Diagnosis methods for phase line faults of electric power steering system

Abstract

The invention discloses diagnosis methods for phase line faults of an electric power steering system. A diagnosis method for the phase line faults of a power motor in a power-on initiation state comprises the following steps: high frequency voltage supply, current collection, fault diagnosis, fault confirmation and fault treatment. A diagnosis method for judging the faults in a normal power stage comprises the following steps: collection of current signals and speed signals of the power motor, fault diagnosis, fault confirmation and fault treatment. The diagnosis methods for the phase line faults of the electric power steering system can fast detect the phase line faults of the electric power steering system and avoid conditions of locking and power chaos of the steering system.

Description

technical field [0001] The invention relates to an electric power steering system in the field of automotive electronics, in particular to a method for diagnosing a phase line fault of a power assist motor of the electric power steering system. Background technique [0002] EPS (Electric Power Steering) steering system is an automotive safety-related component, which has extremely high requirements on safety performance. to combine figure 1 As shown, the booster motor D1 is a permanent magnet synchronous motor driven by a three-phase inverter full bridge. When the phase-to-phase short-circuit or phase-line open-circuit fault occurs in the power booster motor D1, it may lead to high-risk events such as steering system lock-up and power boost confusion. [0003] Generally speaking, some motor driver chips provide the motor phase line short-circuit diagnosis function, but the short-circuit fault diagnosis function provided by the motor driver chip often has a relatively long ...

AI Technical Summary

Problems solved by technology

When the phase-to-phase short-circuit or phase-line open-circuit fault occurs in the booster motor D1, it may lead to high-risk events such as steering system lockup and power assist confusion, etc.

[0003] Generally speaking, some motor driver chips provide the motor phase line short-circuit diagnosis function, but the short-circuit fault diagnosis function provided by the motor driver chip often has a relatively long time delay. It does not provide the function of diagnosing the open circuit of the motor phase wire; and even if the motor driver chip can judge the fault, when a short circuit occurs between the motor phase wires, even if the motor drive circuit is turned off, due to the existence of the motor back EMF, the motor phase wire can A current is formed between the paths, which can still cause the steering system to lock

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