JPH08177263A - Method for detecting opening or closing of car door - Google Patents

Abstract

PURPOSE: To automatically detect the opened or closed state of car doors, by carrying out a binary operation of the difference against two kinds of images at the time of irradiation and non-irradiation of infrared zone laser beam. CONSTITUTION: A cylindrical lens 4 and a shutter 5 are fitted to the front face of laser beam source 3 of the infrared zone and the laser beam is given off to horizontally radiate a belt-form projective beam on the irradiation face 6 including the front door 1 and the rear door 2 of a car. The shutter 5 is controlled by an image processor 9 and turned on and off at every certain interval. A binarizing operation of the difference is carried out against the two images at the time of irradiation when the doors are photographed by a CCD camera 8 through a filter 7 or non-irradiation to extract a projected profile. The distance and angle of the projected profile of the front and rear door positions are operated by an image processor 9, on the binarized image or the difference obtained in such a way. In this way, the opened extent of the doors 1, 2 can be estimated. When the shortest distance and/or angle exceeds a certain threshold, it is discriminated that the door is half-closed and an alarm is given to prevent the car with half-opened doors from driving in.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle door open / close detection method for automatically detecting the open / closed state of a vehicle door.

[0002]

2. Description of the Related Art In a mechanical parking lot, when a car is loaded with a half-door or an open door, transportation, storage,
In the process of leaving the warehouse, the door may come into contact with mechanical equipment and cause damage to the car. As a method of automatically detecting the open / closed state of the door, a method of utilizing a reflected wave from the door opening by ultrasonic waves and a method of processing a car image can be considered.

In such a method, the target vehicle is used in various types and various sizes, shapes, and coating states, and there are variations in the position angle and the like when the vehicle is stopped at the entrance. Therefore, in the case of ultrasonic waves, the sensor cannot always be fixed at an appropriate position due to the directivity of the sound, and the image processing makes the image complicated and the opening state cannot be extracted.
Even if it is possible, the door open / closed state sensing has not been put into practical use due to the fact that the processing takes an enormous amount of time and the equipment becomes large.

As another example, there has been proposed a method of detecting a half-door state of a vehicle by a plurality of photoelectric sensors (Japanese Patent Laid-Open No. 10635/1993). In this method, since the optical axis of the photoelectric sensor is fixed, it is possible to correct the relative positional relationship between the door and the optical axis due to changes in the width of the vehicle, displacement of the vehicle placed on the lifting device, etc. In particular, in a car with a narrow vehicle width, it cannot be detected unless the opening amount of the door is large, and it is not possible to determine the door opening in a small semi-door state.

[0005]

As described above, in the mechanical parking lot, if the open / closed state of the vehicle door can be automatically detected, the damage trouble of the vehicle can be greatly reduced, and safety or equipment Great operational advantages can be obtained. The present invention has been made in view of the above-mentioned prior art, and provides a device provided with a means for automatically detecting an open / closed state of a car door at an entrance of a mechanical parking lot at low cost. To aim.

[0006]

The structure of the present invention for solving the above-mentioned problems is to irradiate a horizontal band-shaped infrared laser beam intermittently to a range including a vehicle body door, and when irradiating in the range. Two types of images during non-irradiation are photographed by a CCD camera, and a difference binarization operation is performed on the two photographed images to extract the projected contour of the laser light, and the car door is extracted from the projected contour. The open / closed state of is determined. Here, the open / closed state of the car door can be determined from the size of the inclination and distance of the projected contour cut / separated by the opening of the car door.

[0007]

[Function] By using the infrared laser as the band-shaped projection light projected on the vehicle body, it is possible to reduce the influence of unevenness of the paint color, characters such as characters and patterns on the vehicle body, and uneven brightness. Since there are few components, the effect of changes in sunshine conditions can be reduced.

Further, the infrared laser is intermittently irradiated,
By extracting the projected contour by applying the difference calculation to the image during irradiation and non-irradiation, further painting,
The effect of the image in the field of view of the car and its surroundings,
Disturbance can be eliminated, and the contour of only the projection light can be extracted. Furthermore, if the door is open, the projected contour is cut / separated at that part, and the larger the opening amount, the larger the interval or (and) distance between the separated lights. The degree of the door opening can be identified by the angle and distance of the obtained light pattern.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the drawings. One embodiment of the present invention is shown in FIG. As shown in the figure, the laser light source 3 and the CCD camera 8 are installed at the entrance of the mechanical parking lot. The laser light source 3 is arranged toward the car into which the car is stored, and the CCD camera 8 is arranged so that the irradiation surface 6 of the car is the field of view.

A cylindrical lens 4 and a shutter 5 are attached to the front surface of the laser light source 3, and when laser light is emitted from the laser light source 3, the laser light passes through the cylindrical lens 4 and the shutter 5 to form a horizontal strip shape. The projection light is applied to the irradiation surface 6 including the front door 1 and the rear door 2 of the vehicle.

