STEERING AND MANOEUVERING SYSTEM FOR WATER-BORNE VESSELS

Abstract: Steering and manoeuvering system for water-borne vessels with two individually turnable propulsion units arranged mutually spaced athwartships in the stern portion of the vessel, and including an actuating turning device (7, 8) actuable by a steering control (1), e.g. a lever, such as to maintain the propulsing units parallel during turning in normal sailing of the vehicle ahead or astern, i.e. in the so-called normal steering mode, and an actuating drive device (9, 10) for setting the propulsive power and direction ahead/astern of the respective propulsion unit, said drive device being actuable by a power control (2). The system is switchable between said normal steering mode (3) and at least one special manoeuvering mode (4, 5), in which the two propulsion units achieve a force resultant directed substantially athwartships for athwartships and/or turning movement of the vessel.

Description: STEERING AND MANOEUVERING SYSTEM FOR WATER-BORN VESSELS The invention relates to a steering and manoeuvering system fo water-born vessels with two individually turnable propulsion units arranged at the stern portion of the vessel and mutually spaced athwartships. These units may be such as jet units, turnable so-called thrusterε or turnable propeller units of th "AQUAMATIC" , "Z-DRIVE" type or the like, (but not propeller units with a stationary propeller shaft and a separate rudder) A first type of known steering and manoeuvering system for vessels with such double propulsion units includes an actuatin turning device, which is actuable by a steering control, e.g. lever or a wheel, and keeps the propulsion units parallel whil being turned, and an actuating drive device, which is actuable by a power control for adjusting the propulsive power ahead or astern of the respective propulsion unit. The vessel can thus steered for sailing ahead or astern in a desired starboard/por direction, as well as for executing a rotating or turning movement (one unit set for propulsion ahead and the other one for propulsion astern) which can be to advantage in manoeuveri in ports, harbours and other cramped situations. It is not possible to achieve pure athwartships movement with such a system, however. Athwartships movement namely requires that bo propulsion units can be turned in opposite angular directions with opposing directions of propulsion. In a second type of known steering and manoeuvering system (US-A-3 976 023) all steering functions are achieved by a sing controlling joystick which is movable in two dimensions. When the joystick is moved forwards/backwards the combined propulsi effect is increased ahead or astern (by different adjustments the turning angle) and when the joystick is moved sideways port/starboard steering action is achieved to port or starboar The power of the propulsion units can be regulated at the same ti e by pulling out or depressing a knob on the joystick. Turning and athwartships movement of the vessel can be achieved for certain positions of the joystick. Such a steering and manoeuvering system can indeed appear to be simple, since only one lever is used, but even so it requires that the steersman of the vessel with this system is given extensive training in order to master different manoeuvres, particularly manoeuvers in harbours and ports. In addition, wit this system it is difficult to compensate for external forces, e.g. those coming from wind and current, which act on the vesse in a translatory and/or rotary direction. The object of the present invention is to achieve a steering an manoeuvering system of the first type mentioned above, which furthermore enables a person to execute complicated special manoeuvers after only having passed a short training course. In normal sailing, it shall thus be possible to steer the vessel t port or starboard conventionally with the aid of a control such as a wheel or lever, while the power control is utilized in a way which is easily understood and natural, from the aspect of logical control, in the execution of special manoeuvers. This object is achieved by the invention in- hat the steering and manoeuvering system includes a function selector with the aid of which the system is switchable between a normal steering mode, where the propulsion units are kept parallel during steering, and at least one special manoeuvering mode, where the steering control is disconnected from its normal steering function and said actuating turning device is instead actuated automatically irrespective of the position of the steering control for setting the two propulsion units at symmetrical turning angles in opposite directions so that the two propulsio units achieve a force resultant directed substantially athwart¬ ships for athwartships and/or turning movement of the vessel, while said actuating drive device is actuated for setting the two propulsion