Watercraft Roll Damping via Thrust Vectoring

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Solution Overview

Problem

Existing methods for damping the rolling movement of watercraft are limited to specific drive designs, such as Voith-Schneider propellers or structurally complex systems, and often worsen flow around the fuselage or require excessive mechanical stress.

Innovation Solution

A method that uses drives pivotable about the vertical axis, such as rudder propellers or pump jets, to generate a transverse force by adjusting the thrust vector's direction, counteracting rolling movements through calculated damping angles, which can be determined by control devices using measured variables and algorithms, including self-learning systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If positioning drives are activated during en-route cruising to dampen roll motion, then roll damping is achieved, but airflow around the fuselage is significantly impaired

Engineering Contradiction:
Improveroll stabilityVSAvoidairflow impairment
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The invention merges the roll damping function with the existing propulsion system by utilizing the propeller thrust vector for both forward propulsion and roll damping. The propeller is pivoted about the vertical axis to generate a transverse force component that dampens roll while maintaining propulsion, eliminating the need for separate positioning drives and avoiding airflow impairment to the fuselage.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The propulsion system is given multiple functions: it provides both forward thrust and roll damping. By pivoting the propeller about the vertical axis, the same drive generates both the propulsive force in the direction of travel and the transverse force for roll stabilization, making the system universal and avoiding additional structures that would interfere with airflow.

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

2Stability of the object's composition

If additional pivoting around a horizontal axis is implemented for roll damping, then roll damping is achieved, but structural complexity increases

Engineering Contradiction:
Improveroll stabilityVSAvoidstructural complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The invention combines roll damping with the existing vertical axis pivoting capability of the propulsion system. Instead of adding a separate horizontal axis pivoting mechanism, the propeller is pivoted about the vertical axis to generate transverse force for roll damping, thereby avoiding additional mechanical complexity while achieving the same stabilizing effect.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention extracts the roll damping function from complex mechanical pivoting systems and implements it through thrust vectoring of the existing propulsion system. By using the propeller's thrust direction control to generate roll-damping transverse forces, the solution eliminates the need for additional mechanical structures and simplifies the overall system.

Inventive Principle:
Principle #2Taking out (Extraction)

3Stability of the object's composition

If the drive is pivoted from the predetermined steering angle by a damping angle, then roll damping is achieved, but propulsion efficiency is reduced

Engineering Contradiction:
Improveroll stabilityVSAvoidpropulsion efficiency
Core Design Contradiction:
Stability of the object's compositionVSUse of energy by moving object

Solution Approach 1:

The propeller is pivoted periodically about the vertical axis in synchronization with the roll period of the watercraft. The damping angle is applied only during specific phases of the roll cycle when it is most effective for damping, rather than continuously. This periodic application minimizes the impact on propulsion efficiency while achieving effective roll stabilization.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The damping angle is applied partially - only during specific phases of the roll cycle and only to the extent necessary for effective damping. The control system calculates the optimal damping angle based on measured roll parameters, applying just enough transverse force to dampen roll without excessively deviating from the optimal propulsion direction, thereby minimizing energy loss.

Inventive Principle:
Principle #16Partial or excessive action

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 dampens rolling movements across various drive designs, reducing power consumption and mechanical stress while maintaining propulsion and steering capabilities, and can be applied to both underway and dynamic positioning modes.

Implementation Method 1

the drive for generating a thrust jet for the watercraft is pivotable about the vertical axis of the watercraft and is pivoted about the vertical axis to a steering angle according to a control system

Methodology Applied
Scientific EffectThrust vectoring: Jet

Implementation Method 2

a damping angle is calculated, which is superimposed on the steering angle of the at least one drive. The drive is pivoted from the predetermined steering angle by the damping angle to generate the transverse force about the vertical axis, such that the steering angle is increased or decreased by the damping angle during a rolling period of the watercraft

Methodology Applied
Scientific EffectTorque generation: Torque

Data Source

PatentEP3321163B1Method for damping the roll movement of a watercraft
Publication Date: 2020.03.11 SCHOTTEL
  • EP3321163B1 patent drawingFigure 1~2

AI summary

The invention relates to a method for damping the rolling movement of a watercraft (1) about its longitudinal axis (L), wherein the watercraft (1) has at least one drive for generating a thrust jet for the watercraft (1), in which at least one measured variable characterizing the rolling movement is measured and, depending on the measured variable, a transverse force counteracting the rolling movement is generated, in which the drive and the generated thrust jet can be pivoted about the vertical axis of the watercraft (1) and is pivoted into a steering angle in accordance with a control and, depending on the measured variable, is pivoted from the predetermined steering angle by a damping angle (D) to generate the transverse force.