Active Shock Absorber Control for Faster Damping Response
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Solution Overview
Problem
Passive shock absorbers are dependent on road surface stresses, limiting dynamic performance and comfort, while existing active shock absorbers lack effective control methods to optimize damping response.
Innovation Solution
A method for controlling a road vehicle with active shock absorbers using electronically controlled actuators, position sensors, and accelerometers to generate autonomous movements, optimizing damping response through open-loop transfer functions based on vertical acceleration and translation speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If passive shock absorbers are used, then the system is simple and reliable, but the dynamic performance and comfort are limited because they are entirely dependent on road surface stresses
Solution Approach 1:
The patent applies the Dynamics principle by transitioning from passive shock absorbers with fixed characteristics to active shock absorbers with dynamically adjustable damping coefficients. The control unit continuously modifies the damping coefficient based on real-time road conditions and vehicle state, enabling the system to adapt its behavior dynamically rather than relying on predetermined passive characteristics.
Solution Approach 2:
The patent implements Parameter changes by varying the damping coefficient as a controllable parameter. The control unit adjusts this parameter based on inputs from accelerometers and position sensors, allowing the shock absorber to change its mechanical characteristics in response to different operating conditions, thereby improving both comfort and dynamic performance.
2Adaptability or versatility
If active shock absorbers with autonomous movements are used, then dynamic performance and comfort are improved, but the control method lacks effectiveness in optimizing damping response
Solution Approach 1:
The patent applies the Feedback principle by implementing a closed-loop control system where accelerometers measure vertical acceleration and position sensors measure translation speed, and this feedback information is used by the control unit to continuously adjust the damping coefficient. This ensures the active shock absorber responds effectively to road conditions while maintaining optimal damping performance.
Solution Approach 2:
The patent replaces purely mechanical passive shock absorbers with an electro-hydraulic active system controlled by electronic actuators. The control unit processes sensor signals and commands the actuator to adjust the damping coefficient, substituting mechanical intuition with electronic control and computational algorithms for optimizing damping response.
3Reliability
If complex control systems are implemented to optimize damping response, then damping effectiveness is improved, but the system complexity and implementation cost increase
Solution Approach 1:
The patent applies the Universality principle by designing a control unit that handles multiple functions: processing signals from accelerometers, reading position sensor data, calculating optimal damping coefficients, and controlling the actuator. This multi-functional approach consolidates complexity into a single control module rather than distributing it across multiple separate systems.
Solution Approach 2:
The control system implements self-service by autonomously determining the optimal damping coefficient based on real-time sensor inputs without requiring external intervention. The control unit continuously monitors vehicle state and road conditions, automatically adjusting the damping coefficient to optimize performance, thereby reducing the need for complex external control mechanisms.
Data Source
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AI summary
A method to control an active shock absorber (6) of a road vehicle (1). The active shock absorber (6) is part of a suspension (5) connecting a frame (4) of the road vehicle (1) to a hub (3) of a wheel (2) and has: a first element (7), which defines an end of the active shock absorber (6), a second element (8), which defines another end of the active shock absorber (6) and is mounted so as to slide relative to the first element (7); and an actuator (10), which is configured to generate a force (F), which is applied between the two elements (7, 8). The control method comprises the steps of: determining a vertical acceleration (az) of the hub (3); determining a speed (v) of translation between the two elements (7, 8) of the active shock absorber (6); determining a target force (FTGT) for the actuator (10) of the active shock absorber (6) based on the vertical acceleration (az) of the hub (3) and based on the speed (v) of translation between the two elements (7, 8) of the active shock absorber (6); and controlling the actuator (10) of the active shock absorber (6) so as to pursue the target force (FTGT).