Patent ID: 9140598
Filing Date: 2015-09-22
Classification: B25J,G01G,G01L,G05B

Abstract:
1. A mass measurement device for measuring a mass of an article while the article is in motion, the mass measurement device comprising: a movement mechanism; a force sensor fixedly attached to a distal end of the movement mechanism for movement therewith; a holding mechanism fixedly attached to the force sensor, and configured to grab and hold the article and move the article in response to movement operations of the movement mechanism, the force sensor being configured to measure a force acting on the article during movement and output corresponding force measurement data; an acceleration sensor fixedly attached to the holding mechanism for movement therewith and configured to measure acceleration acting on the article during movement and configured to output acceleration data; and a control circuit configured to operatively control the holding mechanism and the movement mechanism, and calculate the mass of the article on the basis of the force measurement data and the acceleration data, the control circuit being configured to conduct a first mass measurement dividing the force measurement data acting on the article acquired during a single movement of the article by the acceleration data acting on the article acquired during the single movement in order to calculate the mass of the article; the control circuit being configured to conduct a second mass measurement of the article during the single movement at a different time from the first mass measurement, the control circuit including determining a vertical force acting on the article from the force measurement data acquired at the different time and determining gravitational acceleration from the acceleration data at the different time, the second mass measurement including dividing the vertical force acting on the article by the gravitational acceleration while the article is held by the holding mechanism during the single movement in order to calculate the mass of the article; and the control circuit being configured to determine mass of the object using the second mass measurement when a predetermined condition holds true, the predetermined condition being that the output of the first acceleration measurement must be less than a predetermined value such that a maximum output of the first acceleration measurement is less than a predetermined threshold value.