JP2001013238A - Object detecting apparatus and confirmation device for its operation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an object detecting apparatus which can be installed in response to directivity irrespective of a dead distance. SOLUTION: A transmitter 1 sends out radar waves toward a detection area 7. A receiver 3 receives reflected radar waves of the radar waves. A waveguide 5, on which a part of the radar waves sent out to the detection area 7 is incident, passes the incident radar waves. A received-signal processing part 6 detects the existence of an object 9 to be detected at the outside of the detection area 7 on the basis of the received signal of the reflected radar waves supplied from the receiver 3, and it confirms the operation normality of a detecting system on the basis of the received signal of the radar waves, for inspection, which pass the waveguide 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object detecting device and an operation confirming device for confirming a normal operation thereof. More specifically, the present invention relates to an object detection device using a radar, the object detection device including a confirmation unit that can confirm that an object detection system is operating normally. INDUSTRIAL APPLICABILITY The object detection device according to the present invention is suitable for being mounted on a moving body such as an automobile, and is also applicable to an intelligent transportation system (ITS).

[0002]

2. Description of the Related Art In an object detection device which transmits a radar wave to an area where an obstacle is detected (detection area) and detects an object by receiving a reflected radar wave, the object detection device monitors the detection area. Confirmation is required for safety. Conventionally, such confirmation has been performed by confirming reception of a reflected radar wave from the inspection reflector at a predetermined position.

For example, an ultrasonic sensor for traffic control detects the presence / absence of a vehicle in a detection area and confirms normal operation based on a radar wave reflected from a road surface received when the vehicle is absent. Japanese Patent Application No. 9-305932 discloses an “optical barrier device” that includes an optical radar sensor and a light beam scanning unit that scans a light beam in space, and an inspection provided in advance at a predetermined scanning angle. The normality is confirmed by receiving the reflected light from the reflector for use. These are all
It is assumed that the object detection device is fixed in space, that is, the positional relationship between the inspection reflector and the device is unchanged. Therefore, when the object detection device is mounted on a moving object, the relative position (distance or angle) between the inspection reflector and the device changes every moment as the object is moved. The above approach requires further treatment.

As an inspection means of an object detection device mounted on a moving body, there is, for example, an ultrasonic monitoring device described in JP-A-3-238384. In this prior art, a reflector (reference reflector) is attached to the vehicle surface near the ultrasonic vibrator, and when the reflection level of the reflected radar wave from the reflector becomes lower than a set value, it is determined that there is an abnormality. 4 shows an inspection configuration including a control unit that outputs an abnormal signal. Specifically, an ultrasonic radar sensor is attached to a bumper of an automobile, and a reference reflection object is fixed to a surface of the bumper at a predetermined distance from the sensor. The reason for mounting the antenna at a predetermined distance is to detect a reflected radar wave from the reference reflecting object separately from reverberation after transmission.

[0005] The above publication discloses a transmission time of 0.2 m.
Since the reverberation time is about 0.8 ms in the case of s, it is described that it is necessary to mount the reflecting object and the sensor at a distance of about 15 cm or more, which is a dead distance determined by the transmission time and the reverberation time.

However, according to the technique described in the above-mentioned patent publication, the sum of the transmission time and the reverberation time increases as the transmission time is lengthened or the gain of the receiving amplifier is increased to extend the detection area to a distant place. Since the determined dead distance increases, it is necessary to install the sensor and the reference reflecting object further apart.

[0007] In addition, the position must be within a range where the transmission radar wave reaches. For example, when an object detection device and a reference reflective object are mounted side by side on the bumper surface of a vehicle, they must be separated from each other as the dead distance increases, and the radar must be pointed so that radar waves reach the reference reflective object. Sex must be determined. In other words, the more the object detection device and the reference reflection object are installed, the more the directivity must be increased. This means that in the method described in the above-mentioned patent publication, it is necessary to design the object detection device in association with the dead distance and the directivity.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an operation check device which can be installed in accordance with directivity regardless of a dead distance, and an object detecting device having the operation check device. .

Another object of the present invention is to provide an operation check device capable of simply and reliably eliminating the effects of reverberation, and an object detection device having the operation check device.

Still another object of the present invention is to provide an operation check device capable of easily and reliably checking the range of a space detection region, and an object detection device having the operation check device. It is.

Still another object of the present invention is to provide an operation checking device capable of easily and surely checking the intensity of a transmitted radar wave, and an object detecting device having the operation checking device. It is to be.

[0012]

In order to solve the above-mentioned problems, an object detecting apparatus according to the present invention transmits radar waves to a detection area by a transmitter and receives reflected radar waves as a basic operation. It is assumed that there is an object when it is received by the container. The feature of the object detection device according to the present invention resides in that the object detection device includes a waveguide and a reception signal processing unit that performs processing of an inspection radar wave passing through the waveguide. The waveguide and the reception signal processing unit constitute an operation confirmation device or unit.

[0013] A part of the radar wave transmitted to the detection area from one end side of the waveguide is made incident, passes the incident radar wave, and supplies the passed radar wave to the receiver.

The reception signal processing section detects presence or absence of an object in the detection area from a reception signal of the reflected radar wave supplied from the receiver, and detects the radar wave passing through the waveguide. Check the normal operation of the detection system from the received signal.

According to the object detecting device having the above configuration, the radar wave passing through the waveguide is delayed by the propagation time when passing through the waveguide. Propagation delay time in the waveguide, for example, by changing the length of the waveguide, or by changing the propagation speed,
Can be set arbitrarily. Therefore, the effect of reverberation can be easily and reliably eliminated. Therefore, it is not necessary to consider the spatial arrangement of the object detection device and the reference reflection object in order to distinguish it from the inspection radar wave.

