JP2004252718A - Red traffic signal stop system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To support a driver to recognize that a traffic signal at an intersection turns red with a high probability . <P>SOLUTION: Roadside equipment 5 is prepared in a signal 3 of an intersection 2, and information of a red signal is transmitted to a communication area 6. In-vehicle equipment 7 is mounted on an automobile 1, the information of red signal is received from the roadside equipment 5, and it is informed by an information means then a driver is urged. Even if the driver passes over the red signal by mistake, it can be noticed by an informing operation. It is informed by sound at first, and next, by braking lightly so as to feel that. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a red light stop system that assists a driver stopping a vehicle at a stop position when a traffic light installed on a road is in a red light state.
[0002]
[Prior art]
In driving a car, one of the major factors that reduces the occurrence of traffic accidents is that individual drivers drive according to traffic lights provided at intersections. However, when driving at a constant speed, when the lighting state of the signal changes from a green light to a yellow light, or to a red light, etc. They tend to make unreasonable approaches.
[0003]
The driver must make such a situation judgment while actually watching the lighting condition of the traffic light.When the driver changes the situation, the driver must force a sudden stop based on the driving conditions at that time or the road ahead. In some cases, objective judgment cannot be made.
[0004]
Furthermore, even when the driver is ill or distracted, such as when he is distracted by something, it takes time to recognize the situation at the point where the lighting state of the signal changes. In some cases, it may not be possible to make a stop determination immediately. Even in such a case, there is a risk that the vehicle will collide with a vehicle traveling ahead, or that the vehicle will enter an intersection in a dangerous state at a traffic light change.
[0005]
Conventionally, in the relationship between a traffic light and a car, when a vehicle running in platoon passes through an intersection with a traffic light, the lighting state of the traffic light is maintained at a green light until all vehicles pass. For example, there is one in which a lighting state of a traffic light is controlled so that the vehicle does not stop at a red light when traveling (see, for example, Patent Document 2).
[0006]
[Patent Document 1]
JP 2000-331282 A
[Patent Document 2]
JP 2000-222680 A
[Problems to be solved by the invention]
However, the prior art as described above does not solve the above-described problem, but is merely a technique that is implemented in the relationship between a traffic light and an automobile. The technology disclosed in the above-mentioned patent document is configured to control the lighting state of a traffic light, so that a vehicle of interest can run smoothly by controlling the lighting of the traffic light. When such a technology is applied to a traffic signal at an intersection or the like, there are the following problems.
[0009]
That is, at an intersection with a large traffic volume, it is impossible to perform signal control to achieve the same condition for all of the many vehicles approaching from all sides. Prioritizing one vehicle would yield the other vehicle, resulting in inequity. Such control is effective when the state of occurrence of traffic congestion or the like is totally eliminated, but the point of determination is difficult.
[0010]
The present invention has been made in view of the above circumstances, and its purpose is to change the lighting time of a traffic light and the like without changing the control according to the traffic situation of the vehicle, and at the intersection of the intersection and the like under a predetermined lighting control. A driver traveling at a traffic light installation location can recognize the lighting state of the traffic light and its change with a high probability, so that the driver can more reliably determine the traffic situation. It is to provide a red light stop system.
[0011]
[Means for Solving the Problems]
According to the first aspect of the present invention, since the roadside device attached to the traffic light transmits a signal indicating at least a red light state among the lighting states of the traffic light, the intersection at which the vehicle has the traffic light is provided. When the vehicle approaches, the on-vehicle device of the vehicle receives a signal related to the lighting state of the traffic light from the roadside device, and when receiving the signal indicating the lighting state of the red light, performs a notification operation for prompting a stop by the notification unit.
[0012]
Thus, even if the driver of the vehicle is inadvertently overlooking that the traffic light is a red light, the alerting means alerts the driver, so that the operation of stopping the vehicle can be performed without delay. As a result, it can be assisted to avoid a situation where the vehicle goes beyond a stop line such as an intersection at a red light.
