JPS60227181A - Hyperbolic navigation system - Google Patents

Abstract

PURPOSE:To improve the reception precision of a Decca receiver by inserting an additional pattern with short time width into each transmitted pattern and synchronizing phases of respective transmitted patterns. CONSTITUTION:When the pattern signal receiving circuit 14 of the Decca receiver receives a main transmitted pattern and two slave transmitted patterns, a 90 deg. phase detecting circuit detects a pattern with short time width inserted additionally into each transmitted pattern to discriminated between the main pattern and slave pattern. The circuit 14 is controlled through a timing circuits 13 which reacts to the decision output to select substitute oscillators 16-18 corresponding to patterns to speed up the acquisition of synchronism for received patterns, and then the frequency of the acquisition of synchronism is increased to widen the range of the acquisition of synchronism, thereby improving the reception precision. Consequently, phase measurement precision is improved and a reception position is determined accurately.

Description

DETAILED DESCRIPTION OF THE INVENTION (a+) Technical Field of the Invention The present invention relates to an improvement in a hyperbolic navigation system used in the Detsuka navigation system and the like.

(b) Prior Art and Problems The Detsuka Old-Fix navigation, known as one of the radio navigation systems, uses a hyperbolic navigation system. This method consists of a main transmitting station and two sub-transmitting stations, each of which is placed at a predetermined distance from a measurement point.
Pattern signals unique to each transmitting station are transmitted at the same frequency at predetermined time intervals in order to form a deep pattern signal.

On the other hand, the ship while sailing receives the Detsuka pattern signals emitted from the upper and two slave transmitting stations using the onboard Detsuka receiver, and detects the phase difference between the master station pattern signal and each slave station signal. Lane identification is then performed by comparing the detected phase difference with a hyperbolic chart (Detsuka chart), and the position of the own ship is determined from the intersection of the two identified lanes. Therefore, in such a hyperbolic navigation system, it is necessary for the DETSUKA receiver to accurately receive the pattern signals transmitted from each transmitting station. , main and slave transmitters as shown in the block diagrams of FIG. 2 (δ) and FIG. 2 fbl, and a receiver as shown in the block diagram of FIG. 3 were used.

That is, as shown in the block diagram of FIG. 2 (81), the main transmitter generates a trigger signal by the trigger signal generator 1, outputs it to the switching circuit 3 and the timing circuit 4, and
A pattern signal is generated by the pattern signal generator 2 and output to the switching circuit 3. The timing circuit 4 detects the leading edge of the input trigger signal, and the switching circuit 3 outputs the trigger signal and the main station pattern signal M at the timing shown at 81 in FIG. 1 using the leading edge as a reference. control.

The trigger signal output from the switching circuit 3 and the main station pattern signal M are modulated to a predetermined transmission frequency by the transmission circuit 5 and transmitted to the outside via the transmission antenna 6.

Further, the transmitters of slave station 1 and slave station 2 generate a pattern signal by a pattern signal generator 2 and output it to a switching circuit 3, as shown in the block diagram of FIG. The reception antenna 7 receives the main station transmission wave and outputs it to the trigger detection circuit 8. The trigger detection circuit 8 detects the trigger signal of the received main station transmission wave and outputs it to the timing circuit 9. The timing circuit 9 uses the trigger signal as a reference time, and the timing circuit 9 uses the trigger signal as a reference time.
The switching circuit 3 is controlled so as to output the pattern signal S1 of the slave station 1 and the pattern signal S2 of the slave station 2 at timings having a predetermined time interval as shown in 2 and A3. The slave pattern signals S1 and S2 outputted from the switching circuit 3 are transmitted to the outside via the transmitting circuit 5 and the transmitting antenna 6, respectively.

Conventionally, the signal timing of the big pattern signals transmitted from the main station and the two slave stations mentioned above is as shown in Fig. 1. First, the trigger signal is output as Looms, and then the main station pattern signal M is output at 20 Qms at intervals of 50 m5. The slave station signal S
l is outputted for 200m5 hours, and further, at an interval of 100m5 hours, the slave signal S2 is outputted for 200m5 hours,
A trigger signal, which is the first signal, is output again at an interval of 50 m5 time. After that, 1 at the above timing.
The transmission of each signal is repeated once every second.

On the other hand, in the DETSUKA receiver, as shown in the block diagram of the conventional DETSUKA receiver in FIG. 14. The trigger receiving circuit 12 detects a trigger signal from the received signal and outputs it to the timing circuit 13. timing circuit 1
Reference numeral 3 generates a timing signal having the same timing as that of the pattern signals of the main station and the two slave stations, based on the detected trigger signal, and outputs it to the pattern receiving circuit 14. Pattern receiving circuit 14
selects and outputs M, Sl, and 32 signals from the input pattern signals M, St, and S2 under the control of the timing signal. These selected M, Sl, 32 signals are input to replacement oscillators 16, 17, 18, respectively. The replacement oscillator synchronizes the input M, Sl, and 52 signals, converts them to predetermined frequencies, and sends the signals Mfal, 5l(al, and S2(al) to one input terminal of the discriminators 19 and 20, respectively. Signal M
(Signal 5l(a) from al to the other input terminal)
and S 2 (input al. Discriminators 19 and 20 are input M, Sl and M, 52
The detected phase difference is output to the display sections 21 and 22, respectively. The display units 21 and 22 perform lane identification based on the input phase difference.

These two lanes identified by the display units 21 and 22 are compared with the hyperbola of the deck chart, and the position of the receiving point can be determined from the intersection of the curves.

In such a hyperbolic navigation system, as mentioned above, the transmission output signal is a pattern signal of each transmitting station that is transmitted once per second, and the period actually used for phase measurement is This is the Bakoon signal time width, which is 70% of one cycle.

For this reason, the pull-in range of the signals of the replacement oscillators 16 to 18 is as narrow as about 0.6l2, and a deviation of ±IH2 causes the same phenomenon as if synchronous pull-in was performed.

tel Purpose of the Invention The present invention was devised in view of a series of drawbacks of the conventional hyperbolic navigation system, and its purpose is to enable a Detsuka receiver to accurately receive Detsuka pattern signals output from a main and two slave transmitters. Another object of the present invention is to provide a hyperbolic navigation system that can widen the pull-in range of the pattern signal and improve phase measurement accuracy.

According to the present invention, the trigger signal and the main pattern signal are transmitted from the main transmitter, and the first and second slave pattern signals are transmitted from the first and second slave transmitters to predetermined values. A DETSUKA receiver receives DETSUKA pattern signals that are transmitted in series with intervals and a predetermined signal time width, and calculates the phase difference between the main pattern signal and the first and second sub pattern signals. In the hyperbolic navigation system in which the position of a receiving point is determined by detection, each transmitter is provided with an insertion means for inserting an additional transmission pattern signal having a short signal time width into the interval time period of each transmission pattern signal, and the receiver This is achieved by a hyperbolic navigation method characterized in that phase synchronization is performed for each transmission pattern signal including the additional transmission pattern signal on the side.

tel Embodiment of the Invention Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 4 shows a timing diagram of the deck pattern signal of the present invention, and FIGS. 5 and 6 show block diagrams of the main transmitter and receiver of an embodiment according to the invention.

As shown in FIG. 5, the main transmitter of the embodiment is shown in FIG.
A 90 degree phase conversion circuit 23 is added to the conventional main transmitter shown in the block diagram. The slave station transmitter is shown in Figure 2 (
The configuration is the same as the conventional slave transmitter configuration shown in the block diagram of bl.

That is, as shown in the block diagram of the main transmitter in FIG. 5, the trigger signal 1 generated by the trigger signal generator 1, the main station signal M generated by the pattern signal generator 2, and the pattern signal A trigger 2 signal obtained by converting the output signal of the generator 2 by 90 degrees in a 90 degree phase conversion circuit 23 is input to the switching circuit 5, respectively. The switching circuit 5 is controlled by the timing circuit 9 to switch the input trigger signal 1. The pattern signals M and ) are sequentially switched and outputted at the timing shown at 81 in FIG. This output signal is transmitted to the outside via the transmitting circuit 5 and the transmitting antenna 6.

Further, the transmitters of slave station 1 and slave station 2 transmit pattern signals B1 and B2 of slave station 1 and slave station 2 at timings shown in FIG. 4 82 and B3 under the control of their respective timing circuits 9. In other words, the trigger signal 2. uses the empty interval between each signal that existed in the conventional timing to shorten the transmission time to the empty interval. pattern signal M,
SL, 52 is inserted. In the timing diagram of FIG. 482 and B3, each pattern signal is transmitted twice and three times as many times per second as in the conventional case.

On the other hand, as shown in the block diagram of FIG. 6, the deck receiver of this embodiment has a 90 degree phase detection circuit 24 added to the timing circuit 13 of the conventional receiver block diagram shown in FIG.

That is, in FIG. 6, the 90 degree phase detection circuit 24 receives pattern signals M, Sl, S2 . ) Trigger 2 signal that has a phase difference of 90 degrees from other signals is detected from Trigger 2, and the timing circuit 13
Output to. The timing circuit 13 receives the input trigger 2.
The timing system of the received pattern signal, that is, the timing system 81 or the timing system 82 in FIG. . The pattern signal receiving circuit 14 is controlled by the timing signal output from the timing circuit 13, selects pattern signals M, Sl, and S2, and sends each pattern signal to a replacement oscillator 16.
．． Output on 17.18. Replacement oscillator 16.17.18
synchronizes the input pattern signals M, Sl, and S2, converts them to a predetermined frequency, and generates the signal M(al, 5
l(a) and 521al, and output to discriminators 19 and 20, respectively.

In this synchronization pull-in, the pattern signal is input two to three times as many times as before in one second.

Therefore, the number of synchronization pull-in increases from two to three times, and the synchronization pull-in range becomes correspondingly wider, and stable synchronization pull-in is performed.

Next, as described in the conventional example, the discriminators 19 and 20 detect the phase difference between the replacement signals M (al and S 1 (al and M (al and S 2 (al) and identify the lane based on the detected phase difference. You can find out the location of the receiving point by doing this.

(fl) Effects of the Invention As is clear from the above explanation, the present invention is capable of widening the synchronization range of the Detsuka receiver and achieving stable synchronization by increasing the number of times the Bakun signal is transmitted and received compared to the conventional one. This makes it possible to improve the accuracy of position measurement.

[Brief explanation of the drawing]

FIG. 1 is a timing diagram of a conventional DETSUKA pattern signal, FIG. 2 is a block diagram of a conventional main and slave transmitter, FIG. 3 is a block diagram of a conventional receiver, and FIG. 4 is a block diagram of a conventional receiver. FIGS. 5 and 6 show block diagrams of the main station transmitter and receiver of an embodiment according to the present invention. In the figure, ■ is a trigger signal generator, 2 is a pattern signal generation circuit, 3 is a switching circuit, and 4. 9.13 is a timing circuit, 5 is a transmitting circuit, 6 is a transmitting antenna, 7.11 is a receiving antenna, 8 is a trigger signal detection circuit, 12 is a trigger receiving circuit, 14 is a pattern signal receiving circuit, 16, 17.1
8 is a replacement oscillator, 19.20 is a discriminator, 2
Reference numeral 1.22 indicates a display section, and reference numeral 24 indicates a 90-degree phase detection circuit. Figure 1 Figure 2 (0) Figure 3 1 Figure 4

Claims (1)

[Claims] The trigger signal and main pattern signal are transmitted from the main transmitter, and the first and second slave pattern signals are transmitted from the first and second slave transmitters in series at predetermined intervals and with a predetermined signal time width, respectively. In the hyperbolic navigation method, the position of the receiving point is determined by receiving a Detsuka pattern signal with a Detsuka receiver and detecting a phase difference between the main pattern signal and the first and second sub-pattern signals, Each of the transmitters is provided with an insertion means for inserting an additional transmission pattern signal having a short signal time width into the interval time period of each transmission pattern signal, and the receiver side inserts each transmission pattern signal including the additional transmission pattern signal. A hyperbolic navigation system characterized by phase synchronization between each phase.