units in opposing propulsive directions ahead/astern . By the automatic setting of the angular positions of the propu sion units in the special manoeuvering mode, the steersman can concentrate on relatively simple control functions, such as increasing or decreasing the turning or athwartships movement rate, with the aid of the power control. It has been found tha such manoeuvering can be carried out extremely simply, but sti exactly and effectively, and since normal sailing takes place conventionally with the aid of the steering and power controls the steersman can quickly learn to master the steering and manoeuvering system in accordance with the invention. The special manoeuvering modes can suitably be an athwartships movement mode and a turning mode, as defined in claim 2. In the respective special manoeuvering mode (turning or athwar ships movement) the steering control is preferably utilized to adjust the turning angle of the propulsion units such that the turning angles are changed symmetrically in opposite direction while retaining symmetry, whereby the point of action of the force resultant is moved along the fore and aft line of the vessel or an extension of this line, cf . claim 3. In the athwartships mode, the steersman can thus readily achieve eith a compensating torque, if the vessel is acted on by outside forces as a result of wind or current, or a superposed turning movement. In the turning mode, such displacement of the force resultant point of action achieves an amplification or weakenin of the torque . Switching between the different modes is preferably achieved with the aid of a manually settable function selector (cf. clai 5), particularly a preselector switch, which does not switch to the set mode until certain operating or manoeuvering condition have been met (cf. claims 6, 7 and 11). As appears from claims 7-11, the power control can consist either of a conventional double lever control or a special control, which achieves synchronous propulsion power setting, when it is moved in a first dimension, and power balancing by changing the propulsive power in the opposite direction (ahead-astern) of the respective propulsion unit, when it is moved in a second dimension. The invention will be described in more detail below with refe rence to the accompanying drawings, which illustrate two exemplary embodiments. Figure 1A schematically illustrates a control unit included in a steering and manoeuvering system according t a first embodiment; Figure IB is a heavily simplified block diagram of the steering and manoeuvering system in its entirety; Figures 2A and 2B illustrate in a corresponding way a control unit and a steering and manoeuvering system in accordance with a second embodiment; Figure 3 schematically illustrates how the steering and manoeuvering system in accordance with the inven¬ tion functions when sailing in two different special manoeuvering modes (turning and athwartships movement); and Figure 4 schematically illustrates how the propulsion powe is distributed in the steering and manoeuvering system according to Figures 2A and 2B . A steering and manoeuvering system built up around two conven¬ tional components is illustrated in Figures 1A and IB, namely steering control 1 in the form of a lever for steering a vesse to starboard or port and a double lever control 2 for controli propulsion power (engine power) and propulsion direction (ahead/astern) of the starboard and port propulsion units. The steering and manoeuvering system can thus be installed by connection to an existing equipment. In addition, a function selector is fitted, this being in the form of a preselection switch with three buttons 3, 4, 5 for selecting a normal steering mode, a turning mode or an athwartships movement mode Position sensing means a, b, c, d (Figure IB) are arranged for sensing ahead or astern positions of each control lever 2a, 2b The steering control 1, the preselection switch 3, 4, 5 and th control lever position sensing means a, b, c, d are connected an electronic steering unit 6 provided with logical circuits, and which on its output side gives control signals to actuatin turning units 7 , 8 for angular control of the starboard and po propulsion units, respectively. These turning units 7 , 8 are preferably servo controlled units of electromechanical, electr hydraulic or electropneu atic type. The power control 2 is conventionally connected to actuating drive units 9, 10, e.g. mechanical or hydraulic transmission for acting on the propul¬ sion power (or engine power) and propulsion direction (ahead/astern) of the respective propulsion unit. The logical circuits of the steering unit 6 decode the incomin signals and actuate both turning units 7, 8 so that the turnin angle of the propulsion units correspond to a desired sailing mode and the setting of the steering and power controls. For the NORMAL steering mode (preselection button 