JPH065278B2 - Distance measuring device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distance measuring device, and more particularly to a distance measuring device that measures a distance to a target using a distance measuring tone signal.

[Conventional technology]

In the past, this type of distance measuring device has used an ambiguity removal tone having a wavelength that is an integral multiple of this signal, following the reference ranging tone signal, in order to remove ambiguity (phase uncertainty). Signals are sequentially transmitted, and the phase difference is measured individually between these signals and the returned signal, and the ambiguity-removed distance is calculated based on the combination of these measurement results, or for ambiguity removal. , PN (Pseudo Noise) superimposed on the ranging tone signal
The code signal is transmitted and the ambiguity removed distance is calculated by using the delay time of the received PN code signal.

[Problems to be solved by the invention]

In order to remove the ambiguity, the above-described conventional distance measuring device generates and transmits a tone signal having a wavelength that is an integral multiple of this signal, following a distance measuring tone signal that serves as a reference, and these signals. Since the phase difference with the received tone signal is measured for each tone signal, more tones are removed in order to remove ambiguity in order to measure with high accuracy and long distance. There is a drawback that a signal is required and the measurement time becomes long.

Further, when the PN code signal is used, the PN code period becomes longer as the measurement distance becomes longer, which makes it difficult to capture the returned PN code, and the circuit becomes complicated.

An object of the present invention is to provide a distance measuring device capable of measuring in a short time and with high accuracy and preventing the circuit from becoming complicated.

[Means for solving problems]

The distance measuring device of the present invention is a distance measurement tone signal generator for generating a distance measurement tone signal having a predetermined frequency according to a transmission control signal, and a PCM data communication signal including a frame synchronization pattern signal and PCM data according to the transmission control signal. And a PCM data signal sending section that outputs a transmission timing signal that is synchronized with the frame synchronization pattern signal, and a sending section that emits radio waves of the ranging tone signal and the PCM data communication signal to a target object. A reception unit that receives and processes return radio waves from the target object, a separation filter that separates a ranging tone signal and a PCM data communication signal from an output signal of the reception unit, and a PC that is received from the separation filter.
A PCM data demodulation unit that inputs an M data communication signal and outputs a reception timing signal that is synchronized with a frame synchronization pattern signal of this PCM data communication signal, and a clock signal that starts counting with the transmission timing signal and stops counting with the reception timing signal And a phase difference between the distance measurement tone signal from the distance measurement tone signal generator and the distance measurement tone signal received from the separation filter for a predetermined period by the reception timing signal. It has a phase difference measuring unit that measures and outputs a phase difference signal, and an arithmetic processing control unit that outputs the transmission control signal and calculates the distance from the time difference signal and the phase difference signal to the target object. ing.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

The distance measurement tone signal generation unit 1 outputs a distance measurement tone signal S _TT of a predetermined frequency according to the transmission control signal C _T from the arithmetic processing control unit 9.

The PCM data signal transmission unit 2 follows the transmission control signal C _T to generate a bit synchronization pattern signal B, a frame synchronization pattern signal F that follows it, and a PCM data signal D that follows this.
It outputs a PCM data communication signal S _PT including and a transmission timing signal T _T synchronized with the trailing edge of the frame synchronization pattern signal F.

The transmitter 3 emits radio waves of the ranging tone signal S _TT and the PCM data communication signal S _PT to the target 10.

The receiving unit 4 receives and processes the radio waves returned from the target object 10 and outputs them.

The separation filter 5 separates the output signal from the reception unit 4 into the ranging tone signal S _TR and the PCM data communication signal S _PR .

The PCM data demodulation unit 6 receives the received PCM data communication signal S _PR , outputs the reception timing signal T _R synchronized with the end edge of the frame synchronization pattern signal F of the PCM data communication signal S _PR , and outputs the PCM data. The signal D is output.

The time interval counter 7 starts counting the clock signal CK by the transmission timing signal T _T , stops this counting by the reception timing signal T _R , and the radio wave emitted from the transmitting unit 3 determined by this count number is the target 10 The time required to reach the receiving unit 4 through the time, that is, the time difference between the emitted radio wave and the received radio wave is output as a time difference signal.

