JPH05128400A - Road-side communication system using road-side beacon - Google Patents

Abstract

PURPOSE:To reduce the number of vehicle stoppings by the traffic signals as much as possible and to enable smooth driving by sending signals including an information of a parameter of location and color change of a signal set in an advanced direction of vehicle from the road-side beacon. CONSTITUTION:A signal 3 located distance La from the beacon antenna, a signal 4 located distance Lb from the signal 3, a signal 5 located distance Lc from the signal 4, and a signal 6 located distance Ld from the signal 5 are set on the road. A series of signals 3 to 6 set on the road repeats flashing from red to orange through orange to green, that is, cycling with the prescribed offset. Signals including information on the location of the signals 3 to 6 and the parameter of the color change of the signals 3 to 6 are sent from the road- side beacon. The vehicle receives the signals through the processing of which the time zone of flashing the green light can be found, calculating the speed range passing through each signal 3 to 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roadside communication system using a roadside beacon, and more particularly to a vehicle that transmits traffic signal information from a roadside beacon to a vehicle traveling on a road where a traffic signal is installed. The present invention relates to an improved roadside communication system that can be received at.

[0002]

2. Description of the Related Art Various types of navigation devices have been proposed and put into practical use for supporting the running of vehicles on uncharted land. Conventional navigation devices generally
A position detection unit that detects the current position of the vehicle based on the outputs from the distance sensor and the azimuth sensor, a map memory including a CD-ROM, a display device, and the current position of the vehicle detected by the position detection unit. And a control unit for reading a road map including the above from the map memory and displaying it on the display device.

In such a navigation device, the current position of the vehicle on the display device is significantly deviated from the actual position due to an increase in the traveling distance due to the errors that the vehicle speed sensor and the direction sensor necessarily have. There is a risk that Also, if you run near a railroad track,
Magnetic effects can cause large errors in the orientation sensor.

For the purpose of solving such a problem, installation of a roadside beacon has been proposed. The roadside beacon includes beacon antennas arranged at predetermined distances in a road traffic network, and radiates a signal including position data and road direction data from the beacon antenna to a relatively narrow range. A vehicle traveling on the road can receive this signal and capture it in the navigation device to calibrate the vehicle's current position and orientation to the correct one.

Further, not only position data and road direction data but also the following data is added to the signal radiated from the beacon antenna to effectively utilize the roadside beacon. That is, traffic information such as road congestion around the location where the beacon antenna is installed, construction, and other road usage conditions, the location of facilities and houses around the location where the beacon antenna is installed, and the individual name. Additional data such as detailed map information including information about the road, road map information covering a relatively wide range including the location where the beacon antenna is installed, etc. are added to the signal.

[0006]

By the way, in the conventional roadside beacon system, since the information about the color change of the traffic signal installed along the road is not taken in, the traffic signal installed in the traveling direction of the vehicle is not acquired. It was not possible to avoid the stop due to the red lighting. That is, a series of traffic lights installed along the road are set so that the signals switch with a certain time difference, and if the vehicle travels at a certain range of speeds, it will be possible to pass the green light at all green lights. ..

However, when the vehicle travels at a speed outside the above range, it often encounters a red light. Therefore, an object of the present invention is to reduce the number of signal stoppages of a vehicle as much as possible in a roadside communication system that provides information necessary for vehicle position detection and traveling by using a roadside beacon signal, thereby enabling smooth traveling. It is to provide a roadside communication system.

[0008]

According to a first aspect of the present invention, there is provided a roadside communication system using a roadside beacon, wherein the roadside beacon has a position of a traffic light installed in a traveling direction of a vehicle and a color change of the traffic light. The transmission means for transmitting a signal including the information of the parameter of the vehicle is provided, and the vehicle lights up blue of the traffic light based on the information of the position of the traffic light and the parameter of the color change of the traffic light received from the transmission means. An arithmetic means for calculating a speed range that can pass each traffic signal in a time zone and a display means for displaying the speed range calculated by the arithmetic means are provided.

According to a second aspect of the present invention, the structure of the roadside beacon is the same as that of the first aspect of the invention, but the vehicle is provided with information on the position of the traffic signal and the parameter of the color change of the traffic signal received from the transmitting means. On the basis of the above, image data creating means for graphicizing the relationship between the position of the traffic light and the parameter of color change of the traffic light, and display means for displaying the graphic created by the image data creating means are provided.