3) the vessel is steered and manoeuvered conventionally, the steering control functioning such that the propulsion units are kept parallel as they are turned, while the propulsion power and direction of th respective propulsion unit can be set individually with the aid of the power control levers 2a, 2b. This steering mod'e is gene¬ rally used for movement ahead, astern or simple manoeuvers. For relatively complicated manoeuvers such as those needed in harbours, tying up to a quay or pier etc. , the preselection buttons 4 and 5 are used for switching onto the turning mode o the athwartships mode, respectively. The parallel relationship of the propulsion units caused by the steering control 1 is disengaged in these special manoeuvering modes, and the steeri unit 6 then sets the propulsion units in symmetrical turning angles in opposite directions. A necessary prerequisite for th effectiveness of these special manoeuvering modes is that the propulsive directions of the propulsion units are mutually opposite, i.e. one power lever, e.g. 2a, is set ASTERN and the other, e.g. 2b, at AHEAD. In the TURNING mode (cf. Figure 3), both propulsion units are directed towards a point astern the vessel on the extension of its fore and aft line. When the steering control 1 is set in neutral position (B and H in the Figure) , these turning angles are predetermined by being programmed into the steering unit 6 and result in that the vessel turns to port (position B) .or to starboard (position H) about its centre of gravity in the lateral plane. In this mode, the steersman can increase or decrease the rate of turn during the course of manoeuvering by using the levers 2a, 2b or adjust the angles of the propulsion units Cwhile maintaining symmetry) and thereby displace the point of action in the fore and aft direction with the aid of the steering control 1, see positions A, C, G and I. In the ATHWARTSHIPS mode both propulsion units re directed towards the centre of gravity of the vessel in the lateral plane, when the steering control 1 is set in the neutral position, see positions E and K. In this case the vessel will moved exclusively ahtwartships to port or starboard, provided that wind and current do not cause any torque. If this should the case, the steersman can apply a compensating torque by a corresponding setting of the steering control 1, the point of action of the force resultant then being displaced fore or af see positions D, F, J and L in Figure 3. If the levers 2a, 2b of the power control 2 are in -the positi "both ahead", "neutral" or "both astern", (which is sensed by the means a, b, c and d, Figure IB), the NORMAL mode is kept engaged, even if one of the buttons 4 or 5 has been depressed. Preselection of the desired special manoeuver mode can thus t place before the intended manoeuver, the mode in question bei engaged automatically when the force directions are shifted wi the aid of the levers 2a, 2b. However, changing between the turning and athwartships modes can take place without delay by depressing the respective button 4 and 5 during the manoeuver progress. Similarly, the NORMAL mode is reengaged as soon as t button 3 is depressed. In the steering system according to Figures 2A and 2B there is used a principally similar steering control 1 and the same preselector switches 3, 4, 5 as in Figure 1A. However, the pow control is formed differently and comprises a first lever 2'a for synchronous setting of the propulsive power (or engine power) ahead/neutral/astern of the propulsion units, and a second lever 2'b for differential balancing of the propulsive powers/directions (starboard/neutral/port) such that, when the lever 2'a is in a neutral position and the lever 2'b is being swung to port, the propulsive power of the port propulsion uni astern is increased and to a corresponding degree that of the starboard propulsion unit is increased ahead, and when swingin the lever 2'b to starboard, the propulsive power of the star¬ board propulsive unit is increased astern and that of the port propulsive unit is increased to a corresponding degree ahead. The lever 2'a is then used to adjust the amount of power while maintaining the vectorial difference between the propulsive powers, ahead or astern, for compensating exterior forces acti in the fore and aft line of the vessel. Co-action between the levers 2'a and 2'b and their vectorial effect on power is illustrated in Figure 4. It has been found that a power control according to- Figure 2A very simple to handle after only a short training course for t person concerned. In the NORMAL mode the vessel is steered by the steering contr 1, and the propulsive power lever 2'a functions as a parallel- connected double lever control, the power balancing lever 2'b achieving increase/decrease of the power of the respective propulsion unit. When the lever 2'b is set in the neutral posi tion, the power on both units