JPH0481240B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to processing data received by a roadside communication device provided in a device that collects route bus passage data and controls route bus operation management.

(Prior art and its problems) The conventional route bus operation management control device has an on-board communication device attached to the route bus, collects route bus passage data from this on-board communication device, and also collects internal route bus passage data. A roadside communication device that transmits the route bus passage data that has been imported into the holding buffer to a central route bus operation management control device, and a route bus operation management based on the route bus passage data transmitted from this roadside communication device. Some buses are equipped with a route bus operation management control device. By the way, in the conventional device, the roadside communication device and the route bus operation management control device are connected by a communication line, so there is an upper limit to the data transmission capacity due to the data transmission speed when using this communication line. There is. Therefore, when route bus passage data that exceeds the data transmission capacity of the communication line is given from the on-board communication device of the route bus to the on-road communication device, the road communication device transmits the given route bus passage data to the route bus operation management control. Since it is not possible to transmit data to the device using a communication line, it is necessary to hold the route bus passage data in a route bus passage data holding buffer while transmission is not possible. However, this route bus passage data holding buffer also has a finite storage capacity, so if route bus passage data that exceeds the holding capacity is given, for example, when the route bus stops at a roadside communication device, There is a problem in that the route bus passage data holding buffer overflows, making it impossible to properly transmit the route bus passage data to the route bus operation management control device. In order to solve this problem, in the prior art, the communication interval between the on-vehicle communication device and the on-road communication device is set to, for example, 6 seconds, thereby making it possible to prevent the overflow of the on-road communication device. However, in such a long communication interval, when the roadside communication device transmits data from the route bus operation management control device to the on-board communication device, the route bus may pass from the roadside communication device during the communication interval. There were times when it became impossible to send the required data.

(Object of the Invention) An object of the present invention is to prevent the above-mentioned overflow of the roadside communication device and to enable communication of necessary data.

(Structure of the Invention) In order to achieve such an object, the present invention provides a roadside communication device that stores route bus passing data collected this time and imported into a route bus passing data retention buffer, and previously collected route bus passage data retention buffer. a comparison means for comparing the route bus passage data stored in the route bus passage data; and a discarding means for discarding the route bus passage data received this time from the route bus passage data holding buffer when the contents of the compared route bus passage data are the same. means. Therefore, according to the present invention, even if the communication line between the on-road communication device and the route bus operation management control device has an upper limit transmission capacity, the communication interval is shortened, and thereby the on-vehicle communication device The on-road communication device can normally transmit data from the route bus operation control device, and can also transmit route bus passage data from the on-board communication device to the route bus operation control device, and is useful for route bus operation management. Traffic management can be controlled normally without any hindrance.

On the other hand, by retaining the received data captured by the on-road communication device for only a predetermined period of time, the problem of the bus being mistakenly recognized as being nearby even though the bus is already far away from the on-road communication device can be avoided.

(Description of Examples) Hereinafter, the present invention will be described in detail based on examples shown in the drawings. In the above claims, the route bus passage data includes data when the route bus passes without stopping in front of the on-road communication device and data when the route bus stops in front of the on-road communication device, and the term “previous time” refers to the previous time. This includes not only the last time, but also the time before last, the time before last, etc. FIG. 1 is an overall block diagram of the route bus operation management control system of this embodiment. In FIG. 1, reference numeral 1 indicates an on-board communication device attached to a route bus 2, and 3, 3, . 6 is a roadside communication device that captures the route bus transit data into the route bus transit data holding buffer and transmits the captured route bus transit data to the central route bus operation management control device 6 via the communication lines 5, 5, . . . This is a route bus operation management control device that controls the operation management of route buses 2 based on route bus passage data transmitted from the route bus passage data.

FIG. 2 is a diagram showing the range of data communication between the on-road communication device 3 installed on the road 7 and the route bus 2. As shown in FIG. In Fig. 2, numerals 2 and 2 are route buses;
Reference numerals 7 and 7 indicate the communication range of the on-road communication device 3, and reference numerals 8 and 8 indicate roadways having upward and downward lanes indicated by arrows 9 and 9. The on-road communication device 3 communicates data with the on-vehicle communication device 1 provided on the route bus 2 that has arrived at the communication range 7, 7.

FIG. 3 is a block diagram of the inside of the roadside communication device 3. As shown in FIG. The on-road communication device 3 includes an antenna 31 for transmitting and receiving data to and from the in-vehicle communication device 1, a modem 32 that modulates and demodulates the contents of the transmission and reception, and collects and imports route bus passing data. Route bus passage data holding buffer 33 that transmits the route bus passage data to the route bus operation management control device 6
The route bus transit data collected this time and imported into the route bus transit data retention buffer 33 and the previous time,
When the comparison means 34 compares the route bus passage data collected two times before and the time before the previous time and is stored in the route bus passage data holding buffer 33, if the contents of the compared two route bus passage data are the same, this time. Discarding means 3 for discarding the received route bus transit data from the route bus transit data holding buffer 33
5, and a transmission means 36 for transmitting the route bus passage data held in the route bus passage data holding buffer 33 to the route bus operation management control device 6.

