1. Field of the Invention
The present invention relates to a control apparatus of multiple ship propellers that controls plural ship propellers, such as outboard motors and inboard motors.
2. Related Art
There is a steering device of an outboard motor generating steering power using an electrical motor in the related art. For example, Japanese Patent No. 2959044 (Patent Document 1) discloses an electrical steering device that generates steering power to steer an outboard motor main body by detecting a rotation angle and a rotation direction of a steering wheel using a sensor and controlling rotations of an electrical motor according to the detected value using a controller.
Also, for example, JP-A-2007-91115 (Patent Document 2) discloses a technique for a control apparatus in a ship of a multi-outboard motor type equipped with plural outboard motors. This ship includes a handle, a steering angle sensor detecting a steering angle of the handle, plural outboard motors attached to the transom, electrical rudder tilters connected to the respective outboard motors, and a control apparatus controlling outputs from the respective outboard motors. With the technique disclosed herein, the control apparatus controls a thrust and a direction of the outboard motors as a whole by regulating outputs, trim angles, or heights of propellers of the respective outboard motors according to the steering angle and a sailing condition of the ship.
A ship of a multi-outboard motor type equipped with more than one, for example, two outboard motors may have the whine in some cases because of a slight difference between the right and left engine speeds. In order to prevent this inconvenience, for example, JP-A-5-86894 (Patent Document 3) discloses a rotation phase control apparatus of an engine for two outboard motors on the right and left each incorporating an engine. This control apparatus reduces vibrations of the hull by cancelling out vibrations of the engines on the right and left.
Patent Document 1: Japanese Patent No. 2959044 (Claims and FIG. 3)
Patent Document 2: JP-A-2007-91115 (Abstract and FIG. 1)
Patent Document 3: JP-A-5-86894 (paragraphs [0015] to [0022], FIG. 2, and FIG. 3)
The steering device of an outboard motor disclosed in Patent Document 1, however, has a problem that a rudder cannot be moved in the event of a fault of the electrical steering device and a ship operator becomes unable to turn the ship as he intended.
Also, the ship operator cannot turn the ship of a multi-outboard motor type disclosed in Patent Document 2 as he intended when it becomes impossible to turn the rudder in one outboard motor in the event of a fault of the electric rudder tilter while the ship is driven by multiple outboard motors. More specifically, in a case where it becomes impossible to turn the rudder in one outboard motor when the rudder is positioned substantially straight, although the intact rudder in the other outboard motor can be turned outward, the ship operator can turn the ship only in one direction. In a case where it becomes impossible to turn the rudder in one outboard motor when the rudder is positioned inward, it is highly likely that the rudder in the failed outboard motor gets in the way and makes it also impossible to turn the rudder in the other outboard motor although the electrical rudder tilter thereof has no trouble. Further, should a fault occur in all the electrical rudder tilters, there arises a problem that the ship operator cannot change a turning direction of the ship at all. Also, there is still another problem that because a thrust difference between the outboard motors is small when an operation angle is small, the whine occurs due to a slight difference between the right and left engine speeds.
Also, it is described that the rotation phase control apparatus of an engine disclosed in Patent Document 3 prevents the occurrence of the whine by cancelling out vibrations of the engines on the right and left. This technique, however, is different from a technique of preventing the occurrence of the whine itself generated in the outboard motors. Moreover, the electrical rudder tilter is not disclosed in this reference.
The invention is devised to solve the problems discussed above and has an object to provide a control apparatus of multiple ship propellers enabling a ship operator to turn a ship by merely operating a steering device without having to go through complicated operations on an accelerator lever even when the ship operator becomes unable to move a rudder in the event of a fault of an electrical rudder tilter while the ship is driven by multiple ship propellers.
A control apparatus of multiple ship propellers according to an aspect of the invention is a control apparatus of multiple ship propellers that controls operation states of at least two ship propellers attached to a transom and transmitting and receiving operation information of the respective ship propellers mutually via a communication member, and is configured to give a thrust difference between the ship propellers in the event of a fault of an electric rudder tilter used to turn a ship by turning a rudder by controlling thrusts of the respective ship propellers according to a detection value of a steering angle detector that detects a steering angle. When a sailing direction of the ship is controlled by the thrust difference, the control apparatus controls the respective ship propellers by using a steering angle threshold up to which the thrust difference is not given between the ship propellers in a region in which the steering angle is small, and in a case where the steering angle exceeds the steering angle threshold, by using a predetermined value of the thrust difference with which the thrust difference is given between the ship propellers.
