Obstacle warning method

Abstract

The present invention discloses an obstacle warning method, which includes the following steps: providing a photographic device with a first objective lens system and a second objective lens system, where the first objective lens system has a small depth of field fL, and the second objective lens system has a large depth of field fS; forming a large-aperture image under the first objective lens system and a small-aperture image under the second objective lens system; an obstacle is clear in the large-aperture image within the small depth of field fL; an obstacle is clear in the small-aperture image within the large depth of field fS; the large-aperture image and the small-aperture image are both blurred except for the above situations; comparing the contrast of the simultaneously obtained small-aperture image and large-aperture image to form a digital signal "0" or "1"; giving a safety indication, a warning indication or an emergency indication for the change of the digital signal twice in a row. The present invention can indicate whether an obstacle is outside the safe distance only by comparing the contrast of the large-aperture image and the small-aperture image, has strong practicability and is suitable for wide promotion and use.

Description

Technical Field

[0001] The present invention relates to a method for warning of obstacles, and particularly to an obstacle warning method capable of detecting the position of an obstacle by comparing the contrast of images. Background Art

[0002] In existing systems for autonomous driving on a driving surface, sensors etc. are used to detect obstacles and control the actions. For example, in vehicles such as cars, as a system to assist the driver, a contact avoidance assist device for a vehicle that assists in avoiding contact with obstacles has been developed (such as Patent Document: Japanese Patent Laid-Open No. 2008-49932). In addition, a method has been proposed in which a mobile robot is moved in a direction indicated by remote control operation, and the moving speed is calculated based on the distance from the obstacle detected by the sensor, thereby preventing contact with the obstacle (such as Patent Document: Japanese Patent Laid-Open No. 2006-285548). At the same time, with the continuous progress of technology, recently, the following measurement technology has been adopted as a powerful means: using a camera etc. mounted on a car to photograph an external object scene, performing image processing on the photographed image, and obtaining the distance from the car to the object (such as, Patent Document: Japanese Patent Laid-Open No. 5-114099). This image-based distance measurement technology is generally classified into the following technologies: a technology for estimating the distance to an object using the relationship with the camera position based on a monocular visible image; and a technology for obtaining the distance to an object using the principle of triangulation based on multiple images taken by multiple cameras. Among them, the measurement technology for obtaining the distance using the principle of triangulation based on multiple images obtains the distance based on the relative offset of the positions of the same object in the left and right images, so an accurate distance can be obtained.

[0003] All of the above-mentioned existing obstacle detection methods need to be completed by means of the calculation of an intelligent computer. Based on this, the inventors of the present application, through a large amount of understanding of the prior art, proposed an innovative obstacle warning method that can indicate whether an obstacle is within a safe distance only by comparing the contrast of images.

[0004] Therefore, there is an urgent need for an obstacle warning method different from the past. Summary of the Invention

[0005] The object of the present invention is to provide an obstacle warning method that can know the position of an obstacle by comparing the contrast of pictures.

[0006] The obstacle warning method provided by the present invention includes the following steps:

[0007] Provided is a photographic device having a first objective lens system and a second objective lens system. The first objective lens system has a small depth of field fL, and the second objective lens system has a large depth of field fS. For the same obstacle, the range of the small depth of field fL is located within the range of the large depth of field fS;

[0008] Obtained for the same position and the same time of the same obstacle, a large-aperture image formed under the first objective lens system and a small-aperture image formed under the second objective lens system;

[0009] The large-aperture image of the obstacle is clear within the range of the small depth of field fL; the small-aperture image of the obstacle is clear within the range of the large depth of field fS; the large-aperture image and the small-aperture image of the obstacle are both blurred except for the above situations;

[0010] Compare the contrast of the simultaneously obtained small-aperture image and large-aperture image. Assign the digital signal "0" to the contrast comparison result of the small-aperture image and the large-aperture image that are both clear, assign the digital signal "1" to the contrast comparison result of the clear small-aperture image and the blurred large-aperture image, and assign the digital signal "0" to the contrast comparison result of the small-aperture image and the large-aperture image that are both blurred; and

[0011] Receive the digital signal, give a safety indication for two consecutive digital signal changes of "0""0", give a warning indication for two consecutive digital signal changes of "0""1", and give an emergency indication for two consecutive digital signal changes of "1""0".

