Preview Damping Control for Low-Frequency Sprung Vibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle control devices are insufficient in controlling sprung vibrations at low frequencies, as they do not accurately predict future sprung behavior from road surface information, leading to inadequate control and reduced ride comfort.
Innovation Solution
A vehicle behavior device that includes a force generation mechanism, a road surface state acquisition unit, and a vehicle sprung behavior prediction unit to predict future sprung behavior and adjust forces accordingly, using a controller to output command signals for optimal damping force control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If preview control is applied based on road surface information, then control of high-frequency vibrations is improved, but control of low-frequency sprung vibrations becomes insufficient
Solution Approach 1:
The patent introduces a sprung behavior prediction unit as an intermediary component that translates road surface information into predicted sprung behavior. This mediator bridges the gap between road surface detection and suspension control, enabling the system to account for the complex dynamic relationship between road inputs and vehicle body responses, particularly at low frequencies where direct control fails
Solution Approach 2:
The system performs preliminary prediction of sprung behavior before actual sprung vibrations occur. By using the sprung behavior prediction unit to forecast future sprung responses based on current road surface conditions, the control system can prepare appropriate control forces in advance, improving effectiveness at low frequencies where vibrations develop gradually
2Ease of operation
If control is based on road surface displacement directly, then unsprung control is improved, but sprung vibration control at resonant frequencies becomes insufficient
Solution Approach 1:
The sprung behavior prediction unit serves as a necessary intermediary that transforms simple road surface displacement data into meaningful predictions of sprung behavior. This intermediary layer maintains the simplicity of road surface sensing while adding the computational complexity needed to predict and control sprung vibrations at resonant frequencies
Solution Approach 2:
The system changes the parameter being controlled from direct road surface displacement to predicted sprung behavior. By transforming the control parameter through the prediction unit, the system adapts to different frequency characteristics of road inputs, making the control effective across both high and low frequency ranges including resonant frequencies
Data Source
AI summary
Provided is a vehicle behavior device including: a variable damper, which is provided between a vehicle body side and a wheel side of a vehicle, and is configured to adjust a force to be generated; a camera device configured to measure a road surface state forward of the vehicle; a future vehicle state estimation unit configured to predict a sprung behavior of the vehicle from a road surface displacement acquired by the camera device and a vehicle speed; and a command value calculation unit configured to obtain a force to be generated by the variable damper based on a predicted value obtained by the future vehicle state estimation unit, and output a command signal.