Steering Device Phase Control for Rough Road Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Steered wheels become unstable and steering performance deteriorates due to reverse inputs from rough road surfaces, such as gravel or unpaved roads, in existing electric power steering devices.
Innovation Solution
A steering device with a controller that compares the phases of motor rotation-angle and steering angle signals to determine if a reverse input state is present, and outputs a command signal to suppress movement of the steering mechanism when a reverse input is detected, using an electric motor, speed reducer, and sensors to stabilize the wheels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the electric motor applies steering force to the steering mechanism, then steering assist is provided, but the steered wheels become unstable when reverse input occurs from rough road surfaces
Solution Approach 1:
The controller continuously monitors the phase relationship between motor rotation-angle signal and steering angle signal, detecting reverse input conditions in real-time. When reverse input is detected (steering angle signal phase ahead of motor rotation-angle signal phase), the controller automatically adjusts motor output to suppress unwanted steering mechanism movement, providing feedback-based stabilization while maintaining steering assist functionality
Solution Approach 2:
The system dynamically adjusts motor control based on operating conditions by comparing signal phases. The controller switches between normal steering assist mode and reverse input suppression mode depending on the phase relationship detected, making the steering system adaptable to different road conditions while maintaining both assist performance and stability
2Adaptability or versatility
If the steering mechanism responds to reverse input from the road surface, then the steered wheels move, but steering performance deteriorates
Solution Approach 1:
The phase comparison between motor rotation-angle signal and steering angle signal provides continuous feedback about the steering system's response to road inputs. This feedback enables the controller to distinguish between driver-initiated steering and reverse input from rough roads, allowing selective suppression of performance-deteriorating movements while maintaining responsiveness to legitimate steering demands
Data Source
AI summary
An electric motor is controlled so as to suppress movement of a steering mechanism in response to a reverse input from a road surface during travel on rough roads, for example, a gravel road or an unpaved road.