Vehicle Motor Control Fail-Safe Using External Characteristic Data

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Solution Overview

Problem

When control processing for multiple motors is integrated into a single microcontroller, the processing load increases, leading to potential failures. Additionally, application-specific integrated circuits (ASICs) lack built-in memory for storing characteristic data for various vehicle types, resulting in inadequate fail-safe functionality when used on unsupported vehicle types.

Innovation Solution

A motor control device comprising a first storage unit for characteristic data related to multiple vehicle types, a second storage unit for vehicle type parameters, a processor for executing arithmetic processing based on these data, and a drive circuit that reads and corrects data to ensure appropriate motor control even when the processor fails.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If control processing for multiple motors is integrated into a single microcontroller, then device complexity is reduced, but processor load increases leading to potential failures

Engineering Contradiction:
Improvecontrol device structureVSAvoidprocessor operation reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent divides the control system into two independent parts: a microcontroller for high-level control and an ASIC for critical motor control processing. This segmentation allows the ASIC to handle time-sensitive motor control independently, reducing the microcontroller's processing load and preventing system failures while maintaining overall system reliability.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If ASIC is used without built-in memory for characteristic data, then device cost is reduced, but fail-safe function cannot be realized for unsupported vehicle types

Engineering Contradiction:
Improvedevice costVSAvoidfail-safe function
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent introduces an external memory device as an intermediary between the ASIC and the characteristic data storage. This external memory stores vehicle type-specific characteristic data and makes it available to the ASIC when needed, enabling the cost-effective ASIC design to support multiple vehicle types while maintaining fail-safe functionality.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent pre-stores characteristic data for multiple vehicle types in external memory before the fail-safe operation is needed. When the microcontroller detects an abnormality, the ASIC can immediately access the appropriate pre-stored data for the specific vehicle type, ensuring rapid and accurate fail-safe control without requiring built-in memory in the ASIC.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If ASIC executes control processing for vehicle types not supported by its built-in data, then device versatility is improved, but control accuracy deteriorates

Engineering Contradiction:
Improvevehicle type compatibilityVSAvoidmotor control accuracy
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent enables the ASIC to adapt to different vehicle types by dynamically loading vehicle-specific parameter data (characteristic data) from external memory. This allows the same ASIC hardware to maintain high control accuracy across multiple vehicle types by adjusting its operating parameters based on the specific vehicle configuration, rather than requiring hardware changes or built-in storage for each vehicle type.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4323222B1Motor control device and motor control method
Publication Date: 2025.06.04 TOYOTA JIDOSHA KK
  • EP4323222B1 patent drawingFigure 1
  • EP4323222B1 patent drawingFigure 2
  • EP4323222B1 patent drawingFigure 3

AI summary

A motor control device includes: a first storage unit that stores characteristic data related to drive control of a vehicle motor; a second storage unit that stores a vehicle type parameter related to a predetermined vehicle type; a processor that executes arithmetic processing related to the drive control corresponding to the predetermined vehicle type, based on the vehicle type parameter and the characteristic data; and a drive circuit that executes drive processing of a vehicle motor of the predetermined vehicle type, based on a result of the arithmetic processing, in which the drive circuit reads out the characteristic data from the first storage unit and the vehicle type parameter from the second storage unit when abnormality has occurred in the processor, and to execute the arithmetic processing related to the drive control corresponding to the predetermined vehicle type, based on the vehicle type parameter and the characteristic data.