JPH0752094B2 - Inventory detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a device for measuring an inventory quantity of powders, granules, etc., which are put into a hopper, and particularly to a level of a waste input hopper in an urban refuse incinerator. The present invention relates to an inventory amount detection device suitable when it is difficult to directly measure the inventory amount by a meter or the like.

[Prior Art] Conventionally, there are a level meter method and a load cell method as a method for directly measuring the inventory quantity of objects in a hopper. The level meter method measures the distance to the surface of the object in the hopper by static electricity or ultrasonic waves, and calculates the inventory quantity based on the value (for example, Japanese Patent Publication No. 61-42690). In the load cell system, the weight including the hopper is directly measured by the load cell, and the weight (constant) of the hopper is subtracted from the value to obtain the stock amount (for example, Japanese Patent Laid-Open No. 62-171827). Further, as an indirect measurement method, there is a method in which the particle size and the number of objects to be put into the hopper are measured from a still image with a television camera, and the stock amount is measured from the difference between the cut amount from the hopper (for example, Japanese Patent Publication No. 63-10058).

[Problems to be Solved by the Invention] However, in the level meter method, accurate inventory data cannot be obtained depending on the position measured by the sensor of the level meter when the upper surface of the object in the hopper on which the objects are accumulated has an inclination. There is. In addition, although an accurate inventory can be obtained with the load cell method, when installing the load cell, it may be difficult to install the load cell due to the mechanical structure of the hopper and the surrounding machines because the total weight of the hopper is received. . Further, when the diameter and the number of powder particles are measured with a television camera to determine the input amount, there is a drawback that the arithmetic unit is complicated and expensive.

[Means for Solving the Problems] The present invention takes in an image in a hopper by an image input device provided above a funnel-shaped hopper, processes image information by an image processing device, and detects the material in the hopper. In a stock quantity detection device for obtaining characteristic information on the stock quantity and calculating the stock quantity by the stock quantity calculation section from the characteristic information, the characteristic information is a plane image of the upper surface of the material, and the calculation of the stock quantity calculation section is stored in advance. It is characterized in that the calculation is performed based on the approximated formula of the two-dimensional image area-stock amount.

[Operation] The plane image area of the upper surface of the material in the hopper is determined by the shape of the hopper and the stock amount, but the stock amount and the plane image area are measured in advance, and an approximate expression based on the data is obtained. Next, the plane image area is calculated by the stock amount calculation unit based on the image information from the image input device, and the stock amount is obtained by the approximate expression.

[Embodiment] The embodiment of the present invention will be described.

FIG. 1 is a block diagram showing an embodiment of the present invention, in which a material 2 such as municipal waste put in a hopper 1 is cut out by a feeder 3 and sent to a next step 4 such as a next incinerator. An image input device 5 such as a television camera provided above the hopper 1 takes in a two-dimensional image in the hopper 1, processes the image information by an image processing device 6, and obtains characteristic information regarding the stock amount v of the material 2. As the characteristic information, an arbitrary reference point, for example, the distance from the edge of the hopper 1 to the edge of the material,
The planar image shape of the upper surface of the material, the peripheral distance of the planar image of the upper surface of the material, the planar image area of the upper surface of the material, etc. can be obtained. It was the most suitable. The inventory amount calculation unit 7 is a device that calculates the planar image area s of the upper surface of the material 2 as one of the characteristic information from the image processing device 6 and further calculates the inventory amount v. The relationship between the planar image area s and the stock amount v is determined by the shape of the hopper, but a function is obtained in advance as an approximate expression, v = f (s), based on the actual measurement data shown in FIG. .

The material 2 in the hopper 1 changes as shown in FIG. 3 depending on the amount of stock. That is, when the material 2 is put in, the inventory quantity v1 becomes almost full up to the upper surface of the hopper 1 as shown in FIG. 3 (a), and the image processing device 6 is shown in FIG. The planar image area s1 shown in () is input. Next, when the material 2 is cut out by the feeder 3 at the lower part of the hopper, the stock amount v is v2, v2 in FIG.
It changes from v3 in (c) and v4 in (d), and the planar image area is also the fourth
The s2 in FIG. 3 (b), the s3 in (c), and the s4 in (d) are changed, and the stock amount in the middle of the change is obtained by the stock amount calculation unit 7 from the approximate expression. It is detected that the stock amount has decreased to a certain amount in the state. When the stock quantity below a certain amount is reached, the next material 2 is charged.

EFFECTS OF THE INVENTION As described above, according to the present invention, the image information inside the hopper is input by the image input device provided above the hopper, and the information is processed to obtain the stock quantity of the material inside the hopper. Even if it is difficult to attach the hopper under the hopper like a load cell, it is possible to easily install the detector, and it is possible to provide a detection device that can accurately detect the stock amount.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the relationship between the stock amount and the area of a plane image, and FIGS. 3 (a), (b), (c), (d). ) Is an explanatory view showing a side cross section of the hopper 1, and FIGS. 4 (a), (b), (c), (d).
FIG. 3 is an explanatory view showing a plane of the hopper 1. 1 ... Hopper, 2 ... Material, 3 ... Feeder, 5 ...
Image input device, 6 ... Image processing device, 7 ... Inventory amount calculation unit

Claims (1)

[Claims] 1. An image input device provided above a funnel-shaped hopper is used to take in an image in the hopper, and image information is processed by an image processing device to obtain characteristic information concerning the stock amount of materials in the hopper, In a stock quantity detection device for calculating a stock quantity from a stock quantity calculation unit from the characteristic information, the feature information is a planar image of an upper surface of a material, and the calculation of the stock quantity calculation unit is a pre-stored plane image area-stock quantity An inventory amount detecting device characterized in that the calculation is based on the approximation formula of.