In addition, the incident end of the waveguide can be set at an arbitrary position within a range where a radar wave having a predetermined intensity or more reaches.
Therefore, it is possible to realize an object detection device having an operation check unit that can be installed according to directivity regardless of the dead distance.

In the normal operation check of the object detection device, the reception intensity of the inspection radar wave may be checked. Therefore, the effect of reverberation can be easily and reliably eliminated.

Further, by arranging the incident end of the waveguide at the end of the detection area, for example, the intensity of the radar wave can be directly confirmed in the detection area.

Further, by adjusting the attenuation factor in the waveguide, the ratio between the incident intensity and the output intensity can be set.
The intensity of the transmitted radar wave can be easily and reliably confirmed.

Other objects, configurations and advantages of the present invention will be described in more detail with reference to the accompanying drawings which are embodiments. The figures are merely examples.

[0021]

FIG. 1 is a diagram showing the concept of an object detecting device according to the present invention. The illustrated object detection device shows an example of application to a type in which a transmitter and a receiver are separated. The illustrated object detection device includes a transmitter 1 and a receiver 3.
, A waveguide 5 and a received signal processing unit 6. Transmitter 1
Transmits a radar wave toward the detection area 7. Radar waves include ultrasonic waves, electromagnetic waves or light waves. The detection area 7 is shown as an area inside the boundary line N. The transmitter 1 is excited by the transmission unit 8.

The receiver 3 is provided separately from the transmitter 1, and receives a reflected radar wave of a radar wave. The radar wave transmitted from the transmitter 1 is reflected by an object 9 such as an obstacle, and the reflected radar wave is received by the receiver 3.

The incident end 11 of the waveguide 5 can be arranged at an arbitrary position within a range where a radar wave having a predetermined intensity or more reaches. In the illustrated embodiment, the input end 11 of the waveguide 5 is provided inside the detection area 7. The radar wave transmitted from the transmitter 1 is sent to the detection area 7 and the waveguide 5
Is also incident. Then, the light propagates through the waveguide 5 and is emitted from the emission end 12.
Are emitted as radar radar waves for inspection. The outgoing end 12 is directed to the receiver 3. As a result, the receiver 3 receives the reflected radar wave from the detected object 9 such as an obstacle existing inside the detection area 7 and also receives the inspection radar wave.

The reception signal processing unit 6 detects the presence or absence of the detection object 9 inside the detection area 7 from the reception signal of the reflected radar wave supplied from the reception unit 3, and performs an inspection through the waveguide 5. Check the normal operation of the detection system from the received radar wave signal. The reception signal processing unit 6 constitutes an operation check device or means together with the waveguide 5. The receiver 3 can also be considered as a part of the operation check device or means.

The reception time of the inspection radar wave in the reception signal processing unit 6 is determined by the propagation time from the transmitter 1 to the incident end 11,
If the propagation time from the output end 12 to the receiver 3 is neglected for the time being, the propagation time when passing through the inside of the waveguide 5 can be substantially adjusted. The propagation time T is given by T = L / v, where L is the length of the waveguide, and v is the propagation speed of the radar wave for inspection. Therefore, the reception time can be set arbitrarily by selecting the length L and the propagation speed v.

The propagation speed v can be adjusted by selecting the propagation medium of the waveguide 5. For example, in an ultrasonic radar sensor, the speed of sound, which is the propagation speed, is about 330 m / s in air.
About 190 m / s in carbon disulfide,
It depends on the propagation medium, such as about 970 m / s in helium.

The input end 11 and output end 12 of the waveguide 5
Is sealed with an object that allows sound waves to pass therethrough and blocks the gas, and a gas having an appropriate sound speed is sealed inside the waveguide 5, so that the propagation speed in the waveguide 5 changes. If the propagation medium of the waveguide 5 is a metal, the speed of sound is about 10 times that of air.

A portion for changing the propagation speed may be provided only in a part of the waveguide 5. Thus, by adjusting the length L and selecting the propagation medium, the propagation time of the inspection radar wave passing through the waveguide 5 can be arbitrarily set. It is also apparent that a similar configuration can be adopted in an object detection device of a type using light (electromagnetic waves) as radar waves. Also in this case, the propagation time T = L / v for the length L of the waveguide 5 and the propagation velocity v. The speed depends on the refractive index of the medium.

Further, the object detection device may be a system that detects the distance to the object 9 from the phase difference between the transmitted radar wave and the received reflected radar wave. In this case, the above-described propagation time T can be replaced with the phase difference R and applied. The length of the waveguide 5 is L, and the wavelength in the waveguide 5 is λ.
Then, the phase difference is almost given by R = 2πL / λ10φ.

Therefore, it is no longer necessary to ensure a dead space for spatially disposing a dead distance for distinguishing between reverberation and an inspection radar wave, which is particularly problematic when using sound waves. The incident end 11 of the waveguide 5 may be at any position as long as it can receive the radar wave transmitted from the transmitter 1. For example, it may be close to the transmitter 1. There is no need to consider the dead distance, and it can be installed arbitrarily according to the directivity of the detection device.

Since the radar wave reflected from the object 9 inside the detection area 7 and the radar wave for inspection need to be distinguished from each other, the reception time may be determined immediately after the reverberation after transmission disappears, or after the detection. After the round-trip time to the end of zone 7 has elapsed, it is usually selected. The circuit configuration for confirming the normality based on the reception of the inspection radar wave, which will be described later, is described in detail.

FIG. 2 is a diagram showing a configuration for confirming the range of the detection area. In the embodiment shown in FIG. 2, the detection area 7 and the waveguide 5 are used to more clearly confirm the range of the detection area 7.
2 illustrates an arrangement relationship with the incident end 11. Dashed line N
Indicates a boundary that defines the range of the detection area 7 in a normal state. Actually, there is no clear boundary as shown by a dashed line N, but for convenience of explanation, the boundary is shown by a dashed line N as shown.

The incident end 11 is transmitted from the transmitter 1 and
It is arranged such that a radar wave passing substantially on the boundary N is incident. The inspection radar wave emitted from the emission end 12 of the waveguide 5 is received by the receiver 3, and it is detected from the reception intensity that the detection area 7 has a normal range.

When the detection area 7 is reduced, for example, as shown by a dotted line M, the intensity of the radar wave incident on the incident end 11 of the waveguide 5 is reduced, and the inspection signal received by the receiver 3 is used. The intensity of the radar wave also decreases, and it is detected that the detection area 7 is smaller than the normal range.

Since the intensity of the inspection radar wave is proportional to the intensity of the radar wave transmitted from the transmitter 1, the waveguide 5
Even if the incident end 11 is arranged as shown in FIG. 1, it is possible to detect normality / abnormality in the detection area 7 by checking the intensity of the inspection radar wave. However, by adopting the arrangement as shown in FIG. 2, the intensity of the radar wave is detected at the boundary N of the detection area 7, and the normality / abnormality of the detection area 7 can be confirmed more directly.

FIG. 3 shows another example for confirming the detection area 7. The boundary N of the normal detection area 7 is shown by a solid line, and the incident end 11 of the waveguide 5 is located at the boundary N as in the example of FIG.
It is an arrangement that just takes over. When the detection area 7 is reduced and becomes as indicated by a dotted line M, the intensity of the radar wave incident on the incident end 11 decreases, so that it is detected that the detection area 7 has been reduced. Part Q at boundary N of detection area 7
Simulates side lobes found in ultrasonic radar sensors and the like. If the transmitted radar wave intensities of the side lobe and the detection area 7 are correlated, even if the side lobe Q is not included in the detection area 7 unlike the illustration, the transmitted radar wave in the side lobe is detected. It may be arranged to be introduced into the waveguide 5 as a radar wave for inspection.

By the way, the intensity of the radar wave reflected by the object 9 and received by the receiver 3 is generally much smaller than the intensity of the radar wave transmitted from the transmitter 1.
The receiver 3 has a threshold for detecting such a low-intensity reflected radar wave. On the other hand, the radar wave for inspection is
Since only the radar wave transmitted from the transmitter 1 is propagated, the intensity can be considered to be much higher than the intensity of the radar wave reflected from the object 9. Therefore, as described above, the detection area 7 is determined from the intensity of the inspection radar wave.
In order to know the abnormality of, it is necessary to use a plurality of different thresholds and use them at different times.

FIG. 4 shows an example in which an attenuator 13 is provided on a part or the entirety of the waveguide 5 as one method for saving such trouble. The attenuation unit 13 reduces the intensity of the radar wave when the radar wave passes. As means for reducing the intensity of the radar wave in the attenuation unit 13, for example, a part of the radar wave propagating from the left to the right in the drawing is reflected, a part is absorbed, or a part is separated. For example, there is a method of converting to a physical quantity. For example, in the case of a sound wave, a resonator, an elastic plate sound absorbing material, a porous material, or the like is used.

Further, a configuration may be adopted in which part or all of the waveguide 5 leaks a part of the propagating radar wave to the outside. For example, when a radar wave is a light wave and an optical fiber is used for the waveguide 5, the propagating light wave is not totally reflected by the inner surface of the optical fiber, but is partially leaked to the outside to reduce the radar wave intensity. Can be.

When the radar wave is an electromagnetic wave and a coaxial line is used for the waveguide 5, a leaky coaxial line can be used as the coaxial line. Further, it can also be realized by using a dielectric line or a waveguide. An antenna is usually attached to the entrance end 11 and the exit end 12, but the amount of attenuation can also be adjusted by the efficiency of the antenna.

FIG. 5 shows another example of the structure of the waveguide.
In the example shown in FIG. 5, the inspection radar wave is temporarily
From the exit end 15 of the waveguide 5 to the reflector 19, and the inspection radar wave reflected by the reflector 19 is again transmitted to the entrance end 1 of the waveguide 5.
7, and is transmitted. In this case, the intensity of the inspection radar wave can be adjusted by adjusting the reflectance of the reflector 19.

FIG. 6 shows still another example of the waveguide. As shown in FIG. 6, the intensity of the inspection radar wave can be adjusted by disposing the transmitting material 21 between the two waveguides 5 and 5 and adjusting the transmittance of the transmitting material 21.

The positions at which the reflector 19 and the transmissive member 21 are interposed are not limited to the positions described above. For example, a configuration in which the transmitted radar wave is reflected or transmitted to be incident on the waveguide 5 or a configuration in which the inspection radar wave emitted from the waveguide 5 is reflected or transmitted and propagated to the receiver 3. Is also good.

As described above, the intensity of the inspection radar wave incident on the receiver 3 is adjusted, and the intensity of the inspection radar wave is determined using the threshold value for determining the presence / absence of the object 9. It can be performed. That is, it is not necessary to provide another threshold value to know the abnormality of the detection area 7 from the intensity of the inspection reflector. Regarding the configuration, a case where a transmitter / receiver in which a transmitter and a receiver are combined is used will be described.

FIG. 7 illustrates the application of the waveguide 5 when using the transducer 10 in which the transmitter and the receiver are combined into one unit. Input end 11 and output end 12 of waveguide 5
Are facing the transducer 10. Waveguide 5
Can be installed at an arbitrary position within a range where a radar wave having a predetermined intensity or more can reach, and the emission end 12 of the waveguide 5 is arranged so as to propagate the inspection radar wave to the transducer 10. The propagation delay time T from the input end 11 to the output end 12 is determined from the length L of the waveguide 5 and the propagation velocity v. Therefore,
Also in the case of the embodiment shown in FIG. 7, it can be installed according to the directivity regardless of the dead distance, and the reception delay time of the inspection radar wave can be set arbitrarily. It is clear that the arrangements shown in FIGS. 2 to 6 can be applied to the arrangement shown in FIG.

