Motor Controller Vibration Suppression for Industrial Machines

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Solution Overview

Problem

Industrial machines with movable parts suspended in the air face challenges in reducing vibration amplitudes at the machine end relative position due to varying natural frequencies of the stand, which affects the robustness of vibration suppression controllers.

Innovation Solution

A motor controller that includes an error suppression compensation unit, acceleration extraction unit, acceleration compensation unit, machine end correction unit, and addition unit to control the machine end relative position, using a position command signal and motor position signal to generate a driving signal that decreases vibration amplitudes at the machine end relative position by adjusting the amplitude and phase of the proportional compensation signal based on machine end adjustment parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a vibration suppression compensator with fixed natural frequency parameters is used, then vibration suppression works well at specific positioning sites, but the robustness against parameter changes and adaptability to different installation environments deteriorates

Engineering Contradiction:

Improvevibration suppression effectivenessVSAvoidadaptability to different positioning sites

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by making the vibration suppression parameters adaptive rather than fixed. The controller dynamically adjusts the natural frequency and attenuation coefficient parameters based on feedback from acceleration sensors and position sensors, allowing the system to adapt to different installation environments and positioning sites while maintaining effective vibration suppression.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements feedback mechanisms using acceleration sensors to detect stand vibration and position sensors to monitor motor position. This feedback information is used to continuously adjust the vibration suppression compensator parameters, enabling the system to maintain optimal performance across varying operating conditions and installation environments.

Inventive Principle:

Principle #23Feedback

2Reliability

If machine stand acceleration feedback with band pass filtering is used, then robustness against parameter changes improves, but the ability to decrease vibration amplitude at machine end relative position deteriorates

Engineering Contradiction:

Improverobustness against parameter changesVSAvoidvibration amplitude at machine end

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the control strategy into multiple independent components: a vibration suppression compensator for reducing stand vibration, a feedforward controller for trajectory tracking, and a feedback controller for error correction. Each component operates with optimized parameters, allowing the vibration suppression to focus on stand stability while other components handle positioning precision at the machine end.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent makes the vibration suppression parameters dynamic and adaptive rather than fixed. The natural frequency and attenuation coefficient are continuously adjusted based on real-time feedback from acceleration and position sensors, enabling effective vibration suppression across different operating conditions while maintaining the ability to control machine end vibration through coordinated control of multiple components.

Inventive Principle:

Principle #15Dynamics

3Speed

If the stand has low stiffness to allow movable part suspension, then positioning speed improves, but vibration from reaction force increases

Engineering Contradiction:

Improvepositioning speedVSAvoidvibration amplitude

Core Design Contradiction:

SpeedVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary anti-action by using the vibration suppression compensator to predict and counteract stand vibration before it significantly impacts positioning accuracy. The compensator pre-adjusts the motor command based on anticipated vibration from reaction forces, allowing the system to maintain high positioning speed with low-stiffness stands while preventing excessive vibration at the machine end.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The patent implements dynamic vibration suppression that adapts to the actual stand characteristics and operating conditions. By continuously adjusting suppression parameters based on real-time feedback, the system can maintain high positioning speed with lightweight, low-stiffness stands while dynamically compensating for vibration generated during operation.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS10261520B2Motor controller and industrial machine

Publication Date: 2019.04.16 MITSUBISHI ELECTRIC CORP

AI summary

A motor controller includes: an error suppression compensation unit that outputs an error suppression signal for driving the motor such that a difference between the position command signal and a signal based on the motor position signal equals zero; an acceleration extraction unit that outputs an acceleration component of a natural frequency of a stand from a stand vibration signal; an acceleration compensation unit that outputs a proportional compensation signal obtained by multiplying the stand acceleration signal by a proportional gain; a machine end correction unit that outputs a machine end correction signal, and decreases an amplitude of vibration at the machine end relative position; and an addition unit that outputs a signal obtained by adding the machine end correction signal to the error suppression signal.