JP3419087B2 - Communication device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication apparatus for performing communication between a mobile station and a fixed station provided on a mobile body. 2. Description of the Related Art In recent years, there has been proposed a communication apparatus which collects a fee without stopping a vehicle, for example. This is a tag unit (mobile station) for vehicles traveling on toll roads
And an antenna unit (fixed station) with a communication area set in the traffic lane to reduce the charges stored in the tag unit by communicating between the tag unit and the antenna unit. is there. [0003] Incidentally, in order to correspond to a toll road in which a plurality of traveling lanes are set, it is necessary to install an antenna unit corresponding to each lane, and to deal with a vehicle traveling across the lanes. It is necessary to set adjacent communication areas in a partially overlapping state. For this reason, in a configuration in which communication between the antenna unit and the tag unit is performed simultaneously, mutual interference occurs. Therefore, Japanese Patent Application Laid-Open No. 2-93
In the device disclosed in Japanese Patent No. 390, the communication time of the antenna unit is time-divided by sequentially allocating the communication time.
In other words, the antenna unit shifts to the communication standby state when the communication of the antenna unit with the higher priority ends, and starts communication with the tag unit when the tag unit enters the communication area during the communication standby state, When a predetermined time has elapsed from the start of the communication standby state, the lower priority antenna unit is shifted to the communication standby state. Therefore, since the antenna unit and the tag unit do not communicate at the same time, interference can be prevented. [0004] However, in the above-described conventional configuration, the antenna unit is configured to terminate communication when a predetermined time has elapsed from the start of the communication standby state. Therefore, depending on the communication start position between the tag unit and the antenna unit in the communication area, there is a disadvantage that the communication process is interrupted due to a short communication time. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a communication apparatus capable of reliably performing communication processing in a configuration in which communication between a fixed station and a mobile station is performed in a time-division manner. To provide. SUMMARY OF THE INVENTION The present invention relates to a moving object
Adjacent communications with some overlapping so as to cross the road
An area is set, and the fixed station communicates with a mobile station provided in the mobile body, wherein the fixed station is in a communication standby state when a communication end signal is input from a fixed station having a higher communication order. When the communication standby state for a predetermined period of time ends, the communication ends and the fixed
A communication end signal is output, and when communication with the mobile station is started in a communication standby state, the communication end is extended until communication processing with the mobile station ends. In the case of the communication device according to the first aspect, the fixed station transmits a communication end signal from a fixed station having a higher communication order.
Passing together when you enter a No. shifts to communication standby state, when the communication standby state for a predetermined time is finished and ends the communication
The communication end signal is output to the fixed station having the lower priority. Do
And the fixed station with the lower communication order shifts to the communication standby state.
You. As a result, the fixed station enters a communication standby state in a time-division manner.
You. Now, when the fixed station is in the communication standby state,
When the mobile enters the communication area of the fixed station, the fixed station and the mobile station start communicating. At this time, the fixed station extends the communication end until the communication processing ends . By this, fixed
Fixed stations are time-divisionally driven by signal connection between stations
And can reliably process communications.
Therefore, when increasing or decreasing the number of fixed stations,
Can be dealt with simply by changing An embodiment in which the present invention is applied to a toll road toll collection system will be described below. FIG. 2 shows the appearance of a gate provided on a toll road. In FIG. 2, a toll road 1 is provided with a plurality of lanes, and a gate 2 is provided so as to straddle the toll road 1. The gate 2 is provided with a plurality of antenna units 3 as fixed stations, and a communication area of microwaves from the antenna unit 3 (an area indicated by a two-dot chain line in the figure) is set for each lane. I have. In this case, each communication area is set so as to cross a toll road, and set so that a part of an adjacent communication area overlaps. This is to enable communication even when the vehicle 4 as a moving body traveling on the toll road 1 runs across a lane. FIG. 3 schematically shows the entire structure. 3, each antenna unit 3 is connected to a controller 5. The controller 5 controls transmission and reception of the antenna unit 3 and exchanges communication data with the host computer 6. Here, a tag unit 7 (see FIG. 1) as a mobile station is mounted on the vehicle 4, and when the vehicle 4 enters a communication area, the tag unit 7 and the antenna unit 3 communicate with each other. It has become. FIG. 1 shows the antenna unit 3 and the tag unit 7 in functional blocks. Note that the connection between the antenna unit 3 and the host computer 6 is omitted for simplification of the description. In FIG. 1, the antenna unit 3 includes a timer 8, a timer input control unit 9, and an antenna communication unit 10. Here, the antenna unit 3 is connected to the adjacent antenna unit 3, and the priority is set by the connection. That is, in the antenna unit 3, the timer 8 is connected to the antenna communication unit 10 of the antenna unit 3 having a higher communication order, and receives a communication unit drive end signal from the antenna communication unit 10. In this case, when the communication unit drive end signal is input, the timer 10 outputs a timer signal to the antenna communication unit 10 through the timer input control unit 9. The antenna communication unit 10 shifts to a communication standby state when a timer signal is input, and outputs a communication unit drive end signal to the timer 8 of the antenna unit 3 with a lower communication order when the input of the timer signal ends. It has become. When the antenna communication unit 10 receives a response signal from the tag unit 7 in the communication standby state, the antenna communication unit 10 outputs a communication start signal to the timer input control unit 9 to invalidate the input of the timer signal. When the communication with the unit 7 is completed, a communication unit drive end signal is output. In addition, the timer input control unit 9 controls the antenna communication unit 1 while outputting the timer signal to the antenna communication unit 10.
