JPH02171677A - Discriminating system of moving body - Google Patents

Abstract

PURPOSE:To reduce a burden of an upper data processing device by having a transponder unit attached to a moving body and interrogator units communicating in a non- contact manner with the transponder unit being present in the area of communication and by making the interrogator units in a plurality operate on a time-division basis. CONSTITUTION:It is assumed that communication areas S of an interrogator units 11 and 12 overlap each other and that communication areas S of other interrogator units 13 to 1N overlap one another while communication areas S of other interrogator units 13 to 1N are separate from one another. If a controller or a user of a system inputs from an input device 33 beforehand that the first and second interrogator units 11 and 12 need to be operated on a time-division basis, on the occasion, the interrogator unit 12 is stopped at the time when a transmission stop instruction B is sent at first to the interrogator unit 12. Then, a transmission start instruction A is sent to the interrogator unit 12. After the transmission stop instruction B is sent to the interrogator unit 12, subsequently, the transmission start instruction A is sent to the interrogator unit 11. The same process is repeated thereafter and thereby the interrogator units 11 and 12 are operated alternately. When a interrogation signal is emitted alternately from the opposite sides of a passage, then, it is prevented from interfering with another.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides an interrogator and a transponder that communicate with each other while a transponder installed in a mobile body passes through a communication area of an interrogator installed in a fixed station. This invention relates to a mobile object identification system that identifies mobile objects by communicating with them in a non-contact manner.

[Prior Art] FIG. 3 is a schematic diagram of a conventional general mobile object identification system. The interrogator 1 continuously or intermittently sends out interrogation signals using signal waves such as radio waves, light, sound waves, and magnetic lines of force within the communication area S. When the transponder 2 installed in a mobile object enters the communication area S of the interrogator 1, the transponder 2
receives the interrogation signal sent from the interrogator 1 and returns a response signal according to the content of the interrogation signal. If the transponder 2 only has the function of returning information such as an identification signal, communication ends at that point, but if the transponder 2 has a built-in storage device, the communication from the interrogator 1 to the transponder ends. Operations are performed in accordance with each command such as a write command (data write command) and a read command (data read command) transmitted to the controller 2. The control device 3 performs operations such as controlling commands sent from the interrogator 1 and operating time, and processing data received from the transponder 2. The control device 3 may be provided with an interface for connecting to an upper host computer, or may operate independently.

By the way, in a mobile object identification system, there is an application in which a plurality of interrogators 1 are installed in a distributed manner to monitor the current position of a mobile object to which a transponder 2 is attached. In this case, as shown in FIG. 4, one control device 3 is often configured to control a plurality of interrogators 1 at the same time.
The control device 3 shown in FIG. 4 can determine not only the identification number of the transponder 2 but also the identification number of the interrogator 1 that has communicated with the transponder 2. It is transmitted or displayed on a display panel.

[Problems to be Solved by the Invention] As shown in FIG. An interrogation signal is sent to the transponder 2 according to the command taken. At this time, if the individual interrogators 1 are installed sufficiently apart from each other and the communication areas S of the interrogators 1 do not overlap, normal communication operation is guaranteed. If operated in a situation where the areas S overlap, the interrogation signals sent from the individual interrogators 1 will cause crosstalk, interference, etc., making it impossible to perform normal communication operations.

In order to avoid such problems, it is conceivable to control each interrogator 1 to operate in a time-sharing manner by the data processing device 4 connected to the upper layer, as shown in FIG. In order to adjust the operation timing of multiple interrogators 1, it is necessary to constantly send transmission start commands and transmission stop commands to each control device 3. This means that the upper data processing device 4 (-most This places a heavy burden on the host computer (especially the host computer) and slows down the overall system operation speed.

The present invention has been made in view of these points, and its purpose is to prevent interrogation signals from causing crosstalk or interference even when multiple interrogators are used in close proximity. An object of the present invention is to provide a mobile object identification system.

[Means for Solving the Problems] In order to solve the above problems, the mobile object identification system according to the present invention includes a transponder 2 attached to a mobile object,
An interrogator 1 that communicates in a non-contact manner with a transponder 2 existing in a communication area S, a control device 3 that operates a plurality of interrogators 1 in a time-sharing manner so that their operating times do not overlap, and a control device The device is characterized by comprising a data processing device 4 that performs data transmission and reception operations with the interrogator 1 via the device 3.

[Operation] In the mobile object identification device of the present invention, since the control device 3 itself controls the plurality of interrogators 1 to operate in a time-sharing manner, even if the communication areas S of the interrogators 1 overlap, The interrogation signal from the transponder 2 and the response signal from the transponder 2 do not cause interference or interference, and do not impose a burden on the upper-level data processing device 4.

[Embodiment] FIG. 1 shows the hardware configuration of a control device 3 used in an embodiment of the present invention. In FIG. 6, 31 is a microprocessor, 32 is an interface with the data processing device 4, and 33 is an input device. It is a device.

The data processing device 4 includes, for example, an upper host computer, a network, a personal computer, and the like.

Also, alJ+ is the first interrogator 1. 182+b2 are the data output line and data input line for the second interrogator 1□, and similarly, aH and bH are the data output line and data input line for the N-th interrogator I.
These are data output lines and data input lines for N.

FIG. 2 is a time chart showing the operation of this embodiment.9
In the figure, horizontal axes X1 to XN are time axes indicating the timing of signal output from each data output line a to aN. Further, the horizontal axis X0 is a time axis indicating the timing of signal output from the data processing device 4 to the control device 3. A is an individual interrogator 11
B is also a command to stop transmitting an interrogation signal, which is given from the control device 3 to each of the interrogators 11 to IN. C is a system operation start command received by the interface 32. In this operation example, the communication areas S of interrogator II and interrogator 12 overlap, and other interrogators 1. ~IN communication areas S are assumed to be independent. At this time, the system administrator or user inputs from the input device 33 that it is necessary to operate the first and second questions 11 and 1□ in a time-sharing manner. The microprocessor 31 has an interface 3
When the system operation start command C is received through the interrogator 2, the command is sent to each of the interrogators 11 to IN through the data output lines a, to aH. In this operation example, the microprocessor 31 is preset from the input device 33 that there is a combination of the interrogators 11 and 12 that needs to be operated in a time-sharing manner, so for the data output line al+82,
Transmission start commands A and transmission stop commands B of interrogation signals are sent alternately, and interrogators II and 1□ are operated alternately. Specifically, when the transmission start command A is first sent to the interrogator 1,
Interrogator 12 is stopped. Next, after sending a transmission stop command B to the interrogator 11, a transmission start command A is sent to the interrogator 1□. Then, after sending a transmission stop command B to the interrogator 12, a transmission start command A is sent to the interrogator 11. below,
The same process is repeated, and interrogator 1° and interrogator 12 operate alternately. Therefore, for example, interrogator 1.
Even when the interrogators 11 and 12 are arranged facing each other on the walls on both sides of the passageway to communicate with the transponder 2 attached to a moving object passing through the passageway, the interrogation signals of the interrogator 11 and the interrogator 1□ will not interfere with each other. There will be no more interference. In this way, by alternately emitting interrogation signals from both sides of the passageway, good communication conditions can be obtained no matter which side of the moving body the transponder 2 is attached to. The switching cycle of the operating times of the interrogators 11 and 12 depends on factors such as the moving speed of the transponder 2 installed in the mobile object and the length of communication time between the transponder 2 and the interrogators 18 and 1□. All you have to do is decide. Also, other interrogator 1
．． ~IN does not need to be operated in a time-division manner, so the microprocessor 31 generates the interrogation signal transmission start command A in response to the system operation start command C, and directly transmits the interrogator 1. ~Continue the operation of IN.

[Effects of the Invention] According to the present invention, multiple interrogators are controlled to operate in a time-sharing manner, so that even if the communication areas of the interrogators overlap, multiple interrogators can be operated without interference or interference. The control for operating multiple interrogators in a time-sharing manner is performed by the interrogator control device itself, which eliminates the burden on the upper data processing device. There is.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the hardware configuration of the present invention,
Fig. 2 is an operation explanatory diagram showing the same operation as above, Fig. 3 is a block diagram showing the schematic structure of the conventional example, Fig. 4 is a block diagram showing the schematic structure of another conventional example, and Fig. 5 is the block diagram showing the schematic structure of the conventional example. It is a block diagram for explaining a problem. 1, . . . , -IN are distillers, 2 is a responder, 3 is an M control device, 4 is a data processing device, and S is a communication area.

Claims (1)

[Claims] (1) A transponder attached to a mobile object, an interrogator that communicates non-contact with transponders existing within the communication area, and multiple interrogators in a time-sharing manner so that their operating times do not overlap. What is claimed is: 1. A mobile object identification system comprising: a control device that operates the system; and a data processing device that transmits and receives data to and from an interrogator via the control device.