WO2016043227A1

WO2016043227A1 - Mass measurement device

Info

Publication number: WO2016043227A1
Application number: PCT/JP2015/076327
Authority: WO
Inventors: 亮民鈴木; 誠中谷; 白石　元彦; 泰彦金井; 友厚谷口
Original assignee: 株式会社イシダ
Priority date: 2014-09-20
Filing date: 2015-09-16
Publication date: 2016-03-24
Also published as: JP6513357B2; JP2016061748A

Abstract

Provided is a mass measurement device that is for addressing a problem unique to mass measurement devices incorporated into robot hands and is capable of minimizing measurement error even if there are differences in robot hand gripping mechanisms, robot hand operation modes, or article types. The device stores, in association with the type of a second article of a known mass (m2) and of a different type than a first article of a mass (m1), first outputs (Fmz, Faz) of each sensor when a gripping mechanism for gripping an article holds and moves the first article, the mass (m1), second outputs (Fms, Fas) of each sensor when the gripping mechanism holds and moves the second article, and the known mass (m2). When the type of the second article is specified, the known mass (m2) and the second outputs (Fms, Fas) for the second article of the specified type and the mass (m1) and first outputs (Fmz, Faz) for the first article are read out, and the mass of an article of an unknown mass is calculated.

Description

Mass measuring device

The present invention relates to a mass measuring device that detects the mass of an article while the speed of the article is changing.

In spring balances and electronic balances, in order to eliminate the influence of acceleration other than gravitational acceleration, it is assumed that the mass is measured while the article is stationary. However, recently, the opportunity to lift and move an article with a robot hand increases, and accordingly, there is a demand for detecting the mass of the article when it is lifted and using it for post-processing.

In order to meet this requirement, the applicant has developed a series of mass measuring devices as disclosed in the following patent documents. This mass measuring device is intended to measure the mass of an article from the force and acceleration acting on the article while the speed of the article changes.

As shown in FIG. 1, the basic configuration of the mass measuring apparatus 10 includes a force sensor 1 that detects a force acting on the article Q, a robot hand 2 that holds the article Q, and a robot that moves the article Q while accelerating it. An arm 3 and an acceleration sensor 4 that detects acceleration acting on the article Q are provided.

The force sensor 1 is provided between the robot hand 2 and the robot arm 3, and the acceleration sensor 4 is provided adjacent to the robot hand 2. When the mass measuring device 10 having such a configuration is represented by a spring-mass system, it can be represented by a two-degree-of-freedom model as shown in FIG.

Based on this model, the principle of measuring the mass of an article during acceleration will be described below.
In FIG. 2, m is the mass of the article Q, M ₁ is the mass of the force sensor 1, and M ₂ is the mass of the acceleration sensor 4. K ₁ is the spring constant of the force sensor 1, and k ₂ is the spring constant of the acceleration sensor 4. x ₁ is the displacement amount of the force sensor 1, and x ₂ is the displacement amount of the acceleration sensor 4. These displacement amounts should be calculated by decomposing into three axes of X, Y and Z, but the result will be the same regardless of which axis is calculated. ing.

In this model, the equation of motion when acceleration acts on the article Q is
(M + M ₁ ) d ² x ₁ / dt ² = −k ₁ (x ₁ −y) + k ₂ (x ₁ −x ₂ ) (1)
M ₂ d ² x ₂ / dt ² = −k ₂ (x ₂ −x ₁ ) (2)
Represented as: Moreover, when the equation (1) is transformed,
m = [− k ₁ (x ₁ −y) + k ₂ (x ₁ −x ₂ )] / (d ² x ₁ / dt ² ) −M ₁ (3)
It becomes. Furthermore, considering that the rigidity of the acceleration sensor 4 is large,
d ² x ₁ / dt ² ≈d ² x ₂ / dt ² (4)
Can be approximated as Therefore, from equations (3) and (4)
m = [− k ₁ (x ₁ −y) + k ₂ (x ₁ −x ₂ )] / (d ² x ₂ / dt ² ) −M ₁ (5)
Is derived. Moreover, when the equation (2) is transformed,
d ² x ₂ / dt ² = −k ₂ (x ₂ −x ₁ ) / M ₂ (6)
Therefore, from equations (5) and (6),
m = [− k ₁ (x ₁ −y) / − k ₂ (x ₂ −x ₁ )] M ₂ + M ₂ −M ₁ (7)
Is derived.

Here, −k ₁ (x ₁ −y) is the output of the force sensor 1, and −k ₂ (x ₂ −x ₁ ) is the output of the acceleration sensor 4. These outputs are related to the mass. Therefore, the output of each sensor when the robot hand 2 accelerates without anything is obtained as a zero point, and then the output when the robot hand 2 accelerates with a weight having a known mass is obtained. It is necessary to obtain the span coefficient.

FIG. 3 is a graph showing changes in output data of the force sensor 1 and the acceleration sensor 4 when the robot hand 2 is accelerated up and down in a no-load state in order to obtain a zero point. In this figure, when the peak value of the output data of the force sensor 1 is Fmz and the peak value of the output data of the acceleration sensor 4 is Faz,
0 = M ₂ · C · (Fmz / Faz) + M ₂ −M ₁ (8)
It becomes. However, assuming that Faz is not 0, C is a conversion factor.

FIG. 4 is a graph showing changes in output data of the force sensor 1 and the acceleration sensor 4 when a mass ms of mass is held in the robot hand 2 and accelerated up and down. In this figure, when the peak value of the output data of the force sensor 1 is Fms and the peak value of the output data of the acceleration sensor 4 is Fas,
ms = M ₂ · C · (Fms / Fas) + M ₂ −M ₁ (9)
It becomes. From the equations (8) and (9),
C = ms / M ₂ {(Fms / Fas) − (Fmz / Faz)} (10)
Is derived. Also, from equation (10), since M ₂ is a constant, if the span coefficient is set to S,
S = C · M ₂ = ms / {(Fms / Fas) − (Fmz / Faz)} (11)
It becomes.

FIG. 5 is a graph showing changes in output data of the force sensor 1 and the acceleration sensor 4 when the article Q having the mass m is held in the robot hand 2 and accelerated up and down. In this figure, when the peak value of the output data of the force sensor 1 is Fm and the peak value of the output data of the acceleration sensor 4 is Fa,
m = S {(Fm / Fa)-(Fmz / Faz)} (12)
It becomes. Accordingly, the output of the force sensor 1 when the robot hand 2 is accelerating the article Q by obtaining the span coefficient S, the output (Fmz) of the force sensor 1 at no load, and the output (Faz) of the acceleration sensor 4. If (Fm) and the output (Fa) of the acceleration sensor 4 are detected, the mass m of the article Q can be measured.

