JPH06223298A - Parking state detection system - Google Patents

Abstract

PURPOSE:To detect even parking states in respective parking areas, to improve reliability, to improve maintainability and to prevent the increase of the burden of costs by reducing the wiring of communication cables. CONSTITUTION:Respective photosensors 25 and slave MODEMs 24 are connected through a communication line 23a for group communication use and a power line 23 so as to manage the plural photosensors 25 provided at every parking area 11 by the several slave MODEMs 24 and the respective slave MODEMs 24 and a master MODEM 21a are connected through the power line 23. Then, by power line communication through the power line 23, a sensor operating command part 21b transmits sensor operating commands to the respective slave MODEMs 24 and a parking information gathering part 21c gathers the parking states detected by the respective photosensors 25 and displays the results at display parts 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a common or common electric power line to detect the parking state of each parking area in a parking lot and obtain the parking state of all parking areas. Regarding

[0002]

2. Description of the Related Art Recently, a parking state detection system for detecting whether a vehicle is full or empty in a parking lot has been employed.

One of such systems is to count the number of vehicles by a time register, a card system, a photoelectric sensor, etc. at the time of entering and exiting a parking lot, and obtain the difference between the number of entering vehicles and the number of leaving vehicles. There is a system that obtains the difference between the number of parked vehicles and the maximum number of parked vehicles, and displays the parking state whether the vehicle is "full" or "empty".

There is also a parking state detection system for detecting the parking state for each parking area, one example of which is shown in FIG.

In the parking state detection system shown in FIG. 5, a photoelectric sensor 12 is provided above each parking area 11 where one vehicle 14 is parked in the parking lot 1, and each photoelectric sensor 12 has a power line. A sensor operating current is supplied by a multi-drop method or the like by 13, and each photoelectric sensor 1
2 illuminates each parking area 11 and each parking area 11
The parking condition of the car is detected.

Since each vehicle sensor 12 and the central control unit 2 for controlling the entire system are connected to each other via a dedicated or multi-drop communication cable 15, the parking state detected by each photoelectric sensor 12 is detected. Are sent to the central control unit 2 for aggregation, and the parking state in all the parking areas of the parking lot is displayed on the display unit 3.

[0007]

However, in a parking state detection system that counts when entering and leaving a parking lot, a cumulative error may occur in the number of counts, and it is necessary to correct the error from time to time, and at the same time, in each parking area. When it is attempting to detect such a parking state, it is not possible to display the parking state such as which parking area is empty because it has not detected the parking state in However, there is a problem in that it is necessary to provide another detection means.

Further, in the conventional parking state detection system for detecting the parking state for each parking area, it is possible to display which parking area is in an empty state, but each photoelectric sensor 12 and the central control unit 2 can be displayed. Since they were individually connected via the communication cable 15, the number of photoelectric sensors 12, that is, the number of the communication areas 15 corresponding to the number of the parking areas 11.
Need to be provided. Therefore, when the number of parking lots increases, it is necessary to add the communication cables 15 by that amount, which causes a problem that the cost increases and the wiring work and maintenance management become complicated and increase.

Further, in the multi-drop method, when a disconnection or a short circuit occurs in the communication path, a number of related failures occur, which is not preferable for maintenance.

Therefore, the present invention has been made in view of such a problem, and can detect even the parking state in each parking area, and even if the number of parked vehicles is increased by reducing the wiring of communication cables, the cost and It is an object of the present invention to provide a parking state detection system capable of preventing an increase in the burden of wiring work maintenance and the like.

[0011]

In order to achieve the above object, in the present invention, the electric power from a common or common electric power line is used to detect the parking state of each parking area in a parking lot, and the entire parking area is detected. In the parking state detection system that is designed to determine the parking state of each parking area, the parking state is provided for each parking area, illuminates each parking area with light, and receives the reflected light from the floor of each parking area A plurality of optical sensors for detecting, and is attached to each parking area floor surface so as to correspond to each of the optical sensors,
A reflector that reflects the light beam transmitted by each optical sensor toward each optical sensor of the transmission source, and each optical sensor and power line and signal line that are provided for each of a predetermined number of parking areas and are provided in each parking area. Connected to the modem by a power line, by power line communication via the modem, and transmits a sensor operation command to the plurality of optical sensors, the parking state signal detected by the plurality of optical sensors A central control unit that collects and obtains the parking state of all parking areas.

