Active Boat Suspension for Deck Heave Isolation

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Solution Overview

Problem

Existing boat suspension systems fail to effectively maintain a constant deck height and isolate occupants from all degrees of motion, particularly heave, leading to sea sickness and discomfort.

Innovation Solution

A boat suspension system that separates the deck from the hull using active suspension systems between a frame and pontoons, employing a four-bar mechanical linkage and air springs with servo motors to maintain a constant deck height and isolate motion, powered by batteries for extended operation without noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If passive dampening systems (springs, shock absorbers) are used to reduce pitch and roll motion, then comfort in horizontal stability is improved, but the ability to maintain constant deck height (heave isolation) is lost

Engineering Contradiction:
Improvehorizontal stability (pitch and roll dampening)VSAvoidheave motion transmission to occupants
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The patent replaces traditional passive mechanical dampening systems with an active control system using electrohydraulic actuators. These actuators actively adjust the suspension geometry in real-time to counteract wave-induced motions, providing both pitch/roll dampening and heave isolation that passive springs and shock absorbers cannot achieve alone.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The suspension system transitions from static passive elements to dynamic active components. The electrohydraulic actuators continuously adjust suspension characteristics based on real-time motion sensing, enabling the system to adapt to varying sea conditions and maintain optimal performance across different motion axes including heave, pitch, and roll.

Inventive Principle:
Principle #15Dynamics

2Object-affected harmful factors

If active control systems with multiple actuators are implemented to maintain constant deck height, then heave isolation is improved, but device complexity increases

Engineering Contradiction:
Improveheave motion isolationVSAvoidsuspension system complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The electrohydraulic actuators serve multiple functions simultaneously: they control ride height, dampen pitch motion, dampen roll motion, and provide heave isolation. This multi-functionality reduces the need for separate dedicated components for each function, thereby managing system complexity while achieving comprehensive motion control.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system incorporates motion sensors that continuously monitor deck acceleration and position, feeding this data back to the control system. The control system processes this feedback and adjusts actuator commands in real-time, creating a closed-loop control system that maintains constant deck height while adapting to changing sea conditions without requiring overly complex open-loop control mechanisms.

Inventive Principle:
Principle #23Feedback

3Force

If traditional shock absorption systems are used to cushion deck movement, then pitch and roll dampening is improved, but the ability to provide significant vertical travel while maintaining deck height is lost

Engineering Contradiction:
Improveshock absorption capabilityVSAvoidvertical travel range
Core Design Contradiction:
ForceVSLength of moving object

Solution Approach 1:

The suspension system employs dynamically adjustable electrohydraulic actuators that can vary their stroke length and damping characteristics in real-time. This allows the system to provide significant vertical travel when needed (such as when navigating large waves) while maintaining constant deck height through active control, overcoming the fixed limitations of traditional shock absorbers.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The suspension system is divided into multiple independent actuator assemblies, each capable of independent adjustment. This segmentation allows different parts of the suspension to operate at different strokes and damping levels simultaneously, providing both the vertical travel needed for wave accommodation and the precise control needed for deck height maintenance.

Inventive Principle:
Principle #1Segmentation

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

The system provides significant vertical travel and frequency response to accommodate wave motion, reducing sea sickness and maintaining a level deck, with minimal power consumption and noise, effectively addressing the limitations of prior art by isolating occupants from all directional motions.

Implementation Method 1

employing a four-bar mechanical linkage and air springs with servo motors to maintain a constant deck height

Methodology Applied
Scientific EffectAir spring: Spring

Implementation Method 2

employing a four-bar mechanical linkage and air springs with servo motors to maintain a constant deck height

Methodology Applied
Scientific EffectServo motor: Linear Motor

Data Source

PatentEP3564116B1Boat with active suspension system
Publication Date: 2021.03.31 VELODYNE ACOUSTICS INC
  • EP3564116B1 patent drawingFigure 1
  • EP3564116B1 patent drawingFigure 2
  • EP3564116B1 patent drawingFigure 3

AI summary

A boat having a deck and a hull includes a suspension for suspending the deck with respect to the hull. Sensors are employed to determine motion of the deck, with a controller adjusting the suspension such that it maintains the pose of the deck with respect to an inertial reference and with respect to pitch, roll, and heave of the deck.