JPH0592771U - Ship speed measuring device - Google Patents

Abstract

(57) [Abstract] [Purpose] Transmission and reception can be performed alternately in the front and rear, and the processing unit of the received signals in the front and the rear can be made common to simplify the circuit configuration, and at the time of stop or low speed. (EN) Provided is a ship speed measuring device capable of accurately displaying speed. [Structure] An ultrasonic beam is emitted in each of the directions diagonally forward and backward of the vessel, and the reflected waves from the water mass at a position far from the bottom of the vessel are received to detect the Doppler shift and to determine the vessel speed. In the ship speed measuring device for measurement, the averaging processing means for accumulating and averaging the detected Doppler shift data at fixed time intervals is provided, and the forward / backward movement is discriminated, and the Doppler shift data advances in the reverse direction. When the polarity is set, the forward / backward movement determining means for outputting a subtraction command to the averaging processing means is provided and configured.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention emits an ultrasonic beam in each of the diagonally forward and diagonally backward directions of the ship, receives the reflected waves from the water mass located at a position far from the bottom of the ship, and detects the Doppler shift, The present invention relates to a water-type ship speed measuring device for measuring ship speed.

[0002]

[Prior Art]

 In general, a ship speed measuring device that uses the Doppler effect is configured to emit ultrasonic beams simultaneously in the diagonally forward and diagonally backward directions of the ship in order to avoid the effects of hull pitching. FIG. 9 shows an example of a conventional ship speed measuring device of this type.

The conventional ship speed measuring device shown in FIG. 1 includes an original oscillation unit 10, front and rear transmission units 12 _F and 12 _A , and front and rear transmission / reception switching units 14 _F and 14 _A. Front and rear transducers 16 _F and 16 _A , front and rear receivers 18 _F and 18 _A , front and rear frequency detectors 20 _F and 20 _A , It is configured by including a calculation unit 22 provided in common in the front and rear and a ship speed display unit 24.

In this conventional ship speed measuring device, the excitation current shaped into a pulse signal in the original oscillator 10 is amplified and transmitted in the corresponding transmitters 12 _F and 12 _A for the front and the rear. _A narrow ultrasonic beam is emitted from the transducers 16 _F and 16 _A through the switching units 14 _F and 14 _A at a constant depression angle in the sea diagonally forward and diagonally behind the ship. Then, the scattered reflection signal from the water mass located at a distance of about several meters from the bottom of the ship is received by the transducers 16 _F and 16 _A and converted into an electric signal, and passed through the transmission / reception switching units 14 _F and 14 _A. , Input to the receivers 18 _F and 18 _A. The receivers 18 _F and 18 _A amplify the received signal to the required level, the frequency detectors 20 _F and 20 _A detect the Doppler shift in each direction, and the calculator 22 converts this signal into a ship speed signal. Along with the conversion, the averaging process is performed and this is displayed on the ship speed display unit 24.

[0005]

[Problems to be solved by the device]

 However, since this conventional ship speed measuring device is configured to emit ultrasonic waves to the front and the rear of the ship at the same time, when the reflected wave is received, the received signal is processed independently for the front and the rear. Therefore, it is necessary to double the circuits up to the front stage of the calculation unit 22 for the front and rear circuits. In particular, it is necessary to double the frequency detector, which is the center of the ship speed measurement device.

As a result, the circuit configuration becomes complicated, the number of components increases, and a large printed circuit board or the like on which these components are mounted is required.

On the other hand, the instantaneous value of the received signal is not a stable value and has a great variation. Therefore, even in the conventional ship speed system, the received signals are displayed by integrating them for a certain period of time and averaging them.

By the way, when the ship is stopped or at a very low speed, the instantaneous value of the received signal is often a forward signal or a reverse signal. However, in the conventional ship speed measuring device, when the forward and backward signals are input alternately or in a state close to this, the speed instructions are displayed larger than they are because they are integrated as they are. There is a drawback.

The present invention has been made to solve the above-mentioned drawbacks, and transmission and reception can be alternately performed in the front and the rear, and the processing unit for the received signals in the front and the rear is made common to simplify the circuit configuration. It is an object of the present invention to provide a ship speed measuring device capable of displaying an accurate speed even when the ship is stopped or at a very low speed.