[0012] Compared with the prior art, the optical image of the obstacle forms a large-aperture image through the first objective lens system, and the optical image of the obstacle forms a small-aperture image through the second objective lens system. By comparing the contrast of the large-aperture image and the small-aperture image obtained simultaneously at the same position and the same time of the obstacle and assigning a digital signal to the comparison result, and giving one of the three indications of a safety indication, a warning indication, or an emergency indication according to the change of two consecutive digital signals, thereby obtaining a prompt whether the obstacle is outside the safe distance. As can be seen from the above, the present invention does not require complex calculations by an intelligent computer, and only by comparing the contrast of the large-aperture image and the small-aperture image can it prompt whether the obstacle is outside the safe distance. Obtaining the large-aperture image and the small-aperture image can be completed only through optical devices. Therefore, the obstacle warning method of the present invention has a different obstacle detection method from the past, has strong practicability, and is suitable for wide promotion and use.

[0013] Preferably, the aperture diameter of the first objective lens system is larger than the aperture diameter of the second objective lens system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1It is a corresponding schematic diagram of a large-aperture image and a small-aperture image when an obstacle is located at different positions, and a schematic diagram of the comparison result of the image contrast between the two. Detailed implementation mode

[0015] Now, embodiments of the present invention will be described with reference to the accompanying drawings, in which like reference numerals represent like elements.

[0016] The obstacle warning method provided by the present invention includes the following steps: providing a photographic device having a first objective lens system and a second objective lens system, the first objective lens system having a small depth of field fL, and the second objective lens system having a large depth of field fS, and the range of the small depth of field fL of the same obstacle is located within the range of the large depth of field fS; specifically, the first objective lens system and the second objective lens system are composed of existing convex lens assemblies, apertures, plane mirror assemblies and CCD pick-up devices; more specifically, the aperture diameter of the first objective lens system is larger than that of the second objective lens system, and the first objective lens system and the second objective lens system share the same CCD pick-up device, and the first objective lens system and the second objective lens system are exactly the same except for the different aperture diameters; this is more convenient for large-scale production and manufacturing. Obtain at the same position and the same time of the same obstacle, and form a large-aperture image under the first objective lens system and a small-aperture image under the second objective lens system. When the obstacle is within the range of the small depth of field fL, the large-aperture image is clear; when the obstacle is within the range of the large depth of field fS, the small-aperture image is clear; when the obstacle is outside the above situations, both the large-aperture image and the small-aperture image are blurred; since the range of the small depth of field fL of the same obstacle is located within the range of the large depth of field fS, the small-aperture image of the obstacle within the range of the small depth of field fL must be clear. Compare the contrast of the simultaneously obtained small-aperture image and large-aperture image, and assign the digital signal "0" to the contrast result of the small-aperture image and the large-aperture image that are both clear, assign the digital signal "1" to the contrast result of the clear small-aperture image and the blurred large-aperture image, and assign the digital signal "0" to the contrast result of the small-aperture image and the large-aperture image that are both blurred. Receive the digital signal, issue a safety indication for the change of the digital signal twice in a row as "0""0", issue a warning indication for the change of the digital signal twice in a row as "0""1", and issue an emergency indication for the change of the digital signal twice in a row as "1""0". Specifically, in combination with Figure 1As shown in the figure, the large-aperture image and the small-aperture image in the figure are indicated by dotted lines as blurred images, by solid lines as clear images, by rectangular bars at high positions as digital signal "1", and by rectangular bars at low positions as digital signal "0". In the present invention, the comparison result formed by comparing the contrast of the large-aperture image and the small-aperture image is that, when comparing the difference in the contrast of the large-aperture image and the small-aperture image, when both the large-aperture image and the small-aperture image are blurred, their contrasts are approximate, and the difference can be represented by the digital signal "0"; when one of the large-aperture image and the small-aperture image is blurred and the other is clear, the contrast difference between the two is large, and the difference can be represented by the digital signal "1"; when both the large-aperture image and the small-aperture image are clear, their contrasts are approximate, and the difference can be represented by the digital signal "0". Since the first objective lens system has a small depth of field fL, the second objective lens system has a large depth of field fS, and the range of the small depth of field fL of the same obstacle is within the range of the large depth of field fS; therefore, based on the existing optical principles and combined with Figure 1It can be known that: (1) When the obstacle is located outside the large depth of field fS, the small-aperture image and the large-aperture image formed for the same obstacle at the same position and at the same time are both blurred, and the contrast of the two images is approximate; (2) When the obstacle is located within the large depth of field fS and outside the small depth of field fL, the small-aperture image formed for the same obstacle at the same position and at the same time is clear while the large-aperture image is blurred, and the contrast difference between the two images is obvious; (3) When the obstacle is located within the small depth of field fL (since the obstacle is located within the small depth of field fL, it must also be located within the large depth of field fS), the small-aperture image and the large-aperture image formed for the same obstacle at the same position and at the same time are both clear, and the contrast of the two images is approximate. Compare the contrast of the large-aperture image and the small-aperture image obtained simultaneously for the same obstacle at the same position and at the same time. When the contrast of the small-aperture image and the large-aperture image is approximate, the contrast comparison result is assigned the digital signal "0"; when the contrast difference between the small-aperture image and the large-aperture image is obvious, the contrast comparison result is assigned the digital signal "1"; issue a safety indication for two consecutive changes in the digital signal of "0" "0", issue a warning indication for two consecutive changes in the digital signal of "0" "1", and issue an emergency indication for two consecutive changes in the digital signal of "1" "0"; specifically, the above three indications include the meanings corresponding to the safety indication, warning indication, and emergency indication in the following (1)-(3) regarding whether the obstacle is outside the safe distance; specifically (in the following description, N is a natural number greater than or equal to 1): (1) The comparison result received for the Nth time is the digital signal "0", and the comparison result received for the N+1st time is the digital signal "0". Combining the relationship between the obstacle 100 and the depth of field indicated by the digital signals "0" and "0" in the above comparison results, it can be known that when the comparison result received for the Nth time is the digital signal "0", the obstacle is located outside the large depth of field fS, and when the comparison result received for the N+1st time is the digital signal "0", the obstacle continues to be located outside the large depth of field fS, indicating that the obstacle is far from the photographic device of the present invention. At this time, the two consecutive digital signal comparison results of "0" "0" correspond to the obstacle moving away from the photographic device, so a safety indication that the obstacle is always outside the safe distance is issued. At this time, if the present invention is applied to a vehicle or an aircraft, an operation of limiting or reducing the speed and avoiding will be performed on the vehicle or the aircraft.(2) The comparison result received for the (N + 1)-th time is the digital signal "0", and the comparison result received for the (N + 2)-th time is the digital signal "1". Considering the relationship between the obstacle 100 and the depth of field indicated by the digital signals "0" and "1" in the above comparison results, when the comparison result received for the (N + 1)-th time is the digital signal "0", the obstacle is outside the large depth of field fS. When the comparison result received for the (N + 2)-th time is the digital signal "1", the obstacle changes from outside the large depth of field fS to inside the large depth of field fS, indicating that the obstacle is approaching the photographic device of the present invention. At this time, the continuous change of the two digital signal comparison results "0" "1" corresponds to the obstacle gradually approaching the photographic device and still having a certain distance from the lens, thus issuing a warning indication that the obstacle is getting closer. At this time, if the present invention is applied to a vehicle or an aircraft, an operation of speed limit or deceleration and avoidance will be implemented on the vehicle or the aircraft. (3) The comparison result received for the (N + 2)-th time is the digital signal "1", and the comparison result received for the (N + 3)-th time is the digital signal "0". Considering the relationship between the obstacle and the depth of field indicated by the digital signals "0" and "1" in the above comparison results, when the comparison result received for the (N + 2)-th time is the digital signal "1", the obstacle 100 is inside the large depth of field fS and outside the small depth of field fL. When the comparison result received for the (N + 3)-th time is the digital signal "0", the obstacle changes from inside the large depth of field fS to inside the small depth of field fL, indicating that the obstacle 100 is gradually approaching and approaching the photographic device. At this time, the continuous change of the two digital signal comparison results "1" "0" corresponds to the obstacle approaching the photographic device and about to collide, thus issuing an emergency indication of about to collide with the obstacle. At this time, if the present invention is applied to a vehicle or an aircraft, an operation of acceleration or maintaining the current state will be implemented on the vehicle or the aircraft.

[0017] As Figure 1 shown, the optical image of the obstacle 100 forms a large-aperture image through the first objective lens system, and the optical image of the obstacle forms a small-aperture image through the second objective lens system. By comparing the contrast of the large-aperture image and the small-aperture image obtained simultaneously at the same position and the same time of the same obstacle 100 and assigning a digital signal to the comparison result, and based on the change of the continuous two digital signals, one of the three indications of safety indication, warning indication or emergency indication is issued, so as to obtain a prompt whether the obstacle is outside the safe distance. As can be seen from the above, the present invention does not need to rely on the complex calculations of an intelligent computer. Only by comparing the contrast of the large-aperture image and the small-aperture image can it be prompted whether the obstacle is outside the safe distance. Obtaining the large-aperture image and the small-aperture image can be completed only through optical devices. Therefore, the obstacle warning method of the present invention has an obstacle detection method different from the past, with strong practicability and is suitable for wide promotion and use.

[0018] In addition, the comparison principle and working mode of the contrast between the two images involved in the present invention are well known to those of ordinary skill in the art, and no detailed description will be given here.

[0019] The above-disclosed are only the preferred embodiments of the present invention. Of course, the scope of the rights of the present invention cannot be limited thereby. Therefore, equivalent changes made according to the scope of the patent application of the present invention still fall within the scope covered by the present invention.

Claims

1. An obstacle warning method, characterized in that, The method includes the following steps: Provide a photographic device having a first objective lens system and a second objective lens system. The first objective lens system has a small depth of field fL, and the second objective lens system has a large depth of field fS. For the same obstacle, the range of the small depth of field fL is located within the range of the large depth of field fS; Acquire, at the same position and the same time of the same obstacle, a large-aperture image formed under the first objective lens system and a small-aperture image formed under the second objective lens system; The large-aperture image of the obstacle is clear within the range of the small depth of field fL; the small-aperture image of the obstacle is clear within the range of the large depth of field fS; the large-aperture image and the small-aperture image of the obstacle are both blurred except for the above situations; Compare the contrast of the simultaneously acquired small-aperture image and large-aperture image. Assign the digital signal "0" to the contrast comparison result of the small-aperture image and the large-aperture image that are both clear, assign the digital signal "1" to the contrast comparison result of the clear small-aperture image and the blurred large-aperture image, and assign the digital signal "0" to the contrast comparison result of the small-aperture image and the large-aperture image that are both blurred; and Receive the digital signal, issue a safety indication for two consecutive digital signal changes of "0""0", issue a warning indication for two consecutive digital signal changes of "0""1", and issue an emergency indication for two consecutive digital signal changes of "1""0".

2. The obstacle warning method according to claim 1, wherein The aperture diameter of the first objective lens system is larger than the aperture diameter of the second objective lens system.

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