WO2013029268A1 - Method for measuring height of center of mass of object and measuring apparatus - Google Patents

Abstract

A method for measuring the height of the center of mass of an object and a measuring apparatus utilizing the measuring method. The measuring method comprises the following steps: (a) using a conveyor belt to form a first surface (11) and a second surface (12) intersecting at an inflection point (A); (b) while a bottom surface of the object is in contact with the conveyor belt and moves along with same, determining at a first moment of inflection a first vertical line (l₁) passing through the inflection point, and determining at a second moment of inflection a second vertical line (l₂) passing through the inflection point; and (c) acquiring a point of intersection (G), which is the center of mass, of the first vertical line (l₁) and the second vertical line (l₂).

Description

 Method for measuring body height and height and measuring device

 Technical field

 The present invention relates to a method for measuring the height of the center of gravity of an object, and more particularly to a method for measuring the non-contact of the height of the center of gravity of the object. The present invention also relates to an assay device using the above assay method. Background technique

 The position of the center of gravity of an object has an important influence on the transportation and use of the object. In particular, for a large object having a flat bottom structure such as a container, since its own volume and quality are large and it is not possible to actively move, it is more difficult to measure the center of gravity.

 At present, methods for determining the height of the center of gravity of an object include weighing method, suspension method, compound pendulum method, and platform weighing method. The above method is a well-known method in the art. For the sake of brevity, the above method is not described herein, and only the most commonly used suspension method and ground reaction method are described in detail. In Fig. 1 and Fig. 2, the conventional method is introduced by taking an object of a flat bottom structure as an example, but the method is not limited to an object of a flat bottom structure, and is applicable to objects of various shapes.

As shown in Figure 1 and Figure 2, first attach a rigid reticle on one side of the object; then measure the mass M of the object using the weighbridge; place the first end of the object on the weighbridge, and hang the sling at the second end Up, and the sling is perpendicular to the horizontal plane, the grounding point of the object is on the BB'line; the reaction force R of the grounding point on the weighbridge is measured; the horizontal distance between the sling and the grounding point of the object is determined. Calculate the horizontal distance C=Rd/M between the sling and the weight of the object; draw a vertical line of C from the sash fixed to the side of the object, the vertical line is passed a straight line of the weight of the object; then place the second end of the object on the weighbridge, the first end is lifted with a sling, and the sling is perpendicular to the horizontal plane, and the grounding point of the grounding end of the object is on the BB'line; The reaction force R' of the grounding point on the weighbridge; the horizontal distance between the sling and the object grounding point From d'_; the horizontal distance between the sling and the weight of the object is calculated by the torque formula C'=R'd'/M; the horizontal distance from the sling is drawn on the stencil fixed to the side of the object. C 'vertical line _12, the vertical line ₁₂ through another line that is a center of gravity; and the two vertical lines, and ^ is the intersection ₁₂ of the center of gravity, measured at the center of gravity from the floor object is on the ground The height is the height h of the object's center of gravity.

Note that the reticle should be large enough so that the vertical lines and ₁₂ can be extended in the reticle and intersect at a point.

 In addition, an auxiliary device can be placed on the weighbridge to limit the grounding point when the object is suspended, and to prevent the grounding end of the object from slipping during suspension, resulting in an error in the measurement result.

 There are many problems in determining the height of the body weight center by the above method.

 First, the above measurement method has certain risks. Since the above measurement process requires lifting one end of the object with a sling, it is easy to cause the object to roll sideways.

 Second, the above method is inefficient in measurement. There are many equipments required during the measurement process, and the process is complicated, including large equipment such as weighbridges and cranes. The measurement process lasts for a long time.

In addition, the most important thing is that the accuracy of the measurement results is difficult to control. Since the sling must be perpendicular to the horizontal plane during the measurement process, the grounding points at both ends of the object must be in a straight line (the BB' line in the figure), so repeated debugging is required, and it is difficult to meet the accuracy requirements. Moreover, the two vertical lines ^ and ^ which determine the center of gravity are manually drawn, so there is an artificial error. All of the above errors will directly affect and not only the measurement methods described in detail above, but the various methods in the prior art are mostly applicable to objects of lighter quality, and objects of large flat-bottom structures such as containers or large workpieces. The weight is usually much heavier, so some traditional methods of measuring the height of the body are not even usable. Moreover, although the height of the center of gravity of the object of the large flat-bottom structure can be measured by the above-described measuring method, the problem is more prominent. Summary of the invention

 SUMMARY OF THE INVENTION An object of the present invention is to provide a method for measuring the height of the center of gravity of an object which can more accurately find the center of gravity of the object by a simple and non-contact operation.

