JPH05264731A - Detector for reflecting body - Google Patents

Abstract

PURPOSE:To prevent an alarm which detects a distance of an object ahead and informs when there is a distance less than a safety distance from continuously sounding when an automobile comes near a road shoulder reflecting body buried in a curved road while the automobile is running on the curve. CONSTITUTION:When an automobile enters a curve and detects a road shoulder reflecting body, its detected distance varies in triangular waves. When the detected distance reduces to a safety distance Dr or less, an alarm is issued, while a rapid increase in distance is detected at point (a) and then second rapid increase in distance is detected at point (b), the alarm disappears. A travel distance from the points (a), (b) is measured by an A counter and if a rapid increase in distance is not detected even if a predetermined value has been run, inhibition of the alarm is canceled. At this time, the alarm is issued when the detected distance is at the safety distance or less, while no alarm is issued when the distance is larger than the safety distance. In addition even is an automobile has not run a predetermined distance, if the detected distance is X-20m or less as shown at point (d), the inhibition of the alarm is canceled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for measuring a distance between a vehicle and an object in front of the vehicle and issuing an alarm when the distance becomes smaller than a safe inter-vehicle distance. The present invention relates to a reflector detection device that does not give an alarm when the arrayed reflectors are detected as a front object.

[0002]

2. Description of the Related Art Conventionally, a device for confirming a safe inter-vehicle distance is widely known. This device emits ultrasonic waves and laser light from the front of the car and reflects it on the object in front,
The distance between the vehicle and the object in front is measured from the time from receiving and emitting this reflected light to the reception, and an alarm is issued when this measured distance becomes smaller than the specified safe inter-vehicle distance. Is configured. When a vehicle equipped with such a device approaches a curve while traveling, the roadside reflector gives an alarm. The shoulder reflectors are arranged at predetermined intervals on the shoulders on the outside of a road having a sharp curve, and reflect the light from the headlights to inform the driver that the road is a sharp curve.

When a vehicle equipped with the above-mentioned safety inter-vehicle distance confirmation device approaches a sharp curve, the driver operates the steering wheel along the curve to drive the vehicle between the vehicle and the shoulder reflector even if the vehicle is traveling normally. Since the distance is less than the safe inter-vehicle distance, an alarm is issued. This alarm is very annoying because it goes out while driving on a curve. In order to solve such a problem, for example, JP-A-62-62
A collision warning device and the like shown in Japanese Patent Publication No. 130500 has been proposed. However, such a collision warning device also has various problems.

FIG. 6 is a diagram showing how an automobile detects a roadside reflector while traveling on a curve, and FIG. 7 shows the waveform of the detection signal. 1 is a car, 2 is a sharply curved road, 3 is a plurality of shoulder reflectors arranged along the outer shoulder of the road 2 at predetermined intervals, and 4 is a transmitter (not shown) installed in front of the car. ) Is a beam such as a laser beam emitted from.

The reflected light reflected by the road shoulder reflector 3 after receiving the beam 4 is received, and the distance between the automobile 1 and the nearest road shoulder reflector 3 in front is detected from the time from transmission to reception. It As shown by the dotted line in FIG. 6, when the roadside reflector 3a detected by the automobile 1 running out of the range of the beam 4, the distance to the next roadside reflector 3b is detected. This detection operation is continuously performed as the vehicle 1 travels, and a detection distance of a waveform that changes in a sawtooth shape as the vehicle travels as shown in FIG. 7 is obtained. This detection distance starts to decrease from the detection distance s where there is a sudden change,
When the detection distance t of the closest approach is reduced, the shoulder reflector 3
a goes out of the beam 4, the next road shoulder reflector 3b is detected, and the detection distance rapidly increases. Detection distance is safe distance between vehicles Dr
An alarm will be issued if: The alarm sounds periodically each time the roadside reflector 3 is passed, which is very troublesome.

The collision warning device stores the detected distance s when it is detected and stores the detected distance s. The detected distance s is obtained by subtracting the sequentially detected distance i from the automobile 1 to the shoulder reflector 3. The difference (s-i) is monitored, and in the range where the value of the difference is smaller than a predetermined set value corresponding to the distance between the shoulder reflectors corresponding to (s-t), it is determined that the detected object is a stopped object. After that, the warning of the collision warning device is prohibited. That is, even if the detected distances s to t become equal to or less than the safe inter-vehicle distance, the alarm is not immediately issued, and when the detected distance difference (s-i) is smaller than the set value, the detected object in front is a stationary object and the road shoulder. Since it is determined that the object is the reflector 3 and the collision is not expected, it is not necessary to issue an alarm, and the alarm is prohibited from being issued. If the detected distance difference (s-i) is larger than the set value, an alarm is issued because the object currently detected is not a shoulder reflector, and if the detected distance difference (s-i) is too small, Since it is very close to the car 1, it is dangerous and the prohibition is lifted to give an alarm.