According to a third aspect of the present invention, the roadside beacon is the same as the first aspect of the invention, but the vehicle is based on the information of the position of the traffic light and the parameter of the color change of the traffic light received from the transmitting means. Calculating means for calculating a speed range in which the vehicle can pass each traffic light during the blue lighting time of the traffic light; and constant speed cruise control means for maintaining the speed of the vehicle within the speed range calculated by the calculating means. Is provided.

A fourth aspect of the present invention is a roadside beacon provided with a transmitting means for transmitting a signal including information on a position of a traffic light installed in a traveling direction of a vehicle and a parameter of a color change of the traffic light.

[0012]

According to the invention of claim 1, from the roadside beacon,
Since the signal containing the information of the position of the traffic signal installed in the traveling direction of the vehicle and the parameter of the color change of the traffic signal is transmitted, the vehicle side should know the blue lighting time zone of the traffic signal based on these received signals. You can Therefore, it is possible to calculate the speed range that can pass through each traffic light and display it on the driver.

According to the second aspect of the present invention, the roadside beacon transmits a signal including information on the position of the traffic signal installed in the traveling direction of the vehicle and the parameter of the color change of the traffic signal. Based on these received signals, the relationship between the position of the traffic light and the parameter of the color change of the traffic light can be visualized. By displaying this figure on the driver, the driver can estimate from the figure how fast the vehicle can travel to pass each traffic light in the blue lighting time zone.

According to the third aspect of the present invention, the road-side beacon transmits a signal including the information of the position of the traffic signal installed in the traveling direction of the vehicle and the parameter of the color change of the traffic signal. Based on these received signals, it is possible to calculate the speed range in which the vehicle can pass each traffic light during the blue lighting time of the traffic light, and the constant speed cruise control means automatically maintains the vehicle speed within this speed range. can do.

According to the invention of claim 4, since the signal containing the information of the position of the traffic light installed in the traveling direction of the vehicle and the parameter of the color change of the traffic light is transmitted, the vehicle receives this signal. By processing, the chance of stopping due to the red lighting of the traffic light can be reduced as much as possible.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 2 is a diagram showing a series of traffic lights installed along a road. As shown in FIG. 2, a beacon antenna 2 that radiates a signal toward the road is installed on the road side of the road. Distance L from the beacon antenna 2 to the road
The traffic signal 3 is installed at a position a, the traffic signal 4 is located at a distance Lb from the traffic signal 3, the traffic signal 5 is located at a position Lc from the traffic signal 4, and the traffic signal 6 is located at a distance Ld from the traffic signal 5.

FIG. 3 is a graph showing the change over time in the color of each traffic light, where the vertical axis represents relative time and the horizontal axis represents the installation position of the traffic light. It is assumed that the traffic light 3 starts one cycle of blue, yellow, and red at time Ta. The time required for this one cycle will be referred to as "cycle". Next traffic light 4
, The cycle starts with a time Tb behind the cycle of the traffic light 3. Further, it is assumed that the traffic light 5 starts a cycle later than the cycle of the traffic light 3 by time Tc, and the traffic light 5 starts a cycle later than the cycle of the traffic light 3 by time Td. These delay times will be referred to as "offsets". Also,
The ratio of the time when the signal is blue to the time when it is red is called "split".

As can be seen from FIG. 3, a series of traffic lights installed on the road repeat the lighting, that is, the cycle of each red, blue, and yellow with a predetermined offset. FIG. 4 is a frame diagram showing a series of information included in the beacon 2 emission signal. The launch signal includes information on the position, cycle, split, and offset of the traffic signal installed on the road along the traveling direction of the vehicle. The emission signal from beacon 2 also contains information indicating the position of the beacon. In order to superimpose the information indicating the position of the beacon, for example, the beacon antenna 2 is used in a different direction.
It is possible to use a technology in which carrier signals composed of individual elements and modulated in anti-phase based on the information of the traffic signal are fed so as to have mutually opposite phases (see Japanese Patent Laid-Open No. 1-92611). ..

