A robot system includes a robot that self-travels along a traveling shaft and is provided with a position detection sensor at a distal end, a support member that has a plurality of reference positions juxtaposed and supports a workpiece, a plurality of calibration members that are juxtaposed along the traveling shaft, and a control device, in which the calibration members each have a calibration position, and the control device is configured to cause the robot to move by a predetermined first distance along the traveling shaft, calibrate position coordinates of the robot based on position coordinates of the calibration positions detected by the position detection sensor, and subsequently calibrate position coordinates of the workpiece based on position coordinates of the reference positions detected by the position detection sensor.

A device for acquiring a position and orientation of an end effector of a robot is provided. The robot has a robot arm with axes coupled to one another by joints. The end effector is arranged on an end of the robot arm, optical markers are arranged on first and second axes, and a number of joints between the end effector and the first axis is lower than a number of joints between the end effector and the second axis. An optical sensor acquires image data of the optical markers. A storage device stores a kinematic model of the robot arm. An evaluation device, in a first case, determines a first position of a first optical marker and the position and orientation of the end effector and, in a second case, a second position of a second optical marker and the position and orientation of the end effector.

A positioning system using a robot, capable of eliminating an error factor of the robot such as thermal expansion or backlash can be eliminated, and carrying out positioning of the robot with accuracy higher than inherent positioning accuracy of the robot. The positioning system has a robot with a movable arm, visual feature portions provided to a robot hand, and vision sensors positioned at a fixed position outside the robot and configured to capture the feature portions. The hand is configured to grip an object on which the feature portions are formed, and the vision sensors are positioned and configured to capture the respective feature portions.

A robot control method of controlling motion of a robot arm by using a servo motor includes adding d-axis electric current to a motor electric current command (steps 15-6, 15-8) if external temperature is less than or equal to a predetermined value (step 15-3), and if an absolute value of the motor electric current command is less than or equal to a predetermined value (step 15-4), and if a value of detected overload is less than or equal to a predetermined value (step 15-5).

A thermal compensation control system for a machine tool having a milling cutter and a cutter driver includes a tool setting probe, a temperature sensor, a workpiece touch probe, and a controller. The cutter driver is connected to the milling cutter to drive the milling cutter to process the work piece based on a control signal. The tool setting probe is configured to detect a cutter length of the milling cutter. The temperature sensor is configured to sense a measured temperature of the cutter driver or the milling cutter. The workpiece touch probe is configured to measure processing errors of the processed work piece. The controller is configured to generate the control signal based on a processing instruction, a temperature compensation model, the cutter length, and the measured temperature. The controller is further configured to determine whether to modify the temperature compensation model based on the processing errors.

The present disclosure is directed toward a method that includes logging offset data of a machine over a period of operational time having varying thermal conditions, comparing the logged offset data against a thermal model, estimating offsets for the machine based on the comparing, and adjusting offsets of the machine during operation.

The present disclosure generally describes a method for processing a workpiece in a machine, where the method determines an offset of the machine and adjusts for the offset during production operation. In one form, the method includes logging offset data of the machine over a period of operational time having varying thermal conditions, and comparing the logged offset data against a thermal model, where the thermal model is generated based on a probing routine and dry cycling for a plurality of test cycles on a calibration artifact. Based on the comparing, the method estimates offsets for the machine and adjusts offsets of the machine during operation.

A thermal compensation control system for a machine tool having a milling cutter and a cutter driver includes a tool setting probe, a temperature sensor, a workpiece touch probe, and a controller. The cutter driver is connected to the milling cutter to drive the milling cutter to process the work piece based on a control signal. The tool setting probe is configured to detect a cutter length of the milling cutter. The temperature sensor is configured to sense a measured temperature of the cutter driver or the milling cutter. The workpiece touch probe is configured to measure processing errors of the processed work piece. The controller is configured to generate the control signal based on a processing instruction, a temperature compensation model, the cutter length, and the measured temperature. The controller is further configured to determine whether to modify the temperature compensation model based on the processing errors.

A controlling unit obtains an error in position and orientation of each joint of a robot. The controlling unit uses an error component in a driving direction of an actuator included in the error in position and orientation u.sub.i of the joint to obtain a first correction quantity, to obtain a residual error excluding the error component in the driving direction of the actuator from the error in position and orientation of the joint, and to obtainan error in position and orientation of the end point of the robot based on the residual error of each joint. The controlling unit uses the error in position and orientation of the joint based on the error in position and orientation of the end point of the robot to obtain a second correction quantity q.sub.i, and uses the first correction quantity and the second correction quantity to correct a joint instruction value.

The present disclosure generally describes a method for processing a workpiece in a machine, where the method determines an offset of the machine and adjusts for the offset during production operation. In one form, the method includes logging offset data of the machine over a period of operational time having varying thermal conditions, and comparing the logged offset data against a thermal model, where the thermal model is generated based on a probing routine and dry cycling for a plurality of test cycles on a calibration artifact. Based on the comparing, the method estimates offsets for the machine and adjusts offsets of the machine during operation.