JP3782409B2 - Moving object distance detection system - Google Patents

Description

  The present invention relates to a moving object distance detection system that detects a distance to a moving object to be measured.

Conventionally, a radio wave radar using microwaves or millimeter waves is generally known as a distance measuring device using radio waves (see, for example, Patent Document 1). Radio wave radars are classified into pulse radars, FMCW (Frequency Modulated Continuous Wave) radars, etc., depending on the system. Recently, spread spectrum radar, CDMA (Code Division Multiple Access) radar, and the like are also known.

  The pulse radar obtains the distance to the measurement object by measuring the time from when the pulse signal is transmitted until it is reflected back to the measurement object. In addition, spread spectrum radar and CDMA radar basically measure the distance based on the round-trip propagation time to the measurement object, like the pulse radar.

The FMCW radar transmits a continuous wave that has been swept in frequency, and obtains the distance to the measurement object from the frequency difference between the transmitted signal and the reflected signal. This method is characterized in that the moving speed of the measurement object can be measured simultaneously.
JP 2000-97962 A

  However, the radar has a problem that it is generally difficult to measure a short distance, and the minimum detection distance is several tens of meters or more. Another radar other than the above is a Doppler radar. This Doppler radar has a simple structure and can measure a measurement object at a short distance, but has a problem that it cannot measure a distance to a measurement object that is stopped.

  Furthermore, in the above conventional radar, when a plurality of radars are used at the same time in the vicinity, there is no means for the receiver to receive signals transmitted from other radars, and the measurement error increases significantly. It has a problem that it cannot be done.

  On the other hand, as one of the applications of the above radar, there is an in-vehicle radar that detects an obstacle and measures the distance between the obstacle and the vehicle in order to avoid an obstacle to the vehicle, particularly a collision with a pedestrian. It is being considered. This in-vehicle radar has a minimum detection distance of several tens of centimeters or less and needs to measure a distance from a measurement object that is relatively stopped, and a signal transmitted from the in-vehicle radar of another vehicle. It must be possible to measure distance without being affected by However, it is difficult for the conventional radar to satisfy these three conditions.

  The present invention has been made to solve the above-described problem, and can detect the distance to a moving body at a short distance without being affected by a transmission signal from another moving body distance detection system, and It is an object of the present invention to provide a moving body distance detection system capable of detecting a distance to a moving body that is stopped.

The invention according to claim 1 is a moving body distance detection system for detecting a distance to a moving body to be measured, the transmitting means for outputting an output signal having a variable frequency, and the output from the transmitting means. A transmission means for emitting an electromagnetic wave having the same frequency as the frequency of the output signal to a propagation medium existing between the mobile body, the transmission means and the mobile body, and the transmission means and the mobile body Detection means for detecting the amplitude of the standing wave formed in the propagation medium between the moving body and outputting a detection signal corresponding to the detected amplitude of the standing wave, and detection output by the detection means signal and the frequency information is input of an output signal output by said transmitting means, to form a detectable signal function indicating the value of the detection signal relative to the frequency of the output signal, the detection signal function Fourier transform Forming a transformation function, it calculates a period of the detection signal function from the conversion function, a distance calculation means for calculating a distance between the moving body and the moving body distance detection system from the period of the detection signal function calculated And determining means for determining whether or not the distance between the moving object distance detection system calculated by the distance calculating means and the moving object is within a predetermined distance set in advance. Yes.

According to this configuration, the moving object distance detection system that detects the distance to the moving object to be measured can change the frequency of the output signal output from the transmitting means, and the wavelength of the electromagnetic wave emitted from the transmitting means. Changes, the amplitude of the standing wave formed in the propagation medium between the transmission means and the moving body changes. For this reason, if the frequency of the output signal is changed, the value of the detection signal output by the detection means changes, so the distance calculation means forms the detection signal function from the frequency information of the output signal and the value of the detection signal , The detection signal function can be Fourier transformed to form a conversion function, and the period of the detection signal function can be calculated from the conversion function . The amplitude of the standing wave at the position where the detection means is provided periodically changes with respect to the frequency of the electromagnetic wave, that is, the frequency of the output signal output from the transmission means, and the period is the detection means of the moving object distance detection system. Is inversely proportional to the distance from the moving object. Therefore, since the period of the standing wave amplitude, that is, the period of the detection signal function is obtained, the distance from the moving object distance detection system to the moving object can be calculated from the period. Further, it is determined whether or not the calculated distance between the moving object distance detection system and the moving object is within a predetermined distance set in advance.

The invention according to claim 2 is a moving object distance detection system for detecting a distance to a moving object to be measured, the output means outputting an output signal whose frequency is variable, and output by the transmitting means. Transmitting means for emitting light having the same frequency as the frequency of the output signal to the propagation medium existing between the moving body and the light emitted from the transmitting means into two parts, Of the light beam to the propagation medium existing between the moving body, the reflecting means for reflecting the other light split by the spectroscopic means, and between the spectroscopic means and the moving body. The amplitude of the standing wave formed in the propagation medium is detected based on the emission intensity of the one light reflected by the moving body and the emission intensity of the other light reflected by the reflecting means. For standing wave amplitude Detection means for outputting a corresponding detection signal, detection signal output by the detection means and frequency information of the output signal output by the transmission means are input, and the value of the detection signal with respect to the frequency of the output signal is indicated. A detection signal function is formed, a Fourier transform is performed on the detection signal function to form a conversion function, a period of the detection signal function is calculated from the conversion function, and the moving body distance is calculated from the calculated period of the detection signal function A distance calculating means for calculating a distance between the detection system and the moving body; and a distance between the moving body distance detecting system and the moving body calculated by the distance calculating means is within a predetermined distance set in advance. And determining means for determining whether or not there is a feature.

According to this configuration, the mobile body distance detection system that detects the distance to the mobile body to be measured changes the light emission intensity change by changing the frequency of the light emission intensity change of the light output from the light emitting means. Since the wavelength changes, the amplitude of the standing wave detected by the detecting means changes. For this reason, if the frequency of the light emission intensity is changed, the value of the detection signal output by the detection means changes. Therefore, the distance calculation means detects the detection signal from the frequency information of the light emission intensity change and the value of the detection signal. A function is formed , the detection signal function is Fourier transformed to form a conversion function, and the period of the detection signal function can be calculated from the conversion function . The magnitude of the amplitude of the light intensity change obtained by adding the intensities of one of the light reflected by the moving body in the spectroscopic means and the other light reflected by the reflective means is determined by the spectroscopic means. The amplitude is the same as the amplitude of the standing wave that can be placed at a position separated by the distance between the spectroscopic means and the reflecting means up to the moving body. Therefore, if the distance between the spectroscopic means and the reflecting means is known, the distance from the position away from the spectroscopic means toward the moving body by a predetermined distance to the moving body can be detected. The amplitude of the standing wave at a position separated from the spectroscopic means by the same distance as the distance between the spectroscopic means and the reflecting means changes periodically with respect to the frequency of the light emission intensity change, and the period is a moving object distance detection system. Is inversely proportional to the distance from the spectroscopic means to the moving body. Therefore, since the period of the standing wave amplitude, that is, the period of the detection signal function is obtained, the distance from the moving object distance detection system to the moving object can be calculated from the period. Further, it is determined whether or not the calculated distance between the moving object distance detection system and the moving object is within a predetermined distance set in advance.

  According to a third aspect of the present invention, the distance calculation unit receives the detection signal output by the detection unit and the frequency information of the output signal output by the transmission unit, and the detection signal with respect to the frequency of the output signal. Forming a detection signal function indicating a value of at least two, detecting frequencies of at least two or more output signals at which the detection signal function is maximum or minimum, and selecting two of the two or more output signal frequencies, and The distance between the moving object distance detection system and the moving object is calculated from the number of frequencies of the output signal that is the maximum or the minimum between two selected frequencies.

  According to this configuration, the moving object distance detection system that detects the distance to the moving object to be measured can change the frequency of the output signal output from the transmitting means, and the wavelength of the electromagnetic wave emitted from the transmitting means. Changes, the amplitude of the standing wave formed in the propagation medium between the transmission means and the moving body changes. For this reason, if the frequency of the output signal is changed, the value of the detection signal output by the detection means changes, so that the detection signal function is formed by the distance calculation means from the frequency information of the output signal and the value of the detection signal. Can do. The amplitude of the standing wave at the position where the detecting means or the spectroscopic means is provided periodically changes with respect to the frequency of the electromagnetic wave, that is, the frequency of the output signal output from the transmitting means, and the period is the detecting means or spectroscopic means. Is inversely proportional to the distance from the moving object. Therefore, the frequency at which the amplitude of the standing wave is maximized or minimized, that is, two or more frequencies at which the detection signal function is minimized or maximized is detected, and two arbitrarily selected frequencies among these two or more frequencies are detected. Since the period of the detection signal function can be obtained by calculating the number of minimum or maximum frequencies formed between the selected frequencies, the detection means or the spectroscopic means of the moving object distance detection system can be obtained from the period. The distance to the moving body can be calculated.

