JPS636699A - Avm system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention is a method of sequentially transmitting a plurality of mobile stations mounted on a plurality of vehicles distributed from a base station to a plurality of areas using a polling method. The present invention relates to a ΔVM system that collects information from each mobile station.

[Technical background of the invention and its problems] In order to monitor multiple vehicles, such as delivery vehicles and taxis, from a central base station, each vehicle is equipped with a mobile station, and each vehicle is monitored from the base station. Various AVM systems have been developed in which a base station collects information about each mobile station by calling a wireless device in a vehicle using a polling method and sending information back from the called mobile station to the base station.

In such an AVM system, in order to efficiently monitor the status of each mobile station, the area to be monitored is divided into multiple areas, different time slots are assigned to each area, and the time slots are used to An AVM system that collects information for each district has been disclosed in, for example, Japanese Patent Application Laid-Open No. 58-21932.

This conventional VM system adopts a method in which the time slot for returning data from mobile stations is variably set depending on the number of mobile stations in each area, or the time slot for returning data is variably set for each time zone. ing. By the way, the number of mobile stations in operation, that is, the number of vehicles in operation, always changes depending on the demand or necessity, depending on the time of day or on a daily basis. In order to collect the latest information, it is necessary to accurately poll the base station according to the number of mobile stations in operation, that is, the number of vehicles dispatched from the base station. If the number of vehicles to be dispatched, that is, the frequency of vehicle dispatch is low, the polling may be low to match the low frequency, but if the frequency of vehicle dispatch is high, the polling cycle must be high.

By the way, in the above-mentioned conventional AVM system, the number of operating vehicles in each area for each time period is set in advance in the timer setting section, and the time slot for return transmission for each time period is varied accordingly. It consists of Although the number of vehicles in operation generally changes significantly depending on the time of day, it does not always change according to the general change, and in some cases, the number of vehicles in operation may increase significantly at different times than usual. be. In such cases, the conventional system described above is unable to perform optimal polling and collect information accurately and without delay, reducing dispatch efficiency and not being able to adequately respond to demand, leading to confusion. There are problems such as inviting

[Purpose of the invention] This invention was made in view of the above, and its purpose is to vary the polling cycle according to the frequency of vehicle dispatch and to accurately collect necessary information even from areas where vehicle dispatch is frequent. The objective is to provide an AVM system that improves vehicle collection and dispatch efficiency.

[Summary of the invention] In order to achieve the above object, an AVM system is provided in which a base station sequentially calls a plurality of mobile stations mounted on a plurality of vehicles dispatched from a base station using a polling method and collects information from each mobile station. As shown in FIG. 1, the present invention includes a frequency calculation means 1 that calculates a vehicle allocation frequency based on the number of times a vehicle is allocated from a base station, and a polling device that varies a polling cycle according to the vehicle allocation frequency. The gist is to have a period variable means 3.

[Embodiments of the invention] Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 2 is a block diagram of a base station device used in an AVM system according to an embodiment of the present invention. The base station device shown in the figure is a device that monitors a mobile station (not shown) consisting of an II device mounted on each of a plurality of vehicles, such as taxis, dispatched from the base station. This base station device has an antenna 11, and uses this antenna 11 to sequentially call a plurality of mobile stations using a polling method, and collects various information from each mobile station, such as current position information of a vehicle. be. The antenna 11 is connected to a transmitter 15 and a receiver 17 via an antenna duplexer 13. The antenna duplexer 13 is a switch for sharing the antenna 11 for transmitting and receiving radio waves. Transmission 11115 transmits a polling signal from this base station to each mobile station, and reception 1ff17 receives a transmission signal from the mobile station. Send R
15 and receiver 17 are connected to a transmission υ control device 21 via a modem 19. Transmission AI control device 21
is for controlling the entire transmission and reception operation of this base station device, and the modem 19 converts the signal from the transmission control device 21 into the signal format of the transmission 11ff15, and also converts the signal from the transmission control device 21 into the signal format of the reception l1ff15.
This is a device that converts the signal from 117 into the signal format of the transmission control device 21. The transmission control device 21 is an input/output (Ilo)
It is connected to the display 25 and the input device 27 via the control device 23 to control the display on the display 25, that is, the display 2
5, and processes input signals from the input device 27, such as vehicle dispatch flow input signals input by a vehicle dispatch operator at the base station.

The transmission control device 21 also includes a polling period control device 2.
9 is connected. This polling period control device 29
is a device that performs a processing flow shown in FIG. 3, which will be described later, to change the polling period from the base station device according to the vehicle allocation frequency. The polling period control device 29 also has an I
/Oa, the input signal from the input device 27 is supplied via the control device 23, but the vehicle dispatched input signal from the input device 27 is used to calculate the vehicle dispatch frequency in the polling periodic control device 29. The number of dispatches from the base station is measured by counting, and the dispatch frequency is calculated from this number of dispatches. Then, the boring period from the base station, that is, the period of information collection inquiries from each vehicle, is determined according to this vehicle allocation frequency, and if the vehicle allocation frequency is high, the boring period is controlled to be high.

The base station device also has a microphone 33 and a speaker 37 with a microphone press switch for voice communication, and these microphones 33 and speakers 37 are connected to the 1ISli! vessel 19
and the receiver 17, and each audio path switch 31.35 is controlled by a transmission control device f121, and can communicate with each mobile station by voice under the control of the transmission control device 21. .

Next, according to the processing flow of FIG. 3 and with reference to FIGS. 4 and 6, the AVM having the base station device of FIG.
The operation of the system, especially the above polling cycle of 1,11WJ
Control in the device 29 will be explained.

