This paper studies a flat board type electromagnetic induction angle sensor, including the fundamental theory and structure, signal generation mechanism, angle algorithm and signal processing circuit. The angle sensor converts angle signals into electrical signals which contain the steering angle information by the electromagnetic coupling effect.In this paper, the value of the angle sensor in the steering system is brought forward by the introduction of the Electric Power Assisted Steering System and the Electronic Stability Program. Different non-contact angle sensors are compared with each other to summarize the achievement of international researchers on signal generation mechanism, angle algorithm and signal processing circuit. This paper chooses flat board type electromagnetic induction angle sensors to analyze three characteristics of the angle sensor. Firstly, signal generation mechanism is investigated by experiments on the basis of the theoretical research and analysis of theory and structure. Furthermore, it is found that output signals of the receiving coils have a regular pattern with the rotating angle. Secondly,based on the experiment results, a series of mathematic equations are obtained to build the linear angle algorithm which shows that the voltage peak values of the output signals correspond to the change of the steering angle. Finally, the signal processing circuit is divided into different units to design the hardware and the software in order to provide a reference of the flat board type electromagnetic induction angle sensor design and optimization.