Here, the peak value of the output data of each sensor is adopted because there is a difference in the frequency characteristics of the force sensor and the acceleration sensor, resulting in a phase shift in each output data. This is a measure to minimize it.

JP 2013-079931 A JP 2013-174503 A JP 2013-174570 A JP 2013-185846 A JP 2013-185847 A JP 2013-185848 A JP 2013-195200 A

As described above, if the equation (12) is used, the mass of the article can be obtained even during acceleration. However, since the equation (12) is derived based on the two-degree-of-freedom model, when vibration is applied to the robot hand, for example, when carrying a bag-packed product or a bottled product with the robot hand, the contents are In order to move, a new vibration is added, which causes an error in the measured value. Also, an error occurs in the measured value depending on the type of the gripping mechanism of the robot hand. For example, when an article is gripped by a bellows-like suction pad to which negative pressure is applied, the suction pad expands and contracts during acceleration, and an error occurs in the measurement value due to the influence.

In addition, errors in the measured values may occur depending on the operation mode of the robot hand. For example, an error occurs in the measured value even when moving linearly between two points and when moving in a circular arc shape (using a centrifugal force).

The present invention is intended to solve the problems peculiar to the mass measuring device incorporated in such a robot arm, and even if there is a difference in the article gripping mechanism and operation mode of the robot arm, or there is a difference in the kind of article. Even if it exists, it aims at providing the new mass measuring device which can suppress a measurement error to the minimum.

The mass measuring device according to the present invention is a mass measuring device for measuring the mass of the article from the force and acceleration acting on the article while the speed of the article is changing,
A gripping mechanism for gripping the article;
A moving mechanism for moving the gripping mechanism;
A force sensor provided between the gripping mechanism and the moving mechanism for detecting a force acting on the article while the speed is changing;
An acceleration sensor that detects acceleration acting on the article while the speed is also changing;
The first output (Fmz, Faz) of each sensor and the reference mass when the first article having the reference mass including zero mass is moved while changing the speed, and the type of the gripping mechanism The second output (Fms, Fas) of each sensor and the known mass when the second article having a different known mass is moved while changing its speed are stored in correspondence with the type of the second article. The first table;
Article designating means for designating the type of the second article;
The known mass corresponding to the second article of the specified type and its second output (Fms, Fas), and the reference mass of the first article and its first output (Fmz, Faz) from the first table. First reading means for reading;
A span coefficient calculating means for calculating a span coefficient based on each read output (Fmz, Faz, Fms, Fas) and the known mass and the reference mass;
The article of unknown mass based on the calculated span coefficient, the read first output (Fmz, Faz), and the output of each sensor when the specified kind of article is gripped and moved Computing means for calculating the mass of
It is provided with.

When lifting an article with a robot hand, if the article is a bag-packed product or a bottled product, the contents move and vibration is applied to the robot hand, thereby causing an error in the output of each sensor. In order to suppress such errors, here, articles that cause an error in the output of each sensor are positioned as "different types" articles, and basic data (Fmz, Faz, Fms, Fas, known mass, reference mass). Then, when the type of article is specified, basic data corresponding to the specified type of article is read out and a span coefficient is calculated. Based on the span coefficient, an article of unknown mass of the specified type is Find the mass.

In this case, the article that is gripped by the gripping mechanism vibrates during movement and causes an error in the output of each sensor, such as a bag-packed product or a bottled product. Although it is preferable to use an article of the same type, it is not necessary to use the same kind of article. Moreover, an article with zero mass may be used. An article with zero mass corresponds to a case where the article is not gripped, and “when the first article with zero mass is gripped” means that the gripping mechanism does not grip the article and holds the gripping mechanism in an unloaded state. Is moved to output a first output from each sensor.

In addition, when using a first article having a mass, the first output (Fmz, Faz) of each sensor when the grasping mechanism grips the first article having the reference mass m1 and accelerates it is stored. The second output (Fms, Fas) of each sensor when the second article of known mass m2 is gripped and accelerated is stored, and the difference between the output and each mass (m2−m1) = ms The span coefficient S is obtained from the equation (11).

Specifically, for example, two articles of the same type to be measured are prepared, and their masses are measured in advance with a precision balance. Next, one article whose mass is known is a first article, and a combination of both articles is a second article. First, the first article is gripped by the gripping mechanism to determine the first output, and then both the articles are gripped by the gripping mechanism to determine the second output. Since the difference ms between the first load mass and the second load mass obtained is the mass of the other article, the span coefficient S is obtained from the above equation (11) with the mass of the other article.

In the first invention, each time a type of an article is specified, basic data (Fmz, Faz, Fms, Fas, known mass, reference mass) of the article corresponding to the type is read from each storage means, and a span coefficient is obtained. Instead of this, instead of this, the span coefficient corresponding to the type of article is stored in advance, and when the type of article is specified, the span coefficient corresponding to that type is read out. Also good. At this time, when obtaining the mass of the article of unknown mass, the ratio (Fmz / Faz) of the first output when the first article is measured from the equation (12) is required. It may be stored together with the coefficient and read out together with the span coefficient.

The second invention stores the span coefficient and the ratio of the first output in advance. The gripping mechanism for gripping an article, the moving mechanism for moving the gripping mechanism, the gripping mechanism, and the movement according to the first invention. And a force sensor that detects a force acting on the article while the speed is changing, and an acceleration sensor that detects an acceleration acting on the article while the speed is changing. In addition to
The first output (Fmz, Faz) of each sensor and the reference mass when the first article having the reference mass including zero mass is moved while changing the speed, and the type of the gripping mechanism Span coefficients calculated based on the second outputs (Fms, Fas) of the sensors and the known masses when the second articles having different known masses are moved while changing their speeds, the first output (Fmz, Faz) or its output ratio (Fmz / Faz) together with the first span coefficient table stored corresponding to the type of the second article,
Article designating means for designating the type of the second article;
A second reading means for reading out a span coefficient corresponding to the second article of the specified type and the first output (Fmz, Faz) or its output ratio (Fmz / Faz) from the first span coefficient table;
Based on the read span coefficient, the first output (Fmz, Faz) or its output ratio (Fmz / Faz), and the output of each sensor when a specified type of article is held and moved Calculating means for calculating the mass of the article of unknown mass;
It is provided with.

Also in this case, when an error occurs in the output depending on the article, the span coefficient is obtained by using the same kind of article as the first article and the second article. Otherwise, the span coefficient may be obtained using a reference weight. In addition, an article having a mass of zero means that the gripping mechanism is moved in an unloaded state without causing the gripping mechanism to grip any article as described above, and the first output is output from each sensor.

