Robot control device and robot system

A robot control device that controls an operation of a robot including a first arm, a second arm, a first joint connecting between the first and second arms, a motor configured to drive the first arm relative to the second arm based on an operation command value, and first and second encoders disposed in the first joint, the first and second encoders being configured to detect an operation of the motor and output first and second encoder values, respectively, the robot control device comprising:

• a first arithmetic processor configured to be programed to compare between the operation command value and the first encoder value and output a first command value comparison result;
• a second arithmetic processor, different from the first arithmetic processor, configured to be programed to compare between the operation command value and the second encoder value and output a second command value comparison result;
• and
• a power interrupter configured to interrupt power of the motor based on at least one of a first interruption signal and a second interruption signal, wherein
• when the first arithmetic processor is further configured to be programed to determine that the first command value comparison result and the second command value comparison result are the same, the power interrupter does not interrupt the power of the motor based on the first interruption signal,
• when the first arithmetic processor is further configured to be programed to determine that the first command value comparison result and the second command value comparison result are different, the power interrupter interrupts the power of the motor based on the first interruption signal,
• when the second arithmetic processor is further configured to be programed to determine that the first command value comparison result and the second command value comparison result are the same, the power interrupter does not interrupt the power of the motor based on the second interruption signal, and
• when the second arithmetic processor is further configured to be programed to determine that the first command value comparison result and the second command value comparison result are different, the power interrupter interrupts the power of the motor based on the second interruption signal.