[0010]

[Means for Solving the Problems]

 The present invention emits an ultrasonic beam in each of the diagonally forward and diagonally backward directions of the ship, receives the reflected waves from the water mass located at a position far from the bottom of the ship, and detects the Doppler shift, In a ship speed measuring device for measuring ship speed, as means for solving the above problems, (a) a transmission / reception switching means for setting the emission timing is provided so as to alternately emit ultrasonic waves forward and backward, and (b) ) A reception signal processing means for detecting the Doppler shift from the reception signals of the reflected waves received from the front and the rear to measure the ship speed is provided for both front and rear, and (c) the reception signals received from the front and the rear, respectively. Is provided with a switching means before and after reception which is connected to the reception signal processing means in synchronism with the emission timing, and (d) the received signal processing means is integrated with the detected Doppler shift data at regular time intervals and averaged. Turn into In addition to providing averaging processing means, it is configured by providing forward / backward movement determining means for performing forward / backward movement determination and outputting a subtraction command to the averaging processing means when the Doppler shift data has a polarity that advances in the reverse direction. It is characterized by

[0011]

[Action]

 By the way, in the case of a water-type ship speed measuring device, if the target object is a water mass several meters away from the bottom of the ship, the echo of the ultrasonic waves emitted will return after a few milliseconds. Therefore, the transmission may be repeated every 20 ms (50 Hz). This time of about 20 ms is extremely short compared to the pitching cycle of the hull, so if ultrasonic waves are not emitted forward and backward at the same time, even if they are alternately transmitted and received, simultaneous firing for pitching is possible. Has the same effect as. The present invention is based on such knowledge.

That is, the transmission / reception switching unit emits ultrasonic waves alternately forward and backward, and the reception signals received from the front and the rear are synchronized by the reception front / rear switching unit with the emission timing. It is connected to the received signal processing means. The reception signal processing means for detecting the Doppler shift from the reception signals of the reflected waves respectively received from the front and the rear and measuring the ship speed is provided in common for both front and rear sides and is shared by both.

As a result, the number of circuits conventionally provided in duplicate is sufficient, and the circuit configuration can be simplified.

Further, according to the present invention, by integrating the Doppler shift data and averaging the data, variations in instantaneous values are absorbed, and stable speed display is possible. Moreover, at that time, the forward / backward movement of the vessel is determined, and when the forward / reverse traveling signals are disturbed and input, such as when the vessel is stopped or at a slow speed, the signal in the opposite direction to the signal to be integrated is subtracted. As a result, accurate speed display can be performed.

[0015]

【Example】

 An embodiment of the present invention will be described with reference to the drawings.

<Structure of Embodiment> FIG. 1 shows the structure of a first embodiment of a ship speed measuring device according to the present invention.

The ship speed measuring device of the embodiment shown in FIG. 1 includes an original oscillating unit 26, front and rear transmission units 12 _F and 12 _A , and front and rear transmission / reception switching units 14 _F , 14 _A , front and rear transducers 16 _F and 16 _A , front / rear switching unit 28, front / rear common receiving unit 18, frequency detection unit 56, calculation unit 58, and ship speed display And a section 60.

In the present embodiment, the original oscillating unit 26 and the front / rear switching unit 28 constitute a front / rear switching unit for transmission and a front / rear switching unit for reception, and the receiving unit 18, the frequency detecting unit 56, the calculating unit 58 and the ship speed. The display section 60 is characterized in that the display section 60 is commonly provided in both front and rear directions as a reception signal processing means. Further, it is characterized in that the arithmetic unit 58 is provided with an averaging processing means and a forward / backward movement determining means. On the other hand, the configuration of the other parts is basically the same as that of the conventional ship speed measuring device shown in FIG. Therefore, in the following, the characteristic part of the present embodiment will be mainly described.

The original oscillating unit 26 is configured, for example, as shown in FIG. 2A. That is, the original oscillating unit 26 includes a transmission frequency oscillator 30, a pulse repetition frequency oscillator 32, a transmission pulse width setting circuit 34, a depth position determination circuit 36, a reception gate setting circuit 38, a frequency divider 40, and an amplifier. Gate circuits 42, 44 and 46.

The transmission frequency oscillator 30 sets a frequency for exciting the ultrasonic transducer for wave transmission. On the other hand, the pulse repetition frequency oscillator 32 generates pulses that set the repetition frequency for transmitting ultrasonic waves.

