JPH07225900A - Crossroad vehicle sensor device - Google Patents

Abstract

PURPOSE:To prevent the suddenly meeting accidents of vehicles on a crossroads by emitting a laser beam to a reflector provided on the crossroads and receiving the light reflected from the opposite party vehicle to calculate the relative speed to the opposite party vehicle. CONSTITUTION:The laser beam transmitting and receiving parts are formed at the front side of a vehicle. An inter-vehicle distance calculator 30 calculates the inter-vehicle distance based on the data received from a laser head 2, and a relative speed arithmetic circuit 31 calculates the relative speed to the vehicle ahead and the speed of this vehicle based on the inter-vehicle distance data. Then a curved road reflector judging circuit 36 judges a curved road reflector. The optical path of the laser beam emitted from its own vehicle is changed by the reflector provided on a crossroads. Then the reflector irradiates the laser beam to the vehicle coming on a wrong way and the optical path of the reflected light of the vehicle is changed again by the reflector. The reflected light of the wrong-way vehicle is led to its own vehicle. Thus the wrong-way vehicle is detected by the time difference caused between the emitted and reflected waves.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a side road vehicle detection device for allowing a vehicle to travel safely when it enters a crossroads or the like.

[0002]

2. Description of the Related Art Conventionally, when a car is approaching a crossroads, a person driving the car is statistically likely to have an accident with a partner vehicle approaching from sideways on both sides in front of the car. There are so many accidents that pop-out accidents are unpredictable and often result in accidents. This accident has a lot to do with the driving morals of the driver: there are cars sprinting at intersections even when there is a traffic light and there are red traffic lights. Without being protected. Therefore, in terms of traffic safety measures, when a car enters a crossroads, it is obligatory to stop or drive slowly, and penal regulations are also stipulated.

[0003]

However, in the conventional mechanism of the automobile, in order to confirm the other vehicle approaching from the side roads on both sides in front, the side mirror of the automobile has a blind spot. There will be a limit. There was a problem that it was difficult to confirm if a blind spot was reached even if the vehicle was temporarily stopped or driven slowly, and it was difficult to prevent an accident. The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is that, when a car enters a crossroads, a person driving the car enters from the side roads on both sides in front. It is an object of the present invention to provide a side road vehicle detection device capable of confirming an oncoming vehicle and preventing an accident where the vehicle may be encountered.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems. According to the invention described in "Claim 1," a laser emitting portion and a laser provided on the front side in front of the laser are provided. It is arranged so that it is located in the upper center of the intersection of the vehicle and the intersection with the light receiving part, and the laser light emitted from the laser emitting part of the vehicle entering the intersection comes from the front left and right direction to the intersection. A reflector whose angle is set so as to irradiate the other vehicle and enter the reflected light reflected from the other vehicle and enter the intersection and return to the laser light receiving part of the vehicle, and enter the intersection. The laser light emitted from the laser emitting part and the reflected light reflected from the other vehicle, which are provided in the vehicle, are received by the laser light receiving part, the time difference between them is calculated, and the relative speed with the other vehicle Characterized in that it is composed of an arithmetic unit for the calculation.

[0004]

According to the lateral road vehicle detection device having the above structure, the reflector is installed at the crossroad, and the laser light or the radio wave emitted from the own vehicle is bent by the reflector to travel along the lateral road. By irradiating an incoming vehicle and guiding the laser or radio wave reflected by that vehicle with a reflector again to guide it to the vehicle, a side vehicle is detected from the time difference between the emitted wave and the reflected wave to prevent an accident. It will be possible.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a side road vehicle detection device according to the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view of a safe inter-vehicle distance when the side road vehicle detection device according to the present invention is used, FIG.
4 is a circuit block when the laser radar head used in the present invention is used in a rear-end collision warning device, FIG. 3 is an explanatory view showing the internal configuration of the laser radar head used in the present invention, FIG.
3 is a block diagram of the laser radar head of FIG. 3, FIG. 5 is a characteristic diagram showing a reflection characteristic of a vehicle rear portion, FIG. 6 is an explanatory diagram showing a refraction state of light in a corner cube, and FIG. 7 is an information processing block used in the present invention. FIG. 8, FIG. 8 is a conceptual diagram of a side road vehicle detection device of the present invention, FIG. 9 is an explanatory diagram showing a light reflection state of a reflector used in the present invention, and FIG. 10 is a laser beam emission of the reflector used in the present invention. It is explanatory drawing which shows a receiving state. At present, an “inter-vehicle distance measuring device” as shown in FIG. 1 is being studied for preventive safety of automobiles. Figure 1
Is an explanation of the concept of safe inter-vehicle distance. The safe inter-vehicle distance is calculated by the following equation (1). Here, Dr: safe inter-vehicle distance β: deceleration of preceding vehicle Vf: own vehicle speed V ₂ : preceding vehicle speed T: idle time α: deceleration of own vehicle

Therefore, if the parameters Vf, Vα, T, α, and β are given, the safe vehicle distance under the conditions can be obtained based on the equation (1). When applied to an actual device, T greatly depends on the reaction time and the judgment time of the driver among these parameters, and the deceleration of the own vehicle and the preceding vehicle depends on the braking limit performance of each vehicle. However, since it greatly changes depending on the vehicle type, road surface conditions, loading conditions, etc., it is simplified to α = β ≡ α ··· (2), and the driver selects from a plurality of parameters according to the situation. It is necessary to devise such as selecting.

