Elevator Speed Detection Using Hybrid Altimeter Pressure Gradient
Solution Overview
Problem
Contemporary elevator systems face issues with accelerometer offset errors leading to velocity calculation drift over time, affecting accuracy and reliability in determining the speed of moving objects within hoistways.
Innovation Solution
An electronic speed detection system that incorporates a hybrid altimeter comprising a first pressure sensor coupled to the moving object and multiple second pressure sensors at fixed locations, along with a controller to determine a normalized position and correct velocity using atmospheric pressure differences, thereby addressing accelerometer offset errors and monitoring potential over-speed conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If an accelerometer is used to determine velocity, then velocity can be calculated from acceleration data, but the velocity calculations drift over time due to accelerometer offset errors
Solution Approach 1:
The system uses pressure sensors to provide feedback on the actual position of the elevator car, which is then used to correct the integrated acceleration data. The controller continuously compares the position derived from pressure sensors with the position calculated from accelerometer integration, and applies correction factors to eliminate drift accumulation.
Solution Approach 2:
Pressure sensors serve as an intermediary measurement system that provides an independent reference for position and velocity. Instead of relying solely on the accelerometer, the system introduces pressure-based altitude measurement as a mediator to verify and correct the accelerometer-derived velocity, thereby eliminating offset errors.
2Measurement precision
If multiple pressure sensors are deployed at fixed locations, then position measurement accuracy improves, but system complexity increases
Solution Approach 1:
The hoistway is segmented into multiple discrete measurement zones, each equipped with a pressure sensor. By dividing the measurement space into segments and placing sensors at specific locations, the system achieves high position measurement accuracy through localized pressure differential measurements without requiring a continuous complex sensing system.
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 system provides accurate and stable velocity determination by correcting accelerometer offset errors, enhancing the reliability of speed monitoring and reducing the risk of over-speed conditions in elevator systems.
Implementation Method 1
a hybrid altimeter comprising a first pressure sensor coupled to the moving object and a plurality of second pressure sensors, each of said plurality of second pressure sensors at a separate fixed location within the hoistway, and each of the plurality of second pressure sensors providing atmospheric pressures corresponding to those separate fixed locations
Implementation Method 2
a second input received from the accelerometer
Data Source
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AI summary
An electronic speed detection system is provided. The electronic speed detection system includes an accelerometer coupled to a moving object and a hybrid altimeter, which includes a first pressure sensor coupled to the moving object and a second pressure sensor. The electronic speed detection system also includes a controller comprising a memory and a processor. The memory storing computer program instructions executable by the processor to cause the electronic speed detection system to determine a normalized position based on first inputs received from the hybrid altimeter, or determine a corrected velocity position based on a second input received from the accelerometer and the normalized position.