In the second invention, the span coefficient and the first output ratio (Fmz / Faz) for each type are obtained from the basic data (Fmz, Faz, Fms, Fas, known mass, reference mass) corresponding to the type of article. The span coefficient and the first output ratio (Fmz / Faz) are stored in the span coefficient table in association with the type of article. If the article is designated, the span coefficient corresponding to the designated article and the first output (Fmz, Faz) or its output ratio (Fmz / Faz) are read from the span coefficient table to calculate the mass of the article. Use it. Thereby, the mass of the article can be calculated in a short time.

The first and second inventions described above handle a plurality of types of articles with a single type of gripping mechanism. However, when the type of the gripping mechanism changes, the vibration characteristics received by each sensor may change. For example, the gripping mechanism includes a type that grips an article with a plurality of fingers, and a type that grips an article with an accordion-shaped suction pad on which negative pressure is applied. When gripping an article with the former finger type, the vibration of the gripping mechanism itself is not considered, but when gripping an article with the latter suction pad, the suction pad expands and contracts during acceleration. May cause an error in the output of each sensor. The vibration also changes depending on the suction force and suction position of the suction pad, the mass of the article to be sucked, and the like.

Therefore, in the third invention, there is provided a mass measuring apparatus that handles a single type of article with a plurality of types of gripping mechanisms, the gripping mechanism for gripping an article of the first invention, and a movement for moving the gripping mechanism. A mechanism, a force sensor provided between the gripping mechanism and the moving mechanism for detecting a force acting on the article while the speed is changing, and the article while the speed is changing In addition to an acceleration sensor that detects acceleration acting on
The first output (Fmz, Faz) of each sensor and its reference mass when the first article having a reference mass including zero mass is moved while changing the speed thereof, and the gripping mechanism are known. A second table in which the second output (Fms, Fas) of each sensor when the second article of mass is moved while changing its speed and the known mass are stored corresponding to different types of gripping mechanisms; ,
Gripping mechanism designating means for designating the type of gripping mechanism to be used;
Each output (Fmz, Faz, Fms, Fas) corresponding to the designated type of gripping mechanism, and a third reading means for reading the reference mass and the known mass from the second table;
A span coefficient calculating means for calculating a span coefficient based on each read output (Fmz, Faz, Fms, Fas) and the known mass and the reference mass;
Based on the calculated span coefficient, the read first output (Fmz, Faz), and the output of each sensor when the article is gripped and moved, the mass of the article having an unknown mass is calculated. Computing means;
It is provided with.

Since the third invention selects one gripping mechanism from a plurality of gripping mechanisms of different types and grips one type of article, in the case of a bag-packed product whose contents move, the same as described above. , Prepare two articles of known mass of the same type, one as the first article and the combination of both as the second article, and the first output (Fmz, Faz) and the second output ( Fms, Fas) are obtained and stored. Then, when the gripping mechanism is replaced with a different type, the basic data (Fmz, Faz, Fms, Fas, known mass, reference mass) corresponding to the newly mounted gripping mechanism is read and the span coefficient is calculated. The mass of the article of unknown mass is calculated using the coefficient.

The types of gripping mechanisms include, for example, a finger type and an air adsorption type, and the “grip mechanisms of different types” here mean gripping mechanisms in which the output of each sensor changes. Therefore, for example, a mechanism in which the output of each sensor changes depending on the number of suction pads or the suction force is included in the “different types of gripping mechanisms” herein.

In the third invention described above, when the gripping mechanism is replaced with a different type, the basic data (Fmz, Faz, Fms, Fas, known mass, reference mass) corresponding to the newly mounted gripping mechanism is read and the span coefficient is read. However, instead of this, the span coefficient corresponding to the type of the gripping mechanism and the first output (Fmz, Faz) or its output ratio (Fmz / Faz) are stored in advance, and the gripping mechanism When the type of the specified value is designated, the span coefficient corresponding to the type and the first output (Fmz, Faz) or the output ratio (Fmz / Faz) may be read out.

The next fourth invention stores such a span coefficient in advance, and includes a gripping mechanism for gripping an article, a moving mechanism for moving the gripping mechanism, and a gripping mechanism and the moving mechanism according to the first invention. In addition to a force sensor for detecting a force acting on the article while the speed is changing, and an acceleration sensor for detecting an acceleration acting on the article while the speed is changing And
The first output (Fmz, Faz) of each sensor and its reference mass when the first article having a reference mass including zero mass is moved while changing the speed thereof, and the gripping mechanism are known. The span coefficient calculated based on the second output (Fms, Fas) of each sensor when the second article of mass is moved while changing its speed and the known mass is used as the first output (Fmz, Faz) or its output ratio (Fmz / Faz), and a second span coefficient table stored corresponding to different types of gripping mechanisms;
Gripping mechanism designating means for designating the type of gripping mechanism to be used;
A fourth reading means for reading out a span coefficient corresponding to a specified type of gripping mechanism and the first output or its output ratio from the second span coefficient table;
An arithmetic means for calculating the mass of the article of unknown mass based on the read span coefficient, the first output or its output ratio, and the output of each sensor when the article is gripped and moved, It is provided with.

A fifth invention is a mass measuring apparatus in which a plurality of different types of gripping mechanisms are handled, and a plurality of different types of articles are handled by one of the gripping mechanisms, and the gripping mechanism for gripping an article according to the first invention is provided. A mechanism, a moving mechanism that moves the gripping mechanism, a force sensor that is provided between the gripping mechanism and the moving mechanism, and detects a force acting on the article while the speed is changing, An acceleration sensor that detects acceleration acting on the article while the speed is changing;
The first output (Fmz, Faz) of each sensor and the reference mass when the first article having the reference mass including zero mass is moved while changing the speed, and the type of the gripping mechanism The second output (Fms, Fas) of each sensor and the known mass when the second article having a different known mass is moved while changing the speed thereof correspond to the type of the second article. A third table stored corresponding to different gripping mechanisms;
Gripping mechanism designating means for designating the type of gripping mechanism to be used;
Article designating means for designating the type of the second article to be gripped by the designated type of gripping mechanism;
A fifth reading means for reading each output (Fmz, Faz, Fms, Fas) corresponding to the gripping mechanism designated by each designation means and the second article, and a reference mass and a known mass from the third table;
A span coefficient calculation means for calculating a span coefficient based on each read output (Fmz, Faz, Fms, Fas) and the known mass and the reference mass;
Based on the calculated span coefficient, the read first output (Fmz, Faz) or its output ratio (Fmz / Faz), and the output of each sensor when the article is held and moved, it is unknown Computing means for calculating the mass of the article of mass;
It is provided with.

The fifth aspect of the present invention provides basic data (Fmz, Faz, Fms, Fas, known mass, reference mass) corresponding to the newly installed gripping mechanism and the type of the article each time the mounted gripping mechanism and the type of the article are changed. ) To calculate the span coefficient, but instead, the span coefficient corresponding to the type of the gripping mechanism and the type of article and the first output (Fmz, Faz) or its output ratio (Fmz / Faz) ) In advance, and when the gripping mechanism and the type of article are specified, the span coefficient and the first output (Fmz, Faz) or the output ratio (Fmz / Faz) corresponding to the type are read out. May be.