 In order to achieve the above object, the present invention provides a method for measuring the height of the center of gravity of an object, wherein the measuring method comprises the following steps:

 (a) forming a first plane and a second plane with a conveyor belt, the first plane and the second plane intersecting at the inflection point;

 (b) the bottom surface of the object is in contact with the conveyor belt and moves with the conveyor belt to determine the passage of the first turning moment of movement of the object from the first plane to the second plane past the inflection point Determining a first perpendicular of the inflection point, and determining a second perpendicular passing through the inflection point after the object moves from the second plane to the first plane through a second inversion moment;

 (c) obtaining an intersection of the first vertical line and the second perpendicular line as a center of gravity.

Preferably, the angle between the first plane and the horizontal plane is Θ the angle between the second plane and the horizontal plane is θ ₂ , wherein 9 i < 45 ° and θ ₂ < 45 °.

 Preferably, the first inversion moment and the second inversion moment are the starting moments of the object inversion process.

Preferably, in step (b), the object is at a bottom edge of a vertical section along the direction of the conveyor belt, the bottom edge is located on the conveyor belt, and the length of the bottom edge is L; a first inversion point on the bottom edge of the first inversion moment and a second inversion point on the bottom side of the second inversion moment; the first inversion point and the vertical direction The angle is a first straight line of the completion, and a second line passing the second inversion point and having an angle θ ₂ with the vertical direction, the first line and the second line respectively and the first line The vertical line corresponds to the second vertical line.

 Preferably, the first inversion point and the second inversion point are points respectively coincident with the inflection point on the bottom edge of the object at the first inversion moment and the second inversion moment.

Preferably, at the first starting moment, the object is located at a first starting position, and at the second starting moment, the object is located at a second starting position; recording the object at the first speed ^ from the first A starting position to the turning point and a first time ^ inversion occurs, and the object at a second speed V ₂ from the inflection point to the second starting position and overturn the second time t _2.

 Preferably, at the first starting moment, the object moves from the first plane toward the second plane with the conveyor belt; at the second starting moment, the object follows the conveyor belt The second plane moves toward the first plane.

Preferably, in the first starting position, a distance between the first end of the bottom edge away from the inflection point and the inflection point is L _{1 ;} in the second starting position, the bottom edge is far away The distance between the second end point of the inflection point and the inflection point is L ₂ .

Preferably, a distance between the first end point of the bottom edge of the object and the first flip point DFL-^X^; the second end point of the bottom edge of the object and the second The distance between the flip points is D ₂ = Lv ₂ X t ₃ .

Preferably, the center of gravity height H = (LD! - D ₂ ) / (tan Θ _{1 + t} an θ ₂ ).

Preferably, the first speed _V1 is equal to the second speed ν ₂ .

 Preferably, a pressure sensor is disposed under the conveyor belt at the inflection point, and the first inversion moment and the second inversion timing are determined according to a sudden change in the detected value of the pressure sensor.

Preferably, the pressure sensor is connected to a timer to control the timer to record the first time ^ and the second time t ₂ .

 Preferably, the vertical section of the object is obtained by an image capturing device, and the length of the bottom side of the vertical section is measured.

 Preferably, the image capturing device comprises a camera and a camera.

 Further, the present invention provides a measuring device for the height of the center of gravity of an object, wherein the measuring device comprises a conveyor belt which forms a first plane and a second plane, the first plane and the second plane intersecting at the inflection point.

Preferably, the angle between the first plane and the horizontal plane is Θ the angle between the second plane and the horizontal plane is θ ₂ , wherein 9 i < 45 ° and θ ₂ < 45 °.

Preferably, the measuring device further comprises an image capturing device, wherein the image capturing device is used to obtain A section of the object in the direction of the conveyor belt is obtained.

 Preferably, the assay device further includes a pressure sensor disposed below the conveyor belt at the inflection point.

 Through the above technical solution, the center of gravity can be determined by the intersection of the perpendicular lines of the center of gravity of the two passing objects by using a simple physical principle, and the non-contact measurement is realized by a simple measuring device and a simple measuring method, thereby improving work efficiency. And greatly improved the accuracy.

