External motor drive system adjusting for creep in window covering system with continuous cord loop
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Window covering systems with internal motors face challenges in integrating user controls due to their internal configuration, and cord-type motor drive systems are prone to slipping and positioning errors caused by material fatigue or creep in continuous cord loops.
Innovation Solution
An external motor drive system with a continuous cord loop sensor system that maintains accurate automated positioning control by using sensors to detect and compensate for material fatigue or stretching, and includes on-device controls for user input and communication with other motor systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If an external motor drive system is used with continuous cord loop, then automated operation and on-device controls are enabled, but positioning accuracy deteriorates due to material fatigue or creep in the continuous cord loop
Solution Approach 1:
The patent employs feedback mechanisms where the motor controller continuously monitors the position of the window covering and adjusts motor operation to compensate for drift caused by cord loop creep. This closed-loop control system detects positioning errors and corrects them in real-time, maintaining accuracy despite material degradation over time.
Solution Approach 2:
The patent replaces purely mechanical positioning mechanisms with an electromechanical system that uses motor control and electronic feedback. Instead of relying solely on the mechanical integrity of the cord loop, the system uses electrical control with sensors and controllers to maintain positioning accuracy, substituting mechanical precision requirements with electronic control capabilities.
2Device complexity
If an internal motor system is used, then integration of drive components is simplified, but user control accessibility and device control integration become difficult
Solution Approach 1:
The patent segments the control system into separate functional modules: the motor drive unit remains integrated with the window covering mechanism for simplicity, while user controls are separated into independent on-device control elements that can be accessed directly on the motor housing. This segmentation allows the drive system to stay compact while providing accessible control interfaces.
Solution Approach 2:
The patent introduces an intermediary communication interface between the motor controller and user controls. The on-device controls serve as intermediaries that transmit user commands to the motor controller, enabling accessible control without requiring complex internal integration. This intermediary layer simplifies both the mechanical integration and user interface design.
Data Source
AI summary
A drive system for raising and lowering a window covering includes a motor, a driven wheel configured to engage a continuous cord loop, a controller for the motor, a sensor, and a housing. The continuous cord loop includes an endless loop of flexible material and one or more sensor targets disposed on the endless loop of flexible material. The housing supports a guide rail adjacent the driven wheel. The sensor is mounted to the guide rail and is configured to generate a signal indicating presence of each sensor target when the target is located in proximity to or in contact with the sensor. The controller is calibrated to store an initial position of each sensor target along the continuous cord loop, and is configured to receive the signal indicating presence of the sensor target and to identify a drift from the initial position during continuing operation of the drive system.