JP7079144B2 - Information processing device and traffic signal control device - Google Patents

Description

The present invention relates to an information processing device and a traffic signal control device that write and read data signals via a dual port RAM.

The traffic signal controller receives a control command from a central device installed in a traffic control center, etc., and has a function to control the number of seconds of light color based on the command, and information on the controller (result of control based on the command). Etc.) have the function of transmitting to the central device. These functions include a main control unit that controls the number of seconds of the light color and a transmission unit that communicates with the central device. In a traffic signal controller, a dual port RAM is generally used for exchanging information (data signal) between two CPUs (see Patent Document 1).

The passing of data signals via the dual port RAM is performed according to a predetermined handshake procedure. In the handshake procedure, typically, when the writing of data from one CPU is completed, the set flag is turned ON, and the other CPU that has confirmed the state starts reading the data. When the reading of data is completed, the read flag is turned on, and when one CPU confirms the state, the set flag is turned off. When the other CPU confirms the OFF state of the set flag, the read flag is turned OFF. By writing or reading the data after confirming the states of the set flag and the read flag in this way, the data can be reliably exchanged between the two CPUs.

As a prior art of this type, for example, Patent Document 2 comprises a first device that periodically accesses the dual port RAM and a second device that periodically accesses the dual port RAM. After the dual-port RAM is accessed, the device outputs an accessible signal with a predetermined time width, and the second device is configured to access the dual-port RAM in synchronization with the period of the accessible signal. The method is disclosed.

Japanese Unexamined Patent Publication No. 8-124093 Japanese Unexamined Patent Publication No. 9-44395

In the traffic signal controller, the data writing process and the data reading process to the dual port RAM are typically performed at a fixed operation cycle. Therefore, if these timings are the same or if the timings fluctuate, there is a problem that the handshake fails and the processing time is extended to the next operation cycle. On the other hand, the method of executing the handshake while arbitrating between two devices (CPUs) as described in Patent Document 2 has a problem that the configuration becomes complicated because a separate process for arbitration is required. There is.

In particular, in recent years, the development of a driving support system (ITS: Intelligent Transport System) that provides traffic parameters useful for safe driving support and eco-driving support using probe data has been promoted. In this system, the light color information of the traffic light installed on the route is transmitted from the roadside antenna to the on-board unit, and it is possible to provide the driver with appropriate speed and information according to the traffic condition and the driving scene. On the other hand, the delay of the handshake procedure as described above may cause a deviation in the time information of the light color transmitted from the signal controller to the roadside antenna, so that the light color information that changes from moment to moment is used. It becomes difficult to provide it stably at an appropriate timing.

In view of the above circumstances, an object of the present invention is to provide an information processing device and a traffic signal control device capable of shortening the processing time required for passing data signals with a simple configuration.

In order to achieve the above object, the information processing apparatus according to one embodiment of the present invention includes a dual port RAM, a main control unit, and a transmission unit.
The dual port RAM is configured so that data signals are written and read in a predetermined cycle.
The main control unit is configured to write a first data signal to the dual port RAM in a first cycle.
The transmission unit is configured to read the first data signal from the dual port RAM in a second cycle different from the first cycle.

According to the above information processing device, since the first cycle and the second cycle are different from each other, it is possible to avoid the situation where the operation timing of the main control unit and the operation timing of the transmission unit are the same as much as possible to shorten the processing time. Can be planned. Even if the handshake fails, the data signal can be reliably written or read at the next operation timing.

The second cycle may be set shorter than the first cycle.
As a result, the time required for reading the data signal can be shortened.

The second cycle is set to, for example, ½ of the length of the first cycle.

The transmission unit writes a second data signal to the dual port RAM in a third cycle longer than the first cycle, and the main control unit writes the second data signal from the dual port RAM in the third cycle. It may be configured to read the data signal of 2.