[0013]
According to the second aspect of the present invention, in the above invention, when a notification operation is performed by the notification means while the vehicle is traveling in the communication area of the roadside device at a legal speed, the driver starts the braking operation. If the driver notices that the signal is a red light, the braking operation for stopping is started from that point, so if the driver notices that it is a red light, You will be able to stop just before the intersection.
[0014]
According to the third aspect of the present invention, in the second aspect of the present invention, the communication between the roadside device and the on-vehicle device uses the DSRC communication system. In addition to the setting, it is possible to reliably receive the signal from the roadside device within the communication area.
[0015]
According to the fourth aspect of the present invention, in each of the above-mentioned inventions, the in-vehicle unit notifies the vehicle on the condition that the traveling state of the vehicle does not tend to decelerate when the signal indicating the lighting state of the red signal of the traffic signal is received. When the driver visually notices the lighting state of the red light and starts the braking operation for deceleration, the driver inadvertently notifies that the signal is a red light. Therefore, the notification operation can be performed only when necessary without deceleration, and the driver can be properly assisted.
[0016]
According to the fifth aspect of the present invention, in each of the above-mentioned inventions, if the vehicle does not shift to the deceleration tendency after performing the informing operation of the in-vehicle device by the informing means, the braking control is performed to such an extent that the driver can feel it. When the driver does not shift to the braking control in response to the red signal notification operation due to the driver's reduced attention and the like, the braking control is small enough to be felt by the body. , The driver can be alerted to the driver while driving, and can be assisted to perform the stop braking operation.
[0017]
According to the invention of claim 6, in the invention of claim 5, the in-vehicle device is configured not to execute the braking control when the vehicle tends to accelerate after performing the notification operation by the notification unit. Therefore, for example, by judging a situation in which the driver is performing the acceleration control after recognizing the red signal, it is possible to prevent the driving state from being disturbed due to the careless braking control.
[0018]
According to the invention of claim 7, in each of the above-mentioned inventions, the roadside device transmits a vehicle inspection information request signal requesting the vehicle-mounted device to transmit information on the length of the vehicle, and a response from the vehicle-mounted device is transmitted. A stop map is created based on the signal to determine whether vehicles existing in the communication area can be stopped without colliding, so if many vehicles are approaching the signal location However, the state at the time of stopping can be grasped in consideration of the length of those vehicles.
[0019]
According to the invention of claim 8, in the invention of claim 7, the vehicle-mounted device responds to the vehicle inspection information request signal transmitted from the roadside device when it is first received in the communication area. With this configuration, if the vehicle inspection information is transmitted for the first time during the communication several times, no time is required for the transmission thereafter, so that quick and accurate communication can be performed.
[0020]
According to the ninth aspect of the present invention, in each of the above-mentioned inventions, when the vehicle-mounted device receives a signal indicating the lighting state of the red signal of the traffic light from the roadside device, the relationship between the distance from the received position to the stop position and the speed is obtained. Is detected and a deceleration map for stopping at the position where the vehicle should be stopped is created, so after the driver recognizes the red light and starts the braking operation for stopping, how much braking can be performed For example, it is possible to recognize whether the vehicle can be stopped at the position where the vehicle should be stopped, and it is possible to perform smooth stop control.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
Hereinafter, a first embodiment in which the present invention is applied to a traffic light at an intersection will be described with reference to FIGS.
FIG. 2 shows a schematic configuration of the present system. When a vehicle 1 as a vehicle approaches an intersection 2, a communication with a traffic light 3 disposed at the intersection 2 is performed. Is shown.
[0022]
The traffic lights 3 are provided like the traffic lights 3a to 3d with respect to the automobile 1 traveling on each of the roads 4a to 4d connected to the intersection 2. These traffic lights 3a to 3d are provided so as to indicate whether or not the traffic at the intersection 2 is possible when the automobile 1 traveling on each of the roads 4a to 4d heads for the intersection 2.