When a communication start signal is input from 0, output of the timer signal is prohibited. On the other hand, the tag unit 7 is mainly configured by a mobile communication unit. FIG. 4 schematically shows the electrical configuration of the antenna communication unit 10 of the antenna unit 3, the controller 5, and the mobile communication unit of the tag unit 7. That is, in the antenna communication unit 10, the modulation circuit 11
An oscillation signal of a predetermined frequency given from the controller 5
Circulator 13 by modulating with the interrogation signal given from
Is output to the antenna 14 via. The mixer 15 modulates the reception signal input from the antenna 14 through the circulator 13 by combining the reception signal with the carrier signal from the oscillator 12, and supplies the modulated signal to the reception circuit 16. The receiving circuit 16 obtains a response signal corresponding to the interrogation signal by demodulating the combined signal provided from the mixer 15, and outputs the response signal to the controller 5. In the controller 5, the unit control circuit 17 is connected to the modulation circuit 11 and the reception circuit 16 of each antenna communication section 10, and outputs an interrogation signal to the modulation circuit 11 at a predetermined timing. Is input. The unit control circuit 17 is connected to the host computer 6 via the interface circuit 18. On the other hand, in the mobile communication section of the tag unit 7, when the control circuit 19 receives the interrogation signal received from the antenna 21 through the reception circuit 20, it receives the identification code stored in the data memory 22 in response to the interrogation signal. The transmission circuit 23 uses various data such as the paid fee and the like as a response signal.
Through the antenna 21. Then, the battery 24 supplies power to each circuit constituting the mobile communication unit. Next, the operation of the above configuration will be described. FIG. 5 shows the operation of the antenna unit 3. This figure 5
, When the communication of the antenna unit 3 positioned higher in the communication order ends, a communication unit drive end signal is output from the antenna unit 3 to the timer 8. Then, since the timer 8 is driven when the communication unit drive end signal is input (steps S1 and S2), a timer signal is output from the timer 8 to the antenna communication unit 10 through the timer input control unit 9, and the antenna communication is accordingly performed. The unit 10 is driven (Step S3). In this case, during the period in which the interrogation signal is not supplied from the host computer 6, the antenna unit 3 does not perform modulation by the modulation circuit 11, so that the carrier signal from the oscillator 12 is not modulated. The signal is transmitted from the antenna 14 to the corresponding communication area as it is. Then, when the antenna unit 3 is enabled, the host computer 6 transmits an interrogation signal by a carrier signal. When the vehicle 4 does not enter the communication area, the antenna unit 3 does not communicate with the tag unit 7 mounted on the vehicle. Elapse (Step S
4, S5). Then, since the driving of the timer 8 is stopped, the output of the timer signal from the timer 8 is stopped. As a result, the antenna communication unit 10 stops (step S
6) Accordingly, a communication unit drive end signal is output from the antenna communication unit 10 to the antenna unit 3 with a lower communication order (step S7). As a result, the antenna unit 3 having the lower communication order operates in the same manner as described above, and shifts to the communication standby state. By the above operation of the antenna unit 3, the antenna unit 3 operates in a time-division manner as shown in FIG. Now, when the vehicle 4 enters the communication area,
Since the tag unit 7 receives the interrogation signal transmitted from the antenna unit 3, a response signal corresponding to the interrogation signal is returned from the tag unit 7. At this time, when the response signal is input in the input state of the timer signal (step S4), the antenna communication unit 10 outputs the communication start signal to the timer input control unit 9, thereby invalidating the output of the timer signal and (Step S8), a communication process is executed (Step S9). As a result of the above operation, the antenna communication unit 10
Is driven until the communication processing with the tag unit 7 mounted on the vehicle that has entered the communication area is completed.
Communication processing with the tag unit 7 can be reliably performed. In this communication process, the identification code set in the tag unit 7 is confirmed, and when the identification code is legitimate, the paid fee stored in the tag unit 7 is reduced by the toll fee to reduce the fee. A collection is made. According to the above configuration, when the antenna unit 3 starts communication with the tag unit 7 when the antenna communication unit 10 is in the communication standby state in response to the driving of the timer 8, Since the configuration is such that the timer 8 is invalidated, the antenna unit 3 can reliably perform communication processing with the tag unit 7. Therefore, unlike the configuration in which the antenna unit communicates with the tag unit by simply driving the antenna unit in a time-division manner, the communication between the antenna unit 3 and the tag unit 7 is performed regardless of the communication start position in the communication area. Processing can be executed reliably. The present invention is not limited to the above embodiment, but can be modified or expanded as follows. The antenna unit 3 may be time-divided by the controller 5. Information on a conveyed object may be transmitted by communication with a tag unit mounted on an automatic guided vehicle. The present invention may be applied to an entrance / exit of a station or an automatic ticket gate at a ski resort to determine the validity of traffic by communication with a tag unit carried by a person.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a functional block diagram showing a configuration of a main part according to an embodiment of the present invention. FIG. 2 is a perspective view showing a gate extending over a road for a fee. FIG. 4 is a schematic diagram showing an electrical configuration of a main part. FIG. 5 is a flowchart showing an operation of the antenna unit. FIG. 6 is a timing chart showing a communication standby state of the antenna unit. 3 is an antenna unit (fixed station), 4 is a vehicle (mobile), and 7 is a tag unit (mobile station).

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G07B 15/00

Claims (1)

(57) [Claims] [Claim 1] Partly so as to cross the traveling path of the moving body
Is set communication areas adjacent in a overlapped state, the a fixed station that communicates with the transfer <br/> mobile station provided on the moving body, the fixed station, the communication order is the fixed station of the upper Communication end signal
Passing together when you enter a No. shifts to communication standby state, when the communication standby state for a predetermined time is finished and ends the communication
It is configured to output a communication end signal to a fixed station having a lower priority and to start communication with the mobile station in a communication standby state until communication processing with the mobile station ends. A communication device characterized by the above-mentioned.