FIG. 2 is a block diagram of a rear-end collision warning device. It is attached to the own vehicle and emits a laser beam 3 from the laser radar head 2 on the light emitting side, and the reflected wave 4 reflected by the vehicle ahead is received again by the laser radar head 2 and processed by the signal processing circuit 5a. , The display 5 emits a light, and a buzzer or the like gives an alarm. In the figure, 5b is a vehicle speed sensor of the own vehicle.

FIG. 3 is a block diagram of the laser radar head 2. The laser beam 3 includes a light transmitting unit 6 and a light receiving unit 7. As shown in the figure, the light transmitting unit 6 is roughly configured by a laser diode 8 that emits the laser beam 3, a light transmitting lens 9a, and a laser drive circuit 9b. The light receiving section 7 is for receiving the reflected wave 4 of the laser beam 3 emitted from the light transmitting section 6, and includes the honeycomb filter 10, the Fresnel lens 11 having the out-of-field filter, the photodiode 12, and the amplifier 13. It is roughly configured. The honeycomb filter 10 in the light receiving unit 7 is a filter that prevents malfunction due to visible light. Further, the distance detection circuit 14 receives the reflected wave 4 of the laser beam 3 emitted from the light emitting and emitting unit 6 and measures the distance to the vehicle in front from the time difference. FIG. 5 is a reflection characteristic diagram at the rear portion of the vehicle, and FIG. 11 shows an example of laser radar specifications. FIG. 4 shows a laser radar head 2
3 is a circuit block diagram for explaining the details of the structure of FIG.
The light emitting / receiving unit 6 has a laser diode (LD) 8 and emits an infrared laser beam 3 having a pulse width of 70 ns with a period of 6 kHz and emitting it through a lens 16.
The laser beam (reflected wave) 4 reflected by the forward vehicle 40 returns to the light receiving unit 7. In the light receiving section 7, the laser beam 4 is input to a pin photodiode (photodiode) 12 which is a light receiving element provided in the light receiving section 7 via the honeycomb filter 10 and the Fresnel lens 11. Here, a dirt detection circuit 15 for the surface glass, a high temperature detection circuit 16 that cuts the laser beam at high temperatures, a light emission power detection circuit 17 that detects a reduction in the emission power of the laser beam, and a jamming detection circuit that detects the influence of sunlight or the like. It has 18 functions. The pin photodiode 12 is used as the light receiving element used in the light receiving unit 7, but the light receiving element is not limited to this as long as it has high light receiving sensitivity. The time difference between the laser beam 3 emitted by the gate timer 19 in the figure and the laser beam 4 which is the reflected wave received is detected, converted into a signal of inter-vehicle distance, and guided to the information processing block of FIG. 7. 2 in the figure
Reference numerals 0 and 21 are oscillation circuits, 22 is a light receiving amplifier, 23 is a distance counter, 24 is a signal conversion circuit, and 25 is an optical link circuit. Further, 26 is a laser diode light emission switching drive circuit, 27 is a laser diode drive high voltage power supply unit for supplying drive power to the laser diode 8, 2
Reference numeral 8 denotes a power supply unit for applying power to the laser diode driving high-voltage power supply unit.

FIG. 7 is an information processing block diagram. The own vehicle speed calculation is performed by the own vehicle speed calculation unit 29 based on the pulse input from the vehicle speed sensor 5b. The inter-vehicle distance calculation is based on the data from the laser radar head 2
Calculated as 0. In the relative speed calculation, the relative speed with respect to the front vehicle 40 and the front vehicle speed are calculated by the relative speed calculation circuit 31 based on the inter-vehicle distance data. The safe inter-vehicle distance is calculated based on the vehicle speed, the vehicle speed in front, and the state of the setting switch X. Here, the alarm stop determination is performed by the alarm stop determination circuit 32, and the front inter-vehicle distance determination is performed by the front inter-vehicle distance determination circuit 33.
Then, the constant speed / constant inter-vehicle distance determination circuit 34 determines
The front stop vehicle determination circuit 35 performs the front stop vehicle determination, and the curve road reflector determination circuit 36 performs the curve road reflector determination. For the alarm output, the inter-vehicle distance and the safe inter-vehicle distance are compared with each other, and if there is an alarm condition, a command signal for outputting an alarm sound in the alarm generation determination circuit 37 is output to the alarm generation circuit 38. Display (monitor) output section 3
9c is set to display an inter-vehicle distance and an abnormality when an abnormality occurs. Also, the braking distance calculation circuit (Dr) 39
“A” calculates the braking distance when the preceding vehicle is running, and the braking distance calculation circuit (Ds) 39b calculates the moving distance when the preceding vehicle is stopped.

