Inductive Snap Hook Sensing for Reliable Anchor Connection Detection
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Solution Overview
Problem
Existing fall protection equipment lacks reliable and efficient methods to ensure workers are properly anchored to support structures, as conventional sensors may fail to detect non-ferrous metals and can be affected by environmental conditions.
Innovation Solution
The use of inductive sensors with LC resonant circuits, integrated into snap hooks or carabiners, which detect changes in resonant frequency to determine if a metal support structure is present and correctly anchored, providing reliable anchoring confirmation regardless of environmental conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional sensors are used to detect support structures, then the device can detect ferrous metals, but it fails to detect non-ferrous metals and is affected by environmental conditions
Solution Approach 1:
The patent replaces conventional magnetic sensors with inductive sensors that use electromagnetic induction principles. The inductive sensor includes a coil that generates an electromagnetic field, and when a metal support structure (ferrous or non-ferrous) enters the field, it induces eddy currents in the metal, which changes the electrical characteristics (impedance, resonant frequency) of the coil circuit. This substitution enables detection of both ferrous and non-ferrous metals reliably, overcoming the limitations of magnetic sensors that only detect ferrous metals.
Solution Approach 2:
The patent monitors changes in electrical parameters of the inductive sensor circuit, specifically impedance and resonant frequency, to detect the presence of metal support structures. When metal enters the electromagnetic field of the coil, the electrical characteristics of the coil change due to eddy current effects. By measuring these parameter changes, the system can reliably detect various metal types regardless of environmental conditions, solving both the reliability and versatility problems.
2Measurement precision
If inductive sensors with LC resonant circuits are used, then detection accuracy for non-ferrous metals improves, but device complexity increases
Solution Approach 1:
The patent integrates the inductive sensor coil directly into the body structure of the fall protection device, nesting the sensing element within the existing device architecture. The LC resonant circuit components are also integrated into the device's electronic control unit. This nesting approach minimizes additional space requirements and reduces overall device complexity while maintaining high detection precision for non-ferrous metals.
Solution Approach 2:
The inductive sensor circuit serves multiple functions: it detects the presence of metal support structures, determines the type of metal (ferrous or non-ferrous) through impedance analysis, and provides signals for the control unit to activate warning indicators. This multi-functionality reduces the need for separate detection systems, thereby limiting the increase in device complexity while achieving high measurement precision.
3Reliability
If multiple sensors and monitoring systems are integrated, then anchoring confirmation reliability improves, but ease of operation decreases
Solution Approach 1:
The fall protection device automatically performs sensor calibration and baseline establishment when activated. The control unit autonomously processes sensor signals, compares them against stored baseline values, and determines anchoring status without requiring user intervention. The system self-adjusts to environmental conditions and automatically updates its detection thresholds, maintaining high reliability while keeping operation simple for the user.
Solution Approach 2:
The control unit continuously monitors sensor outputs and provides real-time feedback through visual or audible indicators to confirm proper anchoring. When the sensor detects a metal support structure and confirms proper anchoring, the system provides a clear positive indication. If anchoring is improper or the sensor fails, the system provides warning signals. This automated feedback loop maintains high reliability while requiring minimal user interpretation or action.
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 ensures accurate detection of metal support structures, including non-ferrous materials, and maintains reliability even when covered by substances like concrete or ice, enhancing worker safety by ensuring proper anchoring.
Implementation Method 1
The inductive sensor includes an electrical circuit arranged within the body so that a resonant frequency of the electrical circuit of the inductive sensor changes when the support structure is within the area of attachment
Implementation Method 2
The inductive sensor is formed on a flexible printed circuit board that is flexed around the bowl of the body and the electrical circuit of the inductive sensor includes one or more capacitors connected in parallel with an inductor to form a LC resonant circuit, the LC resonant circuit being configured to exhibit a resonant frequency of at least 1 MHz when there is no metal in proximity to the circuit
Data Source
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AI summary
Techniques are described for monitoring and controlling fall protection equipment. For example, the techniques of this disclosure may be used to monitor the connection status of fall protection equipment, e.g., whether or not the fall protection equipment is connected to a support structure. The techniques described in the disclosure may determine whether the fall protection equipment is connected to a support structure based on changes in a resonant frequency of an electronic circuit of an inductive sensor within the fall protection equipment. The inductive sensor may be formed from sets of one or more coils, where a first set of one or more coils and a second set of one or more coils are wound in opposite directions.