The next sixth invention stores such a span coefficient in advance, and includes a gripping mechanism for gripping an article, a moving mechanism for moving the gripping mechanism, a gripping mechanism, and the moving mechanism of the first invention. In addition to a force sensor for detecting a force acting on the article while the speed is changing, and an acceleration sensor for detecting an acceleration acting on the article while the speed is changing And
The first output (Fmz, Faz) of each sensor and the reference mass when the first article having the reference mass including zero mass is moved while changing the speed, and the type of the gripping mechanism The second article having a different known mass is calculated based on the second output (Fms, Fas) of each sensor when the second article is moved while changing its speed and the known mass, and classified by type of the second article. And a first span (Fmz, Faz) or its output ratio (Fmz / Faz) together with a third span coefficient table stored corresponding to different types of gripping mechanisms,
Gripping mechanism designating means for designating the type of gripping mechanism to be used;
Article designating means for designating the type of the second article to be gripped by the designated type of gripping mechanism;
A sixth reading means for reading out the span coefficient corresponding to the gripping mechanism and the second article designated by each designation means and the first output or its output ratio from the third span coefficient table;
Based on the read span coefficient, the first output (Fmz, Faz) or its output ratio (Fmz / Faz), and the output of each sensor when a specified type of article is held and accelerated. Calculating means for calculating the mass of the article of unknown mass;
It is provided with.

In the fifth and sixth inventions described above, different types of articles are gripped by different types of gripping mechanisms. Even when the same article is gripped by the same gripping mechanism, each sensor is different if the operation mode of the gripping mechanism is different. An error may occur in the output of. For example, when the operation for obtaining the basic data (Fmz, Faz, Fms, Fas) for obtaining the span coefficient is different from the operation for measuring the mass of the article while actually moving the gripping mechanism, for example, the article When a new acceleration or centrifugal force is applied by a different operation when gripping and moving the sensor, the output of each sensor changes, and sometimes an error occurs in each output. Therefore, it is necessary to acquire basic data (Fmz, Faz, Fms, Fas) in the same operation mode as the operation mode for gripping an article.

The seventh invention is a mass measuring apparatus capable of meeting such a demand, and in addition to the configurations of the first to sixth inventions, the first output (Fmz, Faz) and the second from each of the sensors. When the operation mode of the moving mechanism when the output (Fms, Fas) is acquired and the operation mode when measuring the mass of the unknown mass while changing the speed are different, the basic data (Fmz, Faz, Fms) , Fas, reference mass, known mass) is provided with a warning means for warning that it will be retaken under the latter operation mode.

At the time of operation, first, basic data (Fmz, Faz, Fms, Fas, reference mass, known mass) is acquired and then the normal operation is started. At that time, when the operation mode when the basic data is acquired is switched. The warning means displays a warning message that prompts the user to retake basic data. When basic data is acquired under a new operation mode, if the basic data and the new operation mode are stored in association with each other, the basic data is stored even if the operation mode is switched to the new operation mode. There is no need to retake.

The eighth invention is a mass measuring apparatus capable of such correspondence, and in addition to the configuration of the seventh invention, the operation mode set in the moving mechanism is associated with each table created under the operation mode. And a fourth table stored therein.

Thereby, even if the operation mode of the moving mechanism is changed, the basic data corresponding to the operation mode is read and set from the fourth table, so that the measurement error can be further reduced.

According to the present invention, even when various types of different articles are gripped by different types of gripping mechanisms, and even when there is a difference in operation mode when moving the articles, measurement errors caused by the sensors are different. Can be minimized.

The schematic block diagram for demonstrating the measurement principle of the mass measuring device which concerns on this invention. FIG. 2 is a diagram illustrating a two-degree-of-freedom model in which the mass measuring device of FIG. 1 is represented by a spring-mass system. The graph which shows the output of each sensor when not making a gripping mechanism hold | grip. The graph which shows the output of each sensor when a grasping mechanism is made to grasp a known weight. The graph which shows the output of each sensor when an article of mass m is made to grasp by a grasping mechanism. 1 is a schematic configuration diagram of a mass measuring device according to an embodiment of the present invention. The schematic block diagram which shows another example of the holding | grip mechanism used in the said embodiment. The configuration block diagram of the embodiment. The schematic block diagram of the signal processing circuit which processes the output signal of each sensor. 1 is a configuration block diagram of a first embodiment. The table | surface which shows an example of a 1st table. The configuration block diagram of a 2nd embodiment. The table | surface which shows an example of a 1st span coefficient table. The configuration block diagram of a 3rd embodiment. The table | surface which shows an example of a 2nd table. The configuration block diagram of a 4th embodiment. The table | surface which shows an example of a 2nd span coefficient table. The configuration block diagram of a 5th embodiment. The table | surface which shows an example of a 3rd table. The configuration block diagram of a 6th embodiment. The table | surface which shows an example of a 3rd span coefficient table. The configuration block diagram of a 7th embodiment. The configuration block diagram of an 8th embodiment. The figure which shows an example of the 4th table which memorize | stored the content of each table according to operation mode.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments do not limit the technical scope of the present invention.

(1) Basic Configuration of Mass Measuring Device FIG. 6 is a schematic configuration diagram of a mass measuring device 100 according to an embodiment of the present invention. In this figure, a mass measuring apparatus 100 includes a moving mechanism 11 as a robot arm, a force sensor 21 for detecting a force acting on a moving article Q, an acceleration sensor 22 for detecting an acceleration acting on the article Q, And a gripping mechanism 23 for gripping the article Q.

The moving mechanism 11 is a robot arm that three-dimensionally moves the gripping mechanism 23, and one end of the force sensor 21 is fixed to the tip base portion 12. As the moving mechanism 11, for example, a horizontal articulated robot, a vertical articulated robot, a parallel link robot, or the like is appropriate.

For the force sensor 21, for example, a strain gauge type load cell is employed. The strain gauge type load cell detects a force applied to the free end side by the displacement of the free end side relative to the fixed end side due to the load of the article Q. An acceleration sensor 22 and a gripping mechanism 23 are provided on the free end side of the force sensor 21.

As the acceleration sensor 22, for example, any of a strain gauge type load cell, a MEMS type small acceleration sensor, and a general commercially available acceleration sensor is appropriately employed.

The gripping mechanism 23 is a robot hand that grips the article Q. The gripping mechanism 23 of FIG. 6 shows an example of a finger type, but instead of this, an air adsorption type that adsorbs and holds the article Q with a negative pressure as shown in FIG. 7 can be used. The finger type of FIG. 6 is suitable when the article Q is a solid material, and the air adsorption type of FIG. 7 is suitable when the shape is not constant, such as a bag-packed product.

