Elevator Car Position Sensing via Time-of-Flight Air Path Measurement
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Solution Overview
Problem
Existing laser-based position reference systems for elevator cars are susceptible to atmospheric distortions such as temperature variations, air movement, humidity, and dust, leading to uncertainties in determining the absolute position of the elevator car.
Innovation Solution
A system using electromagnetic radiation transmitted via an air path with a detection device opposite the transmitting device, allowing for direct measurement of propagation time to determine the position of the elevator car, minimizing external influence effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a laser-based position reference system is used to determine the position of the elevator car, then the position can be determined, but the accuracy deteriorates due to atmospheric distortions such as temperature variations, air movement, humidity, and dust
Solution Approach 1:
The patent introduces an intermediary substance (gas or liquid) to fill the space between the transmitter and detector, replacing air as the transmission medium. This intermediary medium allows for more stable electromagnetic radiation propagation by eliminating atmospheric distortions caused by temperature variations, air movement, humidity, and dust, thereby maintaining measurement precision while overcoming the harmful environmental factors.
2Ease of operation
If electromagnetic radiation is transmitted via air path for position measurement, then the system can operate remotely, but the measurement reliability deteriorates due to external influences on the laser beam quality
Solution Approach 1:
The patent creates an inert environment by filling the transmission path with a controlled gas or liquid medium that is resistant to atmospheric distortions. This inert atmosphere stabilizes the electromagnetic radiation propagation, ensuring consistent beam quality and reliable measurements while maintaining the remote operation capability of the system.
3Illumination intensity
If the laser beam intensity is increased to compensate for atmospheric losses, then the signal strength improves, but the system complexity increases due to additional compensation mechanisms
Solution Approach 1:
The patent changes the physical parameter of the transmission medium from air to a controlled gas or liquid environment. This parameter change fundamentally alters the propagation characteristics, allowing for stable signal transmission without requiring intensive beam intensity compensation mechanisms, thereby maintaining system simplicity while ensuring reliable operation.
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
Provides accurate and reliable determination of the elevator car's position with reduced dependence on external factors, adaptable to existing elevator systems with minimal installation effort.
Implementation Method 1
The transmitting device is configured to transmit a measurement signal as electromagnetic radiation via an air path
Implementation Method 2
The detection device is configured to directly receive the measurement signal via the air path and to convert it into an electrical signal
Implementation Method 3
The processing device is configured to determine a propagation time of the measurement signal along the air path by means of the electrical signal
Data Source
AI summary
In an elevator system, a measurement system is provided in addition to an elevator car, an elevator controller and a transferring device configured to transfer electrical energy and/or information between the elevator car and the elevator controller. The measurement system has a transmitting device and a detection device which can be positioned separate and remote from the transmitting device by an air path. The detection device receives a measurement signal emitted from the transmitting device as electromagnetic radiation via the air path and converts it into an electrical signal. The transmitting device receives the electrical signal via the transferring device, determines a propagation time of the measurement signal over the air path by means of the electrical signal, and determines a distance (d) between the transmitting device and the elevator car by means of the propagation time.