Elevator Speed and Vibration Estimation via Hybrid FM-PPS Signal Model
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Solution Overview
Problem
Conventional methods for measuring the speed and vibration of an elevator car are inefficient and pose safety risks, with existing active ride control systems experiencing instability due to slow position feedback and uncontrolled acceleration.
Innovation Solution
A hybrid sinusoidal frequency modulated (FM) and polynomial phase signal (PPS) model is used to estimate the motion of an elevator car, allowing for improved speed and vibration measurement, even under stringent conditions with low frequencies and limited samples, by modeling dynamic motion and time-varying acceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a technician uses a hand-held tachometer to measure elevator car speed, then speed measurement is possible, but efficiency and accuracy are compromised due to the technician's difficulty in maintaining contact between the tachometer and guide rail while operating the inspection box
Solution Approach 1:
The system enables self-service measurement by using the elevator car's own motion to generate the measurement signal. The guide rail vibration sensor automatically detects speed and vibration parameters without requiring technician intervention, eliminating the need for manual tachometer operation while maintaining measurement accuracy.
2Measurement precision
If a technician climbs on top of the elevator cab to perform speed measurement, then speed information can be obtained, but serious safety concerns arise
Solution Approach 1:
The patent replaces the mechanical approach of physically mounting a tachometer on the moving cab with an automated sensor system. The guide rail vibration sensor remains stationary on the ground while measuring car motion through vibration analysis, eliminating all safety risks associated with technician exposure to moving equipment.
3Reliability
If an active ride control system uses position feedback control to suppress vibrations, then ride quality can be improved, but the controller becomes slow and the output is limited to prevent actuator overheating
Solution Approach 1:
The system performs preliminary measurement and analysis of guide rail vibrations before control action is needed. By continuously monitoring vibration characteristics and predicting resonance conditions, the system can prepare appropriate control responses in advance, enabling faster reaction times while preventing actuator overload through proactive parameter adjustment.
4Reliability
If the acceleration controller output is not restricted to provide strong vibration suppression, then large amplitude resonance forces are produced at the actuators causing closed loop controllers to become unstable
Solution Approach 1:
The system implements feedback control by continuously monitoring guide rail vibration signals and adjusting actuator commands in real-time. The feedback mechanism detects resonance conditions and automatically modulates the control output to maintain stability, preventing actuator saturation while achieving effective vibration suppression through adaptive gain adjustment.
Data Source
AI summary
Systems and methods for an elevator. The elevator includes an elevator car to move along a first direction. A transmitter for transmitting a signal having a waveform. A receiver for receiving the waveform. A processor having memory is configured to represent the received waveform as a hybrid sinusoidal frequency modulated (FM)-polynomial phase signal (PPS) model. The hybrid sinusoidal FM-PPS model having PPS phase parameters representing a speed of the elevator car along a first direction and a sinusoidal FM phase parameter representing a vibration of the elevator car along a second direction. The processor solves the hybrid sinusoidal FM-PPS model to produce the speed of the elevator car or the vibration of the elevator car or both. A controller controls an operation of the elevator using the speed of the elevator car or the vibration of the elevator car, or both, to assist in an operational management of the elevator.