FIG. 7 shows a schematic configuration diagram of an air adsorption type. In this type, a bellows-like suction pad P made of silicon rubber is attached to an aluminum box B so that the suction pad P communicates with the inside of the box B. By holding the inside of the aluminum box B at a negative pressure, the articles Q are sucked and held by the suction pads P. In addition, since a plurality of articles Q may be simultaneously held by a large number of suction pads P, the number, shape, arrangement, etc. of the suction pads are appropriately changed according to the type of the articles Q. Accordingly, a plurality of types of gripping mechanisms 23 are prepared according to the type of the article Q, and these are used properly according to the type of the article Q.

(2) Basic Configuration of Control System FIG. 8 is a block diagram of the control system of the mass measuring apparatus 100. In FIG. 8, a moving mechanism 11, a gripping mechanism 23, a force sensor 21, an acceleration sensor 22, an input unit 24, and a display unit 25 are electrically connected to a control board 50 having a control unit 40 and a storage unit 30. .

The input unit 24 is a device for the operator to set the basic data (Fmz, Faz, Fms, Fas, reference mass, known mass) in the operation mode of the moving mechanism 11 and the mass measuring device 100 before starting operation. is there. Furthermore, it becomes an apparatus which designates the type of the article Q to be measured and the type of the gripping mechanism 23 that grips it. Specifically, it is composed of a keyboard and a touch panel.

The display unit 25 is a device that displays the operation status of the mass measuring apparatus 100 and an operation guide for setting the basic data. In addition, when the operation mode during operation is different from the operation mode for obtaining the span coefficient, an error display may be performed in order to eliminate the measurement error.

The storage unit 30 stores the above-described basic data and span coefficient as the mass measuring device 100 according to the type of the article Q and the gripping mechanism 23, and stores various tables described below.

The storage unit 30 also stores an operation mode of the moving mechanism 11 for how to move the gripping mechanism 23. For example, a series of “the article Q is sucked and held by the gripping mechanism 23, the article Q is moved from the suction position to the packing position by the moving mechanism 11, the mass is measured during that time, and then the article Q is placed in the packing container”. When performing the operation, an operation mode peculiar to the robot, such as operation from the suction position to the packing position with 80% capacity of the specified value, and operation with 50% capacity in the process of storing in the packing container is stored. ing.

The control unit 40 moves the gripping mechanism 23 based on the stored operation mode. In synchronization with the movement, the controller 40 sequentially reads the outputs of the force sensor 21 and the acceleration sensor 22 and determines the maximum value of the outputs of the

sensors

21 and 22. I will do it. The control unit 40 is constituted by a DSP (digital signal processor), a microcomputer, and the like, and executes various programs stored in the storage unit 30 to thereby read out means, span coefficient calculation means, calculation means, etc., which will be described later. Perform the function.

FIG. 9 shows an example of a signal processing circuit diagram for processing the detection signals of the force sensor 21 and the acceleration sensor 22. In FIG. 9, A /

D converters

27a and 27b are connected to the force sensor 21 and the acceleration sensor 22 via

amplifiers

26a and 26b, respectively. The A /

D converters

27 a and 27 b convert the input analog signal into a digital signal and input it to the control unit 40.

The control unit 40 performs a filtering process based on the input detection signal in a DSP (digital signal processor). For example, noise frequency components included in detection signals of the force sensor 21 and the acceleration sensor 22 are removed by a low-pass filter. Subsequently, the detection signal of the force sensor 21 from which the noise frequency component has been removed is divided by the detection signal of the acceleration sensor 4, and the tare mass is subtracted from the division result to calculate the mass m.
The tare mass is the sum of the tare mass loaded on the force sensor 21, the mass of the gripping mechanism 23, and the mass of the acceleration sensor 22.

<First Embodiment>
FIG. 10 shows a configuration block diagram of the first embodiment. In the storage unit 30 in this figure, a first table 31 as shown in FIG. 11 is stored. The first table 31 includes a first output (Fmz, Faz) of each

sensor

21 and 22 and its reference mass (when the gripping mechanism 23 grips and moves the first article of the reference mass m1 including zero mass). Zero or m1), and the second output (Fms, Fas) of each

sensor

21 and 22 and its known mass (m2) when the gripping mechanism 23 grips and moves the second article of known mass (m2). Is stored in correspondence with the type of the second article.

When the finger-type gripping mechanism 23 grips a solid object, the mass of the first article is zero, that is, the first output (Fmz, Faz) may be obtained without gripping the first article. When gripping a bag-packed product with the type gripping mechanism 23, the product Q to be measured is used as the first product, and a plurality of products Q of the same type are used as the second product. In the case of a product that vibrates itself, for example, a bag-packed product or a bottled product, the second output (Fms, Fas) of the second product is obtained and stored for each type.

When storing these basic data (Fmz, Faz, Fms, Fas, known mass, reference mass), the mass measuring device 100 is switched to the setting mode, and in that state, first, the type of the article is input. For example, a product name or a product number is input from the input unit 24 and specified. Next, the reference mass m1 of the first article and the known mass m2 of the second article are input from the input unit 24, and the masses m1 and m2 are stored in the first table 31.
These masses m1 and m2 are previously measured with a precision balance.

Next, the gripping mechanism 23 grips and moves the first article having the reference mass (zero or m1), and stores the first outputs (Fmz, Faz) of the

sensors

21 and 22 at that time. Subsequently, the second article obtained by collecting at least two first articles is gripped and moved, and the second output (Fms, Fas) of each sensor at that time is stored. As a result, the basic data is stored in the first table 31.
Such a setting operation is performed according to an operation guide displayed on the display unit 25. Then, it is programmed so that data is automatically recorded in the first table 31.

The article designating means 28 designates the type of the second article, and is provided in the input unit 24. If the type of the second article is designated by operating the article designating means 28, the first reading means 41 of the designated type is designated. The mass m2 of the second article and its second output (Fms, Fas), and the reference mass m1 of the first article and its first output (Fmz, Faz) are read from the first table 31.

The span coefficient calculation means 42 calculates the span coefficient S by substituting the read basic data (Fmz, Faz, Fms, Fas, reference mass m1, and known mass m2) into the equation (11).

The arithmetic means 43 calculates the span coefficient S, the first output (Fmz, Faz) read from the first table 31, and the

sensors

21 and 22 inputted when the article Q is gripped and moved. The mass m of the article Q is calculated based on the output (Fm, Fa). The calculated mass m is displayed on the display unit 25 and used in a subsequent process. For example, if the measured mass m is less than the reference value, it is used to sort the article Q as a lightweight article.