  According to a fourth aspect of the present invention, the transmission means includes a modulation means for frequency modulating an output signal, and the detection means detects an amplitude of the standing wave and has an amplitude corresponding to the amplitude. A receiving means for outputting a detection signal and a modulation signal from the modulation means are input, the detection signal is synchronously detected by the modulation signal to form a detection signal, and a detection signal corresponding to the amplitude of the detection signal is output. And a detection means.

  According to this configuration, the detection signal output from the reception unit is synchronously detected to form a detection signal, and the detection unit outputs a detection signal corresponding to the amplitude of the detection signal. Then, the detection signal curve monotonously increases or decreases in the vicinity of the frequency at which the standing wave amplitude is minimized or maximized, and further, before and after the frequency at which the standing wave amplitude is minimized or maximized. It becomes a curve in which the sign of the value of the detection signal changes. Therefore, the frequency at which the amplitude of the standing wave is minimized or maximized can be accurately detected, and the measurement error can be reduced.

  According to a fifth aspect of the present invention, the moving body includes a human in a road facility, and the detecting means corresponds to an amplitude of a standing wave formed in the propagation medium between the transmitting means and the human. The distance calculation means calculates the distance between the moving object distance detection system and the person based on the detection signal output by the detection means.

  According to this configuration, the detection means outputs a detection signal corresponding to the amplitude of the standing wave formed in the propagation medium between the transmission means and the human, and is detected by the detection means by the distance calculation means. The frequency information of the output signal output by the detection signal and the transmission means is input, and a detection signal function indicating the value of the detection signal with respect to the frequency of the output signal is formed. Calculated. Therefore, when the moving body distance detection system is provided in a road facility, it is possible to detect the presence of a pedestrian (human) passing through the road facility, from the detection means or the spectral means of the moving body distance detection system to the human being. Can be detected, the detection range can be arbitrarily set.

  According to a sixth aspect of the present invention, the moving body includes a vehicle in a road facility, and the detecting means detects corresponding to a standing wave formed in the propagation medium between the transmitting means and the vehicle. The distance calculation means outputs a signal, and calculates the distance between the mobile body distance detection system and the vehicle based on the detection signal output by the detection means.

  According to this configuration, the detection means outputs the detection signal corresponding to the amplitude of the standing wave formed in the propagation medium between the transmission means and the vehicle, and the distance calculation means outputs the detection signal. The detection signal and the frequency information of the output signal output by the transmission means are input, a detection signal function indicating the value of the detection signal with respect to the frequency of the output signal is formed, and the distance between the detection means or the spectroscopic means and the vehicle is determined from the cycle. Calculated. Therefore, when the mobile body distance detection system is provided in the road facility, it is possible to detect the presence of the vehicle traveling on the road facility, and it is possible to detect the distance from the mobile body distance detection system to the vehicle. The detection range can be set arbitrarily.

  According to a seventh aspect of the present invention, when the determination unit determines that the distance between the moving object distance detection system and the moving object is within the predetermined distance, the rear collision with the moving object is performed. An alarm means for issuing a rear-end collision prevention alarm for preventing the accident is further provided.

  According to this configuration, when the moving body distance detection system is provided in the own vehicle and the moving body is a vehicle traveling in front of the own vehicle, the transmission is performed by the detection unit of the moving body distance detection system provided in the own vehicle. A detection signal corresponding to the amplitude of the standing wave formed in the propagation medium between the vehicle and the forward vehicle traveling in front of the mobile body is detected, and the detection device is based on the detection signal output by the detection device Alternatively, the distance between the spectroscopic means and the preceding vehicle, that is, the distance between the host vehicle and the preceding vehicle is calculated. It is determined whether or not the distance between the detection means or the spectroscopic means of the moving object distance detection system and the preceding vehicle is within a predetermined distance, and the distance between the detection means or the spectroscopic means and the preceding vehicle is determined. When it is determined that the vehicle is within a predetermined distance, a rear-end collision warning is issued to prevent a rear-end collision. The rear-end collision warning can be used to prevent a rear-end collision with a moving body.

  The invention according to claim 8 is an illumination lighting unit for lighting an illumination when the determination unit determines that the distance between the moving body distance detection system and the moving body is within the predetermined distance. Is further provided.

  According to this configuration, when the distance between the detection unit or the spectroscopic unit of the moving object distance detection system calculated by the distance calculation unit and the moving object is within a predetermined distance set in advance, the illumination is turned on. That is, when the moving body is a person in a road facility, a standing wave is formed by passing the moving body. Then, the distance to the person is detected based on the detection signal corresponding to the amplitude of the formed standing wave, and the street lighting that has been turned off is turned on based on the detected distance to the person. Therefore, normally, the illumination that is turned off is turned on when a standing wave is detected, so that power saving of the illumination can be realized.

  According to the ninth aspect of the present invention, when the determination unit determines that the distance between the moving object distance detection system and the moving object is within the predetermined distance, information on the periphery of the moving object is obtained. An information notification device for notification is further provided.

  According to this configuration, when the distance between the detection unit or the spectroscopic unit of the mobile body distance detection system calculated by the distance calculation unit and the mobile body is within a predetermined distance set in advance, the information notification apparatus causes the mobile body to Information on the surrounding area is notified. Here, the information around the moving object is, for example, information that prompts the caution of freezing the road in cold weather, information that prompts the pedestrian to jump out of the road with poor visibility, and the presence of a curve in a curve that frequently causes accidents. Information to be notified. The information notifying device is a notifying device using a light-emitting body installed on the side edge of the road, and notifies information on the surroundings of the moving body such as a caution for freezing, a warning for jumping out, and a warning about the curve ahead by text display or voice. That is, when the moving body is a person in a road facility, a standing wave is formed by passing the moving body. Then, the distance to the person is detected based on the detection signal corresponding to the amplitude of the formed standing wave, and the information notification device that has been turned off is turned on based on the detected distance to the person. Therefore, normally, since the information notification device that is turned off is turned on when a standing wave is detected, power saving of the information notification device can be realized.

  In a tenth aspect of the present invention, when the determination unit determines that the distance between the moving object distance detection system and the moving object is within the predetermined distance, the moving object is guided by light emission. The light emitting device further includes a light emitting device.

According to this configuration, when the distance between the detection unit or the spectroscopic unit of the mobile object distance detection system calculated by the distance calculation unit and the mobile object is within a predetermined distance, the mobile object is detected by the light emitting device. Be guided. Here, a plurality of light emitting devices are installed continuously on the side edge of the road, the light emitter is embedded in the case according to the road surface alignment, and the light emitting plate with the light emitter attached in the shape of an arrow is road. It attaches to the support | pillar standingly arranged by the side edge. That is, when the moving body is a vehicle in a road facility and the light-emitting device is embedded in the case with a plurality of light-emitting bodies built in the case according to the road surface alignment, first, the vehicle as the moving body passes through. A standing wave is formed. Then, the distance to the vehicle is detected based on the detection signal corresponding to the amplitude of the formed standing wave, and the plurality of light emitting devices that have been turned off are turned on based on the detected distance to the vehicle. Therefore, normally, the light-emitting device that is turned off is turned on when a standing wave is detected, so that power saving of the light-emitting device can be realized. Further, since the plurality continuously luminous body according to a linear road surface is provided, it is possible to recognize the linear road to the driver by inducing a driver's line of sight according to the linear road, the reflection Compared to the case of using body or line material, it has better visibility and is particularly effective in bad weather.

  According to an eleventh aspect of the present invention, the moving body includes a water surface of a river, and the detection means has an amplitude corresponding to a standing wave formed in the propagation medium between the transmission means and the water surface. A detection signal is output, and the distance calculation means calculates the distance between the moving body distance detection system and the water surface based on the detection signal detected by the detection means.

  According to this configuration, the detection signal corresponding to the amplitude of the standing wave formed in the propagation medium between the transmission means and the water surface is output, and the detection of the moving body distance detection system is performed based on the output detection signal. The distance between the means or the spectroscopic means and the water surface is calculated. Therefore, the water level of the river can be measured by detecting the distance between the detection means or the spectroscopic means of the mobile body distance detection system and the water surface of the river that is the mobile body. Can be used as

  The invention according to claim 12 is characterized by further comprising power storage means for storing the power generated by the solar cell, and using the power stored by the power storage means as a power source.

  According to this configuration, the power generated by the solar cell is stored by the power storage means, and the stored power is used as a power source, so that no other power source such as a commercial power source is required, and any power source such as a mountain or a remote place can be used. The moving body distance detection system can be operated at a place.

  According to the moving body distance detection system of the present invention, an electromagnetic wave having a predetermined frequency is emitted from a transmitting unit to a propagation medium existing between the moving body and the emitted traveling wave and a reflected wave reflected by the moving body. A standing wave is formed in the propagation medium due to the interference with the detection medium, the standing wave is detected by the detecting means, and the distance from the moving body distance detection system to the moving body is calculated based on the detected standing wave. The distance to the moving body can be detected according to various uses.

  The distance from the moving object distance detection system to the moving object depends on the fluctuation cycle of the amplitude of the standing wave with respect to the frequency of the output signal. Since it is not affected by the time to return to the detection system, even if the distance to the moving body is a short distance of, for example, several tens of centimeters or less, the distance to the moving body can be accurately detected.

