JP2003220948A - Platform fall detection device and platform fall detection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve detection performance. <P>SOLUTION: In pairs with transmitting antennas 14a to 14c, receiving antennas 15a to 15c receive respective reflected waves of transmission waves emitted by the paired transmitting antennas 14a to 14c. Demodulating means 17a to 17c demodulate the respective reflected waves by de-spreading. A logic processing means 18, if finding a coincidence between pseudo noise codes extracted by the demodulating means 17a to 17c and pseudo noise codes into which carrier waves are spread-spectrum-modulated, determines that the reflected waves received by the receiving antennas 15a to 15c paired with the transmitting antennas 14a to 14c originate from the transmission waves emitted by the paired transmitting antennas 14a to 14c, and if the reception levels of the reflected waves are within a given range, determines that an obstruction is present. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a home fall detection device and a home fall detection method for detecting an obstacle such as a fallen person from a home or a fallen object.

[0002]

2. Description of the Related Art When detecting an obstacle such as a fallen person from a home or a fallen object, it is necessary to detect an object existing within the detection range without making a blind spot by setting a long area along the home as a detection range. is there. In such a situation, a leaky transmission line such as a leaky coaxial cable or a leaky waveguide is used. In the leaky transmission line, slots are provided at predetermined intervals in the longitudinal direction of the conductor, and radio waves are leaked from the slots. Since the leaky coaxial cable and the leaky waveguide are the same in principle, the leaky coaxial cable (hereinafter referred to as LCX)
The thing using is explained. FIG. 4 is a configuration diagram of a conventional home fall detection device described in, for example, Japanese Patent Laid-Open No. 10-95338. In FIG. 4, the pulse-like signal is input from the signal generating means 1 to the transmission LCX 3 arranged along the home 2. Pulsed signal is transmitted LCX3
From each slot (not shown) provided in the longitudinal direction of
Radio waves are sequentially emitted toward the reception LCX 5 across the line 4. The signal incident from each slot (not shown) of the reception LCX 5 is received by the receiver 6. The signal received by the receiver 6 is enveloped by the low-pass filter 7 (hereinafter,
Take out the envelope). On the other hand, the envelope of the signal waveform when there is no fallen person (obstacle) is previously stored in the storage means 8 as a reference waveform. Then, each time the calculator 9 obtains the envelope of the signal waveform taken out by the low-pass filter 7, it compares it with the reference waveform of the storage means 8 to obtain a difference waveform. When an obstacle such as the fallen person 10 exists, radio waves are blocked at the existing position, so that the reception intensity at the existing position of the fallen person 10 decreases by a predetermined ratio regardless of the strength. That is, the position of the fallen person 10 appears in the difference waveform.

[0003]

Since the conventional home fall detection device is constructed as described above, since the LCXs 3 and 5 are used on both the transmitting side and the receiving side, the propagation delay time as shown in FIG. Equal radio wave propagation paths 11a to 11f
There are multiple. FIG. 5 is an explanatory diagram showing the paths of radio wave propagation in FIG. In FIG. 5, the fallen person 10 is the route 1
When the radio wave of 1d is cut off, all the radio waves of the routes 11a to 11c, 11e, and 11f other than the route 11d are route 1.
1d is received at the same level as before it was blocked by the faller 10. As described above, since the signals are combined and received as the reception signal, even if the fallen person 10 exists, only a part of the signals having the same propagation delay time is blocked,
Since the change in the received signal level by the fallen person 10 is diluted,
There is a problem that the detection sensitivity is lowered. The present invention has been made to solve the above problems,
An object of the present invention is to provide a home fall detection device capable of improving detection performance.

[0004]

A home fall object detection device according to the present invention is a home fall detection device for detecting an obstacle that has fallen on a track adjacent to a platform and within a detection range between the track and the platform. In the device, a plurality of modulation means for spread spectrum modulating a carrier wave by different pseudo noise codes to create a plurality of transmission waves, and a plurality of modulation means arranged along the home at predetermined intervals so as to share the detection range, respectively. A plurality of transmitting antennas that respectively emit the respective transmitting waves, and a plurality of receiving antennas that respectively receive the reflected waves of the transmitting waves emitted from the respective transmitting antennas paired with the respective transmitting antennas,
When a plurality of demodulation means for respectively demodulating each of the reflected waves by despreading and the pseudo noise code extracted by each of the demodulation means and the pseudo noise code obtained by spread spectrum modulating the carrier wave are received, the reception antenna receives A logical process for determining that the obstacle is present when the received level of the reflected wave is within a predetermined range, assuming that the reflected wave is the transmitted wave emitted from the pair of transmitting antennas. And means.

