GB2512865A

GB2512865A - Marine vessel dynamic positioning control system

Info

Publication number: GB2512865A
Application number: GB1306405.0A
Authority: GB
Inventors: Christopher Shane Huxley-Reynard
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-04-09
Filing date: 2013-04-09
Publication date: 2014-10-15
Also published as: GB201306405D0

Abstract

The manual controls 1-5 onboard a marine vessel normally used by the helmsman to control the vessel propulsion and steering systems are driven by a set of mechanical actuators 6-9, 14 under the control of a control system. The control system may be retrofitted to existing manual controls. The control system controls the vessel position and/or heading in a manner similar to that of a conventional dynamic positioning control system.

Description

tM:;: INTELLECTUAL S... * PROPERTY OFFICE Application No. tJB13064O5.0 RTM Date:31 July 2013 The following terms are registered trademarks and should be read as such wherever they occur in this document: Kongsberg Raymarine Intellectual Properly Office is an operaling name of Ihe Patent Office www.ipo.gov.uk

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Marine vessel dynamic Dositioning control system

Background

There is an increasing trend towards the use of dynamic positioning control systems on commercial and leisure craft. Such dynamic positioning systems allow a vessel to hold position and heading using its propulsion and steering systems without the need to moor. The main controller employed in a dynamic positioning control system is typically a computer, micro-controller, PLC or equivalent. The main controller interacts electrically with the propulsion and steering systems, sending them demand signals (for example demand rotational speed of a propeller) and getting back feedback signals via instrumentation (for example current angle of a rudder). When the dynamic positioning control system is actively controlling the vessel position and/or heading, the manual controls at the helm of the vessel are typically disabled so that there is no conflict between manual versus computer control of the vessel. The helmsman may de-activate the dynamic positioning control system and revert to manual control, whereby the manual controls at the helm of the vessel become active again.

In the case of a newly built ship that is installed with a dynamic positioning control system the above system architecture works well, since it is possible to design the propulsion and steering systems to interface with both the dynamic positioning control system and the helm manual controls from the outset.

In the case where a dynamic positioning control system is being retro-fitted to an existing vessel, particularly one that was originally designed only to be controlled manually, such an installation can be problematic and expensive.

Such a vessel might employ a series of manual controls such as levers, buttons, dials, sliders switches etc fitted at the helm to control the propulsion and steering systems. The existing interfaces between the helm manual controls and the propulsion and steering systems may not be compatible with the new dynamic positioning control system. It may be costly in terms of additional hardware and engineering effort to modify these interfaces to work under both manual and dynamic positioning control. Any such modifications to the ships systems may also invalidate the certification / warranty of these systems.

The present invention seeks to provide a cost effective means of providing dynamic positioning capability on existing vessels with manual controls.

Prior Art

Kongsberg oiler a range of dynamic positioning control systems for marine vessels. These control systems allow vessel position and/or heading to be controlled to a high degree of accuracy using the propulsion and steering systems onboard the vessel, taking inputs from various external sensors such as a global positioning system, wind anemometer, pitch and roll sensors etc. The dynamic positioning system controls the ship propulsion and steering systems via electrical interfaces between the dynamic positioning system main controller and the propulsion and steering systems, bypassing the manual controls normally used by the helmsman. When the helmsman wishes to control the vessel in manual mode, the dynamic positioning controller returns control authority to the manual controls.

The Autohelm system (trademark of Raymarine) actuates a boat's tiller by means of a linear actuator to control the vessel course. The system is designed to drive just a rudder and cannot be used for dynamic positioning.

The linear actuator drives the tiller directly as opposed to driving a control lever located at the helm which would in turn control the rudder remotely via an actuator.

The Trimble AgGPS EZ-Steer uses a GPS position reference to drive the steering column on an agricultural tractor by means of a rotary actuator acting on the steering wheel. Such prior art is designed to achieve a different function in a different application, but illustrates the concept of using a mechanical actuator to drive a manual control (in this case the steering wheel).

Statement of the invention

The present invention seeks to provide dynamic positioning capability to a marine vessel whilst seeking to overcome the disadvantages associated with retro-fitting a new dynamic positioning control system to a vessel with existing propulsion and steering systems and manual controls.

The proposed invention comprises a series of mechanical actuators that physically operate the existing manual controls at the helm of the vessel, in conjunction with a control system to control the vessel in the manner of a conventional dynamic positioning system. The control system takes inputs from multiple sensors onboard the vessel (eg Global Positioning System, wind anemometer etc) and supplies the required demands to the propulsion and steering systems by actuating the manual controls on the vessel via the mechanical actuators. Feedback from the propulsion and steering systems to the control system is provided either via existing instrumentation onboard the vessel, or via additional instrumentation that is fitted for this purpose.

A range of different types of mechanical actuators may be provided to operate different types of manual controls. In some cases a mechanical actuator with multiple degrees of freedom may be required to operate a particular manual control (eg a joystick). Some examples of manual controls and mechanical actuators are listed below though it will be appreciated to someone experienced in the art that this list is not exhaustive: Types of manual control that could be present at the helm: * Lever (eg simple engine RPM control) * Joystick (eg azimuth thruster RPM and direction control) * Pushbutton switch (eg bow thruster control) * Toggle switch (eg rudder control) * Slider (eg rudder control) * Dial (eg bow thruster control) * Keypad * Touchscreen Types of mechanical actuator that could operate the manual controls: * Single linear actuator (eg pneumatic ram or electric solenoid) * Single rotary actuator (eg pneumatic vane motor or electric stepper motor) * Multiple linear actuators (eg two pneumatic rams to drive a 2 degree of freedom joystick) * Multiple degree of freedom robot arm driven by rotary and/or linear actuators (eg to operate a touchscreen) In one embodiment of the invention the mechanical actuators can be mechanically disconnected / removed from the manual controls in order that the helmsman can quickly regain manual control of the vessel.