 Other features and advantages of the invention will be described in detail in the detailed description which follows. DRAWINGS

 The drawings are intended to provide a further understanding of the invention, and are in the In the drawing:

 1 is a schematic view of a prior art method for measuring a body weight height;

 Figure 2 is a plan view of the method for measuring the weight of the object according to Figure 1;

 Figure 3 is a schematic illustration of a first inversion moment of an object in accordance with a preferred embodiment of the present invention; Figure 4 is a schematic illustration of a second inversion moment of an object in accordance with a preferred embodiment of the present invention; Figure 5 is a preferred embodiment in accordance with the present invention Schematic diagram. Description of the reference numerals

 11 first plane 12 second plane

 2 pressure sensor li first vertical line

1 ₂ second perpendicular A inflection point

Oi first flip point 0 ₂ second flip point

Πι first straight line n ₂ second straight line

Θ 2 second plane and horizontal plane detailed description

 The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It is to be understood that the specific embodiments described herein are intended to be illustrative and not restrictive.

 In the drawings of the present invention, the direction indicated by the arrow is the direction of movement of the conveyor belt, that is, the direction of movement of the object.

 In the present invention, in order to describe in a language as concise as possible, while at the same time facilitating the understanding of those skilled in the art, some terms in the text need to be briefly explained, but the explanation and description here and the term itself are in the technical field. The usual meaning in the comparison does not create contradictions and ambiguities. The "inflection point" of the slope surface herein refers to the intersection of two planes formed by the conveyor belt. Since the technical solution of the present invention processes the image, the "inflection point" means that the image is taken from one side of the slope. In the image, the edge is simplified to a point; "flip" refers to the movement of the center of gravity of the object from one surface of the slope to the other, the process of contacting the bottom surface of the object from one surface to the other, that is, the center of gravity of the object Crossing the "inflection point", the "flip time" refers to the moment when the center of gravity of the object crosses the "inflection point".

Before the detailed description of the technical solution of the present invention, the physics principle on which the present invention is based will be first introduced. According to the principle of statics, the magnitude and direction of the action of the slope 2 on the object (including the support force perpendicular to the pressure of the slope 2 and the friction along the slope 2) when the object moves along the slope 2 Contrary to the gravity direction of the object, so that the object is balanced by force, that is, the force of the slope 2 should be on the vertical line of the support point of the over-slope 2 to the object. When the bottom surface of the object is in contact with a surface, The parts that are in contact support the object, so there is no single support point, but in any case, the direction of action of the force should pass the center of gravity of the object. When we know that an object is only subjected to gravity and force and is in equilibrium, if we know the position of the center of gravity, we can know the direction and magnitude of the force. The present invention is the principle of reverse application, when the object is only subjected to The action of gravity and force is in equilibrium, and the point of action and the direction of action are known. Then the center of gravity should be on the vertical line passing the support point. It is only necessary to find two vertical straight lines that meet the above conditions and the position of the center of gravity can be determined by their intersection.

 The invention provides a method for measuring the height of the center of gravity of an object, wherein the measuring method comprises the following steps:

 (a) forming a first plane 11 and a second plane 12 by a conveyor belt, the first plane 11 and the second plane 12 intersecting at the inflection point A;

(b) the bottom surface of the object is in contact with the conveyor belt and moves with the conveyor belt, the first turning moment of movement of the object from the first plane 11 to the second plane 12 past the inflection point A Determining a first perpendicular line passing through the inflection point A, and determining a second perpendicular line 1 passing through the inflection point A after the object moves from the second plane 12 toward the first plane 11 through a second inversion moment ₂ ;

(c) Obtaining an intersection point G between the first vertical line ^ and the second vertical line _{12 is} a center of gravity.

 According to FIG. 3 to FIG. 5, the above technical solution utilizes a conveyor belt to form the first plane 11 and the second plane 12, so that by the operation of the conveyor belt, the objects on the conveyor belt can be moved along the first plane 11 and the second plane 12, firstly Determine the perpendicular line of the overweight center when the object passes through the turning point of the inflection point A twice. The intersection point of the two perpendicular lines is the center of gravity of the object.