The transmission pulse width setting circuit 34 is composed of, for example, a monostable multivibrator, and outputs a pulse corresponding to the transmission pulse width by using the pulse from the pulse repetition frequency oscillator 32 as a trigger. The depth position determination circuit 36 is composed of, for example, a monostable multivibrator, and uses the above-mentioned transmission pulse as a trigger to set the depth position and the position of the water mass from the bottom of the ship where reflections should be received, and determines the start timing of the reception gate. Output the pulse. Similarly, the reception gate setting circuit 38 is also composed of a monostable multivibrator, and uses the reception gate start timing determination pulse as a trigger to form a pulse for setting a sampling gate that receives a reception wave, and this is used for frequency detection. It is sent to the output unit 56.

On the other hand, the frequency divider 40 is composed of, for example, a T flip-flop circuit, and alternately outputs a high level transmission gate signal to Q and * Q by using the pulse from the pulse repetition frequency oscillator 32 as a trigger. .. (Here, * represents a signal of negative logic and is shown with an overline in the drawing.) In the AND gate circuit 42, the transmission frequency oscillator 30 and the transmission pulse width setting circuit 34 are connected to the input. The pulse output from the latter becomes a gate signal, and the former excitation current is sent from the former to the AND gate circuits 44 and 46 for a time corresponding to the pulse width. The AND gate circuits 44 and 46 are alternately input with the transmission gate signals from the frequency divider 40 and alternately output the transmission excitation currents to the corresponding transmission units 12F, 12A.

The front / rear switching unit 28 includes a switch drive circuit 48 and a switch 50. The switch driving circuit 48 receives the Q and * Q outputs from the frequency divider 40 and outputs a switching control signal for the switch 50. The switch 50 is composed of, for example, a semiconductor switch circuit as shown in FIG. 2B. That is, the switch 50 includes a PIN diode D ₁ , a forward circuit 52 including capacitors C ₁ and C ₄ and an inductance L ₁ and a PIN diode D 1.
₂ , a rear system circuit 54 composed of capacitors C ₂ , C ₅ and an inductance L ₂ , and a capacitor C ₃ and an inductance L ₃ common to both.

Here, a reflected wave signal is input to the input terminal F _IN from the front of the ship. On the other hand, the reflected wave signal is input to the input terminal A _IN from the rear of the ship. Further, a control signal corresponding to the Q output from the frequency divider 40 is input from the switch drive circuit 48 to the control terminal C _tF .

On the other hand, a signal corresponding to the * Q output from the frequency divider 40 is input from the switch drive circuit 48 to the control terminal C _tA . The switch 50 is a changeover switch that utilizes the fact that the PIN diode of the two PIN diodes, to which the control signal is supplied from the control terminal, conducts the high-frequency signal. A reception signal is sent from the cathode of the diode D ₁ or D ₂ to the common reception unit 18 from the output terminal O _t via the capacitor C ₃ .

As shown in FIG. 3, the frequency detecting section 56 includes a gate signal forming section 62 including D flip-flop circuits 66 and 68, counters 70 and 72, and a clock generator 64, an exclusive OR gate circuit 76 and A velocity pulse forming section 74 including a NAND gate circuit 78 and a reverse pulse forming section 80 including exclusive OR gate circuits 82 and 84 and a NAND gate circuit 86 are provided. The frequency detector 56 receives a velocity pulse from the reception gate G _R from the original oscillator 26, the reference clock C _S from the clock generator 64, and the reception signal input via the front / rear switching unit 28. * P _V and backward pulse * P _A are formed.

As shown in FIG. 4, the calculation unit 58 and the ship speed display unit 60 include a pre-up / down counter 88 and an up / down counter 90 that form an averaging processing unit, a forward / backward movement determination circuit 92, and a numerical display. The display device 94 and the reverse display device 96 are provided as basic elements. Further, in the present embodiment, as an additional circuit, a speed data transmission circuit 98, a speed comparison circuit 102, a speed alarm device 100 including a speed setting switch 104 and a buzzer 106, and 200 P / An M relay 110 and a route counter 114 are further connected via a frequency divider 112.

The pre-up / down counter 88 counts the speed pulse * P _V in accordance with the count-up signal U or the count-down signal D from the forward / backward movement discriminating circuit, which will be described later, and the speed signal * is calculated according to a preset division ratio. Output P _S. The division ratio can be changed by a digital switch (not shown).

The up / down counter 90 functions as a decoder that divides the speed signal * P _S to convert it from a binary number to a decimal number.

The numeral display 94 displays the speed converted into a decimal number by the up / down counter 90 by a numeral. The numerical indicator 94 is additionally provided with a reverse indicator 96 which is turned on by a reverse indicator signal from the forward / reverse discriminating circuit 92.

As shown in FIG. 5, the forward / backward movement determination circuit 92 includes an inverter 116, a P _A edge detection circuit 118, a D flip-flop circuit 120, an exclusive OR gate circuit 122, a latch circuit 124, and a timing circuit. A circuit 126 and an up / down counter group 89 composed of the pre-up / down counter 88 and the up / down counter 90, and a switching signal U / D for up / down counting, and a reverse display 96. The reverse display signal is output to.

The P _A edge detection circuit 118 is composed of, for example, a monostable multivibrator, is triggered by the trailing edge of the backward pulse * P _A , outputs a negative pulse from the * Q terminal, and outputs the negative pulse from the D flip-flop circuit 120. Send to set terminal * S.

The latch circuit 124 is composed of, for example, a D flip-flop circuit, and latches the output of the Q terminal of the D flip-flop circuit 120.

The timing circuit 126 supplies the latch timing of the latch circuit 124, that is, the sampling strobe signal in a constant cycle, and sends the reset signal to the reset terminal * R of the D flip-flop circuit 120 in a constant cycle.

<Operation of Embodiment> The operation of the present embodiment will be described with reference to the above-mentioned drawings and FIGS. 6 and 7.

In the original oscillating unit 26, the transmission frequency oscillator 30 generates a transmission frequency signal for exciting the ultrasonic transducer. This signal has a frequency of 2 MHz in this embodiment. Further, as shown in FIG. 6, the pulse repetition frequency oscillator 32 oscillates at a frequency twice as high as the transmission repetition period, and outputs this output R _P to the transmission pulse width setting circuit 34 and the frequency divider 40.

The transmission pulse width setting circuit 34 uses this output R _P as a trigger to set a transmission pulse width having a preset time width of 2 ms. The transmission pulse width signal W _P is sent to the AND gate circuit 42 and the depth position determining circuit 36.

In the AND gate circuit 42, the transmission frequency signal is put in the above transmission pulse width to form a transmission pulse T _P , which is sent to the AND gate circuits 44 and 46.

Further, the depth position determination circuit 36 is a circuit for setting the water depth to be detected as a reflected wave, and in the present embodiment, the sound velocity is taken into account as a reflected wave at a water depth of about 3 m is detected. , 4 ms pulse width is set. With this depth position determination pulse D _P , the reception reference setting gate signal G _R is formed in the reception gate setting circuit 38 and sent to the frequency detection unit 56.

On the other hand, the frequency divider 40 divides the repetition period by half to form the front-rear direction switching signals G _FA and * G _FA , which are then AND gate circuits 44, 46 and the switch drive circuit. Send to 48. The front-rear direction switching signal G _FA is set to about 10 ms in this embodiment.

In the AND gate circuits 44 and 46, the gates are alternately opened by the front-rear direction switching signals G _FA and * G _FA , the transmission pulse T _P is separated in the front-rear direction, and the burst pulse (T _F , 2 ms, 2 ms, As T _A ), it is sent to the corresponding transmission units 12F and 12A every 20 ms.

Transmission unit 12_F , 12_A Then, this is power-amplified and output as an output pulse of, for example, about 20 W, and transmitted / received by the corresponding transmission / reception switching units 14F, 14A. _F , 16_A Have been sent to.

The front and rear transducers 16 _F and 16 _A convert the power pulses into ultrasonic waves and radiate them into water.

The ultrasonic beam radiated into the water is scattered when it hits innumerable minute plankton, sand grains, bubbles, etc. floating in seawater, and among them, the sound waves returning to the direction of the receiver are scattered. It becomes a received signal. If there are relative velocities between these suspended solids and the ship, the frequency of the received wave will be Doppler-shifted due to the Doppler effect.

The received wave is converted into an electric signal in each of the front and rear transducers 16 _F and 16 _A , and is sent to the front / rear switching unit 28 via the transmission / reception switching units 14 F and 14 _A.

In the front / rear switching unit 28, as shown in FIG. 2B, the received signal of the reflected wave from the front is input to the input terminal F _IN, and the received signal of the reflected wave from the rear is input to A _IN . Here, for the control terminals C _tF and C _tA , the front-back direction switching signals G _FA and * G _FA from the frequency divider 40 are respectively amplified by the switch drive circuit 48, and the Q output G _FA is controlled. The * Q _FA of * Q output is input to the terminal C _tF corresponding to the control terminal C _tA .

Here, when Q is at a high level, a current flows through the path of the coil L ₁ , the PIN diode D ₁ and the coil L ₃ , and as a result, the high frequency impedance of the PIN diode D ₁ decreases and the input The signal from the terminal F _IN is output to the receiving unit 18 via the capacitor C ₃ .

On the other hand, when * Q is at a high level, a current flows through the path of the coil L ₂ , the PIN diode D ₂ and the coil L ₃ , and as a result, the high frequency impedance of the PIN diode D ₂ decreases and the input The signal from the terminal A _IN is output to the receiving unit 18 via the capacitor C ₃ .

The receiving unit 18 adopts the super-heterodyne system, and the frequency of 2 MHz ± fd of the received signal including the Doppler shift fd is converted to the intermediate frequency (200 KHz ± fd in this embodiment by the local oscillation signal of 1.8 MHz). ), Amplify it sufficiently, and output a TTL level square wave.

Next, the frequency detector 56 detects the Doppler shift in each direction.

This detection method is a counting method, in which a fixed number (200) of the output 200 KHz ± fd of the receiving unit 18, which is a received signal, and the reference clock C _S are counted, and the required time difference is the Doppler shift. The Doppler shift is detected by finding the time difference using the fact that it is proportional to.

The rectangular-wave-shaped received signal is input to the D flip-flop circuits 66 and 68 of the frequency detector 56 shown in FIG. 3 and the clock terminal C _K of the counter 70.

When the reception gate signal G _R and the reception signal are input to the D flip-flop circuits 66, 68, the flip-flop circuits 66, 68 respectively measure the measurement gate time signal G _S and the reference gate time signal G Output _r . These serve as enable signals for the corresponding counters 70 and 72, the counter 70 counts the received signal, and the counter 72 counts the reference clock C _S. When the counters 70 and 72 count up to preset values (in the present embodiment, the former is 200 and the latter is 9000), they output count end signals.

This end signal resets the corresponding D flip-flop circuits 66 and 68. Each of the gate time signals G _S and G _r causes a difference in its gate time unless the received signal and the reference clock match. In this embodiment, the reference gate time G _r is set to 1 ms.

The gate time signals G _S and G _r are input to the exclusive OR gate circuit 76. The output of the exclusive OR gate circuit 76 becomes the difference gate G _F when G _S ≠ G _r , and in that case, in the NAND gate circuit 78, in accordance with the difference between G _{S and} G _r , the clock generator 64 The reference clock C _S (for example, 9 MHz) from is passed through with its polarity inverted. This output is the speed pulse * P _V.

On the other hand, the measurement gate time signal G _S and the front-rear direction switching signal G _FA are exclusive to the OR gate circuit 82, and the reference time gate signal G _r inverted signal * G _r and the front-rear direction switching signal G _FA are exclusive. Input to the OR gate circuit 84. Then, the outputs of the exclusive OR gate circuit 82 and the exclusion OR gate circuit 84 are input to the NAND gate circuit 86. Here, when the measured gate time signal G _S of the received signal from the front is longer than the reference gate time signal G _r , or when the measured gate time signal G _S of the received signal from the rear is the reference gate time signal G _r When it is shorter, the outputs of the exclusive OR gate circuit 82 and the exclusive OR gate circuit 84 both become high level corresponding to the time difference, and the reverse gate pulse * P from the NAND gate circuit 86 indicates that the ship is moving backward. _A is output.

The number of speed pulses * P _V is proportional to the Doppler shift, and the sum of the forward Doppler shift and the rear Doppler shift is proportional to the speed of the ship. In this embodiment, this is integrated for a certain period of time (sample time T _S ) and the instantaneous speed is averaged to obtain the average speed. In this embodiment, the sample time T _S is set to 10 seconds and the sample strobe signal is output from the timing circuit 126 once every 10 seconds.

