Multi-joint robot having gas spring, and method for estimating inner pressure of the gas spring
AssigneeFanuc Corporation
InventorYu Hayashi
Life of this patent
Estimating the term…
Abstract
A multi-joint robot having a function for estimating an amount of decrease in inner pressure of a gas spring, by means of a simple and low-cost structure, and a method for estimating the amount of decrease in inner pressure of the gas spring. The gas pressure within a cylinder of the gas spring decreases in connection with the motion of a lower arm associated with the gas spring. In the present invention, in view of a finding that the amount of decrease in inner pressure has a high correlation with a total movement distance obtained by integrating an amount of back-and-forth motion of a piston rod relative to a cylinder, an amount of decrease in inner pressure within the gas spring is estimated by calculating the total movement distance.
Claims5
A multi-joint robot comprising:
- a robot mechanical unit having at least one arm;
- a gas spring arranged on the arm;
- and
- a controller which controls the robot mechanical unit,
- wherein the gas spring comprises a cylinder, compressible inert gas enclosed within the cylinder and a piston rod configured to slide in the cylinder, the gas spring being configured as a gas balancer for reducing a load of a servomotor which drives the arm, and
- wherein the controller has a function to calculate a total movement distance of the piston rod by integrating an amount of back-and-forth motion of the piston rod relative to the cylinder, and calculate an amount of decrease in inner pressure of the compressible inert gas based on the total movement distance.
A method for estimating an amount of decrease in inner pressure of a gas spring of a multi-joint robot, the multi-joint robot comprising:
- a robot mechanical unit having at least one arm;
- a gas spring arranged on the arm;
- and
- a controller which controls the robot mechanical unit,
- wherein the gas spring comprises a cylinder, compressible inert gas enclosed within the cylinder and a piston rod configured to slide in the cylinder, the gas spring being configured as a gas balancer for reducing a load of a servomotor which drives the arm, and
- wherein the method comprising the steps of:
- calculating a total movement distance of the piston rod by integrating an amount of back-and-forth motion of the piston rod relative to the cylinder;
- and
- calculating an amount of decrease in inner pressure of the compressible inert gas based on the total movement distance.
Dependencies are inferred from the claim text.