Suspension Damper Valve Control Near Hydraulic End Stops
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Solution Overview
Problem
Hydraulic dampers in vehicle suspension systems often encounter end stop contact due to road irregularities, leading to discomfort, unwanted body motion, noise, and potential damage, which existing control systems fail to adequately prevent.
Innovation Solution
A damping control system with a valve control module that selectively closes valves to restrict hydraulic fluid flow when the piston approaches an end stop, increasing the damping coefficient and preventing contact by maintaining valves fully open outside the end stop range and selectively closing them within the range to manage piston position and vehicle operation modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the valve remains fully open to maintain optimal damping performance, then the damping coefficient is kept low for comfort, but the piston may contact the end stop causing discomfort and potential damage
Solution Approach 1:
The control system performs preliminary action by detecting plunger position and predicting potential end stop contact before it occurs. When the plunger approaches the end stop region, the system proactively adjusts valve positioning to prevent contact, rather than reacting after contact occurs. This predictive control maintains reliability while preserving ride comfort through smooth, anticipatory adjustments.
Solution Approach 2:
The system dynamically adjusts valve positioning based on real-time plunger position feedback. The valve control module continuously monitors plunger location and modifies valve opening degree accordingly, creating a dynamic damping coefficient that adapts to instantaneous suspension conditions. This dynamic adjustment prevents end stop contact while maintaining optimal comfort during normal operation.
2Reliability
If the valve is closed to prevent end stop contact, then reliability is improved, but the damping coefficient increases causing harsher ride and reduced comfort
Solution Approach 1:
The system applies partial action by adjusting valve positioning only to the extent necessary to prevent end stop contact, rather than fully closing the valve. The control module calculates the minimum required valve adjustment based on plunger position and damping force requirements, making precise partial adjustments that provide just enough protection while maintaining comfort and minimizing control complexity.
Solution Approach 2:
The system employs feedback control by continuously monitoring plunger position and using this information to adjust valve positioning. The valve control module receives real-time position data, compares it against safe operating thresholds, and automatically adjusts valve opening accordingly. This closed-loop feedback mechanism simplifies control by using direct position-based decisions rather than complex predictive algorithms.
3Reliability
If the valve positioning is adjusted frequently to prevent end stop contact, then reliability is improved, but energy consumption increases
Solution Approach 1:
The control system implements periodic action by adjusting valve positioning at specific intervals or when plunger position thresholds are reached, rather than continuously modulating the valve. The valve control module monitors plunger position and triggers valve adjustments only when necessary based on position-based criteria, creating a periodic control pattern that reduces energy consumption while maintaining reliable end stop protection.
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
Effectively prevents piston contact with end stops, reducing discomfort and potential damage while maintaining optimal damping performance, thereby enhancing ride comfort and extending damper lifespan.
Implementation Method 1
A valve control module is provided which selectively closes valves to restrict hydraulic fluid flow when a piston of the damper becomes within a predetermined distance of an end stop
Implementation Method 2
Hydraulic dampers in vehicle suspension systems often encounter end stop contact due to road irregularities, leading to discomfort, unwanted body motion, noise, and potential damage
Data Source
AI summary
A damping control system includes: a damping chamber connected to one of (a) a body of a vehicle and (b) a wheel of the vehicle; a piston that is slidably disposed within the damping chamber and that includes: a piston rod that is connected to the other one of (a) the body of the vehicle and (b) the wheel of the vehicle; and a plunger that is connected to the piston rod and that divides the damping chamber into a first chamber and a second chamber; a first valve that regulates hydraulic fluid flow out of the first chamber; and a valve control module configured to selectively close the first valve when a position of the plunger is between (a) a first reference position within the first chamber and (b) a first end stop of the damping chamber that defines a boundary of the first chamber.