Motor Control Device Torque Stability via Sensor Feedback

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The controllability of turning angles in motors with two independent stator coils is compromised due to differences in detection values from rotation angle sensors, leading to potential decreases in motor torque control and stability.

Innovation Solution

A control device with two processing circuits that communicate and perform specific operation amount calculations to feedback-control convertible angles, using integral elements to adjust and stabilize torque, and switch between operation processes to manage differences in sensor detection values, thereby maintaining motor torque and controllability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate microcomputers control d/q-axis currents based on detection values from separate rotation angle sensors, then system redundancy is improved, but controllability of turning angle decreases due to differences between detection values

Engineering Contradiction:
Improvesystem redundancyVSAvoidcontrollability of turning angle
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent introduces an angle feedback unit as an intermediary that mediates between the two independent control units. This unit receives detection angles from both microcomputers, calculates the angle difference, and performs correction processing to reduce the error between the two detection systems, thereby maintaining controllability while preserving redundancy

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements an angle feedback control mechanism where the angle feedback unit continuously monitors the difference between detection angles from the two sensors and feeds back correction signals to reduce this difference, ensuring that the redundant system maintains consistent controllability

Inventive Principle:
Principle #23Feedback

2Measurement precision

If feedback control is performed on detection values to make them equal to target value, then angle accuracy is improved, but controllability decreases due to differences between sensor detection values

Engineering Contradiction:
Improveangle accuracyVSAvoidcontrollability
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The angle feedback unit serves as an intermediary that processes detection angles from both sensors before feedback control is applied. It calculates the difference between the two detection angles and performs correction processing, ensuring that feedback control is applied to corrected values rather than raw sensor values, thereby maintaining both accuracy and controllability

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If integral element is used to calculate operation amount for feedback control, then torque stability is improved, but sudden torque change occurs when switching between first and second use and operation processes

Engineering Contradiction:
Improvetorque stabilityVSAvoidswitching stability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent applies preliminary action by performing removal processing of the integral element's influence before switching from the first use and operation process to the second use and operation process. This preventive measure eliminates the accumulated integral value that would otherwise cause sudden torque changes during switching, thereby maintaining both torque stability and switching reliability

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The removal processing of the integral element's influence before switching acts as a preliminary anti-action against the potential harmful effect of sudden torque changes. By counteracting the accumulated integral value in advance, the system prevents the adverse effect of torque instability during process switching

Inventive Principle:
Principle #9Preliminary anti-action

Data Source

PatentEP3965288B1Control device
Publication Date: 2023.06.07 JTEKT CORP
  • EP3965288B1 patent drawingFigure 1
  • EP3965288B1 patent drawingFigure 2
  • EP3965288B1 patent drawingFigure 3(a)~3(b)

AI summary

A control device (20) controls a motor (10) which includes a first stator coil (14(1)) and a second stator coil (14(2)) insulated from each other. The control device (20) includes: a first drive circuit that is connected to the first stator coil (14(1)); a second drive circuit that is connected to the second stator coil (14(2)); a first processing circuit; and a second processing circuit. The first processing circuit increases an output of an integral element according to the number of control systems when the second processing circuit performs a process of switching a first use and operation process to a second use and operation process.