FIG. 4 is a diagram showing the stored contents of the route bus passage data holding buffer 33. In Fig. 4, A1 is a storage area for the current received data, A2 is a storage area for the latest received data (previously received data), A3 is a storage area for the timer count value after receiving the latest received data, and A4 is the latest previous received data. A5 is a storage area for the timer count value after receiving the most recent previous received data, A6 is a storage area for the latest two previous received data (data received two previous times), A7 is the most recent received data two days before last. A8 is a storage area for the timer count value after receiving the received data, A8 is a storage area for the retention time (set value) of the received data, A9 is a storage area for the transmission data buffer 1 to the route bus operation management control device 6, and A10 is also a storage area for the timer count value after receiving the data. The storage areas A11 . In the example, the storage area for the current received data and the three previous data,
Although the received data of the time before the previous time and that of the received data of the time before the time before the previous time are shown, the present invention is not limited to this.

Next, the operation will be explained with reference to the flowchart shown in FIG. Route bus passage data from the on-vehicle communication device 1 is transmitted to the on-road communication device 3. The on-road communication device 3 takes this route bus passage data into the route bus passage data holding buffer 33 via the antenna 31 and modem 32 as currently received data. This route bus transit data holding buffer 33 has already taken in the received data for three times: the previous time, the time before the previous time, and the time before the time before the previous time. The comparison means 34 sets the currently received data at step n1 in the flowchart of FIG. 5a, and compares the currently received data with the latest received data (previously received data) at step n2. If both received data are the same
Determine YES and proceed to step n6. If they are not the same and the answer is NO, proceed to step n4. In step n4, the current received data is compared with the latest previous received data (received data two times before the previous time), and if both received data are the same, the process advances to step n6. If they are not the same, proceed to step n5. In step n5, the current received data is compared with the most recent data received the day before last (the data received two days before last), and if both received data are the same, the process advances to step n6. If they are not the same, proceed to step n7. In step n7, since the currently received data is not the same as the previously received data, the discarding means 35 discards the most recent received data. Then, the latest previous received data is set to the most recent previous received data, and in step n8, the current received data is set to the latest received data. Furthermore, a timer count value is set in step n9. on the other hand,
At step n6, since the currently received data is not needed, the currently received data is discarded. On the other hand, step
n10 determines whether to transfer the received data to the sending data buffer this time, and if it is transferred,
If NO is determined, it is assumed that the route bus passage data holding buffer 33 is overflowing, otherwise it is determined to be YES and the currently received data is transmitted to the transmission data buffer in step n11. In this way, the received data that has not been discarded is transmitted to the route bus operation management control device 6 via the transmission means 36 as route bus passing data. The route bus passage data retention buffer 33 stores the received data for a certain period of time (for example, 18
seconds), and if this fixed period of time is exceeded, the received data that is held is discarded sequentially. However, the reason why the fixed period of time has passed is that the route bus operation management control device 6 This is to detect the presence of a vehicle. In other words, if the received data is sent to the route bus operation control device after being held in the bus pass holding buffer for a long time, it may be mistakenly recognized as being nearby even though the bus is already far away from the on-road communication device. However, the system discards all received data after a certain period of time to prevent misidentification. If multiple route buses pass within a certain period of time, the communication line between the roadside communication device 3 and the route bus operation management control device 6 may exceed the transmission capacity, but in such a case, the route bus operation management control A queue is created for transmission of transmission data to the device 6, and the reception data is stored in the route bus transit data holding buffer 33 until it is the turn to transmit it. The reason why the fixed time is set to 18 seconds, for example, is that the roadside communication device 3 will not overflow within this time, depending on the performance of the roadside communication device 3. Further, the timing of discarding the received data is determined by the timer count values in the storage areas A3, A5, and A7 of the route bus passage data holding buffer 33 explained in FIG. FIG. 5b is a flowchart for counting up the timer count value of received data. At step s1, an internal timer is counted up from the time the received data is received. In step s2, it is determined whether there is received data that has counted up to a predetermined timer count value, and if so, it is determined as YES and the process proceeds to step s3. In step s3, the received data that has been counted up is discarded.

[Brief explanation of drawings]

The drawings relate to an embodiment of the present invention; Fig. 1 is an overall block diagram of this embodiment, and Fig. 2 explains the data communication range between a roadside communication device installed on the road and a route bus. FIG. 3 is an internal block diagram of the roadside communication device 3, FIG. 4 is a configuration diagram of the storage area of the route bus passage data holding buffer 33, and FIG.
Figures a and b are diagrams for explaining the operation of the embodiment. 1 is a road communication device, 2 is a route bus, 3 is a road communication device, 6 is a route bus operation management control device, 33 is a route bus passage data holding buffer, 34 is a comparison means,
35 is a means of disposal.

Claims (1)

[Claims] 1. An on-road communication device that collects received data from an on-board communication device installed on a route bus, captures the received data into an internal route bus transit data retention buffer, and retains the captured received data for a predetermined period of time, and the on-road communication device The on-road communication device is equipped with a route bus operation management control device that transmits route bus passage data to and from the route bus passage data and performs route bus operation management control. Comparison means for comparing the bus passage data with the previously collected route bus passage data that has been imported into the route bus passage data retention buffer; A received data discarding device for a road communication device, comprising: discarding means for discarding bus transit data from the route bus transit data holding buffer.