[0023]
In addition, the pillars on which the traffic lights 3d and 3c are installed are provided with traffic lights 3aa and 3bb provided so as to be displayed immediately before the intersection 2 with respect to the automobile 1 traveling on the roads 4a and 4b, respectively. The traffic lights 3aa and 3bb are provided with a roadside device 5 according to the present invention. The roadside device 5 is configured to set a communication area 6 before the intersection 2 and to communicate with an onboard device 7 (see FIG. 1) mounted on the automobile 1 as described later.
[0024]
The roadside device 5 and the on-vehicle device 7 are configured to perform communication by a Dedicated Short-Range Communication (DSRC) method (narrow area communication method). The communication area 6 is set such that communication is possible within a range of a distance Lm in front of the intersection 2 with the stop line of the intersection 2 as a base point. The distance L is a predetermined distance that is equal to or longer than a distance at which the traffic light 3a or 3aa can stop at a stop line when the lighting state of the traffic light 3a or 3aa changes to a red light when the vehicle 1 is traveling at a legal speed, for example.
[0025]
Next, an electrical configuration of the roadside device 5 and the on-vehicle device 7 will be described with reference to FIG. The roadside device 5 is mainly configured by the control device 8, and also serves as a control device for controlling lighting of the traffic light 3aa (or 3bb). The control device 8 stores a signal information transmission program described below, and transmits red signal lighting information to the on-vehicle device 7 of the vehicle 1 that has entered the communication area 6. The transmission of the signal is performed by the DSRC communication device 9 via the antenna 9a and the signal from the vehicle-mounted device 7 is received.
[0026]
The on-vehicle device 7 is mainly configured by the control circuit 10. The control circuit 10 includes a CPU, a ROM, a RAM, and the like, and stores a control program to be described later, and controls the driver to perform a notification operation based on a signal received from the roadside device 5. The DSRC communication device 11 inputs a signal received by the antenna 11a to the control circuit 10. The alarm device 12 as a notification means performs a notification operation for notifying the driver of signal information, and mainly performs a notification operation by sound. The brake control system 13 controls the drive of the brake mechanism 14 to slightly apply a brake, thereby transmitting signal information to the driver. A car navigation device 15 is connected as necessary as a means for transmitting traffic light information.
[0027]
Next, the operation of the present embodiment will be described with reference to FIGS.
In the present system, the roadside device 5 executes the program shown in FIG. 4 and transmits signal information to be described later in the communication area 6 at regular time intervals. When the cars 1a and 1b approaching the intersection 2 enter the communication area 6, the signal information can be received. First, the control device 8 of the roadside device 5 sets a color signal, a transmission time, and a stop distance as information to be transmitted to the vehicle-mounted device according to the program shown in FIG. A request signal is set (step S1).
[0028]
The control device 8 transmits the set signal from the DSRC communication device 9 to the communication area 6 via the antenna 9a (Step S2). Thereafter, it waits for a response signal from the on-vehicle device 7 that has entered the communication area 6 (step S3). If “NO”, the process returns to step S1 to repeat the above processing. If “YES”, the control device 8 receives the transmission time information, the total length information, and the registration number information transmitted from the vehicle-mounted device 7 (step S4), and returns to step S1.
[0029]
On the other hand, in the vehicle-mounted device 7, the control circuit 10 performs communication processing according to the program shown in FIG. When the control circuit 10 of the on-vehicle device 7 starts the program, it enters a standby state of waiting for a signal to be received (Step T1 is repeatedly performed). When a signal is transmitted from the roadside device 5 and the signal is received from the antenna 11a via the DSRC communication device 11, when the vehicle approaches the intersection 2 and enters the communication area 6 of the roadside device 5, or The control circuit 10 determines “YES” in step T1 and confirms the stopping distance at this time (step T2).