[0012]

The central control unit transmits power to each optical sensor according to a preset order by power line communication via the modem, and causes each optical sensor to operate in that order to detect the parking state in each parking area. , Collecting the detected parking condition signals to obtain the parking condition of all parking areas.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A parking condition detection system according to the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of the system configuration of this system.

In the parking lot 1 using the power from the common or common power line 23, the present system uses the power line communication system so that the parking area 11 where the vehicle 14 is parked is "presence". It is intended to detect the parking state whether it is a "vehicle" or an "empty vehicle". The central control unit 2 and a plurality of optical sensors 25 installed on the ceiling or the like of each parking area 11 are used. It is characterized by being connected by a power line 23 via several slave modems 24.

The optical sensor 25 is a reflection type sensor having a transmitting section and a receiving section, and the irradiation light from the optical sensor 25, which will be described later with reference to FIG. A reflective reflector 25 is attached.

In the present embodiment, the slave modem 24, as shown in the figure, is connected to seven parking areas 11 together with individual communication lines to form one section. The power line 23 and the communication line 23a are laid out in a multi-drop manner so as to be able to supply power to 25, and the sensor operation command sent from the central control unit 2 by power line communication using this power line 23 is set to the command. Each optical sensor 25 is transmitted to each optical sensor 25 via the communication line 23a in accordance with the designated sub-address.
Is stored as parking information.

The central controller 21 controls each slave modem 24.
And a master modem 21a connected by a power line 23,
By a power line communication using the power line 23 via the master modem 21a, a sensor operation command for transmitting to each slave modem 24 a sensor operation command in which a node address of each slave modem 24 and a sub address of each optical sensor 25 are set as described later. 21b and parking information collecting section 21c
Have and.

The parking information collecting unit 21c communicates with each slave modem 24 by power line communication using the power line 23, for example, by a 1: n polling selection method at a communication speed of 9600 bps, and each slave modem 24. Is configured to collect the parking information held by the vehicle, determine the parking state of each parking area 11, and display the parking state on a plurality of display units 3. In addition, in the present embodiment, description will be made assuming that the parking information is determined by the parking information collecting unit 21c. However, in the present invention, in addition to this method, the optical sensor 2 is used.
When the slave modem 24 signal-processes the reception level detected by 5 into parking information, it may be compared with a threshold value described later and the comparison result may be used as parking information.

FIG. 2 shows an example of the configuration of modems used as the slave modem 24 and the master modem 21a.

The hardware configuration of the slave modem 24 and the master modem 21a is the same. The difference is that the setting mode in the mode setter is set to "slave" or "master", which will be described later. Further, in the case of the slave modem 24, the optical sensor 25 managed by the slave modem 24 is connected, and the program for operating it is stored. Explain.

The modem 24 is connected to the power source transformer Tr24a directly connected to the power line 23 and the primary side of the power source transformer 24a via the carrier path capacitors C1 and C2, and has a function of separating a received signal from an AC power source. An isolation unit 24b having a function of superimposing a transmission signal on the AC side, and a digital logic circuit (D
LC: Digital Logic Controller) 24c, isolation unit 24b, and carrier path capacitor C
Data link level power line modem (including output line) that is connected via 3 and C4 and communicates in spread spectrum (SS) system (9600bps to 100kbps)
Data Link Processor (DLP) 24 that functions as
d, isolation unit 24b, DLP 24c
And a DC power supply 24e for transmitting a driving stabilizing current to the DLP 24d.

The digital logic circuit (DLC) 24
Although not shown, C is a CPU, a ROM, a RAM, an address setting unit, a mode setting unit, and IN and OUT are each 24 b.
It has an I / O port for it and an interface such as RS232C, and is configured to control the entire modem.
When this modem is used as the slave modem 24, the mode setter is first switched to the "slave" side as described above, and the seven optical sensors 25 managed by this modem in advance via the interface of the DLC 24c. The CPU is connected to the ROM, which will be described in detail later.
Transmits to each of the seven optical sensors 25 while switching the sensor operation command according to the sub-address designated by the sensor operation command unit 21b, and each optical sensor 2
A program for operating so that the parking state detected by 5 is held in the RAM as parking information is stored.
When using this modem as the master modem 21a, the mode setter may be switched to the "master" side.

FIG. 3 shows the arrangement of the optical sensor 25 and the reflector 26 in this embodiment.

Each optical sensor 25 is installed on the ceiling 1a above the center of each parking area 11 in the parking lot 1. Based on a sensor operation command from the slave modem 24 via the power line 23, each optical sensor 25 is mutually connected. The parking area 11 assigned to each of them is irradiated with a light beam so as not to be affected by interference, that is, the other optical sensor 25, and the reflected light from the irradiated light is received to detect its level. . The optical axis (mounting angle) of each optical sensor 25 with respect to the parking lot floor surface 1b is set to be slightly tilted from the vertical direction so that the reflected light from the vehicle 14 does not directly return.

The reflector 26 is replaceably attached to the optical axis of the optical sensor 25 on the floor surface 1b of each parking area 11, and its structure and function will be described with reference to FIG.

FIG. 4 shows an example of a sectional structure of the reflector 26.

A reflector 26 having a sectional structure as shown in the drawing.
Is a reflector such as a reflector or a tape provided on the rear part of the bicycle or the like, which reflects the light from the vehicle during night driving to attract the driver's attention.
The structure in which the sheet 6a is covered with a resin sheet material such as transparent plastic or tape, or transparent glass is used, and the reflector 26a reflects the incident light beam, and most of the reflected light is reflected. Is configured so that it can be reflected in the incident direction.

Therefore, the reflector 2 having such a structure is used.
In the case of No. 6, even if the light sensor 25 is not accurately pasted on the optical axis, or if there is some deviation in the pasting position or angle and no light beam is incident vertically on the surface of the reflector 26, the reflected light is It can be attributed to the light sensor 25 of the transmission source.

The other structure of the reflector 26 may be a plane or convex reflecting mirror.
In either case, the position and angle of the reflecting mirror must be precisely adjusted so that the reflected light returns to the sensor of the transmission source. Further, it is necessary to consider the surface of the reflector 26 such as dirt and proof stress.

Next, the operation of the parking state detection system thus constructed will be described with reference to the drawings.

First, referring to FIG. 1, the master modem 21a
By the power line communication via the power line 23 and the power line 23, the sensor operation command is transmitted from the sensor operation command unit 21b of the central control unit 21 to each slave modem 24 in a predetermined order, and at the same time in each parking area 11. In order to detect the parking state for each time, a polling frame is transmitted from the parking information collection unit 21c at each predetermined time.

In each slave modem 24, the DLC 24c
(See FIG. 2) receives the sensor operation command addressed to its own node (modem), selects the optical sensor 25 managed by itself based on the subaddress set as described later, and transmits the sensor operation command, Each light sensor 25 is caused to transmit a light beam and receive its reflected light.

The light beams emitted from the respective photosensors 25 may be operated at the same time as long as the photosensors 25 do not interfere with each other, that is, the other photosensors 25 do not interfere with each other. If so, the optical sensors 25 are operated one by one.

By the way, each optical sensor 25 which receives the reflected light from the light beam emitted by itself detects the reception level at the time of reception, performs signal processing such as binarization, and manages each as parking information. Slave modem 24 DLC2
It is held in a RAM or the like in 4c.

Each time the slave modem 24 receives a polling frame from the parking information collecting unit 21c, it selects the optical sensor 24 according to the sub-address set in the polling frame and outputs the parking information of the optical sensor 24. The parking information is read from the RAM or the like, and the parking information is placed on the response frame and sent to the parking information collecting unit 21c.

In the parking information collector 21c, the power line 23,
And by power line communication via the master modem 21a,
A response frame is received from each slave modem 24, the parking information included in the response frame is extracted, and the parking state in each parking area 11 is determined.

The determination of the parking state is made by comparing the reception level indicated by the parking information with a threshold value between the reception level when the vehicle is in the on-vehicle state and the reception level when the vehicle is in the empty state. By.

That is, from the optical sensor 25 to each parking area 1
When the vehicle is in the presence state, the light beam radiated toward 1 may be absorbed when it hits the vehicle or may be reflected in a direction different from the direction of the optical sensor 25 of the transmission source. However, it may return to the optical sensor 25 when reflected.

However, the reception level of the reflected light from the vehicle 14 when the vehicle 14 is in the in-vehicle state is the same as the optical sensor 2 when the vehicle 14 is in the empty state.
Since the reception level of the reflected light from the reflector 26 in 5 is sufficiently small, the reception level of the reflected light when the vehicle is in the vehicle state and the reception level of the reflected light when the vehicle is in the vacant state are measured in advance. , A value between them is stored as a threshold value, and the parking state can be determined by comparing the threshold value with the detected reception level. That is, when the detected reception level is lower than the threshold value, it is determined that the parking area 11 is in the on-vehicle state, whereas when the detected reception level is higher than the threshold value, the parking area 11 is determined.
Is determined to be empty.

Then, in the parking information collecting section 21c, after judging the parking state in each parking area 11, the display section 3
In which parking area 11 is “in-vehicle”
The parking state of each parking area 11 such as whether it is in a state or in an "empty" state is displayed, and which optical area 25 of the parking area 11 is "faulty" or "normal" is displayed. I do.

In the polling selection method communication, usually, in addition to the subaddress for selecting each optical sensor 24, the node address of the slave modem 25 indicating the transmission destination and the transmission source of the frame is set in the polling frame and the response frame. Therefore, in the parking information collection unit 21c, when the response frame is received, if there is a slave modem 24 that cannot receive the response frame even after the response limit time elapses, the response limit time is exceeded, The failure of the slave modem 24 can be detected by detecting an abnormality due to resending, and this may be displayed on the display unit 3.

Therefore, according to the present embodiment, since the parking state in each parking area 11 is detected by the power line communication using the power line 23, the communication cable for collecting the parking state in each parking area is provided at the center. Control unit 21
It is not necessary to provide it between the optical sensor 25 and the optical sensor 25, and the wiring can be saved.

Therefore, even if the number of parked cars increases,
This can be dealt with by slightly increasing the number of power lines, installing the group communication line 23a, and additionally setting the node address and sub-address in the central control unit 21, thus preventing an increase in cost and burden of wiring work.

Further, in this embodiment, since the reflection type optical sensor 25 and the reflector 26 attachable to the floor surface 1b are used as means for detecting the parking state of each parking area 11, the floor surface 1b is used. Since it is not necessary to provide a receiving portion for receiving the light beam from the optical sensor 25 and it is not necessary to bury the reflecting portion in the floor surface 1b, the cost can be reduced in terms of maintenance and construction.

In the present embodiment, it is described that the determination of the parking state is made based on the comparison with the predetermined fixed threshold value. However, in the present invention, the parking state and the presence state of the vehicle are received instead of the fixed threshold value. For the level, for example, the moving average of the latest 10 or 20 times is taken, and the optimal threshold value is calculated at any time based on the moving average value of both levels, and the parking state is judged based on this value. May be.

In this way, the threshold value is a value that takes into consideration the latest road surface condition, for example, the condition of dust on the road surface, water wetness, mud, etc., so that a more accurate road surface condition can be obtained. You will be able to judge the state.

[0048]

As described above, according to the present invention, an optical sensor is provided for each parking area, and each optical sensor and the central control unit are connected by a power line via a modem, and the central control unit operates the modem. Since the sensor operation command is transmitted to each optical sensor by power line communication via the vehicle, the parking states detected by each optical sensor are collected and the parking states of all the parking areas are obtained, so the parking states of each parking area are collected. There is no need to provide a communication cable between the central control unit and each sensor, and wiring can be saved.

Therefore, even if the number of parked cars increases,
This can be dealt with only by adding a few power lines and communication furnaces, etc., and it is possible to prevent an increase in cost and burden of wiring work.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a system configuration of a parking state detection system according to the present invention.

FIG. 2 is a block diagram showing a configuration of a slave modem.

FIG. 3 is an explanatory diagram showing an operating state of an optical sensor.

FIG. 4 is an explanatory view showing an example of a sectional structure of a reflector.

FIG. 5 is an explanatory diagram showing an example of a conventional parking state detection system.

[Explanation of symbols]

 1 Parking Lot 3 Display 11 Parking Area 14 Vehicle 21 Central Control 23 Power Line 24 Slave Modem 25 Optical Sensor

Claims (1)

[Claims] 1. A parking state detection system for detecting a parking state of each parking area in a parking lot by using electric power from a common or common electric power line to obtain a parking state of all parking areas. Each parking area is provided with a plurality of light sensors for illuminating each parking area with light and receiving reflected light from each parking area floor surface to detect a parking state in each parking area, and each parking area floor. A reflector that is attached to the surface so as to correspond to each of the above-mentioned optical sensors, and that is provided for each of a predetermined number of parking areas, and a reflector that reflects the light beam transmitted by each optical sensor toward each of the light sensors of the transmission source. A modem connected to each optical sensor provided in each parking area by a power line and a signal line, and a modem connected to the modem by a power line for power line communication through the modem. A central control unit that transmits a sensor operation command to the plurality of optical sensors and collects parking state signals detected by the plurality of optical sensors to obtain a parking state of all parking areas. Parking condition detection system.