Range-switching Control Device for Shift Range Delay
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing range-switching control systems in vehicles may experience delayed switching completion times, leading to potential safety issues as drivers may misunderstand the inability to change gear, prompting them to exit the vehicle prematurely.
Innovation Solution
A range-switching control device with a delay-determination portion to detect delayed switching completion times, a change-determination portion to assess the need for a safer gear range, and a target-range-change portion to switch to a safer range, such as the parking range, ensuring safety without altering the target range when unnecessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the motor is driven to the target rotational position using feedback control based on encoder pulse signals, then the shift range switching accuracy is improved, but the switching completion time may be delayed when feedback control fails and open loop control is used
Solution Approach 1:
The system performs preliminary assessment of driver alighting conditions before finalizing the shift range switching action. When delay is detected, the control portion evaluates whether the driver is likely to alight based on timing and condition thresholds, and only proceeds with the switching action if safety conditions are met, preventing premature driver exit due to perceived system failure
Solution Approach 2:
The system continuously monitors the switching completion time and compares it against expected time thresholds. When the actual switching time exceeds the threshold indicating feedback control failure, the system activates open loop control while simultaneously assessing driver behavior patterns to determine appropriate safety responses, creating a feedback loop that adapts control strategy based on real-time performance
2Reliability
If the target range is changed to a safer range when switching delay is detected, then driver safety is improved, but the normal shift range switching functionality is compromised
Solution Approach 1:
The system applies different control strategies to different aspects of the shifting operation. When delay is detected, it selectively modifies only the target range determination logic based on driver alighting probability, while maintaining normal motor control execution. This localized modification ensures safety without disrupting overall system functionality
Solution Approach 2:
The control portion dynamically changes the target range parameter based on detected switching delays and assessed driver conditions. When the driver is determined to be at risk of alighting due to perceived system failure, the system adjusts the target range to a safer alternative (e.g., from drive range to neutral or park), thereby changing operational parameters to prioritize safety while maintaining system functionality
Data Source
AI summary
During changing of a shift range (for example, from P-range to NotP-range), an SBW-ECU determines whether it is in a range-change delay condition (a switching completion time of the shift range is delayed than a normal switching completion time). When it is determined that it is in the range-change delay condition, it is determined whether a target range should be changed to a safer range (for example, P-range). As a result, when it is determined that the target range should be changed to the safer range, the target range is changed to the safer range. Thereby, even if a driver determines that the shift range cannot be changed before the switching completion of the shift range and the driver gets off the vehicle, the shift range can be changed to the safer range (P-range).