Steering Drive Actuator Segmentation and Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional 'steer-by-wire' steering drives for vehicles require complex mechanical designs and significant space due to direct mechanical connections between servomotors, and they fail to ensure safe drivability when a servomotor malfunctions, as the affected wheel does not maintain the target steering angle.
Innovation Solution
A simplified steering drive design where each servomotor is directly connected to a wheel without a mechanical connection between them during normal operation, and includes means to position a malfunctioning servomotor to a target angle (e.g., 0°) using mechanical or electrical means, ensuring the wheel can be locked in place for safe steering corrections, and allowing all-wheel steering with individual servomotor control for enhanced safety and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If direct mechanical connection between two wheels via actuating element is provided, then the two actuators are coupled to each other, but the mechanical complexity and space requirement increase
Solution Approach 1:
The steering system is divided into two independent steering circuits, each controlling one wheel independently. This segmentation eliminates the need for mechanical coupling between actuators while maintaining the ability to coordinate wheel positions electronically, thereby reducing mechanical complexity without sacrificing reliability
Solution Approach 2:
The mechanical coupling between actuators via actuating element is replaced by electronic control through the control unit. The control unit coordinates the two independent actuators based on steering input and wheel position feedback, achieving the same coupling effect without mechanical connections, thus reducing device complexity and space requirements
2Reliability
If direct mechanical connection between two wheels via actuating element is provided, then the actuators are coupled, but the space requirement increases
Solution Approach 1:
By segmenting the steering system into independent circuits for each wheel, the patent eliminates the need for a shared actuating element and mechanical coupling structure. Each actuator operates independently with its own control circuit, significantly reducing the space required for mechanical components while maintaining system reliability through electronic coordination
Solution Approach 2:
The mechanical actuating element that physically couples the two actuators is replaced by an electronic control system. The control unit communicates steering commands and position feedback between the two independent actuators electronically, eliminating the need for mechanical coupling structures and thereby reducing the overall space requirement of the steering system
3Volume of moving object
If no mechanical connection is provided between two wheels, then space is reduced, but safety during actuator malfunction is compromised
Solution Approach 1:
The patent incorporates a malfunction detection system that monitors the status of each actuator. When a malfunction is detected, the control unit activates compensatory control to position the affected wheel at a predetermined angle (typically straight ahead). This beforehand cushioning ensures safety during malfunction without requiring mechanical connections between wheels
Solution Approach 2:
The steering system incorporates feedback mechanisms that continuously monitor wheel positions and actuator status. When a malfunction is detected through feedback signals, the control unit adjusts the operation of the remaining functional actuator to compensate for the failed one, ensuring the vehicle can still be controlled safely. This feedback-based compensatory control maintains reliability without mechanical coupling between wheels
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a steering drive (10) for a vehicle (1; 1a), comprising a control arrangement (17) operable by a driver and two actuators (21, 22), each at least indirectly coupled to a wheel (11 to 14), wherein the connection of the control arrangement (17) to the actuators (21, 22) is without mechanical coupling. According to the invention, the steering drive (10) is designed such that, in normal operation, each of the two actuators (21, 22) is directly assigned to a wheel (11 to 14) and steers it, and that, in normal operation, no direct mechanical connection is formed between the two wheels (11 to 14) of an axle (15, 16).