Weight measurement system and method using robot

Patent metadata

Field	Value
Publication number	US-10180346-B2
Application number	US-201715401518-A
Country	US
Kind code	B2
Filing date	Jan 9, 2017
Priority date	Jan 13, 2016
Publication date	Jan 15, 2019
Grant date	Jan 15, 2019

Abstract

A weight measurement system and a weight measurement method using a robot, by which a weight greater than a weight capacity of the robot can be measured. The system has a robot, a robot controller for controlling the motion of the robot, and an arithmetic processing unit for calculating the weight of an article to be measured. The robot is configured to apply a force to a working point connected to a tank so that at least one of support points or a part of a support surface of the tank is lifted, and simultaneously, the remaining support point or the remaining part of the support surface of the tank is grounded. The weight of the tank containing processing fluid can be measured based on a relationship between the force applied to the working point by the robot and a lever ratio.

First claim

The invention claimed is:

1. A weight measurement system for measuring a weight of an article to be measured by using a robot and a lever, the weight being supported by a plurality of grounded support points or at least one grounded support surface of the article,
wherein the robot is configured to push-down one end of the lever so as to lift a working point of the article mounted on the other end of the lever so that at least one of the support points or a part of the support surface of the article is lifted, and simultaneously, the remaining support point or the remaining part of the support surface of the article is grounded,
and wherein the weight measurement system comprises an arithmetic processing unit configured to: calculate a magnitude of a force applied to the working point based on a load of a motor provided to the robot; and calculate the weight of the article based on the magnitude of the force and a positional relationship among the working point, the remaining support point or the remaining part of the support surface, and a center of gravity of the article.

2. The weight measurement system as set forth in claim 1 , wherein the weight measurement system comprises a means for detecting a position of the working point, and a means for sensing that the at least one of the support point or the part of the support surface of the article is lifted, based on the position of the working point.

3. The weight measurement system as set forth in claim 1 , wherein the weight measurement system comprises a means for outputting an alarm or a signal to outside when the load of the motor exceeds or falls below a predetermined threshold which is not more than an upper limit of the load of the motor.

4. The weight measurement system as set forth in claim 1 , wherein, when the position of the support point or the support surface relative to the working point is unchangeable, the arithmetic processing unit calculates the weight of the article by a proportional calculation based on the load of the motor.

5. The weight measurement system as set forth in claim 1 , wherein the article is a tank containing liquid, and the arithmetic processing unit calculates a weight of the liquid by subtracting a weight of the tank in an empty state from the weight of the article.

6. A weight measurement method for measuring a weight of an article to be measured by using a robot and a lever, the weight being supported by a plurality of grounded support points or at least one grounded support surface of the article, the method comprising the steps of:
pushing-down one end of the lever so as to lift a working point of the article mounted on the other end of the lever so that at least one of the support points or a part of the support surface of the article is lifted, and simultaneously, the remaining support point or the remaining part of the support surface of the article is grounded;
calculating a magnitude of a force applied to the working point based on a load of a motor provided to the robot; and
calculating the weight of the article based on the magnitude of the force and a positional relationship among the working point, the remaining support point or the remaining part of the support surface, and a center of gravity of the article.

Assignees

• Fanuc Corp

Inventors

• Ebihara Kenzo
• Ooki Takeshi

Classifications

• G01G19/52 Primary

  Weighing apparatus combined with other objects, e.g. furniture (with walking sticks A45B3/08) · CPC title

• G01G23/36

  Indicating the weight by electrical means, e.g. using photoelectric cells · CPC title

• G01G19/00

  Weighing apparatus or methods adapted for special purposes not provided for in the preceding groups {(electric measuring arrangements involving comparison with a reference value G01R17/00)} · CPC title

• B25J19/00 Primary

  Accessories fitted to manipulators, e.g. for monitoring, for viewing; Safety devices combined with or specially adapted for use in connection with manipulators (safety-devices in general F16P; protection against radiation in general G21F) · CPC title