Further, in a home fall detection device for detecting an obstacle that has fallen on a line adjacent to a home and within a detection range between the line and the home, the carriers are spread-spectrum modulated by different pseudo noise codes. A plurality of modulation means for generating a plurality of transmission waves, a plurality of transmission antennas arranged at a predetermined interval along the home and emitting the respective transmission waves so as to share the detection range, respectively, A plurality of receiving antennas for respectively receiving the reflected waves of the transmission waves emitted from the respective transmitting antennas that form a pair with the respective transmitting antennas,
When a plurality of demodulation means for respectively demodulating each of the reflected waves by despreading and the pseudo noise code extracted by each of the demodulation means and the pseudo noise code obtained by spread spectrum modulating the carrier wave are received, the reception antenna receives It is determined that the obstacle is present when the received level of the reflected wave is within a predetermined range, assuming that the reflected wave is the transmitted wave emitted from the pair of transmitting antennas, and The present invention further comprises logic processing means for determining normal operation when the reception level of the reflected wave is equal to or lower than the reception level for judging the obstacle and the object signal is reflected in advance from the fixed equipment. Further, in the home fall detection method according to the present invention, the carrier is different in the home fall detection method for detecting an obstacle that has fallen on the track adjacent to the home and within the detection range between the track and the home. Spread spectrum modulation is performed with pseudo-noise code to create multiple transmission waves, and each of the above transmission waves is emitted from each of multiple transmission antennas arranged at predetermined intervals along the home so as to share the detection range. Then, the reception antennas paired with the transmission antennas respectively receive the reflected waves of the transmission waves emitted from the transmission antennas, demodulate the reflected waves by despreading, and extract from the reflected waves. When the generated pseudo-noise code matches the pseudo-noise code obtained by spread-spectrum modulating the carrier wave, it is received by the receiving antenna. Assuming that the obstacle is present when the reception level of the reflected wave is within a predetermined range, assuming that the reflected wave is the transmitted wave emitted from the paired transmitting antennas. Is.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. 1 is a configuration diagram of the first embodiment and FIG. 2 is a sectional view taken along line II-II of FIG. In FIGS. 1 and 2, 12 is a home, 13 is a line adjacent to the home 12, and 14a to 14c are transmission antennas arranged along the home 12 at predetermined intervals.
3 above and between the track 13 and the platform 12, for example 5 m-1
0 m is shared as the detection ranges 14a1, 14b1 and 14c1 and the transmission waves generated by the modulation means 16a to 16c described later are emitted. 15a to 15c are transmission antennas 14a to
The pair of receiving antennas 14c and 14c respectively receive the reflected waves of the transmitting waves emitted from the pair of transmitting antennas 14a to 14c. Transmitting antenna 14a and receiving antenna 15a, transmitting antenna 14b and receiving antenna 15
b, and the transmitting antenna 14c and the receiving antenna 15c are a pair, respectively. 16a to 16c are transmission antennas 1
Modulation means corresponding to 4a to 14c respectively perform spread spectrum (SS) modulation of a millimeter wave carrier with a PN (pseudo noise) code to create a transmission wave. Demodulation means 17a to 17c respectively correspond to the receiving antennas 15a to 15c, and demodulate the reflected waves received by the receiving antennas 15a to 15c by despreading. Reference numeral 18 denotes a logic processing means, in which the PN code extracted from the reflected wave received by each of the receiving antennas 15a to 15c matches the PN code used to create the transmitted wave emitted from each of the transmitting antennas 14a to 14c. At this time, it is determined that the reflected waves received by the receiving antennas 15a to 15c are emitted from the pair of partner transmitting antennas 14a to 14c, and the reception range of the reflected waves is within a predetermined level. It is determined that there is an obstacle inside. The logical processing means 18 stores the distance to the reflection point of the reflected wave and the reception level of the reflected wave as a set. Further, the logic processing means 18 is configured to detect each detection range 14
Data outside a1 to 14c1 are ignored, and trains, obstacles, fixed equipment, etc. are judged by the reception level of the reflected wave. Reference numeral 19 is a transmission means, which controls a guidance control device (not shown), a railroad crossing control device (not shown), and the like based on the determination result of the logic processing means 18.

Next, the operation will be described. FIG. 3 is an explanatory diagram showing the reception level of the reflected wave stored in the logic processing means 18. In FIG. 3, 20 is a threshold value of the reception level of the reflected wave, which is a train signal 21 and an obstacle signal 22 described later.
And the object signal 23 is determined. Reference numeral 21 denotes a train signal of a reflected wave reflected from the train, which has a threshold value of 20 or more. 22 is an obstacle (not shown) in each of the detection ranges 14a1 to 14c1
An obstacle signal indicating the reception level of the reflected wave reflected from the
Reference numeral 23 is an object signal indicating the reception level of the reflected wave reflected from the fixed equipment such as the line 13 installed in each of the detection ranges 14a1 to 14c1. An obstacle detection level range 24 is determined as an obstacle when the reception level is within this range. 1 to 3, the modulation means 16a to 16c
The detection range of the transmission wave created in
a1 to 14c1 toward the transmitting antennas 14a to 14c
Fire from. When there is no obstacle in the detection range 14a1 to 14c1, the transmitting antennas 14a to 14c and the pair of receiving antennas 15a to 15c of the partner receive the reflected waves reflected from the existing equipment. The received reflected waves are demodulated by despreading by the demodulation means 17a to 17c corresponding to the receiving antennas 15a to 15c, respectively.
Then, the logic processing means 18 is provided for each of the demodulation means 17a-17c
When the PN (pseudo noise) code extracted in step 1 and the PN (pseudo noise) code obtained by spread-spectrum-modulating the carrier wave match, the reflected waves received by the receiving antennas 15a to 15c are paired with the transmitting antennas 14a to 14a, respectively. It is determined that the image is emitted from 14c. Furthermore, the logic processing means 18 correlates the reception level of the reflected wave with the reception level with respect to the stored distance to the reflection point. Then, the object signal 2 whose reception level is less than or equal to the obstacle detection level range 24
When the reflected wave of the reception level of 3 is received, the soundness of the device can be confirmed by the self-check function.

On the other hand, for example, when an obstacle exists in the detection range 14a1, the transmission wave emitted from the transmission antenna 14a is reflected by the obstacle, and the reception antenna 15a receives the reflected wave. The received reflected wave is demodulation means 17a
Is demodulated by despreading. Then, the logic processing means 18
When the PN code extracted by the demodulating means 17 matches the PN code obtained by spread spectrum modulating the carrier, the reflected wave received by the transmitting antenna 14a and the pair of receiving antennas 15a is transmitted from the paired transmitting antennas 14a. Judged as fired. Further, the logic processing means 18 is shown in FIG.
Correlation with the reception level of the reflected wave shown in FIG.
When it is, it is determined that an obstacle exists within the detection range 14a1. The detection range 14b1 or the detection range 14c
When there is an obstacle in 1, the logic processing means 18 determines that there is an obstacle in each of the detection ranges 14b1 and 14c1 as in the case where the obstacle exists in the detection range 14a1. As described above, when the pseudo noise code extracted by the demodulation means 17a to 17c and the pseudo noise code obtained by spread spectrum modulating the carrier wave match, the transmitting antennas 14a to 1
4c and the pair of receiving antennas 15a to 15c, the reflected waves are determined to be the transmitted waves emitted from the pair of transmitting antennas 14a to 14c, and the reception level of the reflected waves is within a predetermined range. Sometimes, the detection range 14a1-1
By determining that there is an obstacle in 4c1, it is possible to accurately detect the obstacle within the detection range without being affected by external noise or a change in the weather.

[0009]

According to the present invention, when the pseudo-noise code extracted by the demodulating means and the pseudo-noise code obtained by spread-spectrum modulating the carrier match, the reflected wave received by the transmitting antenna and the pair of receiving antennas is generated. By determining that the transmitted wave is emitted from a pair of transmitting antennas, and when the reception level of the reflected wave is within a predetermined range, it is determined that an obstacle is present in the detection range, and external noise or Obstacles within the detection range can be accurately detected without being affected by changes in the weather. Further, when the pseudo noise code extracted by the demodulation means and the pseudo noise code obtained by spread-spectrum modulating the carrier wave match, the reflected wave received by the transmitting antenna and the pair of receiving antennas is transmitted from the pair of transmitting antennas. It is determined that it is a wave, and it is determined that there is an obstacle when the reception level of the reflected wave is within a predetermined range, and the reception level of the reflected wave is stored in advance below the reception level for determining the obstacle. By determining that the normal operation when the object signal due to the reflection from the fixed equipment, it is possible to accurately detect the obstacle within the detection range without being affected by external noise or weather changes, With the self-check function, it is possible to constantly check the soundness of the device.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is an explanatory diagram showing a reception level of a reflected wave stored in the logic processing means of FIG.

FIG. 4 is a configuration diagram of a conventional home fall detection device.

5 is an explanatory view showing a radio wave propagation path in FIG. 4. FIG.

[Explanation of symbols]

12 homes, 13 lines, 14a to 14c transmitting antennas, 15a to 15c receiving antennas, 16a to 16c
Modulation means, 17a to 17c Demodulation means, 18 Logic processing means.

Claims (3)

[Claims] 1. A home fall detection device for detecting an obstacle that has fallen on a line adjacent to a home and within a detection range between the line and the home, wherein a carrier is spread spectrum modulated by different pseudo noise codes. A plurality of modulation means for generating a plurality of transmission waves, a plurality of transmission antennas arranged at a predetermined interval along the home and emitting the respective transmission waves so as to share the detection range, respectively, A plurality of receiving antennas for respectively receiving the reflected waves of the transmission waves emitted from the respective transmitting antennas forming a pair with the respective transmitting antennas, and a plurality of demodulating means for respectively demodulating the respective reflected waves by despreading, When the pseudo noise code extracted by each of the demodulation means and the pseudo noise code obtained by spread spectrum modulating the carrier are matched, the reception Assuming that the reflected wave received by the reception antenna is that of the transmission wave emitted from the pair of transmission antennas and that the obstacle exists when the reception level of the reflection wave is within a predetermined range. A home fall detection device comprising a logical processing means for making a decision. 2. A home fall detection device for detecting an obstacle that has fallen on a line adjacent to a home and within a detection range between the line and the home, wherein a carrier is spread spectrum modulated by different pseudo noise codes. A plurality of modulation means for generating a plurality of transmission waves, a plurality of transmission antennas arranged at a predetermined interval along the home and emitting the respective transmission waves so as to share the detection range, respectively, A plurality of receiving antennas for respectively receiving the reflected waves of the transmission waves emitted from the respective transmitting antennas forming a pair with the respective transmitting antennas, and a plurality of demodulating means for respectively demodulating the respective reflected waves by despreading, When the pseudo noise code extracted by each of the demodulation means and the pseudo noise code obtained by spread spectrum modulating the carrier are matched, the reception Assuming that the reflected wave received by the reception antenna is that of the transmission wave emitted from the pair of transmission antennas and that the obstacle exists when the reception level of the reflection wave is within a predetermined range. A home fall equipped with a logic processing means for determining that the reception signal level of the reflected wave is equal to or lower than the reception level for determining the obstacle and normal operation is determined when the object signal is caused by reflection from a fixed facility. Detection device. 3. A home fall detection method for detecting an obstacle that falls on a line adjacent to a home and within a detection range between the line and the home, wherein a carrier is spread spectrum modulated by different pseudo noise codes. To generate a plurality of transmission waves, emit the respective transmission waves from the plurality of transmission antennas arranged at a predetermined interval along the home so as to share the detection range, respectively, and pair with the transmission antennas. Each of the reception waves reflected by the transmission wave emitted from each of the transmission antennas is received by the reception antenna, and each of the reflection waves is demodulated by despreading, and the pseudo noise code and the carrier wave extracted from the reflection wave are received. When the pseudo-noise code obtained by spread-spectrum-modulating is matched with the transmission antenna, the reflected wave received by the receiving antenna forms a pair. A home fall detection method, wherein it is determined that the obstacle is present when the reception level of the reflected wave is within a predetermined range, assuming that the obstacle is the transmitted wave emitted from the antenna.