FIG. 8 illustrates another application of the waveguide 5 to the transducer 10 in which the transmitter and the receiver are combined as one unit. One end of the waveguide 5 is a reflection surface 13. The radar wave enters from one end 11 of the waveguide 5, propagates through the waveguide 5, is reflected by the reflection surface 13, propagates in the opposite direction, and exits from the one end 11 of the waveguide 5. That is, the input end and the output end are at the same end 11. The propagation delay time T from incidence to emission is approximately given by T = 2 L / v, where L is the length of the waveguide 5 and v is the propagation velocity. Obviously, even with this arrangement, the application of FIGS. The intensity of the inspection radar wave can also be adjusted by adjusting the reflectance of the reflecting surface 13.

FIG. 9 illustrates the application of the waveguide 5 to an object detection device that scans the detection area 7 and detects the detection object 9 while changing the direction of the transmission radar wave every moment. In the illustrated example, the radar wave transmitted from the transmitter 1 is transmitted to the scan mirror 2.
3 (galvanometer mirror), scans the inside of the detection space 7, and receives a reflected radar wave from the detection object 9 existing in the detection area 7 by the receiver 3, and 9 is detected. The scan mirror 23 has a rotation axis 25 and is driven to rotate in the direction of the arrow MZ1 or MZ2. Such an object detecting device is disclosed, for example, in Japanese Patent Application No. 9-305932.

The incident end 11 of the waveguide 5 can be installed at an arbitrary position within a range where a radar wave having a predetermined intensity or more reaches. The emitting end 12 of the waveguide 5 propagates the inspection radar wave to the receiver 3. It is arranged to be. Obviously, the arrangement shown in FIGS. 2 and 3 can be applied to this arrangement. In particular, if the incident end 11 is arranged at the end of a range where a radar wave having a predetermined intensity or more reaches, the normality of the scanning range can be confirmed. That is, when the scanning range becomes narrow, the radar wave does not reach the incident end 11 or the intensity decreases. By detecting this, it is possible to detect that the detection area 7 is reduced. In addition, it can be installed according to the directivity regardless of the dead distance, and the reception delay time of the inspection radar wave can be set arbitrarily.

FIG. 10 illustrates the application of the waveguide 5 to a phased array radar device. A desired azimuth radar wave is transmitted by shifting the phases of the radar waves of the plurality of n transmitters 110 to 1n0. The waveguide 5 can be applied to this device as in FIG.

FIG. 11 shows a scanning type configuration in which the transmitter 1
An example of application to an object detection device having a configuration in which a radar wave transmitted from an object and a reflected radar wave from the detection target 9 to the receiver 3 pass through substantially the same path will be described. The incident end 11 of the waveguide 5 can be installed at an arbitrary position within a range where a radar wave having a predetermined intensity or more reaches, and the emitting end 12 of the waveguide 5 is transmitted to the receiver 3 so as to propagate the inspection radar wave to the receiver 3. Be placed. Also in the case of this embodiment, it is possible to set up according to the directivity regardless of the dead distance, and it is possible to arbitrarily set the reception delay time of the inspection radar wave.

FIG. 12 shows a scanning type configuration in which the transmitter 1
An example of application to an object detection device having a configuration in which a radar wave transmitted from a receiver and a reflected radar wave from the detection target 9 to the receiver 3 pass through substantially the same path will be described. As in FIG. 5, one end of the waveguide 5 is used as a reflection surface, and the other end is used as the input end 11 and the output end 1.
Let it be 2. Also in the case of this embodiment, it is possible to set up according to the directivity regardless of the dead distance, and it is possible to arbitrarily set the reception delay time of the inspection radar wave.

Although the waveguide 5 is provided outside the so-called horn in the above description, the configuration is not necessarily limited to this. For example, as shown in FIG. 13, the end 11 can be provided inside the horn 27. Further, as shown in FIG. 14, a structure may be adopted in which the incident end 11 is provided in a part of the horn 27, and the waveguide 5 is connected to the incident end 11. 13 and 14, reference numeral 29 indicates a transducer.

As a method for fixing the waveguide 5, a method that does not disturb the inspection radar wave propagating inside is adopted. For example, when the radar wave is an ultrasonic wave, as the waveguide 5,
If a hollow tube is used and ultrasonic leakage can be ignored,
The fixing method is relatively free. On the other hand, if ultrasonic leakage from the surface cannot be ignored, for example, by using a solid pipe, it may be fixed via an acoustic insulator (cork in the case of ultrasonic waves).

FIGS. 15 and 16 show an example in which an open space is used as the waveguide 5. These examples are
It teaches that the waveguide 5 does not necessarily have to be closed. In the example of FIG. 15, a part of the radar wave transmitted from the transmitter 1 is reflected by the reflector 31 so that the spatial waveguide 5
To propagate in the direction where the receiver 3 is located. The inspection radar wave that has passed through the spatial waveguide 5 is reflected by the reflector 33 and enters the receiver 3.

In the example shown in FIG. 16, a part of the radar wave transmitted from the transducer 10 is reflected by the reflector 31 as an inspection radar wave, and is guided to the reflector 35 through the spatial waveguide 5. The inspection radar wave is reflected in the reverse direction by the reflector 35, passes through the spatial waveguide 5 in the reverse direction, and is incident on the transducer 10 by the reflector 31.

FIG. 17 is a block diagram showing a configuration example of the object detection device according to the present invention. The illustrated object detection device includes a transmitter 1, a receiver 3, a reception signal processing unit 6, and a transmission unit 8.

