Study On Torque And Angle Sensor Of Electric Power Steering

The automobile market is the biggest one in the market of sensors. The sensors are playing an important role in the modernized system of the car at the same time. With the improvement of the demand for the safe, energy-saving and environment-protective car of the society, electronic power steering (EPS) and the electronic stability program (ESP) and other intelligent control systems are equipped in more cars. The effective operation of these cars of automatically controlled systems, not merely need turning to the torsion signal, and need to turn to the angle signal. At present the torque sensors of EPS or steering angle sensors ESP is two kinds of independent ones and employ the sensing device of different principles. This paper research an installation, which is a non-contact type steering sensor fixed on steering column, it integrates the torque and angle measurement. Through the innovative research of signal transformation method and the design of the device for the signal transform, integrate the torque/ steering angle as one sensor, realize the torque / steering angle simultaneous measurement.The paper has introduced various torque sensors used in the EPS at present. Compare and analyze the pluses and minuses of all kinds of torque sensors synthetically. Proposing a new kind of non-contact type torque / steering angle sensor. The mechanical structure of the key part of this sensor is designed in this paper. Adopt the magnetic resistance (MR) as the sensitive element, combine certain amplify circuit and filter circuit, use the angle phase difference process chip named UZZ9000. Hardware circuits including of signal processing are designed employing EDA tool Cadence. Matlab software is used to prove the torque /steering sensor's system function. Obtain the relationship between torque and steering angle. Simulink toolbox in Matlab carries on emulation to the whole sensor and signal processing system, producing the simulation wave. Combining the simulation wave, analyze that obtain the relation between the torque and the steering angles.The key research of this paper is non-contact type signal obtained way, including of torque signal to magnetic electric signal, steering angle signal to magnetic electric. The signal transform device structure, the signal process circuit, match relationship between sensor signal and EPS electric controlled unit and characteristic of sensor, etc. Integrating the torque and angle signal of a sensor to measure is one of innovation points. It can reduce the quantity of sensor but can offer automobile other intellectual unit steering angle signal. Another innovation point is lighted to process the angle special-purposely the chip UZZ9000 is used in the sensor of the torque. It makes the separation component of the circuit reduce greatly. Thus the signal of the whole sensor process circuit is simplified.