JP2886325B2 - Relative position measurement system for nearby vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to both information obtained by automatically measuring a relative positional relationship with a nearby vehicle traveling on the front, rear, left and right of a vehicle in road traffic, Information obtained by individual communication between vehicles
The present invention relates to a system for measuring a relative position with a nearby traveling vehicle having an inter-vehicle communication function for providing a driving support system for realizing a safe driving of an automobile and a smooth traffic flow.

2. Description of the Related Art Various types of rear-end collision prevention sensor systems have been devised in order to recognize the distance between a preceding vehicle traveling on the same lane and a host vehicle for the purpose of driving safely. The most common type is a radar-type rear-end collision prevention sensor using microwaves or millimeter waves. The radar wave emitted from the own vehicle receives a reflected wave reflected by the body of the preceding vehicle, and the propagation delay or Doppler of the radio wave is received. It measures the inter-vehicle distance by observing the frequency change due to the effect.

On the other hand, for the purpose of automatic measurement of traffic flow, research and development of an automatic recognition system of the number plate of a running vehicle using a CCD camera is under way.In this case, the CCD camera is fixed on the road structure, and the background is generally However, image processing for recognition requires considerable processing power (for example, the Transactions of the Society of Instrument and Control Engineers (19)
89) vol.25, No.2P243-245).

(Problems to be Solved by the Invention) The conventional rear-end collision prevention sensor system as described above is still insufficient in terms of safe driving under recent and increasingly complicated road traffic conditions. That is, it is difficult for a rear-end collision prevention sensor using a radio wave to identify a preceding vehicle traveling on each lane in the case of a road having a plurality of lanes. Further, there is a serious drawback in that a radiated radar wave from a vehicle traveling in the oncoming lane is directly received and becomes an interference wave for reflected wave reception from a preceding vehicle which should be originally observed.

On the other hand, the measurement system based on the image processing of the CCD camera assumes that the camera image is intended for natural light, so it may be different between day and night, changes in road lighting, sudden changes in brightness near the entrance and exit of tunnels, etc. In addition to the inherent drawback that it is difficult to deal with, the camera images of the running vehicle are all moving images including the background, and the preceding vehicle is extracted and recognized In order to process such a large amount of information at a high speed, expensive processing devices are required, and these are serious obstacles to the practical use of the system.

In addition, on a complicated road having a plurality of lanes, it is necessary to identify and recognize a plurality of traveling vehicles, and it is preferable that the information of the traveling state within a range several vehicles before the lane is recognized. In order to satisfy such demands, it is necessary to recognize individual vehicle-specific codes by an inter-vehicle individual communication function and to mutually exchange traveling state information of a group of preceding vehicles.

The present invention has been made in order to solve the above-described problems, and can obtain a highly reliable relative position between vehicles by simple image processing, and can also communicate with nearby traveling vehicles that can communicate individually between vehicles. An object of the present invention is to provide a relative position measurement system.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a time division transmission controller for selecting and outputting an interrogation signal or a first individual information signal, and a signal from the time division transmission controller. Transmitter transmitting infrared signals to the preceding vehicle by infrared light, a first infrared light receiver receiving and outputting an individual information signal by infrared light from the preceding vehicle, and a sign response from the preceding vehicle A CCD camera that receives infrared light that is a signal and blocks visible light, a second infrared light receiver that receives and outputs an interrogation signal or individual information signal by infrared light from a following vehicle, A shared transmission controller for selecting and outputting a control signal or a second individual information signal corresponding to the interrogation signal; and transmitting infrared light as a beacon response signal to a following vehicle by a control signal from the shared transmission controller. , The second individual information signal is transmitted to a following vehicle by infrared light. A first infrared light marker that transmits to both, and a first infrared light marker that is located at a predetermined distance from the first infrared light marker and transmits infrared light that is a marker response signal to the following vehicle by the control signal. A second infrared light marker is provided in each vehicle, and at the time of measuring the relative position between the vehicle and the preceding vehicle, an interrogation signal is transmitted from the vehicle to the preceding vehicle, and the preceding vehicle sends the interrogation signal to the vehicle in response to the interrogation signal to the interrogation signal. Transmitting a signal, analyzing the infrared light image corresponding to the beacon response signal in the vehicle to extract relative position information, transmitting and receiving an individual information signal when communicating between the vehicle and the preceding vehicle, The position measurement and the communication are executed in a time-division manner.

(Operation) First, the system for measuring the relative position with respect to a nearby traveling vehicle, which is one of the operation modes of the present invention, is basically based on observation of two infrared light marking machines of a preceding vehicle, Whereas the visible reflected light image due to road illumination light greatly changes depending on the surrounding environment conditions, the present invention targets an image of only a light marker as an infrared light source defined in a state where visible light is blocked by a filter. Therefore, an extremely simplified image excluding unnecessary moving image components such as the background is removed, and image processing for extracting position information of the preceding vehicle can be greatly simplified. In addition, the operation of the infrared light marking machine is made a question answering form from the following vehicle, and the following vehicle transmits the light beacon signal only in the time slot required for observation, so that the vehicle traveling in the oncoming lane It is easy to distinguish the signal from the transmission light such as the interrogation signal or the individual communication signal.

