Blind Drive Torque Detection via Motor Current
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Solution Overview
Problem
Existing actuator systems for winding screens struggle to anticipate and adapt to obstacles effectively, particularly due to complex configurations and limitations in accounting for the weight, size, and environmental conditions of the screen and guide rails, leading to potential untimely stopping and reduced performance.
Innovation Solution
A method that uses electronic means to detect torque changes and localized deformations in the screen, allowing for configurable detection thresholds to anticipate and prevent blocking situations, without relying on mechanical brakes, and incorporating digital signal processing to differentiate between normal operation and impending blockages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If mechanical or mechatronic devices (accelerometers, force sensors, contactors) are used to detect obstacles, then detection precision is improved, but device complexity increases
Solution Approach 1:
The patent replaces mechanical or mechatronic detection devices (accelerometers, force sensors, contactors) with an electronic control system that monitors motor supply current to detect obstacles. The control system analyzes current variations during screen movement to identify blocking situations, eliminating the need for additional mechanical sensors and reducing device complexity while maintaining detection capability
Solution Approach 2:
The motor's own supply current serves as the detection signal for obstacle detection. The control system utilizes existing current monitoring infrastructure to detect changes in electrical parameters that indicate screen blocking, allowing the system to self-diagnose without requiring separate detection mechanisms
2Manufacturing precision
If electromechanical devices with fixed parameters are used, then manufacturing precision is improved, but adaptability to different installation conditions deteriorates
Solution Approach 1:
The control system dynamically adapts obstacle detection parameters based on actual installation conditions. It adjusts detection thresholds and parameters according to screen weight, guide rail quality, and environmental factors, allowing the same device to optimize performance across different installation scenarios rather than requiring fixed mechanical parameters
Solution Approach 2:
The system changes operational parameters (current thresholds, detection sensitivity, timing) based on detected installation characteristics. By monitoring initial current draw and movement characteristics, the system automatically adjusts its detection parameters to match the specific installation conditions, achieving both precision and adaptability
3Reliability
If spring brakes are used to accompany winding shaft movements, then reliability is improved, but measurement precision of screen weight torque deteriorates
Solution Approach 1:
The patent extracts the obstacle detection function from the brake system. Instead of using spring brakes to provide both mechanical control and torque measurement, the solution separates these functions: the brake provides reliable mechanical control while the electronic control system independently detects obstacles through current monitoring, eliminating the interference between brake torque and screen weight torque measurements
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
This approach enhances the flexibility and precision of obstacle detection, allowing for earlier anticipation of blockages and improved responsiveness, while being cost-effective and adaptable to various installation conditions, reducing the risk of untimely stopping and improving daily operation of the screen.
Implementation Method 1
detecting a torque provided by an electric motor belonging to the actuator, this thanks to the monitoring of a supply current of this motor
Data Source
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AI summary
Said method makes it possible to control an actuator for winding a blackout screen around a winding shaft. Said actuator includes at least one electric motor. Said method includes: - at least one step a1 that involves using electronic means to detect (502) locking of the screen, during lowering or raising, by detecting a torque exerted by the motor on the winding shaft, said torque being determined on the basis of a current (I) for supplying power to the motor; and - a step a2 that involves stopping the motor when a signal representing the detected current is greater than a threshold current value (Iref). The electronic means are parametrizable. Moreover, said method includes at least one additional step b, used when the signal representing the detected current is less than the threshold current value (Iref) and involving detecting (514), on the basis of the detected current (I), a localized change in the shape of the screen, during lowering, by using the same electronic means.