  Embodiments according to the present invention will be described below with reference to the drawings. In addition, about the same structure in each figure, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  First, the moving body distance detection system according to the first embodiment of the present invention will be described. In the moving body position detection system according to the first embodiment, the distance between the distance detection device and the person in the road facility is detected, and lighting provided in the road facility is turned on based on the detected distance.

  FIG. 1 is a block diagram schematically showing the configuration of the moving object distance detection system in the first embodiment of the present invention.

  The moving body distance detection system 100a in the first embodiment includes a distance detection device 10, a power storage unit 200, a solar cell 300, a determination unit 400, a lighting control unit 410, and an illumination lamp 420.

  The distance detection device 10 detects the distance to the person M in the road facility as a moving body using the standing wave S, and outputs the detected distance to the person M to the determination unit 400. The distance detection device 10 will be described later with reference to FIGS.

  The power storage unit 200 is composed of, for example, a battery and is charged by the solar battery 300. The electric power accumulated in the power storage unit 200 by the solar battery 300 is supplied to the distance detection device 10 and the like.

  In this way, since the electric power generated by the solar cell 300 is accumulated by the power storage unit 200 for use as a power source of the moving object distance detection system 100a, other power sources such as a commercial power source are not necessary, The moving body distance detection system 100a can be operated in any place such as a remote place.

  The determination unit 400 determines whether the distance to the person M output from the distance detection device 10 is within a predetermined distance set in advance, and the distance to the person M is within the predetermined distance. If determined, a lighting signal for lighting the illumination lamp 420 is output to the lighting control unit 410.

  The lighting control unit 410 receives the lighting signal output from the determination unit 400 and controls the lighting lamp 420 to be turned on. The illuminating lamp 420 is, for example, street lighting provided in a road facility, and illuminates the course of a pedestrian (person M) passing through the road facility.

  Thus, when the moving body distance detection system 100a is provided in a road facility, the presence of a pedestrian (person M) passing through the road facility can be detected, and the distance from the distance detection device 10 to the person M can be detected. That is, since the distance from the moving object distance detection system 100a to the person M can be detected, the detection range can be arbitrarily set.

  Further, when the distance between the distance detection device 10 and the human being M is within a predetermined distance set in advance, the illumination lamp 420 is turned on. That is, the standing wave is detected by passing the human M, which is a moving body, and the illuminating lamp 420 that has been turned off is turned on. Therefore, normally, the illuminating lamp 420 that is turned off is turned on when a standing wave is detected, so that power saving of the illuminating lamp 420 can be realized.

  In the present embodiment, the moving body has been described as the human M passing through the road facility. However, the present invention is not particularly limited thereto, and the moving body may be a vehicle traveling on the road facility. In this case, when the moving body distance detection system 100a is provided in a road facility, the presence of a vehicle traveling on the road facility can be detected, and the distance from the moving body distance detection system 100a to the vehicle can be detected. Therefore, the detection range can be set arbitrarily. In addition, the distance detection device 10 can detect that the vehicle travels on the road facility and illuminate the course of the vehicle with the illumination lamp 420.

  Further, in the present embodiment, the illumination lamp 420 is described as street lighting provided in a road facility, but the present invention is not particularly limited to this. For example, bridge lighting, a lit road sign, and a road surface of a road A illuminable light emitter or the like embedded in the lamp may be used. In this case, visibility at night can be improved and traffic accidents can be prevented.

  In the present embodiment, the illumination lamp 420 that illuminates the road facility has been described. However, the present invention is not particularly limited to this, and an information notification apparatus that notifies information about the moving object instead of the illumination lamp 420 is provided. May be used. Here, the information around the moving object is, for example, information that prompts the caution of freezing the road in cold weather, information that prompts the pedestrian to jump out of the road with poor visibility, and the presence of a curve in a curve that frequently causes accidents. Information to be notified. The information notification device is composed of a light emitter and the like, and is installed on the side edge of the road. In other words, when the information notification device notifies the user of information that calls attention to freezing of the road in cold weather, the information “notice of freezing” is displayed by lighting the light emitter. Further, when the information notification device notifies the information that prompts the pedestrian to pay attention to the sight where the sight is poor, the information notification device displays the characters “caution to jump out” by lighting the light emitter. Furthermore, when the information notification apparatus notifies the existence of a curve in a curve or the like where accidents frequently occur, the information notification device displays the letters “this curve attention” by lighting the light emitter. That is, when the moving body is a person in a road facility, a standing wave is formed by passing the moving body. Then, the distance to the person is detected based on the detection signal corresponding to the amplitude of the formed standing wave, and the information notification device that has been turned off is turned on based on the detected distance to the person. Therefore, normally, since the information notification device that is turned off is turned on when a standing wave is detected, power saving of the information notification device can be realized. When the moving body is a human, the information notification apparatus may be configured with a speaker or the like that can output sound, and may notify information about the moving body by sound.

  Further, in this embodiment, instead of the illumination lamp 420, a light-emitting device that guides the moving body by light emission may be used. Here, a plurality of light emitting devices are installed continuously on the side edge of the road, the light emitter is embedded in the case according to the road surface alignment, and the light emitting plate with the light emitter attached in the shape of an arrow is road. It attaches to the support | pillar standingly arranged by the side edge. That is, when the moving body is a vehicle in a road facility and the light-emitting device is embedded in the case with a plurality of light-emitting bodies built in the case according to the road surface alignment, first, the vehicle as the moving body passes through. A standing wave is formed. Then, the distance to the vehicle is detected based on the detection signal corresponding to the amplitude of the formed standing wave, and the plurality of light emitting devices that have been turned off are turned on based on the detected distance to the vehicle. Therefore, the light emitting device that is normally turned off is turned on when a standing wave is detected through the vehicle, so that power saving of the light emitting device can be realized. In addition, since a plurality of light emitters are continuously provided according to the road surface alignment, the driver can recognize the road alignment by guiding the driver's line of sight to the road alignment and reflecting. Compared to the case of using body or line material, it has better visibility and is particularly effective in bad weather.

  In addition, for example, by providing the moving body distance detection system 100a in a road facility with poor visibility such as an intersection, an L-shaped road, a T-shaped road, and a highway junction, a vehicle traveling on one road is detected, The display board etc. which were provided in the other road may be light-emitted, and it may alert | report that the vehicle is approaching from one road with respect to the vehicle which drive | works the other road. In this case, the driver of the vehicle traveling on one road can know the presence of the vehicle traveling on the other road, and can effectively prevent a traffic accident.

  Next, the distance detection device 10 in the moving object distance detection system 100a will be described in detail.

  FIG. 2 is a block diagram schematically showing the configuration of the first example of the distance detecting device 10 in the moving object distance detecting system of FIG.

  The distance detection apparatus 10a in the first example includes a transmission unit 11a, a transmission unit 12a, a detection unit 13a, and a distance calculation unit 14a. In the present invention, the distance to the moving body M is detected using the standing wave S formed between the transmitter 12a and the moving body M.

  Here, the standing wave S will be described before describing the distance detector 10a of the first example.

  FIG. 3 is a schematic explanatory diagram for explaining the formation of the standing wave S. As shown in FIG. 3A, when an electromagnetic wave having a frequency f is emitted from the electromagnetic wave generator B1 into a propagation medium such as air, the electromagnetic wave travels in the propagation medium as a traveling wave D. In this traveling wave D, the amplitude VD at the position x from the electromagnetic wave generator B1 is expressed by the following equation (1) as a function of the frequency f and the distance x.

  VD (f, x) = exp (j2πf / c · x) (1)

  In the above formula (1), c represents the speed of light.

  Eventually, when traveling wave D reaches mobile body M, traveling wave D is reflected by mobile body M to become reflected wave R, and this reflected wave R travels from mobile body M toward electromagnetic wave generator B1. In this reflected wave R, the amplitude VR at the position of the distance x from the electromagnetic wave generator B1 is expressed by the following equation (2) as a function of the frequency f of the traveling wave D and the distance x from the electromagnetic wave generator B1.

  VR (f, x) = MR · exp (j2πf / c · (2d−x)) (2)

  MR in the above equation (2) represents the reflection coefficient of the electromagnetic wave in the moving body M, and is represented by MR = γ · exp (jφ).

3B, when the traveling wave D and the reflected wave R interfere with each other, a standing wave S is formed between the electromagnetic wave generator B1 and the moving body M. The amplitude SP of the standing wave S, as measured by the electromagnetic wave generator B1 a distance x ₁ as close to the mobile M detector B2, amplitude SP of the standing wave S which detector B2 is detected, the traveling wave D The frequency f is expressed by the following equation (3).

SP (f, x ₁ ) = (1 + γ ² + 2γcos (2πf / c · 2d ₁ + φ)) ^1/2 ... (3)

In the above equation (3), d ₁ = d−x ₁ is satisfied.