The transmitting section 8 includes a transmitting circuit 37 and a timing signal generating circuit 38. The transmission circuit 37 receives the signal S1 from the timing signal generation circuit 38 and generates a transmission signal, and the radar wave transmitted from the transmitter 1 is transmitted to space based on the signal.

The reception signal processing section 6 includes a reception circuit 39 and an operation confirmation determination circuit 40. The receiving circuit 39 outputs a signal R1 indicating presence of reception based on the signal supplied from the receiver 3.
Generate

The operation check judging circuit 40 includes a non-existence judging circuit 41, a check circuit 43, and an AND operation circuit 45. The non-existence determination circuit 41 receives at least the signal S1 indicating the transmission time and the signal R1 indicating reception, and determines the presence or absence of the detection target 9 from the presence or absence of a reflected radar wave within a predetermined period after transmission. . When there is no detected object 9,
A signal Ab having a logical value 1 is generated, and a signal Ab having a logical value 0 is generated when the detection target 9 is present.

The confirmation circuit 43 outputs a signal indicating the time of transmission and a signal R indicating the presence of reception, which is generated based on the reflected radar wave.
1 is received, the transmission time is compared with the reception time of the test radar wave, and when the difference between the two times is within a predetermined range, the signal is regarded as normal and a signal Z of logical value 1 is generated, and the signal Z is out of the predetermined range. Sometimes, a signal Z having a logical value 0 is generated as an abnormality.

The AND operation circuit 45 includes the absence judgment circuit 4
A logical AND operation of the signal Ab output from 1 and the signal Z output from the check circuit 43 is performed, and a signal Y is output as a result of the logical AND operation. The signal Y has a logical value of 1 when normality has been confirmed and the detected object 9 is absent.

FIG. 18 is an electric circuit showing a specific circuit configuration of the confirmation circuit 43. The confirmation circuit 43 indicated by a large dotted line includes a time window circuit 51, a coincidence confirmation circuit 53, and a storage circuit 55. The timing signal generation circuit 38 generates a signal S1 having a logical value 1 at every predetermined cycle. Signal S1
Is transmitted to the transmission circuit 37, and the signal S1 has the logical value 1
At this time, the transmitter 1 transmits the transmitted radar wave for a predetermined period.

When the receiver 3 receives a reflected radar wave having a predetermined intensity or more, a signal R1 having a logical value 1 is generated during that period. When not received, signal R1 has a logical value of 0
Becomes

The signal S10 indicating the transmission time is sent to the confirmation circuit 43
Is also entered. Here, the signal S10 is an inverted signal of the signal S1. In the following description, the receiver 3 is used for the reflected radar wave from the object 9 and the inspection radar wave.
Describes that the intensity is determined by the same threshold value, but the intensity may be determined by different threshold values.

The time window circuit 51 outputs a signal S indicating the transmission time.
10, a signal S2 having a logical value of 1 is generated for a predetermined period after a predetermined time has elapsed after the signal S10 has changed to the logical value of 1.

The illustrated time window circuit 51 includes an on-delay circuit 57 and a pulse generation circuit 59.
The diode indication added to the output side of the on-delay circuit 57 indicates a rectifier circuit. Signal S10 of logical value 1
Is input to the ON-delay circuit 57 of the time window circuit 51. The on-delay circuit 57 has an on-delay time τ1
And the state of the logical value 1 of the signal S10 is ON / OFF.
The signal Sa1 having the logical value 1 is generated from the time when the delay time τ1 or more continues until the signal S10 becomes the logical value 0. The signal Sa1 is input to the pulse generation circuit 59.

The pulse generation circuit 59 outputs a signal S having a logical value of 1.
For a predetermined period after receiving a1, a signal S2 having a logical value of 1 is generated. The illustrated pulse generation circuit 59 includes a photocoupler composed of a combination of a light emitting diode D12 and a phototransistor Q11, and a level verification circuit 61. The resistor R11 is connected to the light emitting diode D12, and the resistor R12 is connected to the emitter of the phototransistor Q11. Phototransistor Q11
Is connected to the resistor R12 by a capacitor C
The signal is led to the input terminal of the level test circuit 61 via the line 12. The input terminal of the level verification circuit 61 has a power supply voltage Vc
c is supplied via a diode D13.

Signal S2 output from time window circuit 51
Is input to the AND circuit 65 in the coincidence confirmation circuit 53 together with the signal R1. The output S3 of the AND circuit 65 is S2
If R1 and R1 do not simultaneously take the logical value 1, the logical value 1 will not be obtained. The on-delay time τ1 and the pulse generation period are set in advance so that the time when the signal S2 becomes the logical value 1 is the time when the inspection radar wave is received in a normal state. Therefore, if the test radar wave is received at the time to be received, a signal S3 having a logical value of 1 is generated, and if not received, the signal S3 has a logical value of O.

In the illustrated embodiment, the coincidence check circuit 53 includes a capacitor C13 and a diode D14,
1 is supplied to one of the input terminals of the AND circuit 65 via the capacitor C13. The power supply voltage Vcc is supplied to one of the input terminals of the AND circuit 65 via the diode D14.

The signal S3 is transmitted as a trigger signal T of the self-holding circuit 67 of the storage circuit 55. Self-holding circuit 6
As the hold signal H of 7, the signal S10 is input. The hold signal H has a logical value of 1 after the transmission of the radar wave until the transmission time of the next radar wave. If the signal S3 is normal after a predetermined period from the transmission, the signal S3 becomes the logical value 1
Therefore, the trigger signal T has a logical value of 1. While the hold signal H keeps the logical value 1 from that point, the signal Sc1 of the logical value 1 is generated. The signal Sc1 is input to the off-delay circuit 69.