 The above measurement method is simple in operation, which not only reduces the complexity of the measurement method and the apparatus used, but also greatly improves the accuracy. Through the above technical solution, the center of gravity can be determined by the intersection of the perpendicular lines of the center of gravity of the two passing objects by using a simple physical principle, and the non-contact measurement is realized by a simple measuring device and a simple measuring method, thereby improving work efficiency. And greatly improved the accuracy.

Preferably, the angle between the first plane 11 and the horizontal plane is that the angle between the second plane 12 and the horizontal plane is Θ ₂ , where 9 i < 45° and θ ₂ < 45°.

The above gives a preferred range of the angle between the first plane 11 and the second plane 12 and the horizontal plane. Theoretically, the larger the angle between the first plane 11 and the second plane 12, the higher the measurement accuracy, but if the slope of the plane is too large, the friction of the object in the direction of the conveyor belt is reduced, and the object The gravity component along the direction of the conveyor belt increases, which makes it difficult for the object to move along the conveyor belt on the slope surface. Moreover, the angle between the two planes at the inflection point A is too large, causing the object to be violently flipped. It is likely that the flipping action is too severe. It affects the accuracy of the measurement results. It is therefore necessary to reasonably select the angle of inclination of the first plane 11 and/or the second plane 12 such that the angle between the two planes and the horizontal plane is preferably less than 45°, more preferably 9 i = as shown in Figures 3 to 5 15° , θ ₂ = 5°.

 Preferably, the first inversion moment and the second inversion moment are the starting moments of the object inversion process.

 When the object moves to the inflection point with the conveyor belt and starts to rotate around the inflection point A, it seems that only the inflection point A supports the object, but at this time the center of gravity is not on the vertical line passing through the inflection point A, which belongs to the research field of motion mechanics, and Does not meet the above physical principles, we will not discuss here. Moreover, before the object is turned over, although it is supported by the slope 2, the only support point cannot be found, and the center of gravity is not in the vertical line of the support point during the inversion of the object. When the object just starts to flip, only the inflection point A serves as the support point for the object on the slope surface 2, and the object has not started the rotation motion, and the center of gravity is still on the vertical line of the support point, which is consistent with the conditions of the above physical principle; At the moment when the object crosses the inflection point A so that the inversion ends, the portion of the bottom surface of the object crossing the inflection point A is all pressed against the other plane, so that the object is not supported by one supporting point at this time. Therefore, the turning moment referred to in the technical solution of the present invention includes the starting moment of the turning process.

Preferably, in step (b), the object is at a bottom edge of a vertical section along the direction of the conveyor belt, the bottom edge is located on the conveyor belt, and the length of the bottom edge is L; a first inversion point on the bottom edge of the first inversion moment and a second inversion point 0 ₂ on the bottom edge of the second inversion moment _; the first inversion point is made and vertical The angle between the straight directions is

Hey! a first straight line, and a second straight line n ₂ crossing the second inversion point 0 ₂ and having an angle θ ₂ from the vertical direction, the first straight line _ηι and the second straight line n ₂ respectively The first vertical line corresponds to the second vertical line 1 ₂ .

As shown in FIG. 5, in the above preferred embodiment of the present invention, in order to facilitate the object of the present invention, a vertical section of the crop body is first required, and the bottom edge of the vertical section is measured. The length, as described below, is based on the basis of the base. However, it should be noted that as long as the selection of the bottom side of the vertical section is arbitrary, it is only necessary to conform to the bottom edge of the vertical section on the conveyor belt, because the required first inversion point and second inversion point are required. 0 ₂ is the intersection of the object and the inflection point. Moreover, the shape or the like of the vertical cross section is not important, and the measurement method of the present invention requires only the length of the bottom side of the vertical section.

At the respective first inversion moment and second inversion moment, the center of gravity is located on the first vertical line ^ and the second perpendicular line 1 ₂ of the first inversion point (^ and the second inversion point 0 ₂ . Specifically, for example At the first inversion moment, the first perpendicular line should pass the first inversion point O and the angle between the bottom surface and the bottom surface of the object is related to the angle between the first plane 11 and the horizontal plane, and the second inversion moment is the same as the above situation and principle. , will not repeat them here.

Since the first and second vertical ^ ₁₂ perpendicular positional relationship with respect to the object through the first point and the second turning point of flipping _02, 11 and the first plane and the second plane 12 and the horizontal angle is determined. Therefore, in order to project the first vertical line ^ and the second vertical line 1 ₂ onto the same plane, the first perpendicular line and the second perpendicular line 1 are made with respect to the bottom side of the vertical section of the object to be made. _{2, the} corresponding first straight line and the second straight line n ₂ , the intersection point of the first straight line _ηι and the second straight line n ₂ intersecting is the center of gravity.