[0030]
Thereafter, the control circuit 10 determines whether or not the received signal is the first time (step T3), and if "YES", prepares to transmit the information of the reception time (step T4), and transmits the signal to the DSRC communication. The transmission is performed by the device 11 to the roadside device 5 via the communication area 6 (step T5).
[0031]
When the transmission is completed (determined as “YES” in step T5), the control circuit 10 starts the arithmetic processing of the stop system. Here, the control circuit 10 first calculates the current vehicle speed (step T6), and obtains a deceleration map from the vehicle speed and distance information to the stop line (step T7). The deceleration map is set in advance from the relationship between the vehicle speed and the stopping distance, and the corresponding map is read and set.
[0032]
Next, the control circuit 10 determines whether or not the vehicle 1a on which the in-vehicle device 7 is mounted is currently decelerating (step T8). This is for determining whether or not the vehicle is in a deceleration state by looking at a change in speed, for example, when the lighting state of the traffic lights 3a and 3aa has changed to a red light, and the driver recognizes this and applies a brake. If there is a tendency to slow down. Further, when the driver is inadvertent and does not notice the red light, it is assumed that the driver does not apply the brake.
[0033]
If the control circuit 10 determines that the vehicle is decelerating, the control circuit 10 determines “YES” in step T8 and returns to step T1 to repeat the above processing. If “NO” is determined in the step T8, that is, if there is no deceleration tendency, it is determined whether or not the speed change at that time is an acceleration tendency (step T9). If the driver is accelerating intentionally, the control circuit 10 determines that it is not necessary to support the provision of information by this system, and returns to step T1 to return to the above-described processing. repeat.
[0034]
If there is no tendency to accelerate, the control circuit 10 determines that the vehicle is traveling as it is without recognizing the state of the red light, and the control circuit 10 makes a control determination on how to provide information (step T10). Here, when the information of the red signal is received from the roadside device 5 for the first time, the control circuit 10 outputs the warning sound by the alarm device 12 to notify the driver because the warning is 0 times ( Step T11).
[0035]
When the warning operation has already been performed, that is, when the information of the red light has been received from the roadside device 5 two or more times and the notification operation has been performed by the warning sound before, “one warning has been completed” is displayed. Judge and shift to step T12. Here, a control signal is output to the brake control system 13 to apply a light brake to the brake control mechanism 14. In other words, this makes the driver aware that the traffic light has changed to a red light. As a result, even when the driver is inadvertent, the driver can feel that the vehicle is automatically switched to the red light by applying the light brake.
[0036]
FIGS. 5A and 5B show the packet format of the transmission signal of the roadside device 5 and the packet format of the transmission signal of the on-vehicle device 7 when the above-described communication processing is performed. The transmission signal of the roadside device 5 is, in order from the beginning of the packet, (1) a communication start specification signal, (2) a vehicle speed calculation (transmission time) signal and a signal color signal, and (3) a vehicle inspection information (total length, registration No.) request. The signal, (4) stop distance (communication area) information signal, and (5) communication end specification signal are set.
[0037]
The transmission signals of the on-vehicle device 7 are (1) a communication start specification signal, (2) a reception time (roadside transmission time) signal, (3) a vehicle inspection information (full length, registration No.) signal, and (4) in order from the beginning of the packet. Communication end specification signal is set. Of these signals, the vehicle inspection information is used for practical use in a second embodiment to be described later, and it suffices to set the signals as needed.
[0038]
FIG. 6 shows the relationship between the stopping distance and the vehicle speed in various cases 1 to 3 when the information of the red light is provided to the vehicle-mounted device 7 according to the above procedure. In FIG. 6, the deceleration map set by the on-vehicle device 7 is shown by a continuous solid line in the figure, and in case 1, the driver notices the red signal in the first warning operation and applies a brake to this deceleration map. In this case, the vehicle is decelerated and stopped.