By the way, the instantaneous value of the received signal is not a stable value and has a great deal of variation. Therefore, if the integrated counting is performed as it is, the backward signal (reverse signal) is also integrated when the ship is stopped or at a slow speed. However, the speed instruction will be bigger than it really is. In order to eliminate this, in the case of signals in the opposite direction, it is necessary to perform subtraction and integration. Therefore, this integration is performed by the pre-up / down counter 88 and the up / down counter 90 of the arithmetic unit 58. The pre-up / down counter 88 is set to a division ratio so that the display speed matches the actual speed. This frequency division ratio is set so that it can be easily variably set using a digital switch, etc., in order to eliminate errors due to the trim of the hull.

The up / down counter 90 further divides the output * P _S of the pre-up / down counter 88 and converts it into a 4-digit decimal number. The data of the up / down counter 90 is latched after the sample time T _S and sent to the numeral display 94 and the speed data sending circuit 98 as display data.

On the other hand, the forward / backward movement determination circuit 92 determines the forward / backward movement of the ship using the backward movement pulse P _A.

The latch circuit 124 of the forward / reverse determination circuit 92 samples and latches the output of the Q terminal of the flip-flop circuit 120 according to the sample strobe signal from the timing circuit 126. The flip-flop circuit 120 is reset by the reset signal output from the timing circuit 126 immediately after this sample strobe signal. The sample strobe signal and the reset signal are set with a cycle as the sampling time T _S, and in this embodiment, they are set to 10 seconds.

After the flip-flop circuit 120 is reset, the reverse pulse * P _A is not output while the ship is moving forward, so the flip-flop circuit 120 remains reset, and the up-down counter group 89 is Count up. In this case, even if the next reset signal is input, the flip-flop circuit 120 does not change its state and the up-count state continues as it is. At this time, the latch circuit 124 latches the output of the Q terminal of the flip-flop circuit 120 by the sample strobe signal, but since the Q terminal is at the low level, backward display is not performed.

On the other hand, since the reverse pulse * P _A is always output while the ship is in reverse, the flip-flop circuit 120 is set by the output pulse of the P _A edge detection circuit 118, and the output from the * Q terminal is output. Becomes low level. In this state, in the exclusive OR gate circuit 122, the backward pulse P _A whose polarity has been inverted by the inverter 116 is input, so that the counter group 89 continues to count up.

Here, when the sample strobe signal is input, since the flip-flop circuit 120 is set, the high level state of its Q terminal is latched by the latch circuit 124. Then, it is output as a reverse display signal from the latch circuit 124 to light the reverse display 96.

By the way, in the vicinity of 0 knot where forward and reverse are mixed, when the sample strobe signal is finally input, if the flip-flop circuit 120 is set, it will be reverse, and if it is not set, it will be forward. .. Therefore, consider the case where forward and backward signals come to the random.

When the backward pulse * P _A is input, the flip-flop circuit 120 enters the set state due to the output of the P _A edge detection circuit 118. Therefore, a reset signal is input later, or a clock signal is input. Until you do that, the state does not change. Therefore, when the forward pulse signal is input (the reverse signal is not input) after the reverse pulse * P _A is input, the * Q terminal of the flip-flop circuit 120 is at the low level. The inputs are in phase and the output becomes a low-level countdown signal.

In this state, when the forward movement signal is input more than the backward movement signal, the counter group 89 continues the subtraction, the count value becomes “0”, and a signal to that effect is output. On the other hand, when the forward drive signal is less than the reverse drive signal, the difference obtained by subtracting the forward drive signal from the reverse drive signal is the reverse drive speed.

The “0” output signal is input to the clock terminal C _K of the flip-flop circuit 120. As a result, the flip-flop circuit 120 is set or reset according to the input signal at the D terminal at that time.

Here, assuming that the forward signal is input, the flip-flop circuit 120 changes to the reset state. After that, the same operation as described above is performed. On the other hand, assuming that a backward signal is input, the flip-flop circuit 120 continues to be in the set state, and the latch circuit 124 latches the high level state of the Q terminal and outputs the backward display signal.

By the way, the present embodiment is provided with a speed warning device, a lane counter and the like. Next, these actions will be described.

First, the alarm device receives speed data as serial data from the speed data transmission circuit 98 once every sampling time T _S , and latches the speed data to the speed comparison circuit 102. The speed comparison circuit 102 compares this data with the data input from the speed alarm setting switch 104, and outputs an alarm signal and sounds the buzzer 106 when the speed is higher or lower than the preset data. ..

Further, the 200P / M relay 110 outputs the pulse of 200 pieces per 1 mile by the pulse obtained by dividing the output of the pre-up / down counter 88 by the divider 108.

