JPH088278Y2 - Marine main engine control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a device for controlling the rotational speed of a marine main engine (diesel engine), and more particularly to preventing overspeed of the main engine.

[Conventional technology]

As conventional examples of this marine main engine control device, there are those disclosed in Japanese Patent Application No. 62-137118 and Japanese Patent Application No. 62-179118, which are prior applications of the present applicant. Shown in the figure and described below.

In FIG. 3, OP is an arithmetic unit, PID is a PID controller (hereinafter referred to as controller PID), 1LM is a first limiter, and ACT.
Is an actuator, RA is a fuel pump fuel rack (not shown), ENG is a main engine, TG is a turning gear, and SE is a sensor for detecting the number of revolutions.

The computing unit OP obtains the deviation between the command rotational speed OR from the steering wheel (commander) (not shown) and the actual rotational speed FB from the sensor SE, and transmits this to the controller PID.

The controller PID has P (proportional), I (integral), D
(Differentiation) operation is performed and output as an actuator position command. Note that each constant (proportional gain, integration time, derivative time) in the controller PID is continuous according to at least one of a plurality of elements such as the actual rotation speed FB, horsepower, actuator ACT position, fuel rack RA position, and the like. It is variable within the range. This is to improve the settability of the main engine ENG when the command rotational speed OR is changed or when the load changes.

The first limiter 1LM determines the upper limit of the actuator position command, and the upper limit is variable according to the command rotational speed OR or the like, and the actuator position command up to the upper limit is passed.

Based on this actuator position command, the actuator ACT adjusts the fuel rack RA position, and the rotation speed of the main engine ENG is controlled.

In the above marine main engine control device, the main engine EN
In order to protect G, an overspeed detection rotation speed higher than the rated rotation speed is defined, and a device that normally stops the main engine ENG when the actual rotation speed FB exceeds the detection rotation speed (not shown). Is attached. This overspeed trip is disclosed in Japanese Patent Publication No. 56-7504.

[Problems to be solved by the device]

In general, when navigating outside the sea, in order to reach the destination quickly, the command rotational speed OR is often set to the rated rotational speed or a high rotational speed close to it, and if this is in stormy weather, the propeller will protrude to the sea. No load, actual speed
FB increases rapidly, increasing the chances of overspeeding.

The causes of this overspeed are as follows. In operating conditions other than rough weather, the constants of the controller PID in FIG. 3 are set so that the sensitivity becomes dull so that hunting does not occur with respect to changes in the command rotational speed OR and load fluctuations. If the constants of the controller PID are set to make the sensitivity dull, if the propeller projects above the sea due to a large swell in stormy weather, the control by the controller PID will not catch up and the actual speed will increase rapidly. become. The overspeed is set just above the rated speed, and the commanded speed OR is also set close to the rated speed as described above, so if the propeller protrudes into the sea while the sensitivity of the controller PID is dull, Immediately overspeed is reached and the main engine will stop. Stopping the main engine during stormy weather is dangerous and must be avoided.

Therefore, even if the present invention sails at a high rotation speed close to overspeed and makes it difficult to cause hunting as described above, if it encounters in stormy weather and the propeller is exposed to the sea, it will not cause overspeed. The challenge is to be able to control.

[Means for solving the problem]

The means of the present invention comprises an arithmetic unit for obtaining a deviation between a commanded rotation speed and an actual rotation speed, a PID controller for performing proportional, integral, and differential operations on the deviation to output as an actuator position command, and the PID controller described above. In a marine main engine control device equipped with an actuator that operates based on actuator position command output to control the fuel rack position, a standard set to be higher than the rated speed of the main engine and lower than the overspeed detection speed. A comparator that compares the number of revolutions with the actual number of revolutions, outputs a holding signal when the actual number of revolutions is less than this reference number of revolutions, and outputs a switching signal when the actual number of revolutions exceeds this reference number of revolutions. , Each constant of the PID controller is set to a normal value based on the holding signal, and each constant of the PID controller is switched to a value having a higher sensitivity than a normal value based on the switching signal. A first switch, and the actuator position command output from the PID controller is transmitted to the actuator based on the hold signal, and the actuator position command output from the PID controller based on the switching signal is passed through a limiter. A second switch for transmitting to the actuator is provided, and the limiter configured to pass by the switching signal instead of the holding signal allows only the actuator position command output in the decreasing direction or the current state to pass. It is characterized by that.

[Action]

When the load on the main engine is suddenly lightened due to the propeller protruding from the sea surface in rough weather, the reference speed between the overspeed and the rated speed is immediately reached. Then, the comparator operates so that the first switch switches the PID controller to high sensitivity, and the second switch switches to pass through the limiter. As a result, the actuator position command output from the PID controller sharply decreases in response to high sensitivity,
This command for the reduction direction is transmitted as it is through the limiter, and suppresses the rapid increase in the rotational speed of the main engine with respect to the rapid decrease in the load.

If the increase in the main engine speed due to the reduction of the load is suppressed, the main engine speed decreases, but the high-sensitivity PID controller predicts this tendency and increases the actuator position command output. Also, when the rotation speed is equal to or higher than the reference rotation speed, the first switch and the second switch are kept switched, and the main engine speed is changed via the limiter until the rotation speed of the main engine reaches the reference rotation speed. Only the actuator position command output that maintains the current speed is output.

In this way, when the load on the main engine suddenly becomes lighter, the engine speed is rapidly reduced to prevent overspeed, and the load is adjusted to a normal value by controlling it so that it does not drop significantly below the reference speed. When it returns, the command rotation speed near the rated rotation can be immediately restored.

When the weather is not heavy, the main engine is rotating near the command speed, which is close to the rated speed, and does not exceed the reference speed. Then, the comparator does not work, the PID controller remains at low sensitivity, and the limiter is also bypassed. As a result, the actuator position command output from the PID controller corresponds to low sensitivity, and the rotation speed of the main engine is controlled in a normal state without causing hunting.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The same components as those in the conventional example are designated by the same reference numerals as those in FIG. 3 and their description is omitted.

FIG. 1 shows the first embodiment, which is different from the conventional example of FIG. 3 in that the comparator CO, the first switch 1SW, the normal sensitivity setting device NS, the high sensitivity setting device HS, the second switch 2SW, 2 limiter 2L
That is the addition of M.

The comparator CO compares the actual rotation speed FB with the reference rotation speed LR and
When <LR, a holding signal is output to hold the first switch 1SW and the second switch 2SW in the illustrated state, and when FB ≧ LR, a switching signal is output and both switches 1SW and 2SW are switched. The reference speed LR is set to a value between the rated speed of the main engine ENG and the overspeed detection speed, or a value between the upper limit of the command speed and the overspeed detection speed when sailing in the open sea. To be done. Further, when the rated rotation speed is, for example, 76 rpm, the overspeed detection rotation speed is about 82 rpm.

The second limiter 2LM passes the actuator position command in the decreasing direction or the current position and does not pass the actuator position command in the increasing direction.

In the first embodiment, the actual rotation speed FB is the reference rotation speed LR.
If it is smaller, both switches 1SW and 2SW are held in the state shown in the figure as described above, so that each constant of the controller PID is adjusted within the normal range by the signal from the normal sensitivity setting device NS, The actuator position command from the PID is transmitted to the actuator ACT via the second switch 2SW under the limitation of the first limiter 1LM, and the main engine ENG is controlled as in the conventional manner with emphasis on settling.

When the actual speed FB suddenly increases and exceeds the reference speed LR due to a sudden load decrease such as the propeller protruding to the sea during rough sea navigation, etc.
W, 2SW switches from the state shown in the figure.

Therefore, the normal sensitivity setting device NS is opened, the signal from the high sensitivity setting device HS is transmitted to the controller PID via the first switch 1SW, and each constant thereof is changed to a value having higher sensitivity than usual. For example, the proportional gain (1.7), the integral time (3.0), and the derivative time (0) are changed to the proportional gain (3.0), the integral time (0.5), and the derivative time (0.7).

In addition, by switching the second switch 2SW to the second limiter SLM side, the actuator position command from the controller PID can be transmitted to the first limiter 1LM, the second limiter 2LM, and the second switch.
It is transmitted to the actuator ACT through 2SW in order.

At this time, depending on the changing state of the actual rotation speed FB, the controller PI
There is a possibility that D will output the actuator position command in the increasing direction, but in this case, the second limiter 2LM cuts the command in the increasing direction.

FIG. 2 shows a second embodiment, and the only difference from the first embodiment of FIG. 1 is that the second limiter 2LM and the second switch 2SW are arranged between the controller PID and the first limiter 1LM. Since the basic structure and operation are the same as those in the first embodiment, the description thereof will be omitted.

[Effect of device]

As described above, the present invention switches each constant of the PID controller to a value having higher sensitivity than the normal value when the actual rotation speed becomes equal to or higher than the reference rotation speed close to the rated rotation speed. Since the limiter switched via the actuator position command cuts, it is possible to prevent overspeed of the main engine when sailing in the open sea in stormy weather.

[Brief description of drawings]

FIG. 1 is a block diagram of a first embodiment of the present invention, FIG. 2 is a block diagram of the same second embodiment, and FIG. 3 is a block diagram of a conventional example. OR …… commanded speed, FB …… actual speed OP …… calculator, PID …… PID controller 1LM …… first limiter, 2LM …… second limiter 1SW …… first switch, 2SW …… second Switch CO …… Comparator, LR …… Reference speed ACT …… Actuator, RA …… Fuel rack ENG …… Main engine, NS …… Normal sensitivity setter HS …… High sensitivity setter, SE …… Sensor

Claims (1)

[Scope of utility model registration request] 1. An arithmetic unit for obtaining a deviation between a command rotation speed and an actual rotation speed, a PID controller for performing proportional, integral, and differential operations on the deviation to output as an actuator position command, and the actuator of the PID controller. In a marine main engine control device equipped with an actuator that operates based on the position command output to control the fuel rack position, a reference rotation speed that is set higher than the rated speed of the main engine and lower than the overspeed detection speed. Comparing the number and the actual rotation speed, when the actual rotation speed is less than the reference rotation speed, a holding signal is output, and when the actual rotation speed is equal to or higher than the reference rotation speed, a comparator that outputs a switching signal, Each constant of the PID controller is set to a normal value based on the holding signal, and each constant of the PID controller is switched to a value having higher sensitivity than the normal value based on the switching signal. A first switch, and the actuator position command output from the PID controller is transmitted to the actuator based on the hold signal, and the actuator position command output from the PID controller based on the switching signal is passed through a limiter. A second switch for transmitting to the actuator is provided, and the limiter configured to pass by the switching signal but not by the holding signal allows only the actuator position command output in the decreasing direction or the current state to pass. A main engine control device for a ship, characterized in that