When configured as above, it becomes possible to give a thrust difference between the ship propellers (outboard motors) by merely operating the steering device in the event of a fault of the electric rudder tilter. Hence, it is no longer necessary to generate thrusts of the respective ship propellers to turn the ship by operating an accelerator lever when it becomes impossible to move the rudder. The ship operator thus becomes able to turn the ship by merely operating the steering device without having to go through complicated operations on the accelerator lever.
The foregoing and other object, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
Hereinafter, a preferred embodiment of a control apparatus of multiple ship propellers of the invention will be described with reference to the accompanying drawings. It should be appreciated, however, that the invention is not limited to the embodiment below and various changes in design are included in the invention.
The ship handling seat controller 4 and the engine controllers 6a and 6b form the control apparatus of the multiple outboard motors. Although these components are provided separately in the illustration of
A ship incorporating the control apparatus of the multiple outboard motors of the first embodiment is configured as above. An operation of the control apparatus of multiple outboard motors will now be described. An operation of the control apparatus of multiple outboard motors of the first embodiment is divided to two steps: steering determination processing and engine thrust difference control. The steering determination processing is to determine a thrust difference to be given between the outboard motors according to the steering angle. The engine thrust difference control is to control engine speeds of the respective outboard motors according to the determined thrust difference.
Firstly, an operation of turn control in the event of a fault of the electric rudder tilters 7a and 7b will be described in accordance with the flowchart of
Referring to
In a case where a thrust difference is given between the engines (outboard motors 5a and 5b), the ship handling seat controller 4 computes a throttle opening (the position of an accelerator lever that regulates a throttle opening) using a value predetermined for a thrust variation and sends the computation result to the engine controllers 6a and 6b. Alternatively, a thrust difference may be given between the outboard motors 5a and 5b in such a manner that the ship handling seat controller 4 determines a thrust difference and sends a thrust variation to the respective engine controllers 6a and 6b while the engine controllers 6a and 6b feed back the thrusts to the handling seat controller 4. In the former case, because the ship handling seat controller 4 carries out all the computations, a function is merely added to the ship handling seat controller 4, which is a normal ship device. In the latter case, because the engine controllers 6a and 6b perform the feedback control, there is an advantage that the precise control is performed more easily.
Methods of the steering determination processing in Step S202 will now be described.
A first method of the steering determination processing in Step S202 of
An engine thrust difference is determined according to the magnitude of a steering angle variation by an operation on the handle 2 by the ship operator. Referring to
A second method of the steering determination processing in Step S202 of
According to the second method of the steering determination processing, a thrust difference for a steering angle variation in a direction to decrease a thrust difference is made larger than a thrust difference for a steering angle variation in a direction to increase a thrust difference. For the control in the direction to increase a thrust difference, a map a indicated by a solid line in
In Step S401 of
In a case where it is determined in Step S401 that the thrust difference control is being performed, the flow proceeds to Step S403 in which whether the command is a command for an operation in a direction in which a steering angle variation decreases an accumulated thrust difference is determined. When the sign of a steering angle variation and the sign of an accumulated thrust difference are the same, the command is a command for an operation in a direction to increase the accumulated thrust difference. Hence, the flow proceeds to Step S402 and a thrust difference is determined using the map a. For example, when an accumulated thrust difference before the command is positive, the ship 1 is in a state where a thrust of the portside motor is larger than a thrust of the starboard motor. In this state, a steering angle variation takes a positive value when the ship operator turns the handle 2 rightward. In other words, when the sings of an accumulated thrust difference and a steering angle variation are the same, the command is a command for an operation in the direction to increase the accumulated thrust difference.
When the sign of a steering angle variation and the sign of an accumulated thrust difference are opposite, the command is a command for an operation in a direction to decrease the accumulated thrust difference. Hence, the flow proceeds to Step S404. For example, when an accumulated thrust difference before the command is positive, the ship 1 is in a state where a thrust of the portside motor is larger than a thrust of the starboard motor. In this state, a steering angle variation takes a negative value when the ship operator turns the handle 2 leftward. In other words, when the signs of an accumulated thrust difference and a steering angle variation are opposite, the command is a command for an operation in the direction to decrease the accumulated thrust difference.
