JP6364960B2 - Radio wave sensor, detection method and detection program - Google Patents

Description

  The present invention relates to a radio wave sensor, a detection method, and a detection program, and more particularly, to a radio wave sensor, a detection method, and a detection program that detect an object using radio waves.

  Japanese Patent Laying-Open No. 2012-247215 (Patent Document 1) discloses an object identification device that is mounted on a vehicle and identifies the type of an object that exists around the vehicle. The object identification device is an object including information on a reflection intensity and a distance to an object around the vehicle obtained by irradiating the vehicle with a sound wave or an electromagnetic wave and detecting the sound wave or a reflected wave of the electromagnetic wave. Information and information on the height of the object obtained by image processing are acquired. The object identification device corrects the reflection intensity according to the height of the object and the distance to the object. Then, the object identification device identifies the type of the object according to the corrected reflection intensity.

Takayuki Inaba, Tetsuro Kirimoto, “Automotive Millimeter Wave Radar”, Automotive Technology, February 2010, Vol. 64, No. 2, p. 74-79 Koji Yoichi, 2 others, “Application of expanding millimeter-wave technology”, [online], [Search April 9, 2014], Internet <URL: http: // www. spc. co. jp / spc / pdf / giho21_09. pdf> Junmi Jimbo, 2 others, “Examination of application of dual frequency ICW radar to safe driving support system”, Proceedings of the 2013 IEICE General Conference Proceedings of 2013 General Conference, March 2013, Lecture Number: B- 2-23, P265

JP 2012-247215 A

  However, for example, when the object identification device described in Patent Document 1 is installed in a place where the power that can be supplied is limited, if the power consumption in the object identification device exceeds the limit value, the object identification device There are times when it becomes difficult to operate the system stably. For this reason, there is a need for a radio wave sensor such as an object identification device that can operate with low power consumption.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a radio wave sensor, a detection method, and a detection program capable of correctly detecting an object while suppressing power consumption. is there.

  (1) In order to solve the above-described problem, a radio wave sensor according to an aspect of the present invention includes a transmission unit that transmits radio waves to a target area, a reception unit that receives radio waves from the target area, and the reception unit. A detection unit that performs detection processing for detecting an object in the target area based on the received radio wave, and a control unit that performs control to change an execution interval of the detection processing based on a result of the detection processing With.

  (13) In order to solve the above-described problem, a detection method according to an aspect of the present invention is a detection method in a radio wave sensor, and includes a step of transmitting radio waves to a target area and receiving radio waves from the target area. A step of performing detection processing for detecting an object in the target area based on the received radio wave, and a step of performing control for changing an execution interval of the detection processing based on a result of the detection processing Including.

  (14) In order to solve the above problem, a detection program according to an aspect of the present invention is a detection program used in a radio wave sensor that transmits radio waves to a target area and receives radio waves from the target area. A step of performing detection processing for detecting an object in the target area based on the received radio wave, and a step of performing control for changing an execution interval of the detection processing based on a result of the detection processing. Is a program for executing

  The present invention can be realized not only as a radio wave sensor including such a characteristic processing unit, but also as a semiconductor integrated circuit that realizes part or all of the radio wave sensor, or as a system including the radio wave sensor. You can do it.

  According to the present invention, it is possible to correctly detect an object while suppressing power consumption.

FIG. 1 is a diagram showing a configuration of a signal control system according to the first embodiment of the present invention. FIG. 2 is a diagram showing a configuration of the radio wave sensor in the signal control system according to the first embodiment of the present invention. FIG. 3 is a diagram showing a configuration of a control unit in the radio wave sensor according to the first embodiment of the present invention. FIG. 4 is a diagram illustrating a configuration of a transmission wave processing unit in the transmission unit according to the first embodiment of the present invention. FIG. 5 is a diagram showing an example of the change of the operation mode by the radio wave sensor according to the first embodiment of the present invention. FIG. 6 is a diagram showing an example of the change of the operation mode by the radio wave sensor according to the first embodiment of the present invention. FIG. 7 is a diagram illustrating an example of a normal target area and an enlargement target area in which the radio wave sensor according to the first embodiment of the present invention can detect a target object. FIG. 8 is a diagram illustrating a configuration of a reception wave processing unit in the reception unit according to the first embodiment of the present invention. FIG. 9 is a diagram illustrating an example of the arrangement of the transmission antenna, the reception antenna, and the object according to the first embodiment of the present invention. FIG. 10 is a diagram showing a configuration of a signal processing unit in the radio wave sensor according to the first embodiment of the present invention. FIG. 11 is a diagram illustrating a configuration of a detection unit in the radio wave sensor according to the first embodiment of the present invention. FIG. 12 is a diagram showing a configuration of a modification of the radio wave sensor according to the first embodiment of the present invention. FIG. 13 is a diagram showing a configuration of a control unit in a modification of the radio wave sensor according to the first embodiment of the present invention. FIG. 14 is a diagram illustrating an example of a change in the operation mode according to a modification of the radio wave sensor according to the first embodiment of the invention. FIG. 15 is a diagram illustrating an example of a change in operation mode according to a modification of the radio wave sensor according to the first embodiment of the invention. FIG. 16 is a diagram showing a configuration of a modified example of the radio wave sensor according to the first embodiment of the present invention. FIG. 17 is a diagram illustrating a configuration of a control unit in a modification of the radio wave sensor according to the first embodiment of the invention. FIG. 18 is a diagram illustrating an example of a change in operation mode according to a modification of the radio wave sensor according to the first embodiment of the invention. FIG. 19 is a diagram illustrating an example of the change of the operation mode according to the modification of the radio wave sensor according to the first embodiment of the invention. FIG. 20 is a diagram illustrating an example of the directivity direction of the variable tilt transmission antenna in the modification example of the radio wave sensor according to the first embodiment of the invention. FIG. 21 is a flowchart defining an operation procedure when the radio wave sensor according to the first embodiment of the present invention detects an object in a target area according to an operation mode. FIG. 22 is a flowchart defining an operation procedure when the radio wave sensor according to the first embodiment of the present invention detects an object in the enlargement target area in the enlargement detection mode. FIG. 23 is a flowchart defining an operation procedure when the radio wave sensor according to the first embodiment of the present invention detects an object in the normal target area in the normal detection mode. FIG. 24 is a diagram showing a configuration of a radio wave sensor according to the second embodiment of the present invention. FIG. 25 is a diagram illustrating a configuration of a transmission wave processing unit in the transmission unit according to the second embodiment of the present invention. FIG. 26 is a diagram illustrating an example of the change of the operation mode by the radio wave sensor according to the second embodiment of the present invention. FIG. 27 is a diagram illustrating an example of the change of the operation mode by the radio wave sensor according to the second embodiment of the present invention. FIG. 28 is a diagram illustrating an example of a pulse signal generated by the transmission unit and the reception unit according to the second embodiment of the present invention. FIG. 29 is a diagram illustrating a configuration of a reception wave processing unit in the reception unit according to the second embodiment of the present invention. FIG. 30 is a diagram illustrating a configuration of a detection unit in the radio wave sensor according to the second embodiment of the present invention. FIG. 31 is a diagram showing a configuration of a modified example of the radio wave sensor according to the second embodiment of the present invention. FIG. 32 is a diagram illustrating an example of a change in operation mode according to a modification of the radio wave sensor according to the second embodiment of the present invention. FIG. 33 is a diagram illustrating an example of a change in operation mode according to a modification of the radio wave sensor according to the second embodiment of the present invention. FIG. 34 is a diagram showing a configuration of a modification of the radio wave sensor according to the second embodiment of the present invention. FIG. 35 is a diagram illustrating an example of operation mode change according to a modification of the radio wave sensor according to the second embodiment of the present invention. FIG. 36 is a diagram illustrating an example of operation mode change according to a modification of the radio wave sensor according to the second embodiment of the invention.

  First, the contents of the embodiment of the present invention will be listed and described.

  (1) A radio wave sensor according to an embodiment of the present invention is based on a transmitter that transmits radio waves to a target area, a receiver that receives radio waves from the target area, and radio waves received by the receiver. A detection unit that performs detection processing for detecting an object in the target area, and a control unit that performs control to change an execution interval of the detection processing based on a result of the detection processing.

  With such a configuration, since the frequency of the detection process can be reduced within a range that does not adversely affect the result of the detection process, it is possible to correctly detect the object while suppressing power consumption by the detection process.

  (2) Preferably, the transmission unit continuously transmits radio waves in the first period, stops transmitting radio waves in the second period, and alternates between the first period and the second period. The control unit repeatedly changes the execution interval by changing the length of the second period based on the result of the detection process.

  As described above, the configuration in which the length of the second period with low power consumption is changed while maintaining the length of the first period is used to suppress power consumption while avoiding deterioration in accuracy of detection processing. Can do.

  (3) Preferably, the transmission unit repeatedly transmits a pulse radio wave that is a pulsed radio wave, and the control unit performs the execution by changing the transmission interval of the pulse radio wave based on the result of the detection process. Change the interval.

  As described above, with the configuration in which the transmission interval of the repeatedly transmitted pulse radio wave is changed according to the result of the detection process, it is possible to suppress power consumption while avoiding deterioration in the accuracy of the detection process.

  (4) Preferably, the control unit performs a determination as to whether or not the detection unit has transitioned from a state in which the object is not detected to a detected state, and performs the execution based on a result of the determination. The radio wave sensor according to any one of claims 1 to 3, wherein the interval is shortened.

  With such a configuration, when a target object exists in the target area, the temporal transition of the detection result of the target object can be acquired with high accuracy. Further, efficient detection processing can be performed by a configuration in which the frequency of detection processing is increased in a situation where high-frequency detection processing is required after an object is detected.

  (5) Preferably, the control unit makes a determination as to whether or not the detection unit has transitioned from a state in which the object has been detected to a state in which the object has not been detected, and performs the execution based on the determination result. Increase the interval.

  As described above, efficient detection processing can be performed by a configuration in which the frequency of detection processing is reduced in a situation where high-frequency detection processing is not required after an object is no longer detected.

  (6) Preferably, the said control part changes the range of the said target area according to whether the predetermined conditions including the conditions regarding the result of the said detection process are satisfy | filled.

  With such a configuration, the range of the target area can be changed to an appropriate range according to the result of the detection process.

  (7) More preferably, the control unit changes the range of the target area by changing the transmission power of the transmission unit.

  With such a configuration, the range of the target area can be changed without using a mechanical operation, so that the mechanism of a transmitting device such as an antenna can be simplified.

  (8) More preferably, the control unit changes the range of the target area by changing the directivity of the antenna in the transmission unit.

  With such a configuration, it is possible to extend the reach of radio waves without increasing the transmission power of radio waves, and thus it is possible to suppress an increase in power consumption that accompanies a change in the range of the target area.

  (9) More preferably, the said control part changes the range of the said target area by changing the direction of the antenna in the said transmission part.

  With such a configuration, the beam direction of radio waves can be changed by a simple method, and the range of the target area can be flexibly changed.

  (10) Preferably, the said control part changes the said execution interval by changing the stop period of the electric power supply to the circuit for performing the said detection process.

  In this way, by stopping the circuit for performing the detection process in a period when the detection process is not performed, it is possible to suppress power consumption while changing the execution interval of the detection process.

  (11) Preferably, the radio wave sensor further includes a battery, and the control unit performs control to change an execution interval of the detection process based on a remaining amount of the battery and a result of the detection process.

  As described above, the configuration in which the frequency of the detection process is changed according to the remaining amount of the battery makes it possible to correctly detect the object while extending the time until the remaining amount of the battery becomes zero. That is, the operation time of the radio wave sensor can be extended.

  (12) More preferably, the radio wave sensor further includes a battery, and the control unit makes a determination regarding the stop of the power supply based on a remaining amount of the battery.

  With such a configuration, the power consumption in the circuit can be changed according to the remaining amount of the battery, so that the time until the remaining amount of the battery becomes zero can be extended. That is, the operation time of the radio wave sensor can be extended.

  (13) A detection method according to an embodiment of the present invention is a detection method in a radio wave sensor, the step of transmitting radio waves to a target area, the step of receiving radio waves from the target area, and the received radio waves And a step of performing a detection process for detecting an object in the target area, and a step of performing a control for changing an execution interval of the detection process based on a result of the detection process.

  With such a configuration, since the frequency of the detection process can be reduced within a range that does not adversely affect the result of the detection process, it is possible to correctly detect the object while suppressing power consumption by the detection process.

  (14) A detection program according to an embodiment of the present invention is a detection program used in a radio wave sensor that transmits a radio wave to a target area and receives a radio wave from the target area. A program for executing a step of performing a detection process for detecting an object in the target area based on a result and a step of performing a control for changing an execution interval of the detection process based on a result of the detection process. is there.

  With such a configuration, since the frequency of the detection process can be reduced within a range that does not adversely affect the result of the detection process, it is possible to correctly detect the object while suppressing power consumption by the detection process.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated. Moreover, you may combine arbitrarily at least one part of embodiment described below.

<First Embodiment>
[Configuration and basic operation]
FIG. 1 is a diagram showing a configuration of a signal control system according to the first embodiment of the present invention.

  Referring to FIG. 1, the signal control system 201 includes a radio wave sensor 101, a signal control device 151, a pedestrian signal lamp 161, a power generation unit 121, and a battery B1. The signal control device 151 and the pedestrian signal lamp 161 in the signal control system 201 constitute a traffic signal device, and are installed, for example, in the vicinity of the main road Rd1.

  The radio wave sensor 101 functions as a detection sensor that detects the object Tgt in the normal target area An1 and the expansion target area Ae1. Hereinafter, each of the normal target area An1, the enlargement target area Ae1, and the later-described enlargement target area Ae2 is also referred to as a target area.

  The target area is an area set by a sensor installer who is an installer of the radio wave sensor 101, for example. Specifically, as shown in FIG. 1, the sensor installer sets, for example, a pedestrian Tgt2 in a pedestrian crossing PC1 located between sidewalks Pv1 and Pv2 installed with a main road Rd1 as an object Tgt. In this case, the area including the pedestrian crossing PC1 is set as the normal target area An1.

  Further, for example, when the pedestrian Tgt2 in the pedestrian crossing PC1 and the pedestrian Tgt2 located in the vicinity of the pedestrian crossing PC1 are set as the object Tgt, the sensor installer sets the following areas as the enlargement target areas Ae1 or Ae2.

  That is, the sensor installer, for example, is a part of the sidewalk Pv2 that is a part of the sidewalk adjacent to the pedestrian crossing PC1 and is opposite to the radio wave sensor 101 with respect to the main road Rd1, that is, the waiting area As, and the pedestrian crossing. The area including PC1 is set as the enlargement target area Ae1 or Ae2.

  For example, the sensor installer may set an area including a part of the pedestrian crossing PC1 as the target area. In addition, for example, when the radio wave sensor 101 is attached to an automobile, the sensor installer can target a predetermined range in front of the automobile when the pedestrian Tgt2 and the automobile Tgt1 positioned in front of the automobile are the target Tgt. Set as area.

  The power generation unit 121 is, for example, a solar power generation device. When receiving the sunlight, the power generation unit 121 generates power from the received solar energy, and outputs the generated power to the battery B1 via a power line (not shown). The power generation unit 121 may be a wind power generator, for example.

  Battery B1 stores the electric power received from power generation unit 121. The battery B1 supplies operating power for the radio wave sensor 101 based on the stored power.

  The radio wave sensor 101 is installed, for example, in the vicinity of the main road Rd1. Specifically, the radio wave sensor 101 is fixed to, for example, a support P1 installed near the main road Rd1.

  The radio wave sensor 101 operates using power received from the battery B1 via a power line (not shown). The radio wave sensor 101 may operate using, for example, power received from the system.

  The pedestrian signal lamp 161 and the signal control device 151 are fixed to, for example, the support P1. The radio wave sensor 101 and the signal control device 151 are connected by a signal line (not shown), for example. The signal control device 151 and the pedestrian signal lamp 161 are connected by a signal line (not shown), for example. The radio wave sensor 101 may be installed on the main road Rd1 or may be mounted on an automobile.

  The radio wave sensor 101 performs, for example, a detection process for detecting the object Tgt in the target area. More specifically, the radio wave sensor 101 transmits radio waves to a target area including the pedestrian crossing PC1 under the control of the signal control device 151, for example. The object Tgt is, for example, a pedestrian Tgt2. Note that the object Tgt may be, for example, the automobile Tgt1.

  The target object Tgt is located in the target area, for example, and reflects the radio wave transmitted from the radio wave sensor 101. For example, the radio wave sensor 101 receives a radio wave reflected by the object Tgt and intermittently performs a detection process of detecting the object Tgt in the target area based on the received radio wave. For example, the radio wave sensor 101 transmits a detection result, which is a result of the detection process, to the signal control device 151 and changes an execution interval of the detection process based on the detection result.

  Under the control of the signal control device 151, the pedestrian signal lamp 161 illuminates and displays “recommend” or “to rare” for the pedestrian Tgt2 crossing the pedestrian crossing PC1, for example.

  When the signal control device 151 receives the detection result from the radio wave sensor 101, the signal control device 151 controls the pedestrian signal lamp 161 based on the received detection result.

  For example, when the detection result indicates that the pedestrian Tgt2 has entered the standby area As, the signal control device 151 turns on “recommend” in the pedestrian signal lamp 161. Thereby, pedestrian Tgt2 can be preferentially passed.

  In addition, for example, when the remaining time for turning on “recommend” in the pedestrian signal lamp 161 is small, the signal control device 151 extends the remaining time when the pedestrian Tgt2 is detected in the target area. Note that the signal control device 151 may notify the pedestrian Tgt2 by voice that, for example, there is little remaining time to light “Recommend”.

  In addition, for example, when the signal control device 151 lights “Tare rare” in the pedestrian signal lamp 161, when the pedestrian Tgt2 is detected in the target area, the signal control device 151 informs the pedestrian Tgt2 that it is dangerous. Warning.

  Note that the signal control device 151 may provide a service to the automobile Tgt1 based on the detection result received from the radio wave sensor 101. Specifically, for example, when the detection result indicates that the pedestrian Tgt2 is detected in the target area, the signal control device 151 gives a warning to the automobile Tgt1 that attention should be paid to the pedestrian Tgt2 in the pedestrian crossing PC1.

[Configuration of radio wave sensor]
FIG. 2 is a diagram showing a configuration of the radio wave sensor in the signal control system according to the first embodiment of the present invention.

  With reference to FIG. 2, the radio wave sensor 101 includes a transmission unit 1, a reception unit 2, a signal processing unit 3, a detection unit 4, and a control unit 5. The transmission unit 1 includes a transmission wave processing unit 10 and a transmission antenna 11. The receiving unit 2 includes a received wave processing unit 12 and a receiving antenna 13. The transmission antenna 11 and the reception antenna 13 are not limited to the configuration provided in the radio wave sensor 101 but may be provided outside the radio wave sensor 101.

  FIG. 3 is a diagram showing a configuration of a control unit in the radio wave sensor according to the first embodiment of the present invention.

  Referring to FIG. 3, control unit 5 includes a power supply intermittent unit 80, an amplification factor control unit 81, a comprehensive determination unit 82, and a battery remaining amount measurement unit 83. The overall determination unit 82 includes a mode setting unit 84 and an execution interval setting unit 85.

  FIG. 4 is a diagram illustrating a configuration of a transmission wave processing unit in the transmission unit according to the first embodiment of the present invention.

  Referring to FIG. 4, transmission wave processing unit 10 includes a radio wave generation unit 31, a directional coupler 32, and a power amplifier 33. The radio wave generation unit 31 includes a frequency switching unit 35, a voltage generation unit 36, and a voltage controlled oscillator 37.

  2 to 4, the radio wave sensor 101 is described in, for example, Takayuki Inaba, Tetsuro Kirimoto, “Millimeter-wave radar for vehicle use”, Automotive Technology, February 2010, Vol. 64, No. 2, 74-79 (Non-Patent Document 1), or Koji Yoichi, and two others, “Application of Expanding Millimeter-Wave Technology”, [online], [Search April 9, 2014], Internet <URL: http: // / Www. spc. co. jp / spc / pdf / giho21_09. pdf> (Non-Patent Document 2), a detection process for detecting the target Tgt in the target area is performed in accordance with the two-frequency CW (Continuous Wave) method. Details of the detection process will be described later.

  The transmission wave processing unit 10 in the transmission unit 1 uses the electric power received from the battery B <b> 1 via the control unit 5, and transmits radio waves to the target area via the transmission antenna 11 according to control by the control unit 5. The reception wave processing unit 12 in the reception unit 2 receives a radio wave from the target area via the reception antenna 13.

  The detection unit 4 performs a detection process for detecting the object Tgt in the target area based on the radio wave received by the reception unit 2. The detection unit 4 outputs the result of the detection process to the control unit 5 and the signal control device 151.

  For example, the control unit 5 performs control for changing the execution interval of the detection process based on the result of the detection process received from the detection unit 4 and the remaining amount of the battery in the battery B1, specifically, transmission of radio waves. Change the length of the suspension period to stop.

  More specifically, the control unit 5 changes the execution interval, for example, by changing a stop period of power supply to the radio wave generation unit 31 and the power amplifier 33 in the transmission wave processing unit 10. The radio wave generator 31 and the power amplifier 33 correspond to, for example, a circuit for performing detection processing.

  The battery remaining amount measuring unit 83 in the control unit 5 shown in FIG. 3 measures the remaining amount of the battery B1, and outputs the remaining amount measurement result, which is a result of the measurement, to the comprehensive determining unit 82.

[Set execution interval]
FIG. 5 is a diagram showing an example of the change of the operation mode by the radio wave sensor according to the first embodiment of the present invention. FIG. 5 shows an operation when the operation mode is switched from the normal detection mode to the enlargement detection mode at, for example, time (t1 + 68) milliseconds.

  FIG. 6 is a diagram showing an example of the change of the operation mode by the radio wave sensor according to the first embodiment of the present invention. FIG. 6 shows an operation when the operation mode is switched from the enlargement detection mode to the normal detection mode at, for example, time (t2 + 125) milliseconds.

  With reference to FIGS. 5 and 6, comprehensive judgment unit 82 sets an operation mode based on the result of the detection process received from detection unit 4.

  More specifically, the mode setting unit 84 in the overall determination unit 82 selects, for example, the normal detection mode in which the detection process is repeated at the normal execution interval In based on the result of the detection process received from the detection unit 4, and It is set to one of the enlargement detection modes in which the detection process is repeated at the enlargement execution interval Ie.

  Here, the normal execution interval In is, for example, the sum of the length of the transmission period Ttn and the length of the stop period Thn. Further, the expansion execution interval Ie is, for example, the sum of the length of the transmission period Tte and the length of the stop period The.

  The length of the transmission period Ttn and the length of the transmission period Tte are the same, for example. In addition, the length of the stop period The is longer than the length of the stop period Thn. Therefore, the expansion execution interval Ie is longer than the normal execution interval In.

  Hereinafter, each of the transmission period Ttn and the transmission period Tte is also referred to as a transmission period Tt. Each of the stop period Thn and the stop period The is also referred to as a stop period Th.

  For example, the mode setting unit 84 determines whether or not the detection unit 4 has transitioned from the state in which the object Tgt is detected to the state in which the target Tgt is not detected, and the operation mode is enlarged and detected based on the determination result. Set to mode.

  More specifically, for example, the mode setting unit 84 has received object non-detection information from the detection unit 4 indicating that the object Tgt in the target area is not detected in the state where the normal detection mode is set. The above determination is performed based on the number of times, and the normal detection mode is switched to the enlargement detection mode based on the determination result.

  Specifically, for example, when the number of times that the object non-detection information is continuously received from the detection unit 4 becomes equal to or greater than a predetermined threshold value Thc at time (t1 + 68) milliseconds, the mode setting unit 84 detects the detection unit 4. Therefore, it is determined that the object Tgt has transitioned to the undetected state, and the operation mode is switched from the normal detection mode to the expansion detection mode at time (t1 + 68) milliseconds as shown in FIG.

  For example, the mode setting unit 84 determines whether or not the detection unit 4 has transitioned from a state in which the object Tgt is not detected to a detected state, and determines the operation mode based on the determination result. Set to normal detection mode.

  More specifically, for example, when the mode setting unit 84 receives target object detection information indicating that the target object Tgt in the target area has been detected from the detection unit 4 in the state in which the enlargement detection mode is set, the detection unit 4 4 determines that the target Tgt has been detected, and switches the operation mode from the enlarged detection mode to the normal detection mode at the timing when the target detection information is received.

  Specifically, for example, when the mode setting unit 84 receives the object detection information from the detection unit 4 at time (t2 + 125) milliseconds, the operation mode is expanded and detected at time (t2 + 125) milliseconds as shown in FIG. Switch from mode to normal detection mode.

  Further, based on the set operation mode and the remaining amount measurement result received from the battery remaining amount measuring unit 83, the overall determination unit 82 makes a determination regarding the stop of power supply to the radio wave generation unit 31 and the power amplifier 33.

  More specifically, the execution interval setting unit 85 changes the detection processing execution interval, for example, by changing the stop period Th.

  Specifically, the execution interval setting unit 85 sets the stop period based on the current operation mode and the remaining amount measurement result, for example, thereby executing the normal execution interval In of 100 milliseconds and the extended execution of 4000 milliseconds. Set the interval Ie.

  FIG. 7 is a diagram illustrating an example of a normal target area and an enlargement target area in which the radio wave sensor according to the first embodiment of the present invention can detect a target object.