[0039]
Case 2 is a case in which the driver does not notice the notification operation by the second light brake control after receiving the warning at the time of the first reception, and first notices at the time of the third light brake control. At this time, since the vehicle deviates greatly from the planned model pattern of the deceleration map, it is necessary to stop with a brake within a short stopping distance, but still, it was possible to stop without entering the intersection 2. Is the case.
[0040]
In case 3, when the first warning is given, the driver may be aware, but the vehicle 1a is in a tendency to accelerate, and as described above, it is assumed that the driver does not intend to stop. This is a case in which the assistance of the stop notification operation is interrupted by the control of the control.
[0041]
According to the present embodiment, the roadside device 5 and the on-vehicle device 7 are provided, and when the vehicle 1a approaches the intersection 2 and the signal changes to a red light, the signal information is provided from the roadside device 5. In addition, since the in-vehicle device 7 performs the notification operation, even if the driver is inadvertent, it is possible to assist in quickly recognizing the state of the traffic light.
[0042]
(Second embodiment)
FIG. 7 to FIG. 9 show a second embodiment of the present invention. The difference from the first embodiment is that such a system is provided in most of the automobile 1 and the traffic signal 3 which are targeted, This is to perform control assuming that the infrastructure is maintained.
[0043]
In other words, in this case, it is assumed that the vehicle-mounted device 7 is mounted on almost 100% of the vehicles 1. Therefore, when there are a plurality of vehicles 1 entering the communication area 6, each vehicle 1 is surely mounted. It can be controlled so that it can be stopped. FIG. 7 shows a control program by the roadside device 5. Here, in addition to the program of the first embodiment, a process of creating a stop map in step S5 following step S4 (step S5) is added.
[0044]
When the in-vehicle device 7 enters the communication area 6 and receives a signal indicating that the signal is a red light, the stop distance according to the traveling speed at that time is calculated. FIG. 8 shows an example thereof. For example, in case A, the speed at the time of approach is high, and the stopping distance is long in the pattern of the deceleration map. In case B, the speed at the time of entry of the vehicle 1 is moderate, and in case C, the vehicle 1 is in a low speed state. Therefore, according to the pattern of the deceleration map, the stopping distance gradually decreases.
[0045]
On the on-vehicle device 7 side, if there is already a preceding vehicle 1 to enter the communication area 6 and stop, the stopping distance at that time is the vehicle length and the inter-vehicle distance of the preceding vehicle 1. Is subtracted, so that a deceleration map can be obtained based on the information. Thereby, in each vehicle 1, a stop operation based on an appropriate deceleration map can be performed.
[0046]
On the other hand, the roadside device 5 requests the vehicle 1 entering the communication area 6 one after another to the vehicle-mounted device 7 for data indicating the total length thereof as the vehicle inspection data, and can stop from the obtained total length information of the vehicle. Calculate the condition. As shown in FIG. 9, when a plurality of vehicles A, B, C,..., N and n enter as the vehicle 1 from the time when the red light is switched, the control device 8 controls the vehicle lengths A and B. , C,..., N, the required inter-vehicle distance is added to calculate the total lengths LA, LB, LC,..., LN required for each vehicle, and the distance obtained by adding them is the distance of the communication area 6. It is determined whether L does not exceed (see FIG. 9B).
[0047]
If this condition is satisfied, the vehicle can be stopped. However, if the added length exceeds the distance L, a collision may occur if the driver is unaware in the worst case. Therefore, in preparation for such a situation, we will prepare for notification to the authorities or report that there is a risk of collision.
[0048]
According to the second embodiment, by establishing a system as an infrastructure, it is possible to provide the driver of the on-vehicle device 7 with more advanced information from the roadside device 5 and support for driving. Will be able to
[0049]
(Other embodiments)
The present invention is not limited to the above embodiment, but can be modified or expanded as follows.