Second Embodiment
FIG. 12 shows a configuration block diagram of the second embodiment. The storage unit 30 in this figure stores a first span coefficient table 32 as shown in FIG. The first span coefficient table 32 includes the first outputs (Fmz, Faz) of the

sensors

21 and 22 when the gripping mechanism 23 grips and moves the first article having the reference mass m1 including the mass zero and the reference. The mass (zero or m1), the second output (Fms, Fas) of each

sensor

21 and 22 when the gripping mechanism 23 grips and moves the second article having the known mass (m2), and the known mass ( m2) and the first output (Fmz, Faz) and the output ratio (Fmz / Faz) are stored in association with the type of the second article.

In the first embodiment, every time basic data (Fmz, Faz, Fms, Fas, known mass, reference mass) is read, the span coefficient S and the first output ratio (Fmz / Faz) are calculated. In the second embodiment, , There is a difference in that it was asked and memorized in advance. Therefore, when the type of the second article is designated by the article designation means 28, the second reading means 44 reads the span coefficient S of the designated type of the second article and the first output (Fmz, Faz) or its output ratio. (Fmz / Faz) is read from the first span coefficient table 32.

The calculation means 43 includes the read span coefficient S, the first output (Fmz, Faz) or its output ratio (Fmz / Faz), and each sensor input when the article Q is held and moved. Based on the outputs 21 and 22 (Fm, Fa), the mass m of the article Q is calculated. The calculated mass m is displayed on the display unit 25 and used in a subsequent process.

<Third Embodiment>
FIG. 14 shows a configuration block diagram of the third embodiment. The storage unit 30 in this figure stores a second table 33 as shown in FIG. The second table 33 includes the first output (Fmz, Faz) of each

sensor

21 and 22 and the reference when the gripping mechanism 23 grips and moves the first article having the reference mass (m1) including zero. The mass (zero or m1), the second output (Fms, Fas) of each

sensor

21 and 22 when the gripping mechanism 23 grips and moves the second article having the known mass (m2), and the known mass ( m2) is stored in association with different types of gripping mechanisms 23.

The different types of gripping mechanisms 23 are not only the difference between the finger-type gripping mechanism and the air suction type gripping mechanism, but also the same air suction type, depending on the number of suction pads and the difference in suction force, etc. Since the output of each of the

sensors

21 and 22 is affected, the gripping mechanisms that have such effects are different types of gripping mechanisms.

When the basic data (Fmz, Faz, Fms, Fas, known mass, reference mass) is stored in the second table 33, after switching to the setting mode, the type of the gripping mechanism 23 is set according to the type of article, for example, , Type A, type B, etc. Thereafter, as in the case of the first embodiment, if the basic data (Fmz, Faz, Fms, Fas, known mass, reference mass) is stored, the second table 33 is completed.
When the finger type is used as the gripping mechanism 23 and the mass is zero as the first article, that is, when nothing is gripped, the first article is used as the second article and the mass is input as the known mass. .

The gripping mechanism designating means 29 designates the type of the gripping mechanism 23 that is mounted. When the type of the gripping mechanism 23 is designated in this way, the third reading unit 45 obtains each output (Fmz, Faz, Fms, Fas) corresponding to the designated type of the gripping mechanism 23, and the reference mass and the known mass. Read from the second table 33.

The span coefficient calculation means 42 calculates the span coefficient S by substituting the read basic data (Fmz, Faz, Fms, Fas, reference mass m1, and known mass m2) into the equation (11).
The calculation means 43 grips and moves the calculated span coefficient S, the first output (Fmz, Faz) or its output ratio (Fmz / Faz) read from the first table 31, and the article Q. The mass m of the article Q is calculated based on the outputs (Fm, Fa) of the

sensors

21 and 22 input during Others are the same as the first embodiment.

<Fourth embodiment>
FIG. 16 shows a configuration block diagram of the fourth embodiment. The storage unit 30 in this figure stores a second span coefficient table 34 as shown in FIG. The second span coefficient table 34 includes a first output (Fmz,) of the

sensors

21 and 22 when the gripping mechanism 23 grips and moves a first article having a reference mass (zero or m1) including zero. Faz), its reference mass (zero or m1), and the second output (Fms, Fas) of each

sensor

21, 22 when the gripping mechanism 23 grips and moves the second article of known mass (m2). And the span coefficient S calculated based on the known mass (m2) and the first output (Fmz, Faz) or its output ratio (Fmz / Faz) in association with different types of gripping mechanisms 23. It is.

In the third embodiment, the span coefficient S is calculated every time basic data (Fmz, Faz, Fms, Fas, known mass, reference mass) is read. In the fourth embodiment, the span coefficient and the first output ratio ( There is a difference in that Fmz / Faz) is obtained and stored in advance. Therefore, when the type of the gripping mechanism 23 is specified by the gripping mechanism specifying means 29, the fourth reading means 46 outputs the span coefficient S corresponding to the specified gripping mechanism 23 and the first output (Fmz, Faz) or its output. The ratio (Fmz / Faz) is read from the second span coefficient table 34.

When the calculation means 43 grips and moves the read span coefficient S, the first output (Fmz, Faz) or its output ratio (Fmz / Faz), and the article Q in the same manner as described above. The mass m of the article Q is calculated on the basis of the outputs (Fm, Fa) of the

sensors

21 and 22 input to.

<Fifth Embodiment>
FIG. 18 shows a configuration block diagram of the fifth embodiment. In the storage unit 30 in this figure, a third table 35 as shown in FIG. 19 is stored. The third table 35 includes the first outputs (Fmz, Faz) of the

sensors

21 and 22 and the reference when the gripping mechanism 23 grips and moves the first article having the reference mass (m1) including zero. The second output (Fms, Fas) of each

sensor

21 and 22 when the gripping mechanism 23 grips and moves the second article of different known mass (m2), and the mass (zero or m1) The known mass (m2) is stored corresponding to the type of the second article and also corresponding to the gripping mechanisms 23 of different types.
In FIG. 19, the type C gripping mechanism 23 is a finger type, and in this case, the first output (Fmz, Faz) is obtained without gripping the first article.

The fifth embodiment is a combination of the first embodiment and the third embodiment. In particular, the basic data (Fmz, Faz, Fms, Fas, known mass, reference mass) is made to correspond to the type of the second article. In addition, there is a difference in the points stored corresponding to different types of gripping mechanisms 23. Therefore, in use, the type of the second article is designated by the article designation means 28 and the type of the gripping mechanism 23 to be used by the gripping mechanism designation means 29 is designated. Then, the fifth reading means 47 reads basic data (Fmz, Faz, Fms, Fas, known mass, reference mass) corresponding to the designated gripping mechanism and the second article from the third table 35. For example, when the gripping mechanism 23 is designated as type A and the type of the article Q is designated as N0.2, basic data (Fmz, Faz, Fms, Fas, known mass, reference mass) surrounded by a thick line in FIG. Read from the third table 35.

