Vehicle Control Device Sprung Mass Estimation Accuracy
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Solution Overview
Problem
Existing vehicle control systems face challenges in accurately estimating the sprung mass state when disturbances in wheel speed occur within a predetermined frequency region, leading to reduced accuracy and potential control issues.
Innovation Solution
A vehicle control device and method that estimates the sprung mass state using wheel speed information from sensors, calculates a reference wheel speed based on a vehicle body plan view model, and adjusts actuators to maintain a target state, while detecting deteriorated estimation accuracy through differential analysis in specific frequency regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If wheel speed information in a predetermined frequency region is used to estimate sprung mass state, then control can be implemented using available sensor data, but estimation accuracy deteriorates when disturbances occur in that frequency region
Solution Approach 1:
The system dynamically switches between two different estimation approaches based on operating conditions: using wheel speed information when estimation accuracy is sufficient, and switching to alternative methods when disturbances are detected. This dynamic adaptation resolves the contradiction by allowing the system to use available sensor data normally while protecting against accuracy deterioration when disturbances occur.
Solution Approach 2:
The system continuously monitors estimation accuracy by detecting disturbances in the predetermined frequency region and uses this feedback to determine when to switch estimation methods. This feedback mechanism enables the system to maintain accuracy by detecting when wheel speed-based estimation is compromised and switching to alternative approaches.
2Duration of action of stationary object
If control continues using estimated sprung mass state, then control operations can be maintained without interruption, but control quality deteriorates when estimation accuracy is low
Solution Approach 1:
The control system dynamically adjusts its operation mode based on estimation accuracy: maintaining continuous control using wheel speed-based estimation when accuracy is sufficient, and switching to alternative control strategies when accuracy deteriorates. This ensures continuous operation while maintaining control quality by adapting to changing estimation conditions.
Solution Approach 2:
The system prepares alternative control methods in advance to handle cases where wheel speed-based estimation becomes unreliable. By having pre-prepared fallback strategies, the system can maintain control quality without interruption even when the primary estimation method deteriorates.
Data Source
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AI summary
In this vehicle control device, a sprung mass state is estimated based on information in a predetermined frequency region of wheel speed detected by a wheel speed sensor, an actuator is controlled so as to bring the estimated sprung mass state to a target sprung mass state, and a reference wheel speed for each wheel is calculated based on a vehicle body plan view model. When a differential among reference wheel speeds of the wheels to the low-frequency side from the predetermined frequency region in which sprung mass behavior appears is equal to or greater than a prescribed value, the sprung mass state estimation accuracy is detected to have been lowered, and control performed by an actuator orientation control means is implemented in a more limited fashion than when estimation accuracy has not deteriorated.