In another embodiment of the invention one or more of the mechanical actuators incorporates a normally locked hinge linkage or mechanical slider that can be un-locked by the helmsman, such a feature allowing the mechanical actuator to remain attached to the manual control whilst offering minimal physical resistance to the helmsman who again may wish to quickly regain manual control of the vessel.

In another embodiment of the invention, when a switch or equivalent device is selected some or all of the actuators may be back-driven (ie not provide excessive mechanical resistance to a force applied to the manual control by the helmsman). Such an embodiment would again allow the helmsman to control the vessel manually using the manual controls without removing or altering the mechanical actuators. Such an embodiment might be achieved through the use of pneumatic actuators with a relief valve that was vented to atmosphere for manual control mode such that the pneumatic actuators provided minimal mechanical resistance.

Advantages The proposed invention has the following principal advantages: -Significant time and cost can be saved when fitting a dynamic positioning control system to an existing vessel. This is due to minimal (or no) re-engineering required on the existing electrical interfaces to the vessel propulsion and steering systems.

-Lower risk of system failure in all control modes (whether under control of the dynamic positioning controller or manual control), since there have been minimal or no changes/additions to the existing ship systems.

-Existing warranties/certification for ship propulsion and steering systems may be maintained since these systems have not been significantly modified.

Introduction to drawings

Figure 1 shows a typical set of manual controls laid out at the helm of a marine vessel having a bow thruster, two main propellers and a rudder. The bow thruster is operated via two push buttons (1) and (2), driving it to port and starboard respectively. The port and starboard propellers are each operated by control levers (3) and (4) respectively. The helmsman pushes each lever away from him to drive the propeller ahead and pulls it towards him to drive the propeller astern. The rudder is driven by lever (5). Pushing the lever to the left actuates the rudder to port and pushing it to the right actuates the rudder to starboard. No mechanical actuators have yet been fitted to the manual controls shown in Figure 1.

Figure 2 shows the same set of manual controls as shown in Figure 1 but with mechanical actuators fitted. The push buttons (1) and (2) for the bow thruster can be pushed by the pair of solenoids (6) and (7) respectively. The propeller levers (3) and (4) can be controlled via a pair of double acting pneumatic rams (8) and (9) respectively. These rams are connected to the propeller levers via flexible couplings (10) and (11) and to the helm dashboard by mounts (12) and (13). The lever for the rudder (5) can be actuated by a rotary motor (14) via a belt (15) which acts upon a sprocket (16) fitted to the top of the lever for the rudder (5).

It shall be appreciated to someone experienced in the art that many such combinations and variations of mechanical actuators are possible to drive different types of manual controls, and all such combinations and variations are considered to fall within the scope of this invention.

Claims

C/aims 1. A marine vessel dynamic positioning system comprising: mechanical actuators disposed to operate the manual controls onboard a marine vessel in place of the helmsman, in order to control the vessel propulsion and/or steering systems; a control system controlling said mechanical actuators; a control method permitting the vessel position and/or heading to be controlled in a prescribed manner such as that typically seen on ship dynamic positioning systems, such systems being familiar to persons experienced in the art.
2. A marine vessel dynamic positioning system as claimed in claim 1 wherein the vessel' s propulsion and steering systems comprise any combination of fixed direction thrusters, controllable azimuth direction thrusters, rudders, rudder propellers, stabilisers, horizontal axis thrusters, vertical axis thrusters and any other propulsion or steering systems known to persons experienced in the art.
3. A marine vessel dynamic positioning system as claimed in any previous claim wherein the manual controls on the vessel comprise any combination of levers, switches, sliders, dials, joysticks, keypads and touchscreens.
4. A marine vessel dynamic positioning system as claimed in any previous claim wherein the mechanical actuators comprise any combination of linear or rotary actuators, such actuators being driven by any means including electrically, hydraulically, pneumatically and magnetically.
5. A marine vessel dynamic positioning system as claimed in any previous claim wherein the control system uses inputs from one or more external sensors for the purposes of determining the current vessel position and orientation, the current external environmental conditions and/or the current status of the vessel propulsion and steering systems, such data being used to assist the control system in actively controlling the position and/or heading of the vessel.
6. A marine vessel dynamic positioning system as claimed in any previous claim wherein one or more of the manual controls relays its demand signal to the propulsion and/or steering systems either electrically, pneumatically, hydraulically or magnetically.
7. A marine vessel dynamic positioning system as claimed in any previous claim wherein control of the vessel propulsion and/or steering systems can be switched between the control system and helmsman control, whereby helmsman control allows the helmsman to operate the manual controls substantially as he would do if the dynamic positioning system was not present.
8. A marine vessel dynamic positioning system as claimed in claim 7 wherein one or more mechanical actuators can be back-driven under the action of the helmsman applying force to the particular mechanical actuator/s, such provision being made to allow quick changeover from control system control to helmsman control.
9. A marine vessel dynamic positioning system as claimed in claim 7 wherein one or more mechanical actuators can be physically disconnected from the manual control/s by means of a quick-release mechanism, such provision being made to allow quick changeover from control system control to helmsman control.
1O.A marine vessel dynamic positioning system as claimed in claim 7 wherein one or more mechanical actuators can be configured to mechanically float relative to the manual control/s to which it is connected, such provision being made to allow quick changeover from control system control to helmsman control.
11.A marine vessel dynamic positioning system substantially as claimed and described herein.