The off-delay circuit 69 generates a signal Z having a logical value 1 when the signal Sc1 having a logical value 1 is inputted. Even if the signal Sc1 has a logical value O, the off-delay circuit 69 has a predetermined off-delay time η1. During this time, the signal Z is kept at the logical value 1. When the state in which the signal Sc1 has the logical value 0 continues beyond the off-delay time η1, the signal Z becomes the logical value O.

Accordingly, if the signal R1 of the logical value 1 is not generated at a predetermined time because the inspection radar wave is not received or the like, the signal S3 does not become the logical value 1, so even if the hold signal H becomes the logical value 1, , The signal Sc1 of the logical value 1 is not generated. Since the off-delay time η1 is set longer than the on-delay time τ1, if normal, the signal Z1 of the logical value 1 is continuously generated, but the signal S10
Is set to be shorter than the cycle at which the logical value becomes 0, and if the signal Sc1 of the logical value 1 is not normally generated even once, the signal Z of the logical value 0 is generated and the abnormality is notified.

In FIG. 18, off-delay circuit 69
Includes a diode D15, a capacitor C14, and a level test circuit 71. The signal Sc1 output from the self-holding circuit 67 is supplied to the level test circuit 71 through the diode D15. The input terminal of the level verification circuit 71 is connected to a capacitor C14 having the other end connected to the power supply Vcc.
Is connected. Reference numerals 49 and 63 indicate interface circuits. The interface circuits 49 and 63 have capacitors C11 and C13 and diodes D11 and D14.

FIG. 19 is a block diagram showing another embodiment of the object detecting apparatus according to the present invention. In the figure, the same components as those shown in FIG. 17 are denoted by the same reference numerals. The illustrated object detection device includes, as characteristic portions, a scanning circuit 73 and a scan mirror 23, and a radar wave is transmitted so as to scan the detection area 7 and receives a reflected radar wave from the detection object 9. Detected object 9 is detected based on.

The scanning circuit 73 causes the radar wave to be transmitted so as to scan into space. The receiver 3 receives the reflected radar wave, converts the reflected radar wave into an electric signal, and supplies the electric signal to the receiving circuit 39. The receiving circuit 39 generates a signal R1 indicating that there is reception based on the signal.

The non-existence determination circuit 41 receives at least the signal S1 indicating the direction of transmission and the signal R1 indicating the presence of reception, and determines whether the object 9 is detected based on the presence or absence of a reflected radar wave in a predetermined direction.
Is determined. When there is no detected object 9, a signal Ab having a logical value of 1 is generated, and when there is an detected object 9, a signal Ab having a logical value of 0 is generated. Note that in FIG.
The direction corresponds to the predetermined direction.

The confirmation circuit 43 receives at least a signal indicating the transmission azimuth of the radar wave and a signal indicating the presence of reception generated based on the reflected radar wave, compares the transmission azimuth with the reception presence / absence of the inspection radar wave, and A signal Z having a logical value of 1 is generated on the assumption that reception is normal in the bearing. Further, a signal Z having a logical value of 0 is generated with the absence of reception as an abnormality.

The AND operation circuit 45 outputs the signal Ab and the signal Z
And outputs a signal Y as a result of the operation. When the normality is confirmed and the detected object 9 is absent, the signal Y has the logical value 1.

FIG. 20 shows a specific electric circuit of the confirmation circuit 43 which can be employed in the object detecting device shown in FIG. The illustrated confirmation circuit 43 includes an azimuth signal generation circuit 75.
, A coincidence confirmation circuit 77 and a storage circuit 79. The azimuth signal generation circuit 75 converts the azimuth signal S1 from the azimuth signal S1 to the directional signal S2 indicating that the inspection radar wave is to be received.
Generate

The scanning circuit 73 outputs a logical value 0 every predetermined period.
Is generated. The signal S1 is the scan mirror 23
It is assumed that the scan mirror 23 is directed to a specific direction when the signal S1 has the logical value 0. When a reflected radar wave having a predetermined intensity or more is received by the receiver 3, the receiving circuit 39 generates a signal R1 having a logical value 1 during that period. When a reflected radar wave having a predetermined intensity or more is not received, the signal R1 has a logical value O.

The azimuth signal generation circuit 75 receives the signal S1 and generates the signal S2 having a logical value of 1 when the scan mirror 23 is oriented in the azimuth at which the inspection radar wave is received. Here, it is assumed that the drive frequency of the scan mirror 23 is determined, and the scan mirror 23 is oriented in a direction in which the inspection radar wave is received a predetermined time after the signal S1 becomes the logical value 1. Specifically, the time window circuit 51 shown in FIG. 9 can be used. By adjusting the on-delay time τ1 and the pulse generation period, the signal S2 having the logical value 1 can be generated for a predetermined period.

The signal S2 is input to the coincidence check circuit 77 together with the signal R1. The coincidence check circuit 77 includes an inverter circuit 85, an OR circuit 87, and a level test circuit 89.

The inverter circuit 85 includes a light emitting diode D
22 and a phototransistor composed of a phototransistor Q21. For the light emitting diode D22, the signal S2 output from the azimuth signal generation circuit 75 is:
It is supplied via a resistor R21. Phototransistor Q
One end of a capacitor C22 is connected to the collector of the capacitor 21, and an inverted signal S20 of the signal S2 is output from the other end of the capacitor C22. The operating power supply Vcc is supplied to the collector of the phototransistor Q21 through the resistor R22. A diode D is connected to the other end of the capacitor C22.
An operation power supply Vcc is supplied through 23.

The OR circuit 87 is a wired circuit connecting the cathode of the diode D25 and the cathode of the diode D26. Configured as OR. OR circuit 87
, The inverted signal S20 output from the inverter 85 constituting the coincidence confirmation circuit 77 and the signal R1 output from the receiving circuit 39 are input. If the operation of the detection system is normal, the signal S2 and the signal R1 become the logical value 1 or the logical value O almost simultaneously. Therefore, if normal, the signal S20
And the signal R1 change complementarily. That is, (S
20, R1) = (1, O) or (O, 1), so that the logical sum of the signal S20 and the signal R1 always becomes the logical value 1.

The level test circuit 89 has at least a lower threshold value for distinguishing the output of the logical value 1 and the logical value O of the logical sum circuit 87. When the output of the OR circuit 87 has the logical value 1, the signal S3 having the logical value 1 is output. If the test radar wave is not received in the direction to be received, the signal S20 and the signal R1 have a logical value of 0, so that the signal S3 output from the level test circuit 89 has a logical value of 0.

The storage circuit 79 receives the signal S3, and when the signal S3 has the logical value 1, generates the signal Z of the logical value 1.
The storage circuit 79 has an off-delay time η2,
Even if the signal S3 has the logical value O, the off-delay time η
Until 2 has elapsed, the generation of the signal Z having the logical value 1 is continued. The off delay time η2 is determined by the signal S20 and the signal R1.
This is provided to allow a slight temporal error.
If the logical 0 signal S3 continues beyond the off-delay time η2, the signal Z becomes logical 0. Therefore, if the signal R1 having the logical value 1 is not generated at a predetermined time because the inspection radar wave is not received, the signal S3 has the logical value O, but the signal S3 has the logical value 0 in the off delay time η1. Since the period is set shorter than the period, the signal Z of the logical value 0 is set.
Occurs and an abnormality is reported.

Although not shown, even in the phased array radar apparatus as shown in FIG. 10, a signal indicating the azimuth of transmission of the radar wave is used as a signal S1 as a confirmation circuit 43.
, The object detection performance can be similarly confirmed.

FIG. 21 is a block diagram showing still another embodiment of the object detecting apparatus according to the present invention. In the drawings, the same components as those shown in the drawings previously described are denoted by the same reference numerals. In the illustrated object detection device, the transmitter 1 is constituted by a laser diode for transmitting a light wave. The receiver 3 includes a light receiving element that receives a light wave and converts the light wave into an electric signal. The transmitter 1 composed of a laser diode is driven by the transmitter 8. The waveguide 5 receives a part of the radar wave, which is the light wave transmitted to the detection area 7 from one end side, and passes the incident radar wave. The inspection radar wave that has passed through the waveguide 5 is supplied to the receiver 3 that is a light receiving element.

The scan mirror 23 is disclosed in
A known semiconductor galvanometer mirror such as 218857 can be used. The scan mirror 23 is rotated by the drive circuit 91 about the rotation shaft 25 in the directions of arrows MZ1 and MZ2. The rotation shift of the scan mirror 23 is detected by the rotation shift detection unit 93. In Japanese Patent Application Laid-Open No. Hei 7-218857, two detection coils are provided for the purpose of detecting the displacement angle of the movable plate. The detection coil is arranged so as to be capable of electromagnetically coupling with a plane coil provided on the movable plate. Due to the displacement of the movable plate,
Mutual inductance between the planar coil and each of the two detection coils changes.

The rotation shift detecting means 93 indicates a coil. The rotation displacement detection circuit 95 detects the displacement angle of the fluctuating plate, for example, based on a voltage signal output based on the mutual inductance. The output signal is supplied to the reception signal processing unit 6 as a signal indicating the direction. The configuration and function of the received signal processing unit 6 have already been described, and thus are omitted here. In the case of this embodiment, the same operation and effect as those of the above-described embodiment can be obtained.

When the level test circuit and AND circuit used in FIGS. 18 and 20 are configured as fail-safe elements, US Pat. Nos. 5,345,138, 4,661,880, and US Pat. The fail-safe window comparator / AND gate disclosed in Japanese Patent No. 5,027,114 or the like can be used. In addition, regarding the circuit, its operation, and fail-safe characteristics, see the IEEJ Transactions (Trans.IE
E of Japan) Vo1, 109-c, No. 9, Sep. 1989 (one configuration method of an interlock system using a fail-safe logic element having a window characteristic), and “App1ication of W
indow Comparator to Majority Operation "Proc.of 19
th International Symp.on Mu1tip1e-Va1ued Logic, IEE
It is also described in documents such as E Computer Society (May 1989). In addition, as an on-delay circuit, an international publication WO
No. 94/23303, International Publication W094 / 23496, Tokuhei 1-
A fail-safe on-delay circuit known in JP 23006, JP-A-7-22932 and JP-A-9-627714 can be used. International Patent Publication WO94
A fail-safe circuit known in, for example, Japanese Patent Application Laid-Open No. 23303/1990 and International Publication WO 94/23496 can be used. The fail-safe property of the rectifier circuit is described in detail in, for example, International Publication WO93 / 23772. By using such fail-safe elements, it is possible to configure a highly secure confirmation circuit that can detect transmission / reception errors in a fail-safe manner.

[0092]

As described above, according to the present invention, the following effects can be obtained. (A) It is possible to provide an operation check device that can be installed according to directivity regardless of a dead distance, and an object detection device having the operation check device. (B) It is possible to provide an operation check device capable of simply and reliably eliminating the influence of reverberation, and an object detection device having the operation check device. (C) It is possible to provide an operation check device capable of easily and surely checking the range of the space detection region, and an object detection device having the operation check device. (D) Checking the intensity of the transmitted radar wave easily and
It is possible to provide an operation check device that can surely perform the operation and an object detection device having the operation check device.

[Brief description of the drawings]

FIG. 1 is a diagram showing the concept of an object detection device according to the present invention.

FIG. 2 is a diagram showing an example for confirming a range of a detection area in the object detection device according to the present invention.

