Active Shock Absorber Control for Center-of-Gravity Lowering

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Solution Overview

Problem

Active shock absorbers in road vehicles face challenges in maximizing performance while driving near the grip limit, as existing control methods do not effectively manage dynamic conditions such as cornering, where the distribution of load and pitch can lead to reduced grip and stability.

Innovation Solution

A method for controlling active shock absorbers using an electronic control unit that adjusts the position and force of each shock absorber based on real-time acceleration, steering angle, and yaw speed data to optimize the center of gravity, roll, and pitch angles, thereby improving grip and stability by dynamically adjusting the load distribution and anti-roll moment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If active shock absorbers are used to improve vehicle performance and comfort, then the vehicle can react to road stresses autonomously, but the control complexity and device complexity increase significantly

Engineering Contradiction:
Improvevehicle performanceVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by continuously adjusting the shock absorber characteristics in real-time based on varying road conditions and vehicle state. The control system dynamically modifies damping forces according to measured parameters like acceleration, steering angle, and yaw rate, allowing the suspension to adapt optimally to changing conditions rather than using fixed characteristics.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback control by using sensors to continuously monitor vehicle state parameters (acceleration, steering angle, yaw rate) and road conditions, then using this information to adjust the active shock absorber forces. The control unit processes this feedback information and commands the actuators to provide appropriate counter-forces, creating a closed-loop control system that optimizes performance while managing complexity through intelligent control algorithms.

Inventive Principle:
Principle #23Feedback

2Stability of the object's composition

If the vehicle body is lowered during cornering to improve stability, then grip and stability increase, but the complexity of control algorithms and processing increase

Engineering Contradiction:
Improvevehicle stabilityVSAvoidcontrol algorithm complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by anticipating the need for stability control during cornering and activating the appropriate shock absorber forces in advance. The control system detects cornering conditions through sensors (steering angle, yaw rate, acceleration) and pre-adjusts the suspension characteristics before the vehicle reaches critical stability thresholds, allowing proactive rather than reactive control.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements parameter changes by continuously varying the damping coefficients and force characteristics of the active shock absorbers based on detected vehicle state parameters. During cornering, the system modifies parameters such as damping force, compression resistance, and extension characteristics to optimize stability, using real-time adjustments to multiple parameters rather than single-parameter control.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If active shock absorbers make autonomous movements independent of road stresses, then dynamic performance and comfort improve, but the energy consumption and actuator complexity increase

Engineering Contradiction:
Improvedynamic performanceVSAvoidactuator energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies the anti-weight principle by using the active shock absorbers to generate counter-forces that oppose unwanted vehicle movements and road disturbances. The actuators produce forces that counteract the effects of road stresses, body roll, pitch, and yaw, effectively creating opposing forces that stabilize the vehicle while allowing autonomous movement control independent of direct road stress transmission.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

Data Source

PatentEP4101665B1Method to control the active shock absorbers of a road vehicle featuring the lowering of the centre of gravity
Publication Date: 2023.10.11 FERRARI SPA
  • EP4101665B1 patent drawingFigure 1
  • EP4101665B1 patent drawingFigure 2
  • EP4101665B1 patent drawingFigure 3

AI summary

Method to control active shock absorbers (6) of a road vehicle (1). Each active shock absorber (6) is part of a suspension (5) connecting a frame (4) to a hub (3) of a wheel (2) and is provided with an actuator (10). The control method comprises the steps of: determining a longitudinal acceleration (ax) and a transverse acceleration (ay) of the road vehicle (1); establishing a desired lowering (hb-TGT) of a centre (B) of gravity of the road vehicle (1) depending on the longitudinal acceleration (ax) and on the transverse acceleration (ay); and controlling the actuator (10) of each active shock absorber (6) so as to obtain the desired lowering (hb-TGT) of the centre (B) of gravity.