Dual-Motor Steering Assist Control for Large-Inertia Response

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Solution Overview

Problem

Large inertia steering motors in vehicles are difficult to control quickly and efficiently, especially in larger vehicles, and their output is compromised during abnormal operations.

Innovation Solution

A power assist control system that includes a main motor and a sub-motor with a controller to manage their rotation speeds, allowing the sub-motor to assist the main motor in achieving target rotation speeds and supplementing output during reduced main motor performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a high-capacity steering motor is used to steer large vehicles, then the steering power is sufficient, but the inertia becomes very large making control difficult

Engineering Contradiction:

Improvesteering powerVSAvoidcontrol responsiveness

Core Design Contradiction:

PowerVSEase of operation

Solution Approach 1:

The steering motor is divided into two independent motors: a main motor providing high capacity steering power, and a sub-motor providing auxiliary steering power with smaller inertia. This segmentation allows each motor to have optimized characteristics for its specific function, resolving the contradiction between power and control responsiveness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The main motor and sub-motor are combined in a cooperative arrangement where both motors work together to provide the total steering torque. The sub-motor supplements the main motor during transient conditions, combining the high power of the main motor with the fast response of the sub-motor.

Inventive Principle:

Principle #5Merging (Combining)

2Ease of operation

If the main motor capacity is reduced, then control becomes easier, but the steering power becomes insufficient

Engineering Contradiction:

Improvecontrol responsivenessVSAvoidsteering power

Core Design Contradiction:

Ease of operationVSPower

Solution Approach 1:

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The control system dynamically adjusts the distribution of torque between the main motor and sub-motor based on real-time steering conditions. During transient steering maneuvers, the sub-motor provides additional torque to compensate for the reduced main motor capacity, ensuring sufficient steering power while maintaining control responsiveness.

Inventive Principle:

Principle #15Dynamics

3Power

If a single high-power motor is used, then steering power is sufficient, but control speed is slow due to large inertia

Engineering Contradiction:

Improvesteering powerVSAvoidcontrol speed

Core Design Contradiction:

PowerVSSpeed

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Inventive Principle:

Principle #15Dynamics

4Device complexity

If the main motor operates alone, then the system is simple, but output is insufficient during abnormal operations

Engineering Contradiction:

Improvesystem complexityVSAvoidoutput reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The sub-motor is positioned as a backup component that can compensate for main motor failures. This redundant configuration provides beforehand cushioning against potential main motor abnormalities, ensuring continued steering functionality even when the main motor operates abnormally or fails completely.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The control system can discard the faulty main motor from service and recover steering functionality using only the sub-motor. The system adapts by redistributing the steering torque requirement to the sub-motor alone, maintaining operational capability despite component failure.

Inventive Principle:

Principle #34Discarding and recovering

Data Source

PatentUS12139212B2Power assist control apparatus and power assist control method

Publication Date: 2024.11.12 HL MANDO CORP

AI summary

The present disclosure relates to a power assist control apparatus and a power assist control method. The power assist control apparatus according to the present disclosure comprises: a main motor driven at a first rotation speed; a sub-motor driven at a second rotation speed; and a controller which receives steering information from a steering wheel to calculate a target rotation speed value of an output shaft, and controls the main motor and the sub-motor such that the output shaft is rotated at the target rotation speed.