A method of determining a joint torque in a joint of an articulated industrial robot, the robot having a first arm and a second arm which are coupled to each other by the joint and which are movable relative to each other by an electric drive unit coupled to the first and second arm, includes: controlling the electric drive unit by an electronic control device; assigning a measuring device to the electric drive unit, the measuring device measuring an electric current supplied to the drive unit; determining an actual value of the torque which is applied to the second arm from the measured electric current; and comparing, using the electronic control device, the determined actual torque value with a predetermined desired torque value for the joint.

A monitoring device of a robot system includes: an external force detecting portion configured to detect external force acting on a robot; an area determining portion configured to determine whether or not a predetermined portion of the robot is located within a predetermined area; a force monitoring portion configured to detect collision of the robot based on a first monitoring criterion including at least monitoring of the external force acting on the robot, and when the area determining portion determines that the predetermined portion of the robot is not located within the predetermined area, detect the collision based on a second monitoring criterion not including the monitoring of the external force; and a stop signal generating portion configured to, when the force monitoring portion detects the collision, generate a stop signal of the robot 2 and supply the stop signal to the control device.

There are provided a load state diagnosis device and a load state diagnosis method for a servomotor. A PLC diagnoses the load state of the servomotor which rotationally drives a rotary tool in a predetermined rotational drive direction at a constant speed. The PLC includes a detection part that detects the rotational direction of a torque acting on the servomotor, a determination part that determines whether the rotational direction of the torque detected by the detection part is consistent with the predetermined rotational drive direction, and a load index output part that outputs a load index indicating the load state of the servomotor based on a determination result of the determination part.

A monitoring device of a robot system includes: an external force detecting portion configured to detect external force acting on a robot; an area determining portion configured to determine whether or not a predetermined portion of the robot is located within a predetermined area; a force monitoring portion configured to detect collision of the robot based on a first monitoring criterion including at least monitoring of the external force acting on the robot, and when the area determining portion determines that the predetermined portion of the robot is not located within the predetermined area, detect the collision based on a second monitoring criterion not including the monitoring of the external force; and a stop signal generating portion configured to, when the force monitoring portion detects the collision, generate a stop signal of the robot 2 and supply the stop signal to the control device.

An actuator (1) comprises an electric motor (11) for moving an actuated part (2) to an actuated position. The actuator (1) further comprises a controller (10) connected to the electric motor (11) and configured to determine a motor current of the electric motor (11) and to detect motor rotations. The controller (10) is further configured to determine the actuated position by counting the motor rotations detected while the motor current is at or above a current threshold indicative of a load torque, and by not counting motor rotations detected while the motor current is below said current threshold.

An actuator (1) comprises an electric motor (11) for moving an actuated part (2) to an actuated position. The actuator (1) further comprises a controller (10) connected to the electric motor (11) and configured to determine a motor current of the electric motor (11) and to detect motor rotations. The controller (10) is further configured to determine the actuated position by counting the motor rotations detected while the motor current is at or above a current threshold indicative of a load torque, and by not counting motor rotations detected while the motor current is below said current threshold.

A linear transfer system for a collaborative robot includes a linear bearing extending along a linear axis. A carriage on the linear bearing moves along the linear axis and supports a collaborative robot. One or more load cells are supported on either axial end of the carriage. A motor causes movement of the carriage along the linear axis under the control of a motor control circuit. The circuit receives input signals indicative of forces applied to the load cells. During a programming mode for the system, the circuit may generate control signals for the motor causing movement of the carriage along the linear axis corresponding to the forces applied to the load cells. During an operating mode of the system, the circuit may detect collisions by comparing the forces to a threshold and generating control signals to halt movement of the carriage if a predetermined condition is met.