Preferably, the first inversion point and the second inversion point 0 ₂ are points respectively coincident with the inflection point A on the bottom edge of the object at the first inversion time and the second inversion time.

A further clear definition of the first rollover point and the second rollover point 0 ₂ is made. However, in the actual measurement, since the first plane 11 and the second plane 12 do not necessarily form protruding corners at the inflection point A, or due to measurement errors or the like, the first inversion point and the second inversion point 0 ₂ may not be A single point, but a point over a short segment of the line, but small errors do not have much effect on the final measurement.

 Preferably, at the first starting moment, the object is located at a first starting position, and at the second starting moment, the object is located at a second starting position;

Recording that the object moves from the first starting position to the inflection point A at a first speed _V1 and The first time when the inversion occurs and the second time t _{2 at} which the object moves from the second starting position to the inflection point A and the inversion occurs.

 Preferably, the object moves from the first plane 11 toward the second plane 12 with the conveyor belt,

 At the second starting moment, the object moves from the second plane 12 towards the first plane 11 with the conveyor belt.

 Preferably, in the first starting position, a distance between the first end point of the bottom edge away from the inflection point A and the inflection point A is

In the second starting position, the distance between the second end of the bottom edge away from the inflection point A and the inflection point A is L ₂ .

In the preferred embodiment, the first start time and the second start time are defined, respectively, the time at which the object moves from the first plane 11 and the second plane 12 toward the inflection point A, that is, the first time ^ and the first _two-time-12 start to the start time. Further defined are a first starting position and a second starting position, which are distances from the inflection point A of the first end point and the second end point of the object at the first starting time and the second starting time. That is to say, with a certain time as the timing start time, the time from the start of the movement of the object to the occurrence of the inversion, the moving speed of the object, and the distance from the end point of the inflection point A to the inflection point A are calculated.

 Preferably, a distance between the first end point of the bottom edge of the object and the first flip point DfL-Vi X t

Said bottom edge of said second end of the object and the second D flip distance between points _{0 2 2 = Lv 2 X t} T2?

In FIG. 5, taking the distance between the first endpoint and the first flip point as an example, the distance that the first endpoint moves within the first time ^ can be calculated by _V1 , and the termination time to the first time occurs. Flip, while the first end point is still on the first plane 11, so L- _Vl can find the distance between the first end point and the first flip point. The calculation of the distance D ₂ between the second end point and the second inversion point (0 ₂ ) is the same, and will not be described again. Preferably, the center of gravity height H = (LD! - D ₂ ) / (tan Θ _{1 + t} an θ ₂ ).

According to the geometric principle, according to the geometric principle, the first straight line! ^ The angle with the vertical direction is that the angle between the second straight line η ₂ and the vertical direction is θ ₂ , so the center of gravity height HX (tan e _1+tan θ ₂ ) can obtain the first straight line and the second straight line n ₂ The length of the line segment on the bottom edge of the object, that is, the distance L-Dd between the first inversion point and the second inversion point 0 ₂ can be obtained by the equation transformation.

Preferably, the first speed _V1 is equal to the second speed v ₂ .

The first speed and the second speed v ₂ can be set only by controlling the running speed of the conveyor belt, so that the measurement conditions of the first turning point of the object and the second turning point 0 ₂ can be made the same, thereby improving the accuracy of the measurement. And precision, and easy to calculate.

 Preferably, a pressure sensor 2 is disposed below the conveyor belt at the inflection point A, and the first inversion timing and the second inversion timing are determined based on a sudden change in the detected value of the pressure sensor 2.

 At the first inversion moment and the second inversion moment, the object is only subjected to the force of gravity and the inflection point A, so the force at the inflection point A is abruptly changed at this time. In order to better determine the turning moment, the present embodiment sets the pressure sensor 2 below the sensor 2 at the inflection point A, which is capable of detecting a sudden change in the pressure value when the object is turned over at the inflection point A.

Preferably, the pressure sensor 2 is connected to a timer to control the timer to record the first time ^ and the second time t ₂ . In the present embodiment, the purpose of the setting of the pressure sensor 2 is to better detect the turning moment. Therefore, the pressure sensor 2 can be connected to the timer to directly control the measurement of the time, or be connected to the controller, and then pass the controller and the timing. The connection time is measured.

