Vessel Suspension Attitude Control with Variable Pitch-Roll Stiffness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing suspension systems for vessels fail to efficiently adjust the pitch and roll attitude of the body or chassis relative to movable hulls, lacking in efficiency and requiring alternative mechanisms for improved control.
Innovation Solution
A suspension system with locating arrangements, damper rams, and a deck attitude control system that includes sensors and actuators to control the attitude of the chassis relative to the hulls, allowing for reduced or removed roll and pitch stiffness while maintaining heave stiffness, using interconnected damper rams and a controller to manage fluid pressures and flows.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional suspension systems are used to control pitch and roll attitude, then attitude control is achieved, but the system complexity and inefficiency increase
Solution Approach 1:
The suspension system employs actively controllable dampers with variable stiffness characteristics that can dynamically adjust between soft and stiff states based on operational requirements, enabling efficient attitude control while simplifying system architecture through adaptive rather than static design
Solution Approach 2:
The system changes the stiffness parameter of the dampers on-demand, transitioning from fixed stiffness to variable stiffness configuration, allowing the same physical system to perform multiple functions (attitude control and simplification) by altering its mechanical properties rather than adding complex control mechanisms
2Ease of operation
If roll and pitch stiffness is maintained in supports, then structural stability is provided, but the ability to control deck attitude independently is reduced
Solution Approach 1:
The support structures incorporate dampers with dynamically adjustable stiffness, allowing the system to transition between providing structural stability (stiff state) and enabling independent deck attitude control (soft state), thus resolving the contradiction between maintaining stability and achieving control flexibility
Solution Approach 2:
The system periodically adjusts the stiffness of support dampers based on operational phase, being stiff during transit for stability and soft during docking operations for precise attitude control, thereby achieving both structural stability and control capability at different times
3Measurement precision
If multiple actuators and sensors are added for precise attitude control, then control precision is improved, but system complexity increases
Solution Approach 1:
The damper assemblies serve multiple functions simultaneously: they provide structural support, act as damping elements, and function as controllable actuators for attitude adjustment, eliminating the need for separate actuators and sensors while maintaining precise control capability
Solution Approach 2:
The system uses the existing mechanical components (dampers and supports) to perform both structural and control functions, allowing these components to serve themselves rather than requiring additional dedicated control hardware, thus improving precision without increasing overall system complexity
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 effectively controls the attitude of the vessel's chassis, minimizing lateral and vertical displacement, enhancing stability during docking and transit, and simplifying the control process by reducing roll and pitch stiffness when needed.
Implementation Method 1
at least a front left and back left damper ram connected between the chassis portion and longitudinally spaced points on the at least one left hull, at least a front right and back right damper ram connected between the chassis portion and longitudinally spaced points on the at least one right hull
Implementation Method 2
Adjustments to the fluid in the hydraulic circuits is discussed for controlling the height and orientation of the chassis portion and of the hulls
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A suspension system for a vessel (1) having at least one left hull (11), at least one right hull (12) and a chassis portion (10), the suspension system including supports (20) for at least partially supporting the chassis portion relative to the left and right hulls, and a front left and back left damping ram (31, 33) connected between the chassis portion and longitudinally spaced points on the at least one left hull, a front right and back right damping ram (32, 34) connected between the chassis portion and longitudinally spaced points on the at least one right hull. The suspension system further includes a deck attitude control system (250) comprising a controller (252), sensors, and a respective actuator arrangement for each of at least two orthogonally spaced damper rams. The actuators control a position of at least one point on the chassis relative to at least one reference.