Patent Application
20070078575
The invention relates to marine vessel control systems.
In addition to forward and reverse, today's vessels, depending on the specific capabilities of their primary propulsory mechanism(s), employ thrust vector(s) for basic vertical axis pitch control and/or horizontal axis steering control. Today's primary propulsion vertical and horizontal axis thrust vectors exists as functionally independent nonintegrated forces, thus are ineffective when compared to their potential if fused together within an advanced synergistic vessel control system with fully-integrated primary propulsion attitude and steering authority. Today's vessels could realize significantly improved overall performance and stability, in all operating conditions, by employing coordinated, computer controlled dynamic thrust vector manipulation of their primary propulsory mechanisms.
Accordingly, the vessel control system of the present invention solves the limitations of typical marine vessel performance and stability with computer coordinated manipulation of one or more independently actuated and articulated primary propulsory thrust vectors resulting from dynamically changing the angle of the propulsory mechanism. Employing this novel system in a differential or asymmetric manner as an active method to control vessel attitude and stability, regardless of speed, is a highly efficient and practical method for maximizing the effectiveness of primary propulsion systems by much more effectively harnessing the thrust they generate.
Dynamic vector control can advantage and be effectively integrated with primary marine propulsion systems including, but not limited to, outboards, outdrives, sterndrives, waterjet drives, etc., in which the thrust vector resulting from the angle of the propulsory mechanism can, at a minimum, be vertically articulated to induce both positive and negative pitch trim. The resulting novel system, especially when combined with active differentially managed hydrofoil devices such as trim tabs, will maximize overall vessel responsiveness, maneuverability, stability, ride quality, attitude control, fuel economy, speed and safety.
Definitions
Differential and differentially are defined within this document as unequal, off center and/or involving differences in: angle, speed, rate, direction, direction of motion, output, force, moment, inertia, mass, balance, application of comparable things, etc.
Primary propulsion and primary propulsory are defined as the main thrust generating propulsion system(s), mechanism(s) and device(s) employed to propel a vessel throughout low, medium and high speed translation operations. Low-speed maneuvering thrusters and other similar secondary thrust generating devices do not apply to this specific definition.
Dynamic and dynamically are defined as immediate actions that take place at the moment they are needed; used in describing interactive hardware and software systems involving conflicting forces; characterized by continuous change and activity.
Vessel attitude is defined relative to three rotational axes: pitch attitude (rotation about the y or sway-axis); roll attitude (rotation about the x or surge-axis); yaw attitude (rotation about the z or heave-axis).
One or more primary propulsion devices are independently controlled by an intelligent vessel control system which is operable to dynamically manage thrust vector angle(s) in a differential or parallel manner, over the entire range of vessel performance and operation. The propulsory mechanisms, as a minimum, must be at least capable of vertical axis pitch articulation.
The intelligent vessel control system readily adapts to primary marine propulsion systems including outboards, outdrives, sterndrives, waterjet drives, etc., in which the thrust vector resulting from the angle of one or more primary propulsory mechanisms can, at a minimum, be vertically articulated in a dynamic manner to induce both positive and negative pitch trim. Coordinated dynamic manipulation of multiple, independently actuated and articulated thrust vectors resulting from changing the angle of the propulsory mechanism in a differential or asymmetric manner as an active method to control vessel attitude and stability, regardless of speed, is a novel approach for maximizing the effectiveness of primary propulsion systems by much more effectively harnessing the thrust they generate, as shown in
The vessel control system electronics package is a fully distributed automation and control system, integrating an intelligent central control computer package with vessel motion sensors and servo hydraulic control outputs, although other suitable actuation mechanisms can be utilized, providing real-time automatic integrated control of a vessel's main operating parameters. The central control computer executes ride control algorithms and coordinates system activity. Sensors located throughout a vessel transmit real-time motion data (attitude, rate, acceleration, etc.) to the central control computer. Additional sensors monitor exact positioning and condition of the vessel's individual operating parameter directly influenced by the vessel control system. This information is processed and precise instructions are communicated to individual servo controllers responsible for specific vessel operating parameters or effectors. Parameters such as individual thrust vector angle, thrust velocity, engine output, drive engagement and gear selection, trim tab deflection, rudder position, etc., are electronically monitored and controlled by the vessel control system and can be actuated hydraulically, electrically or with other suitable mechanisms. Some of the basic real-time performance capabilities of the vessel control system include: trim stabilization and pitch damping; list stabilization and roll damping; yaw damping and turn coordination, etc. An operator interacts with the vessel control system through a user interface which can employ a number of different electronic and/or mechanical control input and system monitoring devices such as: Graphical User Interface (GUI) displays and/or touch screens; gauge instruments; voice command and alert interfaces; joysticks; keyboards; steering wheels; throttles; switches; dials; etc. The user interface communicates the vessel control system's current operational status, current vessel setup, logged operational data, etc. Some of what the user interface allows the operator to do is: select automatic or manual operating modes; set the desired running trim and list of the vessel; increase or decrease the gain settings for pitch and roll control functions; select between flat and coordinated turns; etc.
For more advanced vessel integrations, control system software contains a thoroughly defined map of a specific hull form's drag characteristics based on attitude and displacement variables. The software forms part of the control logic for steering, stability, attitude, speed, acceleration and fuel economy. A series of prime directives, such as safety, stability and maximum fuel economy per speed condition are resident in the vessel control logic. As an operator or autopilot advances and retards throttle settings to affect speed, the vessel control system compares stored hull drag and displacement data to real-time information gathered by the onboard sensor package. This information is used to correct vessel attitude and displacement based on the resident control logic directives. A vessel's attitude can have a tremendous impact on its performance and efficiency during operation. Depending on vessel design and available equipment, control logic determines the combination of parameters or resources such as thrust vector angle(s), engine output, trim tab deflection, rudder position, ballast distribution, etc., necessary to maintain, optimize or achieve specific performance objectives. For example, with information acquired from an external GPS data source, an operator can identify a destination and desired arrival time while in route; control logic will select the best economy engines capable of maintaining the schedule, to include starting or pulling off-line powerplants the system determines either necessary or unnecessary for the defined mission; manage throttle settings and required speed; and steer the course either by conventional means utilizing a rudder, or with asymmetric drag and differential thrust vectoring and velocity.
Asymmetrical drag steering takes advantage of the vessel control system's ability to precisely control roll and, as a result, induce a turning moment by increasing wetted surface area asymmetrically on one side of the hull or the other. Just as drag increases with vessel speed, so does the turning force generated by differential lateral wetted surface area. Mapping the drag characteristics of a specific hull form based on pitch, roll and displacement variables is necessary to reliably predict the asymmetric influence and employ it as a practical steering system. In addition to asymmetrical drag steering, the vessel control system can integrate with, and electronically control, other steering devices such as conventional rudders, vectored thrust, steerable drives, etc.
Vessel control system integration with a resident thrust vectoring steer-by-wire capability allows for practical application of differential steering. Along with traditional course management, a differential capable thrust vectoring steer-by-wire system can be employed during certain maneuvers and/or conditions for desired effect. Example maneuvers are: controlled lists at idle forward progress; crabbing; lateral sway translation (sideways movement) without assistance from bow and/or stem thrusters; power-on breaking (accomplished by counter-rotating multi-propulsory mechanisms on their horizontal axis at a uniform rate in order to neutralize thrust forces until vector angles are pointing in the opposite direction of travel); drift control; etc. When integrated with a joystick or similar adequate operable device, an operator can easily maneuver a vessel in all directions at low speed for precision navigation in challenging low tide environments to convenient docking in congested areas.
The vessel control system has demonstrated maneuvers that are not known to have been accomplished prior. The first, a “flat turn”, is accomplished by instructing the vessel control system to maintain a neutral or level deck attitude while turning. The combination of differential vertical axis thrust vector authority and appreciable force imparted by the active differential trim tabs results in this capability. The byproduct of a “flat turn” is a significant reduction in wetted surface area as compared to what a similar vessel would experience as a result of leaning into turns and forcing a larger area of the hull into the water. Increasing wetted surface area for an extended period during a turn results in speed loss. The vessel control system eliminates leaning in turns and, as a result, does not experience the same level of speed loss. Another by product of the “flat turn”, is a significant reduction in turning radius. Current experience is as much as 50% turning radius reduction during testing.
Another capability of the vessel control system resulting from its differential thrust vector and active trim tabs is a reluctance to fishtail. Testing at speeds as high as 35 knots with hard entry into tight turns with full stop steering input could not break the test vessels stern loose.
Experience with the vessel control system's unique stability capabilities, inspired development of control logic for automated active roll-over prevention. The vessel control system is able to identify conditions whereby a vessel is exceeding specific design and/or safe operating limits with respect to stability. The vessel control system reacts irrespective of cause; operator error, hazardous environmental conditions, or otherwise. Active, dynamic countermeasures are employed by the vessel control system including, but not limited to, thrust vector and velocity manipulation, trim tab deflection, etc., in order to reestablish control of the vessel.
As shown in
The vessel control system supports integration with navigational and collision avoidance technologies, such as GPS, radar, downloadable satellite information, etc., in order to optimize the system's operational capabilities.
The vessel control system is capable of dynamically integrating hydrofoil and/or planing devices such as t-foils and tabs into a specific installation's overall stability, attitude and steering solution. For example, differentially articulated trim tabs can be used when controlling or dampening roll under certain conditions. The vessel control system determines based on the effectors at its disposal, which to deploy for a desired result. Per condition, control logic analyzes its options and deploys one or more selected mechanisms, differentially or in parallel, based on the most efficient method for achieving operator or autopilot directed objectives.
As shown in
The outboard motor is mounted to the mounting bar in a conventional manner. However, the length of the arm is such that the motor may be moved towards the transom a sufficient distance to permit the thrust vector created by the propeller shaft angle to move as much as 45 degrees undertrim from a horizontal position. In this way, the propellers or thrust vectors can be moved rapidly by the control system to stabilize the boat. The mount articulates in such a way as to maintain a near uniform thrust vector height relative to the horizontal plane of the vessel.
The vessel control system may be adapted to waterjet drives. This requires waterjet nozzles capable of both vertical axis pitch articulation and horizontal axis steering articulation. Referring to
The vessel control system, based on information received from an integrated depth finder or other similar suitable obstacle/terrain avoidance technology, can automatically raise/retract onboard propulsory mechanisms, overriding operator input and settings, when clearance becomes a concern; as would be the case in shallow water environments. For higher-speed operations, logic resident within the vessel control system identifies slope changes in underwater landmasses and predicts probable distance till drive strike based on the relationship between speed, slope and drive depth. The vessel control system automatically lowers/extends the propulsory mechanism(s) to normal operating position(s) once a safe environment signal is received.
The invention has been described in an illustrative manner. It is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than limitation. Many modifications and variations of the invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the invention may be practiced other than as specifically described.
This application claims priority of U.S. Patent Provisional Applications No. 60/693,284 filed Jun. 23, 2005 and 60/749,820, filed Dec. 13, 2005 which are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60693284 | Jun 2005 | US | |
| 60749820 | Dec 2005 | US |
