US Patent No. 9,102,064

MULTI-JOINT ROBOT HAVING GAS SPRING, AND METHOD FOR ESTIMATING INNER PRESSURE OF THE GAS SPRING


Patent No. 9,102,064
Issue Date August 11, 2015
Title Multi-joint Robot Having Gas Spring, And Method For Estimating Inner Pressure Of The Gas Spring
Inventorship Yu Hayashi, Yamanashi (JP)
Assignee Fanuc Corporation, Yamanashi (JP)

Claim of US Patent No. 9,102,064

1. 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.