is in mutual balance over the entire domain ahead-neutral-astern for the lever 2'a. Conse¬ quently, the NORMAL mode is retained engaged, even when one of the buttons 4, 5 is depressed. The preselected special manoeuvering mode is enabled as soon a the lever 2'b is moved to port or starboard sufficiently far f one propulsion unit to propell ahead and the other astern, see the positions (H) in Figure 4, which corresponds to a double lever control being set with one propulsion unit in the propulsive direction ahead and the other one astern. Both propulsion units are now acted on symmetrically, but with different force directions, when the power is changed by the lever 2'b towards the desired side for athwartships or turning movement . The steering control 1 can also be utilized in this case for fine adjustment of the point of action of the force resultant the TURNING or ATHWARTSHIPS modes, as illustrated in Figure 3. In addition, some propulsive power can be superposed ahead or astern with the aid of the propulsive power lever 2'a for compensating current or wind action in the fore and aft direc¬ tion of the vessel. The steering and manoeuvering system other wise functions in a corresponding manner as in the preceding embodiment . In this case, however, all transmission from the steering control 1, preselector switches 3, 4, 5 and the power control 2 takes place via a central electronic steering unit 6', which controls the two actuating turning units 7', 9' as well as the two actuating drive units 8', 10' for the starboard and port propulsion units. For reasons of safety an emergency system (a so-called back-up system) with simple individual control means and indicators can also be connected for direct control of the actuating turning and drive units 7'-10'. The steering and manoeuvering system can be modified by one skilled in the art in many ways within the scope of the following claims. For example, the levers 2'a and 2'b may be replaced by a single lever of the joystick type, which is . movable in two dimensions. In addition, it may be sufficient with only one special manoeuvering mode, e.g. TURNING, ATHWART¬ SHIPS or a combined TURNING/ATHWARTSHIPS mode. Alternatively, three or more special manoeuvering modes can be used. The steering control 1 can be replaced by a wheel. The conditions for initiating a preselected sailing mode can be varied as desired. Finally, preadjusting means can be arranged, suitably placed near the control unit for individually adjusting the ATHWARTSHIPS and TURNING modes, so that the presetting of the turning angles of the propulsion units give the desired effect in the respective special mode (when the steering control is in a neutral position) .

Claims: C L A I M S 1. Steering and manoeuvering system for water-born vessels with two individually turnable propulsion units arranged at the stern portion of the vessel and mutually spaced athwartships, including - an actuating turning device (7,8) for controlling the turning angles of the two propulsion units such that they remain mutually parallel in normal sailing of the vessel ahead or astern, which is the so-called normal steering mode, said turning device being actuable by a steering control (1), e.g. a steering lever or wheel, and - an actuating drive device (9,10) for setting the propulsive power and direction ahead/astern of the respective propulsion unit, said drive device being actuable by a power control (2) , c h a r a c t e r i z e d i n that the steering and manoeuvering system includes a function selector (3,4,5) with the aid of which the system is switchable between - said normal steering mode (3), and - at least one special manoeuvering mode (4,5), where the steering control (1) is disconnected from its normal steering function where the propulsion units are kept parallel, and said actuating turning device (7,8) is instead actuated automatically irrespective of the position of the steering control (1) for setting the two propulsion units at symmetrical turning angles in opposite directions so that the two propulsion units achieve a force resultant directed substantially athwartships for athwartships and/or turning movement of the vessel, while said actuating drive device (9,10) is actuated for setting the two propulsion units in opposing propulsive directions ahead/astern. 2. Steering and manoeuvering system as claimed in claim 1, c h a r a c t e r i z e d i n that said special manoeuver modes include an athwartships movement mode for moving the vessel paral to itself to starboard or port, both propulsion units bei kept directed towards the centre of gravity of the vessel the lateral plane, possibly towards a point displaced ast or ahead of this point for compensating outside forces attempting to turn the vessel, and a turning mode for clockwise or anti-clockwise turning of the vehicle about said centre of gravity, such that both propulsion units are kept directed towards a point astern situated on the extension of the fore and aft line of the vessel (fig. 3) . 3. Steering and manoeuvering system as claimed in claim 1 or c h a r a c t e r i z e d i n that, in the respective special manoeuvering mode, said steering control (1) actuates the actuating turning device (7,8) such that the turning angle are changed symmetrically in opposing directions, whereby the point of action of the force resultant is displaced along the vessel's fore and aft line or the extension thereof. 4. Steering system as claimed in claims 2 and 3, c h a r a c t e r i z e d in that, in said athwartships movement mode, movement of t steering control (1) to starboard achieves displacement of said point of action astern (E-F, Fig. 3), when the vessel is moved athwartships to port, and ahead (K-L) , when the vessel is moved athwartships to starboard, while movement the steering control (1) to port achieves displacement of said point of action ahead (E-D), when the vessel is moved athwartships to port, and astern (K-J), when the vessel is moved athwartships to starboard, and - in that, in said turning mode, a movement of the steering control (1) to starboard achieves displacement of said poi of action astern (B-C) , when the vessel is turned anti-clockwise, and ahead (H-I), when the vessel is turned clockwise, while a movement of the steering control Cl) to port achieves a displacement of said point of action ahead (B-A) , when the vessel is turned anti-clockwise, and aster (H-G) , when the vessel is turned clockwise (Fig. 3). 5. Steering and manoeuvering system as claimed in any one of the preceding claims, c h a r a c t e r i z e d i n that the function selector (3,4,5) is manually settable for selecti said normal steering mode or a special manoeuvering mode. 6. Steering and manoeuvering system as claimed in claim 5, c h a r a c t e r i z e d i n that the function selector i a .preselector switch (3,4,5) which does not achieve switching the set function until certain operational or manoeuvering conditions are complied with. 7. Steering and manoeuvering system as claimed in any one of claims 1-6, wherein said power control is constituted by a conventional combined control (2) with two parallel, movable levers (2a,2b) adjacent each other, each of which is connected to a respective propulsion unit, c h a r a c t e r i z e d i n that position sensing means (a,b,c,d) are arranged for sensing the ahead or astern position of each lever (2a,2b) or its associated actuating device, and in that a necessary condition for switching from said normal steering mode to a special manoeuvering mode is that one lever or said device assumes a position of ahead and the other lever or said device assumes a position of astern. 8. Steering and manoeuvering system as claimed in claim 7, c h a r a c t e r i z e d i n that, in the respective special manoeuvering mode, the mutual relative positions of t power control levers (2a,2b) determine whether turning and/or athwartships movement takes place to starboard or port. 9. Steering and manoeuvering system as claimed in claim 7 or c h a r a c t e r i z e d i n that said steering control (1), said function selector (3,4,5) and said position sensing means (a,b,c,d) are connected to a steering unit (6) which actuates said actuating turning device (7,8), whereas said po control (2) is connected to said actuating drive device (9,10) without the intermediary of said steering unit (6). 10. Steering and manoeuvering system as claimed in any one of claims 1-6, c h a r a c t e r i z e d i n that the power control (2') is settable in two dimensions, namely in a first dimension (2'a) for synchronous setting of the propulsive powe ahead/neutral/astern of both propulsion units and in a second dimension (2'b) for differential power balancing starboard/neutral/port between the two propulsion units. 11. Steering and manoeuvering system as claimed in claim 10, c h a r a c t e r i z e d i n that the power control includes two separate levers (2'a, 2'b), one for each of said dimensions . 12. Steering and manoeuvering system as claimed in claim 10 o 11, c h a r a c t e r i z e d i n that a necessary condition for switching from said normal steering mode to a special manoeuvering mode is that the power control (2') is se such that one propulsion unit is propulsive ahead and the othe astern (positions (H) , Figure 4). 13. Steering and manoeuvering system as claimed in any one of claims 10-12, c h a r a c t e r i z e d i n that said steering control (1), said function selector (3,4,5) and said power control C2') are connected to a steering unit' (6') which controls said actuating turning device (7',8') as well as said actuating drive device (9',10').

Inventors: NILSSON KURT, NILSSON, KURT
Applicants: STYR KONTROLL TEKNIK I AB, STYR-KONTROLL TEKNIK I AB
Application year: 1988
Main classification: B63H25
IPC codes: B63H21, B63H25