  Referring to FIG. 7, the expansion execution interval Ie is determined as follows, for example. That is, the expansion execution interval Ie is determined based on, for example, the time Tb required for the pedestrian Tgt2 moving on the sidewalk Pv2 to enter the normal target area An1 after entering the expansion target area Ae1.

  Specifically, for example, when the difference between the length of the enlargement target area Ae1 and the length of the normal target area An1 in the crossing direction of the pedestrian crossing PC1 is 20 meters, the pedestrian Tgt2 moves at a speed of 5 meters per second. In this case, the time Tb is approximately 4000 milliseconds at maximum. The expansion execution interval Ie is determined to be 4000 milliseconds, which is the maximum value of the time Tb, for example.

  For example, when the remaining amount measurement result indicates that the remaining battery level is low, specifically, when the remaining battery level is equal to or less than a predetermined value, the execution interval setting unit 85 sets the normal execution interval In and the enlarged execution interval Ie to the following. Set as follows.

  That is, in the normal detection mode, the execution interval setting unit 85 sets a normal execution interval In of 100 milliseconds, for example, as shown in FIGS. 5 and 6, and 50 milliseconds based on the set normal execution interval In. A transmission period Ttn and a stop period Thn of 50 milliseconds are set.

  The execution interval setting unit 85 sets the next normal execution interval In when the operation mode is maintained in the normal detection mode. As a result, the transmission period Ttn and the stop period Thn are alternately repeated.

  Further, the execution interval setting unit 85 sets, for example, an enlargement execution interval Ie of 4000 milliseconds as shown in FIGS. 5 and 6 in the enlargement detection mode, and 50 mm based on the set enlargement execution interval Ie. A second transmission period Tte and a stop period The of 3950 milliseconds are set.

  The execution interval setting unit 85 sets the next expansion execution interval Ie when the operation mode is maintained in the expansion detection mode. Thereby, the transmission period Tte and the stop period The are alternately repeated.

  On the other hand, depending on the route on which the pedestrian Tgt2 moves on the sidewalk Pv2, the time Tb may be shorter than 4000 milliseconds. For this reason, when the remaining amount measurement result indicates that the remaining battery level is sufficient, specifically, when the remaining battery level is larger than the predetermined value, for example, by setting an expansion execution interval Ie shorter than 4000 milliseconds, for example. It is preferable that the frequency of the detection process is increased more than the frequency when the remaining amount of the battery is low.

  Therefore, when the remaining amount measurement result indicates that the remaining battery level is sufficient, the execution interval setting unit 85 sets the expanded execution interval Ie to increase the frequency of the detection process from the frequency when the remaining battery level is low. Set as follows.

  That is, the execution interval setting unit 85 sets, for example, an expansion execution interval Ie of 2000 milliseconds in the expansion detection mode, and a transmission period Tte of 50 milliseconds and a stop of 1950 milliseconds based on the set expansion execution interval Ie. A period The is set.

  Further, for example, for the normal execution interval In, the execution interval setting unit 85 sets a normal execution interval In of 100 milliseconds as shown in FIGS. 5 and 6 regardless of the remaining battery level.

  For example, when the operation mode is switched, the execution interval setting unit 85 sets the normal execution interval In and the enlarged execution interval Ie as follows. That is, for example, as shown in FIG. 5, the execution interval setting unit 85 detects that the operation mode is expanded from the normal detection mode at time (t1 + 68) milliseconds before the time corresponding to the normal execution interval In elapses from time t1. The following processing is performed when switching to the mode. That is, for example, the execution interval setting unit 85 newly sets an enlarged execution interval Ie from time t1 to time (t1 + 4100) milliseconds starting from time (t1 + 100) milliseconds when the time corresponding to the normal execution interval In elapses. Then, a transmission period Tte and a stop period The are newly set.

  Further, for example, as shown in FIG. 6, the execution interval setting unit 85 normally detects the operation mode from the expansion detection mode at time (t2 + 125) milliseconds before the time corresponding to the expansion execution interval Ie elapses from time t2. The following processing is performed when switching to the mode. That is, for example, the execution interval setting unit 85 shortens the expansion execution interval Ie to the expansion execution interval Iei of 125 milliseconds at the switching time (t2 + 125) milliseconds, and the time (t2 + 225) milliseconds starting from the time (t2 + 125) milliseconds. A normal execution interval In up to seconds is newly set, and a transmission period Ttn and a stop period Thn are newly set.

  The execution interval setting unit 85 can also set other contents for the normal execution interval In and the enlarged execution interval Ie. In addition, the execution interval setting unit 85 can set other contents for the length of the transmission period Tt and the length of the stop period Th.

  Specifically, for example, the execution interval setting unit 85 sets a normal execution interval In of 100 milliseconds, and sets a transmission period Ttn of 100 milliseconds and a stop period Thn of zero milliseconds based on the set normal execution interval In. It may be set.

[Control of power supply]
The supplied power interrupting unit 80 performs the following processing based on the power supplied from the battery B1. That is, for example, as shown in FIGS. 5 and 6, the supply power interrupting unit 80 supplies the power Pcn to the radio wave generation unit 31 and the power amplifier 33 in the transmission wave processing unit 10 in the transmission period Ttn. Further, the supply power interrupting unit 80 supplies, for example, power Pce larger than the power Pcn to the radio wave generating unit 31 and the power amplifier 33 in the transmission period Tte. Therefore, radio waves are transmitted from the transmission wave processing unit 10 via the transmission antenna 11 in the transmission periods Ttn and Tte.

  On the other hand, the supply power interrupting unit 80 stops the supply of power to the radio wave generating unit 31 and the power amplifier 33 in the stop periods Thn and The, for example. Accordingly, the transmission of radio waves from the transmission wave processing unit 10 is stopped in the stop periods Thn and The.

[Change target area range]
For example, the amplification factor control unit 81 changes the range of the target area depending on whether or not a predetermined condition including a condition related to the result of the detection process is satisfied. Specifically, the amplification factor control unit 81 changes the range of the target area by changing the transmission power of the transmission unit 1, for example, by setting the amplification factor of the power amplifier 33 according to the operation mode.

  Specifically, the amplification factor control unit 81 sets the amplification factor of the power amplifier 33 to Gn in the transmission period Ttn and the stop period Thn based on the normal execution interval In, for example, as shown in FIGS. Further, the amplification factor of the power amplifier 33 is set to Ge larger than Gn in the transmission period Tte and the stop period The based on the expansion execution interval Ie.

  Therefore, the power of the radio wave transmitted from the transmission wave processing unit 10 via the transmission antenna 11 in the transmission period Tte is greater than the power of the radio wave transmitted from the transmission wave processing unit 10 via the transmission antenna 11 during the transmission period Ttn.

  Specifically, a radio wave is transmitted to the expansion target area Ae1 during the transmission period Tte, and a radio wave is transmitted to the normal target area An1 during the transmission period Ttn. That is, the range of the target area in the transmission period Tte is larger than the range of the target area in the transmission period Ttn.

  The amplification factor control unit 81 is configured to set the amplification factor of the power amplifier 33 to Gn in the transmission period Ttn and the stop period Thn. However, the present invention is not limited to this. For example, the amplification factor control unit 81 may be configured to set the amplification factor of the power amplifier 33 to Gn at least in the transmission period Ttn.

  Further, although the amplification factor control unit 81 is configured to set the amplification factor of the power amplifier 33 to Ge in the transmission period Tte and the stop period The, it is not limited to this. The amplification factor control unit 81 may be configured to set the amplification factor of the power amplifier 33 to Ge at least in the transmission period Tte, for example.

[Radio wave transmission processing]
Referring to FIG. 4 again, the transmission wave processing unit 10 in the transmission unit 1 continuously transmits radio waves through the transmission antenna 11 in the transmission period Tt and transmits radio waves in the stop period Th according to the control of the control unit 5. To stop.

  More specifically, the radio wave generating unit 31 generates a radio wave having a frequency of, for example, 24 GHz, that is, a millimeter wave, using the power received from the supplied power interrupting unit 80 in the transmission period Tt. Then, the radio wave generator 31 outputs the generated millimeter wave to the directional coupler 32.

  Note that the radio wave generator 31 may generate a radio wave having a frequency of, for example, 60 GHz band, 76 GHz band, or 79 GHz band. The radio wave generator 31 may generate a radio wave having a frequency in the microwave band lower than that of the millimeter wave band, for example, or a radio wave having a frequency in the terahertz band higher than that in the millimeter wave band. May be.

  More specifically, the frequency switching unit 35 in the radio wave generation unit 31 generates a switching signal for alternately switching the frequency of a transmission wave that is a radio wave transmitted from the transmission antenna 11 at a predetermined switching frequency fswt, and the voltage generation unit 36 and Output to the signal processing unit 3.

  Specifically, as shown in FIGS. 5 and 6, for example, the frequency switching unit 35 sets the level Ls to a high level and a low level at a switching frequency fswt of 10 kilohertz, that is, at a cycle of 0.1 milliseconds, in the transmission period Tt. A switching signal for switching to the level is output to the voltage generator 36 and the signal processor 3. Further, in the stop period Th, the level Ls of the switching signal becomes, for example, zero.

  For example, the voltage generator 36 sets control voltages Vf1 and Vf2 for causing the voltage-controlled oscillator 37 to generate radio waves having predetermined transmission frequencies f1 and f2. The difference between the transmission frequencies f2 and f1 is, for example, about several megahertz.

  For example, when the level Ls of the switching signal received from the frequency switching unit 35 is a low level, the voltage generating unit 36 generates the control voltage Vf1 and outputs the generated control voltage Vf1 to the voltage controlled oscillator 37. For example, when the level Ls of the switching signal is high, the voltage generator 36 generates the control voltage Vf2 and outputs the generated control voltage Vf2 to the voltage controlled oscillator 37.

  The voltage control oscillator 37 is specifically a VCO (Voltage-controlled oscillator), and generates a millimeter-wave band transmission wave having a frequency corresponding to the control voltages Vf1 and Vf2 received from the voltage generator 36.

More specifically, the voltage-controlled oscillator 37 receives the control voltage Vf1 based on the low-level switching signal from the voltage generator 36 as shown in FIGS. 5 and 6, for example. The transmission wave T1 (t) having the frequency f1 shown in FIG.

Here, φ1 is an initial phase. In the formula (1) and the following formulas, t represents time. Further, for example, as shown in FIGS. 5 and 6, the voltage controlled oscillator 37 receives the control voltage Vf <b> 2 based on the high level switching signal from the voltage generator 36, and the frequency shown in the following equation (2). A transmission wave T2 (t) having f2 is generated.

  Here, φ2 is an initial phase. The amplitude of the transmission wave T1 (t) and the amplitude of the transmission wave T2 (t) are both A, for example. The voltage controlled oscillator 37 alternately generates transmission waves T1 (t) and T2 (t) and outputs them to the directional coupler 32.

  The directional coupler 32 distributes the transmission waves T1 (t) and T2 (t) received from the radio wave generator 31 to the power amplifier 33 and the receiver 2. The power amplifier 33 uses the power received from the supply power interrupting unit 80 to amplify the transmission waves T1 (t) and T2 (t) received from the directional coupler 32 by the amplification factor control unit 81 in the control unit 5. Amplify at rate.

  Specifically, the power amplifier 33 amplifies the transmission wave received from the directional coupler 32 with the amplification factor Gn when the amplification factor is set to Gn by the amplification factor controller 81 and has, for example, power of 0 dBm. The transmission waves T1 (t) and T2 (t) are alternately transmitted to the normal target area An1 via the transmission antenna 11.

  In addition, when the amplification factor is set to Ge by the amplification factor control unit 81, the power amplifier 33 amplifies the transmission wave received from the directional coupler 32 with the amplification factor Ge, for example, the transmission wave T1 having a power of 6 dBm. (T) and T2 (t) are transmitted alternately to the enlargement target area Ae1 via the transmission antenna 11.

  As shown in FIG. 1, the transmission antenna 11 is installed such that the direction of directivity Dn is along the crossing direction of the pedestrian crossing PC1. Here, the directivity direction Dn is, for example, a direction from the radio wave sensor 101 to a position Cn at the substantially center of the pedestrian crossing PC1.

  Preferably, the transmission antenna 11 is, for example, a direction in which the direction Dn of directivity is projected onto the plane of the pedestrian crossing PC1 in the normal direction of the plane, and a direction in which the pedestrian Tgt2 moves the pedestrian crossing PC1 in the target area. It is installed so that vm, that is, the direction vm2 is parallel or antiparallel.

[Radio wave reception processing]
FIG. 8 is a diagram illustrating a configuration of a reception wave processing unit in the reception unit according to the first embodiment of the present invention.

  Referring to FIG. 8, received wave processing unit 12 includes a low noise amplifier 41, a mixer 42, an IF (Intermediate Frequency) amplifier 43, a low pass filter 44, and an A / D converter (ADC) 45.

  FIG. 9 is a diagram illustrating an example of the arrangement of the transmission antenna, the reception antenna, and the object according to the first embodiment of the present invention.

