JP2006209202A - Periphery monitoring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately grasp the movement of a traveling object (especially, person) to be monitored, and to accurately predict the intrusion of the traveling object to the interior of a vehicle C even under such an environment that a disturbance frequency is present, in monitoring the traveling object positioned in the periphery of the installation location of a Doppler sensor 1 by using the Doppler sensor 1. <P>SOLUTION: In such a case that at least one band width excluding band width including the maximum frequency and minimum frequency in a predetermined frequency range among all band widths whose frequency levels are calculated on the basis of FFT analysis by an FFT analyzing part 13 is specific band width whose frequency level is a first set level or more, when the frequency levels of two band widths adjacent to the high side and low side of a frequency for the specific band width are the second set level which is lower than the first set level or lower, the frequency level of the specific band width is lowered by a disturbance frequency removing part 14. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a peripheral monitoring device that uses a Doppler sensor to monitor the movement of a moving object located around the installation position of the Doppler sensor and predicts the intrusion of the moving object into a vehicle cabin. Belonging to.

2. Description of the Related Art Conventionally, as a device for detecting the intrusion of a vehicle into a passenger compartment, a device that determines an abnormality when the vehicle door is opened and performs an alarm or the like is well known. Further, as disclosed in, for example, Patent Document 1, there is a device that detects an intrusion of a person into the passenger compartment by using a Doppler shift that occurs when a person enters the passenger compartment.
JP 2004-181982 A

  However, in the conventional intrusion detection device, since it can be gradually detected after a person has entered the vehicle compartment, it is often too late.

  Therefore, it is considered to further advance the idea of Patent Document 1 and predict the intrusion of a moving object such as a person in advance by a Doppler sensor, and take a countermeasure such as issuing an alarm when an intrusion is predicted. It is done. This Doppler sensor emits a transmission wave such as a microwave, receives a reflected wave formed by reflecting the transmission wave on an object, and shifts the frequency of the transmission wave and the reflected wave (according to the moving speed of the object). Change in response) as a signal. Then, by performing FFT analysis on the output signal from the Doppler sensor, a frequency level is obtained for each bandwidth obtained by dividing a predetermined frequency range into a predetermined number of constant frequency widths, and based on the frequency level of the bandwidth. The movement of the moving object will be monitored.

  However, the Doppler sensor is easily affected by the light of a fluorescent lamp emitting a specific frequency, and such a frequency becomes a disturbance frequency for the Doppler sensor, and the frequency level of the bandwidth including the frequency is considerably high. turn into. As a result, there is a high possibility that intrusion prediction will be inaccurate. Especially before a person invades the passenger compartment, many of the transmitted waves are reflected by objects other than humans, so these exist as noise, so even in an environment where there is no disturbance frequency as described above In the situation where it is originally difficult to accurately grasp the movement of a person, the presence of a disturbance frequency under such a situation makes the prediction of intrusion even more inaccurate.

  The present invention has been made in view of such points, and an object of the present invention is to monitor the movement of a moving object located around the installation position of the Doppler sensor using the Doppler sensor as described above. In such a case, even in an environment where disturbance frequencies exist, it is possible to accurately grasp the movement of a moving object (especially a person) to be monitored, and to accurately intrude the moving object into the vehicle cabin. It is to be able to predict.

  In order to achieve the above object, according to the present invention, at least one of all bandwidths whose frequency levels are obtained by FFT analysis, excluding a bandwidth including the maximum and minimum frequencies in a predetermined frequency range, is set as the first setting. In the case of a specific bandwidth having a frequency level equal to or higher than the level, both of the frequency levels of two bandwidths adjacent to the specific bandwidth on the high frequency side and the low frequency side are higher than the first setting level. Is lower than the second set level, the frequency level of the specific bandwidth is lowered.

  Specifically, in the first aspect of the present invention, the frequency level is obtained for each bandwidth obtained by dividing the predetermined frequency range into a predetermined number of constant frequency widths by performing FFT analysis on the output signal from the Doppler sensor. The present invention is directed to a periphery monitoring device that monitors the movement of a moving object located around the installation position of the Doppler sensor based on the frequency level of the bandwidth.

  A specific band in which at least one of all the bandwidths whose frequency levels are obtained by the FFT analysis, excluding the bandwidth including the maximum and minimum frequencies in the predetermined frequency range, is a frequency level equal to or higher than the first set level. In the case of the width, the frequency levels of the two adjacent bandwidths adjacent to the high frequency side and the low frequency side with respect to the specific bandwidth are both equal to or lower than the second setting level lower than the first setting level. In this case, it is assumed that correction means for reducing the frequency level of the specific bandwidth is provided.

  That is, when there is no moving object in an environment where a disturbance frequency exists, only the frequency level of the bandwidth including the disturbance frequency is considerably higher than the other bandwidths. If the frequency level of two adjacent bandwidths adjacent to the high frequency side and the low frequency side with respect to the specific bandwidth as the frequency level are equal to or lower than the second setting level lower than the first setting level, the specification The bandwidth can be recognized as a bandwidth including a disturbance frequency. On the other hand, when there is a moving object, even if a disturbance frequency exists, the frequency level of the adjacent bandwidth is as high as the frequency level of the specific bandwidth. If it is larger than the set level, it can be recognized as a moving object. Further, even when there are a plurality of disturbance frequencies, there is usually a certain frequency difference between the disturbance frequencies, and the adjacent bandwidth hardly becomes a specific bandwidth due to the plurality of disturbance frequencies. By comparing the specific bandwidth with the frequency level of the adjacent bandwidth, the bandwidth including all disturbance frequencies can be accurately identified. Since the frequency level of the specific bandwidth is lowered by the correcting means, the influence of the disturbance frequency is eliminated, and the movement of the moving object to be monitored can be accurately grasped.

  In the invention of claim 2, in the invention of claim 1, the correction means is configured to set the frequency level of the specific bandwidth to the average value of the frequency levels of two adjacent bandwidths.

  As a result, the frequency level of the specific bandwidth is set to substantially the same level as the normal noise level, and the movement of the moving object to be monitored can be grasped more accurately.

  According to a third aspect of the invention, in the first or second aspect of the invention, the Doppler sensor is installed in a vehicle interior of the vehicle, and monitors the movement of the moving object located around the vehicle to detect the moving object. It is assumed that the vehicle is predicted to enter the passenger compartment.

  That is, it is difficult to predict the disturbance frequency in advance because the vehicle does not know where to stop, but in the present invention, even if the disturbance frequency cannot be predicted in advance, the influence of the disturbance frequency is eliminated and monitoring is performed. It is possible to accurately grasp the movement of the moving object to be performed, and to effectively use the present invention. And before a person invades a vehicle interior, the intrusion can be accurately predicted beforehand.

  As described above, according to the periphery monitoring device of the present invention, when there is a specific bandwidth whose frequency level is equal to or higher than the first set level, the frequency is higher and lower than the specific bandwidth. When the frequency levels of two adjacent bandwidths that are adjacent to each other are both equal to or lower than a second setting level that is lower than the first setting level, the frequency level of the specific bandwidth is reduced, thereby causing disturbance. By eliminating the influence of the frequency, it becomes possible to accurately grasp the movement of the moving object to be monitored, and to accurately predict the intrusion of the moving object into the vehicle interior of the vehicle.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a configuration of a periphery monitoring device according to an embodiment of the present invention. This periphery monitoring device receives a Doppler sensor 1 and an output signal from the Doppler sensor 1, and is abnormal or normal. It is comprised with the controller 11 which performs control which act | operates LED etc. in order to perform warning and to perform an alarm if it is abnormal.

  The Doppler sensor 1 has a dielectric transmitter 2 and emits a transmission wave with a frequency fs (24-GHz microwave in this embodiment) from a transmission antenna 3 and the transmission wave is reflected by an object. The received reflected wave is received by the receiving antenna 4. The frequency fo of the reflected wave changes according to the moving speed of the object. The Doppler sensor 1 then outputs a frequency shift amount | fs-fo | between the transmission wave and the reflected wave as a signal (an analog signal composed of an offset voltage) by the Schottky barrier diode 5. It is possible to detect the moving object and to know the moving speed.

  As shown in FIG. 2, the Doppler sensor 1 has a vehicle width direction center portion in an instrument panel 21 (made of a material that allows microwaves) provided at a front end of a vehicle C (automobile). The range surrounded by the alternate long and short dash line on the vehicle rear side of the installation position, that is, the range surrounding the vehicle compartment and the side and rear of the vehicle C (range within about 1 m from the vehicle C) is the detection range of the moving object It is said.

  The output signal from the Doppler sensor 1 is input to the amplifier 9 and amplified, and then input to the A / D converter 12 provided in the controller 11. The analog signal is digitally converted by the A / D converter 12. The signal is converted into a signal, and this digital signal is input to the FFT analysis unit 13.

  The FFT analysis unit 13 performs an FFT analysis on the output signal from the Doppler sensor 1 to obtain a frequency level for each bandwidth obtained by dividing a predetermined frequency range into a predetermined number of constant frequency widths. In the present embodiment, since a person is assumed as a moving object, 0 to 126 Hz is sufficient as the predetermined frequency range. The constant frequency width is 2 Hz, and the frequency levels of 63 bandwidths are obtained. The constant frequency width is preferably as small as 1 Hz from the viewpoint of reliably eliminating the influence of the disturbance frequency as will be described later, but in this embodiment, 2 Hz is taken into account in consideration of the processing capability and calculation speed of the controller 11. (The disturbance frequency can be sufficiently eliminated in this way).

