JP2007207001A - Vehicle monitoring apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide technology for monitoring a relatively broad area using a miniature and low power consumption constitution. <P>SOLUTION: An oscillating device 1 forms a predetermined electromagnetic field in the monitoring area of a vehicle, a detecting device 2 detects the electromagnetic fields generated in the monitoring field, and the existence of a body approaching or coming into contact (dielectric material, such as human being and substance) is determined, based on the detected result. The detection device 2, for example, considers a body approaching or coming into contact, when the detected electromagnetic fields change from the steady state. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technique for detecting a person or an object approaching or contacting a vehicle.

  Various types of monitoring devices are provided in the vehicle according to the purpose. For example, in order to realize so-called passive entry (a mechanism that automatically unlocks the door when a person holding an electronic key approaches), a monitoring device that detects the approach of the hand to the door handle, For example, a monitoring device that detects a suspicious person approaching the vehicle.

  In such a monitoring apparatus, various sensors are used as means for detecting contact or approach of a person or an object. An example is a radio wave sensor or an electrostatic sensor. For example, in the case of a radio wave sensor, radio waves are radiated from a transmitter installed in a monitoring area in the vehicle, and radio waves reflected by a detection target are received to detect contact or approach.

As a known sensor, an electric field sensor using an electro-optic crystal is also known. This type of electric field sensor is expected to be used in a device that performs non-contact inspection of an IC card and a mechanism that transmits and receives information between wearable computers (see Patent Documents 1 to 4).
JP 2000-57272 A JP 2001-352298 A JP 2001-352299 A Japanese Patent Application Laid-Open No. 2004-274452

  In a conventional monitoring apparatus using a radio wave sensor, an electrostatic sensor, or the like, the irradiation range of the sensor signal is a monitoring area. Therefore, in order to monitor a wide range (for example, the entire vehicle or the entire door), it is necessary to provide a plurality of sensors or increase the output of the sensors. However, if it does so, there exists a problem that the freedom degree of the installation in a vehicle falls by enlargement of an apparatus, or causes disadvantages, such as an increase in cost and an increase in power consumption.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technique capable of monitoring a relatively wide area with a small size and low power consumption configuration.

  In order to achieve the above object, the present invention adopts the following configuration.

  A vehicle monitoring apparatus according to the present invention is based on an electric field forming unit that forms a predetermined electric field in a monitoring region of a vehicle, an electric field detection unit that detects an electric field generated in the monitoring region, and a detection result of the electric field detection unit. And a determination unit that determines whether or not there is an object that approaches or contacts the monitoring area.

  The electric field forming unit forms a predetermined electric field by applying a predetermined voltage to the monitoring region. At this time, the electric field may be formed so that the electric field distribution in the monitoring region takes a certain static state, or the electric field may be formed so that the electric field distribution in the monitoring region causes a certain period of fluctuation. .

What is necessary is just to set a monitoring area | region suitably according to the use and the objective of a vehicle monitoring apparatus. For example, by forming an electric field on the entire vehicle, the entire vehicle can be set as a monitoring region. It is also possible to form an electric field on a part of the vehicle (door, door handle, window, window frame, weather strip, etc.) and use only that part as a monitoring area.

  When a dielectric such as a person or an object enters the electric field generated in the monitoring area, the electric field distribution changes (disturbs). This minute change in the electric field distribution can be detected by an electric field detector provided in the electric field. Therefore, by detecting the electric field in the monitoring region with the electric field detection unit and analyzing the detection result with the determination unit, it is possible to accurately determine whether or not there is something (a person or an object) approaching or contacting the monitoring region.

  Specifically, it is preferable that the determination unit considers that there is something that approaches or contacts the monitoring region when the electric field detected by the electric field detection unit changes from a steady state. The steady state is an electric field distribution formed by the electric field forming unit.

  The present invention described above can also be grasped as a vehicle monitoring method. That is, the vehicle monitoring method according to the present invention forms a predetermined electric field in the monitoring area of the vehicle, detects the electric field generated in the monitoring area, and approaches or contacts the monitoring area based on the detection result. It is to determine whether or not something exists.

  According to the present invention, since a predetermined electric field is formed in the monitoring area and a change in the electric field is monitored, an object approaching or contacting the monitoring area can be detected. A wide area can be monitored with a low power consumption configuration.

  Exemplary embodiments of the present invention will be described in detail below with reference to the drawings.

  FIG. 1 shows a configuration of a vehicle monitoring apparatus according to an embodiment of the present invention. This vehicle monitoring device is an example in which the present invention is applied to a crime prevention device that detects a suspicious person approaching a vehicle.

  The vehicle monitoring device generally includes an oscillation device 1, a detection device 2, and a processing device 3. The oscillation device 1, the detection device 2, and the processing device 3 may be installed as different units in different positions in the vehicle as shown in FIG. 1, or may be a single unit.

  The oscillation device 1 is an electric field forming unit that forms a predetermined electric field on the entire vehicle that is a monitoring region by applying a predetermined voltage to the vehicle body. By using a constant DC voltage as the applied voltage, the electric field distribution may be in a certain static state, or by using an AC voltage that varies in a certain period, the electric field distribution varies in a certain period. May be generated. The direction of the electric field may be any of the horizontal direction, vertical direction, and diagonal direction of the vehicle body.

  As shown in FIG. 2, the detection device 2 includes an electric field sensor 4 as an electric field detection unit, and a determination unit 5 that analyzes an output (detection result) of the electric field sensor 4. The electric field sensor 4 detects (monitors) the electric field generated in the vehicle body at predetermined time intervals and outputs the detection result (electric signal) to the determination unit. The determination unit 5 determines whether or not the electric field distribution in the vehicle body has changed by analyzing the signal.

In the present embodiment, as the electric field sensor 4, a so-called photonic electric field sensor that measures an electric field using the electro-optic effect of an electro-optic crystal is used. The electric field sensor 4 mainly includes an electro-optic crystal 40, a laser light source (laser diode or the like) 41 that irradiates the electro-optic crystal 40 with laser light, and a polarization state of the laser light that has passed through the electro-optic crystal 40. An analyzer 42 that converts light intensity and a photoelectric conversion element (such as a photodiode) 43 that detects light that has passed through the analyzer 42 are provided.

  When the electric field generated in the monitoring region (vehicle body) is coupled to the electro-optic crystal 40, the birefringence of the crystal 40 changes according to the electric field strength (this is referred to as “electro-optic effect”), and the polarization state of the laser light Changes. This change in the polarization state is converted into a voltage change of an electric signal by the analyzer 42 and the photoelectric conversion element 43. The output of the photoelectric conversion element 43 is amplified and shaped as necessary, and then input to the determination unit 5.

  As described above, a predetermined electric field distribution is formed in the vehicle body that is the monitoring region by the action of the oscillation device 1 (this state is referred to as “steady state”). In this steady state, the output signal of the electric field sensor 4 input to the determination unit 5 also takes a steady waveform. On the other hand, when a dielectric such as a person or an object enters somewhere in the electric field generated in the monitoring area, some change (disturbance) occurs in the electric field distribution (this state is called “unsteady state”), and the electric field sensor A change also appears in the output signal 4. The determination unit 5 determines, for example, a steady state (no change) or an unsteady state (change) by taking out a differential signal of the sensor output. When it is in an unsteady state, it is considered that there is something that approaches or contacts the monitoring area, and a detection signal is output to the processing device 3. In the steady state, the output is 0 (none).

  In addition, the determination process in the determination part 5 is not restricted to this example. Any method may be used as long as it can detect that the sensor output has changed from the steady state, and analog signal processing or digital signal processing may be used. The format of the detection signal from the determination unit 5 is not limited to the above example and can be set as appropriate.

  When the detection signal is input from the determination unit 5, the processing device 3 performs a predetermined crime prevention process. Examples of the crime prevention process include output of alarms and warnings, irradiation of threatening light, and reporting to the handset terminal and the management center.

  According to the configuration of the present embodiment described above, it is possible to detect an object approaching or contacting the monitoring region only by forming a predetermined electric field in the monitoring region and monitoring the change in the electric field. According to this configuration, it is easy to expand the monitoring area over a wide range such as the entire vehicle as compared with a conventional radio wave sensor or the like. Therefore, it is possible to monitor a relatively wide area with a configuration that is smaller and consumes less power than in the past. And vehicle damage such as theft or mischief can be suppressed by executing a predetermined crime prevention process according to the detection signal.

<Modification>
The above embodiment is merely an example of the present invention. The scope of the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the technical idea. Hereinafter, a suitable modification is illustrated.

  (1) The direction of the electric field formed in the monitoring area may be switched at a predetermined cycle. For example, the horizontal and vertical electric fields are alternately switched to detect and evaluate both the change in the horizontal electric field and the change in the vertical electric field. Thereby, detection accuracy can be improved.

  (2) The monitoring area is divided into a plurality of small areas, and the formation and detection processing of the electric field is sequentially performed on each small area (by time division), thereby identifying the small area where the change in the electric field distribution is most remarkable. Is also preferable. Thereby, it is possible to narrow down in which area the suspicious person or the like is in the monitoring area.

In this method, the monitoring region is divided into M rows and detection processing is performed in order, and the detection processing is performed by dividing the monitoring region into N columns (M and N are integers greater than 1), and the change in the electric field distribution is remarkable. It is also preferable to specify a correct row / column. With this method, the position of a suspicious person or the like can be specified with (M × N) resolution by (M + N) detection processes.

  (3) In the above embodiment, the entire vehicle is the monitoring area, but only a part of the vehicle may be the monitoring area. Moreover, in the said embodiment, although the example of the crime prevention apparatus which detects a suspicious person and a suspicious object was given, this invention is applicable to other various vehicle monitoring apparatuses (sensor system).

  For example, an electric field may be formed on a door window, a window frame, a weather strip, or the like to detect an object close to the door window. By prohibiting the operation of the power window based on the detection result, it is possible to prevent an accident of pinching a finger or a hand.

  Alternatively, an electric field may be formed at the entrance of the slide door. By prohibiting the operation of the slide door based on the detection result, it is possible to prevent an accident of pinching a finger or a hand by the slide door.

  Alternatively, an electric field may be formed at and near the door handle to detect approach or contact of the hand to the door handle. This detection result can be used to control passive entries.

It is a figure which shows the structure of a vehicle monitoring apparatus. It is a figure which shows the structure of a detection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Oscillator 2 Detection apparatus 3 Processing apparatus 4 Electric field sensor 5 Judgment part 40 Electro-optic crystal 41 Laser light source 42 Analyzer 43 Photoelectric conversion element

Claims (3)

An electric field forming unit for forming a predetermined electric field in a monitoring region of the vehicle;
An electric field detector for detecting an electric field generated in the monitoring region;
Based on the detection result of the electric field detection unit, a determination unit that determines whether there is something that approaches or contacts the monitoring region;
A vehicle monitoring device comprising:   2. The vehicle monitoring according to claim 1, wherein when the electric field detected by the electric field detection unit changes from a steady state, the determination unit considers that there is something that approaches or contacts the monitoring region. apparatus. Form a predetermined electric field in the monitoring area of the vehicle,
Detecting an electric field generated in the monitoring area;
A vehicle monitoring method characterized by determining whether there is an object approaching or contacting the monitoring area based on the detection result.

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