Window Actuator Obstacle Detection via Segmented Force Thresholds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing window systems with pivotable sashes face challenges in reliable pinch detection and varying force requirements due to different window sizes, installation conditions, and environmental factors, making it difficult to ensure safe and efficient closure while preventing injuries.
Innovation Solution
An electrically operated actuator that monitors the closing force and initiates reversing operations when a threshold is exceeded, allowing trapped objects to be removed before applying a higher closing force, with adaptable thresholds based on motor speed and sash position to ensure safe and complete closure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a high closing force threshold is used to ensure proper window closure under various conditions (wind, snow, friction), then the window can close reliably, but the risk of pinching or entrapment injury increases
Solution Approach 1:
The closing operation is segmented into multiple phases with different force thresholds: a first closing operation with a lower threshold for safety, and a second closing operation with a higher threshold for reliable closure. This segmentation allows the system to balance safety and reliability by applying appropriate force levels at different stages of the closing process.
Solution Approach 2:
The actuator performs periodic closing operations with alternating force levels. The system executes a first closing operation at a lower force threshold, then a second closing operation at a higher force threshold. This periodic alternation between safe and effective closing forces ensures both injury prevention and reliable window closure.
2Object-affected harmful factors
If a low closing force threshold is used to prevent pinching injury, then safety is improved, but the window may fail to close properly under high friction or wind conditions
Solution Approach 1:
The closing operation is divided into sequential phases: a first closing operation with a lower force threshold to ensure safety, followed by a second closing operation with a higher force threshold to ensure complete and reliable closure. This segmentation resolves the contradiction by applying appropriate force levels at different stages.
Solution Approach 2:
The first closing operation with the lower force threshold serves as a preliminary action that safely moves the window sash most of the way closed while monitoring for obstructions. This preliminary safe closing allows the system to then apply higher force in the second operation to complete the closure reliably, without risking injury during the high-force phase.
3Productivity
If the actuator applies force continuously to close the window quickly, then productivity is improved, but false pinching signals may occur due to wind or external factors
Solution Approach 1:
The actuator performs periodic closing operations with alternating force levels. By executing a first closing operation at a lower force threshold and then a second closing operation at a higher force threshold, the system maintains productivity while improving detection reliability. The periodic nature allows the system to distinguish between normal resistance variations and actual pinching events.
Solution Approach 2:
The actuator continuously monitors the closing force during each operation and compares it against the threshold. This feedback mechanism allows the system to detect when the threshold is exceeded and initiate a reversing operation, thereby distinguishing between normal resistance (wind, friction) and actual pinching events, improving detection accuracy while maintaining productivity.
4Object-affected harmful factors
If the actuator reverses immediately upon threshold exceedance, then safety is improved, but the closing operation may be terminated due to false pinching signals
Solution Approach 1:
The closing process is segmented into a first closing operation with a lower threshold and a second closing operation with a higher threshold. By reversing only when the threshold is exceeded during the first operation, the system ensures safety without prematurely terminating the closing process, as the second operation can still complete the closure with higher force tolerance.
Solution Approach 2:
The first closing operation with the lower threshold serves as a preliminary safety check. If an obstruction is detected, the actuator reverses to prevent injury. If no obstruction is detected, the closing operation can proceed to the second phase with higher force, ensuring complete closure without false terminations.
5Reliability
If multiple closing operations with threshold monitoring are implemented, then pinch detection reliability is improved, but the closing time increases
Solution Approach 1:
The closing operation is segmented into two distinct phases with different force thresholds. The first phase uses a lower threshold for safety monitoring, and the second phase uses a higher threshold for complete closure. This segmentation improves pinch detection reliability while minimizing time loss, as each phase is optimized for its specific purpose.
Solution Approach 2:
The actuator performs periodic closing operations with alternating force levels. The first closing operation at a lower force threshold and the second closing operation at a higher force threshold are executed in sequence. This periodic approach improves detection reliability while maintaining efficient closing time by quickly alternating between the two force levels.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively detects pinching events, reduces the risk of injury by allowing trapped objects to escape, and ensures proper window closure while adapting to changing conditions, avoiding false signals from wind or other external factors.
Implementation Method 1
monitoring an indicator of a closing force applied onto the sash by the actuator
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
An electrically operated actuator (10) for operating a window (1), the window comprising a frame (2) and a sash (3) being pivotally suspended from the frame (2) by a horizontal pivot axis. The actuator (10) is adapted to perform a first closing operation (101) while monitoring an indicator of a closing force applied onto the sash (3) by the actuator (10). The actuator is adapted to initiate a first reversing operation (102) upon the indicator of closing force exceeding a threshold during the first closing operation (101), and the actuator (10) is configured to initiate a subsequent, second closing operation (104) after the first reversing operation (102). The threshold is selected from a plurality of predetermined thresholds.