The span coefficient calculation means 42 calculates the span coefficient S by substituting the read basic data (Fmz, Faz, Fms, Fas, reference mass m1 and known mass m2) into the above equation (11), as described above. To do.
The arithmetic means 43 calculates the span coefficient S, the first output (Fmz, Faz) read from the third table 35, and the sensors 21 input when the article Q is gripped and moved. , 22 based on the outputs (Fm, Fa), the mass m of the article Q is calculated.

<Sixth Embodiment>
FIG. 20 shows a configuration block diagram of the sixth embodiment. The storage unit 30 in this figure stores a third span coefficient table 36 as shown in FIG. The table 36 includes a first output (Fmz, Faz) of each of the

sensors

21 and 22 and a reference mass (zero) when the gripping mechanism 23 grips and moves the first article having the reference mass m1 including the mass zero. Or m1), and the second output (Fms, Fas) of each

sensor

21 and 22 and the known mass (m2) when the gripping mechanism 23 grips and moves the second article having the known mass m2. The span coefficient S for each type of the second article calculated as described above is stored in association with the different types of gripping mechanisms 23 together with the first output (Fmz, Faz) and the output ratio (Fmz / Faz). .
In FIG. 21, the type C gripping mechanism 23 is a finger type, and in this case as well, as in FIG. 19, the first output (Fmz, Faz) is obtained without gripping the first article.

In the fifth embodiment, the span coefficient S is calculated every time basic data (Fmz, Faz, Fms, Fas, known mass, reference mass) is read. In the sixth embodiment, the span coefficient S and the first output ratio are calculated. There is a difference in that (Fmz / Faz) is obtained and stored in advance. Therefore, when the type of the article is designated by the article designation means 28 and the kind of the gripping mechanism 23 is designated by the gripping mechanism designation means 29, the sixth reading means 48 designates the designated type of article. The span coefficient S and the first output ratio (Fmz / Faz) corresponding to the type of gripping mechanism 23 are read from the third span coefficient table 36. Others are the same as in the third embodiment.

<Seventh embodiment>
FIG. 22 shows a configuration block diagram of the seventh embodiment. This block diagram has the same basic configuration as that of FIG. 8, but is different in that a warning means 60 is newly provided in the display unit 25. This warning means 60 is the operation mode of the moving mechanism 11 when acquiring the basic data (Fmz, Faz, Fms, Fas, reference mass, known mass), and when the article Q is actually gripped and moved. An alarm is issued when the operation mode is different from the operation mode, thereby preventing an error caused by the difference in the operation mode.

Therefore, each time the new operation mode of the moving mechanism 11 is set or changed in the setting mode, the basic data (Fmz, Faz, Fms, Fas, reference mass, known mass) is read again. The warning means 60 displays a message. If the operation mode is changed without doing so, the warning means 60 issues a warning. Thereby, a measurement error can be suppressed.

<Eighth Embodiment>
FIG. 23 shows a configuration block diagram of the eighth embodiment. This block diagram has the same basic configuration as that of FIG. 22, but differs from the seventh embodiment in that a fourth table 37 is provided in the storage unit 30.

The fourth table 37 stores the operation mode set in the moving mechanism 11 and the tables 31 to 36 acquired under the operation mode in association with each other, and an example is shown in FIG. In FIG. 24, for example, the first, second, and third tables are registered as tables acquired under the operation mode of mode 1. Therefore, the operation mode is switched to mode 2, and even if an attempt is made to measure the mass of an article having an unknown mass from the second table under mode 2, the second table is not registered under mode 2, so the warning means 60 warns that the basic data is re-taken.

When the basic data of the second table is acquired under mode 2 based on the warning, the second table is registered in mode 2 in the fourth table. After that, since the second table can be accessed under mode 2, the operation can be continued even if the operation mode is switched.

As described above, according to the present invention, since the mass of an article can be measured more accurately while the article is moved by a robot hand, the present invention can be used in a field where an industrial robot is used.

DESCRIPTION OF SYMBOLS 1 Force sensor 2 Grip mechanism 3 Movement mechanism 4 Acceleration sensor 11 Movement mechanism 12 Tip base part 21 Force sensor 22 Acceleration sensor 23 Grip mechanism 28 Article designation means 29 Grip mechanism designation means 31 First table 32 First span coefficient table 33 Second Table 34 Second span coefficient table 35 Third table 36 Third span coefficient table 37 Fourth table 41 First reading means 42 Span coefficient calculating means 43 Computing means 44 Second reading means 45 Third reading means 46 Fourth reading means 47 5th reading means 48 6th reading means 60 Warning means Q Goods

