Vehicle Suspension Device Longitudinal Vibration Control
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Solution Overview
Problem
Existing vehicle suspension systems face limitations in reducing longitudinal vibration of the vehicle body while maintaining operation stability, as increasing longitudinal compliance to minimize vibration transmission compromises ride comfort and stability.
Innovation Solution
The suspension device optimizes the longitudinal characteristics of one wheel by setting a target complex spring constant in the suspension of the other wheel, using a product of transmission force and sensitivity to minimize vehicle body excitation force, thereby reducing longitudinal vibration without compromising stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the longitudinal compliance of the suspension is increased to decrease the longitudinal force transmitted to the vehicle body, then the longitudinal vibration of the vehicle body is reduced, but the operation stability of the vehicle decreases
Solution Approach 1:
The patent applies parameter changes by optimizing the complex spring constant (a physical parameter) of the suspension system. Specifically, it sets the complex spring constant in the longitudinal direction of one suspension based on the transmission force characteristic and sensitivity of the other wheel, thereby adjusting the suspension's stiffness characteristics to reduce vibration transmission while maintaining stability
Solution Approach 2:
The patent implements feedback by using the transmission force characteristic and sensitivity of one wheel to determine the complex spring constant of the other suspension. This creates a coupled control system where the suspension parameters are adjusted based on system-wide vibration characteristics rather than isolated wheel parameters
2Object-affected harmful factors
If the magnitude of the component in the vehicle longitudinal direction of the force generated by elastic deformation of the elastically deformable member is increased to cancel longitudinal force, then the longitudinal vibration of the vehicle body is decreased, but the primary function of the suspension is impaired
Solution Approach 1:
The patent changes the parameter of complex spring constant to optimize the balance between vibration suppression and suspension function. By precisely adjusting this parameter based on transmission force characteristics, it achieves vibration reduction without excessive longitudinal compliance that would impair the suspension's primary function
Solution Approach 2:
The patent applies partial action by selectively optimizing only the complex spring constant in the longitudinal direction of one suspension, rather than increasing compliance across all suspension parameters. This targeted approach reduces vibration while maintaining adequate suspension performance
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively decreases longitudinal vehicle body vibration, enhancing ride comfort without affecting operation stability by adjusting the complex spring constant in the suspension system.
Implementation Method 1
Each of the suspensions includes an elastically deformable member, e.g., a suspension spring, for allowing relative displacement between the wheel and the vehicle body
Implementation Method 2
a shock absorber for generating a damping force
Data Source
AI summary
A characteristic is set to a first transmission force characteristic. A sensitivity is set to a first sensitivity. The maximum value of the square of a product of a value representing the first transmission force characteristic and a value representing the first sensitivity in a predetermined frequency range preset so as to include a frequency at which the value representing the first transmission force characteristic takes a peak value is set to an evaluation indication value. A complex spring constant in the vehicle longitudinal direction of the rear wheel suspension is set so that the evaluation indication value takes the minimum value out of values in a variable range of the evaluation indication value.