Lateral Acceleration Sensor Breakdown Detection for Four-Wheel Drive Vehicles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lateral acceleration sensor breakdown detection systems in four-wheel drive vehicles can incorrectly diagnose sensor failures when driving on low-friction surfaces, leading to unnecessary fail-safe operations and increased serviceability issues.
Innovation Solution
A breakdown detection device that suspends breakdown determination control when the vehicle is spinning by oversteering, using the yaw rate sensor to accurately calculate the estimated lateral acceleration and prevent false diagnoses, ensuring accurate power distribution control based on actual lateral acceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the breakdown detection device determines breakdown based on the difference between actual lateral G and estimated lateral G, then breakdown detection capability is improved, but false diagnosis occurs when spinning by oversteering
Solution Approach 1:
The breakdown determination control is dynamically suspended based on real-time detection of spinning conditions. The system continuously monitors wheel rotation speeds and automatically adjusts the breakdown determination logic: when spinning by oversteering is detected (outer wheel speed ≤ inner wheel speed during turning), the breakdown determination is suspended; when normal conditions prevail, breakdown determination proceeds normally. This dynamic adaptation resolves the contradiction by making the detection system flexible to different driving states.
Solution Approach 2:
The system changes the operational parameters of the breakdown determination control based on detected vehicle state. When spinning conditions are detected, the determination threshold or control activation parameter is changed (suspended), preventing false diagnosis. This parameter change allows the system to maintain high reliability in normal conditions while avoiding measurement precision issues during spinning.
2Reliability
If fail safe operation is carried out when breakdown is detected, then vehicle safety is improved, but unnecessary fail safe operation occurs causing serviceability issues
Solution Approach 1:
The fail-safe operation is dynamically controlled based on the breakdown determination result. By suspending the breakdown determination control when spinning by oversteering is detected, the system prevents erroneous activation of fail-safe operations. This ensures that fail-safe operations are only executed when actual breakdowns occur, maintaining vehicle safety while avoiding unnecessary interventions that would compromise serviceability.
3Reliability
If the breakdown determination control is always active, then breakdown detection reliability is improved, but false breakdown determination occurs on low friction surfaces
Solution Approach 1:
The breakdown determination control is applied selectively based on local vehicle conditions. Instead of uniformly applying the determination logic in all situations, the system identifies specific local conditions (spinning by oversteering detected through wheel speed comparison) and suspends the control only in those localized scenarios. This allows high reliability in normal conditions while avoiding false determinations during spinning, effectively resolving the contradiction through spatial and conditional selectivity.
Data Source
AI summary
A lateral G sensor breakdown detection device configured to carry out a breakdown determination control that determines that the lateral G sensor has a breakdown when the difference between the actual lateral G acting on a four wheel drive vehicle measured by the lateral G detection sensor installed on the vehicle and the estimated lateral G estimated and calculated from predetermined parameters that express the condition of the vehicle; while the vehicle is turning when the rotation speed of the outer wheel is equal to or less than the rotation speed of the inner wheel and when the actual lateral G is less than the estimated lateral G and the difference is greater than a predetermined value, the breakdown determination control is suspended.