  With reference to FIG. 8 and FIG. 9, the reception wave processing unit 12 in the reception unit 2 receives a radio wave from the target area, for example, a reflected wave, via the reception antenna 13. Here, the reception antenna 13 reflects the reflected wave R1 (t) or R2 (t generated in the transmission period Tt by reflecting the transmission wave T1 (t) or T2 (t) by the object Tgt in the target area, respectively. ) Can be received.

  Specifically, the reception antenna 13 may be the same antenna as the transmission antenna 11 or may be a different antenna. In the case where the transmission antenna 11 and the reception antenna 13 are separate antennas, the reception antenna 13 may be arranged at a position away from the transmission antenna 11, but the transmission antenna 11 is simplified in order to simplify the configuration of the radio wave sensor 101. 11 is preferably arranged in the vicinity of 11.

  More specifically, the reflected wave received by the receiving antenna 13 includes, for example, a Doppler reflected wave generated when the object Tgt moving in the target area reflects the transmitted wave transmitted by the transmitting antenna 11. .

  Here, the moving speed of the object Tgt along the direction approaching or moving away from the radio wave sensor 101 is defined as a detection target speed vd. In other words, the component of the relative speed of the target Tgt with respect to the receiving antenna 13 along the direction approaching or moving away from the radio wave sensor 101 is the detection target speed vd.

  For example, if the speed of the target Tgt relative to the receiving antenna 13 is defined as a relative speed vt, the detection target speed vd is represented by the inner product of the unit vector nd in the direction from the target Tgt to the receiving antenna 13 and the relative speed vt. . Note that the radio wave sensor 101 may be fixed to, for example, a support that does not move with respect to the ground, such as the column P1, or may be fixed to a thing that moves with respect to the ground. For example, when the radio wave sensor 101 is fixed to the support P1, the receiving antenna 13 and the target area are fixed with respect to the ground, so the relative speed vt is also the relative speed of the target Tgt with respect to the ground.

  The frequencies f1r and f2r of the Doppler reflected waves from the target Tgt received by the receiving antenna 13 are shifted with respect to the frequencies f1 and f2 of the transmitted waves according to the detection target speed vd corresponding to the target Tgt. Further, the amplitude of the Doppler reflected wave is an amplitude corresponding to the reflection cross-sectional area σ of the object Tgt.

More specifically, in the case where the transmission wave T1 (t) is expressed by the equation (1), for example, when the reception antenna 13 is disposed in the vicinity of the transmission antenna 11, the Doppler reflected wave R1d (t) As shown in Patent Document 1 or Non-Patent Document 2, it is expressed by the following equation (3).

  Here, L is the distance between the receiving antenna 13 and the object Tgt. c is the speed of light. For example, a is a value determined by the amplitude A and wavelength of the transmission wave T1 (t), the antenna gains of the transmission antenna 11 and the reception antenna 13, the distance L, the reflection cross section σ, and the like.

  The frequency f1r of the Doppler reflected wave R1d (t) is a frequency obtained by adding f1 × (2 × vd / c) to the frequency f1 of the transmission wave T1 (t) as shown in Expression (3). Specifically, when the object Tgt moves in a direction approaching the receiving antenna 13, vd becomes positive, so the frequency f1r is higher than the frequency f1, and the object Tgt moves away from the receiving antenna 13. When vd becomes negative, the frequency f1r is lower than the frequency f1.

The reflected wave R1 (t) received by the receiving antenna 13 generally includes a Doppler reflected wave R1d (t) and a non-Doppler reflected wave R1nd (t) from a portion other than the object Tgt. Therefore, the reflected wave R1 (t) is a superposition of the Doppler reflected wave R1d (t) and the non-Doppler reflected wave R1nd (t), and is expressed by the following equation (4).

  Here, a situation is assumed in which the detection target velocity vd other than the object Tgt is zero, that is, a situation where the frequency of the non-Doppler reflected wave R1nd (t) is the same as the frequency f1 of the transmission wave T1 (t).

Similarly, the reception wave processing unit 12 is derived in the same manner as Expressions (1), (3), and (4) during the period in which the transmission wave T2 (t) is transmitted from the transmission antenna 11, and the following expression ( The reflected wave R2 (t) shown in 5) is received via the receiving antenna 13.

  Here, since the amplitudes of the transmission waves T1 (t) and T2 (t) are both A and the frequencies f1 and f2 are substantially the same, the amplitude of the Doppler reflected wave R2d (t) is expressed by the equation (3). It can be represented by a.

  Referring to FIG. 8 again, the low noise amplifier 41 in the reception wave processing unit 12 amplifies the reflected waves R1 (t) and R2 (t) received by the reception antenna 13 and outputs them to the mixer 42.

  The mixer 42 performs the following processing during the period in which the transmission wave T1 (t) is transmitted from the transmission unit 1. That is, the mixer 42 multiplies the transmission wave T1 (t) received from the directional coupler 32 in the transmission wave processing unit 10 by the reflected wave R1 (t) received from the low noise amplifier 41. The mixer 42 then outputs a difference signal having a frequency component that is the difference between the frequency component of the transmission wave T1 (t) and the frequency component of the reflected wave R1 (t) and a sum frequency signal having a frequency component that is the sum of both frequency components. Generate.

In the mixer 42, the difference signal B1 (t) generated from the transmission wave T1 (t) and the reflected wave R1 (t) is expressed by the following equation (6).

  Here, B1d (t) is a differential signal generated from the transmission wave T1 (t) and the Doppler reflected wave R1d (t). K is the amplitude of the difference signal B1d (t). −4π × f1 × L / c is the delay phase θ1. 2 × f1 × vd / c is the Doppler frequency f1d. D1 is a differential signal generated from the transmission wave T1 (t) and the non-Doppler reflected wave R1nd (t), and the frequency of the non-Doppler reflected wave R1nd (t) is the frequency f1 of the transmission wave T1 (t). Therefore, it becomes a direct current component.

Similarly, the mixer 42 performs the following processing during a period in which the transmission wave T2 (t) is transmitted from the transmission unit 1. That is, the mixer 42 multiplies the transmission wave T2 (t) and the reflected wave R2 (t) to generate a difference signal B2 (t) and a sum frequency signal expressed by the following equation (7).

  Here, B2d (t) is a differential signal generated from the transmission wave T1 (t) and the Doppler reflected wave R2d (t). K is the amplitude of the difference signal B2d (t). −4π × f2 × L / c is the delay phase θ2. 2 × f2 × vd / c is the Doppler frequency f2d. D2 is a direct current difference signal generated from the transmission wave T2 (t) and the non-Doppler reflected wave R2nd (t).

  The mixer 42 outputs the generated difference signals B1 (t), B2 (t) and the sum frequency signal to the IF amplifier 43.

  The IF amplifier 43 is an amplifier having a large amplification factor from, for example, a low frequency band to an intermediate frequency band. The differential signal B1 (t) and B2 (t) generated in the mixer 42 and the difference signal B1 ( t) and B2 (t) are amplified with a large amplification factor, and the amplified differential signals B1 (t) and B2 (t) are output to the low-pass filter 44.

  The low-pass filter 44 attenuates a component having a predetermined frequency or higher, for example, a component having a frequency of 1 kilohertz or higher, among the frequency components of the differential signals B1 (t) and B2 (t) amplified by the IF amplifier 43.

  The A / D converter 45 performs sampling processing of the difference signals B1 (t) and B2 (t), for example, at a predetermined sampling frequency fsmpl. More specifically, the A / D converter 45 converts the difference signals B1 (t) and B2 (t), which are analog signals that have passed through the low-pass filter 44, into q bits (qf) for each sampling period (1 / fsmpl). Is an integer of 2 or more). The A / D converter 45 outputs the converted digital signal to the signal processing unit 3.

[Signal processing]
FIG. 10 is a diagram showing a configuration of a signal processing unit in the radio wave sensor according to the first embodiment of the present invention. Referring to FIG. 10, signal processing unit 3 includes a buffer control unit 71, a first buffer 72, a second buffer 73, and an FFT processing unit 74.

  The signal processing unit 3 processes the digital signal received from the receiving unit 2. More specifically, the buffer control unit 71 in the signal processing unit 3 receives the digital signal received from the reception unit 2 based on the level Ls of the switching signal received from the transmission unit 1 during the transmission period Tt. The data is accumulated while being distributed to the buffer 73.

  Specifically, for example, the buffer control unit 71 receives the digital signal received from the reception unit 2 during a period during which the low-level switching signal is received, that is, during the period during which the transmission unit 1 transmits the transmission wave T1 (t) having the frequency f1. The signals are accumulated in the first buffer 72 in chronological order. In addition, the buffer control unit 71 receives the digital signal received from the reception unit 2 during a period in which, for example, a high-level switching signal is received, that is, in a period in which the transmission unit 1 transmits the transmission wave T2 (t) having the frequency f2. 2 is stored in the buffer 73 in chronological order.

  For example, when the level Ls of the switching signal becomes zero, the buffer control unit 71 recognizes that the transmission period Tt has expired, and ends the accumulation of the digital signal. Then, the buffer control unit 71 outputs a storage completion notification to the FFT processing unit 74, for example.

  Therefore, at the timing when the accumulation completion notification is output, the first buffer 72 stores a digital signal based on the difference signal B1 (t) in the transmission period Tt, that is, the time spectrum TS1, and the second buffer 73 stores A digital signal based on the difference signal B2 (t) in the transmission period Tt, that is, the time spectrum TS2 is accumulated.

  For example, when receiving an accumulation completion notification from the buffer control unit 71, the FFT processing unit 74 performs Doppler spectrum DS1 and phase spectrum PS1 by fast Fourier transforming the time spectrum TS1 accumulated in the first buffer 72. In addition, the FFT processing unit 74 creates the Doppler spectrum DS2 and the phase spectrum PS2, for example, by performing fast Fourier transform on the time spectrum TS2 stored in the second buffer 73.

  The FFT processing unit 74 outputs the created Doppler spectra DS1 and DS2 and the phase spectra PS1 and PS2 to the detection unit 4.

[Detection processing]
FIG. 11 is a diagram illustrating a configuration of a detection unit in the radio wave sensor according to the first embodiment of the present invention. Referring to FIG. 11, detection unit 4 includes a spectrum analysis unit 76 and an analysis result determination unit 77.

  More specifically, for example, in the transmission period Tt, the detection unit 4 performs the above detection process for one time based on the radio wave received by the reception unit 2.

  Specifically, the spectrum analysis unit 76 in the detection unit 4 analyzes the Doppler spectra DS1 and DS2 and the phase spectra PS1 and PS2 received from the FFT processing unit 74 and outputs the analysis results to the analysis result determination unit 77.

More specifically, for example, the spectrum analysis unit 76 searches for one or a plurality of peaks in the Doppler spectrum DS1, and acquires the Doppler frequency f1dmax that is the frequency of the searched peak. The spectrum analysis unit 76 calculates the detection target velocity vd of the target Tgt from the acquired Doppler frequency f1dmax using, for example, the following equation (8). Note that the spectrum analysis unit 76 may calculate the detection target speed vd from the Doppler spectrum DS2, for example.

Further, the spectrum analysis unit 76 refers to the phase spectra PS1 and PS2, for example, and acquires the delay phases θ1max and θ2max corresponding to the Doppler frequency f1dmax, respectively. For example, the spectrum analysis unit 76 calculates the distance L from the acquired delay phases θ1max and θ2max to the object Tgt using the following equation (9).

  The spectrum analysis unit 76 outputs, for example, the peak intensity, the detection target speed vd and the distance L corresponding to the peak as analysis results to the analysis result determination unit 77.

  The analysis result determination unit 77 detects the object Tgt in the target area based on the analysis result received from the spectrum analysis unit 76. For example, when the analysis result determination unit 77 detects the target Tgt in the target area, the analysis result determination unit 77 outputs the target detection information to the control unit 5 and the signal control device 151. For example, when the target Tgt in the target area is not detected, the analysis result determination unit 77 outputs the target non-detection information to the control unit 5 and the signal control device 151.

[effect]
Referring to FIGS. 5 and 6 again, as described above, in the period corresponding to the normal execution interval In of 100 milliseconds, a radio wave having a power of 0 dBm, that is, 1 milliwatt is transmitted for 50 milliseconds, and 4000 milliseconds. In a period corresponding to the second extended execution interval Ie, a radio wave having a power of 6 dBm, that is, about 4 milliwatts is transmitted for 50 milliseconds.

  Therefore, when the ratio of the powers Pce and Pcn supplied by the power supply interrupting unit 80 is approximated to 4, which is a ratio of 4 milliwatts and 1 milliwatt, for example, the average power consumption in the period corresponding to the normal execution interval In is (Pcn / 2 The average power consumption in the period corresponding to the extended execution interval Ie is ((4 × Pcn) / 80) milliwatts.

  Here, the value obtained by subtracting ((4 × Pcn) / 80) milliwatts from (Pcn / 2) milliwatts is ((36 × Pcn) / 80) milliwatts. Since Pcn is positive, ((36 × Pcn) / 80) milliwatts is a positive value. In other words, power corresponding to ((36 × Pcn) / 80) milliwatts can be saved on average in the period corresponding to the expansion execution interval Ie.

  For example, the average power consumption when the expansion execution interval Ie is 2000 milliseconds is ((4 × Pcn) / 40) milliwatts. Therefore, the value obtained by subtracting ((4 × Pcn) / 40) milliwatts from (Pcn / 2) milliwatts is ((16 × Pcn) / 40) milliwatts. Since Pcn is positive, ((16 × Pcn) / 40) milliwatts is a positive value. That is, even when the expansion execution interval Ie is 2000 milliseconds, it is possible to save power on average.

  From the above calculation, when the ratio of the powers Pce and Pcn is approximated to 4, if the expansion execution interval Ie is longer than four times the normal execution interval In, it is possible to save power on average during the period corresponding to the expansion execution interval Ie. I understand.

[Variation 1 of the radio wave sensor 101]
FIG. 12 is a diagram showing a configuration of a modification of the radio wave sensor according to the first embodiment of the present invention.

  Referring to FIG. 12, radio wave sensor 102, which is a modification of radio wave sensor 101 shown in FIG. 2, has transmission unit 6 and control unit 7 instead of transmission unit 1 and control unit 5 compared to radio wave sensor 101. Prepare. Compared to the transmission unit 1 shown in FIG. 2, the transmission unit 6 includes a far-field transmission antenna 15 and a normal transmission antenna 16 instead of the transmission antenna 11, and further includes an antenna switch 14. The far-field transmission antenna 15 and the normal transmission antenna 16 are not limited to the configuration provided in the radio wave sensor 102, and may be provided outside the radio wave sensor 102.

  The operations of the receiver 2, the signal processor 3, and the detector 4 are the same as those of the receiver 2, the signal processor 3, and the detector 4 shown in FIG. The operation of the transmission wave processing unit 10 in the transmission unit 6 is the same as that of the transmission wave processing unit 10 in the transmission unit 1 shown in FIG. For example, a fixed value is set for the amplification factor of the power amplifier 33 in the transmission wave processing unit 10.

  FIG. 13 is a diagram showing a configuration of a control unit in a modification of the radio wave sensor according to the first embodiment of the present invention.

  Referring to FIG. 13, control unit 7 includes an antenna switching control unit 86 instead of amplification rate control unit 81 as compared with control unit 5 shown in FIG. 3.

  The operations of the supply power interrupting unit 80, the comprehensive judgment unit 82, and the battery remaining amount measuring unit 83 in the control unit 7 are the same as the operation of the supply power interrupting unit 80, the overall judgment unit 82, and the battery remaining amount measuring unit 83 in the control unit 5 shown in FIG. And the same for each.

  FIG. 14 is a diagram illustrating an example of a change in the operation mode according to a modification of the radio wave sensor according to the first embodiment of the invention. FIG. 14 shows the operation when the operation mode is switched from the normal detection mode to the enlargement detection mode at time (t1 + 68) milliseconds, for example, as in FIG. The time change of the level Ls of the switching signal shown in FIG. 14 is the same as the time change of the level Ls of the switching signal shown in FIG.

  FIG. 15 is a diagram illustrating an example of a change in operation mode according to a modification of the radio wave sensor according to the first embodiment of the invention. FIG. 15 shows the operation when the operation mode is switched from the enlargement detection mode to the normal detection mode, for example, at time (t2 + 125) milliseconds, as in FIG. The time change of the level Ls of the switching signal shown in FIG. 15 is the same as the time change of the level Ls of the switching signal shown in FIG.

  Referring to FIGS. 12 to 15, normal transmission antenna 16 has the same directivity as, for example, transmission antenna 11 shown in FIG. 2, and the direction of directivity is, for example, in the transverse direction of pedestrian crossing PC1. It is installed along. Therefore, the target area when the transmission waves T1 (t) and T2 (t) with predetermined power are transmitted from the normal transmission antenna 16 is, for example, the normal target area An1 illustrated in FIGS.

  Further, the far transmission antenna 15 has a long directivity in the beam direction by extending the cover distance by narrowing the beam width and increasing the gain with respect to the normal transmission antenna 16, for example. Therefore, the target area when the transmission waves T1 (t) and T2 (t) of the predetermined power are transmitted from the far-field transmission antenna 15 is, for example, an expansion target area Ae2 shown in FIG.

  For example, as illustrated in FIGS. 14 and 15, the supply power interrupting unit 80 illustrated in FIG. 13 supplies power Pc2 to the radio wave generation unit 31 and the power amplifier 33 in the transmission wave processing unit 10 in the transmission periods Ttn and Tte. Since the amplification factor of the power amplifier 33 is a fixed value, the power supplied to the power amplifier 33 in the transmission periods Ttn and Tte is the same, for example.

  For example, the antenna switching control unit 86 changes the range of the target area depending on whether or not a predetermined condition including a condition related to the result of the detection process is satisfied. Specifically, the antenna switching control unit 86 changes the range of the target area by switching the antenna switch 14 in the transmission unit 6 according to the type of the execution interval and changing the antenna directivity in the transmission unit 6, for example. In other words, the range of the target area is changed by changing the gain of the antenna in the transmission unit 6.

  More specifically, for example, as shown in FIGS. 14 and 15, the antenna switching control unit 86 includes the output terminal of the power amplifier 33 and the normal transmission antenna in the transmission period Ttn and the stop period Thn based on the normal execution interval In. 16 is electrically connected. Therefore, in the transmission period Ttn, the transmission wave processing unit 10 transmits radio waves to the normal target area An1 via the normal transmission antenna 16.

  Further, for example, as shown in FIGS. 14 and 15, the antenna switching control unit 86 connects the output end of the power amplifier 33 and the far-end transmission antenna 15 in the transmission period Tte and the stop period The based on the expansion execution interval Ie. Connect electrically. Therefore, in the transmission period Tte, the transmission wave processing unit 10 transmits a radio wave to the enlargement target area Ae2 via the remote transmission antenna 15.

  The antenna switching control unit 86 is configured to electrically connect the output terminal of the power amplifier 33 and the normal transmission antenna 16 in the transmission period Ttn and the stop period Thn. However, the present invention is not limited to this. . The antenna switching control unit 86 may be configured to electrically connect the output terminal of the power amplifier 33 and the normal transmission antenna 16 at least in the transmission period Ttn, for example.

  In addition, the antenna switching control unit 86 is configured to electrically connect the output terminal of the power amplifier 33 and the remote transmission antenna 15 in the transmission period Tte and the stop period The, but the present invention is not limited to this. Absent. For example, the antenna switching control unit 86 may be configured to electrically connect the output terminal of the power amplifier 33 and the far-field transmission antenna 15 at least in the transmission period Tte.

[Variation 2 of the radio wave sensor 101]
FIG. 16 is a diagram showing a configuration of a modified example of the radio wave sensor according to the first embodiment of the present invention.

  Referring to FIG. 16, radio wave sensor 103, which is a modification of radio wave sensor 101 shown in FIG. 2, has transmission unit 8 and control unit 9 instead of transmission unit 1 and control unit 5 compared to radio wave sensor 101. Prepare. The transmission unit 8 includes a tilt variable transmission antenna 18 instead of the transmission antenna 11 as compared with the transmission unit 1 shown in FIG. The variable tilt transmission antenna 18 is not limited to the configuration provided in the radio wave sensor 103, and may be provided outside the radio wave sensor 103.

  The operations of the receiver 2, the signal processor 3, and the detector 4 are the same as those of the receiver 2, the signal processor 3, and the detector 4 shown in FIG. The operation of the transmission wave processing unit 10 in the transmission unit 8 is the same as that of the transmission wave processing unit 10 in the transmission unit 1 shown in FIG. For example, a fixed value is set for the amplification factor of the power amplifier 33 in the transmission wave processing unit 10.

  FIG. 17 is a diagram illustrating a configuration of a control unit in a modification of the radio wave sensor according to the first embodiment of the invention.

  Referring to FIG. 17, control unit 9 includes a tilt angle control unit 87 instead of amplification factor control unit 81 as compared with control unit 5 shown in FIG. 3.

  The operations of the supply power interrupting unit 80, the comprehensive judgment unit 82, and the battery remaining amount measuring unit 83 in the control unit 9 are the same as the operation of the supply power intermittent unit 80, the overall judging unit 82, and the battery remaining amount measuring unit 83 in the control unit 5 shown in FIG. And the same for each.

  FIG. 18 is a diagram illustrating an example of a change in operation mode according to a modification of the radio wave sensor according to the first embodiment of the invention. FIG. 18 shows the operation when the operation mode is switched from the normal detection mode to the enlargement detection mode at time (t1 + 68) milliseconds, for example, as in FIG. The time change of the level Ls of the switching signal shown in FIG. 18 is the same as the time change of the level Ls of the switching signal shown in FIG.

  FIG. 19 is a diagram illustrating an example of the change of the operation mode according to the modification of the radio wave sensor according to the first embodiment of the invention. FIG. 19 shows the operation when the operation mode is switched from the enlargement detection mode to the normal detection mode at time (t2 + 125) milliseconds, for example, as in FIG. The time change of the level Ls of the switching signal shown in FIG. 19 is the same as the time change of the level Ls of the switching signal shown in FIG.

  FIG. 20 is a diagram illustrating an example of the directivity direction of the variable tilt transmission antenna in the modification example of the radio wave sensor according to the first embodiment of the invention. FIG. 20 shows tilt angles αn and αe indicating the orientation of the variable tilt transmission antenna 18 with respect to the vertically downward direction on a vertical plane that includes the directivity directions Dn and De of the variable tilt transmission antenna 18.

  Referring to FIGS. 16 to 20, for example, as shown in FIGS. 18 and 19, supply power interrupting unit 80 shown in FIG. 17 includes radio wave generation unit 31 in transmission wave processing unit 10 and transmission period Ttn and Tte. Electric power Pc3 is supplied to the power amplifier 33. Since the amplification factor of the power amplifier 33 is a fixed value, the power supplied to the power amplifier 33 is the same during the transmission periods Ttn and Tte.

  For example, the tilt angle control unit 87 changes the range of the target area depending on whether or not a predetermined condition including a condition related to the result of the detection process is satisfied. Specifically, the tilt angle control unit 87 changes the direction of the antenna in the transmission unit 8, for example, by switching the direction of the tilt variable transmission antenna 18 in the transmission unit 8, that is, the tilt angle according to the type of execution interval. The range of the target area is changed.

  Specifically, for example, as shown in FIGS. 18 and 19, the tilt angle control unit 87 sets the tilt angle of the tilt variable transmission antenna 18 to αn in the transmission period Ttn and the stop period Thn based on the normal execution interval In. By setting, the directivity direction Dn is set so as to be directed to a substantially central position Cn of the pedestrian crossing PC1 shown in FIGS.

  Accordingly, in the transmission period Ttn, the target areas in the case where the transmission waves T1 (t) and T2 (t) having predetermined power are transmitted from the tilt variable transmission antenna 18 having the tilt angle αn are shown in FIGS. It becomes the normal target area An1 shown.

  Further, for example, as shown in FIGS. 18 and 19, the tilt angle control unit 87 sets the tilt angle of the variable tilt transmission antenna 18 to αe larger than αn in the transmission period Tte and the stop period The based on the enlargement execution interval Ie. By setting, the directivity direction De is set to face the following direction. In other words, the tilt angle control unit 87 is, for example, the radio wave sensor 103 so that the directionality De of the transmission wave is along the crossing direction of the pedestrian crossing PC1 and compared with the position Cn shown in FIGS. It is set so as to face the position Ce away from.

  Therefore, the direction of the tilt variable transmission antenna 18 in the transmission period Tte and the stop period The is higher than the direction of the tilt variable transmission antenna 18 in the transmission period Ttn and the stop period Thn. Further, in the transmission period Tte, the target areas in the case where the transmission waves T1 (t) and T2 (t) having the predetermined power are transmitted from the tilt variable transmission antenna 18 having the tilt angle αe are, for example, FIG. 1 and FIG. The enlargement target area Ae1 shown in FIG.

  The tilt angle control unit 87 is configured to set the tilt angle of the tilt variable transmission antenna 18 to αn in the transmission period Ttn and the stop period Thn, but is not limited to this. For example, the tilt angle control unit 87 may be configured to set the tilt angle of the tilt variable transmission antenna 18 to αn at least in the transmission period Ttn.

  Further, the tilt angle control unit 87 is configured to set the tilt angle of the tilt variable transmission antenna 18 to αe in the transmission period Tte and the stop period The, but is not limited thereto. For example, the tilt angle control unit 87 may be configured to set the tilt angle of the tilt variable transmission antenna 18 to αe at least in the transmission period Tte.

[Operation]
FIG. 21 is a flowchart defining an operation procedure when the radio wave sensor according to the first embodiment of the present invention detects an object in a target area according to an operation mode. The radio wave sensor 101 in the signal control system 201 includes a computer, and an arithmetic processing unit such as a CPU in the computer reads and executes a program including a part or all of each step of the following flowchart from a memory (not shown). The program of this apparatus can be installed from the outside. The program of this device is distributed in a state stored in a recording medium.

  Referring to FIG. 21, first, control unit 5 in radio wave sensor 101 repeats the enlargement detection process when the operation mode is maintained in the enlargement detection mode (YES in step S102) (step S104).

  On the other hand, when the operation mode is maintained in the normal detection mode (NO in step S102), the control unit 5 repeatedly performs the normal detection process (step S106).

  FIG. 22 is a flowchart defining an operation procedure when the radio wave sensor according to the first embodiment of the present invention detects an object in the enlargement target area in the enlargement detection mode. FIG. 22 shows details of the operation of the enlargement detection process in step S104 of FIG.

  With reference to FIG. 22, first, the control unit 5 in the radio wave sensor 101 sets an enlargement execution interval Ie (step S202).

  Next, until the transmission period Tte based on the expansion execution interval Ie set by the control unit 5 expires (NO in step S204), the transmission unit 1 transmits radio waves to the expansion target area Ae1 (step S206), or The receiving unit 2 receives radio waves from the enlargement target area Ae1 (step S208).

  On the other hand, when the transmission period Tte expires (YES in step S204), the control unit 5 stops the transmission of radio waves from the transmission unit 1 by stopping the power supply to the transmission unit 1 in the stop period The ( Step S210).

  Next, the detection unit 4 performs a detection process based on the radio wave received by the reception unit 2 in the transmission period Tte (step S212).

  Next, when the target Tgt is not detected as a result of the detection process (NO in step S214), the control unit 5 continues to stop the power supply to the transmission unit 1 until the stop period The expires. The transmission of radio waves from the unit 1 is continued (step S216).

  Next, when the stop period The expires, the control unit 5 sets the next expansion execution interval Ie (step S202).

  Further, when the object Tgt is detected as a result of the detection process (YES in step S214), the control unit 5 switches from the enlargement detection mode to the normal detection mode (step S218).

  Next, the control unit 5 shortens the enlargement execution interval Ie at the timing of switching to the normal detection mode, thereby ending the enlargement detection process and starting the normal detection process (step S220).

  FIG. 23 is a flowchart defining an operation procedure when the radio wave sensor according to the first embodiment of the present invention detects an object in the normal target area in the normal detection mode. FIG. 23 shows details of the operation of the normal detection process in step S106 of FIG.

  Referring to FIG. 23, first, control unit 5 in radio wave sensor 101 resets count value Cnt to zero (step S302).

  Next, the control unit 5 sets a normal execution interval In (step S304).

  Next, until the transmission period Ttn based on the normal execution interval In set by the control unit 5 expires (NO in step S306), the transmission unit 1 transmits radio waves to the normal target area An1 (step S308), or The receiving unit 2 receives a radio wave from the normal target area An1 (step S310).

  On the other hand, when the transmission period Ttn expires (YES in step S306), the control unit 5 stops the transmission of radio waves from the transmission unit 1 by stopping the power supply to the transmission unit 1 in the stop period Thn ( Step S312).

  Next, the detection unit 4 performs a detection process based on the radio wave received by the reception unit 2 in the transmission period Ttn (step S314).

  Next, when the object Tgt is detected as a result of the detection process (YES in step S316), the control unit 5 resets the count value Cnt to zero (step S318).

  Next, the control unit 5 continues to stop the transmission of radio waves from the transmission unit 1 by continuing to stop the power supply to the transmission unit 1 until the stop period Thn expires (step S320).

  Next, when the stop period Thn expires, the control unit 5 sets the next normal execution interval In (step S304).

  Further, when the target Tgt is not detected as a result of the detection process (NO in step S316), the control unit 5 increments the count value Cnt (step S322).

  Next, when the count value Ctn is smaller than the predetermined threshold value Thc (NO in step S324), the control unit 5 continues to stop power supply to the transmission unit 1 until the stop period Thn expires. The transmission of radio waves from the transmission unit 1 is continuously stopped (step S320).

  On the other hand, when the count value Ctn is equal to or greater than the predetermined threshold value Thc (YES in step S324), the control unit 5 switches from the normal detection mode to the enlargement detection mode (step S326).

  Next, the control unit 5 continues to stop the transmission of radio waves from the transmission unit 1 by continuing to stop the power supply to the transmission unit 1 until the stop period Thn in the normal detection process currently being executed expires. When the stop period Thn expires, the normal detection process is terminated and the enlargement detection process is started (step S328).

  The radio wave sensor according to the first embodiment of the present invention is configured to perform control to change the execution interval of the detection process based on the remaining amount of the battery B1 and the result of the detection process. It is not limited to. For example, the radio wave sensor may be configured to perform control to change the execution interval of the detection process based on the result of the detection process.

  Moreover, although the radio wave sensor according to the first embodiment of the present invention is configured to change the power supply stop period to the radio wave generator 31 and the power amplifier 33, the present invention is not limited to this. For example, the radio wave sensor may be configured to stop the power supply to the reception unit 2, the signal processing unit 3, and the detection unit 4 as a circuit for performing the detection process after the detection process in the stop period Th is completed. .

  In addition, the radio wave sensor according to the first exemplary embodiment of the present invention is configured to stop the power supply to the radio wave generation unit 31 and the power amplifier 33 during the stop period Th, but is not limited thereto. Absent. The radio wave sensor may be configured to supply power to the radio wave generation unit 31 and the power amplifier 33 during the stop period Th. This is because, for example, the power consumption in the radio wave generation unit 31 and the power amplifier 33 is larger when the radio wave is transmitted than when the radio wave is stopped. This is because power consumption is suppressed by the configuration in which the length of the period is changed.

  Moreover, although the radio wave sensor according to the first embodiment of the present invention is configured to detect the object Tgt in the target area according to the two-frequency CW method, the present invention is not limited to this. The radio wave sensor may be configured to detect the object Tgt in the target area according to a method other than the two-frequency CW method. Specifically, the radio wave sensor is, for example, an FM-CW (Frequency-Modulated Continuous-Wave) system described in Non-Patent Document 1 or Non-Patent Document 2, or a two-frequency ICW described in Non-Patent Document 3 ( The configuration may be such that the object Tgt in the target area is detected according to the Interrupted Continuous-Wave) method.

  By the way, for example, when the object identification device described in Patent Document 1 is installed in a place where the power that can be supplied is limited, if the power consumption in the object identification device exceeds the limit value, the object identification device There are times when it becomes difficult to operate the system stably. For this reason, there is a need for a radio wave sensor such as an object identification device that can operate with low power consumption.

  On the other hand, in the radio wave sensor according to the first embodiment of the present invention, the transmission units 1, 6 and 8 transmit radio waves to the target area. The receiving unit 2 receives radio waves from the target area. The detection unit 4 performs a detection process for detecting the object Tgt in the target area based on the radio wave received by the reception unit 2. The control units 5, 7, and 9 perform control to change the detection processing execution interval based on the result of the detection processing.

  With such a configuration, since the frequency of the detection process can be reduced within a range that does not adversely affect the result of the detection process, it is possible to correctly detect the object while suppressing power consumption by the detection process.

  Further, in the radio wave sensor according to the first embodiment of the present invention, the transmitters 1, 6 and 8 continuously transmit radio waves in the transmission period Tt, stop transmission of radio waves in the stop period Th, and transmit The period Tt and the stop period Th are alternately repeated. The control units 5, 7, and 9 change the execution interval by changing the length of the stop period Th based on the result of the detection process.

  In this way, with the configuration in which the length of the stop period Th with low power consumption is changed while maintaining the length of the transmission period Tt, power consumption can be suppressed while avoiding deterioration in the accuracy of detection processing. .

  Further, in the radio wave sensor according to the first embodiment of the present invention, whether or not the control units 5, 7, and 9 have transitioned from the state in which the object Tgt is not detected by the detection unit 4 to the detected state. The execution interval is shortened based on the result of the determination.

  With such a configuration, when the target object Tgt exists in the target area, the temporal transition of the detection result of the target object Tgt can be acquired with high accuracy. In addition, efficient detection processing can be performed with a configuration in which the frequency of detection processing is increased in a situation that requires high-frequency detection processing after the target Tgt is detected.

  Further, in the radio wave sensor according to the first embodiment of the present invention, whether or not the control units 5, 7, and 9 have transitioned from the state in which the object Tgt is detected by the detection unit 4 to the state in which the target Tgt is not detected. And the execution interval is lengthened based on the result of the determination.

  Thus, efficient detection processing can be performed by a configuration in which the frequency of detection processing is reduced in a situation where high-frequency detection processing is not required after the object Tgt is no longer detected.

  In addition, in the radio wave sensor according to the first embodiment of the present invention, the control units 5, 7 and 9 determine the range of the target area depending on whether or not a predetermined condition including a condition regarding the result of the detection process is satisfied. To change.

  With such a configuration, the range of the target area can be changed to an appropriate range according to the result of the detection process.

  In the radio wave sensor according to the first embodiment of the present invention, the control unit 5 changes the range of the target area by changing the transmission power of the transmission unit 1.

  With such a configuration, the range of the target area can be changed without using a mechanical operation, so that the mechanism of a transmitting device such as an antenna can be simplified.

  In the radio wave sensor according to the first embodiment of the present invention, the control unit 7 changes the directivity of the antenna in the transmission unit 6, specifically, the far-field transmission antenna 15 using the antenna switch 14. The range of the target area is changed by switching the normal transmission antenna 16.

  With such a configuration, it is possible to extend the reach of radio waves without increasing the transmission power of radio waves, and thus it is possible to suppress an increase in power consumption that accompanies a change in the range of the target area.

  In the radio wave sensor according to the first embodiment of the present invention, the control unit 9 changes the range of the target area by changing the direction of the tilt variable transmission antenna 18 in the transmission unit 8.

  With such a configuration, the beam direction of radio waves can be changed by a simple method, and the range of the target area can be flexibly changed.

  Further, in the radio wave sensor according to the first embodiment of the present invention, the control units 5, 7 and 9 change the execution interval by changing the stop period of power supply to the circuit for performing the detection process. To do.

  In this way, by stopping the circuit for performing the detection process in a period when the detection process is not performed, it is possible to suppress power consumption while changing the execution interval of the detection process.

  In the radio wave sensor according to the first embodiment of the present invention, the control units 5, 7 and 9 perform control to change the execution interval of the detection process based on the remaining amount of the battery B1 and the result of the detection process. Do.

  As described above, the configuration in which the frequency of the detection process is changed according to the remaining amount of the battery B1 can correctly detect the target Tgt while extending the time until the remaining amount of the battery B1 becomes zero. That is, the operation time of the radio wave sensor can be extended.

  Further, in the radio wave sensor according to the first embodiment of the present invention, the control units 5, 7 and 9 make a determination regarding the stop of the power supply based on the remaining amount of the battery B1.

  With such a configuration, the power consumption in the circuit can be changed according to the remaining amount of the battery B1, so that the time until the remaining amount of the battery B1 becomes zero can be extended. That is, the operation time of the radio wave sensor can be extended.

  Next, another embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

<Second Embodiment>
The present embodiment relates to a radio wave sensor that detects an object using a pulse method as compared with the radio wave sensor according to the first embodiment. The contents other than those described below are the same as those of the radio wave sensor according to the first embodiment.

[Configuration of radio wave sensor]
FIG. 24 is a diagram showing a configuration of a radio wave sensor according to the second embodiment of the present invention.

  Referring to FIG. 24, radio wave sensor 104 includes a transmission unit 301, a reception unit 302, a detection unit 304, and a control unit 5. The transmission unit 301 includes a transmission wave processing unit 310 and the transmission antenna 11. The receiving unit 302 includes a received wave processing unit 312 and the receiving antenna 13. The transmission antenna 11 and the reception antenna 13 are not limited to the configuration provided in the radio wave sensor 104, and may be provided outside the radio wave sensor 104.

  The operation of the control unit 5 is the same as that of the control unit 5 in the radio wave sensor 101 according to the first embodiment of the present invention shown in FIG. The operation of the transmission antenna 11 in the transmission unit 301 is the same as that of the transmission antenna 11 in the transmission unit 1 shown in FIG. The operation of the reception antenna 13 in the reception unit 302 is the same as that of the reception antenna 13 in the reception unit 2 shown in FIG.

  FIG. 25 is a diagram illustrating a configuration of a transmission wave processing unit in the transmission unit according to the second embodiment of the present invention.

  Referring to FIG. 25, transmission wave processing unit 310 includes a radio wave generation unit 61 and a power amplifier 33. The radio wave generator 61 includes a pulse generator 62, a mixer 63, and a local oscillator 64. The operation of the power amplifier 33 is the same as that of the power amplifier 33 in the transmission wave processing unit 10 shown in FIG.

  24 to 25, radio wave sensor 104 is a radio wave sensor using, for example, a pulse method. More specifically, the control unit 5 in the radio wave sensor 104 changes the transmission interval of the pulse radio wave group that is a group of pulse radio waves transmitted by the transmission unit 301 based on the result of the detection process.

[Set execution interval]
FIG. 26 is a diagram illustrating an example of the change of the operation mode by the radio wave sensor according to the second embodiment of the present invention. FIG. 26 shows an operation when the operation mode is switched from the normal detection mode to the enlargement detection mode at, for example, time (t3 + 68) milliseconds.

  FIG. 27 is a diagram illustrating an example of the change of the operation mode by the radio wave sensor according to the second embodiment of the present invention. FIG. 27 shows an operation when the operation mode is switched from the enlargement detection mode to the normal detection mode at, for example, time (t4 + 125) milliseconds.

  Referring to FIGS. 26 and 27, mode setting unit 84 in control unit 5 shown in FIG. 4 receives, for example, the number of times object non-detection information is continuously received from detection unit 304 at time (t3 + 68) milliseconds. When the threshold value Thc is exceeded, the operation mode is switched from the normal detection mode to the expansion detection mode at time (t3 + 68) milliseconds as shown in FIG.

  Further, for example, when the object setting information is received from the detection unit 304 at time (t4 + 125) milliseconds, the mode setting unit 84 changes the operation mode from the enlargement detection mode to normal at the time (t4 + 125) milliseconds as shown in FIG. Switch to detection mode.

  The execution interval setting unit 85 sets, for example, the detection processing execution interval, that is, the pulse group interval based on the operation mode and the remaining amount measurement result. Specifically, the execution interval setting unit 85 includes, for example, the remaining battery level. When the remaining amount measurement result indicates that there is little, the normal execution interval In of 100 milliseconds is set in the normal detection mode as shown in FIGS. 26 and 27, and the expansion execution of 4000 milliseconds is performed in the expansion detection mode. Set the interval Ie.

  For example, when the remaining amount measurement result indicates that the remaining battery level is sufficient, the execution interval setting unit 85 sets a normal execution interval In of 100 milliseconds in the normal detection mode, and in the expansion detection mode. An enlargement execution interval Ie of 2000 milliseconds is set.

  Further, for example, as shown in FIG. 26, the execution interval setting unit 85 detects that the operation mode is expanded from the normal detection mode at time (t3 + 68) milliseconds before the time corresponding to the normal execution interval In elapses from time t3. The following processing is performed when switching to the mode. That is, for example, the execution interval setting unit 85 newly sets the extended execution interval Ie from time t3 to time (t3 + 4100) milliseconds starting from time (t3 + 100) milliseconds when the time corresponding to the normal execution interval In elapses. To do.

  Further, for example, as shown in FIG. 27, the execution interval setting unit 85 normally detects the operation mode from the expansion detection mode at time (t4 + 125) milliseconds before the time corresponding to the expansion execution interval Ie elapses from time t4. The following processing is performed when switching to the mode. That is, for example, the execution interval setting unit 85 shortens the expansion execution interval Ie to the expansion execution interval Iei of 125 milliseconds at the switching time (t4 + 125) milliseconds, and starts the time (t4 + 225) milliseconds at the time (t4 + 225) milliseconds. A normal execution interval In up to seconds is newly set.

[Control of power supply]
For example, as shown in FIG. 26 and FIG. 27, the supply power interrupting unit 80 is an end timing at which a time Δt2 required for transmission of a pulse radio wave group including three pulse radio waves elapses from a start timing of a period based on the normal execution interval In. The power Pcn is supplied to the radio wave generation unit 61 and the power amplifier 33 in the transmission wave processing unit 310 until the power supply is stopped from the end timing to the next start timing.

  Further, for example, as shown in FIGS. 26 and 27, the supply power interrupting unit 80 ends the time Δt <b> 2 required for transmitting the pulse radio wave including three pulse radio waves from the start timing of the period based on the expansion execution interval Ie. The power Pce is supplied to the radio wave generation unit 61 and the power amplifier 33 in the transmission wave processing unit 310 until the timing, and the supply of power is stopped from the end timing to the next start timing.

  Therefore, for example, in the case shown in FIG. 26, the pulse radio wave group is transmitted from the transmission wave processing unit 310 via the transmission antenna 11 at every normal execution interval In until time (t3 + 100) milliseconds, and at time (t3 + 100) milliseconds. After the second, the pulse radio wave group is transmitted at every expansion execution interval Ie.

[Change target area range]
For example, as shown in FIGS. 26 and 27, the amplification factor control unit 81 sets the amplification factor of the power amplifier 33 to Gn in the period based on the normal execution interval In, and the power in the period based on the expansion execution interval Ie. The amplification factor of the amplifier 33 is set to Ge larger than Gn.

  Therefore, the pulse radio wave group is transmitted to the expansion target area Ae1 during the period based on the expansion execution interval Ie, and the pulse radio wave group is transmitted to the normal target area An1 during the period based on the normal execution interval In.

[Radio wave transmission processing]
Referring to FIG. 25 again, the transmission wave processing unit 310 in the transmission unit 301 repeatedly transmits the pulse radio wave group via the transmission antenna 11. Specifically, the radio wave generation unit 61 in the transmission wave processing unit 310 transmits a pulse radio wave group via the transmission antenna 11 at each execution interval according to the control of the control unit 5.

  FIG. 28 is a diagram illustrating an example of a pulse signal generated by the transmission unit and the reception unit according to the second embodiment of the present invention.

  Referring to FIG. 28, pulse generator 62 in radio wave generating unit 61 generates, for example, transmission pulse signals Pt1 to Pt3 having level Lpt and time width Δt1 at each execution interval as shown in FIGS. The generated transmission pulse signals Pt1 to Pt3 are output to the mixer 63. At this time, for example, the pulse generator 62 sets the interval between the transmission pulse signals Pt1 and Pt2 and the interval between the transmission pulse signals Pt2 and Pt3 to Tp.

  The time width Δt1 is appropriately set according to the distance from the radio wave sensor 104 to the target area, the measurement accuracy of the distance L, and the like. The interval Tp is determined based on the time until the transmitted radio wave is reflected by the target Tgt and returned.

  For example, the local oscillator 64 generates a carrier wave of 24 GHz and outputs the generated carrier wave to the mixer 63. The mixer 63 multiplies the transmission pulse signals Pt1 to Pt3 received from the pulse generator 62 and the carrier wave received from the local oscillator 64 to generate a group of transmission waves Txp1 to Txp3, respectively, and generates the generated transmission waves Txp1. ~ Txp3 is output to the power amplifier 33.

  For example, when the amplification factor is set to Gn by the amplification factor control unit 81, the power amplifier 33 amplifies the transmission waves Txp1 to Txp3 received from the mixer 63 with the amplification factor Gn, and the amplified transmission waves Txp1 to Txp3, respectively. It transmits to normal object area An1 via the transmission antenna 11. FIG. For example, when the amplification factor is set to Ge by the amplification factor controller 81, the power amplifier 33 amplifies the transmission waves Txp1 to Txp3 received from the mixer 63 with the amplification factor Ge, and the amplified transmission waves Txp1 to Txp3 Are transmitted to the enlargement target area Ae1 via the transmission antenna 11, respectively.

[Radio wave reception processing]
Referring to FIG. 24 again, receiving unit 302 receives radio waves from the target area. More specifically, the reception antenna 13 in the reception unit 302 receives the pulsed radio wave group generated when the target object Tgt in the target area reflects the transmission waves Txp1 to Txp3, that is, the reflected waves Rxp1 to Rxp3.

  FIG. 29 is a diagram illustrating a configuration of a reception wave processing unit in the reception unit according to the second embodiment of the present invention.

  Referring to FIG. 29, received wave processing unit 312 includes a low noise amplifier 41, a mixer 42, an IF amplifier 43, a local oscillator 46, and a detector 47. The operations of the low noise amplifier 41, the mixer 42, and the IF amplifier 43 in the reception wave processing unit 312 are the same as those of the low noise amplifier 41, the mixer 42, and the IF amplifier 43 in the reception wave processing unit 12 illustrated in FIG.

  The low noise amplifier 41 in the reception wave processing unit 312 amplifies the reflected waves Rxp 1 to Rxp 3 received by the reception antenna 13 and outputs the amplified waves to the mixer 42.

  For example, the local oscillator 46 generates a local signal of 24 GHz and outputs the generated local signal to the mixer 42. The mixer 42 multiplies the reflected waves Rxp1 to Rxp3 received from the low noise amplifier 41 by the local signal received from the local oscillator 46, thereby obtaining a frequency component of a difference between the frequency component of the local signal and the frequency components of the reflected waves Rxp1 to Rxp3. A sum frequency signal having the difference signal and the sum of both frequency components is generated.

  The IF amplifier 43 amplifies the difference signal of the difference signal and the sum frequency signal generated in the mixer 42 with a large amplification factor, and outputs the amplified difference signal to the detector 47.

  The detector 47 detects the differential signal received from the IF amplifier 43 to generate reception pulse signals Pr1 to Pr3 shown in FIG. 28, and outputs the generated reception pulse signals Pr1 to Pr3 to the detection unit 304.

[Detection processing]
FIG. 30 is a diagram illustrating a configuration of a detection unit in the radio wave sensor according to the second embodiment of the present invention.

  Referring to FIG. 30, detection unit 304 includes a time comparison unit 51, an intensity acquisition unit 52, a distance calculation unit 53, and a measurement result determination unit 54.

  The detection unit 304 performs detection processing for detecting the target object Tgt in the target area based on the radio wave received by the reception unit 302. More specifically, the detection unit 304 performs the detection process based on the reflected waves Rxp1 to Rxp3 received from the target area, for example, received by the reception unit 302.

  Specifically, the intensity acquisition unit 52 in the detection unit 304 acquires, for example, the levels Lpr1 to Lpr3 of the reception pulse signals Pr1 to Pr3 received from the detector 47 in the reception wave processing unit 312, that is, the intensity, and acquires the acquired intensity. Is output to the measurement result determination unit 54.

  After receiving the transmission pulse signals Pt1 to Pt3 from the transmission unit 301, the time comparison unit 51 calculates time differences β1 to β3 required to receive the reception pulse signals Pr1 to Pr3 from the detector 47, and calculates the calculated time differences β1 to β3. β3 is output to the distance calculation unit 53.

  The distance calculation unit 53 calculates the distance L based on the time differences β1 to β3 received from the time comparison unit 51. Specifically, the distance calculation unit 53 calculates, for example, the average of c × β1 / 2, c × β2 / 2, and c × β3 / 2 as the distance L, and outputs the calculation result to the measurement result determination unit 54. .

  The measurement result determination unit 54 detects the object Tgt in the target area based on the strength received from the strength acquisition unit 52 and the distance L received from the distance calculation unit 53.

  For example, when the measurement result determination unit 54 detects the target Tgt in the target area, the measurement result determination unit 54 outputs the target detection information to the control unit 5 and the signal control device 151. For example, when the target Tgt in the target area is not detected, the measurement result determination unit 54 outputs the target non-detection information to the control unit 5 and the signal control device 151.

  Note that the detection unit 304 acquires, for example, the moving speed of the target Tgt based on the time change of the distance L, and detects the target Tgt in the target area based on the acquired moving speed, intensity, and distance L. May be.

  Although the transmission unit according to the second embodiment of the present invention is configured to repeatedly transmit a group of pulse radio waves including three pulse radio waves, the present invention is not limited to this. For example, the transmission unit may be configured to repeatedly transmit one pulse radio wave, or may be configured to repeatedly transmit a group of pulse radio waves including two or four or more pulse radio waves.

[Variation 1 of the radio wave sensor 104]
FIG. 31 is a diagram showing a configuration of a modified example of the radio wave sensor according to the second embodiment of the present invention.

  Referring to FIG. 31, radio wave sensor 105, which is a modification of radio wave sensor 104 shown in FIG. 24, has transmission unit 306 and control unit 7 instead of transmission unit 301 and control unit 5 compared to radio wave sensor 104. Prepare.

  Compared with the transmission unit 301 shown in FIG. 24, the transmission unit 306 includes a far-field transmission antenna 15 and a normal transmission antenna 16 instead of the transmission antenna 11, and further includes an antenna switch 14. The far-field transmission antenna 15 and the normal transmission antenna 16 are not limited to the configuration provided in the radio wave sensor 105 but may be provided outside the radio wave sensor 105.

  The operations of the receiving unit 302 and the detecting unit 304 are the same as those of the receiving unit 302 and the detecting unit 304 shown in FIG. The operation of the control unit 7 is the same as that of the control unit 7 in the radio wave sensor 102 shown in FIG.

  The operations of the antenna switch 14, the far transmission antenna 15 and the normal transmission antenna 16 in the transmission unit 306 are the same as those of the antenna switch 14, the far transmission antenna 15 and the normal transmission antenna 16 in the transmission unit 6 shown in FIG. is there. The operation of transmission wave processing section 310 in transmission section 306 is the same as that of transmission wave processing section 310 in transmission section 301 shown in FIG. For example, a fixed value is set for the amplification factor of the power amplifier 33 in the transmission wave processing unit 310.

  FIG. 32 is a diagram illustrating an example of a change in operation mode according to a modification of the radio wave sensor according to the second embodiment of the present invention. FIG. 32 shows the operation when the operation mode is switched from the normal detection mode to the enlargement detection mode, for example, at time (t3 + 68) milliseconds, as in FIG. The time change of the level Lp of the transmission pulse signal shown in FIG. 32 is the same as the time change of the level Lp of the transmission pulse signal shown in FIG.

  FIG. 33 is a diagram illustrating an example of a change in operation mode according to a modification of the radio wave sensor according to the second embodiment of the present invention. FIG. 33 shows the operation when the operation mode is switched from the enlargement detection mode to the normal detection mode at, for example, time (t4 + 125) milliseconds, as in FIG. The time change of the level Lp of the transmission pulse signal shown in FIG. 33 is the same as the time change of the level Lp of the transmission pulse signal shown in FIG.

  Referring to FIGS. 31 to 33, antenna switching control unit 86 in control unit 7 shown in FIG. 13 switches antenna switch 14 in transmission unit 306 according to the type of execution interval, for example. The range of the target area is changed by changing the directivity.

  More specifically, for example, as shown in FIGS. 32 and 33, the antenna switching control unit 86 is configured to output the output terminal of the power amplifier 33 and the normal transmission antenna in the transmission wave processing unit 310 during a period based on the normal execution interval In. 16 is electrically connected. Therefore, during this period, for example, a pulse radio wave group having a predetermined power is transmitted from the normal transmission antenna 16 to the normal target area An1 shown in FIGS.

  Further, for example, as shown in FIGS. 32 and 33, the antenna switching control unit 86 electrically connects the output terminal of the power amplifier 33 and the far-field transmission antenna 15 in a period based on the expansion execution interval Ie. Therefore, in the period, for example, the pulse radio wave group of the predetermined power is transmitted from the distant transmitting antenna 15 to the enlargement target area Ae2 shown in FIG.

[Variation 2 of the radio wave sensor 104]
FIG. 34 is a diagram showing a configuration of a modification of the radio wave sensor according to the second embodiment of the present invention.

  Referring to FIG. 34, radio wave sensor 106, which is a modification of radio wave sensor 104 shown in FIG. 24, has transmission unit 308 and control unit 9 instead of transmission unit 301 and control unit 5 compared to radio wave sensor 104. Prepare.

  The transmission unit 308 includes the variable tilt transmission antenna 18 instead of the transmission antenna 11 as compared with the transmission unit 301 illustrated in FIG. 24. The variable tilt transmission antenna 18 is not limited to the configuration provided in the radio wave sensor 106, and may be provided outside the radio wave sensor 106.

  The operations of the receiving unit 302 and the detecting unit 304 are the same as those of the receiving unit 302 and the detecting unit 304 shown in FIG. The operation of the control unit 9 is the same as that of the control unit 9 in the radio wave sensor 103 shown in FIG.

  The operation of the variable tilt transmission antenna 18 in the transmission unit 308 is the same as that of the variable tilt transmission antenna 18 in the transmission unit 8 shown in FIG. The operation of the transmission wave processing unit 310 in the transmission unit 308 is the same as that of the transmission wave processing unit 310 in the transmission unit 301 shown in FIG. For example, a fixed value is set for the amplification factor of the power amplifier 33 in the transmission wave processing unit 310.

  FIG. 35 is a diagram illustrating an example of operation mode change according to a modification of the radio wave sensor according to the second embodiment of the present invention. FIG. 35 shows the operation when the operation mode is switched from the normal detection mode to the enlargement detection mode at time (t3 + 68) milliseconds, for example, as in FIG. The time change of the level Lp of the transmission pulse signal shown in FIG. 35 is the same as the time change of the level Lp of the transmission pulse signal shown in FIG.

  FIG. 36 is a diagram illustrating an example of operation mode change according to a modification of the radio wave sensor according to the second embodiment of the invention. FIG. 36 shows the operation when the operation mode is switched from the enlargement detection mode to the normal detection mode at, for example, time (t4 + 125) milliseconds, as in FIG. The time change of the level Lp of the transmission pulse signal shown in FIG. 36 is the same as the time change of the level Lp of the transmission pulse signal shown in FIG.

  34 to 36, the tilt angle control unit 87 in the control unit 9 shown in FIG. 17 switches, for example, the tilt angle of the tilt variable transmission antenna 18 in the transmission unit 308 according to the type of execution interval, and transmits. The range of the target area is changed by changing the direction of the antenna in the unit 308.

  Specifically, for example, as shown in FIG. 35 and FIG. 36, the tilt angle control unit 87 sets the tilt angle of the tilt variable transmission antenna 18 to αn during a period based on the normal execution interval In. The sex direction Dn is set so as to face the position Cn at the substantially center of the pedestrian crossing PC1 shown in FIGS.

  Therefore, for example, a pulse radio wave group having a predetermined power is transmitted from the variable tilt transmission antenna 18 having the tilt angle αn to the normal target area An1 shown in FIGS. 1 and 7 during the period.

  Further, for example, as shown in FIGS. 35 and 36, the tilt angle control unit 87 sets the tilt angle of the tilt variable transmission antenna 18 to αe during the period based on the enlargement execution interval Ie, thereby causing the directionality of the directivity. De is set so as to face the position Ce shown in FIGS.

  Therefore, for example, the pulse radio wave group of the predetermined power is transmitted from the variable tilt transmission antenna 18 having the tilt angle αe to the enlargement target area Ae1 shown in FIGS. 1 and 7 during the period.

  As described above, in the radio wave sensor according to the second embodiment of the present invention, the transmission units 301, 306, and 308 repeatedly transmit the pulse radio wave that is a pulsed radio wave. The control units 5, 7 and 9 change the execution interval by changing the transmission interval of the pulse radio wave based on the result of the detection process.

  As described above, with the configuration in which the transmission interval of the repeatedly transmitted pulse radio wave is changed according to the result of the detection process, it is possible to suppress power consumption while avoiding deterioration in the accuracy of the detection process.

  Note that some or all of the components and operations of the devices according to the first embodiment to the second embodiment of the present invention can be combined as appropriate.

  The above embodiment should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The above description includes the following features.

[Appendix 1]
A transmitter that transmits radio waves to the target area;
A receiving unit for receiving radio waves from the target area;
A detection unit that performs detection processing for detecting an object in the target area based on the radio wave received by the reception unit;
A control unit that performs control to change an execution interval of the detection process based on a result of the detection process;
The transmission unit transmits radio waves to the target area according to a two-frequency CW method or a pulse method,
The target area is a pedestrian crossing,
The object is a pedestrian,
The control unit is a radio wave sensor that switches between a normal execution interval and an enlarged execution interval longer than the normal execution interval based on a result of the detection process.

1, 6, 8, 301, 306, 308 Transmission unit 2,302 Reception unit 3 Signal processing unit 4,304 Detection unit 5, 7, 9 Control unit 10,310 Transmission wave processing unit 11 Transmission antenna 12,312 Reception wave processing Unit 13 Reception antenna 14 Antenna switch 15 Remote transmission antenna 16 Normal transmission antenna 18 Tilt variable transmission antenna 31 Radio wave generation unit 32 Directional coupler 33 Power amplifier 35 Frequency switching unit 36 Voltage generation unit 37 Voltage controlled oscillator 41 Low noise amplifier 42 Mixer 43 IF amplifier 44 Low pass filter 45 A / D converter 46 Local oscillator 47 Detector 51 Time comparison unit 52 Strength acquisition unit 53 Distance calculation unit 54 Measurement result judgment unit 61 Radio wave generation unit 62 Pulse generator 63 Mixer 64 Local oscillator 71 Buffer Control unit 72 Buffer 73 Second buffer 74 FFT processing unit 76 Spectrum analysis unit 77 Analysis result determination unit 80 Supply power interruption unit 81 Amplification rate control unit 82 General determination unit 83 Battery remaining amount measurement unit 84 Mode setting unit 85 Execution interval setting unit 86 Antenna switching Control unit 87 Tilt angle control unit 101, 102, 103, 104, 105, 106 Radio wave sensor 121 Power generation unit 151 Signal control device 161 Signal lamp for pedestrian 201 Signal control system B1 Battery

Claims (15)

A transmitter that transmits radio waves to the target area;
A receiving unit for receiving radio waves from the target area;
A detection unit that performs detection processing for detecting an object in the target area based on the radio wave received by the reception unit;
A control unit that performs control to change an execution interval of the detection process based on a result of the detection process ;
With a battery,
The said control part is a radio wave sensor which performs control which changes the execution space | interval of the said detection process based on the remaining amount of the said battery, and the result of the said detection process . A radio wave sensor,
A transmitter that transmits radio waves to the target area;
A receiving unit for receiving radio waves from the target area;
A detection unit that performs detection processing for detecting an object in the target area based on the radio wave received by the reception unit;
A control unit that performs control to change an execution interval of the detection process based on a result of the detection process;
The control unit changes the execution interval by changing a stop period of power supply to a circuit for performing the detection process,
The radio wave sensor further includes:
With a battery,
The control unit is a radio wave sensor that makes a determination on the stop of the power supply based on a remaining amount of the battery. The transmitter continuously transmits radio waves in a first period, stops transmitting radio waves in a second period, and alternately repeats the first period and the second period,
The radio wave sensor according to claim 1 or 2 , wherein the control unit changes the execution interval by changing a length of the second period based on a result of the detection process. The transmitter repeatedly transmits a pulse radio wave that is a pulse radio wave,
The radio wave sensor according to claim 1 or 2 , wherein the control unit changes the execution interval by changing a transmission interval of the pulse radio wave based on a result of the detection process. The control unit makes a determination as to whether or not the object has been detected from a state in which the object is not detected by the detection unit, and shortens the execution interval based on a result of the determination. The radio wave sensor according to any one of claims 1 to 4 . The control unit makes a determination as to whether or not the detection unit has made a transition from a state in which the object is detected to a state in which the target is not detected, and lengthens the execution interval based on the determination result. The radio wave sensor according to any one of claims 1 to 5 . The said control part changes the range of the said target area according to whether the predetermined condition including the conditions regarding the result of the said detection process is satisfy | filled, The any one of Claims 1-6 Radio wave sensor. The radio wave sensor according to claim 7 , wherein the control unit changes a range of the target area by changing transmission power of the transmission unit. The radio wave sensor according to claim 7 or 8 , wherein the control unit changes a range of the target area by changing a directivity of an antenna in the transmission unit. Wherein the control unit changes the range of the target area by changing the orientation of the antenna in the transmitting unit, a radio wave sensor according to any one of claims 7 to 9. The radio wave sensor according to any one of claims 1 to 10 , wherein the control unit changes the execution interval by changing a stop period of power supply to a circuit for performing the detection process. . A detection method in a radio wave sensor,
Transmitting radio waves to the target area;
Receiving radio waves from the target area;
Performing a detection process for detecting an object in the target area based on the received radio wave;
The detection based on the result of the process, viewing including the step of performing control to change the interval of the detection process,
The radio wave sensor includes a battery,
In the step of performing the control, a detection method of performing control for changing an execution interval of the detection process based on a remaining amount of the battery and a result of the detection process. A detection method in a radio wave sensor,
Transmitting radio waves to the target area;
Receiving radio waves from the target area;
Performing a detection process for detecting an object in the target area based on the received radio wave;
Performing control to change an execution interval of the detection process based on a result of the detection process,
In the step of performing the control, the execution interval is changed by changing a stop period of power supply to the circuit for performing the detection process,
The radio wave sensor includes a battery,
A detection method in which, in the step of performing the control, a determination is made regarding stopping of the power supply based on a remaining amount of the battery. A detection program used in a radio wave sensor that transmits radio waves to a target area and receives radio waves from the target area,
On the computer,
Performing a detection process for detecting an object in the target area based on the received radio wave;
A program for executing a step of performing control to change an execution interval of the detection process based on a result of the detection process ,
The radio wave sensor includes a battery,
In the step of performing the control, a detection program for performing control for changing an execution interval of the detection process based on a remaining amount of the battery and a result of the detection process . A detection program used in a radio wave sensor that transmits radio waves to a target area and receives radio waves from the target area,
On the computer,
Performing a detection process for detecting an object in the target area based on the received radio wave;
A program for executing a step of performing control to change an execution interval of the detection process based on a result of the detection process,
In the step of performing the control, the execution interval is changed by changing a stop period of power supply to the circuit for performing the detection process,
The radio wave sensor includes a battery,
In the step of performing the control, a detection program that makes a determination on the stop of the power supply based on the remaining amount of the battery.

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