Vehicle Suspension Controller Damping-Force Adjustment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing damping-force adjustable shock absorbers for vehicles often generate abnormal 'clattering noise' due to rapid changes in damping force, which current control configurations fail to fully suppress.
Innovation Solution
A suspension control apparatus with a controller that switches damping-force characteristics to a softer side when the direction of the shock absorber's stroke is reversed between extension and contraction, using a combination of sensors and processing units to manage damping force based on relative velocity and vibration analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the damping force is increased to damp unsprung vibration on the wheel side, then vibration damping performance is improved, but abnormal clattering noise is generated
Solution Approach 1:
The shock absorber dynamically adjusts its damping characteristics between hard and soft states based on real-time detection of unsprung vibration. The control apparatus varies the damping-force characteristics according to road conditions and vibration levels, transitioning from fixed damping to adaptive damping that responds to changing operational conditions.
Solution Approach 2:
The damping force parameter is changed based on detected vibration conditions. When unsprung vibration is detected exceeding threshold values, the damping force is increased to suppress vibration; when vibration is within acceptable ranges, the damping force is reduced to prevent clattering noise. This parameter adjustment resolves the contradiction between vibration suppression and noise prevention.
2Force
If the damping-force characteristics are controlled to be harder to increase damping force, then vibration damping is improved, but clattering noise is generated
Solution Approach 1:
The control apparatus continuously monitors unsprung vibration through sensors and uses this feedback to adjust the damping-force characteristics. When vibration exceeds thresholds, feedback triggers hard damping characteristics; when vibration is acceptable, feedback switches to soft characteristics to eliminate clattering noise. This closed-loop feedback system resolves the force-noise contradiction.
3Object-generated harmful factors
If the damping force is gradually changed or initial increase rate is reduced to suppress clattering noise, then noise suppression is improved, but vibration damping effectiveness is reduced
Solution Approach 1:
The control apparatus performs preliminary detection of unsprung vibration conditions before applying damping force changes. By detecting vibration thresholds in advance and preparing the appropriate damping characteristics, the system can switch to hard characteristics when vibration is detected, preventing clattering noise before it occurs rather than merely responding after the fact.
Data Source
AI summary
A suspension control apparatus for a vehicle including a damping-force adjustable shock absorber interposed between a vehicle body and a wheel of a vehicle, and a controller for variably controlling damping-force characteristics of the damping-force adjustable shock absorber between hard and soft. The controller is configured to switch the damping-force characteristics to a soft side when a direction of a stroke of the damping-force adjustable shock absorber is reversed between an extension stroke and a contraction stroke.