Vehicle Motor Failure Detection Sensitivity Adjustment
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Solution Overview
Problem
Existing failure detection systems for motor systems in electric and hybrid vehicles face challenges in accurately determining when to execute a fail-safe function, as the severity of failures can vary with operational conditions and situations, leading to either false alarms or neglected issues.
Innovation Solution
A failure detection device that adjusts its sensitivity based on the operational condition and situation of the motor system, increasing sensitivity for minor failures requiring immediate action and decreasing it when no serious failure is present, specifically by changing failure determination criteria in response to operational modes and sensor failures like offset failures in current sensors and interphase short-circuits in resolvers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the failure determination criteria are made strict to increase the failure detection sensitivity, then the failure detection sensitivity is improved, but the fail-safe function is frequently executed because a temporal deviation of the detected value that is negligible in a normal situation is immediately determined as a failure
Solution Approach 1:
The patent applies dynamics by making the failure determination threshold variable rather than fixed. The threshold is dynamically adjusted based on the operational state of the motor system, allowing the system to adapt its sensitivity to different operating conditions. This resolves the contradiction by enabling high sensitivity when appropriate while avoiding false alarms during normal operational variations.
Solution Approach 2:
The patent changes the parameter of the failure determination threshold based on operational conditions. By monitoring parameters such as motor current, voltage, and operational state, the system adjusts the threshold for what constitutes a failure. This allows the system to maintain high detection sensitivity for actual failures while tolerating normal operational deviations, thus resolving the contradiction between sensitivity and false detection rate.
2Reliability
If the failure determination criteria are relaxed to decrease the failure detection sensitivity, then the false failure detection rate is reduced, but occurrence of a failure which requires execution of a fail-safe function tends to be neglected
Solution Approach 1:
The system dynamically adjusts the failure determination threshold based on operational conditions, enabling it to maintain high reliability by avoiding false detections during normal operations while simultaneously maintaining high sensitivity to detect actual failures when they occur. The threshold is not fixed but adapts to the operational context.
Solution Approach 2:
The patent changes the determination parameter (threshold) based on the operational state of the motor system. When the system operates under conditions where deviations are normal, the threshold is relaxed. When operational conditions indicate potential failures, the threshold becomes more sensitive. This parameter adaptation resolves the contradiction between reducing false alarms and detecting actual failures.
3Device complexity
If a fixed failure determination criterion is used, then the system complexity is reduced, but the failure detection cannot adapt to different operational conditions and situations
Solution Approach 1:
The patent implements parameter changes by adjusting the failure determination threshold based on operational conditions such as motor current, voltage, and operational state. This allows the detection system to adapt to different situations without requiring a completely complex reconfiguration, achieving versatility through dynamic parameter adjustment rather than structural complexity.
Solution Approach 2:
The system performs self-adjustment of the failure determination criterion based on its own operational parameters. By monitoring its own operational state (current, voltage, temperature), the system automatically adapts its detection threshold without external intervention, achieving adaptability through self-service while maintaining relatively simple system architecture.
Data Source
AI summary
A failure detection device for a vehicle that detects a failure of a motor system includes a controller that changes a sensitivity for detection of a failure in the motor system in accordance with at least one of an operational condition of the motor system and a situation in which the motor system is operating.