As described above, the inter-vehicle distance measuring apparatus currently being researched irradiates the infrared laser beam 3 having a short pulse width forward, and the reflected wave 4 which is the reflected light from the vehicle 40 in front is emitted. It measures the distance between vehicles from the time it takes to return. The side road vehicle detection device Y according to the present invention applies the principle of measuring the inter-vehicle distance of a forward vehicle in the past.

FIG. 8 is a conceptual diagram of the side road vehicle detection device Y. The laser beam 3 emitted from the own vehicle 1 hits the reflector A or the reflector B installed on the intersection, is reflected, and hits the side road vehicles 41 and 42. Sidecar 4
The laser beam 3 reflected by 1, 42 returns to the laser radar head 2 of the own vehicle 1 along the same path.

FIG. 9 shows the state of reflection of the reflector A. The laser beam 3 from the light transmitting unit 6 of the own vehicle 1 is directed upward to the reflector A. The laser beam 3 reflected by the reflector A is directed downward and strikes the side road car 41. The reflected wave 4 returns to the laser radar head 2 of the vehicle 1 through the same road.

FIG. 10 shows a practical reflector A. The direction of the reflector A is changed so that the front vehicle 40 can be used. It has a triangular pyramid shape.
One side is used in the forward direction and one side is used in the reverse direction. The two triangular pyramids intersect vertically, and the left and right sideways vehicles 41 and 42 are simultaneously detected by the reflection of the laser beam 3 of the vehicle 1.

FIG. 6 is an explanatory diagram for explaining the internal structure of the reflector A. Light incident on the corner cup is
Total reflection is repeated three times in the inside, and the light is efficiently reflected in the incident direction. Invention reflectors A and B
Applies this principle, and has a structure in which strong light is reflected at right angles. According to the present invention having the above-described configuration, the reflectors A and B are installed at the crossroads, and the laser beam 3 emitted from the light transmitting unit 6 of the own vehicle 1 hits the reflector A or the reflector B and travels along the side road vehicle 41. , 42, and the laser beam 4 reflected by the light receiving portion 7 of the vehicle 1 is bent again by the reflectors A and B to be guided to the vehicle 1. ) Since the presence of the side road vehicles 41, 42 can be detected in advance from the time difference of 4 and the distance between them can be determined in advance, an accident at a crossroad can be prevented in advance. If the reflector is installed on the curved road, the positional relationship between the traveling vehicle and the oncoming vehicle can be confirmed.

[0015]

According to the present invention having the above-described structure, a reflector is installed at a crossroad, and a laser beam or a radio wave emitted from a light transmitting section of the vehicle is bent by the reflector to travel along a side road. By irradiating the car and reflecting the laser or radio wave reflected by the car again with a reflector and guiding it to the own car, the existence and inter-vehicle distance can be distinguished in advance from the time difference between the emitted wave and the reflected wave.
Various effects will be exhibited, such as being able to prevent accidents.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a safe inter-vehicle distance when a side road vehicle detection device according to the present invention is used.

FIG. 2 is a circuit block diagram when the laser radar head used in the present invention is used in a rear-end collision warning device.

FIG. 3 is an explanatory diagram showing an internal configuration of a laser radar head used in the present invention.

FIG. 4 is a block diagram of the laser radar head of FIG.

FIG. 5 is a characteristic diagram showing a reflection characteristic of a rear portion of the vehicle.

FIG. 6 is an explanatory diagram showing a refraction state of light in a corner cube.

FIG. 7 is an information processing block diagram used in the present invention.

FIG. 8 is a conceptual diagram of a side road vehicle detection device of the present invention.

FIG. 9 is an explanatory diagram for explaining a light reflection state of a reflector used in the present invention.

FIG. 10 is an explanatory diagram showing laser light emission and reception states of the reflector used in the present invention.

FIG. 11 shows the specifications of the laser radar head.

[Explanation of symbols]

 Y ... Sideways vehicle detection device A, B ... Reflector 1 ... Own vehicle 2 ... Laser radar head 3 ... Laser beam 4 ... Reflected wave 5 ... Display 6 ... Light emitting part 7 ... Light receiving part 8 ... Laser diode 9 ... Laser driving circuit 10 ... Honeycomb filter 40 ... Forward vehicle 41, 42 ... Sideways vehicle

Claims (1)

[Claims] 1. A vehicle equipped with a laser light emitting portion and a laser light receiving portion provided on the front side in the front, and a laser for a vehicle which is arranged so as to be located above the center of an intersection of a crossroad and enters the intersection. A laser light receiving unit of a vehicle that irradiates the opposite vehicle coming from the front left and right direction toward the intersection with the light emitted from the light emitting unit and inputs the reflected light reflected from the other vehicle to enter the intersection. A reflector whose angle is set to return to, and a laser light emitted from the laser emitting section and a reflected light reflected from the other vehicle, which are provided in the vehicle entering the intersection, are received by the laser receiving section, A lateral road vehicle detection device comprising: a calculating unit that calculates the time difference and calculates a relative speed with respect to the other vehicle.