Preferably, the vertical section of the object is obtained by an image capturing device, and the length of the bottom side of the vertical section is measured. For objects with regular or uniform cross-sectional shapes, such as rectangular bodies or cubes, the side shape is the cross-sectional shape, and for objects with irregular cross-sectional shapes, especially those with large volume and weight, it is often difficult to determine the shape of the cross-section. And size. In the present embodiment, the image capturing device is used to acquire the cross section, and the principle is the same as the projection, and the object to be measured is photographed from the side, so that the edge contour of the photographed object is the most With a large cross section, the length of the bottom edge of the section is measured on the image. It is also possible to directly perform the mapping process described above on the captured image to obtain the center of gravity, and finally determine the actual size by using the proportional relationship between the image size and the actual size. Using this method is not only simpler and easier to operate, but also more accurate.

 Preferably, the image capturing device comprises a camera and a camera. A preferred embodiment of the above image capturing apparatus.

 Further, each of the above preferred embodiments may be applied in any combination. For example, the pressure sensor 2 is used to control the opening of the image capturing device, so that the cross section and the turning point of the object can be directly captured at the turning moment, so that the distance of the turning point from the corresponding end point can be directly measured on the image without measuring the object. The time from the first/second starting position to the turning moment and the speed of the movement are then calculated.

 It is to be noted that, in the above method of the present invention, the key is to obtain the length of the bottom side of the vertical section, and the shape of the vertical section or the like is not important. For the object having an irregular vertical cross section, a vertical section can be obtained by the above preferred embodiment, and the length of the bottom side of the vertical section can be measured to utilize the measuring method of the present invention or directly on the image of the vertical section. The height of the center of gravity is obtained by the measuring method of the present invention.

 In addition, the present invention also provides an apparatus for measuring the height of the center of gravity of an object, wherein the measuring apparatus includes a conveyor belt that forms a first plane 11 and a second plane 12, the first plane 11 and the second plane 12 being The inflection point A intersects.

 As shown in Figures 3 to 5, the measuring device of the present invention can be used to carry out the measuring method of the present invention, which simply forms the first plane 11 and the second plane 12 by means of a conveyor belt, and places the object on the conveyor belt during the measurement, the object Having the bottom surface in contact with the conveyor belt and moving with the conveyor belt, using the physical principle (described in detail above, not repeated here) to measure the height of the center of gravity of the object of the flat bottom structure, through simple structure and operation Obtain high precision measurement results. Moreover, the measuring device performs the measurement by the above measuring method, and details are not described herein again.

Preferably, the angle between the first plane 11 and the horizontal plane is the second plane 12 and water The plane angle is θ ₂ , where 9 i < 45° and θ ₂ < 45°.

The above gives a preferred range of the angle between the first plane 11 and the second plane 12 and the horizontal plane. According to the principle of the measuring method applied by the measuring device of the present invention, theoretically, the larger the angle between the first plane 11 and the second plane 12, the higher the measurement accuracy, but if the slope of the plane is too large, The frictional force of the object in the direction of the conveyor belt is reduced, and the gravity component of the object along the conveyor belt is increased, thereby causing difficulty for the object to move along the conveyor belt on the slope surface, and the angle between the two planes at the inflection point is excessive. The sharp flipping action of the object is likely to affect the accuracy of the measurement result due to the excessively large flipping action. It is therefore necessary to reasonably select the angle of inclination of the first plane 11 and/or the second plane 12 such that the angle between the two planes and the horizontal plane is preferably less than 45°, more preferably 9 i = as shown in Figures 3 to 5 15° , θ ₂ = 5 °.

 Preferably, the measuring device further comprises an image capturing device for obtaining a vertical section of the object in the direction of the conveyor belt, and measuring the length of the bottom side of the vertical section.

 For objects with regular or uniform cross-sectional shapes, such as rectangular bodies or cubes, the side shape is the cross-sectional shape, and for objects with irregular cross-sectional shapes, especially those with large volume and weight, it is often difficult to determine the shape of the cross-section. And size. In the present embodiment, the image capturing device is used to acquire the cross section, and the principle is the same as the projection, and the object to be measured is photographed from the side, so that the edge contour of the photographed object is the largest cross section of the object, and the measurement is performed. The length of the base of the section is the desired length of the base. It is also possible to directly perform the mapping process described above on the captured image to obtain the center of gravity, and finally determine the actual size by using the ratio relationship between the image size and the actual size. Using this method is not only simpler and easier to operate, but also more accurate.

