JP2541850B2 - Ultrasonic ship speed measuring device - Google Patents

Description

The present invention relates to an ultrasonic ship speed measuring device, and more specifically,
When measuring the ship speed by transmitting and receiving ultrasonic pulses, the Doppler frequency deviation is measured from the received signal and the first speed related to ground or water (hereinafter referred to as the ship speed, if necessary). Then, the second speed of the ship is calculated from the engine or shaft speed of the ship. Then, when foaming occurs and the value of the first speed decreases, the foaming of the foam occurs. By displaying the occurrence state of the ship and the second ship speed and sending it as a signal,
The present invention relates to a system device to which a signal of a ship speed value is provided, for example, an ultrasonic ship speed measuring device capable of effectively preventing functional deterioration related to operation of a radar or the like.

[Prior Art] Conventionally, in an ultrasonic ship speed measurement device mounted on a ship, an ultrasonic pulse is emitted into the sea from a transmitter via a transmitter / receiver arranged at the bottom of the ship. The ultrasonic pulse reflected from the target in the sea is received by the transmitter / receiver, and the ship speed is calculated from the Doppler frequency deviation of the signal obtained here. Furthermore, the value of the obtained ship speed is integrated to calculate the cruising distance, which is also displayed.

[Problems to be Solved by the Invention] However, this kind of ultrasonic ship speed measuring device has a drawback that it is easily affected by bubbles in transmitting and receiving ultrasonic pulses, like other ultrasonic devices. When installing a transducer on the bottom of a ship, it is difficult to find the optimum position that is not affected by bubbles, and even if the optimal position is determined, it cannot be installed at the optimum position because the shape of the transducer is large. There are cases. In such a case, the transmitted and received ultrasonic pulses are affected by the bubbles, and the correct ship speed value cannot be displayed. In particular, even in the case where the problem is not exposed in the plain water area, due to bubble clogging that sometimes occurs due to the state of cargo, sea conditions, etc., it may cause a drastic reduction from the actual value of the ship speed. The value of such ship speed is other system equipment, for example,
It is sent to NNSS, radar, data logger, etc. as ship speed information, and in such a case the operating function of the above system equipment will not be maintained normally.
In the operation of a ship based on the cooperation with these system devices, there will be a serious problem.

The present invention has been made in view of the above point, and displays a second ship speed calculated from a signal indicating an engine speed or a shaft speed, together with a normally obtained first ship speed, and a system device. By sending to the second
It is an object of the present invention to provide an ultrasonic ship speed measuring device that can minimize the adverse effects of other system devices that operate based on the ship speed.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides an ultrasonic ship speed measuring device including a transmitter and a receiver for transmitting and receiving ultrasonic pulses via a transceiver, The first to measure the Doppler frequency deviation from the received ultrasonic pulse and calculate the ship speed to the ground or to the water
And an input circuit to which a signal indicating the number of revolutions from an engine tachometer or a shaft tachometer of a ship is input, and an output from the input circuit and the first computing means in advance when bubble entrapment does not occur. A storage means for measuring and storing the relationship between the engine speed or the shaft speed and the ship speed based on the ship speed calculated by is referred to the storage content of the storage means based on the output from the input circuit. Second calculating means for calculating the ship speed, a comparator for comparing the ship speed calculated by the first calculating means with the ship speed calculated by the second calculating means, and a display for displaying the ship speed And when the ship speed calculated by the first calculating means has a difference of less than a predetermined value compared with the ship speed calculated by the second calculating means, the ship speed calculated by the first calculating means is Display on the display and outside However, when the ship speed calculated by the first calculating means has a difference of a predetermined value or more as compared with the ship speed calculated by the second calculating means, the ship speed calculated by the second calculating means is calculated. The display device and a switching device for outputting to the outside.

[Operation] In the ultrasonic ship speed measuring device of the present invention configured as described above, the second ship speed calculated by the first computing means is calculated based on the engine speed or the shaft speed.
When there is a difference of a predetermined value or more in comparison with the ship speed calculated by the calculating means, the ship speed calculated by the second calculating means is displayed and sent as an output signal. As a result, the influence on other system devices is suppressed to a minimum.

[Embodiment] An embodiment of an ultrasonic ship speed measuring device according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows the configuration of an embodiment of the present invention. In this example, a transmitter 12 for transmitting an ultrasonic pulse, a transmission / reception switching circuit 14, and an ultrasonic pulse transmitter / receiver 16 are further provided, and a receiver 18, a frequency counter 20, and a first counter are provided. An arithmetic unit (A) 22 as an arithmetic unit and an input circuit 26 to which a signal indicating the engine speed or the shaft speed is input. Further, it comprises a keyboard 28, a computing unit (B) 30 as a second computing means, a comparator 32, a switching unit 36 and a display unit 40.

Next, the measuring device of the present invention having the above structure will be described in detail with reference to FIGS.

First, the ultrasonic pulse generated by the transmitter 12 is supplied to the ultrasonic wave transmitter / receiver 16 via the transmission / reception switching circuit 14. The wave transmitter / receiver 16 emits an ultrasonic pulse obliquely downward in the bow direction, receives the reflected wave, converts the received reflected wave into an electric signal, and supplies the electric signal to the receiver 18. Then, the frequency counter 20 counts the Doppler frequency deviation of the reflected wave at the specified depth and further the Doppler frequency deviation of the seabed reflected wave, and the obtained data signal is calculated by the calculator (A).
Supply to 22. The calculator (A) 22 calculates the water speed V _{W of the} ship against the moving object in the water and the ground speed V _{B of the} ship against the sea bottom on the basis of the Doppler frequency deviation data, and calculates the calculated signal. (B) Supply to 30, comparator 32 and switch 36. Further, the computing unit (A) 22, to calculate the standard deviation indicating the variation of the data to water velocity V _W and ground speed V _B, and the standard deviation sigma _W of the derived signals respectively to water velocity V _W and The standard deviation σ _B of the ground speed V _B is supplied to the calculator (B) 30 and the comparator 32.

On the other hand, a rotation speed data signal obtained from an engine or a shaft tachometer (not shown) is supplied to an arithmetic unit (B) 30 via an input circuit 26. The calculator (B) 30 associates the relationship between the input water speed V _W and ground speed V _B and the rotation speed data signal. FIG. 2 shows these relationships. The data that should be the basic relationship are obtained during the speed test. The speed test is usually performed four times while changing the rotation speed, and in FIG. 2, R1, R2, R3, and R4 correspond to this. The ship speeds V1, V2, V3, and V4 at this time are the water speed V _W or the ground speed V _B input from the calculator (A) 22. These ship speeds are also keyboard 28 as values published by the shipyard.
It is also possible to input from. The computing unit (B) 30 calculates an approximate expression of the cubic curve a of the relationship between the rotation speed and the ship speed by the least squares method based on these values and stores it in the RAM or the like provided inside.

V = AR ³ + BR ² + CR + D (1) where V is the ship speed, R is the number of revolutions, and A, B, C and D are the calculated coefficients.

Here, during normal voyage, due to wind, tidal current, cargo conditions, etc., the ship speed does not match the approximate expression (1), and as shown in FIG. It is considered that there are variations. In FIG. 3, the curve b represents the upper limit of the variation, and the curve c represents the lower limit of the variation. In order to eliminate this variation, the computing unit (B) 30 corrects the approximation formula (1) from the rotational speed input at constant time intervals and the water speed V _W or the ground speed V _B.

The problem here is the accuracy of the water velocity V _W or the ground velocity V _B. Usually these speeds V _W or V _B are
Although the accuracy is ± 1% or less, when bubbles flow into the transducer surface, the frequency spectrum spreads, and the calculated ship speed value is generally smaller than the true value. In extreme cases, it is known that the value will be less than half the true value. The standard deviation σ _W of the water velocity V _W can be used as a measure of the state of the bubble clogging. That is, when bubble biting occurs, σ has a large value. Therefore, the computing unit (B) 30 prevents the abnormal data from being taken in by not performing the computation of the approximate expression (1) when the value of σ shows a certain value or more. I can.

On the other hand, the comparator 32 compares the water speed V _W or the ground speed V _B input from the computing unit (A) 22 with the ship speed V input from the computing unit (B) 30, and the difference between them is determined. A switching signal for outputting the water speed V _W or the ground speed V _B when the value is equal to or lower than a predetermined value is supplied to the switch. Further, a switching signal for outputting the boat speed V is supplied to the switching device 36 even when the value is equal to or more than the predetermined value. Based on the switching signal, the switch 36 performs an operation of supplying a signal indicating the water speed V _W or the ground speed V _B to the display 40 or supplying a signal indicating the ship speed V. Further, when the signal indicating the ship speed V is supplied, it is affected by the bubbles, and therefore the ship speed V is calculated and displayed based on the rotation speed of the engine tachometer or the shaft tachometer. Is also supplied to the display 40.

When such a rotation speed and a true ship speed are obtained in advance, the data is transferred via the keyboard 28 to the computing unit (B).
It is also possible to enter in 30.

[Effects of the Invention] As described above, according to the ultrasonic ship speed measuring device of the present invention, the Doppler frequency deviation is measured from the received signal,
The ship speed to the ground or water against the traveling ship is calculated by the first calculating means, and further the ship speed is calculated by the second calculating means based on the engine speed of the ship foil or the shaft speed.
When the value of the ship speed calculated by the first calculating means has a difference of a predetermined value or more as compared with the ship speed calculated by the second calculating means, the ship speed calculated by the second calculating means is set. By displaying and sending out as a signal, the system equipment to which the value of the ship speed is provided, for example, NNSS, radar,
This has the effect of preventing functional deterioration of data loggers and the like.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing an embodiment of a ship speed measurement and display device according to the present invention, FIG. 2 is an explanatory view showing the relationship between the rotation speed and the ship speed, and FIG. 3 is a graph showing the rotation speed and the ship speed. It is explanatory drawing which shows the relationship with upper and lower limits. 12 …… Transmitter, 14 …… Transmit / receive switching circuit 16 …… Transmitter / receiver, 18 …… Receiver 20 …… Frequency counter, 22 …… Calculator (A) 26 …… Input circuit, 28 …… Keyboard 30 …… Calculator (B), 32 …… Comparator 36 …… Switch, 40 …… Display

Claims (1)

(57) [Claims] 1. An ultrasonic ship speed measuring apparatus including a transmitter and a receiver for transmitting and receiving ultrasonic pulses via a transmitter / receiver, measuring the Doppler frequency deviation from the received ultrasonic pulses, and sailing the ship. The first calculation means for calculating the ship speed against the ground or against the water, the input circuit to which a signal indicating the number of revolutions from the engine tachometer or the shaft tachometer of the ship is input, and in advance when bubble entrapment does not occur. An output from the input circuit has a storage means for measuring and storing the relationship between the engine speed or shaft speed and the ship speed based on the output from the input circuit and the ship speed calculated by the first computing means. Second calculation means for calculating the ship speed by referring to the stored contents of the storage means based on the above, and the ship speed calculated by the first calculation means and the ship speed calculated by the second calculation means. Comparator to compare And an indicator for displaying the boat speed, and the first unit when the boat speed calculated by the first computing unit has a difference of less than a predetermined value compared with the boat speed calculated by the second computing unit. The ship speed calculated by the calculating means is output to the display and the outside, and the ship speed calculated by the first calculating means is equal to or more than a predetermined value compared with the ship speed calculated by the second calculating means. If the second
An ultrasonic ship speed measuring device comprising: the display device and a switcher for outputting the ship speed calculated by the calculating means to the outside.