Gas pressure detection device, robot having gas pressure detection device, and gas pressure detection method of the same

A robot, comprising an arm supporting part, a rotary arm rotatably supported by the arm supporting part, a gas balancer configured to reduce a rotational load of the rotary arm, a pressure sensor configured to measure a pressure of gas in the gas balancer, and a gas pressure detection device configured to detect a decrease in the pressure of the gas of the gas balancer,

• wherein the gas pressure detection device includes:
• a calculating part configured to calculate a parameter Rt(θ) indicating a magnitude relation between a reference pressure Pa(θ) at a rotational angle θ of the rotary arm and a measured pressure Pt(θ) measured at the rotational angle θ by the pressure sensor, calculate a plurality of parameters Rt(θ) based on a plurality of measured pressures Pt(θ) at different measurement times, and calculate a moving average Rtj(θ) of the parameter Rt(θ) at a measurement time tj that is a j-th measurement time of the measured pressure Pt(θ), j representing a natural number of 2 or above;
• a determining part configured to compare the moving average Rtj(θ) with a reference value R to detect the decrease in the pressure of the gas;
• and
• a stopping part configured to stop the robot when the moving average Rtj(θ) is below the reference value R.

A method of detecting a decrease in a pressure of gas of a gas balancer provided to a robot having an arm supporting part, a rotary arm rotatably supported by the arm supporting part, and a pressure sensor configured to measure the pressure of the gas of the gas balancer, the gas balancer being configured to reduce a rotational load of the rotary arm, the method comprising the steps of:

• (A) measuring the pressure of the gas of the gas balancer by the pressure sensor to acquire a measured pressure Pt(θ) at a rotational angle θ of the rotary arm;
• (B) calculating a parameter Rt(θ) indicating a magnitude relation between the measured pressure Pt(θ) and a reference pressure Pa(θ) at the rotational angle θ of the rotary arm;
• (C) calculating a plurality of parameters Rt(θ) based on a plurality of measured pressures Pt(θ) at different measurement times, and calculating a moving average Rtj(θ) of the parameter Rt(θ) at a measurement time tj that is a j-th measurement time of the measured pressure Pt(θ), j representing a natural number of 2 or above;
• (D) comparing the moving average Rtj(θ) with a reference value R to detect the decrease in the pressure of the gas;
• and
• (E) stopping the robot when the moving average Rtj(θ) is below the reference value R.