Electric power steering device and control method thereof

Abstract

The invention provides an electric power steering device and a control method thereof. The device comprises a first motor used for providing steering assisting power corresponding to rotation of a steering wheel, the first motor is powered by two power sources, and each power source in the two power sources drives the first motor to generate one part of the steering assisting power; the device further comprises a second motor which is used for providing additional steering assisting power corresponding to rotation of the steering wheel when the first motor loses part of the steering assisting power, and the second motor is driven by one power source formed by coupling the two power sources so as to generate the additional steering assisting power. Therefore, when the electric power assisting device has a single-point fault and the first motor loses driving of one power source, the first motor can still provide 50% of steering assisting power, so that the second motor only needs to provide 25% of steering assisting power, and the electric power assisting device can continuously maintain 75% of steering assisting power output. Therefore, according to the technical scheme, the requirement of L4-level automatic driving for the redundant capacity of electric power steering can be met.

Description

technical field [0001] The present application relates to the technical field of vehicle engineering, in particular to an electric power steering device and a control method thereof. Background technique [0002] In the vehicle structure, the power transmission system from the steering wheel to the wheels is called the steering system. When the vehicle is moving, the steering system is used to maintain or change the direction of the vehicle. Nowadays, most vehicles use electric power steering systems. The traditional electric power steering system usually adopts a non-redundant design, that is, it only includes one electronic control unit ECU and one motor, and uses one power supply for power supply. When any node in the electric power steering system fails, the system can be shut down, and the steering force is completely provided manually. However, with the development of autonomous driving technology, especially the application of advanced driving assistant system (ADA...

AI Technical Summary

Problems solved by technology

However, some of the current redundant design schemes of electric power steering systems fail to meet the L4 level redundancy requirements, and some use complex drive circuits, multi-channel power supplies (4 and above) and complex control logic designs. , there are many faulty nodes and it is not conducive to the implementation

Images