The signal radiated from the beacon antenna 2 is received by the receiver mounted on the vehicle running on this road. FIG. 5 is a block diagram showing a configuration example of a receiver of the roadside communication system according to this embodiment. The vehicle-mounted antenna 11 receives the signal radiated from the beacon antenna 2, and the receiver 12 detects and amplifies the signal. The output of the receiver 12 is the position detection device 20.
Given to.

The position detecting device 20 is provided with a data demodulator 21 in addition to a device (not shown) for detecting the position and traveling direction of the vehicle. The data demodulator 21 demodulates the data of the received signal. The signal reception level is as shown in FIG. 6, for example. That is, for the data signal component of the received signal, the received level of the electric field strength distribution centered on the beacon antenna 2 is obtained. On the other hand, for the beacon position signal component, the reception level of the electric field distribution that causes a sharp decrease in level in the main radiation direction boundary line between the in-phase signal and the anti-phase signal can be obtained. Therefore,
In a vehicle traveling on a road, when the reception level of the received beacon position signal component changes and the level drops sharply, it can be determined that the beacon position signal is immediately below the beacon antenna 2. That is, it can be determined that the position of the position data being received has arrived.

The position information of the traffic signal 3, the traffic signal 4, ..., The traffic signal 6 demodulated by the data demodulator 21, the cycle,
Based on the information of split and offset, the processing device 2
2 performs the following processing. That is, as shown in FIG. 1, it is possible to reproduce a graph (the same graph as in FIG. 3) that graphically shows the relationship between the position of the traffic light and the parameter of the color change of the traffic light, and pass the blue signal area of all the traffic lights. Specify such a straight line group. The straight line with the largest slope in this line group represents the minimum speed at which all traffic lights can pass in blue, and the straight line with the least slope represents the maximum speed at which all traffic lights can pass in blue. become.

Considering the current position of the vehicle, FIG.
As shown in, when a straight line group is drawn from the current time T of the vehicle,
The straight line with the largest slope in this group of lines represents the minimum speed at which all traffic lights can pass in blue from the current vehicle position, and the straight line with the smallest slope represents all traffic lights in blue from the current vehicle position. It will represent the maximum speed that can be passed.

The output of the processing device 22 is the output of the display control unit 2.
8 (see FIG. 5) and the display controller 28 controls the display of the display 29. FIG. 8 shows the display control unit 2.
9 is a flowchart showing a display control procedure by 8.
Referring to FIG. 8, display control unit 28 determines whether or not the current position of the vehicle (installation position of the beacon antenna) is detected based on the signal from processing device 22 (step S1).

When the position is detected, it is judged whether or not the position information of the traffic light, the cycle, the split, and the offset information are detected (step S2). When these pieces of information are received, the vehicle side creates a graph as shown in FIG. 1 or FIG. 7 on the basis of these received signals, or performs a numerical calculation corresponding to the creation processing of these graphs, The speed range that can pass each traffic signal is calculated (step S3) and displayed on the driver (step S4). Further, the current position of the vehicle is also displayed (step S5).

FIG. 9 shows a display example of this speed range. Next, a second embodiment will be described. In the second embodiment, the processing device 22 (see FIG. 5) takes in vehicle speed information from a vehicle speed sensor (not shown) mounted on wheels.
Then, instead of displaying the optimum traveling speed as shown in FIG. 9, or together with displaying the optimum traveling speed, the display control device 28 displays the relationship between the position of the traffic light and the parameter of the color change of the traffic light on the screen together with the position of the vehicle. Let The screen that is actually displayed is shown in FIG. According to FIG. 10, the horizontal axis indicates the distance and the vertical axis indicates the time, and the car mark is shown at the current coordinate point of the vehicle.

The car mark moves in the direction of the arrow as the vehicle travels. While looking at this screen, the driver can infer whether or not the next traffic light can be passed within the blue time zone, so that the vehicle speed can be controlled based on this. A vehicle speed sensor (not shown)
If the vehicle speed information cannot be fetched from the display control device 28, the driver cannot move the car mark in FIG. 10, but the driver looks at the current vehicle position and the color condition of each signal on the screen. The optimum speed can be predicted.

Next, a third embodiment will be described. In the third embodiment, the processing device 22 is linked to an in-vehicle auto drive device. The auto-drive device is a well-known system that automatically maintains a constant speed, and if there is a difference between the actual vehicle speed and the optimum speed input from the processing device 22, the opening degree of the throttle valve that adjusts the air flow rate is set. Adjust and control to achieve the optimum vehicle speed. With such a configuration, the optimal vehicle speed can be maintained even if the driver is not particularly aware, and as a result, each traffic signal can be passed in the blue time zone.