Further, the lane counter 114 further divides the output of the frequency divider 108 into a unit distance signal, counts the number, and displays the cruising distance of the vessel.

<Modification of Embodiment> In the above embodiment, the front / rear switching unit is arranged in the front stage of the receiving unit, but it may be arranged in the rear stage of the receiving units 18F and 18A as shown in FIG.

Further, in the above embodiment, the switch of the front / rear switching unit 28 is configured by the PIN diode circuit, but the present invention is not limited to this, and it may be configured by an FET, a bipolar transistor, or the like. Further, as described above, when the front / rear switching unit 28 is arranged in the subsequent stage of the receiving units 18F and 18A, since the receiving unit output is at the logic level, the front / rear switching unit 28 has a simple gate and analog It can be configured with a switch or the like.

Further, in the above embodiment, the counter of the arithmetic unit is composed of the pre-up / down counter and the up / down counter, but they may be connected in series to form an integrated up / down counter.

[0077]

[Effect of the device]

 INDUSTRIAL APPLICABILITY As described above, according to the present invention, transmission and reception can be alternately performed in the front and the rear, the processing unit for the received signals in the front and the rear can be made common, and the circuit configuration can be simplified. There is an effect that an accurate speed display can be performed even at times.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a ship speed measuring device according to the present invention.

FIG. 2 is a block diagram showing a configuration of an original oscillating section and a front / rear switching section which constitute the above embodiment, and FIG. 2 is a circuit diagram showing an example of the front / rear switching section.

FIG. 3 is a block diagram showing a configuration of a frequency detection unit that constitutes the above embodiment.

FIG. 4 is a block diagram showing the configuration of an arithmetic unit that constitutes the above embodiment.

FIG. 5 is a block diagram showing a configuration of a forward / backward movement determination circuit which constitutes the arithmetic unit.

FIG. 6 is a time chart showing the operation of the original oscillator shown in FIG. 2A.

7 is a time chart showing the operation of the frequency detection unit shown in FIG.

FIG. 8 is a block diagram showing a configuration of a ship speed measuring device which is a modified example of the present embodiment.

FIG. 9 is a block diagram showing a configuration of a conventional ship speed measuring device.

[Explanation of symbols]

12F, 12A ... Transmission unit, 14F, 14A ... Transmission / reception switching unit, 16F,
16A ... Transceiver, 18,18F, 18A ... Reception section, 26 ... Original oscillation section, 28 ... Front-back switching section, 30 ... Transmission frequency oscillator, 32 ... Pulse repetition frequency oscillator, 34 ... Transmission pulse width setting circuit,
36 ... Depth position determination circuit, 38 ... Reception gate setting circuit, 40 ...
Frequency divider, 48 ... Switch drive circuit, 50 ... Switch, 56 ... Frequency detection section, 58 ... Calculation section, 60 ... Ship speed display section, 62 ... Gate signal forming section, 64 ... Clock generator, 66, 68 ... D Flip-flop circuit, 70, 72 ... Counter, 74 ... Velocity pulse forming unit, 80 ... Reverse pulse forming unit, 88 ... Pre-up / down counter, 90 ... Up-down counter, 92 ... Forward / backward discrimination circuit, 94 ... Numeric display, 96 ... reverse display, 98 ... speed data transmission circuit, 100 ... speed alarm device.

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[Procedure amendment]

[Submission date] March 19, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 5

[Correction method] Change

[Correction content]

[Figure 5]

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. An ultrasonic beam is emitted in directions diagonally forward and diagonally backward of a ship, and a reflected wave from a water mass located away from the bottom of the ship is received to detect a Doppler shift, In a ship speed measuring device for measuring speed, (a) transmission / reception switching means for setting the emission timing is provided so that ultrasonic waves are alternately emitted forward and backward, and (b) signals are received from the front and rear respectively. The reception signal processing means for detecting the Doppler shift from the reception signal of the reflected wave and measuring the ship speed is provided in common for the front and rear, and (c) the reception signals received from the front and the rear, respectively, are synchronized with the launch timing. Providing a switching means before and after reception connected to the reception signal processing means, (d) the reception signal processing means is provided with an averaging processing means for integrating and averaging the detected Doppler shift data at regular time intervals. Both , By performing forward and reverse discrimination, when the Doppler shift data is a polar traveling in the opposite direction,
A ship speed measuring device comprising a forward / backward movement determining means for outputting a subtraction command to the averaging processing means.