In Step S404, a thrust difference is determined according to the steering angle variation from the map b shown in
After the thrust difference is determined in Step S404 according to the steering angle variation, whether the positive or negative sign of the accumulated thrust difference is different from the sign of the last value is determined in Step S405. In a case where the signs are different, a value of the thrust difference is determined so that the accumulated thrust difference becomes 0 in Step S406. In order to prevent a thrust difference determined from the map b used for the control to decrease an accumulated thrust difference from being used for the control in the direction to increase an accumulated thrust difference, the thrust difference is clipped at 0 when an accumulated thrust difference changes from negative to positive and vice versa.
A first method of the engine thrust difference control in Step S203 of
Referring to
When the thrust difference is other than 0, whether the thrust difference is positive or negative is confirmed in Step S602. When the thrust difference is positive, a thrust of the portside motor is increased and a thrust of the starboard motor is decreased. Conversely, when the thrust difference is negative, a thrust of the portside motor is decreased and a thrust of the starboard motor is increased. For example, in a case where a thrust of the outermost outboard motor is changed, the control to increase a thrust of the portside motor by half the value of the trust difference and to decrease a thrust of the starboard motor by half the value of the thrust difference is performed so that a total thrust of all the outboard motors does not change. In a case where there are four or more outboard motors and a thrust of the inner outboard motor is changed, the ship can be turned efficiently by making a thrust difference equal to or smaller than a. thrust of the outermost outboard motor. In a case where an odd number of outboard motors are mounted to the ship, the outboard motor in the center may not be taken into account regarding a thrust difference because this outboard motor has little influence when the ship is turned. A thrust is changed by regulating a throttle opening or an amount of fuel.
After thrusts are changed in Step S603 and Step S604, thrust upper and lower limits clip processing is performed in Step S605. This processing prevents overheating caused by exceedingly increasing a thrust or prevents an engine stall caused by exceedingly decreasing a thrust. In a case where a thrust is clipped, the thrust can no longer be changed over the limit. However, by decreasing a thrust of the other outboard motor when the thrust is clipped at the upper limit and by increasing a thrust of the other outboard motor when a thrust is clipped at the lower limit, the thrust difference determined in Step S202 can be given between the outboard motors 5a and 5b. It thus becomes possible to turn the ship smoothly.
A second method of the engine thrust difference control in Step S203 of
Referring to
As has been described above, according to the control apparatus of multiple ship propellers of the first embodiment, a thrust difference can be given between the outboard motors 5a and 5b by an operation on the handle 2 in the event of a fault of the electric rudder tilter 7a and 7b. Hence, it is no longer necessary to generate thrusts of the respective outboard motors 5a and 5b by an operation on the accelerator lever in order to turn the ship when it becomes impossible to move the rudders. Hence, the ship operator becomes able to turn the ship by merely operating the handle 2 without having to go through complicated operations on the acceleration lever.
Also, it becomes possible to prevent the whine by giving a predetermined or larger thrust difference by avoiding an operation region in which a fine thrust difference such that causes the whine is given between the outboard motors.
For the control in the direction to decrease a thrust difference in the presence of thrust difference, a larger thrust difference for the steering angle is given between the outboard motors than by the control in the direction to increase a thrust difference in the absence of thrust difference. Hence, the ship operator becomes able to quickly return the ship to a state where there is no thrust difference. The ship thus becomes easier to handle for the ship operator and sails safely.
Also, the ship is allowed to sail safely by controlling a total thrust of all the outboard motors in the absence of a thrust difference between the outboard motors 5a and 5b and a total thrust of all the outboard motors when a. thrust difference is given between the outboard motors 5a and 5b to take the same value.
Also, ship responsivity can be obtained by configuring in such a manner that in a. case where a thrust difference is given between the outboard motors 5a and 5b in a state where no thrust difference has been given between the outboard motors 5a and 5b, either the outboard motor a or the outboard motor b whose thrust is to be changed is controlled only in a direction to increase the thrust, and in a case where a thrust difference is eliminated after the thrust difference is given between the outboard motors 5a and 5b, a thrust of the outboard motor a or the outboard motor b whose thrust is increased is controlled to decrease the thrust only to the thrust before the thrust difference is given between the outboard motors 5a and 5b or to a thrust of an outboard motor having the smallest thrust among the plural outboard motors.
Various modifications and alterations of this invention will be apparent to those skilled in the art without departing from the scope and spirit of this invention, and it should be understood that this is not limited to the illustrative embodiments set forth herein.
Number | Date | Country | Kind |
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2011-048830 | Mar 2011 | JP | national |