Next, the present invention, in addition to the operation mode of relative position measurement with the nearby traveling vehicle described above, by driving the operation mode of performing individual communication between vehicles with the preceding vehicle in a time-sharing manner, most of the A system configuration that allows in-vehicle equipment to be shared for both operating modes has been realized. In addition, both operation modes can be controlled by the centralized control of the vehicle's line controller, and measurement and communication can be performed even for vehicles traveling in multiple lanes while avoiding collisions in time slots while identifying them individually. And

The driving-related information transmitted by each vehicle through the individual communication between the vehicles includes primary information of the own vehicle such as a unique code of the vehicle, traveling speed information, acceleration / deceleration information, lane change information, and the like. And the secondary information (average traveling speed, average inter-vehicle distance information, emergency information, etc. within a range of several vehicles) obtained from the information processing is applied.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of the present invention.
(A) is a diagram showing a mounting position of a device in a traveling vehicle,
(B) is a block diagram showing a signal system. In FIG. 1, reference numeral 1a denotes a traveling vehicle, and 1b denotes a vehicle traveling ahead of the vehicle 1a (represented by subscripts a and b corresponding to the vehicle and the preceding vehicle, respectively). In front of vehicles 1a and 1b, CCD cameras 4a and 4b equipped with filters that block visible light and pass only infrared light are mounted forward on the vehicle center line, and infrared light is transmitted next to it. Infrared light transmitters 2a and 2b and infrared light receivers 3a and 3b that receive infrared light are mounted forward. In addition, at the rear of the vehicles 1a and 1b, two infrared light markers 6a and 7a, 6b and 7 that transmit two infrared lights at a predetermined distance 2s are provided.
b is mounted rearward, and one infrared light receiver 8a, 8b for receiving one infrared light is mounted rearward. In addition, the line controllers 9a, 9b shown in FIG.
(9b), beacon transponders (10a), 10b, image processing devices 11a, (11
b), shared transmission controller (13a), 13b, time-division transmission controller 16
a, (16b), and time-division reception controllers 18a, 18b (devices in parentheses are not shown).

Next, the operation of this embodiment will be described with reference to FIGS. FIG. 2 shows an example of an infrared light image observed by the CCD cameras 4a and 4b.

The operation according to the present embodiment includes an operation mode (hereinafter referred to as a measurement mode) for measuring a relative position between the vehicle 1a and the preceding vehicle 1b,
There is an operation mode (hereinafter referred to as a communication mode) in which communication is performed individually between the vehicle 1a and the preceding vehicle 1b. The measurement mode and the communication mode function in a time-division manner and have a fixed cycle (for example, 1 to 10 times / Seconds). Line controllers 9a, (9
b) outputs a control signal for controlling each device in order to smoothly perform switching and repetition for making the measurement mode and the communication mode function in a time-division manner, and each device is designated by the control signal. A predetermined operation is performed in a time slot.

 First, the operation in the measurement mode will be described.

The time-division transmission controller 16a transmits a query signal to the infrared light transmitter 2a at the time slot designated by the line controller 9a, a unique code of the vehicle 1a, and a time slot number code indicating the time slot in the communication mode. Is sent. The infrared light transmitter 2a transmits these signals to the preceding vehicle 1b by infrared light. Upon receiving the infrared light from the following vehicle 1a, the infrared light receiver 8b of the vehicle 1b demodulates the signal and sends it to the beacon transponder 10b. When the sign transponder 10b detects the interrogation signal from the following vehicle 1a,
(About 0.01 to 0.1 second), and instructs the infrared light marking devices 6b and 7b to transmit the tag response signal. The infrared light marking devices 6b and 7b transmit the infrared light that is the tag response signal to the vehicle 1a following the predetermined time. The CCD camera 4a of the following vehicle 1a receives the infrared light. In this case, a filter 5a that blocks visible light and passes only infrared light is attached to the front end of the CCD camera 4a, so that visible light, which is an unnecessary moving image component such as a background, is blocked. Only the images of the two infrared light marking devices 6b and 7b of the preceding vehicle 1b are observed. FIG. 2 is an example of a screen of an infrared light image by the CCD camera 4a, and the images Q1 and Q2 correspond to the infrared light marker 6b and 7b. Image processing device 1
1a analyzes the image corresponding to the time slot designated by the line controller 9a among the images, extracts relative position information with respect to the preceding vehicle 1b, and outputs it from the relative position information terminal 12a.

The relative position information can be extracted as follows. That is, on the screen shown in FIG. 2, the horizontal screen width (2qo) corresponds to the effective directional angle ± θ of the camera 4a in the horizontal direction with respect to the center line of the vehicle 1a. Also, the interval between the two infrared light marker images (Q1, Q2) in the screen and the center line of the screen are the center points of the two infrared light marker images (Q1, Q2). Observe the deviation, obtain the values normalized by the horizontal screen width (2qo) of the screen, respectively, and let ξ and 、 denote the inter-vehicle distance L between the vehicle and the preceding vehicle and the center of both vehicles, respectively. The line shift W is calculated from the following relational expression.

