Motor-Driven Actuator Control With Virtual Spring Behavior

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Solution Overview

Problem

Existing mechanical and electrical configurations for controlling kinetic energy in contact mechanisms, such as springs, dampers, and actuators, face challenges in controlling forces below their own weight, require complex control logic, and have low position accuracy.

Innovation Solution

A drive system incorporating an actuator driven by a motor, with a controller that creates a physical model based on displacement, determines a spring constant, and selectively generates control instructions to achieve ideal spring behavior, allowing for easy configuration and simulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If mechanical configurations (spring, damper, air cylinder) are used to attenuate kinetic energy, then force generation capability is limited to forces greater than or equal to their own weight, but device complexity increases when designing mechanisms to overcome this limitation

Engineering Contradiction:

Improveforce generation capabilityVSAvoidmechanism design complexity

Core Design Contradiction:

ForceVSDevice complexity

Solution Approach 1:

The patent replaces mechanical configurations (springs, dampers, air cylinders) with an electrical configuration using a motor-driven actuator. This substitution eliminates the limitation of being unable to control forces less than or equal to the mechanism's own weight, while avoiding the need for complex mechanism designs to overcome such limitations.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the control parameter from mechanical force generation to electrical motor control. By controlling the motor's output through electrical signals, the system can precisely generate any desired force including forces less than or equal to the actuator's own weight, without requiring complex mechanical mechanisms.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If electrical configuration with motor-driven actuator is used, then position accuracy and force control below own weight are improved, but control logic configuration becomes complicated and requires time-consuming parameter tuning

Engineering Contradiction:

Improveposition accuracyVSAvoidcontrol logic complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent creates a virtual model that copies the mechanical characteristics of a spring in software. This virtual spring model allows the motor-driven actuator to reproduce ideal spring behavior through control algorithms, eliminating the need for complex physical mechanism designs while maintaining simple and intuitive control logic based on Hooke's Law.

Inventive Principle:

Principle #26Copying

3Device complexity

If mechanical configurations are used, then device structure is simple, but position accuracy is low and cannot control forces less than or equal to own weight

Engineering Contradiction:

Improvestructural simplicityVSAvoidposition accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces complex mechanical configurations with a simpler motor-driven actuator system. The actuator's built-in encoder provides high position accuracy, and the electrical control system enables precise force control including forces less than or equal to the actuator's own weight, all while maintaining relatively simple device structure.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical 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 enables precise control of forces and displacements following physical formulas, simplifying control logic and reducing deviations in actual device configurations, while absorbing excessive loads and preventing point loads.

Implementation Method 1

an actuator (2) that is driven by a motor (18) to generate displacement

Methodology Applied

Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

generate drive force calculated based on a product of the spring constant and the displacement generated in the actuator

Methodology Applied

Scientific EffectHooke's Law: Hooke's Law

Data Source

PatentUS12515325B2Drive system, control method, and control program

Publication Date: 2026.01.06 OMRON CORP

AI summary

A drive system includes an actuator that is driven by a motor to generate displacement, a driver that drives the motor, and a controller that gives a control instruction to the driver. The controller creates a physical model based on displacement caused by application of an external load to the actuator; generates a first control instruction to the motor such that the actuator generates the displacement according to the physical model; determines a spring constant; generates a second control instruction to the motor so as to generate drive force calculated based on a product of the spring constant and the displacement generated in the actuator; and selects and validates one of the first and second control instructions.