The phase difference measuring unit 8 determines the position of the distance measurement tone signal S _TT from the distance measurement tone signal generator 1 and the distance measurement tone signal S _TR received from the separation filter 5 for a predetermined period PM according to the reception timing signal T _R. The phase difference is measured multiple times and averaged, and output as a phase difference signal.

The arithmetic processing control unit 9 outputs the transmission control signal C _T that determines the start of the distance measurement, while receiving the time difference signal from the time interval counter 7 and the phase difference signal from the phase difference measuring unit 8 and also outputting these signals. Then, a predetermined calculation is performed on and to calculate and output an accurate distance to the target.

FIG. 2 is a timing chart for explaining the operation of this embodiment.

The count period t of the clock signal CK of the time interval counter 7 from the rising of the transmission timing signal T _{T to} the rising of the reception timing signal T _R corresponds to the round trip distance to the target 10. Since the distance measurement tone signal having a relatively high frequency can be used by using the PCM data communication signal, an approximate distance is calculated by this count number, and the frequency of the clock signal CK and the distance measurement tone signal is calculated based on this count number. An accurate distance can be calculated by incorporating the relationship, the phase difference measurement result, and the like. The time interval between adjacent frame synchronization pattern signals F (repeating cycle)
Is usually longer than the time corresponding to the round trip distance to the target 10, so there is no ambiguity with respect to the frame synchronization pattern signal F in this case. Further, even when the repeating cycle of the frame synchronization pattern signal F becomes shorter, the respective frame synchronization pattern signals F can be distinguished by the contents of the PCM data signal D, and thus the ambiguity with respect to the frame synchronization pattern signal F is also the same. Absent.

〔The invention's effect〕

As described above, according to the present invention, the distance calculated by the round-trip time of the PCM data communication signal is added to the phase difference between the transmitting and receiving signals of the ranging tone signal synchronized with the PCM communication signal to calculate an accurate distance. By doing so, only one distance measurement tone signal with a relatively high frequency is required even if the distance becomes long, and a PN code with a long cycle is not required, so that the circuit is not complicated and distance measurement can be performed in a short time. And there is an effect that it can be performed with high accuracy.

Further, there is an effect that the distance measurement and the PCM data communication can be performed at the same time.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a timing chart for explaining the operation of the embodiment shown in FIG. 1 ... distance measurement tone signal generator, 2 ... PCM data signal transmitter, 3 ... transmitter, 4 ... receiver, 5 ... separation filter, 6 ...
PCM data demodulation unit, 7 ... time interval counter, 8 ... phase difference measuring unit, 9 ... arithmetic processing control unit, 10 ... target object.

Claims (1)

[Claims] 1. A distance measurement tone signal generator for generating a distance measurement tone signal of a predetermined frequency according to a transmission control signal, and a PCM data communication signal including a frame synchronization pattern signal and PCM data according to the transmission control signal. And a PCM data signal transmitting section for outputting a transmission timing signal synchronized with the frame synchronization pattern signal, a transmitting section for emitting radio waves of the ranging tone signal and the PCM data communication signal to a target, and the target. The receiving unit that receives and processes the return radio wave from the unit, the separation filter that separates the distance measurement tone signal and the PCM data communication signal from the output signal of the reception unit, and the PCM data communication signal received from the separation filter are input. PCM data demodulation for outputting a reception timing signal synchronized with the frame synchronization pattern signal of this PCM data communication signal A time interval counter that starts counting a clock signal by the transmission timing signal, stops counting by the reception timing signal, and outputs a time difference signal; and a measurement from the distance measurement tone signal generation unit for a predetermined period by the reception timing signal. A phase difference measuring unit that measures a phase difference between the distance tone signal and the distance measurement tone signal received from the separation filter and outputs a phase difference signal; and a time difference signal and the phase difference that output the transmission control signal. A distance measuring device, comprising: a calculation processing control unit that calculates a distance from a signal to the target object.