CA2171885A1 - Automatic control system in a ship provided with rotatable propeller devices - Google Patents
Automatic control system in a ship provided with rotatable propeller devicesInfo
- Publication number
- CA2171885A1 CA2171885A1 CA002171885A CA2171885A CA2171885A1 CA 2171885 A1 CA2171885 A1 CA 2171885A1 CA 002171885 A CA002171885 A CA 002171885A CA 2171885 A CA2171885 A CA 2171885A CA 2171885 A1 CA2171885 A1 CA 2171885A1
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- Canada
- Prior art keywords
- ship
- propeller devices
- pair
- propeller
- angle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000012423 maintenance Methods 0.000 claims abstract description 4
- 230000008901 benefit Effects 0.000 description 7
- 230000000694 effects Effects 0.000 description 4
- 230000001105 regulatory effect Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H25/00—Steering; Slowing-down otherwise than by use of propulsive elements; Dynamic anchoring, i.e. positioning vessels by means of main or auxiliary propulsive elements
- B63H25/42—Steering or dynamic anchoring by propulsive elements; Steering or dynamic anchoring by propellers used therefor only; Steering or dynamic anchoring by rudders carrying propellers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H25/00—Steering; Slowing-down otherwise than by use of propulsive elements; Dynamic anchoring, i.e. positioning vessels by means of main or auxiliary propulsive elements
- B63H25/02—Initiating means for steering, for slowing down, otherwise than by use of propulsive elements, or for dynamic anchoring
- B63H25/04—Initiating means for steering, for slowing down, otherwise than by use of propulsive elements, or for dynamic anchoring automatic, e.g. reacting to compass
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H5/00—Arrangements on vessels of propulsion elements directly acting on water
- B63H5/07—Arrangements on vessels of propulsion elements directly acting on water of propellers
- B63H5/125—Arrangements on vessels of propulsion elements directly acting on water of propellers movably mounted with respect to hull, e.g. adjustable in direction, e.g. podded azimuthing thrusters
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- Ocean & Marine Engineering (AREA)
- Control Of Position, Course, Altitude, Or Attitude Of Moving Bodies (AREA)
- Control Of Vehicle Engines Or Engines For Specific Uses (AREA)
Abstract
An automatic control system for a ship with rotatable propeller devices for automatic maintenance of the course of the ship and for controlling the course in accordance with a preset course. The ship is provided with one or more pairs of propeller devices whereby the propeller devices that constitute a pair are arranged symmetrically in relation to a longitudinal center line of the ship and are connected to a central unit of the automatic control system, which central unit can be connected optionally to control the propeller devices that form a pair either in a symmetric mode of operation or in an asymmetric mode of operation. The automatic control system is provided with a control unit such that irrespective of the situation of operation of the central unit of the automatic control system, the propeller devices that form a pair can stick out by turning the propeller devices in opposite directions in relation to the longitudinal center line of the ship so as to regulate the speed of the ship.
Description
AUTOMATIC CONTROL SYSTEM FOR A
SHIP WITH TURNABLE PROPELLER DEVICES
FIELD OF THE INVENTION
The present invention relates to an automatic control system for a ship provided with turnable propeller devices for automatic maintenance of the course of the ship and for controlling the course of the ship in accordance with, or in conformity with, a preset course. The ship is provided with one or more pairs of propeller devices whereby the propeller devices that constitute each pair are arranged symmetrically in relation to the longitudinal center line of the ship and are connected to a central unit of the automatic control system. The central unit can be connected optionally to control the propeller devices that form a pair either in a symmetrical mode of operation or an asymmetrical mode of operation.
BACKGROUND OF THE INVENTION
Automatic control is used in ships for automatic maintenance of the course and for automatic control of the course of the ship in compliance with a preset course. Automatic control is used both in ships provided with rotatable propeller devices and in so-called conventional ships which are steered by means of a rudder. The conduct of ships provided with rotatable propeller devices, however, differs considerably from that of ships provided with a rudder. For this reason, the principles of control of the automatic control in these ships also significantly differ from one another. In this connection, a rotatable propeller device is understood as meaning, for example, such propeller devices rotatable ~_ ~171885 around a vertical shaft through 360 as described in the prior art, for example, in published patents and patent applications such as Finnish Patent Application No. 830373, which corresponds to U.S. Patent No. 4,573,929, Finnish Patent Application No. 853173, which corresponds to Great Britain Patent No. 2,179,312, Finnish Patent No. 79,991, which corresponds to Canadian Patent No. 1,283,004, and Finnish Patent No. 82,007, which corresponds to Canadian Patent No. 1,314,440.
The properties of the rotatable propeller devices include the generation of the force needed for both pushing and steering the ship. In normal ship applications, the ship has two rotatable propeller devices which are used in route navigation for steering the ship.
Of course, there are also other applications, in which the number of the propeller devices is different than two, most likely greater than two, but generally automatic control is used for the control of one or two propeller devices.
In a ship, the propeller devices each have control systems of their own, which systems control both the thrust and the turning angle of the respective propeller device under manual control. The automatic control, i.e., the "autopilot", gives the propeller device control system a request concerning a change in the course, which request is converted by the control system to a turning angle of the propeller device, and possibly an adjust in the thrust. In the conventional prior art control systems, the operator switches on the automatic control so that he manually selects the automatic control to control either the left propeller device or the right propeller device or both of them at the same time.
One of the major problem encountered in these prior art systems occurs in the situations of operation in which the automatic control is switched to control either one, the left or the right one, of the propeller devices. When the propeller device that is subjected to automatic control is placed at the side of the outside curve during a change in the course, the running of the curve itself is usually successful. The problem arises when the automatic control attempts to adapt the course of the ship after the curve to the instruction given, i.e., when the course is aligned after the curve. Then, the setting is not always successful, but the operator has had to bring the ship to the correct course by choosing the automatic control either for the propeller device at the inside curve or for both of the propeller devices. Even this has not been enough in all situations, but sometimes, in aligning the ship after the curve, it has been necessary to use manual control.
In order to solve the control problem described above and avoid manual control, the assignee's earlier Finnish Patent No. 92,378, which corresponds the Great Britain Patent No. 2,259,490, describes a novel automatic course control for a ship provided with rotatable propeller devices, in which ship the propeller devices are arranged as a symmetric pair of propeller devices, i.e., symmetrically arranged with respect to a longitudinal center line of the ship, and connected to the central unit of the automatic control, which unit can be connected optionally to control either one or both of the propeller devices that constitute a pair. According to this prior art system, when both propeller devices are connected to the automatic course control, the automatic control shifts the control devices of the propeller devices to an asymmetric state of operation, in which case, when the automatic control gives a command to make a curve, the automatic control always selects the propeller device at the side of the inside curve for the propeller ~17188~
device that turns the ship. In this case, the force that turns the ship remains sufficient. By means of this arrangement, compared with the prior art systems, remarkable improvements and advantages are obtained, the most important advantage being the fact that the force that turns the ship is also maintained in difficult situations of aligning the ship after a curve.
