Vehicle Drive Unit Control Device Error Detection Reliability
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Solution Overview
Problem
Existing vehicle drive unit control systems face reliability issues due to deviations in error detection judgments between independently executing programs with different calculation cycles, leading to potential misjudgments in error avoidance actions and challenges in implementing effective shutdown procedures during faults.
Innovation Solution
A vehicle drive unit control device with two independent modules for error detection, where the second module monitors the first module's error detection and performs shutdown control if errors persist, and includes a nonvolatile memory to record emergency shutdowns, ensuring reliable error detection and recovery actions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two independent programs with different calculation cycles are used for error detection, then error detection coverage is improved, but judgment deviation between programs occurs
Solution Approach 1:
A judgment coincidence determination unit is introduced as an intermediary mechanism that receives detection results from both the first program (main program) and the second program (subordinate program). This unit compares the results and determines whether they coincide, thereby mediating the judgment deviation issue between programs with different calculation cycles and ensuring consistent error detection judgments.
2Reliability
If the second program monitors the first program with a longer cycle, then monitoring capability is improved, but response time to errors increases
Solution Approach 1:
The system dynamically adjusts the monitoring behavior based on the operational state. The second program operates with a longer cycle for normal monitoring to reduce processing load, but when the judgment coincidence determination unit detects a deviation between program judgments, the system activates emergency shutdown control. This dynamic response mechanism ensures both monitoring capability and timely error response.
Solution Approach 2:
The judgment coincidence determination unit continuously compares detection results from both programs in advance, before critical errors occur. When a deviation is detected, the system prepares for emergency shutdown by identifying the discrepancy early, allowing for faster response when actual errors occur without waiting for the longer monitoring cycle to complete.
3Reliability
If emergency shutdown is performed for major faults, then system safety is improved, but recovery complexity increases
Solution Approach 1:
A shutdown abnormality determination unit provides feedback after emergency shutdown is executed. This unit determines whether the shutdown resulted from a genuine major fault or from a judgment deviation between programs. By providing this feedback mechanism, the system can distinguish between actual safety-critical failures and false positives, enabling appropriate recovery actions and reducing unnecessary recovery complexity.
Data Source
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AI summary
This invention provides a control device and so forth in which there is an improvement in the reliability of error detection in a case where a single control section performs control of a drive unit of a vehicle by concurrently executing two programs that are mutually independent. A vehicle drive unit control device 1 includes a control section 10 that executes a first level module 20 that detects errors in a drive unit of a vehicle and a second level module 30 that detects errors in the drive unit independently of and concurrently with the first level module 20. The second level module 30 has a function of monitoring the error detection of the first level module 20 and performs shutdown control of the drive unit when the first level module 20 continues to detect an error in the drive unit for a predetermined amount of time or longer.