Active Suspension Road Height Filtering for Ride Comfort Control
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Solution Overview
Problem
Existing active suspension control systems risk deteriorating ride comfort when road surface detection is abnormal, leading to inadequate control of rear wheel actuators based on estimated vertical acceleration.
Innovation Solution
An active suspension device with a road surface height measurer, position detector, and road surface condition determiner that measures and corrects road surface heights at multiple points, excluding outliers and determining road surface conditions to prevent ride comfort deterioration by controlling damping forces effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the actuator of the rear wheels is controlled depending on the vertical acceleration estimated from the vertical acceleration stored in the storage when displacement detection is abnormal, then the control system can operate without road surface detection data, but the ride comfort of the occupant deteriorates
Solution Approach 1:
The system performs preliminary actions by measuring road surface heights at three or more points before control decisions are made. The road surface height measurer captures data in advance, and the position detector identifies abnormal positions ahead of time, allowing the controller to prepare appropriate control commands before the vehicle encounters the abnormal road section, thus maintaining ride comfort even when detection is partially abnormal
Solution Approach 2:
The invention introduces intermediary elements between the vertical acceleration sensor and the actuator control. Instead of directly using estimated vertical acceleration from storage, the system uses road surface height measurements at multiple points as an intermediary to detect abnormal positions, then uses this information to adjust actuator control. This intermediary road surface height data provides more accurate information for maintaining ride comfort than direct vertical acceleration estimation alone
2Ease of operation
If the road surface height measurement is used directly without excluding outlier values, then the measurement process is simple, but the accuracy of road surface condition determination deteriorates due to outliers like stones or leaves
Solution Approach 1:
The system applies local quality by treating different measurement points differently based on their local characteristics. The position detector identifies specific locations where the road surface height difference exceeds the threshold, indicating local abnormalities such as stones or leaves. Only the outlier values at these specific local positions are excluded, while other valid measurement points are retained for road surface condition determination, thus maintaining measurement precision without unnecessarily complicating the overall measurement process
Solution Approach 2:
The invention applies partial action by selectively excluding only the necessary outlier values rather than processing all measurements equally. The position detector identifies specific abnormal positions, and the controller excludes only those particular outlier values from road surface condition determination. This partial exclusion approach removes harmful outliers while preserving valid measurement data, achieving accurate road surface condition determination without requiring complete re-measurement or complex processing of all data points
Data Source
AI summary
An ECU includes: a road surface height measurer which measures road surface heights at three or more points along a vehicle-width direction in front of a tire mounted on a wheel; a position detector which detects a position at which a difference of the road surface height from an adjacent road surface height is equal to or larger than a predetermined threshold among the road surface heights at three or more points measured by the road surface height measurer; and a road surface condition determiner which excludes a value of the road surface height at the position at which the difference detected by the position detector is equal to or larger than the predetermined threshold, and determines a condition of the road surface based on the road surface heights at positions at each of which the difference from an adjacent road surface height is smaller than the predetermined threshold.