Active Chassis Damping With Vibration-Adaptive Scaling
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Solution Overview
Problem
Existing active and semi-active suspension systems face a conflict between vehicle body vibration damping and ride comfort, particularly at lower speeds, due to the reliance on vehicle speed-dependent scaling factors that compromise comfort when damping larger vibrations.
Innovation Solution
An adaptive control system with a control unit and evaluation unit that adjusts the scaling factor based on both vehicle speed and the intensity of body vibrations, allowing temporary increases in damping when larger vibrations are detected.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a vehicle speed-dependent scaling factor is used to dampen body vibrations, then body vibration damping is improved, but ride comfort deteriorates at lower speeds
Solution Approach 1:
The patent applies dynamics by making the scaling factor time-varying rather than solely speed-dependent. The scaling factor is adapted in real-time based on both vehicle speed and actual body vibration measurements, allowing the system to dynamically adjust damping levels. This enables the system to maintain low damping (high comfort) during normal low-speed operation while providing strong damping when vibrations are detected, thus resolving the contradiction between vibration damping and ride comfort.
Solution Approach 2:
The patent changes the parameters used to determine the scaling factor from only vehicle speed to a combination of vehicle speed and actual body vibration intensity. By introducing vibration intensity as an additional parameter, the system can distinguish between normal vibrations (where comfort is prioritized) and significant vibrations (where damping is prioritized), thereby resolving the contradiction through multi-parameter control.
2Reliability
If the scaling factor is increased to dampen larger vibrations, then body vibration damping is improved, but ride comfort deteriorates
Solution Approach 1:
The patent implements periodic action by applying high damping only temporarily when vibrations exceed a threshold, rather than continuously. The scaling factor is increased to dampen significant vibrations and then reduced again when vibrations subside. This periodic application of strong damping allows the system to handle large vibrations effectively while maintaining comfort during normal operation, resolving the contradiction between vibration damping and ride comfort.
Solution Approach 2:
The patent applies partial action by using a low scaling factor for most of the time (during normal operation) and temporarily increasing it only when necessary (during significant vibrations). This partial application of strong damping avoids the continuous comfort degradation that would result from maintaining high damping levels, thus resolving the contradiction between vibration damping capability and ride comfort.
3Ease of operation
If a low scaling factor is used to improve ride comfort, then ride comfort is improved, but body vibration damping deteriorates
Solution Approach 1:
The patent applies feedback by continuously monitoring actual body vibration intensity and using this information to adjust the scaling factor. When vibrations exceed a threshold, the system increases the scaling factor to provide adequate damping. This feedback mechanism ensures that the system maintains low damping (high comfort) during normal operation while automatically providing strong damping when needed, thus resolving the contradiction between ride comfort and vibration damping.
Solution Approach 2:
The patent makes the damping characteristic dynamic by adjusting the scaling factor based on real-time vibration feedback. The system transitions from a static low damping state (for comfort) to a dynamic state where damping is increased only when vibrations are detected. This dynamic adaptation resolves the contradiction by allowing the system to maintain comfort as the default state while providing damping capability when required.
Data Source
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AI summary
The invention relates to an active chassis control system for a motor vehicle with an adaptive control loop for reducing body vibrations (Aist) of the motor vehicle. The system incorporates a control unit (15) which, depending on a current body vibration (Aist) or a correlated parameter (a), actuates a chassis actuator (11). An adaptation unit (17) is connected downstream of the control unit (15). This adaptation unit adapts a control signal (S) generated by the control unit (15) with a vehicle speed-dependent scaling factor (f(v)), thereby forming an adapted control signal (S') with which the chassis actuator (11) can be actuated. According to the invention, depending on the situation, in the case of a significantly larger body vibration (Ao), a factor adjustment (Δf) can be added to the vehicle speed-dependent scaling factor (f(v)) in order to effectively dampen the significantly larger body vibration (Ao).