[0050]
In the above embodiment, the case where the present system is applied to the traffic light 3 at the intersection 2 is shown, but the present system can be applied to a traffic light without the intersection 2 such as a traffic light for pedestrian crossing.
[0051]
The control circuit 10 of the in-vehicle device 7 can output a signal of the notification operation to the car navigation device 15 to perform the notification operation.
[0052]
The roadside device 5 can be configured to be attached not only to the traffic lights 3aa and 3bb but also to 3a to 3d or the like, or can be configured to be provided separately from the traffic lights 3.
[Brief description of the drawings]
FIG. 1 is an electrical block diagram showing a first embodiment of the present invention; FIG. 2 is a perspective view showing a schematic configuration of the present system; FIG. Flowchart of a control program for the roadside unit. FIG. 5 is an explanatory diagram of a packet format of a transmission signal of the roadside unit and the on-vehicle unit. FIG. FIG. 4 corresponding to FIG. 4 showing a second embodiment of the present invention. FIG. 8 is an explanatory diagram of an operation of a deceleration map. FIG. 9 is an explanatory diagram of an operation of a stop map.
1 is an automobile (vehicle), 2 is an intersection, 3a to 3d, 3aa, 3bb are traffic lights, 4a to 4d are roads, 5 is a roadside machine, 6 is a communication area, 7 is an onboard machine, 8 is a control device, and 9 is a DSRC. A communication device, 10 is a control circuit, 11 is a DSRC communication device, 12 is an alarm (notifying means), 13 is a brake control system, 14 is a brake control mechanism, and 15 is a car navigation device.

Claims (9)

A roadside device that transmits a signal indicating at least a red light state among the lighting states of the traffic light,
An in-vehicle device mounted on a vehicle and capable of receiving a signal indicating a state of the signal from the roadside device,
A red light stopping system comprising: a notifying unit that, when the on-vehicle device receives a signal indicating a lighting state of the red light of the traffic light, performs a notification operation for prompting a driver of the vehicle to stop. The red light stop system according to claim 1,
The communication area of the roadside unit is a distance at which the driver can start a braking operation and stop at the position of the traffic light when the notifying operation is performed by the notifying unit while the vehicle is traveling at a legal speed. A red traffic light stop system, which is set as described above. The red light stop system according to claim 2,
The communication between the roadside device and the on-vehicle device is performed using a Dedicated Short-Range Communication (DSRC) communication system. The red traffic light stop system according to any one of claims 1 to 3,
The on-vehicle device is configured to, when receiving a signal indicating a lighting state of a red signal of the traffic signal, cause the notification unit to perform a notification operation on condition that the traveling state of the vehicle does not tend to decelerate. A red light stop system. The red traffic light stop system according to any one of claims 1 to 4,
The in-vehicle device is configured to perform a braking control such that a driver can feel the vehicle when the vehicle does not shift to the deceleration tendency after performing the notification operation by the notification unit. Signal stop system. The red light stop system according to claim 5,
The red-light stoppage system according to claim 1, wherein the on-vehicle device does not execute the braking control when the vehicle is accelerating after performing the notification operation by the notification unit. The red light stop system according to any one of claims 1 to 6,
The roadside device transmits a vehicle inspection information request signal requesting the in-vehicle device to transmit information on the length of the vehicle, creates a stop map based on a response signal from the in-vehicle device, and performs communication. A red traffic light stop system configured to determine whether a vehicle existing in an area can be stopped without collision. The red light stop system according to claim 7,
The red light stopping system, wherein the on-vehicle device is configured to respond to the vehicle inspection information request signal transmitted from the roadside device when the vehicle inspection information request signal is received for the first time in the communication area. The red light stop system according to any one of 1 to 8,
When the on-vehicle device receives a signal indicating the lighting state of the red signal of the traffic light from the roadside device, the on-vehicle device detects the relationship between the distance and the speed from the received position to the stop position, and stops at the position to stop. Red light stop system configured to create a deceleration map for the vehicle.

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