Thus, the amplitude SP of the standing wave S at the position where the detector B2 is provided is periodic with respect to the frequency f of the traveling wave D generated from the electromagnetic wave generator B1, and the period is c / 2d ₁ . That is, the amplitude SP of the standing wave S is inversely proportional to the distance d ₁ from the detector B2 to the moving body M. Therefore, if the frequency f of the traveling wave D is changed, the fluctuation period of the amplitude SP of the standing wave S with respect to the frequency f of the traveling wave D can be obtained at the position where the detector B2 is provided. The distance to the moving body M can be measured by the wave S.

  Returning to FIG. 2, the distance detection apparatus 10a in the first example will be described.

  The transmitter 11 a outputs a signal having a constant frequency f such as an AC power source, and includes a frequency transmitter 111 and a frequency controller 112. The frequency control unit 112 controls the frequency f of the signal output from the frequency transmission unit 111. Further, the frequency control unit 112 has information on the frequency f transmitted by the frequency transmission unit 111, for example, the numerical value of the frequency f of the signal transmitted by the frequency transmission unit 111 and the same frequency f as the signal transmitted by the frequency transmission unit 111. Output a signal.

  The transmission part 12a is comprised, for example with an antenna, an amplifier, etc., and is connected with the frequency transmission part 111 of the transmission part 11a. The transmission unit 12a has the same frequency f as the signal transmitted by the frequency transmission unit 111 of the transmission unit 11a in a propagation medium such as air or water or in a vacuum existing between the transmission unit 12a and the moving body M. The electromagnetic wave which has is emitted.

  For this reason, if the frequency f of the signal transmitted by the frequency transmitter 111 is changed by the frequency controller 112 of the transmitter 11a, the frequency of the electromagnetic wave emitted from the transmitter 12a can be changed.

Between the transmission unit 12a and the moving body M, a detection unit 13a such as an antenna, an amplitude detector, and a square detector is provided. The detection unit 13a determines the amplitude SP of the standing wave S formed by interference between the electromagnetic wave emitted from the transmission unit 12a (hereinafter referred to as traveling wave D) and the reflected wave R reflected by the moving body M. This is for detection, and is provided at a distance d ₁ from the moving body M. The detection unit 13a can output a detection signal corresponding to the amplitude SP of the standing wave S, for example, a current or voltage that is the same as the amplitude SP of the standing wave S or proportional to the square of the amplitude SP.

A distance calculation unit 14a is connected to the detection unit 13a. The distance calculation unit 14a includes, for example, a digital signal processor (DSP), a memory, and the like, and includes a recording unit (not shown) that records input data, and a calculation unit (not shown) that calculates data recorded in the recording unit. The distance d ₁ from the detection unit 13a to the moving body M can be calculated by the calculation unit.

  The distance calculation unit 14a is also connected to the frequency control unit 112 of the transmission unit 11a, and information about the frequency f of the output signal transmitted from the frequency transmission unit 111 from the frequency control unit 112 of the transmission unit 11a (hereinafter referred to as output). When the detection signal is received from the detection unit 13a, a reception confirmation signal is sent to the frequency control unit 112 of the transmission unit 11a.

  In addition, in the distance detection apparatus 10a in the first example, the transmission unit 12a and the detection unit 13a are provided separately. However, for example, the transmission unit 12a and the detection unit 13a may be combined with one antenna. In this case, the apparatus can have a compact and simple structure.

FIG. 4 is a flowchart illustrating an operation for measuring the distance to the moving body M by the distance detection device 10a. FIG. 5 is a waveform diagram for explaining the operation of the distance detection device 10a in the first example of the moving object distance detection system of FIG. 1, and FIG. 5 (A) shows the detection signal function A (f, d ₁₎ is a diagram showing, and FIG. 5 (B) and FIG 5 (C) is a diagram showing a detection signal function a (f, conversion function F Fourier transform of _{d 1)} (cy).

In step S1, the frequency control unit 112 of the transmitting portion 11a sets the initial frequency _{f L} and a final frequency _{f U} of the signal frequency transmission unit 111 transmits. In step S2, the frequency control unit 112, the frequency f transmitted from the frequency transmitter unit 111 outputs a signal which is an initial frequency _{f L} to the transmission unit 12a.

In step S3, the transmission unit 12a, the traveling wave D frequency f is the initial frequency f _L, toward the moving body M, and released into the propagation medium. At this time, the frequency information of the output signal is transmitted from the frequency control unit 112 to the distance calculation unit 14a. The traveling wave D emitted from the transmission unit 12a propagates through the propagation medium, reaches the moving body M, is reflected by the moving body M, becomes a reflected wave R, and is opposite to the traveling wave D, that is, the transmission unit 12a. It propagates in the propagation medium toward. Then, the traveling wave D and the reflected wave R interfere with each other, and a standing wave S is formed in the propagation medium between the transmission unit 12a and the moving body M.

  In step S4, the detection unit 13a detects the amplitude SP of the standing wave S formed in the propagation medium between the transmission unit 12a and the moving body M, and detects the detection signal corresponding to the amplitude SP of the standing wave S. Is transmitted to the distance calculation unit 14a.

  In step S5, the distance calculation unit 14a records the value P of the detection signal from the detection unit 13a on the recording unit in a one-to-one correspondence with the frequency information of the output signal transmitted from the frequency control unit 112. At the same time, the distance calculation unit 14 a transmits a reception confirmation signal to the frequency control unit 112.

In step S6, the frequency control unit 112 that has received the reception confirmation signal from the distance calculation unit 14a, the frequency f of the signal frequency transmission unit 111 transmits to determine whether to match the final frequency f _U. Here, the frequency f is determined not to match the final frequency f _U (NO at step S6), and the process proceeds to step S7, it is determined that the frequency f coincides with the final frequency f _U (YES in step S6 ), The process proceeds to step S8.

In step S7, the frequency control unit 112 changes the frequency f of the signal transmitted by the frequency transmission unit 111 by the step frequency Δf. Then, the frequency f of the traveling wave D emitted from the transmission unit 12a changes to f _L + Δf. However, since the traveling wave D propagates at a constant speed (light speed), the wavelength of the traveling wave D changes. . Therefore, the standing wave S formed in the propagation medium between the transmission unit 12a and the moving body M changes, and the amplitude SP of the standing wave S detected by the detection unit 13a changes. The value P of the detection signal sent to the distance calculation unit 14a changes.

In step S8, the distance calculation unit 14a forms a detection signal function A (f, d ₁ ) from the frequency information of the output signal recorded in the recording unit and the value P of the detection signal.

In step S9, the distance calculation unit 14a forms a conversion function F (cy) by performing a Fourier transform on the detection signal function A (f, d ₁ ). In step S10, the distance calculation unit 14a calculates a cycle cy at which the conversion function F (cy) peaks. As shown in FIG. 5B, the conversion function F (cy) is a function having a peak at the position of the period cy of the detection signal function A (f, d ₁ ), and is thus detected from the conversion function F (cy). The period cy of the signal function A (f, d ₁ ) can be calculated.

In step S11, the distance calculation unit 14a calculates the distance _{d 1} from the detection unit 12a to the mobile M. Since the cycle cy of the detection signal function A (f, d ₁ ), that is, the cycle of the standing wave S is inversely proportional to the distance d ₁ from the detection unit 13a to the moving body M, the mobile unit moves from the detection unit 12a to the moving body from the cycle cy. A distance d ₁ to M can be calculated.

In this way, the distance detection device 10a can detect the distance d ₁ from the detection unit 13a to the moving body M, that is, the distance from the moving body distance detection system to the moving body.

Further, the distance d ₁ from the detection unit 13a to the moving body M depends only on the period of the amplitude SP of the standing wave S with respect to the frequency f of the output signal, and the moving body after the traveling wave D is transmitted by the transmission unit 12a. since not affected by the time to return to the detector 13a is reflected to M, even if the distance d ₁ to the moving object M is a less short range several tens centimeters to measure accurately the distance it can.

Further, when a plurality of standing waves S are formed between the plurality of moving bodies M, the detection signal output from the detection unit 13a corresponds to a value obtained by combining the amplitudes SP of the plurality of standing waves S. It will be a thing. Then, the detection signal function A (f, d ₁ ) formed by the calculation unit of the distance calculation unit 14a is a synthesis function obtained by synthesizing a function indicating the variation of the amplitude SP of the plurality of standing waves S at the position of the detection unit 13a. However, the conversion function F (cy) formed by Fourier-transforming the detection signal function A (f, d ₁ ) is a function having a local maximum value in each period of the standing wave S. That is, as shown in FIG. 5C, when three standing waves S are formed, the conversion function F (cy) formed by Fourier transforming the detection signal function A (f, d ₁ ) is Are functions having peaks at the positions of the periods cy1, cy2, cy3, respectively.

Therefore, since the variation period of the amplitude SP of a plurality of standing waves S can be obtained, respectively, the distance d ₁ between the detecting portion 13a and a plurality of mobile M, it can be measured.

