Redundant Touchless HMI Inputs for Contamination-Safe Estop Control
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Solution Overview
Problem
Conventional human machine interfaces (HMIs) and emergency stop (Estop) switches in industrial automation systems require physical contact, which is undesirable in environments where contamination is a concern and can lead to increased costs and susceptibility to damage, and lack touchless input devices with redundant operation schemes.
Innovation Solution
The implementation of touchless input devices using first and second redundant touchless sensors, such as time-of-flight or electric field sensors, to detect hand gestures for providing input to industrial automation control systems without physical contact, allowing for redundant operation to prevent inadvertent actuation and ensuring safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If physical contact HMI devices are used, then ease of operation is maintained, but contamination risk and susceptibility to damage increase
Solution Approach 1:
The patent replaces mechanical contact-based input devices with touchless sensors that detect hand gestures through optical or electromagnetic fields. This substitution eliminates physical contact between the operator's hand and the HMI device, thereby preventing contamination while maintaining operational capability through gesture recognition.
Solution Approach 2:
The patent introduces an intermediary detection mechanism (touchless sensor) that mediates between the operator's intent and the system response. The sensor detects gestures through air or space without direct contact, acting as a mediator that translates physical gestures into digital signals without requiring tactile interaction.
2Reliability
If redundant mechanical contacts are used in Estop switches, then reliability is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces redundant mechanical contacts with a single touchless sensor that provides reliable emergency stop functionality through gesture detection. This eliminates the complexity of dual mechanical contacts, wiring, and associated components while maintaining safety through touchless operation that prevents contamination and mechanical failure.
Solution Approach 2:
The patent extracts the essential safety function from the complex mechanical contact system and implements it through a simplified touchless sensor. By taking out the core emergency stop capability and implementing it without mechanical contacts, the system achieves reliability with reduced complexity and eliminated redundant components.
3Reliability
If mechanical contacts are used, then redundant operation is achieved, but susceptibility to physical damage and contamination increases
Solution Approach 1:
The patent substitutes mechanical contacts with touchless sensors that have no moving parts or physical contact surfaces. This eliminates susceptibility to physical damage from liquid, dust, vapors, and corrosion while maintaining redundant operation capability through sensor-based detection that can provide multiple input states without mechanical wear.
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
The touchless HMI and Estop systems reduce the risk of contamination and physical damage, provide a cost-effective and safe solution by enabling non-contact input, and ensure reliable operation with redundant sensor arrangements.
Implementation Method 1
first and second touchless input sensors each configured to detect hand gestures of an operator's hand to provide input to said human machine interface based upon said gestures
Implementation Method 2
first and second touchless sensors to detect a first hand gesture
Data Source
AI summary
A human machine interface for an industrial automation control system includes at least one touchless input device that is adapted to be in a first state in which said human machine interface provides a first input to said industrial automation control system or a second state in which said human machine interface provides a second input to said industrial automation control system. The at least one touchless input device includes first and second touchless input sensors each configured to detect hand gestures of an operator's hand to provide input to said human machine interface based upon said gestures. The first and second touchless input sensors can be identical with respect to each other or different. In one example, one or both of the sensors are both time-of-flight sensors and one of the sensors can be an electric field proximity sensor. A method of providing a human machine interface with at least one touchless input device is provided. In one embodiment, the touchless input device provides an emergency stop (Estop) switch device.