The traffic signal control device according to one embodiment of the present invention includes a dual port RAM, a main control unit, and a transmission unit.
The dual port RAM is configured to write and read a data signal related to a signal lamp in a predetermined cycle.
The main control unit is configured to write the data signal to the dual port RAM in the first cycle.
The transmission unit is configured to read the data signal from the dual port RAM in a second cycle different from the first cycle and transmit it to the roadside antenna.

As described above, according to the present invention, it is possible to shorten the processing time required for passing data signals with a simple configuration.

It is a schematic block diagram of the traffic signal system which concerns on one Embodiment of this invention. It is a functional block diagram which shows the structure of the signal control device in the said traffic signal system. It is explanatory drawing which shows the typical structure and operation of DP-RAM. It is explanatory drawing which shows the typical structure and operation of DP-RAM. It is a conceptual diagram explaining the fluctuation of the processing time required for a handshake procedure. It is a figure which shows an example of the handshake procedure in the said signal control device. It is a figure explaining one operation of the said signal control device. It is a figure which shows the detail of DP-RAM in the said signal control apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Traffic signal system]
FIG. 1 is a schematic configuration diagram of a traffic signal system 100 according to an embodiment of the present invention.

The traffic signal system 100 of the present embodiment includes a traffic signal control device 10 and a roadside antenna 20.

The traffic signal control device 10 uses a commercial power source as a power source to control light emission (blue, yellow, red) of the lamp 1 of the traffic light S at a preset lighting time (displayed seconds) and cycle. The traffic signal control device 10 is typically installed in a control box (not shown) attached to a support column that supports the lamp 1. The traffic signal control device 10 is configured to be able to transmit signal information about the lamp 1 to the roadside antenna 20. The traffic signal control device 10 is configured to be communicable with a traffic control center (not shown), but is not limited to this.

The roadside antenna 20 is configured to be able to communicate with the vehicle V traveling on the road (or route) R on which the traffic light S is installed, and can transmit the signal information transmitted from the traffic signal control device 10 to the vehicle V. It is composed. Although not shown in the vehicle V, in addition to an in-vehicle device that can receive signal information transmitted from the roadside antenna 20, a device (display, display, that presents information related to the lamp 1 to the driver based on the signal information. Speakers, etc.) are installed.

The signal information is information related to the light color of the traffic light 1 located in front of the traveling direction of the vehicle V, and typically includes information related to the light color of the traffic light 1 when the vehicle V passes. This makes it possible to provide driving support information such as signal passage support and red light deceleration support to the traveling vehicle V.

The traffic signal system 100 may further include a detector 30 capable of detecting other vehicles or pedestrians on the road R or a road intersecting the road R and transmitting the detection signal to the roadside antenna 20. .. In this case, the roadside antenna 20 transmits not only the signal information but also the warning information for notifying the approach of another vehicle or pedestrian to the vehicle V based on the information transmitted from the sensor 30. May be configured to be possible.

Next, the details of the traffic signal control device 10 will be described.

[Signal control device]
FIG. 2 is a functional block diagram showing the configuration of the traffic signal control device 10. The traffic signal control device 10 includes information processing including a main control unit 11 (main control unit), a transmission unit 12 (transmission unit), and a dual port RAM (Random Access Memory) 13 (hereinafter, also referred to as DP-RAM 13). It is configured as a device.

The main control unit 11 has a control unit 111, a signal generation unit 112, a clock 113, and a memory 114. The control unit 111 is composed of an arithmetic unit such as a CPU (Central Processing Unit), and controls each unit of the main control unit 11 in an integrated manner.

The control unit 111 controls lighting and switching of the lamp 1 in synchronization with the time information acquired by the clock 113 based on the control setting information stored in the memory 114. The control setting information typically refers to a constant of the traffic light S (hereinafter, also referred to as a traffic light constant). Traffic light constants include ladder tables, cycles, splits, offsets, timed tables, sensitive seconds, and so on. The memory 114 further stores a control program, control parameters, and the like that cause the control unit 111 to execute a predetermined operation. Instead of the clock 113, a GPS (Global Positioning System), a radio clock, or the like may be adopted.