In FIG. 3, the polling cycle control device 29 starts the process shown in FIG. 3 when the power is turned on, and first sets initial values necessary for the following process (step 2).
00.210).

The process shown in Figure 3 calculates the dispatch frequency from the number of times vehicles are dispatched from the base station, and calculates the boring period from this dispatch frequency. A variable range setting switch (not shown) is provided so that the size of the cycle can be varied. FIG. 4 is a graph showing the relationship between the dispatch frequency and the boring period by this switch.

In this figure, the horizontal axis shows the vehicle allocation frequency, and the vertical axis shows the boring period.
One of the two dispatch frequency ranges can be selected by the variable range setting switch. In this figure, three boring period curves indicated by symbols a, b, and c are shown for the vehicle dispatch frequency, and the vehicle dispatch frequency ranges H and M are selected by the variable range setting switch.

Boring cycles shown by curves c, b, and a are selected corresponding to L, respectively. As a result, the boring period differs even for the same value of vehicle dispatch frequency depending on which vehicle dispatch frequency range is selected, but this AVM determines which variable range setting switch to select.
This may be done based on the average vehicle allocation frequency in the area where the system is used. Further, in FIG. 4, an example is shown in which three vehicle allocation frequency ranges are set as an example for convenience, but the invention is not limited to this, and it is also easy to set the frequency ranges continuously.

As described above, one of the dispatch frequency ranges H, M, and L is selected in advance by the variable range setting switch, but in the next step 230, the state of the variable range setting switch is input to the input device 27. The detection signal is inputted to the polling frequency WJ control device 29 via the input device 27 to 110 control device 23, and the set dispatch frequency range, M, and H are identified and correspond to this range. Select boring period curves a, b, and c.

Next, in step 230, the number of vehicle allocations is counted, and from this number of vehicle allocations, the vehicle allocation frequency, that is, the number of vehicle allocations per unit time is calculated. The number of dispatched vehicles can be obtained by counting dispatched signals inputted by the operator from the input device 27. Then, by calculating the number of vehicle allocations per unit time, the vehicle allocation frequency is calculated.

Once the vehicle allocation frequency is calculated, the boring period corresponding to this vehicle allocation frequency is determined from the graph shown in FIG. 4 (step 240). In this case, the boring period is determined according to one of the boring period curves a, b, and c set by the variable range setting switch, and this polling period setting value is supplied to the transmission control device 21. Transmission control device 21
performs polling according to this boring cycle. When the processing in step 240 is completed, the process returns to step 220 and the same steps are repeated.

In FIG. 4, the polling period is set to be shortened as the vehicle allocation frequency increases, but this means that information on each mobile station necessary for vehicle allocation is collected in a short time. In addition, if the mobile station is a taxi, etc.,
It is preferable to set a mobile station in an empty vehicle state to have a high priority for data transmission to a base station.

Next, a method of varying the polling cycle, that is, a method of varying the polling cycle according to the vehicle allocation frequency, will be explained with reference to FIG.

Communication between a base station and a mobile station is shown in FIG. 5 (a), for example.
), a time-division time slot is provided, and this time slot is used as the polling slot Pi from the base station.
It is time-divided into a slot S11 for responses from the mobile station and a slot S2i for voice calls, and each slot is sequentially repeated.
That is, Pi.

S1i, S2i; Pi +1.31i +1.3
2i+1:... Each slot is repeated.

Therefore, in order to shorten the polling period in such a time slot configuration, the voice communication slot S2i
, S2i +1. Shorten the duration of... For example, there is a method of shortening this voice call slot to one callable time interval.

Another method, as shown in FIG. 5(b), is to shorten the polling cycle by not normally providing the voice communication slot S2i but providing it only when necessary.

Furthermore, as another method, as shown in FIG. 5(C), mobile station response slots 3i, 3i+1 . There is also a method of shortening the polling cycle by shortening the process such that only empty vehicle information is accepted at an early timing. In this case, the voice call slot is set only when necessary. The lower limit of the polling period shown in FIG. 4 above may be considered to mean that of this method.

[Effect of the invention 1 As explained above, according to the present invention, the vehicle dispatch frequency is calculated and the polling cycle is varied according to this vehicle dispatch frequency, so that the optimum polling cycle can be determined to improve vehicle dispatch efficiency. This allows the necessary information from mobile stations to be collected accurately in a short time, and accurate vehicle allocation can be carried out efficiently and quickly.

[Brief explanation of the drawing]

FIG. 1 is a claim correspondence diagram of the present invention, FIG. 2 is a block diagram of a base station device of an AVM system showing an embodiment of the present invention, and FIG. 3 is a flow rate diagram showing the operation of the device of FIG. 4 and 5 are a graph showing a polling cycle with respect to vehicle allocation frequency and a time slot diagram showing an example of a polling cycle change setting, respectively, for explaining the operation of the apparatus shown in FIG. 2. 1...Frequency calculation means 3...Polling period variable means 29...Polling period control 2 (l device agent Patent attorney Yasuo Miyoshi Figure 1 - Moo Fung: S book ■ play

Claims (1)

[Claims] In an AVM system in which multiple mobile stations mounted on multiple vehicles dispatched from a base station are sequentially called from the base station using a polling method to collect information from each mobile station, the number of dispatches of vehicles dispatched from the base station An AVM system comprising: a frequency calculation means for calculating a vehicle dispatch frequency based on the vehicle dispatch frequency; and a polling cycle variable means for varying a polling cycle according to the vehicle dispatch frequency.