[0007]

However, in such a conventional apparatus as described above, it is determined whether or not the detected object is a stationary object based on the relative speed as described above, and when the stationary object is detected, the traveling distance is detected and Perform actions such as prohibiting alarms. When this operation is performed, ten or more pieces of distance data are required to obtain the relative speed, and it takes a long time to detect the distance data, which causes a problem that the detection of the traveling distance and the prohibition of the alarm are delayed.

[0008]

SUMMARY OF THE INVENTION The present invention detects a sudden increase in the detected distance after the detected distance can be measured by a signal from a means for measuring a traveling distance of a vehicle and a distance measuring means for measuring a distance to a front object. A means for outputting a sudden increase signal, a means for measuring the distance traveled by the vehicle from the time of sudden increase detection by the sudden increase signal, and a judgment as to whether or not the measured traveling distance after the sudden increase has reached a predetermined set value. A means for outputting a set value excess signal when the set value is reached, and an alarm operation signal when the distance to the object is less than or equal to the safe inter-vehicle distance, and an alarm operation when a sudden increase signal is generated twice in succession If a signal is generated, prohibiting the generation, canceling the prohibition when a signal exceeding the set value is generated, and when the distance to the object detects a sudden increase in the detection distance, a predetermined distance from the detection distance immediately before the rapid increase Reduced In which also provided an alarm control means for canceling the prohibition when it is away below.

[0009]

When a sudden increase in the detection distance is detected twice in a row, it is immediately judged that the reflector is a shoulder reflector and the generation of an alarm signal is prohibited, and the alarm keeps sounding while the vehicle is traveling on a curve. If the object in front is not a shoulder reflector,
Even if the vehicle travels to the set value, the next sudden increase in the detected distance is not detected, so the prohibition of the alarm is released. The prohibition is also canceled because the front object approaches and becomes dangerous even when the distance becomes equal to or less than the distance obtained by subtracting a predetermined distance from the detection distance immediately before the sudden increase.

[0010]

EXAMPLES The details of the present invention will be described below with reference to examples. FIG. 1 is a block circuit diagram showing an embodiment of the present invention. In the figure, 10 is a well-known distance measuring means installed in front of an automobile, which measures the distance from the time until the laser light is emitted and the reflected light is received to the front object, which is approximately 100 m. Up to the front object can be measured. It becomes impossible to measure when the object in front is further away or left or right. Reference numeral 4 is a launch beam, 11 is a control means including a microcomputer, and 12 is an alarm based on the alarm information output from the control means 11 when the distance between the automobile and the distance measuring object is equal to or less than a predetermined safe inter-vehicle distance. The alarm means 13 that is generated is a travel detection means that measures the travel distance of the automobile. The traveling detection means 13 outputs one pulse each time the vehicle travels a unit distance, and the traveling distance of the automobile can be measured by counting the number of pulses.

The control means 11 receives the distance signal from the distance measuring means 10 and detects a sudden increase in the detected distance, and outputs a sudden increase signal, and a sudden increase signal outputted from the sudden increase detection means 11a. And traveling detection means 13
From the vehicle, and the traveling distance measured by the traveling distance measuring means 11b after the rapid increase is a predetermined set value. The distance to the object measured by the travel distance determination means 11c that outputs a set value excess signal when a predetermined set value is reached and the distance measuring means 10 is less than or equal to the safe inter-vehicle distance. Occasionally generates an alarm operation signal for driving the alarm means 12,
If the alarm signal is generated when the sudden increase detection means 11a generates the sudden increase signal twice, the sudden increase signal serves as an alarm prohibition signal to inhibit the generation of the alarm operation signal, and the traveling distance determination means 11c. Is configured to include an alarm control means 11d for performing control such as releasing the prohibition when a set value excess signal is generated.

FIG. 2 is a diagram showing the relationship between the traveling distance of the automobile and the detected distance measured by the distance measuring means 10. This figure is basically the same as FIG. 7. When the vehicle approaches the curve and the detection distance can be measured from the point p and the shoulder reflector is detected, the detection distance decreases as the vehicle runs, and when the detection distance becomes less than the safe inter-vehicle distance Dr, alarm control is performed. An alarm operation signal is output by the action of the means 11d, and an alarm signal is generated from the alarm means 12. The B counter provided in the control means 11 starts counting from the measurable p point and measures the traveling distance. After the car approaches the first road shoulder reflector and the detection distance becomes smaller,
The next road shoulder reflector is detected at point a, and the sudden increase detection means 11a
Detects a sudden increase in the detection distance.

When the detection distance at the point a sharply increases, it is predicted that it may be detected by the road shoulder reflector, and the travel distance measuring means 11b (counter A) after the sudden increase operates from the point a to measure the travel distance of the automobile. To do. Then, before the traveling distance reaches the set value R set a little larger than the disposition distance based on the disposition distance of the road shoulder reflector, the sudden increase in the next detection distance is detected by the sudden increase detection means 11a at the point b. Then, the travel distance measuring means 11b after the sudden increase operates again to newly measure the travel distance of the vehicle from the point b. That is, the A counter indicating the traveling distance is reset once and then restarted to count the traveling distance from the sudden increase point. Due to the sudden increase in the detected distance for the second time, the alarm operation signal generated up to that point is stopped by the operation of the alarm control means 11d.

Thereafter, a similar detection state continues during traveling on a curve, and a rapid increase in the detection distance is detected one by one before reaching the set value R at point c, etc., and as long as the distance detection by the road shoulder reflector continues, the vehicle travels. The distance determination means 11c does not generate the set value excess signal, and therefore the alarm control means 11d does not release the prohibition of the alarm operation signal. If the next detection distance does not suddenly increase even after traveling the set value R, it is assumed that the vehicle has passed through the area of the shoulder reflector, and the alarm control means 11d does not prohibit the generation of the alarm operation signal. An alarm signal is generated from the means 12. If the detected distance measured by the distance measuring means 10 at this time is equal to or greater than the safe inter-vehicle distance Dr, of course, no alarm operation signal is generated.

Further, even when the detected distance is not traveling the set value R, the prohibition of the alarm operation signal is released and the alarm operation signal is generated when the front object is too close. In FIG. 2, when a sudden increase occurs at point c, the detection distance X immediately before that is stored, and a constant value from this X, for example, 20
The distance obtained by subtracting m is calculated and stored. And d
If the detected distance at the point is less than this distance "X-20" m, even if the vehicle has not traveled to the set value R, the alarm control means 11d acts to cause the alarm operation signal The prohibition is not performed, the prohibition is released and the alarm means 1
An alarm signal is generated from 2. According to this embodiment, since the conventional stationary object discriminating means is not provided, the configuration is simplified, and the warning is immediately prohibited when a sudden increase in the detection distance is detected, so the traveling distance is counted. There is no need, and alarm prohibition operation becomes faster. Next, FIG. 3 and FIG.
The operation of the control means 11 will be described in detail with reference to the flowchart of FIG.

In step 20, the initial setting is performed and the A counter and the B counter for counting the traveling distance are each set to 5
1 m, data α and β representing the detection distance are set to 99 m, which is almost the maximum detection distance, and the A flag is set to “0” and the alarm prohibition flag is set to “0”. .. Next, in step 21, the detection distance D _n , which is the distance between the vehicle and the distance measuring object in front, is measured. In step 22, this detection distance D _n is measured.
Is not measured. If the measurement is possible, in step 23, the detection distance D _n , which is the current measurement value, is set in α, and the previous α is set in β. At first, since there is no previous α, β is set to 99m.

Next, at step 24, it is judged whether or not the detection of the detected distance is started, that is, whether or not the distance measurement cannot be performed last time and the distance measurement can be performed this time. At first, it is the first time that distance measurement is possible, so proceed to step 25.
The B counter set to 1 m is reset to 0 m. Then, the process proceeds to the next step 26. When it is determined in step 24 that distance measurement is possible twice, the process directly proceeds to step 26 without passing through step 25. In this step 26, it is determined whether or not the difference between the present detection distance Dn α and the previous detection distance D _n−1 β is a predetermined value (for example, 5 m) or more. That is, it is determined whether or not there is a sharp increase in the detection distance.

The distance detection of the front object by the distance measuring means 10 is performed by periodically sampling the data,
The sampling period is, for example, 36 milliseconds. Distance detection is performed every 0.1 millisecond, and the detected values of 10 times are averaged in hardware and taken in every 1 millisecond.
The average of 6 times is used as the sampling value of the detection distance. The above detection distances D _n-1 and Dn are sampling values.
When it is determined in step 26 that the first detected distance has rapidly increased, as shown in point a in FIG. 2, at step 27, the distance immediately before the sudden increase is stored, which is the previously detected distance D _n-1 . β is set as the data X (distance immediately before the rapid increase), "X-20" m is calculated in the next step 28, and this data is stored in the memory. The distance of 20 m is a distance arbitrarily set according to safety.

Next, at step 29, it is judged whether or not there is a sudden increase in the detection distance for the second time. Since only one rapid increase is detected at point a, it is determined to be "NO" and the A flag is set to "1" in step 30. Further, in step 32, the A counter is reset to 0 m. Here, as shown at point b in FIG. 2, when it is determined that the detection distance has rapidly increased for the second time, it is determined to be “YES” in step 29 and the process proceeds to step 31, where an alarm prohibition signal is generated. The alarm prohibition flag is set to "1". next,
In step 33, it is judged whether or not the alarm prohibition signal is generated (whether or not the alarm prohibition flag is "1"). Since the alarm prohibition signal has already been generated in step 31, the process proceeds to step 34. ..

In step 34, it is judged whether or not the traveling distance after the sudden increase of the distance, that is, the count value of the A counter generated after the sudden increase of the distance exceeds 50 m. The distance of 50 m is a predetermined distance set to a value larger than the normal distance between the shoulder reflectors. In step 34, while the traveling distance after the counter is reset has not reached 50 m, the flow proceeds to step 35, where it is determined whether or not the detected distance α this time is greater than the predetermined distance 11 m (point e in FIG. 2). If it is determined that it is larger, the process proceeds to step 36.
In step 36, the detected distance α this time is the data “X-20” m (d in FIG. 2) stored in step 28.
Point) It is determined whether or not it is larger. If it is larger, the process proceeds to the next step 37.

When it is determined in step 34 that the count value of the A counter exceeds 50 m, it is determined that the vehicle has passed through the region of the road shoulder reflector, and the flow advances to step 44 to release the alarm prohibition signal and issue an alarm. The prohibition flag is set to "0". Next, at step 45, the A flag is set to "0" in order to reset the second rapid increase detection. Further, when the detection distance α becomes smaller than 11 m in step 35 and when the detection distance α becomes smaller than “X-20” m in step 36, the distance to the front detected object is too close. In either case, the flow proceeds to step 44 to release the alarm prohibition signal. Here, the reason why step 35 is provided is that the determination in step 36 includes the detection distance X immediately before the sudden increase, and since this value fluctuates, "X-20" m is an absolute approach safety distance. Since it does not exist, the step 35 of the fixed approach safety distance is supplementarily added.

If it is determined in step 33 that the alarm prohibition signal has not been generated, step 37 is performed as it is.
Proceed to. In step 37, it is judged whether or not the detected distance D _n is smaller than the safe inter-vehicle distance Dr, and if it is smaller, the routine proceeds to step 38, where it is judged whether or not an alarm prohibition signal is generated. If the alarm signal has already been generated in step 38 and the alarm prohibition flag is "1", step 39
And the generation of the alarm operation signal is stopped. After that, the flow returns to step 21, and the above operation is repeated. Then, if it is determined in step 38 that the alarm prohibition flag is "0", an alarm operation signal is generated in step 40. If it is determined in step 37 that the detected distance D _n is greater than the safe inter-vehicle distance Dr, there is no need for an alarm anymore, and the flow proceeds directly to step 39.

When it is determined in step 22 that the measurement of the detected distance D _n is impossible, it is determined in step 41 whether or not the vehicle has traveled a predetermined distance after the distance measurement becomes possible. That is, the count value of the B counter reset when the distance measurement becomes possible in step 25 is 50 m.
It is determined whether or not When the measurement is impossible from the beginning, the B counter is initially set to 51 m, so it is larger than 50 m, and the routine proceeds to step 42. If the B counter is reset to 0 m in step 25, "NO" is determined and the process proceeds to step 33 from this point until the vehicle travels 50 m. After traveling 50 m, the routine proceeds to step 42, where it is judged whether or not the distance has increased sharply, that is, whether or not the A flag is "0". If there is no sudden increase, the process proceeds to 43, and if there is a sudden increase, the process proceeds to step 33. In step 43, α and β are set to 99 m, respectively. When the measurement cannot be performed from the beginning, α and β are initially set to 99 m and therefore remain unchanged.

The reason why α and β are set to 99 m in step 43 is as follows. (A) of FIG.
As shown in, the detection distance decreases from the detectable point p,
If the distance decreases once and the distance cannot be measured at p'point after the sharp increase in distance is detected at p "point, the distance increases sharply due to the difference from p'point when the distance is detected at q point. Detected, but this is probably a shoulder reflector, so there is no problem.
As shown in (b), when the detection distance decreases from the detectable p point and measurement becomes impossible at the p'point without a sudden increase, when the distance detection at the q point after the predetermined time is performed, Although the road shoulder reflector is not detected, a sharp increase in distance may be detected due to the difference from p '. Therefore, if the detection distances α and β are set to 99 m when the B counter has traveled 50 m, the difference between this point r (99 m) and the q point does not cause a sharp increase in the distance, so the q point is It is no longer detected as a sudden increase in distance. After step 43, the flow proceeds to step 33.

[0025]

As described above, according to the present invention, since the conventional stationary object discriminating means is not provided, the structure is simplified, and when a rapid increase in the detection distance is detected twice, an alarm is issued immediately. Since the prohibition is performed, it is not necessary to count the traveling distance for a long time, and the alarm prohibition operation becomes faster. In addition, the warning prohibition is automatically canceled if the vehicle travels for a predetermined distance without detecting the next sudden increase, and the warning prohibition is also automatically canceled when the vehicle approaches a predetermined distance before traveling for a predetermined distance. You can secure enough. Therefore, while ensuring the safety by the warning signal, there is an excellent effect that the trouble of detecting the shoulder reflectors and continuously sounding the warning signal when traveling on a curve is eliminated.

[Brief description of drawings]

FIG. 1 is a block circuit configuration diagram showing an embodiment of the present invention.

FIG. 2 is a waveform diagram showing a relationship between a traveling distance of an automobile and a detection distance measured by distance measuring means in an embodiment of the present invention.

FIG. 3 is a flowchart showing the processing of the control means in FIG.

FIG. 4 is a flowchart showing the processing of the control means of FIG.

5 is a flow chart of steps 41 and 42 of the flowchart of FIG.
FIG. 43 is a waveform chart for explaining 43.

FIG. 6 is a plan view showing how an automobile detects a roadside reflector while traveling on a curve.

FIG. 7 is a waveform diagram showing a waveform of a detection signal of a roadside reflector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 automobile 2 road 3 shoulder reflector 4 beam 10 distance measuring means 11 control means 11a sudden increase detection means 11b traveling distance measuring means after sudden increase 11c traveling distance determination means 11d alarm control means 12 warning means 13 traveling detection means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Makoto Yamanoi 500 Kitawaki Shimizu City, Shizuoka Prefecture Koito Manufacturing Shizuoka Factory (72) Inventor Michio Arai 500 Kitawaki Shimizu City, Shizuoka Prefecture Koito Manufacturing Shizuoka Factory ( 72) Inventor, Yasushi Kubota, 500, Kitawaki, Shimizu, Shizuoka, Kozu Manufacturing Co., Ltd., Shizuoka Plant (72) Inventor, Riji Yanagisawa, 500, Kitawaki, Shimizu, Shizuoka Koito Manufacturing, Shizuoka, Ltd.

Claims (1)

[Claims] 1. A distance measuring means for measuring a distance from a vehicle to an object ahead of the vehicle, and an alarm means for issuing an alarm when the distance to the object measured by the distance measuring means is equal to or less than a predetermined safe inter-vehicle distance. In the reflector detection device, the mileage measuring means for measuring the mileage of the vehicle, and the sudden increase detecting means for outputting a sudden increase signal when a rapid increase in the detected distance is detected by the signal from the distance measuring means, and the sudden increase detecting means are provided. The mileage signal after the rapid increase for measuring the mileage of the vehicle from the time when the sudden increase is detected by the signal of the rapid increase, and whether or not the mileage measured by the mileage after the rapid increase has reached a predetermined set value is determined. When the set value exceeds the set value, the running distance judgment means is output, and the warning means is driven when the distance to the object measured by the distance measuring means is less than the safe inter-vehicle distance. If an alarm operation signal is generated and an alarm operation signal is generated when the sudden increase detection means generates the next sudden increase signal at a point before the mileage of the vehicle reaches the set value in the traveling distance determination means, the occurrence of the alarm operation signal is generated. A distance obtained by subtracting a predetermined distance from the detection distance immediately before the sudden increase when the distance to the object is detected and a sudden increase in the detection distance is detected. A reflector detection device, further comprising alarm control means for canceling the prohibition when the following occurs.