Motor Control System Obstruction Detection via Current Profiling
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Solution Overview
Problem
Conventional automatic door systems face challenges in integrating additional features due to the placement of obstruction detection switches, which limits their functionality, especially in fire safety applications where detecting obstructions is crucial.
Innovation Solution
A motor control system comprising a motor control circuit, a processing circuit, and a current sensor that generates an operation profile and threshold profile to monitor current values, allowing for real-time detection of anomalies such as obstructions by comparing subsequent current values to the threshold, thereby dynamically adjusting and stopping the door if excessive current is detected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a switch or actuator is placed in the lead post for detecting obstructions, then obstruction detection capability is improved, but the ability to integrate other features in the lead post area deteriorates
Solution Approach 1:
The patent extracts the obstruction detection function from the mechanical switch/actuator in the lead post and relocates it to a processing circuit that monitors current consumption of the motor. This allows the lead post area to be freed for other features while maintaining obstruction detection capability through electrical monitoring instead of mechanical sensing.
Solution Approach 2:
The patent replaces the mechanical switch or actuator system with an electrical current monitoring system. The processing circuit analyzes current consumption patterns to detect obstructions, substituting mechanical detection with electrical field-based detection, thereby eliminating the need for physical components in the lead post.
2Reliability
If conventional current-based over current protection is used, then motor protection is improved, but the ability to detect specific anomalies such as obstructions deteriorates
Solution Approach 1:
The patent performs preliminary characterization of the motor's current consumption profile under normal operating conditions. By establishing a baseline current profile that varies with door position and operating state, the system can later compare actual current consumption against this profile to detect anomalies such as obstructions, distinguishing them from normal high-current states like door closing.
Solution Approach 2:
The patent implements a feedback mechanism where the processing circuit continuously monitors motor current consumption and compares it against the stored current profile. When deviations exceeding a threshold are detected, the system provides feedback to determine abnormal conditions and can trigger appropriate responses, enabling precise anomaly detection while maintaining motor protection.
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
Enables effective detection of obstructions during door operation, ensuring safe operation and integration of additional features without compromising existing functionality, enhancing security and fire safety measures.
Implementation Method 1
A current sensor may be operably coupled to the processing circuitry and configured to sense a current delivered to the motor control circuit from a power source. The current sensor may convey a signal to the processing circuitry proportional to the amount of current sensed.
Data Source
AI summary
Motor control systems comprise a motor control circuit, a processing circuit operably coupled to the motor control circuit, and a current sensor operably coupled to the processing circuit. The current sensor may be configured to sense a current and to convey a signal to the processing circuitry proportional to an amount of current sensed. The processing circuitry may be configured to sample the signal to obtain a plurality of current values, to store the plurality of current values and to generate an operation profile from the plurality of current values. Folding partitions comprising motor control systems are also disclosed, as well as methods of monitoring an operation of an electric motor and of monitoring for an obstruction of a folding partition.