Building Closure Motor Current Control for Position Stability
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Solution Overview
Problem
Existing building closure systems, such as overhead sectional doors, face challenges in maintaining precise open positions due to varying torsion spring forces and require additional security measures to prevent unauthorized opening, often involving costly solutions like auxiliary windings or mechanical interlocking units.
Innovation Solution
A method utilizing a control apparatus that adapts to the door's parameters, incorporating a position detection unit and residual energizing of the drive device to maintain equilibrium forces and prevent unauthorized opening, achieved through programmable control of motor current along the travel path and in terminal positions, using techniques like pulse-width modulation or phase angle control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the door is opened to maximum position to have entire passage opening available, then the passage opening area is improved, but the torsion spring counteracts the strongest force which may result in failure to achieve maximum opening width
Solution Approach 1:
The motor is dynamically controlled to provide variable torque along the door travel path. The control apparatus adjusts motor current based on position feedback, increasing torque output when the door approaches terminal positions where torsion spring counterforce is maximum, enabling the door to overcome the strongest counteracting force and achieve full opening area
Solution Approach 2:
A position detection unit provides real-time feedback on door position to the control apparatus. This feedback enables the control system to monitor door movement and adjust motor current dynamically, ensuring sufficient force is applied at terminal positions to overcome torsion spring counterforce and maintain precise positioning at maximum opening
2Reliability
If a self-locking gear device is used to prevent unauthorized opening, then the security is improved, but the self-locking device can be overcome when applying sufficient force
Solution Approach 1:
The patent replaces mechanical self-locking gear devices with an electrical control system. The motor with residual energizing capability creates an electrical barrier that actively resists unauthorized opening forces, making the system more reliable than passive mechanical locks that can be overcome with sufficient force
3Reliability
If residual energizing is applied to maintain door position and prevent forced opening, then the reliability is improved, but heat generation increases
Solution Approach 1:
Instead of continuous full energizing, the system uses periodic or pulsed residual energizing controlled by the control apparatus. The motor receives intermittent current pulses sufficient to maintain position against torsion spring force and resist unauthorized opening, reducing overall heat generation while maintaining reliability
Solution Approach 2:
The control apparatus dynamically adjusts motor current parameters based on door position and external forces. Residual energizing current is optimized to provide just enough force to maintain position stability and prevent forced opening, minimizing excessive current and associated heat generation
4Reliability
If expensive solutions like auxiliary winding or mechanical interlocking units are used, then the security and position maintenance are improved, but the device complexity and cost increase
Solution Approach 1:
The motor serves multiple functions: it provides door movement force, maintains door position through residual energizing, and prevents unauthorized opening. The control apparatus integrates position detection, torque control, and security functions into a single system, eliminating the need for separate auxiliary windings or mechanical interlocking units while maintaining reliability
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 solution reliably maintains the door in both open and closed positions, preventing accidental or forced openings while minimizing costs and heat generation, and adapts to parameter changes, ensuring consistent operation despite aging or modifications.
Implementation Method 1
energizing the drive device is not suspended by at least one program or by program steps, instead residual energizing of the control apparatus is maintained. This amount of residual current generates a counteracting force
Implementation Method 2
Based on the provided reference information, and in conjunction with a position detection unit, it is possible to always determine the exact position of the door leaf
Data Source
AI summary
A method for operating a building closure having the shape of an overhead sectional door or of a garage door including at least one spring-loaded counterweight device and an electrical drive device is disclosed. A control unit simultaneously monitors the position of the building closure and a motor current for the drive device. When the building closure is in an open or a closed position, the motor current is reduced and maintained at a level to residually energize the drive device to reliably maintain the building closure in a desired position.