  For example, when a person approaches and stops from the side door of the vehicle C from the side of the vehicle C and moves away from the side door, the frequency level of the bandwidth changes as shown in FIGS. That is, in FIG. 3 (a), it is shortly after the detection range is entered, and as the person approaches the vehicle C from there, as shown in FIGS. 3 (b) and 3 (c), the frequency is particularly high. The frequency level of multiple bandwidths, including slightly lower frequencies, rises from the center of the range, and as a result, the sum of the frequency levels of all bandwidths (the total amount of energy within a given frequency range) also increases. To go. Then, when a person stops closest to the vehicle C, as shown in FIG. 3D, the frequency level of the bandwidth decreases, and accordingly, the sum of the frequency levels of the entire bandwidth also decreases. . The frequency level at this time is a noise level close to a normal level. Subsequently, when a person moves away from the area, as shown in FIG. 3 (e), the frequency level of the bandwidth rises to the same level as when approaching, and eventually the person moves outside the detection range. As shown in 3 (f), the frequency level of the bandwidth decreases.

  Here, when there is a specific frequency that is a disturbance frequency with respect to the Doppler sensor 1 (for example, light of a fluorescent lamp of 50 Hz or 60 Hz) and there is no moving object, FIG. As shown in FIG. 4, only the frequency level of the bandwidth including the disturbance frequency (there are three in FIG. 4) is higher than the first set level, and the frequency levels of the other bandwidths are the first level. Is lower than the second set level, which is lower than the set level (frequency levels of other bandwidths are normal noise levels). Therefore, a specific band in which at least one of all the bandwidths whose frequency levels are obtained by the FFT analysis, excluding the bandwidth including the maximum and minimum frequencies in the predetermined frequency range, is a frequency level equal to or higher than the first set level. In the case of the width, the frequency levels of two adjacent bandwidths adjacent to the high frequency side and the low frequency side with respect to the specific bandwidth are both equal to or lower than the second setting level lower than the first setting level. If so, the specific bandwidth can be recognized as a bandwidth including a disturbance frequency. On the other hand, if there is a moving object (person), the frequency level of the adjacent bandwidth is as high as the frequency level of the specific bandwidth even if there is a disturbance frequency. If it is larger than the second setting level, it can be recognized as a moving object.

  The analysis result in the FFT analysis unit 13 is input to the disturbance frequency removing unit 14, and the disturbance frequency removing unit 14 removes the disturbance frequency. That is, when the specific bandwidth exists, the frequency levels of two adjacent bandwidths adjacent to the specific bandwidth on the high frequency side and the low frequency side are both equal to or lower than the second set level. If the frequency levels of the two adjacent bandwidths are both equal to or lower than the second set level, the frequency level of the specific bandwidth is lowered. As a result, the disturbance frequency removing unit 14 constitutes a correcting unit that reduces the frequency level of the specific bandwidth. In the present embodiment, the frequency level of the specific bandwidth is set to the average value of the frequency levels of the two adjacent bandwidths. Thereby, the disturbance frequency can be lowered to a normal noise level, and the influence of the disturbance frequency can be eliminated. Note that the frequency level of the specific bandwidth may be set to a constant level (including 0) instead of setting the average value of the frequency levels of two adjacent bandwidths.

  The analysis result in the FFT analysis unit 13 is input to the abnormality / normality determination unit 15 after the disturbance frequency is removed by the disturbance frequency removal unit 14. The abnormality / normality determination unit 15 calculates the sum of the frequency levels of all the bandwidths every predetermined time (the first predetermined time and the second predetermined time longer than the first predetermined time), and A reference level (that is, noise level) is set based on the calculated sum. An abnormal level is set by adding a predetermined level to the reference level. In the present embodiment, as will be described in detail later, three abnormal levels (first to third abnormal levels) having different levels are set. Then, it is determined whether it is abnormal or normal by comparing the calculated sum with the abnormal level. Thus, the abnormality / normality determination unit 15 calculates the sum of the frequency levels of all the bandwidths every predetermined time, and the reference level for setting the reference level based on the sum calculated by the calculator A setting means; an abnormality level setting means for setting an abnormal level by adding a predetermined level to a reference level; and a determination means for determining whether the abnormality is normal or not by comparing the sum and the abnormal level. Configure. Note that the total sum calculated every predetermined time is stored in the memory. The determination result in the abnormality / normality determination unit 15 is also stored in the memory.

  The determination result (the contents of the memory) in the abnormality / normality determination unit 15 is output to the signal output control unit 16, and the signal output control unit 16 determines the determination result, the sum (maximum value), the abnormality level, and the like. In accordance with the relationship, control is performed to turn on the LED, to give an alarm by voice, or to report that there is an abnormality in the portable device possessed by the user of the vehicle C, as will be described later.

