Motor Control Device Using Adaptive Observer for Inertial Load Estimation

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Solution Overview

Problem

Existing motor control systems face challenges in accurately calculating and adapting to inertial load values, leading to instability and vibrations, especially under varying load conditions and modeling errors.

Innovation Solution

A motor control device and method that utilize an adaptive observer to calculate an estimated inertial load value, based on the motor output command and actual output, and adjust the inertial load value calculation using a reference range to enhance stability and accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If an adaptive observer is used to calculate the inertial load value based on motor output command and actual output, then the accuracy of inertial load value calculation is improved, but the device complexity increases

Engineering Contradiction:

Improveinertial load value calculation accuracyVSAvoidcontrol device structure

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical measurement systems with a computational approach using an adaptive observer algorithm. The inertial load value is calculated through signal processing of motor output commands and actual outputs rather than direct mechanical sensing, reducing hardware complexity while improving measurement accuracy through adaptive estimation techniques.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The adaptive observer acts as an intermediary computational layer between the motor control system and the inertial load calculation. It processes motor output commands and actual outputs to generate accurate inertial load value estimates without requiring direct access to physical inertial properties, thereby simplifying the overall system architecture.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the inertial load value is continuously adapted based on actual motor output, then the adaptability to varying load conditions is improved, but the stability of motor control may deteriorate due to vibrations and disturbances

Engineering Contradiction:

Improveload condition adaptationVSAvoidmotor control stability

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent implements dynamic adaptation of the inertial load value through the adaptive observer, which continuously updates its estimates based on current motor output commands and actual outputs. This dynamic approach allows the system to adapt to varying load conditions while maintaining stability through controlled adaptation rates and filtering mechanisms that prevent excessive sensitivity to transient disturbances.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The adaptive observer utilizes feedback from motor actual outputs to continuously refine the inertial load value estimation. This feedback mechanism enables the system to adapt to changing load conditions while the controlled feedback gain ensures stability by preventing overreaction to transient disturbances and vibrations.

Inventive Principle:

Principle #23Feedback

3Productivity

If the motor control system uses a fixed inertial load value, then the device complexity is reduced, but the productivity decreases due to poor disturbance response and vibrations under varying load conditions

Engineering Contradiction:

Improvedisturbance response performanceVSAvoidinertial load value calculation

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The motor control system performs self-identification of the inertial load value through the adaptive observer, which automatically adapts to the actual load conditions without requiring external calibration or manual intervention. This self-service capability improves disturbance response performance and productivity while maintaining reasonable system complexity through algorithmic rather than hardware-based solutions.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS10425028B2Motor control device and method of controlling motor

Publication Date: 2019.09.24 YASKAWA DENKI KK

AI summary

A motor control device includes output command calculation circuitry and inertial load value calculation circuitry. The output command calculation circuitry is configured to calculate a motor output command, based on a motor acceleration command and an inertial load value indicative of a magnitude of inertia of a load on a motor. The inertial load value calculation circuitry is configured to calculate an estimated inertial load value with an adaptive observer, based on the motor output command and a motor actual output to be output from the motor, and configured to calculate the inertial load value, based on the estimated inertial load value.