The signal generation unit 112 generates a light emission control command of the lamp 1 and signal information about the lamp 1 provided to the roadside antenna 20 based on the command of the control unit 111. The lamp 1 causes each lamp to emit light based on the control information output from the signal generation unit 112.

The signal information provided to the roadside antenna 20 typically includes a data signal relating to the light color of the lamp 1 after a predetermined second. The data signal includes, for example, time information and the remaining time until the light color at that time is switched to another color. The signal generation unit 112 is configured to be able to generate or update signal information at a predetermined time cycle and write the information to the DP-RAM 13.

The transmission unit 12 has a control unit 121, a communication unit 122, a clock 123, and a memory 124. The control unit 121 is composed of an arithmetic unit such as a CPU (Central Processing Unit), and controls each unit of the transmission unit 12 in an integrated manner.

The control unit 121 is configured to be able to read the signal information written in the DP-RAM 13 from the main control unit 11 in a predetermined time cycle in synchronization with the time information acquired by the clock 123.

The communication unit 122 includes a communication module configured to be able to communicate with the traffic control center and the roadside antenna 20. The communication unit 122 is configured to be able to transmit the signal information (first data signal) read from the DP-RAM 13 to the roadside antenna 20. Further, as will be described later, the communication unit 122 is configured to be able to transmit the information (second data signal) transmitted from the traffic control center to the main control unit 11 via the DP-RAM 13. The communication method between the communication unit 122 and the traffic control center and the roadside antenna 20 is not particularly limited, and may be wireless or wired.

The memory 124 stores a control program, control parameters, and the like that cause the control unit 121 to execute a predetermined operation. Instead of the clock 123, a GPS, a radio clock, or the like may be adopted.

The DP-RAM 13 is a storage device capable of writing signal information (data signal) from the main control unit 11 and reading the signal information from the transmission unit 12 at predetermined operation cycles, respectively. .. The DP-RAM 13 has a function of relaying the transfer of signal information between the main control unit 11 and the transmission unit 12 according to the handshake procedure described later. Although the DP-RAM 13 is configured independently of the main control unit 11 and the transmission unit 12, it may be mounted in common on the board on the main control unit 11 side or the board on the transmission unit 12 side.

3 and 4 are explanatory views showing a typical configuration and operation of the DP-RAM. The handshake procedure is not limited to this, and other procedures may be adopted.

As shown in FIGS. 3 and 4, the handshake procedure is started by writing data from the main control unit (time T1). When the data writing is completed, the DP-RAM set flag is turned ON (procedure 1). The transmission unit that has confirmed the ON state of the set flag starts reading the data (time T2), and when the data reading is completed (time T3), the read flag of the DP-RAM is turned ON (procedure 2). When the main control unit confirms the ON state of the read flag, the set flag is turned OFF (time T4, procedure 3). When the transmission unit confirms the OFF state of the set flag, the read flag is turned OFF and a series of handshake procedures is completed (time T5, procedure 4). By writing or reading the data after confirming the states of the set flag and the read flag in this way, the data can be reliably transferred between the two devices (main control unit and transmission unit).

Here, since the main control unit and the transmission unit each operate based on their own timing means (clocks 113 and 123) and do not have a mechanism for coordinating or arbitrating each operation, each of them. Data writing or reading processing may be vacant due to overlapping operations (timing collision). The same phenomenon can occur when a temporal fluctuation occurs in either one of the operation cycles or the operation timing. Therefore, when the operation cycles of the main control unit and the transmission unit for the DP-RAM are the same, the time required from the start to the end of the handshake procedure may fluctuate at most about twice the operation cycle (FIG. 5). reference).

For example, as shown in FIG. 5A, when the procedure 2 is executed immediately after the procedure 1 and the procedure 4 is executed immediately after the procedure 3, the processing time required for the series of handshake procedures is the shortest of about 20 ms. Is. On the other hand, as shown in FIG. 5B, when the processing cycle fluctuates and the processing is vacant on the writing side and the reading side (the figure shows an example in which steps 3 and 4 have failed once), the processing time is The maximum is about 60 ms. In this case, the processing time fluctuates by about 40 ms.

In the traffic signal system applied to this embodiment, the light color information of the traffic light installed on the route is transmitted from the roadside antenna to the on-board unit, and the appropriate speed and information according to the traffic situation and the driving scene are provided to the driver. It is possible to do. On the other hand, the delay of the handshake procedure as described above may cause a deviation in the time information of the light color transmitted from the signal control device to the roadside antenna, so that the light color information that changes from moment to moment is used. It becomes difficult to provide it stably at an appropriate timing.

Therefore, in the present embodiment, the write operation cycle of the data signal of the main control unit 11 to the DP-RAM 13 (first cycle) and the read operation cycle of the data signal of the transmission unit 12 to the DP-RAM (second cycle). And are set to different cycles. By making the operation cycle different in this way, even if the operation cycle fluctuates, it is possible to prevent the processing on the writing side or the reading side from becoming empty as much as possible, and even if the processing becomes empty. However, the fluctuation width of the processing time of the handshake procedure can be reduced as compared with the case where the operation cycles are the same.

FIG. 6 is a diagram showing an example of a handshake procedure in the traffic signal control device 10 of the present embodiment. As shown in the figure, in the present embodiment, the data signal reading operation cycle of the transmission unit 12 is set to be shorter than the data signal writing operation cycle of the main control unit 11. As a result, the fluctuation width of the processing time required for the handshake procedure can be effectively reduced. Further, as the reading operation cycle of the transmission unit 12 is made smaller, the fluctuation width becomes smaller, and the time required for the handshake procedure can be treated as substantially constant.

The read operation cycle is not particularly limited, and may be, for example, 1/2, 1/3, 1/4, 1/5, or less than the write operation cycle. The difference between the write operation cycle and the read operation cycle is set longer than the time for the main control unit 11 to write the data signal to the DP-RAM 13. As a result, it is possible to effectively suppress the collision between the writing operation and the reading operation of the data signal.

The write operation cycle and the read operation cycle correspond to a predetermined count number of time information acquired from the clocks 113 and 123. By adjusting the number of counts set in the control units 111 and 121, the write operation cycle and the read operation cycle can be arbitrarily set.

In the present embodiment, when the write side by the main control unit 11 is 20 ms, the read operation cycle by the transmission unit 12 is set to 10 ms. In this way, by setting the read operation cycle to half (1/2) of the write operation cycle, the processing on the write side is not vacant, and the procedure 2 is executed between the procedure 1 and the procedure 3. The fluctuation width of the processing time of the handshake procedure can be effectively reduced.

For example, as shown in FIG. 7A, when the procedure 2 is executed immediately after the procedure 1 and the procedure 4 is executed immediately after the procedure 3, the operation cycles of the write side and the read side are the same. Similarly, the shortest processing time required for a series of handshake procedures is about 20 ms. On the other hand, as shown in FIG. 7B, when the processing cycle fluctuates and the processing becomes empty on the reading side (an example in which step 4 fails is shown in the figure), the processing time becomes a maximum of about 30 ms, and the processing becomes possible. The fluctuation width of time can be reduced to about 10 ms.

As described above, according to the present embodiment, the time required for passing the data signal between the main control unit 11 and the transmission unit 12 (time required for the handshake procedure) can be minimized, so that the traffic signal can be minimized. Signal information that changes from moment to moment can be stably transmitted from the control device 10 to the roadside antenna 20 without delay. As a result, it is possible to avoid a time lag in the signal information provided from the roadside antenna 20 to the vehicle V as much as possible, so that the desired driving support control can be performed in each vehicle V. Further, since coordination or arbitration between the two units 11 and 12 is not required, the configuration of the traffic control device 10 can be simplified.

[Other configurations]
FIG. 8 is an explanatory diagram showing the details of the DP-RAM 13. The DP-RAM 13 has a first memory area 13A capable of passing a first data signal from the main control unit 11 side to the transmission unit 12 side, and a second memory area 13A from the transmission unit 12 side to the main control unit 11 side. It has a second memory area 13B capable of passing a data signal.

The first data signal corresponds to the signal information regarding the traffic light 1 transmitted from the traffic signal control device 10 to the roadside antenna 20. In the first memory area 13A, as in the first embodiment, the main control unit 11 writes the first data signal in the first operation cycle, and the transmission unit 12 writes the first data signal in the first operation cycle. The first data signal is read in the second cycle of half the length.

The second data signal corresponds to, for example, various information (for example, control setting information) transmitted from the traffic control center to the traffic signal control device 10, and corresponds to, for example, a traffic condition (traffic volume, degree of congestion, etc.). It is sent from the traffic control center when changing the signal constant.

In the second memory area 13B, information (second data signal) is transferred from the transmission unit 12 to the main control unit 11 according to a predetermined handshake procedure. Since such information is less susceptible to the transmission time lag than the first data signal, data is written and read in a third operation cycle longer than the first operation cycle. That is, the third operation cycle is set to a cycle having an appropriate length of 20 ms or more, for example, a cycle having a length of 30 ms, 50 ms, or 100 ms or more.

The main control unit 11 stores (updates) the second data signal received via the transmission unit 12 and the DP-RAM 13 in the memory 114 (see FIG. 2), and stores (updates) the second data signal with respect to the lamp 1 based on the new control setting information. A light emission control command and signal information regarding the lamp 1 provided to the roadside antenna 20 are generated.

According to the present embodiment, one DP-RAM 13 transfers a first data signal from the main control unit 11 to the transmission unit 12, and transfers a second data signal from the transmission unit 12 to the main control unit 11. Therefore, the number of parts does not increase, and therefore the configuration of the traffic signal control device 10 can be simplified.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made.

For example, in the above embodiments, the data signal writing operation cycle by the main control unit 11 and the data signal reading operating frequency by the transmission unit 12 are fixed, but these operating frequencies may be dynamically changed. For example, when it is detected that there is an empty process in a series of handshake procedures, the operation cycle can be reset to a different period to further reduce the empty process.

Further, in the above embodiment, the data signal reading operation cycle of the transmission unit 12 is set to be shorter than the data signal writing operation cycle of the main control unit 11, but instead of this, the reading operation cycle is described above. The write operation cycle may be set shorter. This also makes it possible to obtain the same action and effect as described above.

Further, in the above embodiment, the traffic signal control device has been described as an example, but the present invention is not limited to this, and the present invention is widely applicable to an information processing device including a DP-RAM that transfers a data signal between two devices. ..

1 ... Lamp 10 ... Traffic signal control device 11 ... Main control unit 12 ... Transmission unit 13 ... DP-RAM
20 ... Roadside antenna 30 ... Sensor 100 ... Traffic signal system 111, 121 ... Control unit 112 ... Signal generation unit 113, 123 ... Clock 122 ... Communication unit 114, 124 ... Memory

Claims (4)

A dual-port RAM in which data signals are written and read in a predetermined cycle,
The main control unit that writes the first data signal to the dual port RAM in the first cycle,
It is provided with a transmission unit that reads the first data signal from the dual port RAM in a second cycle different from the first cycle.
The transmission unit writes a second data signal to the dual port RAM in a third cycle longer than the first cycle.
The main control unit reads the second data signal from the dual port RAM in the third cycle.
Information processing equipment. The information processing apparatus according to claim 1.
The information processing apparatus in which the second cycle is set shorter than the first cycle. The information processing apparatus according to claim 2.
The information processing apparatus whose second cycle is set to half the length of the first cycle. A dual-port RAM in which data signals related to signal lamps are written and read in a predetermined cycle.
A main control unit that writes the data signal to the dual port RAM in the first cycle,
It is provided with a transmission unit that reads the data signal from the dual port RAM in a second cycle different from the first cycle and transmits the data signal to the roadside antenna.
The transmission unit writes a second data signal to the dual port RAM in a third cycle longer than the first cycle.
The main control unit reads the second data signal from the dual port RAM in the third cycle.
Traffic signal control device.

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