Window Lifter Control Device Anti-Trap Protection
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Solution Overview
Problem
Current power-operated window lifters in vehicles, especially in convertibles and those with oblique window frames, often fail to provide adequate anti-trap protection, leading to potential injuries due to malfunctioning operating elements and loss of closing force limitation, resulting in an increased risk of trapping during automatic closing.
Innovation Solution
A control device that determines the functionality of anti-trap protection and adjusts the window lifter's movement speed and actuation sequence to ensure safety, reducing the risk of trapping by moving the window at a lower speed when protection is not guaranteed and requiring multiple actuations or specific sequences to initiate movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If automatic closing mode is provided with anti-trap protection, then safety against trapping is improved, but device complexity increases due to additional sensors and control mechanisms
Solution Approach 1:
The control device continuously monitors the drive torque during window closing operations and compares it against predetermined thresholds. When the torque exceeds the threshold, the system automatically reverses the window movement, providing real-time feedback-based safety without requiring additional mechanical sensors in the window mechanism itself.
Solution Approach 2:
The system uses the existing motor and control unit to perform both the closing function and the anti-trap protection function. The control device determines whether anti-trap protection is guaranteed based on the current operating conditions and automatically adjusts its behavior, making the system self-monitoring and self-regulating without external intervention.
2Reliability
If closing force limitation is implemented, then protection against trapping is improved, but the ability to close windows in all vehicle configurations deteriorates
Solution Approach 1:
The control device dynamically adjusts its operation mode based on real-time conditions. When anti-trap protection is determined to be guaranteed, the system enables automatic closing mode with full closing force limitation. When protection cannot be guaranteed (as in certain convertible or oblique frame configurations), the system automatically switches to manual closing mode, adapting its functionality to the specific vehicle configuration without requiring hardware modifications.
Solution Approach 2:
The system changes the operational parameters of the window lifter based on the determined safety conditions. The control device modifies the actuation requirements and movement characteristics according to whether anti-trap protection is available, allowing the same hardware to operate safely across different vehicle types by changing control parameters rather than physical structure.
3Ease of operation
If manual closing mode is used without anti-trap protection, then ease of operation is improved, but safety against trapping deteriorates
Solution Approach 1:
The control device implements preliminary safety checks before enabling manual closing mode. When anti-trap protection cannot be guaranteed, the system preemptively requires a specific actuation sequence (first actuation stage followed by second actuation stage) to initiate closing. This preliminary action ensures that even in manual mode, the operator's intent is confirmed, reducing the risk of accidental closing while maintaining ease of operation for intentional closing actions.
4Reliability
If actuation sequence requirements are added when anti-trap protection is not guaranteed, then safety is improved, but ease of operation deteriorates
Solution Approach 1:
The system applies a more stringent actuation requirement (two-stage actuation sequence) only partially - specifically when anti-trap protection cannot be guaranteed. When protection is available, the system accepts simpler actuation inputs. This partial application of excessive action maintains ease of operation for the majority of safe operating conditions while providing enhanced safety checks only when necessary, minimizing the impact on overall usability.
Data Source
AI summary
The invention relates to a control device for controlling an externally-powered window lifter with anti-trap protection for a motor vehicle window. A control device of this type is designed to determine that an operating element for closing the window is actuated and, in response thereto, the window is moved in the closing direction. The control device is further designed to determine that the functional activity of the anti-trap protection is no longer guaranteed. In the case of a control device and in the event that it has been determined that the functional activity of the anti-trap protection is not guaranteed, the window lifter is actuated in response to the actuation of the operating element in such a way that the window is moved at a lower displacement speed in the closing direction when compared with the displacement speed with guaranteed functionality. In the case of an alternative control device and in the event that it has been determined that the functional activity of the anti-trap protection is not guaranteed, the window lifter is actuated in response to the actuation of the operating element with a predetermined actuation sequence of the window lifters in such a way that the window is displaced in the closing direction starting from the idle state.