 Preferably, the assay device further comprises a pressure sensor 2 disposed below the conveyor belt at the inflection point.

According to the measuring principle applied by the measuring device of the present invention, at the first turning moment and the second turning moment, the object is only subjected to the force of gravity and the inflection point A, so the force at the inflection point A is emitted at this time. A mutation was born. In order to better determine the turning moment, the present embodiment provides a pressure sensor 2 below the sensor 2 at the inflection point A, which is capable of detecting a sudden change in the pressure value when the object is turned over at the inflection point A.

 According to the measuring method of the present invention, in the case where the shape of the vertical section of the object is irregular, resulting in difficulty in measuring the length of the base, it is usually necessary to first obtain the vertical section. The vertical cross section can be drawn on a medium such as paper or as a digital picture file, so that the preferred embodiment of the present invention is suitable for both manual processing and computer image processing. After obtaining the appropriate vertical cross section, mapping and calculation may be performed in accordance with a preferred embodiment of the present invention.

 The preferred embodiment of the present invention has been described by way of example only, and is not intended to limit the invention.

 By the above-described measuring device and measuring method, non-contact measurement of the height of the center of gravity of the object can be easily realized, the work efficiency is high, and the accuracy of the measurement result is high. Next, the error range of the measurement result is analyzed when the bottom side of the vertical section is acquired by the image capturing apparatus, and the following error analysis is merely illustrative.

The conveyor belt is operated at a certain speed V, the shooting time interval or frame interval of the image capturing apparatus 1 is At, the angle between the first vertical line and the second vertical line 1 ₂ is θ _{1 +} Θ ₂ , and the first vertical line Or the maximum offset of the second perpendicular 1 ₂ is v X At. According to the geometric relationship, the maximum offset of the height of the center of gravity on the first perpendicular is Ah^vX At/tg Θ = _v X At/tg ( θ _{1 +} θ ₂ ), the maximum offset of the height of the center of gravity at the second perpendicular 1 ₂ Ah ₂ = vX At / sin Θ = _V X At / sin ( θ _{1 +} θ ₂ ), therefore, the height of the center of gravity of the final measurement result The maximum offset Ah = Ah _{1 +} Ah ₂ = _V X AtX (l/tg ( θ _{1 +} θ ₂ ) + l / sin ( θ _{1 +} θ ₂ ) ).

When the object is tested with the conveyor belt at a speed of v=15 m/s at a first plane 11 at an angle of 9^15 ° from the horizontal plane and a second plane 12 at an angle of Θ ₂ = 5° to the horizontal plane, Using a 14.2 megapixel camera that shoots 15 photos per second (ie shutter speed l/15s), the maximum center of gravity height measurement is 6.076mm.

When the object follows the conveyor belt at a speed of v=15m/ _{s at} an angle of 9^15° to the horizontal plane When a plane 11 and a second plane 12 with an angle of θ ₂ = 5 ° are tested for motion, the camera is photographed using a resolution of 1920×1080, 20 frames per second, and the maximum deviation of the center of gravity is measured. 4.477mm.

When the object is tested with a conveyor belt moving at a speed of v=15 m/s at a first plane 11 at an angle of 9^15 ° from the horizontal plane and a second plane 12 at an angle θ ₂ = 5 ° to the horizontal plane, Using a resolution of 1624 X 1124, a camera shooting process of 30 frames per second, the maximum center-of-gravity offset was measured to be 2.933 mm.

 The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments, and various simple modifications of the technical solutions of the present invention may be made within the scope of the technical idea of the present invention. These simple variations are within the scope of the invention.

 It should be further noted that the specific technical features described in the above specific embodiments may be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention has various possibilities. The combination method will not be described separately.

 In addition, any combination of various embodiments of the invention may be made, as long as it does not deviate from the idea of the invention, and should also be regarded as the disclosure of the invention.

Claims

A method for measuring a height of a center of gravity of an object, wherein the measuring method comprises the following steps:  (a) forming a first plane (11) and a second plane (12) with a conveyor belt, the first plane (11) and the second plane (12) intersecting at the inflection point (A); (b) the bottom surface of the object is in contact with the conveyor belt and moves along the inflection point (A) from the first plane (11) to the second plane (12) as the conveyor belt moves (A) a first flipping moment determining a first vertical line passing through the inflection point (A) (1, and moving the object from the second plane (12) to the first plane (11) through a second flip Determining a second perpendicular (1 ₂ ) passing through the inflection point (A) _; (c) Obtaining the intersection (G) of the first perpendicular (1) and the second perpendicular (1 ₂ ) is the center of gravity. The measuring method according to claim 1, wherein the angle between the first plane (11) and the horizontal plane is the angle between the second plane (12) and the horizontal plane is θ ₂ , wherein 45° , θ ₂ < 45°. 3. The measuring method according to claim 1, wherein the first inversion time and the second inversion time are start times of the object inversion process. 4. The measuring method according to claim 1, wherein in the step (b), the object is at a bottom edge of a vertical section in the direction of the conveyor belt, the bottom edge is located on the conveyor belt, and The length of the bottom edge is L, Determining a first inversion point (0 of the object on the bottom edge of the first inversion moment and a second inflection point (0 ₂ ) on the bottom edge of the second inversion moment, a first straight line ( _ηι ) having the first inversion point (0 and an angle of 9 i with the vertical direction, and the second inversion point (0 ₂ ) and an angle θ with the vertical direction ₂ is a second straight line (η _2), the first and second straight lines ([eta] ₂₎ with said first perpendicular (1 and a second vertical line _(12), respectively. The measuring method according to claim 4, wherein the first inversion point (0 and the second inversion point (0 ₂ ) are respectively at the first inversion time and the second inversion A point on the bottom edge of the object that coincides with the inflection point (Α). 6. The method according to claim 4, wherein  The first starting moment, the object is located at a first starting position, and at the second starting moment, the object is located at a second starting position; Recording a first time when the object moves from the first starting position to the inflection point (Α) at a first speed and flipping, and the object is from the second starting position at a second speed v ₂ The second time t _{2 is} moved to the inflection point (A) and flipped. 7. The method according to claim 6, wherein  At the first starting moment, the object moves from the first plane (11) toward the second plane (12) with the conveyor belt,  At the second starting moment, the object moves from the second plane (12) toward the first plane (11) with the conveyor belt. 8. The method according to claim 6, wherein  In the first starting position, the distance between the first end of the bottom edge away from the inflection point (A) and the inflection point (A) is In the second starting position, the second end of the bottom edge away from the inflection point (A) The distance of the inflection point (A) is L _: 9. The method according to claim 8, wherein a distance between the first end point of the bottom edge of the object and the first flip point (0)

A distance D ₂ between the second end point of the bottom edge of the object and the second inversion point (0 ₂ ) is Lv ₂ X t ₃ . 10. The method according to claim 9, wherein The height of the center of gravity H = (L - Df D ₂ ) / (tan e _{1 +} tan e ₂ ) ₀ The measuring method according to claim 6, wherein the first speed _V1 is equal to the second speed v ₂ . The measuring method according to claim 6, wherein a pressure sensor (2) is disposed under the conveyor belt at the inflection point (A), and the detected value of the pressure sensor (2) is abruptly changed to determine the The first inversion moment and the second inversion moment. 13. The measuring method as claimed in claim 12, wherein the pressure sensor (2) is connected with a timer to control the timer recording of the ^ first time and the second time t _2. The measuring method according to claim 4, wherein a vertical section of the object is obtained by an image capturing device, and a length of a bottom side of the vertical section is measured. The measuring method according to claim 14, wherein the image capturing device comprises a camera and a camera. 16. Apparatus for determining the height of the center of gravity of an object, characterized in that said measuring means comprises a conveyor belt forming a first plane (11) and a second plane (12), said first plane (11) intersects the second plane (12) at the inflection point (A). The measuring device according to claim 16, wherein the angle between the first plane (11) and the horizontal plane is the angle between the second plane (12) and the horizontal plane is θ ₂ , wherein 45°, θ ₂ <45°. 18. The assay device according to claim 16, wherein the assay device further comprises an image capture device for obtaining a vertical cross section of the object in the direction of the conveyor belt. The measuring device according to claim 16, characterized in that the measuring device further comprises a pressure sensor (2) which is disposed below the conveyor belt at the inflection point (Α).