Further, by means of this arrangement, compared with conventional control systems, a more agreeable conduct of the ship was achieved, because the operation of the control was "smooth" .
However, in certain particular situations, also in the system described in Fl Patent No. 92,378, a certain problem occurred. This problem is manifested in particular in slow running speed and at very low travel speeds. Such very low travel speeds must be used, e.g., during various rescue operations, when collecting oil, when keeping the ship immobile, etc. Very low running speeds are, of course, achieved by reducing the speed of rotation of the propellers, but in such a case, the steering capacity of the ship is also lowered because the thrust curve of the propeller is lowered in proportion to the second power. Further, in the ships it is not possible to lower the speed of rotation of the propeller below the minimum speed of rotation of the propeller. For example, collecting oil requires a speed of about 1.5 knots, and in order that this speed could be reached by lowering the speed of rotation of the propeller alone, in quite a number of cases it would be necessary to go to a speed of rotation of the main engine below its minimum speed of rotation. Thus, at these low travel speeds, it has not been possible to use the automatic control system, but it has been necessary to control the ship manually. Manual control at low speeds is, however, very laborious and moreover, quite inaccurate. For this reason, it would be desirable to be able to use the automatic control of the ship also at such low running speeds.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide an automatic control system for a ship having propeller devices which efficiently operates at low travel speeds of the ship.
It is another object of the invention to provide a new and improved automatic control system for a ship including propeller devices in which the specific problem related to the automatic steering of a pair of propeller devices after a curve has been eliminated.
It is yet another object of the invention to provide a new and improved automatic control system for a ship including propeller devices in which the conduct of the ship is smooth during course maneuvers, most particularly during and after curves.
In view of achieving the objects of the invention described above and others, the present invention is mainly characterized in that the automatic control system is provided with a control unit by whose means, irrespective of the situation of operation of the central unit of the automatic control system, the propeller devices that form a pair can be connected to stick out by turning the propeller devices in opposite directions in relation to the longitudinal center line of the ship so as to regulate the speed of the ship. Thus, at a fixed rotational speed of the propellers, it is possible to both varying the speed of the ship as well as to engage in steering maneuvers. In this case, the rotational speed of the propellers can be maintained at a level at least as high as the minimum output speed of the engines while the speed of the ship can be very low to enable the ship to engage in, 217188~
e.g., rescue operations, oil collecting operations, and other operations which require very low speeds and still provide the ship with steering capabilities.
Compared with the prior art control systems, by means of the present invention a number of remarkable advantages are obtained, of which the following are described herein. The most important and the most significant advantage of the invention is expressly the fact that automatic control can be used at low travel speeds. In the manner suggested in the invention, efficient steering is also obtained at low speeds, because the speed of rotation of the propellers does not have to be lowered to a very low level, in which case the thrust of the propeller remains good and, as a result thereof, the steering capacity of the ship's control system is also good. If necessary, the propeller powers can be even increased in order to intensify the steering. When operating in ice, the propeller devices can be used for clearing a furrow in the ice by turning the propeller devices to a positive sticking-out angle and by directing strong propeller currents to the sides of the ship.
It is a further remarkable advantage of the invention that the invention can be carried into effect in existing control systems in a very simple way with a little modification.
The present invention thus comprises first steering control means coupled to at least one pair of propeller devices for individually determining a first angle of operation for each of the propeller devices to control the course of the ship and second speed regulation control means coupled to the propeller devices for determining a second thrust angle for both of the propeller devices independent of the determined first angle of operation of each of the propeller devices. The second thrust angle of each of the propeller devices is an angle defined between the longitudinal center line of the ship and a direction of thrust of a respective one of the propeller devices. The propeller devices are turnable in opposite directions so as to regulate the speed of the ship. Further, the system includes means for turning each of the propeller devices to a third angle which constitutes a combination of the second angle and a respective one of the first angles.
In certain embodiments, the first control means are separate from the second control means while in other the hrst control means comprises an automatic control central unit and the second control means are integrated in connection with the central unit such that turning of each of the propeller devices to the third angle is carried out as an internal operation in the central unit. The turning means are structured and arranged to turn the propeller devices to a positive second thrust angle in which the direction of thrust of the propeller devices are turned away from each other or to a negative second thrust angle in which the direction of thrust of the propeller devices are turned toward each other. The second control means can continuously determine the second angle of the propeller devices as a function of the desired speed of the ship such that the third angle is continuously adjusted accordingly.
In other embodiments, the second control means determine a value of the second angle of the propeller devices within a range from about 0 to about 180 in relation to the longitudinal center line of the ship. The second control means may also continuously determine the second angle of the propeller devices as a function of the desired speed of the ship, whereby the rotational speed of the propeller is constant, and the propeller devices are turned by the turning means to the third angles accordingly to maintain the desired speed of the ship and/or to keep the speed of the ship substantially constant.
21~1885 Further advantages and characteristic features of the invention will come out from the following detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The following drawings are illustrative of embodiments of the invention and are not meant to limit the scope of the invention as encompassed by the claims.
Figures 1A, 1B, 1C and 1D are schematic illustrations of the formation of the sticking-out angle of the propeller devices while the ships runs straight in a forward direction.
Figures 2A, 2B and 2C illustrate various modes of steering in accordance with the invention in situations of "sticking-out" of the propeller devices.
Figure 3 is a schematic illustration of an embodiment of the invention in which a negative sticking-out angle is used in the control of the propeller devices.
Figure 4 is a schematic illustration of an embodiment of the invention in which the propeller devices are placed at the fore of the ship.
Figure 5 is a fully schematic illustration of a ship control system in accordance with the invention in the form of a block diagram.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the accompanying drawings wherein the same reference numerals refer to the same or similar elements, as stated above, the present invention incorporates details of the assignee's Fl Patent No. 92,378 of earlier date, which relates to automatic 2171~8~
_ course control in a ship provided with rotatable propeller devices. However, by means of the present invention, the speed of the ship can be regulated by means of an automatic control device in combination with the course control in accordance with Fl 92,378. In the present invention, the possibility of regulating the speed of the ship is accomplished so that, in the ship, the propeller devices that constitute a pair are turned towards each other, i.e., so as to stick out, in order to reduce the speed of the ship. This is illustrated by way of example in Figs. 1A, 1 B, 1 C and 1 D, wherein the ship is denoted by reference S, the longitudinal center line of the ship is denoted by reference L, the propeller devices are denoted by reference numerals 1 and 2, and the "stick-out" angle or thrust angle of the propeller devices in relation to the longitudinal axis of the ship is denoted by the reference a. In Figs. 1A, 1B, 1C and 1D, the propeller devices 1,2 are not given a command of steering, i.e., the ship S is not being turned and is proceeding straight in a forward direction. The "stick-out" angle can be defined as the angle between the longitudinal center line L of the ship and the direction of the thrust force produced by the propeller devices 1,2 when considering 0 to be when the propeller devices 1,2, are directed to force water rearward driving the ship forward and 180 to be when the propeller devices are directed to force water forward driving the ship rearward. The propeller devices "stick-out" when the sticking-out angle is other than 0 and 180.
In Fig. 1A, the stick~ut angle of the propeller devices 1,2 is 0, i.e., the thrust force produced by the propeller devices 1,2 is parallel to the direction of travel of the ship S. In Fig. 1 B, the propeller devices 1,2 are turned to a stick-out angle a of about 45 in which case, at a speed of rotation of the propellers 1,2 equal to that in Fig. 1A, in the illustration 217188~
shown in Fig. 1 B, the speed of the ship is lower than in Fig. 1A. In Fig. 1 C, the propeller devices 1,2 are turned fully against each other, in which case the value of the stick-out angle a of each propeller device is about 90. Finally, in Fig. 1 D, the propeller devices 1,2 are turned to a stick-out angle a of about 120 in relation to the longitudinal axis L of the ship in which case, the thrust force of the propeller devices 1,2 moves the ship S
rearward. When the propeller devices 1,2 are turned to a sticking-out position, the control signal of the automatic control system rotates the propeller devices 1,2 in the normal manner, either symmetrically or asymmetrically, and produces the desired steering movement in combination with the reduction of travel speed produced by the sticking out of the propeller devices 1,2. The reduction is speed is exemplified through the various differentstickingoutanglesinFigs. 1A, 1B, 1Cand1D.
Thus, the operation of the automatic control system goes on unchanged while the stick-out angle a of the propeller devices 1,2 exclusively affects the travel speed of the ship S, i.e., the control system is decoupled from the speed regulation control system.
When the stick-out angle a of both propeller devices 1,2 is the same, the automatic control system steers the ship S as if there were no sticking-out function of the propeller devices at all, i.e., any angular variation in the propeller devices desired by the control system is effective in combination with the angle of the propeller devices set or determined by the speed regulation control system. Thus, by means of the sticking-out function, the automatic control system is "fooled" by turning the propeller devices 1,2 the same magnitude in opposite directions. The automatic control system continues the normal running operation, and the operator can adjust the stick-out angle a to the desired value, thereby regulating the travel speed of the ship S continuously.
By means of regulation of the stick-out angte a in accordance with the present invention, it is also possible to maintain the desired travel speed of the ship S and to keep this speed substantially invariable. This can be accomplished so that, after the desired speed is selected for the ship, this speed is maintained by adjusting the stick-out angle while the other conditions, such as currents, wind, etc., are changed. Moreover, setting of the propeller powers is fully free when the propeller devices are sticking out. If necessary, the propeller power can be increased if this is required by the steering. In particular at low travel speeds, if the steering cannot be controlled otherwise by means of the automatic control system, different powers can be employed in the propeller devices if necessary. The propeller powers can be regulated jointly or separately.
Low values of stick-out angle a have almost no effect on the travel speed of a ship.
Also, small stick-out angles a are, yet, desirable, for example, during travel in ice. When the propeller devices have been turned to a slight positive stick-out angle a, they are not blocked by ice equally readily as at large stick-out angles because the propeller devices take the flows from near the hull of the ship S, where there is less ice. This advantage is noticed especially when the propeller devices are provided with nozzles.
As stated earlier, when the stick-out function in accordance with the invention is employed, the automatic control system can steer the ship normally so that, when the stick-out function is combined with automatic control, a steering movement combined with a reduction in speed is obtained. In principle, there are two different modes of steering.
First, there is a so-called symmetric mode of steering, which is illustrated by Fig. 2A in the 217188~
drawing. In symmetric steering, both of the propeller devices 1,2 are turned over the same angle unit ~ in the desired direction. In the case of Fig. 2A, the ship S is steered to the left while both propeller devices 1,2 are turned. In the case of Fig. 2A, the steering angle ~
is about 20. However, as shown in Fig. 2A, the propeller devices 1,2 have not been directed in the same direction, in spite of the symmetric mode of steering, because the propeller devices 1,2 were turned to stick-out to certain angles, as determined by the control system for the speed regulation of the ship. The stick-out angle a of each propeller device 1,2 is about 45. Thus, in the case of Fig. 2A, the first propeller device 1 has been turned to an angle of about 65 (~ + ~) in relation to the longitudinal axis L of the ship S, whereas the second propeller device 2 has been turned to an angle of about 25 (a - ,B) in relation to the longitudinal axis L. In this connection, it is noted that the angle of operation of the propeller devices 1,2 is actually a function of two different angles, one being the stick-out angle which is related to the desired speed of the ship and the other being the control angle determined by the control unit for steering purposes.
In the asymmetric mode of steering, which is illustrated by Figs. 2B and 2C, primarily one propeller device is turned first, and when the steering request is intensified, the other propeller device can be engaged in the steering. Thus, in this respect, the mode of steering is similar to that desuibed in the assignee's Fl Patent No. 92378 of earlier date.
Asymmetric steering can be carried out in two ways, i.e., as a mode of steering that reduces the speed or as a mode of steering that increases the speed. Fig. 2B illustrates a mode of steering that lowers the speed. In the case of Fig. 2B, when the automatic steering system is engaged, the propeller device at the side of the inside curve, i.e., the ` 217188~
first propeller device 1 (in the figure the left propeller device because the ship S is turning left), is turned against the travel direction of the ship S and slows down the speed of the ship and produces turning of the ship. The second propeller device 2 is not turned, at least not as yet with small steering angles. In the case of Fig. 2B, the value of the steering angle ~ is about 20. Since the sticking-out function has been switched on in the embodiment of Fig. 2B, both of the propeller devices 1,2 have been turned. The first propeller device 1 has turned by the sum of the steering angle and the stick-out angle, and the second propeller device 2 has turned by the stick-out angle a. In Fig. 2B, the value of the stick-out angle a is about 45. When the steering angle ~ becomes sufficiently large (for example, 30 or larger), both of the propeller devices 1,2 are turned so that they steer the ship. In such a case, a symmetric mode of steering similar to Fig. 2A is provided.
Asymmetric steering can also be used so that it increases the speed and this mode of steering is illustrated in Fig. 2C. In asymmetric steering that increases the travel speed, the automatic control system first turns the propeller device placed at the side of the outside curve, i.e., in the case of Fig. 2C, the second propeller device 2, which turns in relation to the travel direction of the ship S and increases the speed of the ship and produces turning. When steering takes place with small steering angles, the first propeller device 1, i.e. the propeller device at the side of the inside curve, does not turn. In the case of Fig. 2C, the value of the steering angle ,B is about 20. As shown in Fig. 2C, both of the propeller devices 1,2 have been turned in relation to the middle position, because the propeller devices 1,2 are in the sticking-out function. In the case of Fig. 2C, the value of the stick-out angle a is about 45. Thus, in the illustration in Fig. 2C, the first propeller ~171885 device 1 has been turned in relation to the longitudinal axis L by the stick-out angle a, i.e., about 45, and the second propeller device 2 has been turned by the difference between the stick-out angle a and the steering angle ~, i.e., about 25.
In Fig. 3, an embodiment of the invention is illustrated in which so-called negative sticking-out is employed. In such a case, the propeller devices 1,2 of the ship S are turned inward so that the same steering properties are retained. In Fig. 3, the value of the stick-out angle is about 45, i.e., the propeller currents are directed toward each other. No steering command has been given, so that the course of the ship S is straight ahead. The type of the propeller devices 1,2, however, imposes certain limitations on such negative sticking out, because it depends on the type of the propeller devices and to what extent the propeller currents can be controlled against each other without damage to the equipment.
In Fig. 4, attempts have just been made to illustrate the fact that the sticking-out function in accordance with the invention can also be applied with other propeller devices besides those fitted in the stern of the ship S. Thus, in the embodiment of Fig. 4, it is illustrated that the propeller devices 1',2' may also be placed at the fore of the ship. With such propeller devices placed at the fore, it is also possible to use both positive and negative sticking out. In the situation shown in Fig. 4, no steering command has been given, and the stick-out angle of the propeller devices is about 45.
In accordance with the invention, the value of the stick-out angle a of the propeller devices may vary within a very wide range. The value of the stick-out angle a is not confined to 90 but it may be considerably larger. In principle, the stick-out angle a can 2171~85 be increased up to 180. However, in practice, a limit value of the stick-out angle a may already be encountered at about 135. A corresponding range of stick-out angle can be applied both to positive and to negative sticking out.
Finally, in Fig. 5, the principle of the control system in accordance with the present invention is illustrated as a fully schematic block diagram. As a whole and in general, in Fig. 5, the control system is denoted by reference numeral 10. For the propeller devices, the corresponding reference numerals 1 and 2 have been used as were used in connection with the figures discussed above. As shown in Fig. 5, each of the propeller devices 1,2 is provided with a respective dedicated control device 13,14. The control devices of each of the propeller devices 1,2 are connected to the central unit 11 of the automatic control, i.e., to the autopilot. In addition to the above, the automatic control system in accordance with the invention is provided with a stick-out angle control unit 12 which can be connected with the control system when needed so as to regulate the stick-out angles of the propeller devices 1,2 in the desired way, and thus the speed of the ship.
Of course, it is obvious that the propeller devices 1,2 are additionally provided with a possibility for manual control even if this possibility is not expressly illustrated in Fig. 5.
In practice, the sticking out of the propeller devices 1,2 is carried into effect so that the control device 13,14 of each propeller device is given a common stick-out guide value by means of the separate stick-out angle control unit 12 which determines the speed of the ship. When the central unit 11 of the automatic control has been switched on to control the propeller devices 1,2, it controls the propeller devices in accordance with the preset course irrespective of whether the stick-out angle control unit 12 has been switched on or 2171~85 not. The effecting of the sticking out is, however, not confined to the diagram shown in Fig. 5 alone, but it can also be carried into effect in a number of different ways. However, from the point of view of the present invention, it is essential that, as a result, regulation of the travel speed of the ship is achieved by means of the propeller devices by sticking out while the automatic control has been switched on. Instead of a separate stick-out angle control unit 12, the regulation of the stick-out angle might also be carried out as an internal operation in the central unit 11 of the automatic control so that, in view of the objectives of the invention, the result is the same as in the embodiment as illustrated in Fig. 5.
The examples provided above are not meant to be exclusive. Many other variations of the present invention would be obvious to those skilled in the art, and are contemplated to be within the scope of the appended claims.
SHIP WITH TURNABLE PROPELLER DEVICES
FIELD OF THE INVENTION
The present invention relates to an automatic control system for a ship provided with turnable propeller devices for automatic maintenance of the course of the ship and for controlling the course of the ship in accordance with, or in conformity with, a preset course. The ship is provided with one or more pairs of propeller devices whereby the propeller devices that constitute each pair are arranged symmetrically in relation to the longitudinal center line of the ship and are connected to a central unit of the automatic control system. The central unit can be connected optionally to control the propeller devices that form a pair either in a symmetrical mode of operation or an asymmetrical mode of operation.
BACKGROUND OF THE INVENTION
Automatic control is used in ships for automatic maintenance of the course and for automatic control of the course of the ship in compliance with a preset course. Automatic control is used both in ships provided with rotatable propeller devices and in so-called conventional ships which are steered by means of a rudder. The conduct of ships provided with rotatable propeller devices, however, differs considerably from that of ships provided with a rudder. For this reason, the principles of control of the automatic control in these ships also significantly differ from one another. In this connection, a rotatable propeller device is understood as meaning, for example, such propeller devices rotatable ~_ ~171885 around a vertical shaft through 360 as described in the prior art, for example, in published patents and patent applications such as Finnish Patent Application No. 830373, which corresponds to U.S. Patent No. 4,573,929, Finnish Patent Application No. 853173, which corresponds to Great Britain Patent No. 2,179,312, Finnish Patent No. 79,991, which corresponds to Canadian Patent No. 1,283,004, and Finnish Patent No. 82,007, which corresponds to Canadian Patent No. 1,314,440.
The properties of the rotatable propeller devices include the generation of the force needed for both pushing and steering the ship. In normal ship applications, the ship has two rotatable propeller devices which are used in route navigation for steering the ship.
Of course, there are also other applications, in which the number of the propeller devices is different than two, most likely greater than two, but generally automatic control is used for the control of one or two propeller devices.
In a ship, the propeller devices each have control systems of their own, which systems control both the thrust and the turning angle of the respective propeller device under manual control. The automatic control, i.e., the "autopilot", gives the propeller device control system a request concerning a change in the course, which request is converted by the control system to a turning angle of the propeller device, and possibly an adjust in the thrust. In the conventional prior art control systems, the operator switches on the automatic control so that he manually selects the automatic control to control either the left propeller device or the right propeller device or both of them at the same time.
One of the major problem encountered in these prior art systems occurs in the situations of operation in which the automatic control is switched to control either one, the left or the right one, of the propeller devices. When the propeller device that is subjected to automatic control is placed at the side of the outside curve during a change in the course, the running of the curve itself is usually successful. The problem arises when the automatic control attempts to adapt the course of the ship after the curve to the instruction given, i.e., when the course is aligned after the curve. Then, the setting is not always successful, but the operator has had to bring the ship to the correct course by choosing the automatic control either for the propeller device at the inside curve or for both of the propeller devices. Even this has not been enough in all situations, but sometimes, in aligning the ship after the curve, it has been necessary to use manual control.
In order to solve the control problem described above and avoid manual control, the assignee's earlier Finnish Patent No. 92,378, which corresponds the Great Britain Patent No. 2,259,490, describes a novel automatic course control for a ship provided with rotatable propeller devices, in which ship the propeller devices are arranged as a symmetric pair of propeller devices, i.e., symmetrically arranged with respect to a longitudinal center line of the ship, and connected to the central unit of the automatic control, which unit can be connected optionally to control either one or both of the propeller devices that constitute a pair. According to this prior art system, when both propeller devices are connected to the automatic course control, the automatic control shifts the control devices of the propeller devices to an asymmetric state of operation, in which case, when the automatic control gives a command to make a curve, the automatic control always selects the propeller device at the side of the inside curve for the propeller ~17188~
device that turns the ship. In this case, the force that turns the ship remains sufficient. By means of this arrangement, compared with the prior art systems, remarkable improvements and advantages are obtained, the most important advantage being the fact that the force that turns the ship is also maintained in difficult situations of aligning the ship after a curve.
Further, by means of this arrangement, compared with conventional control systems, a more agreeable conduct of the ship was achieved, because the operation of the control was "smooth" .
However, in certain particular situations, also in the system described in Fl Patent No. 92,378, a certain problem occurred. This problem is manifested in particular in slow running speed and at very low travel speeds. Such very low travel speeds must be used, e.g., during various rescue operations, when collecting oil, when keeping the ship immobile, etc. Very low running speeds are, of course, achieved by reducing the speed of rotation of the propellers, but in such a case, the steering capacity of the ship is also lowered because the thrust curve of the propeller is lowered in proportion to the second power. Further, in the ships it is not possible to lower the speed of rotation of the propeller below the minimum speed of rotation of the propeller. For example, collecting oil requires a speed of about 1.5 knots, and in order that this speed could be reached by lowering the speed of rotation of the propeller alone, in quite a number of cases it would be necessary to go to a speed of rotation of the main engine below its minimum speed of rotation. Thus, at these low travel speeds, it has not been possible to use the automatic control system, but it has been necessary to control the ship manually. Manual control at low speeds is, however, very laborious and moreover, quite inaccurate. For this reason, it would be desirable to be able to use the automatic control of the ship also at such low running speeds.
OBJECTS AND SUMMARY OF THE INVENTION
It is an object of the present invention to provide an automatic control system for a ship having propeller devices which efficiently operates at low travel speeds of the ship.
It is another object of the invention to provide a new and improved automatic control system for a ship including propeller devices in which the specific problem related to the automatic steering of a pair of propeller devices after a curve has been eliminated.
It is yet another object of the invention to provide a new and improved automatic control system for a ship including propeller devices in which the conduct of the ship is smooth during course maneuvers, most particularly during and after curves.
In view of achieving the objects of the invention described above and others, the present invention is mainly characterized in that the automatic control system is provided with a control unit by whose means, irrespective of the situation of operation of the central unit of the automatic control system, the propeller devices that form a pair can be connected to stick out by turning the propeller devices in opposite directions in relation to the longitudinal center line of the ship so as to regulate the speed of the ship. Thus, at a fixed rotational speed of the propellers, it is possible to both varying the speed of the ship as well as to engage in steering maneuvers. In this case, the rotational speed of the propellers can be maintained at a level at least as high as the minimum output speed of the engines while the speed of the ship can be very low to enable the ship to engage in, 217188~
e.g., rescue operations, oil collecting operations, and other operations which require very low speeds and still provide the ship with steering capabilities.
Compared with the prior art control systems, by means of the present invention a number of remarkable advantages are obtained, of which the following are described herein. The most important and the most significant advantage of the invention is expressly the fact that automatic control can be used at low travel speeds. In the manner suggested in the invention, efficient steering is also obtained at low speeds, because the speed of rotation of the propellers does not have to be lowered to a very low level, in which case the thrust of the propeller remains good and, as a result thereof, the steering capacity of the ship's control system is also good. If necessary, the propeller powers can be even increased in order to intensify the steering. When operating in ice, the propeller devices can be used for clearing a furrow in the ice by turning the propeller devices to a positive sticking-out angle and by directing strong propeller currents to the sides of the ship.
It is a further remarkable advantage of the invention that the invention can be carried into effect in existing control systems in a very simple way with a little modification.
The present invention thus comprises first steering control means coupled to at least one pair of propeller devices for individually determining a first angle of operation for each of the propeller devices to control the course of the ship and second speed regulation control means coupled to the propeller devices for determining a second thrust angle for both of the propeller devices independent of the determined first angle of operation of each of the propeller devices. The second thrust angle of each of the propeller devices is an angle defined between the longitudinal center line of the ship and a direction of thrust of a respective one of the propeller devices. The propeller devices are turnable in opposite directions so as to regulate the speed of the ship. Further, the system includes means for turning each of the propeller devices to a third angle which constitutes a combination of the second angle and a respective one of the first angles.
In certain embodiments, the first control means are separate from the second control means while in other the hrst control means comprises an automatic control central unit and the second control means are integrated in connection with the central unit such that turning of each of the propeller devices to the third angle is carried out as an internal operation in the central unit. The turning means are structured and arranged to turn the propeller devices to a positive second thrust angle in which the direction of thrust of the propeller devices are turned away from each other or to a negative second thrust angle in which the direction of thrust of the propeller devices are turned toward each other. The second control means can continuously determine the second angle of the propeller devices as a function of the desired speed of the ship such that the third angle is continuously adjusted accordingly.
In other embodiments, the second control means determine a value of the second angle of the propeller devices within a range from about 0 to about 180 in relation to the longitudinal center line of the ship. The second control means may also continuously determine the second angle of the propeller devices as a function of the desired speed of the ship, whereby the rotational speed of the propeller is constant, and the propeller devices are turned by the turning means to the third angles accordingly to maintain the desired speed of the ship and/or to keep the speed of the ship substantially constant.
21~1885 Further advantages and characteristic features of the invention will come out from the following detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The following drawings are illustrative of embodiments of the invention and are not meant to limit the scope of the invention as encompassed by the claims.
Figures 1A, 1B, 1C and 1D are schematic illustrations of the formation of the sticking-out angle of the propeller devices while the ships runs straight in a forward direction.
Figures 2A, 2B and 2C illustrate various modes of steering in accordance with the invention in situations of "sticking-out" of the propeller devices.
Figure 3 is a schematic illustration of an embodiment of the invention in which a negative sticking-out angle is used in the control of the propeller devices.
Figure 4 is a schematic illustration of an embodiment of the invention in which the propeller devices are placed at the fore of the ship.
Figure 5 is a fully schematic illustration of a ship control system in accordance with the invention in the form of a block diagram.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the accompanying drawings wherein the same reference numerals refer to the same or similar elements, as stated above, the present invention incorporates details of the assignee's Fl Patent No. 92,378 of earlier date, which relates to automatic 2171~8~
_ course control in a ship provided with rotatable propeller devices. However, by means of the present invention, the speed of the ship can be regulated by means of an automatic control device in combination with the course control in accordance with Fl 92,378. In the present invention, the possibility of regulating the speed of the ship is accomplished so that, in the ship, the propeller devices that constitute a pair are turned towards each other, i.e., so as to stick out, in order to reduce the speed of the ship. This is illustrated by way of example in Figs. 1A, 1 B, 1 C and 1 D, wherein the ship is denoted by reference S, the longitudinal center line of the ship is denoted by reference L, the propeller devices are denoted by reference numerals 1 and 2, and the "stick-out" angle or thrust angle of the propeller devices in relation to the longitudinal axis of the ship is denoted by the reference a. In Figs. 1A, 1B, 1C and 1D, the propeller devices 1,2 are not given a command of steering, i.e., the ship S is not being turned and is proceeding straight in a forward direction. The "stick-out" angle can be defined as the angle between the longitudinal center line L of the ship and the direction of the thrust force produced by the propeller devices 1,2 when considering 0 to be when the propeller devices 1,2, are directed to force water rearward driving the ship forward and 180 to be when the propeller devices are directed to force water forward driving the ship rearward. The propeller devices "stick-out" when the sticking-out angle is other than 0 and 180.
In Fig. 1A, the stick~ut angle of the propeller devices 1,2 is 0, i.e., the thrust force produced by the propeller devices 1,2 is parallel to the direction of travel of the ship S. In Fig. 1 B, the propeller devices 1,2 are turned to a stick-out angle a of about 45 in which case, at a speed of rotation of the propellers 1,2 equal to that in Fig. 1A, in the illustration 217188~
shown in Fig. 1 B, the speed of the ship is lower than in Fig. 1A. In Fig. 1 C, the propeller devices 1,2 are turned fully against each other, in which case the value of the stick-out angle a of each propeller device is about 90. Finally, in Fig. 1 D, the propeller devices 1,2 are turned to a stick-out angle a of about 120 in relation to the longitudinal axis L of the ship in which case, the thrust force of the propeller devices 1,2 moves the ship S
rearward. When the propeller devices 1,2 are turned to a sticking-out position, the control signal of the automatic control system rotates the propeller devices 1,2 in the normal manner, either symmetrically or asymmetrically, and produces the desired steering movement in combination with the reduction of travel speed produced by the sticking out of the propeller devices 1,2. The reduction is speed is exemplified through the various differentstickingoutanglesinFigs. 1A, 1B, 1Cand1D.
Thus, the operation of the automatic control system goes on unchanged while the stick-out angle a of the propeller devices 1,2 exclusively affects the travel speed of the ship S, i.e., the control system is decoupled from the speed regulation control system.
When the stick-out angle a of both propeller devices 1,2 is the same, the automatic control system steers the ship S as if there were no sticking-out function of the propeller devices at all, i.e., any angular variation in the propeller devices desired by the control system is effective in combination with the angle of the propeller devices set or determined by the speed regulation control system. Thus, by means of the sticking-out function, the automatic control system is "fooled" by turning the propeller devices 1,2 the same magnitude in opposite directions. The automatic control system continues the normal running operation, and the operator can adjust the stick-out angle a to the desired value, thereby regulating the travel speed of the ship S continuously.
By means of regulation of the stick-out angte a in accordance with the present invention, it is also possible to maintain the desired travel speed of the ship S and to keep this speed substantially invariable. This can be accomplished so that, after the desired speed is selected for the ship, this speed is maintained by adjusting the stick-out angle while the other conditions, such as currents, wind, etc., are changed. Moreover, setting of the propeller powers is fully free when the propeller devices are sticking out. If necessary, the propeller power can be increased if this is required by the steering. In particular at low travel speeds, if the steering cannot be controlled otherwise by means of the automatic control system, different powers can be employed in the propeller devices if necessary. The propeller powers can be regulated jointly or separately.
Low values of stick-out angle a have almost no effect on the travel speed of a ship.
Also, small stick-out angles a are, yet, desirable, for example, during travel in ice. When the propeller devices have been turned to a slight positive stick-out angle a, they are not blocked by ice equally readily as at large stick-out angles because the propeller devices take the flows from near the hull of the ship S, where there is less ice. This advantage is noticed especially when the propeller devices are provided with nozzles.
As stated earlier, when the stick-out function in accordance with the invention is employed, the automatic control system can steer the ship normally so that, when the stick-out function is combined with automatic control, a steering movement combined with a reduction in speed is obtained. In principle, there are two different modes of steering.
First, there is a so-called symmetric mode of steering, which is illustrated by Fig. 2A in the 217188~
drawing. In symmetric steering, both of the propeller devices 1,2 are turned over the same angle unit ~ in the desired direction. In the case of Fig. 2A, the ship S is steered to the left while both propeller devices 1,2 are turned. In the case of Fig. 2A, the steering angle ~
is about 20. However, as shown in Fig. 2A, the propeller devices 1,2 have not been directed in the same direction, in spite of the symmetric mode of steering, because the propeller devices 1,2 were turned to stick-out to certain angles, as determined by the control system for the speed regulation of the ship. The stick-out angle a of each propeller device 1,2 is about 45. Thus, in the case of Fig. 2A, the first propeller device 1 has been turned to an angle of about 65 (~ + ~) in relation to the longitudinal axis L of the ship S, whereas the second propeller device 2 has been turned to an angle of about 25 (a - ,B) in relation to the longitudinal axis L. In this connection, it is noted that the angle of operation of the propeller devices 1,2 is actually a function of two different angles, one being the stick-out angle which is related to the desired speed of the ship and the other being the control angle determined by the control unit for steering purposes.
In the asymmetric mode of steering, which is illustrated by Figs. 2B and 2C, primarily one propeller device is turned first, and when the steering request is intensified, the other propeller device can be engaged in the steering. Thus, in this respect, the mode of steering is similar to that desuibed in the assignee's Fl Patent No. 92378 of earlier date.
Asymmetric steering can be carried out in two ways, i.e., as a mode of steering that reduces the speed or as a mode of steering that increases the speed. Fig. 2B illustrates a mode of steering that lowers the speed. In the case of Fig. 2B, when the automatic steering system is engaged, the propeller device at the side of the inside curve, i.e., the ` 217188~
first propeller device 1 (in the figure the left propeller device because the ship S is turning left), is turned against the travel direction of the ship S and slows down the speed of the ship and produces turning of the ship. The second propeller device 2 is not turned, at least not as yet with small steering angles. In the case of Fig. 2B, the value of the steering angle ~ is about 20. Since the sticking-out function has been switched on in the embodiment of Fig. 2B, both of the propeller devices 1,2 have been turned. The first propeller device 1 has turned by the sum of the steering angle and the stick-out angle, and the second propeller device 2 has turned by the stick-out angle a. In Fig. 2B, the value of the stick-out angle a is about 45. When the steering angle ~ becomes sufficiently large (for example, 30 or larger), both of the propeller devices 1,2 are turned so that they steer the ship. In such a case, a symmetric mode of steering similar to Fig. 2A is provided.
Asymmetric steering can also be used so that it increases the speed and this mode of steering is illustrated in Fig. 2C. In asymmetric steering that increases the travel speed, the automatic control system first turns the propeller device placed at the side of the outside curve, i.e., in the case of Fig. 2C, the second propeller device 2, which turns in relation to the travel direction of the ship S and increases the speed of the ship and produces turning. When steering takes place with small steering angles, the first propeller device 1, i.e. the propeller device at the side of the inside curve, does not turn. In the case of Fig. 2C, the value of the steering angle ,B is about 20. As shown in Fig. 2C, both of the propeller devices 1,2 have been turned in relation to the middle position, because the propeller devices 1,2 are in the sticking-out function. In the case of Fig. 2C, the value of the stick-out angle a is about 45. Thus, in the illustration in Fig. 2C, the first propeller ~171885 device 1 has been turned in relation to the longitudinal axis L by the stick-out angle a, i.e., about 45, and the second propeller device 2 has been turned by the difference between the stick-out angle a and the steering angle ~, i.e., about 25.
In Fig. 3, an embodiment of the invention is illustrated in which so-called negative sticking-out is employed. In such a case, the propeller devices 1,2 of the ship S are turned inward so that the same steering properties are retained. In Fig. 3, the value of the stick-out angle is about 45, i.e., the propeller currents are directed toward each other. No steering command has been given, so that the course of the ship S is straight ahead. The type of the propeller devices 1,2, however, imposes certain limitations on such negative sticking out, because it depends on the type of the propeller devices and to what extent the propeller currents can be controlled against each other without damage to the equipment.
In Fig. 4, attempts have just been made to illustrate the fact that the sticking-out function in accordance with the invention can also be applied with other propeller devices besides those fitted in the stern of the ship S. Thus, in the embodiment of Fig. 4, it is illustrated that the propeller devices 1',2' may also be placed at the fore of the ship. With such propeller devices placed at the fore, it is also possible to use both positive and negative sticking out. In the situation shown in Fig. 4, no steering command has been given, and the stick-out angle of the propeller devices is about 45.
In accordance with the invention, the value of the stick-out angle a of the propeller devices may vary within a very wide range. The value of the stick-out angle a is not confined to 90 but it may be considerably larger. In principle, the stick-out angle a can 2171~85 be increased up to 180. However, in practice, a limit value of the stick-out angle a may already be encountered at about 135. A corresponding range of stick-out angle can be applied both to positive and to negative sticking out.
Finally, in Fig. 5, the principle of the control system in accordance with the present invention is illustrated as a fully schematic block diagram. As a whole and in general, in Fig. 5, the control system is denoted by reference numeral 10. For the propeller devices, the corresponding reference numerals 1 and 2 have been used as were used in connection with the figures discussed above. As shown in Fig. 5, each of the propeller devices 1,2 is provided with a respective dedicated control device 13,14. The control devices of each of the propeller devices 1,2 are connected to the central unit 11 of the automatic control, i.e., to the autopilot. In addition to the above, the automatic control system in accordance with the invention is provided with a stick-out angle control unit 12 which can be connected with the control system when needed so as to regulate the stick-out angles of the propeller devices 1,2 in the desired way, and thus the speed of the ship.
Of course, it is obvious that the propeller devices 1,2 are additionally provided with a possibility for manual control even if this possibility is not expressly illustrated in Fig. 5.
In practice, the sticking out of the propeller devices 1,2 is carried into effect so that the control device 13,14 of each propeller device is given a common stick-out guide value by means of the separate stick-out angle control unit 12 which determines the speed of the ship. When the central unit 11 of the automatic control has been switched on to control the propeller devices 1,2, it controls the propeller devices in accordance with the preset course irrespective of whether the stick-out angle control unit 12 has been switched on or 2171~85 not. The effecting of the sticking out is, however, not confined to the diagram shown in Fig. 5 alone, but it can also be carried into effect in a number of different ways. However, from the point of view of the present invention, it is essential that, as a result, regulation of the travel speed of the ship is achieved by means of the propeller devices by sticking out while the automatic control has been switched on. Instead of a separate stick-out angle control unit 12, the regulation of the stick-out angle might also be carried out as an internal operation in the central unit 11 of the automatic control so that, in view of the objectives of the invention, the result is the same as in the embodiment as illustrated in Fig. 5.
The examples provided above are not meant to be exclusive. Many other variations of the present invention would be obvious to those skilled in the art, and are contemplated to be within the scope of the appended claims.
Claims (10)
1. An automatic control system for a ship with at least one pair of turnable propeller devices for automatic maintenance of a course of the ship and for control of the course in accordance with a preset course, said at least one pair of propeller devices being arranged symmetrically in relation to a longitudinal center line of the ship, comprising first steering control means coupled to said at least one pair of propeller devices for individually determining a first angle of operation for each of said at least one pair of propeller devices to control the course of the ship, second speed regulation control means coupled to said at least one pair of propeller devices for determining a second thrust angle for both of said pair of propeller devices independent of the determined first angle of operation of each of said at least one pair of propeller devices, said second thrust angle of each of said at least one pair of propeller devices being an angle defined between the longitudinal center line of the ship and a direction of thrust of a respective one of said at least one pair of propeller devices, said at least one pair of propeller devices being turnable in opposite directions so as to regulate the speed of the ship, and means for turning each of said at least one pair of propeller devices to a third angle which constitutes a combination of said second angle and a respective one of said first angles.
2. The automatic control system of claim 1, wherein said first control means are separate from said second control means.
3. The automatic control system of claim 1, wherein said first control means comprises an automatic control central unit, said second control means being integrated in connection with said central unit such that turning of each of said at least one pair of propeller devices to said third angle is carried out as an internal operation in said central unit.
4. The automatic control system of claim 1, wherein said turning means are structured and arranged to turn said at least one pair of propeller devices to a positive second thrust angle in which the direction of thrust of said at least one pair of propeller devices are turned away from each other or to a negative second thrust angle in which the direction of thrust of said at least one pair of propeller devices are turned toward each other.
5. The automatic control system of claim 1, wherein said second control means continuously determine said second angle of said at least one pair of propeller devices as a function of the desired speed of the ship such that said third angle is continuously adjusted accordingly.
6. The automatic control system of claim 1, wherein said second control means determine a value of said second angle of said at least one pair of propeller devices within a range from about 0° to about 180° in relation to the longitudinal center line of the ship.
7. The automatic control system of claim 1, wherein said second control means continuously determine said second angle of said at least one pair of propeller devices as a function of the desired speed of the ship and said at least one pair of propeller devices are turned by said turning means to said third angles accordingly to maintain the desired speed of the ship and/or to keep the speed of the ship substantially constant.
8. The automatic control system of claim 1, wherein said first control means control said at least one pair of propeller devices in a symmetric mode of operation.
9. The automatic control system of claim 1, wherein said first control means control said at least one pair of propeller devices in an asymmetric mode of operation.
10. The automatic control system of claim 1, wherein a speed of rotation of said at least one pair of propeller devices is not changed during the determination of said first and second angles during steering of the ships and the turning of said at least one pair of propeller devices to said third angle by said turning means.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI951261A FI951261L (en) | 1995-03-17 | 1995-03-17 | Automatic steering system on a vessel equipped with tilting propellers |
| FI951261 | 1995-03-17 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2171885A1 true CA2171885A1 (en) | 1996-09-18 |
Family
ID=8543071
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002171885A Abandoned CA2171885A1 (en) | 1995-03-17 | 1996-03-15 | Automatic control system in a ship provided with rotatable propeller devices |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0732261A1 (en) |
| CN (1) | CN1134901A (en) |
| CA (1) | CA2171885A1 (en) |
| FI (1) | FI951261L (en) |
| NO (1) | NO961078L (en) |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NO964979L (en) * | 1996-11-22 | 1998-05-25 | Ship Based Systems As | multipurpose Ship |
| FI115763B (en) * | 2003-01-30 | 2005-07-15 | Aker Finnyards Oy | Steering and propulsion arrangements for a vessel |
| FI20030556A0 (en) * | 2003-04-11 | 2003-04-11 | Abb Oy | Method and equipment for steering the ship |
| US7780490B2 (en) * | 2008-09-16 | 2010-08-24 | AB Volvo Penla | Watercraft with control system for controlling wake and method for controlling wake |
| JP2014076758A (en) * | 2012-10-11 | 2014-05-01 | Suzuki Motor Corp | Method and system for estimating movement center of ship |
| CN103010445B (en) * | 2012-12-24 | 2015-06-24 | 上海海事大学 | Steerage compensation device and method of rudder and propeller integrated rotary twin-screw electric propulsion ship |
| CN103552650A (en) * | 2013-11-06 | 2014-02-05 | 中国水产科学研究院渔业机械仪器研究所 | Dual-body water surface carrier and automatic control system |
| FR3046132B1 (en) * | 2015-12-23 | 2018-12-07 | Thales | METHOD FOR CONTROLLING A PROPELLER OF A MARINE VEHICLE |
| CN105923134B (en) * | 2016-04-18 | 2019-06-07 | 太仓弘杉环保科技有限公司 | A kind of intelligence ship adjustment system and its working method |
| EP3652066B1 (en) * | 2017-07-14 | 2024-02-14 | Volvo Penta Corporation | A marine vessel propulsion unit calibration method |
| FI128947B (en) * | 2018-12-21 | 2021-03-31 | Rolls Royce Marine As | Hull structure for integration with a hull of a ship and a method and a thruster control module for manoeuvring a ship |
| CN110182343A (en) * | 2019-07-15 | 2019-08-30 | 哈工大机器人（岳阳）军民融合研究院 | Unmanned boat |
| CN114379744B (en) * | 2020-10-16 | 2024-06-14 | 川崎重工业株式会社 | Ship control system and ship |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6120000Y2 (en) * | 1978-12-06 | 1986-06-16 | ||
| JPS56146494A (en) * | 1980-03-10 | 1981-11-13 | Ishikawajima Zosen Kakoki Kk | Steering equipment for ship |
| FI92378C (en) * | 1991-09-16 | 1994-11-10 | Aquamaster Rauma Oy | Automatic course pilot on a ship equipped with rotatable propeller devices |
-
1995
- 1995-03-17 FI FI951261A patent/FI951261L/en not_active Application Discontinuation
-
1996
- 1996-03-15 CN CN96103616A patent/CN1134901A/en active Pending
- 1996-03-15 NO NO961078A patent/NO961078L/en unknown
- 1996-03-15 CA CA002171885A patent/CA2171885A1/en not_active Abandoned
- 1996-03-15 EP EP96850052A patent/EP0732261A1/en not_active Withdrawn
Also Published As
| Publication number | Publication date |
|---|---|
| NO961078L (en) | 1996-09-18 |
| NO961078D0 (en) | 1996-03-15 |
| CN1134901A (en) | 1996-11-06 |
| FI951261A0 (en) | 1995-03-17 |
| FI951261L (en) | 1996-09-18 |
| EP0732261A1 (en) | 1996-09-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |