JPH08249595A - Bus arrival guidance system - Google Patents

Abstract

PURPOSE: To eliminate a communication defect caused by interference in a system where the position of a bus is displayed and announced inside the bus by the radio communication with a bus stop. CONSTITUTION: A bus on regular route is provided with a radio wave reception time counting means 11 for counting the reception time of radio waves generated by the other system at the time of waiting reception and a transmission cycle preparing means 12 for changing a transmission cycle for communication to be long/short corresponding to whether the counted radio wave reception time is long or short in addition to a specified small power radio equipment 2 for communication and based on that transmission cycle, a communication control means 3 decides the timing of transmission.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is based on radio communication between a local bus and a nearest bus stop, and displays the bus position at the bus stop or on-board the bus for guiding the bus stop. Bus arrival information system for making announcements.

[0002]

2. Description of the Related Art As a system for making an in-vehicle announcement based on communication with a stop, for example, Japanese Patent Application No. 6-
No. 318046, “In-vehicle announcement method and device for route bus”, and the following is introduced as the “bus position display system” for displaying the bus position at a stop in the above application specification.

Japanese Unexamined Patent Publication No. 2-119797 "Bus Arrival Notification Device": When a user pushes a push button at a bus stop, a predetermined signal is transmitted to the bus while relaying the bus stops one after another, and the bus receiving the signal Sends a response signal, and the response signal follows the reverse route and is relayed to the bus stop waiting for the user, and the number of relays at this time is taken as the bus position of how many buses the bus stop is before. indicate. [Patent Document 1] Japanese Unexamined Patent Publication No. 2-177000 "Mobile object approaching system": A transmitter is mounted on a school bus, while a receiver is installed at home, and when a signal transmitted from the school bus is received, it is determined that the school bus is approaching. Inform. Japanese Unexamined Patent Publication No. 4-249898 “Route bus operation monitoring control system”: The route bus communicates wirelessly with the nearest bus stop, and the bus stop transmits the contents of the communication to the center control device through a communication line. The center controller monitors the operating status of the route bus in real time. [Patent Document 1] Japanese Patent Application Laid-Open No. 5-174295 “Bus approach notification method and device”: The approach of a route bus is known at home, and the configuration is the same. Japanese Unexamined Patent Publication No. 6-12593 "Arrival time prediction system": When a destination is input by a terminal mounted in a vehicle, the data is wirelessly transmitted to a host computer, and the host computer takes a route to the destination. We collect the traffic conditions at each intersection wirelessly and calculate the time required to reach the destination based on the traffic conditions.
Send to the terminal.

[0004]

In such a bus arrival guidance system, communication is normally carried out between a bus and a stop according to a fixed cycle, and therefore, a bus terminal or a traffic jam where many buses always stay. As a result, a large number of buses concentrate in a specific area, resulting in an increase in traffic volume of wireless communication, resulting in interference and communication abnormality.

The present invention has been made to solve the above-mentioned problems, and it reduces interference by detecting the traffic volume of radio communication and changing the communication cycle according to the detected traffic volume. , It aims to enable efficient communication.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a specific low power radio 2 and a transmission / transmission of the specific low power radio 2 to a route bus.
The communication control means 3 for controlling reception is provided, and communication is performed with the bus station at a fixed cycle. Based on the content of the communication, the current position of the bus route is displayed at the bus station, or the bus stop name is displayed in the bus route. In the stop arrival guide system that announces in a car, the above-mentioned route bus is a radio wave reception time counting means 11 for counting the reception time of a radio wave emitted by another system, and a radio wave obtained by the radio wave reception time counting means 11 while waiting for reception. A transmission cycle creating means 12 for changing the transmission cycle to long / short according to the length / shortness of the reception time, and the communication control means 3 transmits based on the transmission cycle created by the transmission cycle creating means 12. It is characterized by determining the timing.

[0007]

FIG. 1 shows a claim correspondence diagram of the first invention according to claim 1, and the basic operation of the "stop arrival guide system" adopted in FIG. 1 will be briefly described.

[0008] The route information stored in the route information storage means 1 of the bus A is transmitted to the stop B by the specific low power radio 2 and the communication control means 3 for controlling this, and the route information is specified by the specific small information of the stop B. It is received by the electric power radio 23 and the communication control means 24, and the route identification means 21 determines whether or not the route information corresponds to the stop B, and if the routes match, the stop identification information storage means 22.
Send the stop identification information in memory to. When this is received on the bus A, the bus stop guide information corresponding to the bus stop identification information is sent to the bus stop guide information storage identification 5 by the output control means 6.
Read out from the vehicle and announced by the output means 7.

In such a system, the bus A stands by in a receiving state except during a communication period in which it is carried out at a constant cycle.
Meanwhile, if another system is communicating, the content of the communication is received even on the bus A. If communication from other systems is frequently received in the reception standby state, it is necessary to lengthen the communication cycle in the own system to mitigate interference, while if communication density is low, such Since there is no need to worry, the communication cycle can be made relatively short and detailed communication can be performed. Therefore, the radio wave reception time counting means 11 counts the reception time of the radio wave emitted by another system while waiting for reception, and the transmission cycle creating means 12 transmits the radio wave in this system according to the length / shortness of the time. The cycle is changed to long / short, and the communication control means 3 determines the transmission timing according to the transmission cycle.

The "stop arrival guide system" applied in FIG. 1 is the first invention in the "method and apparatus for in-announcement of a route bus".

As a concrete creating means of the sending cycle creating means 12, each sending cycle creating means 12a, 12b, 12c, 1 described in claim 2, claim 3, claim 4 and claim 5 is used.
2d, which are described in detail in the first, second, third and fourth examples in the examples below.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is a block diagram common to the following embodiments of the present invention. Here, as in the case of FIG. 1, the first invention of the above-mentioned “method and apparatus for in-announcement of route bus” is applied as the “bus arrival guide system”. This will be described in comparison with FIG. The present invention can be applied to other systems.

At stop B, 31 is a CPU having a means for controlling the announcement device as a whole and for identifying the route transmitted from the bus A, and 32 is
It is a ROM that stores a flow control program described later. Reference numeral 33 denotes a RAM that stores stop identification information indicating the stop name and information about a bus route that stops at the stop. Reference numeral 34 is a communication interface for the specific low power radio device 35. On the other hand, on bus A,
Reference numeral 41 denotes a CPU that controls the devices on the bus side,
Reference numeral 2 is a ROM that stores a control program for the CPU.
Reference numeral 43 stores the route information of the bus A and the stop identification information transmitted from the stop B, and also stores data of stop guide information for each stop identification information.
AM. Reference numerals 44 and 45 are a communication interface and a specific low power radio device. Reference numeral 46 is a D / A converter for converting the stop guide information read from the RAM 43 from digital to analog, and 47 is an amplifier for power-amplifying the analog converted stop guide information into a power signal for driving the speaker 48. Is. 49 and 50 are a timer for measuring time and a communication interface for inputting data from the outside.

The above is the configuration according to the first invention of the previous application, but the present invention further includes the following elements. CPU
Reference numeral 41 denotes a reception time counting unit 41A that counts the reception time of the radio wave (carrier) emitted by another system while waiting for reception.
And a transmission cycle creation unit 41B that obtains a transmission cycle based on the counted radio wave reception time.

In this system, bus A and stop B
The communication (transmission) is carried out and the in-vehicle announcement is carried out. The operation at that time is as described in the paragraph [0008]. The present invention is intended to variably set the transmission cycle, and therefore the points will be mainly described in each of the following embodiments.

(First Embodiment) The flowchart of FIG. 3 shows the control operation when the transmission cycle creating means 12a according to the second aspect is provided. Here, the initial value of the transmission cycle is 3 minutes,
The base reception waiting time is 2 minutes. At step S1, it is determined whether or not the transmission timing is reached. _First , the transmission is performed at the start time t ₁ , and then the initial value of the transmission cycle is 3
Transmission is performed at time t ₂ when minutes have elapsed. In this way, when the communication with the stop B is performed in step S2 by transmission, in step S3, the time when the carrier emitted by another system is received is counted, and in step S4, it is determined whether the next transmission timing has come. . When the next transmission timing comes, the process proceeds to step S5. Therefore, in step S3, the radio wave reception time T in the non-communication period within one transmission cycle is counted.

In step S5, the transmission cycle T ₁ for determining the next transmission timing is calculated by 2 minutes (base reception waiting time) + T. As shown in FIG. 4, the radio wave reception time T of the first cycle is 2 minutes. In the case of, the transmission cycle T ₁ is 4 minutes. After this, the process returns to step S2, and the following is the same as the previous time, but the transmission timing used for the determination in step S4 is
From the time t _2, the transmission period T determined in step S5
_It is time t ₃ when ₁ (which was 4 minutes) has elapsed.

The method of counting the radio wave reception time in step S3 is shown in the time charts of FIGS. Figure 5
Then, the CPU 41 determines whether carrier is received or not by interrupting at a cycle of 3 mS, and the number of times of carrier reception is 3 mS.
The radio wave reception time T ₁ is obtained by multiplying by. In FIG. 6, 3
The number of carrier edge rises is counted by interruption of the mS cycle, and the number of counts is multiplied by the time required for carrier reception, for example, 200 mS to obtain the radio wave reception time T ₁ .

(Second Embodiment) The flowchart of FIG. 7 shows the control operation when the transmission cycle creating means 12b according to claim 3 is provided. Again, the initial value of the transmission cycle is 180
Although it is set to seconds, a value called "reception time rate" is introduced. Here, the reception time rate is set to 30%, and in that case,
The non-reception time rate is 70%, but the transmission cycle is 100% as a whole. In step S3 of FIG. 7, for example,
As shown in FIG. 8, the first cycle 180 seconds (initial transmission cycle)
When 60 seconds is counted as the radio wave reception time T in step S6, the transmission cycle T ₂ = 60 seconds + 60 × (70/30) = 200 seconds, that is, the transmission cycle T ₂ = reception counting time (60 seconds) ÷ reception rate (3
0%) = 200 seconds is obtained, and the next transmission timing is at time t _{13 which} is 200 seconds after time t ₁₂ .

(Third Embodiment) The flowchart of FIG. 9 shows the control operation when the transmission cycle creating means 12c according to claim 4 is provided. Here, the specified transmission cycle is 18
0 second is set, the next transmission cycle is set to 180 seconds when the reception rate is 30%, and the specified transmission cycle is adjusted according to the change in the reception rate.

In step S3 ', the radio wave reception time T for the first cycle (this period is 180 seconds of the specified transmission cycle) is counted in the same manner as described above, and the reception rate% is calculated by T / 180. To be done. Then, in step S7, the next transmission cycle T ₃ is obtained from the following equation, and the transmission cycle calculated by this equation is shown in the table below. Transmission cycle T ₃ = specified transmission cycle 180 {1- (30-reception rate%) / 100}

[0022]

[Table 1]

(Fourth Embodiment) The flowchart of FIG.
The control operation when the transmission cycle creating means 12d according to claim 5 is provided is shown. Although Table 1 above shows the transmission cycle with respect to the reception rate%, as shown in this table, an appropriate transmission cycle T ₄ corresponding to the radio wave reception time T is previously stored in the table RO.
It is stored in M, and in step S8, the transmission cycle T ₄ for the radio wave reception time T counted in step S3 is read and the next transmission timing is set.

In FIG. 4 and FIG. 8, the influence of the counted radio wave reception time T is set to 2 minutes and 3 minutes so that the next transmission cycle may change significantly on the time chart. Is several seconds in one communication time, and therefore the radio wave reception time T is rarely several minutes. If the radio wave reception time T reaches several minutes, it is considered to be due to another application (such as a transceiver that uses the same frequency band as the specific low power radio used here). Therefore, when the radio wave reception time T extends over several minutes, it is necessary to determine whether it is due to the operation of the system or due to another application. By the way, since the output of the transceiver by the specific low power radio is as small as 10 mW, if the bus runs for several minutes, it will get out of the communication area. Therefore, when the radio wave reception time T becomes a long time, the data is not immediately adopted, but the initial value of the transmission cycle, for example, is adopted at the next transmission timing, and the long radio wave reception time T is repeated a plurality of times. If it continues, it is determined that it is due to the operation of the system, and in that case, the transmission cycle T ₁ (or T ₂ to T ₄ ) is obtained based on the counted radio wave reception time T, and that may be adopted.

[0025]

[Effects of the Invention] When each route bus is waiting for reception during periods other than the communication period, the reception time of radio waves emitted from other systems is counted to grasp the traffic volume of wireless radio waves in the vicinity, and the traffic volume is large. In this case, the transmission cycle is changed to be longer than itself, so interference can be reduced. On the other hand, when the traffic volume is small, there is no risk of interference, so the transmission cycle is shortened, so it is possible to communicate reliably. Can be done.

[Brief description of drawings]

FIG. 1 Corresponding diagram for complaints of a bus arrival guide system of the present invention

FIG. 2 is a control block diagram showing an embodiment of a bus arrival guidance system of the present invention.

FIG. 3 is a flowchart showing a control operation in the first embodiment of the system of FIG.

FIG. 4 is a time chart showing a control operation in the first embodiment of FIG.

FIG. 5 is a time chart showing a counting method of radio wave reception time shown in FIG.

FIG. 6 is a time chart showing another counting method of radio wave reception time shown in FIG.

FIG. 7 is a flowchart showing a control operation in the second embodiment of the system of FIG.

FIG. 8 is a time chart showing a control operation in the second embodiment of FIG.

9 is a flowchart showing a control operation in the third embodiment of the system of FIG.

10 is a flowchart showing a control operation in the fourth embodiment of the system shown in FIG.

[Explanation of symbols]

 A route bus B stop 31 CPU 31A route identification unit 32 ROM 33 RAM 34 communication interface 35 specific low power radio 41 CPU 41A reception time counting unit 41B transmission cycle creation unit 42 ROM 43 RAM 45 specific low power radio

Claims (5)

[Claims] 1. A route bus is provided with a specified low power radio 2 and a communication control means 3 for controlling transmission / reception of the specified low power radio 2, and communication is carried out with a stop at a constant cycle, Based on the contents of the communication, in the stop arrival information system that displays the current position of the route bus at the stop or announces the name of the stop on the route bus, Radio wave reception time counting means 1 for counting the reception time of emitted radio waves
1 and a transmission cycle creating means 12 for changing the transmission cycle to long / short corresponding to the length / short of the radio wave receiving time obtained by the radio wave receiving time counting means 11, and the transmission cycle creating means 12 A stop arrival guide system, wherein the communication control means 3 determines the transmission timing based on the created transmission cycle. 2. A fixed-route low-power radio 2 and a communication control means 3 for controlling transmission / reception of the low-power radio 2 are provided on a route bus, and communication with a stop is carried out at a constant cycle. Based on the contents of the communication, in the stop arrival information system that displays the current position of the route bus at the stop or announces the name of the stop on the route bus, the above route bus is issued by another system while waiting for reception. Radio wave reception time counting means 11 for counting the reception time of radio waves,
A transmission cycle creating means 12a for obtaining a transmission cycle by adding the radio wave receiving time obtained by the radio wave receiving time counting means 11 to the base reception waiting time, and performing communication based on the transmission cycle created by the transmission cycle creating means 12a. A stop arrival guide system, wherein the control means 3 determines the transmission timing. 3. The route bus is provided with a specific low power radio 2 and a communication control means 3 for controlling transmission / reception of the specific low power radio 2, and communication is carried out with a stop at a constant cycle, Based on the contents of the communication, in the stop arrival information system that displays the current position of the route bus at the stop or announces the name of the stop on the route bus, the above route bus is issued by another system while waiting for reception. Radio wave reception time counting means 11 for counting the reception time of radio waves,
Transmission cycle creation means 1 for obtaining a transmission cycle by dividing the radio wave reception time obtained by the radio wave reception time counting means 11 by a preset reception rate
2b, and the communication control means 3 determines the transmission timing based on the transmission cycle created by the transmission cycle creation means 12b. 4. The route bus is provided with a specific low power radio 2 and a communication control means 3 for controlling transmission / reception of the specific low power radio 2, and communication is carried out with a stop at a constant cycle, Based on the contents of the communication, in the stop arrival information system that displays the current position of the route bus at the stop or announces the name of the stop on the route bus, the above route bus is issued by another system while waiting for reception. Radio wave reception time counting means 11 for counting the reception time of radio waves,
A transmission cycle creating means 12c for changing the transmission cycle to short or long according to the length of the radio wave receiving time obtained by the radio wave receiving time counting means 11 is provided, and communication is performed based on the transmission cycle created by the transmission cycle creating means 12c. A stop arrival guide system, wherein the control means 3 determines the transmission timing. 5. The route bus is provided with a specific low power radio 2 and a communication control means 3 for controlling transmission / reception of the specific low power radio 2, and communication is carried out with a stop at a constant cycle, Based on the contents of the communication, in the stop arrival information system that displays the current position of the route bus at the stop or announces the name of the stop on the route bus, the above route bus is issued by another system while waiting for reception Radio wave reception time counting means 11 for counting the reception time of radio waves,
The transmission cycle creating means 12d includes a transmission cycle creating means 12d obtained by reading the transmission cycle corresponding to the radio wave receiving time obtained by the radio wave receiving time counting means 11 from the table ROM.
A stop arrival guide system, wherein the communication control means 3 determines the transmission timing based on the transmission cycle created in d.