  The peripheral monitoring device is provided with an abnormal level change dial switch for changing the abnormal level and a cancel switch for preventing an alarm by voice. The abnormal level change dial switch With the dial operation amount, the user of the vehicle C can change the abnormal level (particularly the first abnormal level) to a desired level (however, the maximum change amount is limited), and by operating the cancel switch, Even if it is determined that there is an abnormality, it is possible not to perform an alarm by voice.

  When the user of the vehicle C stops the vehicle C and leaves the vehicle C, if a keyless locking switch for locking the door of the vehicle C is operated, the start signal is turned on, and the start signal is turned on. After the elapse of t1 time (a time during which the user of the vehicle C can sufficiently go out of the detection range (for example, 10 seconds)), the Doppler sensor 1 starts to be turned on and immediately after the start of the operation. During t2 time (for example, 10 seconds), the abnormality / normality determination unit 15 sums the frequency levels of all the bandwidths every first predetermined time (as described above, the frequency level of the specific bandwidth is two adjacent bandwidths). Is added as an average value of the frequency levels of the two), and the sum of the numbers obtained during the time t2 is averaged, and this average value is set as the first reference level. After the bell is set, the movement of a moving object (person) located around the position where the Doppler sensor 1 is installed (around the vehicle C) is monitored to predict the intrusion of the moving object into the vehicle interior of the vehicle C. become. On the other hand, when a keyless unlocking switch for unlocking the door of the vehicle C is operated, the start signal is turned off and monitoring is stopped.

  The abnormality / normality determination unit 15 sets first to third abnormality levels having different levels as the abnormality level. For example, as shown in FIG. 3B, the first abnormal level is a level at which a person is approaching the vehicle C, and is the lowest level among the first to third abnormal levels. For example, as shown in FIG. 3C, the second abnormal level is a level at which a person approaches a position where the person can look into the vehicle interior with respect to the vehicle C, and is the second highest level. The third abnormal level is a level at which a person has entered the passenger compartment of the vehicle C, and is the highest level.

  Then, the abnormality / normality determination unit 15 exceeds the first abnormality level and exceeds the first abnormality level before the first set time T1 (for example, 6 seconds) has elapsed since the sum calculated at every predetermined time exceeds the first abnormality level. When it becomes below the first abnormality level, it is determined that there is an abnormality. That is, a person who tries to enter the vehicle interior of the vehicle C usually approaches the vehicle C considerably, stops after approaching, and looks into the vehicle interior. Accordingly, since the movement of the person changes as shown in FIGS. 3A to 3D, the sum is not less than the first abnormality level after the first set time T1 after exceeding the first abnormality level. It becomes as follows. At this time, the abnormality / normality determination unit 15 determines that it is abnormal (intrusion is predicted or the possibility of intrusion is high).

  After determining that there is an abnormality, the signal output control unit 16 issues a warning by voice, or reports that the portable device has an abnormality in addition to performing a warning by voice. That is, when the total sum exceeds the first abnormality level and is less than or equal to the third abnormality level between the time when the sum exceeds the first abnormality level and becomes less than or equal to the first abnormality level. Performs a voice alarm for about 5 seconds, for example, but does not perform notification to the portable device. On the other hand, when the maximum value of the sum exceeds the third abnormal level, it is determined that there is a high possibility that the vehicle has already entered the vehicle interior, and both a warning by voice and a notification to the portable device are performed. Then, the signal output control unit 16 is abnormal by the abnormality / normality determination unit 15 while the sum exceeds the first abnormality level (except when it is determined to be normal as described later). Even if it is not determined, the LED is blinked and threatened with light so that no one approaches. When the maximum sum exceeds the second abnormality level between the time when the sum exceeds the first abnormality level and falls below the first abnormality level, a voice alarm and a portable device are sent. Both of the notifications may be performed.

  On the other hand, when the sum does not exceed the first abnormality level before the determination that the abnormality is present, or since the sum exceeds the first abnormality level and exceeds the first abnormality level, the first abnormality level is exceeded. When the set time T1 elapses, the sum is continuously greater than or equal to the second set time T2 (e.g., about the same as T1) after the determination that the abnormality is not lower than the first abnormality level. When it does not exceed the first abnormality level, it is determined that it is normal.

  Here, before the determination that the abnormality is present, when the sum does not exceed the first abnormality level, or after the determination that the abnormality is present, the sum continues for a second set time T2 or more. When the first abnormal level is not exceeded, the predetermined time that is the interval for calculating the sum is made longer (second predetermined time (for example, about 1 second)) than when the first abnormal level is exceeded. That is, the Doppler sensor 1 is intermittently operated, and the calculation interval is increased accordingly. Even if it does in this way, since it is at the time of determination that it is normal, a problem does not arise in particular. In addition, the operating current of the Doppler sensor 1 can be reduced and the power consumption can be reduced. When the sum exceeds the first abnormal level, the Doppler sensor 1 is continuously operated, and the predetermined time is shortened to the first predetermined time.

  Further, before the determination that the abnormality is present, when the sum does not exceed the first abnormality level, or after the determination that the abnormality is present, the sum continues for a second set time T2 or more. When the first abnormal level is not exceeded, the reference level is updated at a predetermined timing to a new reference level set based on a plurality of sums not calculated exceeding the first abnormal level. For example, at the timing when the sum is calculated 10 times, an average value of the 10 sums (except for those not satisfying a certain condition as described later) is obtained, and the average value is set as a new reference level. At this time, the sum that is not within the predetermined level range including the current reference level is not used for setting a new reference level. This is because the reference level is accurately obtained by excluding data such as when suddenly large noise occurs. If the sum does not exceed the first abnormal level as it is, the average value of the ten sums is obtained again at the timing when the sum is calculated 10 times, and the average value is set as a new reference level. In this embodiment, when the difference between the new reference level and the current reference level is equal to or greater than a predetermined value (especially when the new reference level is higher than the reference level by a predetermined value), the reference level is updated. Do not update to a new standard level. This is because there is a person around the vehicle C and the above average value may have increased, and it cannot be determined that the person is just a passerby and is abnormal, but the person needs to be monitored. Because there is. That is, if the reference level is increased, it may not be determined that there is an abnormality, so the reference level is not updated.

  In addition, when the total exceeds the first abnormality level and does not exceed the first abnormality level, the reference level is set to the above-described reference level when the first set time T1 elapses and does not fall below the first abnormality level. Update to a new reference level set based on the sum calculated within the first set time T1 (in this case, update regardless of the difference between the new reference level and the current reference level). That is, when the sum exceeds the first abnormal level for the first set time T1 or more, the person does not stop because he approaches the vehicle C and looks into the vehicle interior, but is affected by the radio wave of the mobile phone or the like. It is determined that the noise level has increased, and the reference level is updated to the higher level. Also at this time, for example, an average value of a plurality of sums calculated within the first set time T1 may be obtained, and the average value may be set to a new reference level. As the reference level is updated, the first to third abnormal levels rise, so that the sum does not exceed the first abnormal level, and it is determined that the normal level is normal. As a result, the Doppler sensor 1 is intermittently operated.

  On the other hand, when the sum exceeds the first abnormal level, the reference level is not updated until it is determined that the sum is normal. This is because, when the sum exceeds the first abnormal level, it is highly likely that it is determined to be abnormal, but if the reference level is updated at this stage, it is determined to be abnormal. This is because there is a possibility that will not be made.

  Next, the basic control operation of the controller will be described based on the flowchart of FIG.

  First, in the first step S1, it is determined whether the start signal is in an ON state or an OFF state. If the result of this determination is that it is in an ON state, the process proceeds to step S2. The operation of S1 is repeated.

  In step S2, the initial setting operation is performed and the LEDs are blinked from the time when the start signal is turned on until the time t1 elapses. For this initial setting, specifically, according to the operation amount of the abnormal level change dial switch, a predetermined level to be added to the reference level when setting the abnormal level is changed and set according to the state of the cancel switch. Then, set to an alarm mode that performs a voice alarm when it is determined to be abnormal, or set to an alarm-free mode that does not perform a voice alarm. Further, the operating state mode is set to “0”. This operation state mode is set to “1” when the Doppler sensor 1 is in the intermittent operation state, and is set to “2” when the Doppler sensor 1 is in the continuous operation state. During this time, it is set to “0” in this way (Doppler sensor 1 is in a continuous operation state during this period), and once the FFT analysis / determination process (step S4) described later is performed once, then Doppler sensor 1 It is set to “1” or “2” in accordance with the operating state.

  In the next step S3, the state of the start signal is determined again, and if the result of this determination is that it is in the ON state, the process proceeds to step S4, while if it is in the OFF state, the process returns to step S1.

  In step S4, the FFT analysis unit 13, disturbance frequency removal unit 14, and abnormality / normality determination unit 15 perform FFT analysis / determination processing described in detail later. In the next step S5, the signal output control unit 16 Depending on the determination result in the FFT analysis / determination process and the relationship between the total (maximum value) of the frequency levels of all bandwidths and the abnormal level, the LED is turned on, a voice alarm is given, or the portable device is abnormal. Control to notify that there was.

  In the next step S6, the operation state mode is determined. When the operation state mode is “1”, the process proceeds to step S7. When the operation state mode is “2”, the process returns to step S3.

  In step S7, the ON / OFF state of the start signal is determined. When the start signal is in the ON state, the process proceeds to step S8. When it is in the OFF state, the process returns to step S1.

  In step S8, the FFT analysis / determination process is performed in the same manner as in step S4. In the next step S9, the operating state mode is determined. When the operating state mode is “1”, the process proceeds to step S7. On the other hand, when the operating state mode is “2”, the process returns to step S3.

  Specifically, the FFT analysis / determination process in step S4 or S8 is as shown in FIG.

  That is, in step S101, the output signal from the Doppler sensor 1 is input, and in the next step S102, the FFT analysis unit 13 performs FFT analysis on the output signal from the Doppler sensor 1, thereby setting a predetermined frequency range to a predetermined number. A frequency level is obtained for each bandwidth divided by a certain frequency width.

  In the next step S103, the disturbance frequency removing unit 14 performs a disturbance frequency removing process. Specific processing of this disturbance frequency removal processing is shown in FIG. This disturbance frequency removal process is sequentially performed for each bandwidth except for the bandwidth including the maximum and minimum frequencies in the predetermined frequency range.

  That is, in step S201, it is determined whether or not the frequency level of the bandwidth is equal to or higher than the first setting level X. When this determination is YES (when the bandwidth is a specific bandwidth). On the other hand, when the determination is NO (when the bandwidth is not the specific bandwidth), the process proceeds to step S204.

  In step S202, it is determined whether the frequency levels of the two adjacent bandwidths adjacent to the higher and lower frequencies with respect to the bandwidth are equal to or lower than the second setting level Y. If YES, the process proceeds to step S203, and then proceeds to step S204. If the determination is NO, the process proceeds to step S204 as it is.

  In step S203, the frequency level of the bandwidth is corrected. That is, as described above, the frequency level of the bandwidth is set to the average value of the frequency levels of two adjacent bandwidths.

  In step S204, it is determined whether or not the processing in steps S201 to S203 has been completed for all the bandwidths. If this determination is NO, the process returns to step S201 and the processing in steps S201 to S203 is performed for the next bandwidth. While the process is repeated, when the determination is YES, the disturbance frequency removal process is terminated.

  This disturbance frequency removal process eliminates the influence of disturbance frequencies such as fluorescent light, and the abnormality / normality determination unit 15 can accurately determine whether it is abnormal or normal. .

  Returning to the flowchart of FIG. 6, in the next step S <b> 104, the abnormality / normality determination unit 15 performs a reference level calculation process. Specific processing of this reference level calculation processing is shown in FIG.

  That is, in step S301, the operation state mode is determined. When this operation state mode is “0”, the process proceeds to step S302, and data for N1 times (the number of times calculated within t2 time) (in this reference level calculation process, the sum of the frequency levels of all the bandwidths). (Referred to as data) is set as the reference level, and thereafter the reference level calculation process is terminated.

  When the operation state mode is “1”, the process proceeds to step S303, and the average value of only the data satisfying a certain condition among the data for N2 times (for example, 10 times) is set as a new reference level. To do. The data satisfying the certain condition is data within the predetermined level range including the current reference level. That is, as described above, data that is not within a predetermined level range including the current reference level (data when suddenly large noise occurs) is not used for setting a new reference level. In this way, the reference level is updated to a new reference level, and thereafter the reference level calculation process is terminated.

  Further, when the operation state mode is “2”, the process proceeds to step S304 to determine whether or not the first set time T1 has elapsed since the data exceeded the first abnormal level, and this determination is YES. In some cases, the process proceeds to step S305, whereupon the reference level calculation process ends. On the other hand, if the determination is NO, the process proceeds to step S306, and then the reference level calculation process ends.

  In step S305, the average value of the data for N3 times (the number of times calculated within T1 time) is set to a new reference level and updated to this new reference level. On the other hand, in step S306, the reference level is left as it is and is not updated.

  Returning to the flowchart of FIG. 6 again, in the next step S105, the abnormality / normality determination unit 15 performs an abnormality / normality determination process, and thereafter ends the FFT analysis / determination process.

  Specifically, the abnormality / normality determination process is performed as shown in FIG. That is, in step S401, the predetermined level (changed according to the operation amount of the abnormal level change dial switch) is added to the set reference level to set the abnormal level (first to third abnormal levels). By comparing the sum of the frequency levels of all the bandwidths with the abnormal level, it is determined whether it is abnormal or normal, and this determination result is stored in the memory.

  In the next step S402, it is determined whether or not the alarm present mode is set or the alarm no mode is set. If the alarm no mode is set, the process proceeds to step S403, and then step S405. On the other hand, when the warning mode is set, the process proceeds to step S404, and then proceeds to step S405.

  In step S403, the maximum value of the sum of the frequency levels of all bandwidths is only stored in the memory, and the contents of the memory are not output to the signal output control unit 16. On the other hand, in step S404, the contents of the memory are output to the signal output control unit 16.

  In step S405, it is determined whether an OFF signal of the mobile phone is detected. If the determination is YES, the process proceeds to step S406 to initialize (reset) the memory, and then determine whether there is an abnormality / normality. On the other hand, when the determination is NO, the abnormality / normality determination process is ended as it is. Note that the determination in step S404 is made based on whether or not the sum of the frequency levels of all the bandwidths has decreased by a certain level or more within a certain time. That is, when the mobile phone is in the ON state, the sum of the frequency levels of the entire bandwidth is increased by the radio wave, and when the mobile phone is in the OFF state, the sum of the frequency levels of the entire bandwidth is rapidly reduced, When the sum of the frequency levels of all the bandwidths falls below a certain level, it is determined that the mobile phone OFF signal has been detected.

  Next, a basic example of the operation of the periphery monitoring device will be described based on the time chart of FIG.

  First, when the user of the vehicle C operates the keyless locking switch and the start signal is turned on, after the elapse of t1 time from the time when this state is turned on, the Doppler sensor 1 starts to be turned on and operates. During the time t2 from the start, the sum of the frequency levels of all the bandwidths is calculated every predetermined time (first predetermined time), and the above total of the number (N1) obtained during the time t2 is averaged. This average value is set as the first reference level. In FIG. 10, the first reference level is set to A.

  Note that the user completely leaves the detection range of the Doppler sensor 1 during the time t1.

  After the elapse of time t2, the movement of a moving object (person) located around the installation position of the Doppler sensor 1 (around the vehicle C) is monitored. In FIG. 10, since the sum calculated every predetermined time does not exceed the first abnormality level set based on the reference level (and the operation amount of the abnormality level change dial switch), it is determined to be normal. At this time, the Doppler sensor 1 is in an intermittent operation state, and the predetermined time that is the sum calculation interval is the second predetermined time. Then, at the timing when the total sum is calculated N2 times, an average value of the N2 totals (excluding those outside the predetermined level range) is obtained, and the average value is set and updated to a new reference level. In FIG. 10, the reference level is updated in order of B and C (by updating the reference level, the “reference level”, “first” in the column “change in the sum of frequency levels of all bandwidths” in FIG. The level such as “1 abnormal level” changes, but the amount of change in the reference level is small, so it is not changed in FIG.

  In FIG. 10, after the reference level is updated to C, the sum exceeds the first abnormal level. As a result, the LED blinks. In addition, the Doppler sensor 1 is in a continuous operation state, and a predetermined time that is the calculation interval of the sum is a first predetermined time. The reference level remains C without being updated.

  Then, after the sum exceeds the first abnormal level, it becomes equal to or lower than the first abnormal level before the lapse of T1 time. The maximum value of the sum total during this period exceeds the first abnormality level and is not more than the third abnormality level. Thereby, it determines with it being abnormal and an audio | voice warning is performed. However, it will not be done until the report to the mobile device.

  After the determination that the abnormality is present, the sum exceeds the first abnormality level again before T2 time elapses. This causes the LED to flash again. Then, when the sum exceeds the first abnormal level, it becomes equal to or lower than the first abnormal level before the time T1 elapses, and it is determined that there is an abnormality, and a sound alarm is performed. Since the maximum value of the sum at this time also exceeds the first abnormality level and is equal to or less than the third abnormality level, the notification to the portable device is not performed. After that, during the abnormality alarm, when the sum exceeds the first abnormality level and exceeds the first abnormality level, it becomes equal to or less than the first abnormality level before T1 time elapses. Although it is determined that there is an error, the determination result is not output to the signal output control unit 16 while the abnormality alarm is being performed.

  Subsequently, in FIG. 10, after the determination that the abnormality is the last, the sum continues for T2 hours or more and does not exceed the first abnormality level, so that it is determined to be normal. As a result, the Doppler sensor 1 is intermittently operated, and the predetermined time that is the calculation interval of the sum is the second predetermined time. Further, the reference level is updated to a new reference level D set based on the sum that does not exceed the first abnormal level and is calculated within the time T2. After that, since the sum does not exceed the first abnormal level for a while, it is determined that the sum is normal, and the reference level is updated to E.

  In FIG. 10, after the reference level is updated to E, the sum exceeds the first abnormal level. As a result, the LED blinks. In addition, the Doppler sensor 1 is in a continuous operation state, and a predetermined time that is the calculation interval of the sum is a first predetermined time. The reference level remains E without being updated.

  Then, after the sum exceeds the first abnormal level, it becomes equal to or lower than the first abnormal level before the lapse of T1 time. At this time, the maximum value of the sum exceeds the third abnormality level. Thereby, it is determined that there is an abnormality, a sound alarm is performed, and a notification to the portable device is made.

  Subsequently, after several times that the abnormality is determined, the sum exceeds the first abnormality level again. However, even if T1 time elapses after the abnormality level is exceeded, there is a state where the first abnormality level is exceeded. Continue. As a result, it is determined that the noise level has increased due to the influence of the radio wave of the mobile phone and the like, and it is determined to be normal. Then, the blinking of the LED is stopped, the Doppler sensor 1 is in an intermittent operation state, and the predetermined time that is the calculation interval of the sum is the second predetermined time. Further, the reference level is updated to a new reference level F set based on the sum calculated within the time T1.

  When the reference level is updated to F, the reference level changes greatly, and the abnormal level becomes considerably higher than before. Therefore, even if the sum is high, the first abnormal level is not exceeded. As a result, the determination that it is normal continues, and the reference level is updated in order of G and H.

  In FIG. 10, the sum of the frequency levels of all the bandwidths decreases by a certain level or more within a certain time around the timing when the reference level is updated to H. As a result, an OFF signal of the mobile phone is detected, and the memory is reset, and the number of times obtained after the reset (the number of times is less than usual (for example, 5 times) to quickly lower the reference level). The average value of the sum is set and updated to a new reference level. In FIG. 10, the reference level is updated to I. As a result, the reference level is substantially the same as the first A, and the abnormal level is also substantially the same as the first.

  Thereafter, the sum does not exceed the first abnormal level, the reference level is set and updated to J, and when the user returns to the vehicle C and operates the keyless unlocking switch, the start signal is turned off, Stop monitoring.

  Therefore, in the above embodiment, at least one of the total bandwidths for which the frequency level is obtained by FFT analysis, excluding the bandwidth including the maximum and minimum frequencies in the predetermined frequency range, is a frequency level equal to or higher than the first set level. In the case of the specific bandwidth, the second adjacent bandwidths adjacent to the specific bandwidth on the high frequency side and the low frequency side are both lower than the first set level. When the frequency is below the set level, the frequency level of the specific bandwidth is lowered, so that the bandwidth including all the disturbance frequencies can be accurately identified, and the influence of these disturbance frequencies is eliminated, and the normal It is possible to accurately determine whether there is an abnormality or not. Therefore, the movement of the moving object (person) to be monitored can be accurately grasped, and the intrusion of the moving object into the vehicle interior of the vehicle C can be accurately predicted.

  In the above-described embodiment, the Doppler sensor 1 is installed in the passenger compartment of the vehicle C and the movement of a moving object (person) located around the vehicle C is monitored. It is not limited to the vehicle and may be anywhere. For example, the Doppler sensor 1 can be installed at the entrance of a house or the like to predict the intrusion of a moving object into the house.

  Further, the present invention can be applied to any peripheral monitoring device as long as the output signal is subjected to FFT analysis using a Doppler sensor.

  INDUSTRIAL APPLICABILITY The present invention is useful for a peripheral monitoring device that uses a Doppler sensor to monitor the movement of a moving object located around the position where the Doppler sensor is installed, and in particular, prevents the moving object (person) from entering the vehicle cabin. Useful when predicting.

It is a block diagram which shows the structure of the periphery monitoring apparatus which concerns on embodiment of this invention. It is a top view of the vehicle which shows the installation position and detection range of a Doppler sensor. It is a figure which shows the change of the frequency level for every bandwidth when a person approaches and stops from the side door of a vehicle from the side of a vehicle, and moves away from it. It is a figure which shows an example of the frequency level for every bandwidth in case a disturbance frequency exists. It is a flowchart which shows the control operation of a controller. It is a flowchart which shows the specific process of a FFT analysis and determination process. It is a flowchart which shows the specific process of a disturbance frequency removal process. It is a flowchart which shows the specific process of a reference | standard level calculation process. It is a flowchart which shows the specific process of an abnormality / normality determination process. It is a time chart which shows the basic example of operation | movement of a periphery monitoring apparatus.

Explanation of symbols

C vehicle 1 Doppler sensor 11 controller 13 FFT analysis unit 14 disturbance frequency removal unit (correction means)
15 Abnormality / Normality Determination Unit 16 Signal Output Control Unit

Claims (3)

By performing FFT analysis on the output signal from the Doppler sensor, a frequency level is obtained for each bandwidth obtained by dividing a predetermined frequency range into a predetermined number of constant frequency widths, and based on the frequency level of the bandwidth, A perimeter monitoring device that monitors the movement of a moving object located around the installation position of the Doppler sensor,
At least one of the total bandwidths for which the frequency level has been obtained by the FFT analysis, excluding the bandwidth including the maximum and minimum frequencies in the predetermined frequency range, is a specific bandwidth that is a frequency level equal to or higher than the first set level. In some cases, the frequency levels of two adjacent bandwidths adjacent to the high frequency side and the low frequency side of the specific bandwidth are both equal to or lower than a second setting level lower than the first setting level. Sometimes, the periphery monitoring device is provided with a correcting means for reducing the frequency level of the specific bandwidth. The periphery monitoring device according to claim 1,
The periphery monitoring device is characterized in that the correction means is configured to set the frequency level of a specific bandwidth to an average value of the frequency levels of two adjacent bandwidths. In the periphery monitoring device according to claim 1 or 2,
The Doppler sensor is installed in the vehicle cabin,
A periphery monitoring device configured to monitor the movement of a moving object located around the vehicle and to predict the intrusion of the moving object into the vehicle interior of the vehicle.

Images