Method for transmitting information in controller and method for detecting abnormality in encoder

A method for transmitting information from a controller included in an operating device, the operating device further including:

• a robot arm having an output shaft;
• a motor connected to the output shaft;
• an encoder configured to detect a rotational position of the motor;
• a driver configured to receive
• first and second speed commands from the controller, and
• an output signal from the encoder,
• the driver being configured to control driving of the motor based on the output signal and at least one of the first and second speed commands;
• and
• a fault detection unit configured to detect a fault in the encoder,
• the controller being configured to output
• the first speed command indicating the rotational position of the motor, the first speed command being generated based on teaching program information,
• the second speed command when the driver performs fast response control, the fast response control being control performed by the driver in parallel with a normal control when the robot arm is suddenly raised or pulled down, and
• commanded-position information showing the rotational position indicated by the first speed command,
• the method comprising:
• generating, by the controller, the second speed command for the fast response control;
• transmitting the first speed command and the second speed command from the controller to the driver;
• generating, by the driver, control information to control the rotation of the motor based on the first speed command, the second speed command, and the output signal of encoder;
• transmitting the control information generated by the driver to the controller;
• converting, by the controller, the control information into an amount-of-movement of the output shaft, the amount-of-movement being a rotation angle of the motor in a clockwise or a counterclockwise direction;
• generating, by the controller, new commanded-position information by adding the amount-of-movement to the commanded-position information;
• and
• transmitting the new commanded-position information to the fault detection unit.