Range Switchover Control System Motor Position Update
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Solution Overview
Problem
Conventional range switchover control systems in electric vehicles face delays and degraded driver feedback due to the inability to instantly stop or reverse the motor during range changes, leading to suboptimal response characteristics during shift range switching.
Innovation Solution
The system updates the target position of the motor based on the selected range change during rotational driving, allowing immediate switching to the new range if the rotation direction and position difference meet specific criteria, or waits until the previous range is completed if not, ensuring efficient and reliable range switchover.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the motor stop-and-hold processing is executed for a predetermined time period when the direction of rotation needs to be reversed, then the motor can be stopped and held at the target position, but the response characteristic of the range switchover lowers and shift feeling is degraded
Solution Approach 1:
The patent applies dynamics by making the control strategy adaptive based on real-time motor state. The ECU dynamically selects between immediate target position update and stop-and-hold processing based on whether the motor is rotating and the direction of rotation, thereby optimizing the balance between response speed and positioning accuracy under different operating conditions.
Solution Approach 2:
The patent changes the control parameter (target position) dynamically based on motor rotation state. When the motor is not rotating or rotation has stopped, the target position is immediately updated to the post-change target position, enabling faster response without compromising positioning accuracy when the motor is stationary.
2Speed
If the target position is updated immediately during motor rotation, then the range switchover response is faster, but the motor may not be stopped at the target position accurately
Solution Approach 1:
The control system dynamically adjusts the target position update timing based on motor rotation state. The ECU continuously monitors motor rotation and selectively updates the target position only when appropriate (when motor is not rotating or has stopped), ensuring both fast response when possible and accurate positioning when necessary.
Solution Approach 2:
The system uses feedback from the motor rotation state to control target position updates. The ECU monitors whether the motor is rotating and uses this feedback to determine whether to immediately update the target position or wait for the motor to stop, thereby maintaining both speed and accuracy requirements.
3Reliability
If the motor is driven to the pre-change target position and waited for completion before switching to post-change range, then the motor stops accurately at the target position, but the switchover takes more time and response characteristic lowers
Solution Approach 1:
The system prepares for potential target position changes by monitoring motor rotation state in advance. When the motor is not rotating or has stopped, the target position can be immediately updated, eliminating the need to wait for completion of previous switchover operations and improving overall efficiency while maintaining reliability.
Solution Approach 2:
The patent enables continuous range switchover operations by allowing target position updates to occur without waiting for previous operations to complete, as long as the motor is not rotating. This maintains continuous useful action and improves productivity while ensuring accurate positioning when the motor is stationary.
Data Source
AI summary
A SBW-ECU switches over a shift range to a selected range by rotationally driving a motor to a target position corresponding to the selected range. When a direction of rotation of the motor is the same as a direction toward the target position and a difference between the target position and a present position is larger than a threshold value in a case that the selected range is changed during rotational driving of the motor, the target position is updated to a post-change target position. When the direction of rotation of the motor is opposite to the direction toward the target position or the difference between the target position and the present position is smaller than the threshold value in the case that the selected range is changed during rotational driving of the motor, the target position is updated to the post-change target position after completing the switchover to the pre-change selected range.