FIG. 3 is a diagram showing another example for confirming the range of a detection area in the object detection device according to the present invention.

FIG. 4 is a diagram illustrating an example in which an attenuation unit is provided in a waveguide used in the object detection device according to the present invention.

FIG. 5 is a diagram showing another example of the waveguide used in the object detection device according to the present invention.

FIG. 6 is a diagram showing still another example of the waveguide used in the object detection device according to the present invention.

FIG. 7 is a diagram illustrating an application example of a waveguide when a transmitter / receiver in which a transmitter and a receiver are combined into one unit is used in the object detection device according to the present invention.

FIG. 8 is a diagram showing another application example of the waveguide in the case of using the transmitter / receiver in which the transmitter and the receiver are combined into one unit in the object detection device according to the present invention.

FIG. 9 is a diagram illustrating an example of application of a waveguide to an object detection device that scans a detection area and detects an object by changing the direction of a transmission radar wave in the object detection device according to the present invention. is there.

FIG. 10 is a diagram showing an application example of a waveguide to a phased array radar device in the object detection device according to the present invention.

FIG. 11 is a diagram showing a waveguide of an object detection device of a scanning type in which a radar wave transmitted from a transmitter and a reflected radar wave from a detection target to a receiver pass through substantially the same path. It is a figure showing an example of application.

FIG. 12 is an application of a waveguide in an object detection apparatus which is a scanning type and has a configuration in which a radar wave transmitted from a transmitter and a reflected radar wave from a detection target to a receiver pass through substantially the same path. It is a figure showing an example.

FIG. 13 is a diagram showing an example of an arrangement of waveguides with respect to a horn constituting a transmitter, a receiver or a transmitter / receiver in the object detection device according to the present invention.

FIG. 14 is a diagram showing another example of the arrangement of the waveguide with respect to the horn constituting the transmitter, the receiver or the transmitter / receiver in the object detection device according to the present invention.

FIG. 15 is a diagram showing an example in which an open space is used as a waveguide in the object detection device according to the present invention.

FIG. 16 is a diagram showing another example in which an open space is used as a waveguide in the object detection device according to the present invention.

FIG. 17 is a block diagram illustrating a configuration example of an object detection device according to the present invention.

18 is an electric circuit showing a specific circuit configuration of a confirmation circuit that can be employed in the object detection device shown in FIG.

FIG. 19 is a block diagram showing another embodiment of the object detection device according to the present invention.

20 is a specific electric circuit of a confirmation circuit that can be employed in the object detection device shown in FIG.

FIG. 21 is a block diagram showing another embodiment of the object detection device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transmitter 3 Receiver 5 Waveguide 6 Received signal processor 8 Transmitter

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Koichi Hogura 1-13-8 Kamikizaki, Urawa-shi, Saitama Japan Signaling Corporation Yino Works F-term (reference) 5J070 AA14 AB01 AC02 AC13 AD02 AD10 AE01 AE07 AE20 AF03 AG07 AH04 AH14 AH31 AH33 AH34 AH50 AJ13 AK03 AK06 AK32

Claims (10)

[Claims] 1. An object detection device including a transmitter, a waveguide, a receiver, and a reception signal processing unit, wherein the transmitter transmits a radar wave toward a detection area, The waveguide is configured to receive a part of the radar wave transmitted to the detection area from one end side and pass the incident radar wave, and the receiver includes: a reflected radar wave of the radar wave; And receiving a radar wave passing through the waveguide, wherein the reception signal processing unit determines presence / absence of an object in the detection area from a reception signal of the reflected radar wave supplied from the receiver. An object detection device for detecting and confirming normal operation of a detection system from a received signal of the radar wave passing through the waveguide. 2. The object detection device according to claim 1, wherein the waveguide has such a degree that the passing radar wave can be distinguished from reverberation caused by the radar wave transmitted toward the detection area. An object detection device that gives a delay time. 3. The object detection device according to claim 1, wherein the waveguide includes a unit for adjusting a speed of the radar wave passing therethrough. 4. The object detection apparatus according to claim 1, wherein the waveguide includes a unit for adjusting an intensity of the radar wave passing therethrough. 5. The object detection device according to claim 1, wherein the transmitter and the receiver are configured by one transceiver, and the waveguide is An object detection device that causes a radar wave transmitted from the transducer to enter from one end side and emits the incident radar wave from the same end toward the transducer. 6. The object detection device according to claim 1, wherein the waveguide is an object on which the radar wave is incident near a boundary between the detection area and a non-detection area. Detection device. 7. The object detection device according to claim 1, wherein the reception signal processing unit is configured to transmit the radar wave after a lapse of a predetermined time from a time when the radar wave is transmitted. An object detection device that determines that the function is normal when a signal corresponding to a radar wave that has passed through is received. 8. The object detection device according to claim 1, wherein the reception signal processing unit generates a signal corresponding to a radar wave passing through the waveguide in a predetermined transmission direction. When received,
An object detection device that determines that the function is normal. 9. The object detection device according to claim 1, wherein the reception signal processing unit has a signal corresponding to a radar wave passing through the waveguide having a value equal to or greater than a predetermined value. When the object detection device determines that the function is normal. 10. A device for confirming normal operation of an object detection device, comprising a waveguide and a reception signal processing unit, wherein the object detection device transmits a radar wave to a detection area by a transmitter. And a device that detects an object when a reflected radar wave is received by a receiver, wherein the waveguide receives a part of a radar wave transmitted from one end side to a detection area and receives the reflected radar wave. Passing the wave and supplying the signal to the receiver, the reception signal processing unit is supplied with a reception signal of the radar wave received by the receiver through the waveguide,
An operation check device that processes the received signal to check whether the object detection device operates normally.