JPH03188389A - Distance measuring equipment - Google Patents

Abstract

PURPOSE:To enable measurement of a distance not affected by a change in temperature and others by counting a signal delay time from transmission to output of a reception element and by controlling the start of counting of a distance value on the basis of a count value thus obtained and a reference value. CONSTITUTION:A corrective detection counter 9 counts up reception of corrective detection counter start pulse 103 being synchronous with a query pulse 100 sent from a timing generator 7 to a transmission element 12, and counting of the corrective detection counter 9 is stopped by a query pulse 601 sent through a reception element 4 and a gate 6. The count of the corrective detection counter 9 at this time corresponds to a signal delay time of the transmission element 12 and the reception element 4. A difference detector 11 determines a difference between an output of the corrective detection counter 9 and a reference value of a reference value generating circuit 10. This value is added to a distance calculation start reference value in a distance calculation start pulse correction circuit 8 and a distance calculation start pulse 101 is outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a distance measuring device, and in particular to a distance measuring device.
-stance Measuring Equipme
The present invention relates to a distance measuring device that is used for applications such as nt) and measures distance by measuring the time from sending out an interrogation pulse to receiving a response pulse.

[Conventional technology]

The DME device is an aircraft navigation device that receives information between the aircraft and the ground DME station, and provides the aircraft with information on the distance to the ground DME station.

The distance measurement method of the DME device is that when an aircraft discretely transmits interrogation pulses for distance measurement to a ground DME station, the ground DME station receives the interrogation pulses and takes into account time delays in signal processing. It is operated using a secondary radar method that transmits a response pulse after a unique delay time set in advance.

[Problem to be solved by the invention]

The conventional DME distance measurement described above extracts a specific pulse synchronized with the interrogation pulse from among the received random pulses, and measures the period with the interrogation pulse.

Conventional DME devices basically measure the time from the sending of the interrogation pulse to the reception of the response pulse, but this includes the signal delay time of the transmitting section, receiving section, etc., so the delay time due to temperature changes etc. There is a drawback that errors in distance measurement values occur due to changes in temperature, that is, changes in temperature.

An object of the present invention is to eliminate the above-mentioned drawbacks and to provide a distance measuring device that is not affected by temperature changes by monitoring the signal delay time of the transmitting section and the receiving section.

[Means to solve the problem]

The distance measuring device of the present invention measures a distance by extracting a synchronization pulse as a response pulse synchronized with an interrogation pulse from among the response pulses sent back from a beacon after transmitting an interrogation pulse. a counting means for receiving the interrogation pulse and counting the time interval between the interrogation pulse and the interrogation pulse; and a counting means for extracting a part of the interrogation pulse and inputting it to a system reception section to count the signal delay time from the system transmission section to the output of the system reception section. A delay time counting means, a difference detection means for detecting a difference between a count value by the delay time counting means and a reference value, and a counting start control means for controlling the start of counting by the counting means based on the difference. configured.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of a distance measuring device according to the present invention, and together with an antenna 1, a transmitting/receiving switch 2, a receiving section 4 as a counting means, a counting circuit 5, and a transmitting section 12, a delay time counting means is formed. question pulse pickup circuit 3,
A gate 6 forming a counting start control means, a timing generator 7, a distance calculation start pulse correction circuit 8, a correction detection counter 9, a reference value generation circuit 10 as a difference detection means,
It includes a difference detection circuit 11 and a transmitter 12.

Next, the operation of the embodiment shown in FIG. 1 will be explained.

The interrogation pulse 100 from the timing generator 7 is sent to the transmitter 12, amplified, passed through the transmitter/receiver switch 2, and sent to the terrestrial DME station via the antenna 1. When the interrogation pulse is sent, the system delay time (
50 μs) and a signal delay time between the transmitter 12 and the receiver 14, the distance calculation start pulse correction circuit 8 outputs the distance calculation start pulse 101 to the counting circuit 5. The response pulse from the terrestrial DME station is input to the receiving section 4 via the antenna 1 and the transmitting/receiving switch 2.
The receiving section 4 amplifies and decodes the pulse, and outputs a response pulse 401 to the counting circuit 5. The counting circuit measures the time from the distance calculation start pulse 101 to the response pulse 401 to obtain a distance value.

A part of the interrogation pulse 301 from the transmitter 12 is extracted by the transmit signal pickup circuit 3, frequency-converted, and input to the receiver 4. This signal passes through the receiving section 4,
Its output is input to the gate 6 as an interrogation pulse 601. The timing generator 7 sends a gate pulse 102 that controls the gate 6 around the time when the interrogation pulse 601 appears at the output end of the receiver 4.
1 passes through the gate 6 and is sent to the correction detection counter 9. On the other hand, the correction detection counter 9 receives a correction detection counter start pulse 103 synchronized with the interrogation pulse 100 sent to the transmitter 12 from the timing generator 7 and counts up. The correction detection counter 9 stops counting by the sent interrogation pulse 601. The count value of the correction detection counter 9 at this time becomes a value corresponding to the signal delay time of the transmitter 12 and the receiver 4. The difference detector 11 calculates the difference +ΔT between the output of the correction detection counter 9 and the reference value of the reference value generation circuit 10, and adds this value to the distance calculation start reference value in the distance calculation start pulse correction circuit 8. The distance calculation start pulse correction circuit 8 receives the interrogation pulse 1 from the timing generation circuit 7.
After a reference time elapses from 00, a countdown pulse 104 is input, and when the count reaches 0, for example, a distance calculation start pulse 101 is output.

FIG. 2 is a timing chart showing correction of the distance calculation start pulse in the embodiment shown in FIG.

The correction detection pulse shown in (C) in Figure 2 is at a temperature of To'C.
The correction detection pulse shown in (d) is T. This includes the temperature fluctuation at T1°C, which is a temperature rise higher than °C. Also, (e) and (f) are To
This shows the distance calculation start pulse at C and T1℃.As is clear from this figure, the distance calculation start pulse is set to compensate for the variation in the delay time between the transmitting section and the receiving section due to temperature changes. This can be ensured with a pulse correction circuit.

〔Effect of the invention〕

As explained above, the present invention is not affected by temperature changes, etc. by counting the signal delay time from transmission to the output of the receiving section and controlling the start of distance value counting based on this counted value and a reference value. It has the effect of being able to measure distance.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the distance measuring device of the present invention, and FIG. 2 is a timing chart showing correction of the distance calculation start pulse in the embodiment of FIG. 1, together with related components. DESCRIPTION OF SYMBOLS 1... Antenna, 2... Transmission/reception switch, 3... Interrogation pulse pickup circuit, 4... Receiving section, 5... Counting circuit, 6... Gate, 7... Timing generator ,
8... Distance calculation start pulse correction circuit, 9... Correction detection counter, 10... Reference value generation circuit, 11...
- Difference detection circuit, 12... transmitter.

Claims (2)

[Claims] (1) In a distance measuring device that measures a distance by extracting a synchronization pulse as a response pulse synchronized with an interrogation pulse from among the response pulses sent back from a beacon after transmitting an interrogation pulse, the distance measuring device receives the response pulse and receives the interrogation pulse. a counting means for counting the time interval between pulses; and a delay time counting means for extracting a part of the interrogation pulse and inputting it into a system receiving section and counting the signal delay time from the system transmitting section to the output of the system receiving section. , comprising: difference detection means for detecting a difference between the count value by the delay time counting means and a reference value; and counting start control means for controlling the start of counting by the counting means based on the difference. Distance measuring device. (2) The signal delay time counted by the delay time counting means is a signal delay time that includes a change due to a temperature change in the system transmitter and the system receiver. (1) Distance measuring device described.