Claims

A mass measuring device that measures the mass of an article from the force and acceleration acting on the article while the speed of the article is changing,
A gripping mechanism for gripping the article;
A moving mechanism for moving the gripping mechanism;
A force sensor that is provided between the gripping mechanism and the moving mechanism and detects a force acting on the article while the speed is changing;
An acceleration sensor that is provided between the gripping mechanism and the moving mechanism and detects an acceleration acting on the article while the speed is changing;
The first output (Fmz, Faz) of each sensor and the reference mass when the first article having the reference mass including zero mass is moved while changing the speed, and the type of the gripping mechanism The second output (Fms, Fas) of each sensor and the known mass when the second article having a different known mass is moved while changing its speed are stored in correspondence with the type of the second article. The first table;
Article designating means for designating the type of the second article;
The known mass and its second output (Fms, Fas) corresponding to the specified type of the second article, and the reference mass of the first article and its first output (Fmz, Faz) are stored in the first table. Reading from the first reading means;
A span coefficient calculating means for calculating a span coefficient based on each read output (Fmz, Faz, Fms, Fas) and the known mass and the reference mass;
The article of unknown mass based on the calculated span coefficient, the read first output (Fmz, Faz), and the output of each sensor when the specified kind of article is gripped and moved Computing means for calculating the mass of
A mass measuring apparatus comprising:
A mass measuring device that measures the mass of an article from the force and acceleration acting on the article while the speed of the article is changing,
A gripping mechanism for gripping the article;
A moving mechanism for moving the gripping mechanism;
A force sensor that is provided between the gripping mechanism and the moving mechanism and detects a force acting on the article while the speed is changing;
An acceleration sensor that is provided between the gripping mechanism and the moving mechanism and detects an acceleration acting on the article while the speed is changing;
The first output (Fmz, Faz) of each sensor and the reference mass when the first article having the reference mass including zero mass is moved while changing the speed, and the type of the gripping mechanism Span coefficients calculated based on the second outputs (Fms, Fas) of the sensors and the known masses when the second articles having different known masses are moved while changing their speeds, are used as the first output. (Fmz, Faz) or its output ratio (Fmz / Faz) together with the first span coefficient table stored corresponding to the type of the second article,
Article designating means for designating the type of the second article;
Second reading means for reading a span coefficient corresponding to the second article of the specified type and the first output (Fmz, Faz) or its output ratio (Fmz / Faz) from the first span coefficient table. When,
The read span coefficient, the first output (Fmz, Faz) or its output ratio (Fmz / Faz), and the output of each sensor when a specified type of article is held and moved. A computing means for calculating the mass of the article of unknown mass based on:
A mass measuring apparatus comprising:
A mass measuring device that measures the mass of an article from the force and acceleration acting on the article while the speed of the article is changing,
A gripping mechanism for gripping the article;
A moving mechanism for moving the gripping mechanism;
A force sensor that is provided between the gripping mechanism and the moving mechanism and detects a force acting on the article while the speed is changing;
An acceleration sensor that is provided between the gripping mechanism and the moving mechanism and detects an acceleration acting on the article while the speed is changing;
The first output (Fmz, Faz) of each sensor and its reference mass when the first article having a reference mass including zero mass is moved while changing the speed thereof, and the gripping mechanism are known. A second table in which the second output (Fms, Fas) of each sensor and its known mass when the second article of mass is moved while changing its speed are stored in association with different types of gripping mechanisms. When,
A gripping mechanism designating means for designating a type of the gripping mechanism to be used;
A third readout means for reading out each output (Fmz, Faz, Fms, Fas) corresponding to the designated type of gripping mechanism, as well as a reference mass and a known mass, from the second table;
A span coefficient calculation means for calculating a span coefficient based on each read output (Fmz, Faz, Fms, Fas) and a known mass and a reference mass;
Based on the calculated span coefficient, the read first output (Fmz, Faz), and the output of each sensor when the article is gripped and moved, the mass of the article having an unknown mass is calculated. Calculating means,
A mass measuring apparatus comprising:
A mass measuring device that measures the mass of an article from the force and acceleration acting on the article while the speed of the article is changing,
A gripping mechanism for gripping the article;
A moving mechanism for moving the gripping mechanism;
A force sensor that is provided between the gripping mechanism and the moving mechanism and detects a force acting on the article while the speed is changing;
An acceleration sensor that is provided between the gripping mechanism and the moving mechanism and detects an acceleration acting on the article while the speed is changing;
The first output (Fmz, Faz) of each sensor and its reference mass when the first article having a reference mass including zero mass is moved while changing the speed thereof, and the gripping mechanism are known. The span coefficient calculated based on the second output (Fms, Fas) of each sensor and its known mass when the second article of mass is moved while changing its speed is the first output (Fmz, Faz) or its output ratio (Fmz / Faz), and a second span coefficient table stored corresponding to different types of gripping mechanisms;
A gripping mechanism designating means for designating a type of the gripping mechanism to be used;
A fourth reading means for reading a span coefficient corresponding to a specified type of gripping mechanism and the first output or its output ratio from the second span coefficient table;
Calculation means for calculating the mass of the article having an unknown mass based on the read span coefficient, the first output or its output ratio, and the output of each sensor when the article is gripped and moved When,
A mass measuring apparatus comprising:
A mass measuring device that measures the mass of an article from the force and acceleration acting on the article while the speed of the article is changing,
A gripping mechanism for gripping the article;
A moving mechanism for moving the gripping mechanism;
A force sensor that is provided between the gripping mechanism and the moving mechanism and detects a force acting on the article while the speed is changing;
An acceleration sensor that is provided between the gripping mechanism and the moving mechanism and detects an acceleration acting on the article while the speed is changing;
The first output (Fmz, Faz) of each sensor and the reference mass when the first article having the reference mass including zero mass is moved while changing the speed, and the type of the gripping mechanism The second output (Fms, Fas) and the known mass of each sensor when the second article having a different known mass is moved while changing its speed correspond to the type of the second article. A third table stored corresponding to different gripping mechanisms;
A gripping mechanism designating means for designating the type of gripping mechanism to be used;
Article designating means for designating a type of the second article to be gripped by the designated type of gripping mechanism;
Fifth reading means for reading each output (Fmz, Faz, Fms, Fas) corresponding to the gripping mechanism designated by each designation means and the second article, and the reference mass and the known mass from the third table. When,
A span coefficient calculation means for calculating a span coefficient based on each read output (Fmz, Faz, Fms, Fas) and a known mass and a reference mass;
Unknown based on the calculated span coefficient, the read first output (Fmz, Faz) or its output ratio (Fmz / Faz), and the output of each sensor when the article is held and moved Computing means for calculating the mass of the article of mass;
A mass measuring apparatus comprising:
A mass measuring device that measures the mass of an article from the force and acceleration acting on the article while the speed of the article is changing,
A gripping mechanism for gripping the article;
A moving mechanism for moving the gripping mechanism;
A force sensor that is provided between the gripping mechanism and the moving mechanism and detects a force acting on the article while the speed is changing;
An acceleration sensor that is provided between the gripping mechanism and the moving mechanism and detects an acceleration acting on the article while the speed is changing;
The first output (Fmz, Faz) of each sensor and the reference mass when the first article having the reference mass including zero mass is moved while changing the speed, and the type of the gripping mechanism For each type of the second article calculated based on the second output (Fms, Fas) of each sensor and its known mass when the second article having a different known mass is moved while changing its speed. A third span coefficient table storing the span coefficient in association with different types of gripping mechanisms together with the first output (Fmz, Faz) or its output ratio (Fmz / Faz);
A gripping mechanism designating means for designating the type of gripping mechanism to be used;
Article designating means for designating a type of the second article to be gripped by the designated type of gripping mechanism;
Sixth reading means for reading from the third span coefficient table the span coefficient corresponding to the gripping mechanism designated by each designation means and the second article, and the first output or its output ratio;
The read span coefficient, the first output (Fmz, Faz) or its output ratio (Fmz / Faz), and the output of each sensor when a specified type of article is held and accelerated. A computing means for calculating the mass of the article of unknown mass based on:
A mass measuring apparatus comprising:
In the mass measuring device in any one of Claims 1-6,
The operation mode of the moving mechanism when the first output (Fmz, Faz) and the second output (Fms, Fas) are obtained from each sensor, and the operation of the moving mechanism when measuring the mass of an article of unknown mass When the mode is different, warning means for warning that each of the outputs (Fmz, Faz, Fms, Fas) is retaken under a new operation mode;
A mass measuring apparatus characterized by comprising:
A fourth table that stores the operation mode set in the moving mechanism in association with each table created under the operation mode;
The mass measuring device according to claim 7, further comprising: