Steer By Wire Backup Clutch Torque Release Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the Steer By Wire (SBW) system, when the engine startup is delayed after the driver enters the vehicle, the backup clutch can become difficult to release, leading to a mismatch between the driver's intended steering state and the actual steering state, as the backup clutch is engaged, causing control issues with the turning motor.
Innovation Solution
The backup clutch is set to the engagement state when the engine starts, and switched to the release state when the detected steering torque is equal to or lower than a predefined clutch release start torque, with the turning motor providing assistance torque to align with the driver's steering operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the backup clutch is engaged during engine startup to suppress power consumption, then power consumption is reduced, but the clutch becomes difficult to release when the driver is steering, causing steering state mismatch
Solution Approach 1:
The system proactively monitors steering torque before clutch release is attempted, and only releases the clutch when steering torque falls below the threshold, preventing the harmful state of clutch engagement during active steering from occurring in the first place
Solution Approach 2:
The clutch release control unit continuously monitors steering torque as feedback and uses this information to determine the appropriate timing for clutch release, creating a closed-loop control system that adapts to the driver's steering actions
2Reliability
If the backup clutch is released frequently for diagnosis, then diagnostic accuracy is improved, but operation sound is generated during engagement and release
Solution Approach 1:
The system uses the driver's own steering operations as the trigger for clutch engagement and release, eliminating the need for separate diagnostic operations that would generate unwanted sounds
3Stability of the object's composition
If the engine startup is delayed after driver entry, then system stability is maintained, but the backup clutch remains engaged longer, increasing the risk of steering mismatch
Solution Approach 1:
The system continuously monitors steering torque as feedback and uses this real-time information to determine the optimal moment for clutch release, ensuring the clutch is released as soon as it becomes safe to do so, thereby minimizing the risk period while maintaining system stability during the waiting period
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A vehicle steering control apparatus and vehicle steering control method are provided, in which it is possible to suppress a steering state of a steering operation element from being different from the driver's intention, in starting the driving source. A backup clutch, which is switchable between a release state where a torque transmission path is mechanically decoupled and an engagement state where the torque transmission path is mechanically coupled, is set to the engagement state in starting the engine. When the steering torque detected after the engine starts becomes equal to or lower than a clutch release start torque Ts1, the backup clutch in the engagement state is switched to the release state. When the state of the backup clutch is set to the engagement state, a steering assistance torque of assisting the turning of the turning wheels is output from the turning motor for turning the turning wheels in response to the operation of a steering operation element. When the backup clutch in the engagement state is switched to the release state, the turning torque depending on a target turning angle in response to the operation of the steering operation element is output from the turning motor, so as to control driving of the turning motor.