Active Noise Control in Elevator Motors
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Solution Overview
Problem
Elevator systems experience noise and vibration issues due to the prioritization of strength over noise and vibration reduction in their design, which negatively impact the travel experience for occupants.
Innovation Solution
An active noise and vibration control system that includes sensors to detect noise and vibration, a controller to generate control signals, and power electronics to produce drive signals that adjust the electric machine's operation to reduce these disturbances, using the motor as an actuator to cancel noise-radiating vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the machine structure is designed to meet strength requirements first, then the structural strength is improved, but noise and vibration are worsened
Solution Approach 1:
The patent applies active noise control by using the motor to generate vibrations that are opposite in phase to the noise-radiating vibrations, thereby converting the harmful noise and vibration into beneficial canceling forces. The controller senses the noise and vibration, generates control signals, and adjusts the motor operation to produce counter-vibrations that reduce the overall noise and vibration levels.
Solution Approach 2:
The patent changes the operational parameters of the motor dynamically based on sensed noise and vibration levels. The controller adjusts the motor's drive signals in real-time to modify its vibration output, transforming it from a source of harmful vibrations into an active dampening element that reduces noise and vibration in the machine structure.
2Object-generated harmful factors
If active noise and vibration control is implemented, then noise and vibration are reduced, but device complexity is increased
Solution Approach 1:
The patent makes the motor multi-functional by using it both for its primary function of driving the elevator and for secondary noise and vibration control. The same motor that propels the elevator car also acts as an active dampener to reduce noise and vibration, eliminating the need for separate active noise control components and reducing overall system complexity.
Solution Approach 2:
The system uses the motor itself to control its own noise and vibration output rather than requiring external active noise control devices. The controller adjusts the motor's operation based on feedback from sensors, allowing the motor to self-regulate and reduce the harmful vibrations it generates during 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
Effectively reduces noise and vibration in elevator systems, enhancing the user experience by maintaining stable operation while minimizing unwanted noise and vibration.
Implementation Method 1
at least one sensor for sensing at least one of noise and vibration in the machine and generating at least one of a noise signal representing noise and a vibration signal representing vibration
Implementation Method 2
the controller generating control signals to reduce at least one of noise and vibration in the machine... using the motor as an actuator to cancel noise-radiating vibrations
Data Source
AI summary
A system for active control of noise and/or vibration includes an electric machine; at least one sensor for sensing at least one of noise and vibration in the machine and generating at least one of an audio signal representing noise and a vibration signal representing vibration; a controller obtaining at least one of the noise signal and the vibration signal, the controller generating control signals to reduce at least one of noise and vibration in the machine; and power electronics receiving the control signals and generating drive signals for the machine.