Numerical Control Device Heat Radiation Estimation

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Solution Overview

Problem

Existing numerical control devices in motor drive systems lack precise estimation of heat radiation characteristics, leading to inadequate detection of cooling device abnormalities and potential overheating, as they rely on temperature differences without actual temperature detectors.

Innovation Solution

A numerical control device with a heat radiation characteristic estimation part that acquires and estimates heat radiation characteristics from component element temperatures, ambient temperature, input energy, and output energy, enabling the output of normal/abnormal judgment signals for the cooling device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If temperature detectors are not installed in the motor drive system, then device complexity is reduced, but measurement precision of heat radiation characteristics deteriorates

Engineering Contradiction:
Improvedevice complexityVSAvoidmeasurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent introduces an intermediary estimation mechanism that uses readily available data (current, voltage, ambient temperature) to infer heat radiation characteristics without direct temperature measurement. The control device calculates heat generation from electrical parameters and uses thermal models to estimate temperature and heat radiation, acting as a mediator between measurable electrical quantities and the unmeasurable thermal characteristics.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the physical temperature detection system (temperature detectors and sensors) with a computational estimation system. Instead of using mechanical/physical sensing devices to measure temperature directly, the system substitutes this with mathematical models that calculate heat radiation characteristics from electrical parameters, thereby eliminating the need for additional temperature sensing hardware.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If cooling device abnormalities are not detected, then device complexity is reduced, but reliability of the motor drive system deteriorates

Engineering Contradiction:
Improvedevice complexityVSAvoidreliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the control device continuously monitors heat radiation characteristics and compares them against normal operating ranges. When abnormalities are detected (such as reduced heat radiation indicating cooling fan failure), the system provides feedback by generating alarm signals or adjusting operation to prevent overheating, thereby maintaining system reliability through continuous monitoring and responsive control.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary detection of cooling device abnormalities by monitoring heat radiation characteristics before actual overheating damage occurs. The system proactively identifies issues such as cooling fan failures through changes in heat radiation patterns and takes preventive action (alarms, operation restrictions) before the problem leads to system failure, rather than waiting for temperature detectors to trigger after damage begins.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If heat radiation characteristic estimation is implemented, then detection precision of cooling abnormalities is improved, but device complexity increases

Engineering Contradiction:
Improvedetection precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent makes the control device multi-functional by enabling it to perform both its primary control function and heat radiation characteristic estimation using the same hardware resources. The control device utilizes existing sensors (current, voltage, ambient temperature) and its computational capabilities to simultaneously manage motor control and thermal monitoring, thereby achieving enhanced detection precision without adding dedicated estimation hardware.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The control device performs self-service by using its own computational resources and existing sensor data to estimate heat radiation characteristics. Rather than requiring separate dedicated estimation hardware, the control device leverages its inherent processing capabilities and the data it already collects for motor control, thereby achieving improved detection precision while minimizing additional device complexity.

Inventive Principle:
Principle #25Self-service

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

Enables the detection of cooling device abnormalities and prevention of performance drops and breakdowns by accurately estimating heat radiation characteristics, thereby preventing overheating and ensuring the reliability of motor drive systems.

Implementation Method 1

a heat radiation characteristic estimation part which estimates a heat radiation characteristic of component elements from a temperature of the component elements, an ambient temperature, input energy, and output energy

Methodology Applied
Scientific EffectHeat radiation: Thermal Radiation

Implementation Method 2

the cooling device is generally an air-cooling type cooling device which uses cooling fins... the cooling fan is driven by a fan motor to generate cooling air which cools the insides of the converter, inverter, and motor

Methodology Applied
Scientific EffectHeat dissipation: Thermal Radiation

Data Source

PatentUS10042346B2Numerical control device provided with heat radiation characteristic estimation part
Publication Date: 2018.08.07 FANUC LTD

AI summary

A numerical control device, in a motor drive system which drives a motor part which has a cooling fan motor and is provided with the numerical control device to drive the motor part, which acquires the temperature of the component elements of the motor part from the temperature detectors, ambient temperature, input energy to the component elements, and output energy from the component elements, estimates the heat radiation characteristic of the component elements from the data of the temperature of the component elements, ambient temperature, and input/output energy, compares the estimated value of the heat radiation characteristic of the component elements with a normal value, judges that the cooling fan motor is abnormal when the heat radiation characteristic is below the normal value, and thereby prevents trouble due to overheating of the component elements of the motor part.