Next, the operation in the communication mode will be described.

In FIG. 1 (b), the time division transmission controller 16a sends the individual information signal from the individual information input terminal 17a to the infrared light transmitter 2a in the time slot specified by the line controller 9a. The infrared light transmitter 2a transmits this individual information signal to the preceding vehicle 1b by infrared light. The infrared light receiver 8b of the vehicle 1b receives the infrared light, demodulates the individual information signal, and
Send to 10b. The beacon transponder 10b, based on the time slot number code previously transmitted from the subsequent vehicle 1a, transmits the individual information signal from the subsequent vehicle 1a in the communication mode and the individual information signal of the own vehicle to the subsequent vehicle 1b in the communication mode. Since the time slot to be transmitted is recognized, the individual information signal from the following vehicle 1a is extracted and output from the individual information output terminal 15b according to the time slot, and from the individual information input terminal 14b at a predetermined time slot. Shared transmission controller so as to transmit the individual information signal of
Control 13b. The shared transmission controller 13b sends the individual information signal to the infrared light marking device 6b, and the infrared light marking device 6b transmits this to the following vehicle 1a by infrared light. The infrared light receiver 3a of the following vehicle 1a receives the infrared light, demodulates the individual information signal, and sends it to the time division reception controller 18a. The time-division reception controller 18a extracts the individual information signal in the time slot specified by the line controller 9a, and outputs the signal from the individual information output terminal 19a.

Thus, the vehicles 1a and 1b are the line controllers of the following vehicle 1a.
Communication is performed using a predetermined time slot of the communication mode under the centralized control of 9a. When transmitting the individual information signal from the preceding vehicle 1b, the individual information signal is transmitted with the unique code of the vehicle.

(Effects of the Invention) According to the present invention, since the specified infrared light marker image is targeted, the relative position measurement of a nearby traveling vehicle with high reliability can be performed with greatly simplified image processing. Becomes In addition, by adding an individual vehicle-to-vehicle communication function so that most of the in-vehicle devices are shared, the functions can be combined under a low-cost device configuration. In other words, in addition to the information measured by the own vehicle, information obtained by using inter-vehicle individual communication from a nearby vehicle is processed and complementarily referred to, so that various advanced driving support systems can be put to practical use. Become like

The overall effect of the present invention contributes significantly to preventing traffic accidents and realizing high safety and smooth traffic flow.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing a screen by a CCD camera. 1a, 1b …… Vehicle, 2a, 2b …… Infrared light transmitter, 3a, 3b, 8a, 8b
…… Infrared light receiver, 4a, 4b …… CCD camera, 5a …… Filter, 6a, 7a, 6b, 7b …… Infrared light marker, 9a …… Line controller, 10b …… Signal transponder, 11a …… Image processing device, 12a…
… Relative position information terminal, 13b …… Common transmission controller, 14b, 17a
... individual information input terminal, 15b, 19a ... individual information output terminal, 16a ... time division transmission controller, 18a ... time division reception controller.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-196488 (JP, A) JP-A-2-232515 (JP, A) JP-A-52-101537 (JP, A) JP-A-61-196488 28884 (JP, A) JP-A-63-153489 (JP, A) JP-A-52-156655 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01S 7/48-7 / 51 G01S 17/00-17/95 B60R 21/00

Claims (2)

(57) [Claims] 1. A time division transmission controller for selecting and outputting an inquiry signal or a first individual information signal, and an infrared light transmission for transmitting a signal from the time division transmission controller to a preceding vehicle by infrared light. And a first infrared light receiver that receives and outputs an individual information signal based on infrared light from the preceding vehicle, and receives a sign response signal from the preceding vehicle, and blocks visible light. A second infrared light receiver for receiving and outputting an interrogation signal or individual information signal by infrared light from a following vehicle; a control signal or a second individual information signal corresponding to the interrogation signal A common transmission controller that selects and outputs a signal, an infrared light that is a beacon response signal is transmitted to a following vehicle by a control signal from the common transmission controller, and the second individual information signal is transmitted using infrared light. A first infrared light marker for transmitting to the vehicle; A second infrared light marking device, which is located at a predetermined distance from the infrared light marking device and transmits an infrared light which is a marker response signal to the following vehicle by the control signal, is provided in each vehicle; When measuring the relative position with respect to the vehicle, the vehicle transmits an interrogation signal to the preceding vehicle, the preceding vehicle transmits a marker response signal to the interrogation signal to the vehicle, and an infrared light corresponding to the marker response signal in the vehicle is transmitted. Analyzing nearby images to extract relative position information, transmitting and receiving individual information signals during communication between the vehicle and the preceding vehicle, and performing relative position measurement and communication in a time-division manner; A system for measuring the relative position with the vehicle. 2. A line controller for designating a time slot for transmitting an interrogation signal, a time slot for transmitting a beacon response signal, and a time slot for transmitting an individual information signal, is provided in each of the vehicles. The relative position measurement system for a nearby traveling vehicle according to claim 1, wherein the relative position measurement and the communication are executed based on: