JPH09197036A - Distance measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a method for measuring the distance between two points exactly and economically for knowing the existence of a moving object by sending high frequency power modulated with a synchronizing signal from the measuring side as wave, converting the frequency of a high frequency signal received in the opposite side and sending it to the measuring side. SOLUTION: Synchronizing signal from a synchronizing signal generator 3 is modulated with a modulator 4 and sent to the air as high frequency wave signal by a transmitter 1 via a transmission antenna 2. This wave coming in a receiver 6 from a receiving antenna 5 on the opposite side is amplified, converted in frequency 7 and sent to the air from a transmitter 8 via a transmission antenna 9. This wave reaches the measurement side, comes in a receiver 11 via a receiver antenna 10 and a synchronizing signal is detected with a synchronizing signal detector 12 and output to a terminal 13. As the synchronizing signal generated in a generator 3 is output, the time difference of occurrence of both synchronizing signals is calculated and the distance between the two points can be calculated from the transmission delay time subtracted of a fixed delay time.

Description

Detailed Description of the Invention

[Industrial application] The present invention is mainly used to clarify the location of a moving body by measuring the distance from a few measuring points to the moving body.

2. Description of the Related Art Conventionally, it has been possible to measure a propagation delay time of a radio wave and measure a distance between two points by having a clock accurately calibrated at two points to be measured. It has been difficult to maintain a predetermined time accuracy on the moving body side, and it has not been generally performed. As a method of knowing the position of the moving body, radio waves modulated with a synchronization signal with accurate time accuracy are transmitted from three points, and the radio waves are received on the side of the moving body to measure the reception time difference between the three synchronization signals. Although it depends on the calculation, the measurement point is a moving body and does not satisfy the requirement of knowing the whereabouts of the moving body.

[Problem to be Solved by the Invention] The present invention mainly develops a method for accurately and economically measuring the distance between two points for the purpose of knowing the location of a moving body.

[Means for Solving the Problem] The distance measuring method of the present invention is composed of various means on the measuring side and various means on the opposite side. (Hereinafter, refer to FIG. 1) Radio wave transmission means on the measurement side are given by 1 and 2, and synchronization signal transmission means are given by 3 and 4. The sync signal is sent by sending high frequency power modulated by the sync signal as a radio wave, but the modulation method does not matter whether it is amplitude modulation, phase modulation, etc., and it is also possible to use the rising edge of the sent radio wave as the sync signal. is there. The receiving means of the radio wave from the measuring side on the opposite side is 5 and 6,
The means for converting the frequency of the received high frequency signal is given by 7, and the means for transmitting the converted radio wave is given by 8 and 9, respectively. As a means for converting the frequency, the super heterodyne method, the multiplication method or the frequency division method does not affect the functional operation, but the low frequency multiplication method and the frequency division method do not require a local oscillator, so they are simple and economical. Is.
Radio wave receiving means 10 and 11 on the measurement side and synchronization signal detecting means 12 are provided.

[Operation] (Refer to FIG. 1) The high-frequency signal sent from 1 becomes a radio wave through 2 and is sent to the space, and this radio wave is modulated by 4 with the synchronizing signal generated at 3. This radio wave reaches the opposite side, becomes a high frequency signal via 5, and is added to 6 to be selected, amplified, and added to 7. Then, the frequency is converted at 7, amplified at 8, and transmitted as radio waves through 9 to the space. This radio wave reaches the measurement side, becomes a high frequency signal via 10, and is added to 11 to be selected, amplified, and added to 12. Then, the synchronization signal is detected at 12 and output to 13. Since the sync signal generated in 3 is output to 14, the difference between the occurrence times of both sync signals is calculated and the fixed delay time by various means is subtracted from the two points of the measurement side and the opposite side. Propagation delay time, which enables calculation of the distance between two points. On the measurement side, if the location where the sync signal is generated and the location where the sync signal is detected are separated, etc., the intended function is to detect the sync signal by receiving the radio wave sent from the measurement side. Can be satisfied. Although it is possible to prepare three sets of distance measuring devices to know the whereabouts of the moving body, select three points that are not on a straight line apart from the measurement side points, and at each point, the measurement side and the opposite side. It is economical to receive and process each radio wave transmitted from. When it is desired to know the whereabouts of one moving body among many moving bodies, the target moving body is activated by selective calling.

[Embodiment] This method can be widely used for searching for a wandering elderly person or a stolen vehicle, searching for a car in a parking lot, and the like.

[Advantages of the Invention] According to this method, the distance between two points can be accurately and economically known. By combining this method, the location of the moving body can be provided without providing another transmission means. It is something you can know directly.

[Brief description of drawings]

FIG. 1 System diagram of the present invention

[Explanation of symbols]

 1: Transmitter 2: Transmitting antenna 3: Synchronous signal generator 4: Modulator 5: Receiving antenna 6: Receiver 7: Frequency converter 8: Transmitter 9: Transmitting antenna 10: Receiving antenna 11: Receiver 12: Synchronization Signal detector 13: Sync signal detection output terminal 14: Generation sync signal output terminal Dotted line arrow: Indicates the traveling direction of radio wave

Claims (3)

[Claims] 1. A means for transmitting a radio wave is provided on the measuring side. (2) A means for transmitting a synchronization signal is provided on the measurement side. (3) A means for receiving radio waves from the measurement side is provided on the opposite side. (4) A means for converting the frequency of the received radio wave is provided on the opposite side. (5) A means for transmitting radio waves of the converted frequency is provided on the opposite side. (6) The measuring side is provided with means for receiving radio waves from the opposite side. (7) A means for detecting the synchronization signal is provided on the measurement side. A distance measuring method configured by the above means. 2. The distance measuring method according to claim 1, wherein a received radio wave is multiplied as a frequency conversion method. 3. The distance measuring method according to claim 1, wherein the received radio wave is divided as a frequency conversion method.