Here, as the laser light source 3, an infrared laser, for example, a laser diode having a wavelength of 780 nm is used. By using infrared light, it is possible to reduce the effects of unevenness in color and brightness such as paint colors, car body characters, patterns, etc.
Further, since the wavelength component of sunlight is small, the influence of changes in sunshine conditions can be reduced.

The shutter 5 is controlled by the image processing device 9 and is turned on and off at regular intervals to shield the laser light from the laser light source 3. Therefore, the irradiation surface 6 is intermittently irradiated with the laser light. CCD camera 8
Filter 7 is attached to the front of the
The image captured by the CCD camera 8 is subjected to image processing by the image processing device 9.

As the filter 7, it is preferable to use a filter that selectively passes the wavelength of the laser light source 3 because the influence of external light can be reduced. In the image processing device 9, the difference binarization processing operation is performed on the two images taken by the CCD camera 8 at the time of irradiation and at the time of non-irradiation, and the projected contour is extracted. Further, the image processing device 9 has a function of determining the open / closed state of the door based on the angle of the projected contours separated by the opening of the door and / or the size of the distance.

That is, by binarizing the region where the difference in light amount of the difference image is large to some extent, a strip-shaped projected contour in the horizontal direction of the door height can be obtained. As shown in FIG. 2, on the differential binarized image, the area a is the projected contour of the front door 1, the area b is the projected contour of the rear door 2, and the shortest distance δ between these areas a and b is the front door. If the front door 1 is open, the angle θ formed by the long axes of the regions a and b is increased if the front door 1 is open. On the contrary, if the front door 1 is closed, the region a and the region b are almost continuous, the shortest distance δ is almost 0, and the angle θ formed by the major axes of the regions a and b is also close to 0.

The image processing device 9 calculates the distance and angle of the projected contours of the portions where the front door 1 and the rear door 2 are located on the thus-obtained differential binarized image.
When the shortest distance δ or (and) the angle θ exceeds a certain threshold, it is judged that the door is in a half-door state, and an alarm is issued, or the operation of the warehousing device is stopped. It is possible to prevent warehousing in the state.
Further, on the differential binarized image shown in FIG. 2, the region b is the projected contour of the rear door, the region c is the projected contour of the rear panel,
The opening amount of the rear door 2 can be determined in the same manner from the shortest distance between the regions b and c or (and) the angle formed by the optical axes.

Therefore, in order to carry out the method for detecting the opening / closing of the vehicle door in this embodiment, first, the shutter 5 is closed to project the image of the projection light when not illuminated (hereinafter referred to as the first image). CCD camera 8
And then the shutter 5 is opened to capture an image of the projection light at the time of irradiation (hereinafter referred to as the second image), and subsequently, the image processing apparatus 9 performs a difference binarization calculation process between the first image and the second image. The projected contour is extracted by performing the above, and the amount of deviation between the cut / separated length and angle of the projected contour is calculated as described above to determine whether or not the door is in the half-door state.

According to the measuring method of the present embodiment, it is necessary that the direction and direction of the vehicle be substantially constant at the entrance, regardless of slight differences in vehicle dimensions and variations in stop positions in the mechanical parking lot. The open state of the door can be reliably determined. The half-door state described in this embodiment means all states in which the door is not completely closed.

[0018]

As described above with reference to the embodiments, according to the present invention, since the open / closed state of the vehicle door can be determined by an extremely simple method using one light source and one camera, it is possible to reduce the speed at a high speed. It is possible to provide a costly door open / close detection device, and by installing it at the entrance of a mechanical parking lot, it is possible to obtain a great advantage in terms of operation and safety that a fatal trouble such as a car damage can be prevented.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a vehicle door open / closed detection method according to an embodiment of the present invention.

FIG. 2 is a flowchart showing image processing processing.

[Explanation of symbols]

 1 Front Door 2 Rear Door 3 Laser Light Source 4 Cylindrical Lens 5 Shutter 6 Sheet Light Source Irradiation Surface 7 Filter 8 CCD Camera 9 Image Processing Device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G06T 7/00

Claims (2)

[Claims] 1. A horizontal band-shaped infrared laser beam is intermittently irradiated to a range including a vehicle body door, and two kinds of images in the range, i.e. irradiated and non-irradiated, are photographed by a CCD camera, Opening and closing a car door characterized by extracting a projected contour of the laser light by performing a difference binarization operation on the two captured images and determining an open / closed state of the car door from the projected contour. Detection method. 2. The opening / closing state of the vehicle door according to claim 1, wherein the opening / closing state of the vehicle door is determined from the size of the inclination and the distance of the projected contour cut / separated by the opening portion of the vehicle door. Detection method.