Further, instead of linearly changing the frequency f of the output signal frequency oscillator 111 of the transmission unit 11a is output from the initial frequency f _L for each final frequency f _U to step frequency Delta] f, initial frequency f _L and a final frequency f The amplitude f of the standing wave S at each frequency f may be measured by randomly changing the frequency f of the output signal between _U. In this case, since the frequency f of the output signal can correspond to the amplitude SP of the standing wave S, the detection signal function A (f, d ₁ ) can be formed by the calculation unit of the distance calculation unit 14a. For example, if the frequency f of the output signal is randomly changed according to the M-sequence code or the like, there is almost no probability that the distance detection devices 10a transmit electromagnetic waves having the same phase and the same frequency f at the same timing.

  Since the amplitude SP of the standing wave S is generated by components of the same frequency, even if the detection unit 13a receives an electromagnetic wave emitted by another distance detection device 10a, the signal component passes through the low frequency band. It can be easily removed by a filter or the like. Therefore, it is possible to prevent the measurement error from being remarkably increased or impossible to be measured due to the electromagnetic wave emitted from the other distance detection device 10a.

Further, instead of obtaining the period of the detection signal function A (f, d ₁ ) by the calculation unit of the distance calculation unit 14a, the frequency f of the output signal at which the detection signal function A (f, d ₁ ) becomes maximum or minimum is obtained. Two or more may be obtained, and the distance x between the moving body M and the transmission unit 12a may be obtained from those frequencies f.

  FIG. 6 is a diagram illustrating a flowchart of an operation of obtaining two or more frequencies of the output signal at which the detection signal function is minimized and measuring the distance between the moving body M and the transmission unit 12a from these frequencies. The processing from step S101 to S108 in the flowchart shown in FIG. 6 is the same as the processing from step S1 to S8 in the flowchart shown in FIG. .

In step S109, the distance calculation unit 14a detects two or more frequencies f _{n to} f _{n + k at} which the detection signal function A (f, d ₁ ) is minimized. As shown in FIG. 5A, since the detection signal function A (f, d ₁ ) is a periodic function, there are a portion where the value P of the detection signal is maximum and a portion where the value P of the detection signal is minimum. Appear alternately. Therefore, two or more frequencies f _{n to} f _{n + k at} which the value P of the detection signal is minimized are detected.

In step S110, the distance calculation unit 14a selects two frequencies as the selection frequencies f _n and f _{n + k} among the two or more frequencies f _{n to} f _{n + k} detected in step S109. Then, the number k−1 of minimum frequencies formed between the two selection frequencies f _n and f _{n + k} is calculated. Then, the distance d ₁ between the mobile M and the detection unit 13a is determined by the following equation (4).

d ₁ = k · c / (4 · (f _{n + k} −f _n )) (4)
That is, the two selected frequency _{f n,} and _{f n + k,} the two selected frequencies _{f n,} by calculating the number k-1 of the frequency becomes minimum formed between _{f n + k,} the movement from the detecting portion 13a The distance to the body M can be measured.

  In the first example, two or more frequencies of the output signal at which the detection signal function is minimized are obtained, and the distance between the moving body M and the transmission unit 12a is measured from these frequencies. However, the present invention is not particularly limited thereto, and two or more frequencies of the output signal at which the detection signal function is maximized may be obtained, and the distance between the moving body M and the transmission unit 12a may be measured from these frequencies.

FIG. 7 is a block diagram schematically showing the configuration of the distance detection device 10b in the second example of the moving object distance detection system of FIG. The distance detection device 10b in the second example includes a modulator 20 in addition to the transmission unit 11b, the transmission unit 12b, the detection unit 13b, and the distance calculation unit 14b, and the distance calculation unit 14b detects the detection signal function A (f, d _The feature is that the accuracy of detecting the frequency f of the output signal of the frequency transmission unit 111 that is the minimum of ₁ ) is increased.

  As shown in FIG. 7, in the transmission unit 11b, a modulator 20 is provided between the frequency transmission unit 111 and the frequency control unit 112. The modulator 20 is configured to output a signal that periodically varies with the frequency f as a center frequency from the frequency transmitter 111 when the frequency f to be output from the frequency transmitter 111 is set by the frequency controller 112. It is. That is, the modulator 20 is for applying frequency modulation to the output signal of the frequency transmitter 111.

  Further, the modulator 20 can output a modulation signal to the detection unit 13b. The modulation signal is a signal of a fluctuation component that periodically fluctuates with respect to the frequency f set by the frequency control unit 112 in the frequency-modulated output signal of the frequency transmission unit 11a.

  Furthermore, the detection unit 13b includes a reception unit 131 and a detection unit 132. The receiving unit 131 detects the amplitude SP of the standing wave S and outputs a detection signal having an amplitude corresponding to the amplitude SP. A detector 132 is connected to the receiver 131. The detection unit 132 records a modulation signal from the modulator 20 and a detection signal from the reception unit 131 (not shown), and synchronously detects the detection signal recorded in the recording unit using the modulation signal and detects the detection signal. And a calculation unit (not shown) that forms a signal and calculates a detection signal corresponding to the amplitude of the standing wave. Further, when receiving the detection signal from the reception unit 131, the detection unit 132 can send a reception confirmation signal to the modulator 20.

  Note that, similarly to the distance detection device 10a of the first example, the distance detection device 10b of the second example also includes the transmission unit 12b and the detection unit 13b separately. For example, the transmission unit is configured by one antenna. You may use 12b and the detection part 13b together. In this case, the apparatus can have a compact and simple structure.

FIG. 8 is a flowchart illustrating an operation for measuring the distance to the moving body M by the distance detection device 10b. FIG. 9 is a waveform diagram for explaining the operation of the distance detection apparatus 10b in the second example of the moving object distance detection system of FIG. 1, and FIG. 9A shows the frequency of the output signal and the reception. FIG. 9B is a diagram showing a relationship with the amplitude SP of the standing wave S at the position of the unit 131, and FIG. 9B shows the detection signal output from the detection unit 132 and the frequency f of the signal output from the frequency transmission unit 111. detection signal functions a (, f d ₁₎ which is formed from a diagram illustrating a.

Since the operation other than the frequency modulation is the same as the case where the distance calculation unit 14a obtains the minimum of the detection signal function A (f, d ₁ ) in the distance detection apparatus 10a of the first example, Only the operation of performing frequency modulation (steps S203 to S209 in FIG. 8) will be described.

  In step S203, the modulator 20 sets θ to an initial value (θ = 0). In step S204, the transmission unit 12b emits the traveling wave D having the frequency f of the initial frequency f + fdcos θ (θ = 0) toward the moving body M into the propagation medium. At this time, modulation information (modulation signal) of the output signal is transmitted from the modulator 20 to the detection unit 132. The traveling wave D emitted from the transmission unit 12b propagates through the propagation medium, reaches the moving body M, is reflected by the moving body M, becomes a reflected wave R, and is opposite to the traveling wave D, that is, the transmission unit 12b. It propagates in the propagation medium toward. Then, the traveling wave D and the reflected wave R interfere with each other, and a standing wave S is formed in the propagation medium between the transmission unit 12b and the moving body M.

  In step S205, the reception unit 131 of the detection unit 13b detects the amplitude SP of the standing wave S formed in the propagation medium between the transmission unit 12b and the moving body M, and sets the amplitude SP of the standing wave S. A corresponding detection signal is transmitted to the detector 132.

  In step S206, the detection unit 132 records the value P of the detection signal from the reception unit 131 on the recording unit in a one-to-one correspondence with the modulation information of the output signal transmitted from the modulator 20. At the same time, the detector 132 transmits a reception confirmation signal to the modulator 20.

  In step S207, the modulator 20 that has received the reception confirmation signal from the detection unit 132 determines whether θ = 2π. If it is determined that θ = 2π is not satisfied (NO in step S207), the process proceeds to step S208. If it is determined that θ = 2π (YES in step S207), the process proceeds to step S209.

  In step S208, the modulator 20 changes the frequency f of the signal transmitted by the frequency transmission unit 111 to f + fdcos θ (θ = θ + dθ). Then, since the frequency f of the traveling wave D emitted from the transmission unit 12b changes to f + fdcos θ (θ = θ + dθ), the amplitude SP of the standing wave S detected by the reception unit 131 of the detection unit 13b changes, and the reception unit The value of the detection signal sent from 131 to the detector 132 changes. This detection signal is recorded in the recording unit of the detection unit 132 in a one-to-one correspondence with the modulation information of the output signal of the transmission unit 11a. When receiving the reception confirmation signal from the detection unit 132 of the detection unit 13b again, the modulator 20 changes the frequency f of the signal transmitted from the frequency transmission unit 111 to f + fd cos θ (θ = θ + 2dθ). The processing from step S204 to S208 is repeated until θ = 2π, and when θ = 2π, the process proceeds to step S209.

  In step S209, the detection unit 132 forms a detection signal by performing synchronous detection using the recorded detection signal and modulation information. Since the detection unit 132 outputs a detection signal corresponding to the amplitude of the detection signal to the distance calculation unit 14a, the detection signal is made to correspond to the frequency information sent from the frequency control unit 112 to the distance calculation unit 14b on a one-to-one basis. And recorded in the recording unit of the distance calculation unit 14b.

Then, if the frequency is changed to the frequency control unit 112 causes the call to the frequency transmitter unit 111 to the final frequency from an initial frequency, the distance calculating unit 14b, the detection signal function A (f, d ₁₎ is formed.

