JP2014032625A - In-cabin situation observation device and in-cabin accident prevention device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly and accurately observe a passenger's movement in a passenger compartment with good responsiveness while having a relatively simple and low-cost configuration, so that a passenger can quickly detect without overlooking a dangerous movement of a passenger. Provided is a vehicle interior situation observation device that can realize a safe operation by urging attention and avoiding dangerous vehicle start operations that do not take passenger movements into consideration.
The present invention relates to a vehicle interior condition observation device 100 for observing the movement of a measurement object in a vehicle interior, comprising a two-output CW Doppler sensor 110, and detecting the moving speed of the measurement object using the Doppler effect. In addition, the movement direction of the measurement target is distinguished from the phase difference between the two outputs, and the movement of the measurement target in the passenger compartment of the vehicle 200 can be observed.
[Selection] Figure 1

Description

  The present invention relates to a vehicle interior situation observation device (system) for observing passenger movement in a vehicle interior in a one-man bus or the like, and a vehicle interior accident prevention device (system) using the device.

  Up to now, as an example of this type of vehicle interior condition observation device (system), for example, in order to make it easier to check the situation of passengers in a vehicle interior such as a one-man bus, a reflection mirror has been installed in the vehicle interior or visible. In difficult places, a monitor device using a CCD camera etc. is installed in the passenger compartment, and the driver in the driver's seat checks the movement of passengers etc. via the reflection mirror and monitor device, and the passengers before the vehicle stops Attention has been paid to getting up and moving around the passage, and avoiding the vehicle starting operation before the passenger is seated, etc., so that it can be operated safely.

  However, in order for the driver to observe the reflecting mirror and monitor device, mistakes and oversights are assumed, and appropriate skills are required.There is room for further improvement in order to further improve safety. It is thought that it is left behind.

  For example, various moving body detection techniques for detecting the movement of a moving body by performing image processing on image information acquired from a CCD camera have been proposed (see, for example, Patent Document 1).

JP 2011-34458 A

  However, in order to be installed in a vehicle as a vehicle interior situation observation device (system), it is necessary to implement a program with a large processing load. Since it is required to increase the calculation speed of the CPU and the read / write speed of the memory and to increase the capacity of the storage area, there is a situation that the cost is increased and the cost effectiveness is not good.

  The present invention has been made in view of such a situation, and is capable of accurately observing movements of passengers in a passenger compartment such as a one-man bus with high responsiveness while having a relatively simple and low-cost configuration. Car interior situation observation that can realize safe operation by avoiding dangerous vehicle start operations etc. that do not consider passenger movements quickly, without overlooking passengers' dangerous movements An object of the present invention is to provide a device (system) and thus a vehicle interior accident prevention device (system).

For this reason, the vehicle interior condition observation device according to the present invention is
A vehicle interior situation observation device for observing the movement of a measurement target in a vehicle interior,
A CW Doppler sensor is provided, and the movement speed of the measurement object is detected by using the Doppler effect so that the movement of the measurement object in the passenger compartment can be observed.

Moreover, the vehicle interior condition observation device according to the present invention is
A vehicle interior situation observation device for observing the movement of a measurement target in a vehicle interior,
Equipped with a two-output CW Doppler sensor, detects the moving speed of the measurement object using the Doppler effect and distinguishes the direction of movement of the measurement object from the phase difference between the two outputs to observe the movement of the measurement object in the passenger compartment It is configured to be possible.

  The present invention is characterized by observing the movement of the measurement object while removing the vibration caused by the vehicle running by integrating the moving speed and phase difference of the measurement object acquired by the two-output CW Doppler sensor. be able to.

  In the present invention, the information acquired by the two-output CW Doppler sensor is integrated for a certain period of time with a band other than the value that can be taken by the moving speed of the measuring object, and the movement of the measuring object is determined based on the integrated value. A threshold value can be set.

  Further, the vehicle interior accident prevention apparatus according to the present invention includes the above-described vehicle interior situation observation apparatus according to the present invention, and the observation result of the movement of the measurement object by the vehicle interior situation observation apparatus causes a vehicle interior accident. When there is a fear, the vehicle driver or the passenger is notified.

  ADVANTAGE OF THE INVENTION According to this invention, although it is a comparatively simple and low-cost structure, a passenger | crew's movement in vehicle interiors, such as a one-man bus, can be observed accurately with sufficient responsiveness, and a passenger's dangerous movement is overlooked. A vehicle interior condition observation system (system) that can contribute to the realization of safe operation by avoiding dangerous vehicle start operations that do not take passenger movements into account Can provide a vehicle interior accident prevention device (system).

1 is a system diagram schematically illustrating a vehicle interior situation observation device (system) and a vehicle interior accident prevention device (system) according to an embodiment of the present invention. It is a block diagram which shows an example of the internal circuit of 2 output CW Doppler sensor (2 frequency CW Doppler radar) based on embodiment same as the above. It is a time chart which shows an example of the output waveform of the 2 output CW Doppler sensor (2 frequency CW Doppler radar) which concerns on embodiment same as the above. In the vehicle interior situation observation device (system) and vehicle interior accident prevention device (system) according to the above-described embodiment, the motion determination logic of the mobile body (distinguishes from vibration caused by shaking while the vehicle is running, It is a block diagram explaining an example of the case of detecting the motion of (object). It is a time chart which shows an example of the waveform data in the vehicle interior condition observation apparatus (system) which concerns on embodiment same as the above, (A) is a threshold value, (B) is the characteristic of the rising waveform from a seat (In the figure, the arrow is a waveform. (C) is a diagram showing the waveform characteristics of the first step of walking from the seat (the arrow in the figure is the starting frequency of the characteristic change of the waveform). An example of a moving body movement determination logic (when a movement determination threshold value is variably set according to a vehicle running state) in the vehicle interior condition observation apparatus (system) and the vehicle interior accident prevention apparatus (system) according to the embodiment described above FIG.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the accompanying drawings. The present invention is not limited to the embodiments described below.

  A vehicle interior accident prevention apparatus (system) 1 according to an embodiment of the present invention includes a vehicle interior situation observation (detection) apparatus (system) 100 provided in a vehicle interior of a vehicle 200 as shown in FIG. The vehicle interior is configured to execute various arithmetic processes on information acquired from a sensor (radar) configured to detect movement of passengers and the like based on a motion determination logic in an electronic control unit (ECU) 300, etc. By observing (detecting) the situation and depending on the situation such as the degree of danger, the result is notified to the driver via the support device 400 provided near the driver's seat, or to the passengers, etc. An accident such as a passenger falling in the passenger compartment can be prevented.

  A vehicle interior condition observing apparatus (system) 100 used in the present embodiment includes a relatively low-cost two-output CW Doppler sensor (Continuous Wave Doppler Sensor) 110. The 2-output CW Doppler sensor is also referred to as a 2-output CW Doppler radar.

  The CW Doppler sensor (Continuous Wave Doppler Sensor) is a sensor that can detect the relative velocity with an object using the Doppler effect, and the two-output CW Doppler sensor 110 has two outputs (for example, 24.15 GHz). And the direction of the movement of the object (approaching or separating (leaving, moving away)) can be distinguished from the phase difference between the two and the 24.55 GHz output. For example, Japanese Patent Application Laid-Open No. 2005-201774 can be referred to for the distance measuring method of the moving body by the CW Doppler sensor.

The internal circuit of the two-output CW Doppler sensor 110 is an example, but has a configuration as shown in FIG.
Here, FIG. 3 shows an example of output waveforms of IF1 and IF2.
Relationship with measurement object (moving body) movement:
Movement speed: proportional to IF1 and IF2 frequencies.
Movement direction: Can be distinguished based on the phase difference between IF1 and IF2.
When the moving body is approaching the sensor: IF1 phase is earlier than IF2 When the moving body is moving away from the sensor: IF2 phase is earlier than IF1

  In this embodiment, as shown in FIG. 1, such a two-output CW Doppler sensor 110 is configured to be installed in the vicinity of the front of the vehicle interior of a vehicle 200 such as a one-man bus.

  Information acquired by the two-output CW Doppler sensor 110 is input to an electronic control unit (ECU) 300 including a CPU, ROM, RAM, various I / Fs, and the like, and various program processes are performed here. It has become so.

  As shown in FIG. 1, for example, when the passengers A and B move, for example, when they stand up from their seats before the vehicle stops or move through the passage 210 while traveling, the two-output CW Doppler sensor 110 is turned on. The vehicle interior situation observation apparatus (system) 100 provided is executed by an electronic control unit (ECU) 300 that executes various arithmetic processes based on movement determination logic and the like, detects this, and detects the vehicle interior accident prevention apparatus (system). 1) is configured so that it can be notified to the driver via a support device 400 provided in the vicinity of the driver's seat by turning on a lamp or sounding an alarm or the like.

  In such a case, the driver can realize safe operation by not applying the brake as strongly as possible so that the passenger does not fall.

  Further, in the vehicle interior situation observation device (system) 100 and further in the vehicle interior accident prevention device (system) 1, for example, depending on the degree of danger (for example, severity) of movement of the passengers A and B, the degree of danger is high (severe ) When a motion is detected, for example, an automatic broadcasting device is automatically activated via the support device 400, and a warning is given to the passenger not to walk dangerously by voice or the like. It is also possible to configure so as to.

  Further, for example, when the passenger is still moving in the passenger compartment after getting on at a bus stop or the like, the vehicle interior situation observation device (system) 100 including the two-output CW Doppler sensor 110 is further prevented. The device (system) 1 detects this by an electronic control unit (ECU) 300, and lights a lamp or a warning sound to the driver via a support device 400 provided near the driver's seat. It can be set as the structure which alert | reports by sounding.

  As a result, the driver can realize a safe operation such that the passenger does not fall down, such as not starting the vehicle until the passenger is seated or grabbed by a handrail or hanging leather, and stopped. .

  As described above, according to the vehicle interior condition observation apparatus (system) 100 according to the present embodiment, the movement of passengers in the vehicle interior of a one-man bus or the like can be accurately performed with high responsiveness, while having a relatively simple and low-cost configuration. Therefore, without overlooking the dangerous movements of passengers, they can quickly detect and call attention, and avoid dangerous vehicle start operations that do not take passenger movements into account, thereby ensuring safe operation. It is possible to provide a vehicle interior situation observation device (system) that can contribute to the realization of the vehicle interior accident prevention device (system).

  In the above-described embodiment, the two-output CW Doppler sensor 110 is provided, the moving speed and the moving direction of the measurement target (moving body) are detected, and the movement of the measurement target is observed. The invention is not limited to this. For example, a one-output CW Doppler sensor (for example, only outputs an output wave IF1 in the 24 GHz band) is provided, and a measurement object (moving) is utilized by using the Doppler effect by the one-output CW Doppler sensor. It is also possible to detect the movement speed of the body and observe the movement of the measurement object in the passenger compartment.

  Here, when the 2-output CW Doppler sensor 110 is mounted on a vehicle such as a bus as in the present embodiment described above, vibration due to shaking while the vehicle is traveling and movement of a moving body (measurement target) such as a pedestrian. Can be detected (separated) and the movement of a moving body (measurement target) such as a pedestrian can be detected, the detection accuracy of the movement of the mobile body (measurement target) such as a pedestrian can be improved.

  For this reason, in this embodiment, the sign of the direction of movement of the moving object (information on approach or separation (separation)) is obtained from the information on the phase difference acquired by the two-output CW Doppler sensor 110, and the relative speed is obtained. Integration is performed so as to remove regular vibrations caused by running of the vehicle.

As shown in FIG. 4 as an example of the movement determination logic, in this embodiment,
In a block (denoted as B) 301, FFT processing (fast Fourier transform processing) is performed on IF1 and IF2 acquired by the two-output CW Doppler sensor 110.

  In B302, a threshold value is obtained by performing clutter processing on IF1 and IF2 that have passed B301 (see FIG. 5A).

  In B303, the peak frequency is detected. That is, as understood from FIGS. 5B and 5C, the type of movement of the moving object can be distinguished according to the peak frequency.

In B304, the relative speed of LF1 and LF2 is detected.
That is, the moving speed of the moving body with respect to the two-output CW Doppler sensor 110 and the vehicle 200 is detected.

In B305, the phase difference between LF1 and LF2 is detected.
That is, the moving direction of the moving body with respect to the two-output CW Doppler sensor 110 and the vehicle 200 is detected.

  Subsequently, in B306, an integration process (integration process) is performed on the outputs from B304 and B305. By executing the integration process (integration process), the movement of an object or a person that is shaking on the spot is canceled (cancelled) because the movement directions are alternately opposed, and even if the integration process is performed, Its value does not tend to increase or decrease.

  Therefore, when a moving body (measuring object) such as a passenger approaches or leaves the 2-output CW Doppler sensor 110, something vibrates on the spot. When a moving body (measurement target) such as a passenger is approaching or leaving the 2-output CW Doppler sensor 110 with high accuracy, the case is separated from the case where it is present (retreats far). The case can be detected.

  Subsequently, in B307, the moving and static determination of a moving body (measurement target) such as a passenger is performed in comparison with the threshold set in B302 (or a threshold obtained in advance through experiments or the like).

  In addition, according to this determination result (the magnitude of deviation from the threshold value, etc.), as described above, the support device 400 provided near the driver's seat is used to alert the passengers via an automatic broadcast device or the like. In addition, the driver can be notified by turning on a lamp or sounding an alarm sound, etc., so that safe operation can be realized so that the passenger does not fall over.

  By the way, when the threshold value used in B307 described above is a constant value, the threshold value becomes incompatible depending on vehicle running conditions (vehicle running conditions such as road surface conditions and vehicle speed changes) and vehicle interior conditions such as the degree of congestion in the vehicle interior, It is also assumed that the determination accuracy is lowered and an erroneous determination is caused.

  For this reason, in the present embodiment, a band other than a value that can be taken by the moving speed (passenger walking speed) of the moving object to be measured is integrated for a certain time (for example, 1 minute). This certain time can be changed as appropriate.

  In addition, it can be set as the structure which updates an integral value whenever fixed time passes. As a result, the acquired integral value can be changed in accordance with changes in vehicle driving conditions (vehicle driving conditions such as road surface conditions and vehicle speed changes).

Specifically, as shown in FIG.
At B308, noise components are removed from IF1 and IF2 that have been subjected to FFT processing through B301 and B302, and thereafter, integration processing is executed at B309.
The frequency characteristic of the band elimination filter of B308 is set so as to attenuate the Doppler frequency range corresponding to the human walking speed.
Assumed walking speed: For example, 0.8 to 1.3 m / s
Corresponding Doppler frequency: 130-210 Hz (for 24 GHz sensor)

  The integral value obtained in B309 is the noise generated by factors other than the movement of the moving body (passenger's walking) that is the measurement target (that is, the movement other than the specific change such as the walking of the passenger) A threshold value for determination is set based on this value as a reference based on this value.

  That is, in B309, a predetermined constant (initial threshold value) is multiplied by the integral value obtained in B308, so that the actual vehicle running conditions (vehicle running conditions such as road surface conditions and vehicle speed changes) are obtained. ) Is set as a threshold value used in B307, and a new threshold value that can eliminate periodic shaking such as passengers or objects in the passenger compartment is generated.

  Therefore, according to the present embodiment, band information other than the values that can be taken by the moving speed (passenger walking speed) of the moving object to be measured is considered as noise, and a value in consideration of this noise is used as a threshold value. As a result, it is possible to determine the movement of the moving body (measurement target) such as a passenger with higher accuracy.

  As described above, according to the present embodiment, it is possible to accurately observe the movements of passengers in a passenger compartment such as a one-man bus with a relatively simple and low-cost configuration. The passenger compartment that can contribute to the realization of safe operation by avoiding dangerous vehicle start operations that do not take passenger movements into account, and quickly detect and alert without overlooking the passengers' dangerous movements A situation observing device (system), that is, a vehicle interior accident preventing device (system) can be provided.

  The present invention is not limited to the embodiments of the invention described above, and various modifications can be made without departing from the gist of the present invention.

1 Car accident prevention device (system)
100 Car interior condition observation system (system)
110 2 output CW Doppler sensor (2 output CW Doppler radar)
200 vehicles (such as buses)
300 Electronic control unit (ECU)
400 Support devices (warning lamps, automatic broadcast devices, etc.)

Claims (5)

A vehicle interior situation observation device for observing the movement of a measurement target in a vehicle interior,
A vehicle interior situation observing apparatus comprising a CW Doppler sensor and configured to be able to observe a movement of a measurement object in a vehicle interior by detecting a moving speed of the measurement object using a Doppler effect. A vehicle interior situation observation device for observing the movement of a measurement target in a vehicle interior,
Equipped with a two-output CW Doppler sensor, detects the moving speed of the measurement object using the Doppler effect and distinguishes the direction of movement of the measurement object from the phase difference between the two outputs to observe the movement of the measurement object in the passenger compartment A vehicle interior condition observing device characterized in that it can be configured.   3. The movement of the measurement target is observed while removing the vibration caused by the vehicle running by integrating the moving speed and phase difference of the measurement target acquired by the two-output CW Doppler sensor. The vehicle interior condition observation device described.   For information acquired by the two-output CW Doppler sensor, a band other than the value that can be taken by the moving speed of the measurement target is integrated for a certain period of time, and a threshold value for determining the movement of the measurement target is set based on the integration value. The vehicle interior condition observation device according to claim 2 or claim 3, wherein   When the vehicle interior condition observation device according to any one of claims 1 to 4 is included, and the observation result of the movement of the measurement object by the vehicle interior condition observation device may cause an accident in the vehicle interior. In addition, the vehicle interior accident prevention apparatus is characterized by notifying at least one of a vehicle driver or a passenger.