Automotive Electric Power Steering System

Abstract

The invention discloses an automobile electric power steering (EPS) system. The EPS system comprises a motor winding temperature on-line estimation module and a control parameter self-adjusting function module, wherein the motor winding temperature on-line estimation module is used for acquiring the current and the environmental temperature of a motor and estimating the winding temperature and the winding resistance of the motor; and the control parameter self-adjusting function module is used for real-timely adjusting the flux weakening parameter, the d-axis PI control parameter and the q-axis PI control parameter in the motor control algorithm according to the estimated winding temperature and winding resistance of the motor, power assisting moment directive value of the motor, current of the motor, rotational speed of the motor and angle of the motor. The automobile EPS system can achieve on-line estimation of the winding temperature of the motor, realizes self-adjustment of the control parameter, and reduces the control torque fluctuation of the motor under different use conditions.

Description

technical field [0001] The invention relates to an automobile electric power steering system (EPS), in particular to an electric power steering system with functions of online estimation of motor winding temperature and self-adjustment of control parameters. Background technique [0002] The EPS steering system is an automotive safety-related component, which has extremely high requirements on the torque ripple performance of the motor control. The booster motor is a permanent magnet synchronous motor driven by a three-phase inverter full bridge. In a high-power electric power steering system, a permanent magnet synchronous motor is generally used as the actuator for power assistance. The core control algorithm of the permanent magnet synchronous motor includes field weakening control and PI (proportional integral) control of the d and q axes. In the conventional control method, the parameters of field weakening control, d-axis and q-axis PI control are generally fixed. Ho...

AI Technical Summary

Problems solved by technology

However, during the operation of the actual electric power steering system, the temperature of the motor will increase, so the internal resistance of the motor will change

In the case of changes in the internal resistance of the motor, the same field-weakening control parameters and PI control parameters will cause the torque ripple of the motor control to increase, thereby affecting the driver's hand feeling

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