As shown in FIG. 9B, the detection signal function A (f, d ₁ ) increases monotonously in the vicinity of the frequency (f _n , f _{n + 2} , f _{n + k} ) where the amplitude SP of the standing wave S is minimized. In the vicinity of the frequency (f _{n + 1} ) at which the amplitude SP of the standing wave S is maximized, the detection signal function A (f, f) is before and after the frequency at which the amplitude SP of the standing wave S is minimized or maximized. It becomes a curve in which the sign of the value P of the detection signal of d ₁ ) changes.

  Therefore, according to the distance detection device 10b in the second example, the frequency f at which the amplitude SP of the standing wave S is minimized can be accurately detected, and the measurement error can be reduced.

  In the second example, two or more frequencies of the output signal at which the detection signal function is minimized are obtained, and the distance between the moving body M and the transmission unit 12b is measured from these frequencies. However, the present invention is not particularly limited thereto, and two or more frequencies of the output signal at which the detection signal function is maximized may be obtained, and the distance between the moving body M and the transmission unit 12b may be measured from these frequencies.

  FIG. 10 is a block diagram schematically showing the configuration of the distance detection device 10c in the third example of the moving object distance detection system of FIG.

  The distance detection apparatus 10c in the third example includes a transmission unit 11c, a transmission unit 12c, a spectroscopic unit 31, a reflection mirror 32, a detection unit 13c, and a distance calculation unit 14c. In the third example, the intensity of light transmitted from the transmitting unit 11c is periodically changed, and the standing wave S formed between the spectroscopic unit 31 and the moving body M is used to reach the moving body M. Detect distance.

  The method for calculating the distance from the spectroscopic unit 31 to the moving body M based on the detection signal detected by the detection unit 13c is the same as that of the distance detection device 10a of the first example described above. Will describe only the configuration of the distance detecting device 10c in the third example.

  The transmission unit 11c includes a frequency transmission unit 111 'and a frequency control unit 112'. The frequency transmitter 111 ′ outputs light emission intensity of the transmitted light and the intensity change thereof to a constant frequency f. The frequency control unit 112 'controls the frequency f of the light emission intensity change of the light output from the frequency transmission unit 111'. Further, the frequency control unit 112 ′ is information on the frequency f of the light emission intensity change of the light transmitted from the frequency transmission unit 111 ′, for example, the numerical value or frequency of the frequency f of the light emission intensity change of the light transmitted from the frequency transmission unit 111 ′. The signal etc. which have the same frequency f as the light emission intensity change of the light which transmission part 111 'transmits are output.

  The transmission part 12c is comprised, for example with a laser, a light emitting diode, etc., and is connected with the transmission part 11c. The transmission unit 12c has the same frequency f as the signal transmitted by the frequency transmission unit 111 ′ of the transmission unit 11c in a propagation medium such as air or water or in a vacuum existing between the transmission unit 12c and the moving body M. Emits light having

  Between the transmission unit 12c and the moving body M, a spectroscopic unit 31 configured by, for example, a beam splitter or the like is provided. The spectroscopic unit 31 splits the light emitted from the transmission unit 12 c into two, and emits one of the split light into a propagation medium existing between the moving body M and the light. One light split in the direction of the moving body M is reflected by the moving body M, and the light reflected by the moving body M is reflected by the spectroscopic unit 31 in the direction of the detecting unit 13c. For this reason, in the propagation medium between the spectroscopic unit 31 and the moving body M, the light transmitted through the spectroscopic unit 31 interferes with the reflected light reflected and returned by the mobile unit M, and the standing wave S is generated. It is formed. The other light split by the spectroscopic unit 31 travels to the reflecting mirror 32 provided on the side of the spectroscopic unit 31. In addition, the spectroscopic unit 31 reflects the reflected light that has been reflected back by the moving body M toward the detection unit 13c.

  The reflection mirror 32 is provided at a position separated from the spectroscopic unit 31 by a predetermined distance L, and reflects the other light split by the spectroscopic unit 31 toward the spectroscopic unit 31 again. The light reflected by the reflection mirror 32 passes through the spectroscopic unit 31 and travels toward the detection unit 13c.

  A detection unit 13c is provided at a position symmetrical to the reflecting mirror 32 with the spectroscopic unit 31 in between. The detection unit 13 c reflects the amplitude of the standing wave S formed in the propagation medium between the spectroscopic unit 31 and the moving body M by the emission intensity of the light reflected by the moving body M and the reflection mirror 32. The detection signal corresponding to the detected amplitude SP of the standing wave S is output. The detection unit 13c includes a photo detector that detects a detection signal corresponding to the amplitude SP of the standing wave S, for example, a detection signal obtained by detecting the emission intensity of the amplitude SP of the standing wave S and converting the emission intensity into a voltage. The detection signal output from the photodetector outputs a current or voltage that is the same as the amplitude SP of the standing wave S or proportional to the square of the amplitude SP.

  A distance calculation unit 14c is connected to the detection unit 13c. The distance calculation unit 14c includes, for example, a digital signal processor (DSP), a memory, and the like, and includes a recording unit that records input data and a calculation unit that calculates data recorded in the recording unit. The distance from the spectroscopic unit 31 to the moving body M is calculated by the calculation unit.

Light intensity change obtained by adding the intensities of both the light reflected by the moving body M in the spectroscopic unit 31 (reflected wave R) and the light reflected by the reflecting mirror 32 (traveling wave D). Since the distance between the spectroscopic unit 31 and the reflecting mirror 32 is L, the magnitude of the amplitude of is equal to the amplitude of the standing wave that can be placed at a position away from the spectroscopic unit 31 toward the moving body M by L. become. Therefore, if the distance L between the spectroscopic unit 31 and the reflection mirror 32 is known, the distance d ₁ from the position separated from the spectroscopic unit 31 toward the moving body M by the distance L to the moving body M is detected. be able to.

The detection unit 13c reflects the light emission intensity of the light reflected by the spectroscopic unit 31 detected by the detection unit 13c and reflected by the reflection mirror 32, and the light reflected by the moving body M that is also detected by the detection unit 13c. Is detected. The detecting unit 13c is reflected by the light intensity reflected by the spectroscopic unit 31 detected by the detecting unit 13c and reflected by the reflecting mirror 32, and by the moving body M similarly detected by the detecting unit 13c. The amplitude SP of the standing wave S at a position away from the spectroscopic unit 31 toward the moving body M by the same distance L from the spectroscopic unit 31 and the reflecting mirror 32 is obtained by adding together the emission intensity of the measured light. A detection signal corresponding to the amplitude SP of the standing wave S is transmitted to the distance calculation unit 14a. The distance calculation unit 14 performs the same processing as in Steps S5 to S11 in FIG. 4, whereby the distance d between the position separated by the same distance L from the spectroscopic unit 31 and the reflection mirror 32 and the moving body M. ₁ and finally adding the distance L and the distance d ₁ stored in the storage means such as a memory, the distance from the spectroscopic unit 31 to the moving body M, that is, from the moving body distance detection system. The distance to the moving body M is calculated.

  The distance calculation unit 14c is also connected to the frequency control unit 112 ′ of the transmission unit 11c and relates to the frequency f of the light emission intensity of the light transmitted from the frequency transmission unit 111 ′ from the frequency control unit 112 ′ of the transmission unit 11c. In addition to receiving information (hereinafter referred to as frequency information of the output signal), a reception confirmation signal is sent to the frequency control unit 112 ′ of the transmission unit 11c when the detection signal is received from the detection unit 13c.

  Therefore, according to the distance detection device 10c of the third example, the distance from the spectroscopic unit 31 to the moving body M can be measured, similarly to the distance detection device 10a of the first example. Moreover, even if the distance to the moving body M is a short distance of several tens of centimeters or less, it can be measured with high accuracy.

Furthermore, the frequency f of the emission intensity of the light output from the frequency oscillator 111 ', be varied randomly between the initial frequency f _L and a final frequency f _U, originating from another distance detecting apparatus 10c light Therefore, it is possible to prevent the measurement error from being remarkably increased or impossible to be measured.

  Furthermore, since the fluctuation periods of the amplitudes SP of the plurality of standing waves S can be obtained, the distances between the plurality of moving bodies M and the spectroscopic unit 31 can be measured.

The distance calculation unit 14c obtains two or more frequencies f of the output signal at which the detection signal function A (f, d ₁ ) is either maximum or minimum, and based on these frequencies f, the moving object M, the spectroscopic unit 31 and when determining the distance between, as 0Hz initial frequency f _L, may be changed frequency f of the output signal to any final frequency f _U. In this case, the detection signal functions A (f, _{d 1)} in always detected signal function A when the frequency f of the output signal is 0 (f, _{d 1)} becomes maximum. Therefore, only the frequency of the output signal at which the detection signal function A (f, d ₁ ) becomes maximum between the initial frequency f _L and the final frequency f _U is obtained, and the frequency f and the initial frequency f _L Can be used to determine the distance between the moving object M and the spectroscopic unit 31.

  Furthermore, similarly to the distance detection device 10b of the second example, a modulator that performs frequency modulation on the emitted light intensity may be provided in the transmission unit 11c, and a reception unit and a detection unit may be provided in the detection unit 13c. In this case, similarly to the distance detector 10b of the second example, the frequency at which the amplitude SP of the standing wave S is either minimum or maximum can be accurately detected, and the measurement error can be reduced.

  In the present embodiment, the transmitters 11a, 11b, and 11c correspond to transmitters, the transmitters 12a, 12b, and 12c correspond to transmitters, the detectors 13a, 13b, and 13c correspond to detectors, and distance calculation. The units 14a, 14b, and 14c correspond to distance calculation means, the modulator 20 corresponds to modulation means, the reception section 131 corresponds to reception means, the detection section 132 corresponds to detection means, and the spectroscopic section 31 corresponds to spectroscopic means. It corresponds to.

  FIG. 11 is a block diagram schematically showing the configuration of a distance detection device 10d in the fourth example of the moving object distance detection system of FIG. The distance detection device 10d of the present invention includes a plurality of distance detection devices 10a1 and 10a2. In the present embodiment, two distance detection devices 10a are used, and each will be described as a distance detection device 10a1 and a distance detection device 10a2. A control device 2 is connected to the plurality of distance detection devices 10a1 and 10a2. This control device 2 is for operating a plurality of distance detection devices 10a1 and 10a2 in synchronization, and controls so that electromagnetic waves are simultaneously emitted from the distance detection devices 10a1 and 10a2 into the propagation medium.

  A computing device 3 is connected to the plurality of distance detection devices 1. The arithmetic device 3 receives the distance from the detection unit 13a calculated by the distance calculation unit 14a of each of the distance detection devices 10a1 and 10a2 to the moving body M. The arithmetic device 3 calculates the moving body M from the distances from the detection unit 13a to the moving body M in the input distance detection devices 10a1 and 10a2 and the relative positions of the detection units 13a of the distance detection devices 10a1 and 10a2. The spatial coordinates of are calculated.

  That is, the distance detection device 10d that detects the spatial coordinates of the moving body includes the distance detection devices 10a1 and 10a2 that the moving body M operates in synchronization with the plurality of distance detection devices 10a1 and 10a2, From the distance between the detection unit 13a calculated by the distance calculation unit 14a of the distance detection devices 10a1 and 10a2 and the moving body M and the relative position of the detection units 13a of the distance detection devices 10a1 and 10a2, It is characterized by comprising an arithmetic unit 3 for calculating the spatial coordinates.

  FIG. 12 is a schematic diagram for explaining a position measurement method by the distance detection device 10d in the fourth example of the moving object distance detection system of FIG.

  The control device 2 controls the two distance detection devices 10a1 and 10a2 to synchronize and simultaneously transmit electromagnetic waves. Then, a standing wave S1 is formed between the distance detection device 10a1 and the moving body M, a standing wave S2 is formed between the distance detection device 10a2 and the moving body M, and the moving body M is moved from the distance detection device 10a1. The distance d1 from the distance detection device 10a2 to the moving body M is calculated. The distances d1 and d2 from the distance detection devices 10a1 and 10a2 to the moving body M are input to the arithmetic device 3.

  The arithmetic device 3 calculates the relative positions of the distance detection devices 10a1 and 10a2 and the moving body M based on the distances d1 and d2 input from the two distance detection devices 10a1 and 10a2. Specifically, as shown in FIG. 12, when the distance of the line segment R connecting the distance detection device 10a1 and the distance detection device 10a2 is r, the distance d ′ from the intermediate position P of the line segment R to the moving body M Is calculated by the following equation (5).

^{d '= {(d1 2/} 2) + (d2 2/2) - (r 2/4)} 1/2 ···· (5)

  Further, the angle θ formed by the perpendicular bisector of the line segment R and the line segment D connecting the intermediate position P and the moving body M is calculated by the following equation (6).

sin θ = (d1 ² −d2 ² ) / 4rd ′ (6)

  Thus, the distance d ′ from the intermediate position of each distance detecting device to the moving body is calculated, and the perpendicular bisector of the line segment R and the line segment D connecting the intermediate position P and the moving body M are formed. By calculating the angle θ, it is possible to grasp the relative positions of the distance detection devices 10a1 and 10a2 and the moving body M on the plane where the distance detection devices 10a1 and 10a2 and the moving body M exist.

  In addition, by providing three distance detection devices 10a, the relative positional relationship between each distance detection device and the moving body can be grasped three-dimensionally.

  In the present embodiment, the distance detection device 10d has been described as a configuration including a plurality of distance detection devices 10a. However, the present invention is not particularly limited thereto, and the distance detection device 10d includes a plurality of distance detection devices 10b. Or a plurality of distance detection devices 10c. Furthermore, the distance detection device 10d may be configured by combining a plurality of distance detection devices 10a, 10b, and 10c.

  Next, a moving body distance detection system according to a second embodiment of the present invention will be described. In the mobile body position detection system according to the second embodiment, the distance between the distance detection device and the water surface of the river is detected, and the detected distance is transmitted to the monitoring station by the communication device.

  FIG. 13 is a block diagram schematically showing the configuration of the moving object distance detection system in the second embodiment of the present invention.

  A moving body distance detection system 100b according to the second embodiment includes a distance detection device 10, a power storage unit 200, a solar cell 300, and a communication device 500. In addition, since the electrical storage part 200 and the solar cell 300 in 2nd Embodiment are the structures similar to the electrical storage part 200 in 1st Embodiment, and the solar cell 300, description is abbreviate | omitted.

  The distance detection device 10 detects the distance to the water surface SM of the river that is a moving body using the standing wave S, and outputs the detected distance to the water surface SM to the communication unit 500. The communication unit 500 transmits the distance to the water surface SM detected by the distance detection device 10 to a monitoring station (not shown). The distance detection device 10 includes the distance detection device 10a in the first example, the distance detection device 10b in the second example, the distance detection device 10c in the third example, and the distance detection device 10d in the fourth example. One of them can be used.

  In this way, the standing wave S formed in the propagation medium between the distance detection device 10 and the water surface SM is detected, and the distance between the distance detection device 10 and the water surface is determined based on the detected standing wave S. Calculated. Therefore, the water level of the river can be measured by detecting the distance between the distance detection device 10 and the water surface SM of the river, which is a moving body, and the distance detection device can be used as a water level sensor.

  In the present embodiment, the distance detection device 10 detects the distance to the water surface of a river that is a moving body, but the present invention is not particularly limited to this, for example, the distance to the water surface of a lake or the water surface of the sea. May be used as long as the amount of water is detected.

  Moreover, in addition to the structure shown in FIG. 13, you may provide the sluice gate control means which controls opening and closing of a sluice. For example, the distance detection device 10 and the sluice control means are connected, and when the distance to the water surface detected by the distance detection device 10 is equal to or less than a predetermined distance, the sluice is opened and detected by the distance detection device 10. The amount of water can be adjusted by closing the sluice when the distance to the water surface exceeds a predetermined distance.

  Next, a moving object distance detection system according to a third embodiment of the present invention will be described. In the moving body position detection system according to the third embodiment, the distance between the host vehicle on which the distance detection device is mounted and the front vehicle traveling in front of the host vehicle is detected, and a warning sound or the like is based on the detected distance. Is output.

  FIG. 14 is a block diagram schematically showing the configuration of the moving object distance detection system in the third embodiment of the present invention.

  A moving body distance detection system 100c according to the third embodiment includes a distance detection device 10, a power storage unit 200, a solar battery 300, a determination unit 400, and a warning sound output unit 600. The moving body distance detection system 100c is provided in the own vehicle. Moreover, since the electrical storage part 200 and the solar cell 300 in 3rd Embodiment are the structures similar to the electrical storage part 200 in 1st Embodiment, and the solar cell 300, description is abbreviate | omitted.

  The distance detection device 10 detects the distance to the front vehicle ZC, which is a moving body traveling in front of the host vehicle JC, using the standing wave S, and determines the detected distance to the front vehicle ZC. Output to the unit 400. The distance detection device 10 includes the distance detection device 10a in the first example, the distance detection device 10b in the second example, the distance detection device 10c in the third example, and the distance detection device 10d in the fourth example. One of them can be used.

  The determination unit 400 determines whether the distance to the front vehicle ZC output from the distance detection device 10 is within a predetermined distance set in advance, and the distance to the front vehicle ZC is within the predetermined distance. If it is determined that there is, an output signal for outputting a warning sound is output to the warning sound output unit 600. The warning sound output unit 600 outputs a warning sound for notifying the driver of the host vehicle JC that the host vehicle JC is approaching the forward vehicle ZC traveling ahead.

  In the present embodiment, determination unit 400 corresponds to a determination unit, warning sound output unit 600 corresponds to an alarm unit, and lighting control unit 410 corresponds to an illumination lighting unit.

  Thus, when the moving body distance detection system 100c is provided in the own vehicle JC and the moving body is the front vehicle ZC traveling in front of the own vehicle JC, the distance detection device 10 provided in the own vehicle JC The standing wave S formed in the propagation medium between the vehicle JC and the preceding vehicle ZC is detected, and the distance between the host vehicle JC and the preceding vehicle ZC is calculated based on the detected standing wave S. The It is determined whether or not the distance between the host vehicle JC and the preceding vehicle ZC is within a predetermined distance set in advance, and the distance between the host vehicle JC and the preceding vehicle ZC is within a predetermined distance. When the judgment is made, a warning sound for preventing rear-end collision is output, so that the driver riding in the host vehicle JC knows that there is a risk of rear-end collision with the preceding vehicle ZC by a rear-end collision prevention alarm such as a warning sound. It is possible to prevent a rear-end collision with a moving body.

  In the present embodiment, the distance detection device 10 detects the distance to the front vehicle ZC, which is a moving body. However, the present invention is not particularly limited to this. For example, the moving body is a human and the distance to the human is May be detected. In this case, the distance detection device 10 detects the distance to the pedestrian (human) ahead of the host vehicle JC, and the determination unit 400 determines that the distance from the host vehicle JC to the pedestrian is within a predetermined distance. In addition, the warning sound output unit 600 outputs a warning sound for notifying the driver of the host vehicle JC that the host vehicle JC is approaching a pedestrian ahead. Thereby, the traffic accident with a pedestrian can be prevented.

  In the present embodiment, the moving body distance detection system 100c is configured to include the power storage unit 200 and the solar battery 300. However, the present invention is not particularly limited to this, for example, when a vehicle travels. A battery that stores electricity may be used.

1 is a block diagram schematically showing a configuration of a moving object distance detection system in a first embodiment of the present invention. It is a block diagram which shows roughly the structure of the 1st example of the distance detection apparatus 10 in the mobile body distance detection system of FIG. 5 is a schematic explanatory diagram for explaining formation of a standing wave S. FIG. It is a figure which shows the flowchart of the operation | work which measures the distance to the moving body M by the distance detection apparatus 10a. It is a wave form diagram for demonstrating operation | movement of the distance detection apparatus 10a in the 1st example of the mobile body distance detection system of FIG. It is a figure which shows the flowchart of the operation | work which calculates | requires 2 or more of the frequency of the output signal from which a detection signal function becomes the maximum minimum, and measures the distance between the mobile body M and the transmission part 12a. It is a block diagram which shows roughly the structure of the distance detection apparatus 10b in the 2nd example of the mobile body distance detection system of FIG. It is a figure which shows the flowchart of the operation | work which measures the distance to the moving body M by the distance detection apparatus 10b. It is a wave form diagram for demonstrating operation | movement of the distance detection apparatus 10b in the 2nd example of the mobile body distance detection system of FIG. It is a block diagram which shows roughly the structure of the distance detection apparatus 10c in the 3rd example of the mobile body distance detection system of FIG. It is a block diagram which shows roughly the structure of the distance detection apparatus 10d in the 4th example of the mobile body distance detection system of FIG. It is the schematic for demonstrating the position measuring method by the distance detection apparatus 10d in the 4th example of the mobile body distance detection system of FIG. It is a block diagram which shows roughly the structure of the moving body distance detection system in the 2nd Embodiment of this invention. It is a block diagram which shows roughly the structure of the moving body distance detection system in the 3rd Embodiment of this invention.

Explanation of symbols

10a, 10b, 10c Distance detectors 11a, 11b, 11c Transmitters 12a, 12b, 12c Transmitters 13a, 13b, 13c Detectors 14a, 14b, 14c Distance calculator 20 Modulator 31 Spectrometer 32 Reflecting mirrors 100a, 100b , 100c Moving object distance detection system 111, 111 ′ Frequency transmission unit 112, 112 ′ Frequency control unit 131 Reception unit 132 Detection unit 200 Power storage unit 300 Solar cell 400 Judgment unit 410 Lighting control unit 420 Illumination lamp 500 Communication device 600 Warning sound output Part S Standing wave D Traveling wave R Reflected wave

Claims (12)

A mobile object distance detection system for detecting a distance to a mobile object to be measured,
Transmitting means for outputting an output signal having a variable frequency;
Transmitting means for emitting an electromagnetic wave having the same frequency as the frequency of the output signal output by the transmitting means to a propagation medium existing between the moving body;
It is provided between the transmitting means and the moving body, detects the amplitude of the standing wave formed in the propagation medium between the transmitting means and the moving body, and detects the detected standing wave amplitude. Detection means for outputting a corresponding detection signal;
The detection signal output by the detection means and the frequency information of the output signal output by the transmission means are input to form a detection signal function indicating the value of the detection signal with respect to the frequency of the output signal, and the detection signal function Is transformed to form a conversion function, the period of the detection signal function is calculated from the conversion function , and the distance between the moving object distance detection system and the moving object is calculated from the calculated period of the detection signal function and distance calculation means for,
And determining means for determining whether or not the distance between the moving object distance detection system calculated by the distance calculating means and the moving object is within a predetermined distance set in advance. Mobile object distance detection system. A mobile object distance detection system for detecting a distance to a mobile object to be measured,
Transmitting means for outputting an output signal having a variable frequency;
Transmitting means for emitting light having the same frequency as the frequency of the output signal output by the transmitting means to a propagation medium existing between the moving body;
Spectroscopic means for splitting the light emitted from the transmitting means into two, and emitting one of the split light to a propagation medium existing between the moving body,
Reflecting means for reflecting the other light split by the spectroscopic means;
The amplitude of the standing wave formed in the propagation medium between the spectroscopic means and the moving body is determined based on the emission intensity of one light reflected by the moving body and the other light reflected by the reflecting means. Detecting means for detecting based on the emission intensity and outputting a detection signal corresponding to the detected amplitude of the standing wave;
The detection signal output by the detection means and the frequency information of the output signal output by the transmission means are input to form a detection signal function indicating the value of the detection signal with respect to the frequency of the output signal, and the detection signal function Is transformed to form a conversion function, the period of the detection signal function is calculated from the conversion function , and the distance between the moving object distance detection system and the moving object is calculated from the calculated period of the detection signal function and distance calculation means for,
And determining means for determining whether or not the distance between the moving object distance detection system calculated by the distance calculating means and the moving object is within a predetermined distance set in advance. Mobile object distance detection system.   The distance calculation means receives the detection signal output from the detection means and the frequency information of the output signal output from the transmission means, and forms a detection signal function indicating the value of the detection signal with respect to the frequency of the output signal And detecting the frequency of at least two or more output signals at which the detection signal function is maximized or minimized, and maximizing two selected frequencies of the two or more output signals and the maximum between the two selected frequencies or 3. The moving object distance detection system according to claim 1, wherein a distance between the moving object distance detection system and the moving object is calculated from the number of frequencies of the output signal that is minimized. The transmitting means includes modulation means for frequency modulating the output signal,
The detection means detects the amplitude of the standing wave, outputs a detection signal having an amplitude corresponding to the amplitude, and receives a modulation signal from the modulation means. The mobile body distance detection system according to any one of claims 1 to 3, further comprising: detection means for forming a detection signal by synchronous detection and outputting a detection signal corresponding to the amplitude of the detection signal. The mobile body includes a person in a road facility,
The detection means outputs a detection signal corresponding to the amplitude of a standing wave formed in the propagation medium between the transmission means and the human,
The movement according to any one of claims 1 to 4, wherein the distance calculation means calculates a distance between the moving object distance detection system and the human based on a detection signal output by the detection means. Body distance detection system. The mobile body includes a vehicle in a road facility,
The detection means outputs a detection signal corresponding to the amplitude of a standing wave formed in the propagation medium between the transmission means and the vehicle;
The movement according to any one of claims 1 to 4, wherein the distance calculation means calculates a distance between the moving object distance detection system and the vehicle based on a detection signal output by the detection means. Body distance detection system.   When the determination means determines that the distance between the moving body distance detection system and the moving body is within the predetermined distance, a rear collision prevention alarm is generated to prevent a rear collision with the moving body. The moving body distance detection system according to claim 1, further comprising an alarm unit.   The apparatus further comprises illumination lighting means for turning on illumination when the determination means determines that the distance between the moving object distance detection system and the moving object is within the predetermined distance. The moving body distance detection system in any one of Claims 1-6.   And an information notification device for notifying information about the periphery of the mobile body when the distance between the mobile body distance detection system and the mobile body is determined to be within the predetermined distance by the determination unit. The moving body distance detection system according to any one of claims 1 to 6.   A light emitting device for guiding the moving body by light emission when the determining means determines that the distance between the moving body distance detection system and the moving body is within the predetermined distance; The moving body distance detection system according to any one of claims 1 to 6. The mobile body includes a river surface,
The detection means outputs a detection signal having an amplitude corresponding to a standing wave formed in the propagation medium between the transmission means and the water surface;
The movement according to any one of claims 1 to 4, wherein the distance calculation means calculates a distance between the moving body distance detection system and the water surface based on a detection signal output by the detection means. Body distance detection system. It further comprises power storage means for storing power generated by the solar cell,
The mobile body distance detection system according to claim 1, wherein electric power stored by the power storage unit is used as a power source.

Images