[0028]

As described above, according to the first aspect of the present invention, the speed range in which each traffic light can pass in the blue time zone can be calculated and displayed on the driver. If the driver keeps this speed range, the number of times of starting and stopping is reduced, so that the driver can travel with low fuel consumption and the amount of exhaust gas can be reduced. In addition, it can also contribute to extending the life of the vehicle.

According to the second aspect of the present invention, since the relationship between the position of the traffic light and the parameter of the color change of the traffic light is shown, the driver can grasp the running state of the vehicle by visually observing the screen. It is possible to travel at a speed that allows each traffic signal to pass in the blue time zone. According to the third aspect of the present invention, the vehicle speed can be automatically maintained at a speed at which each traffic signal can pass in the blue time zone, so that the driver's labor can be reduced.

According to the invention of claim 4, the roadside beacon transmits a signal including information on the position of the traffic signal installed in the traveling direction of the vehicle and the parameter of the color change of the traffic signal. In this case, by receiving and processing this signal, the chance of stopping the vehicle due to the red lighting of the traffic signal can be reduced as much as possible, which can be useful for reducing fuel consumption and exhaust gas amount.

[Brief description of drawings]

FIG. 1 is a graph showing a relationship between a color change of each traffic light and an optimum traveling speed for passing each traffic light in blue in this embodiment.

FIG. 2 is a diagram showing installation positions of roadside beacons and traffic lights.

FIG. 3 is a graph showing a change in color of a traffic light installed on a road side.

FIG. 4 is a frame diagram of a transmitted signal emitted from a roadside beacon including parameters of traffic light position and traffic light color change.

FIG. 5 is a block diagram of a main part of an in-vehicle receiver.

FIG. 6 is a graph showing a received signal level of an in-vehicle receiver.

FIG. 7 is a graph showing the relationship between the color change of each traffic light and the optimum traveling speed for passing each traffic light in blue.

FIG. 8 is a flowchart showing an outline of a procedure for calculating and displaying an optimum traveling speed.

FIG. 9 is a diagram showing a display example of an optimum traveling speed.

FIG. 10 is a diagram in which the color change of each traffic light and the position of the vehicle for passing each traffic light in blue are displayed on the screen.

[Explanation of symbols]

 20 position detection device 21 data demodulator 22 processing device 28 display control device 30 display device

Claims (4)

[Claims] 1. A roadside communication system using a roadside beacon, wherein the roadside beacon transmits a signal including information on a position of a traffic light installed in a traveling direction of a vehicle and a parameter of a color change of the traffic light. The vehicle can pass each traffic signal in the blue lighting time zone of the traffic signal based on the information of the position of the traffic signal and the parameter of the color change of the traffic signal received from the transmission means. A roadside communication system using, comprising: a calculating means for calculating a speed range and a displaying means for displaying the speed range calculated by the calculating means. 2. A roadside communication system using a roadside beacon, for transmitting to the roadside beacon a signal including information on a position of a traffic light installed in a traveling direction of a vehicle and a parameter of a color change of the traffic light. Image data for graphically representing the relationship between the position of the traffic light and the color change of the traffic light based on the information of the position of the traffic light and the parameter of the color change of the traffic light received from the transmission means. A roadside communication system using, comprising: a creating means and a display means for displaying a graphic created by the image data creating means. 3. A roadside communication system using a roadside beacon, for transmitting to the roadside beacon a signal including information on a position of a traffic signal installed in a traveling direction of a vehicle and a parameter of a color change of the traffic signal. The vehicle can pass each traffic signal in the blue lighting time zone of the traffic signal based on the information of the position of the traffic signal and the parameter of the color change of the traffic signal received from the transmission means. A roadside communication system using, comprising: a calculation means for calculating a speed range and a constant speed cruise control means for maintaining the speed of a vehicle within the speed range calculated by the calculation means. 4. A roadside beacon, comprising: a transmitting means for transmitting a signal including information on a position of a traffic light installed in a traveling direction of a vehicle and a parameter of a color change of the traffic light.