A robot system has first and second joint control units that respectively calculate first and second current values to be supplied to first and second motors based on deviations between first and second operation targets for the motors that are input from a higher device and actual operation of output shafts of the motor, and control operation of the output shafts by supplying current to the motors based on the current values, and an error estimation unit estimating an error in operation of a second joint due to bending and/or twisting of a robot arm based on the first current value and the actual operation of the output shaft of the first motor, in which the second joint control unit calculates the second current value to control the rotation angle of the output shaft of the second motor in a manner compensating for an angle error of the second joint.

A numerical control device controlling a machine tool capable of machining on orthogonal three axes includes a parameter storage to store a noise-command allowable width to be used for determining whether to perform movement based on a movement command, and a path-correction processor to compare an absolute value of a movement amount according to a movement command in a command non-target axis direction that is a direction of an axis not included in a designated plane with the noise-command allowable width when a machining program block includes the movement command in the command non-target axis direction, determine the movement command in the command non-target axis direction to be a noise command when the absolute value of the movement amount according to the movement command in the command non-target axis direction is smaller, and perform path correction to set a movement amount according to the noise command to zero.

An operation of a processing machine with redundant actuators is controlled according to a reference trajectory by selecting, from a set of points forming a segment of the reference trajectory to be processed for a period of time, a subset of points corresponding to a fraction of the period of time. The subset of points is selected such that the redundant actuators are capable to position the worktool at each point in the subset within the period of time and are capable to maintain the worktool at the last point of the subset after the period of time while satisfying constraints on motion of the redundant actuators. The segment of the reference trajectory is modified in the time domain and the control inputs for controlling the motion of the redundant actuators are determined using the modified segment of the reference trajectory.

A track control apparatus includes an interpolation/acceleration and deceleration calculating unit that interpolates a commanded route and calculates a post-acceleration and deceleration interpolation route, an axis distributing unit that generates a position command for each movable axis from the post-acceleration and deceleration interpolation route, a servo-response calculating unit that calculates a servo response to the position command, a tangential-direction-servo-response calculating unit that obtains a tangential direction servo response from the post-acceleration and deceleration interpolation route, a reference-point generating unit that obtains a reference point from the tangential direction servo response, a position-vector correcting unit that corrects the position command for each movable axis to output a post-correction position command for each movable axis, and a servo control unit that outputs motor driving torque such that each movable axis follows the corresponding post-correction position command.

A robot system has first and second joint control units that respectively calculate first and second current values to be supplied to first and second motors based on deviations between first and second operation targets for the motors that are input from a higher device and actual operation of output shafts of the motor, and control operation of the output shafts by supplying current to the motors based on the current values, and an error estimation unit estimating an error in operation of a second joint due to bending and/or twisting of a robot arm based on the first current value and the actual operation of the output shaft of the first motor, in which the second joint control unit calculates the second current value to control the rotation angle of the output shaft of the second motor in a manner compensating for an angle error of the second joint.

A numerical control device controlling a machine tool capable of machining on orthogonal three axes includes a parameter storage to store a noise-command allowable width to be used for determining whether to perform movement based on a movement command, and a path-correction processor to compare an absolute value of a movement amount according to a movement command in a command non-target axis direction that is a direction of an axis not included in a designated plane with the noise-command allowable width when a machining program block includes the movement command in the command non-target axis direction, determine the movement command in the command non-target axis direction to be a noise command when the absolute value of the movement amount according to the movement command in the command non-target axis direction is smaller, and perform path correction to set a movement amount according to the noise command to zero.

An operation of a processing machine with redundant actuators is controlled according to a reference trajectory by selecting, from a set of points forming a segment of the reference trajectory to be processed for a period of time, a subset of points corresponding to a fraction of the period of time. The subset of points is selected such that the redundant actuators are capable to position the worktool at each point in the subset within the period of time and are capable to maintain the worktool at the last point of the subset after the period of time while satisfying constraints on motion of the redundant actuators. The constraints on motion are selected based on the mode of operation of the processing machine. The segment of the reference trajectory is modified in the time domain and the control inputs for controlling the motion of the redundant actuators are determined using the modified segment of the reference trajectory.

A method computes reference signals for a machine with redundant positioning by first generating a reference trajectory according to an ordered list of points. Then, using a filter or by choosing the value of the reference at each sampling time, a reference trajectory for the slow subsystem is produced. Next, determine whether the reference trajectory and the slow subsystem reference trajectory violate feasibility constraints, and if true, slowing down the reference trajectory and repeating with the generation of the slow subsystem reference trajectory. The slow subsystem reference trajectory is sent, via a model predictive control block, to a slow positioning subsystem controller, and a combination of the slow subsystem reference trajectory and the reference trajectory is sent to a fast positioning subsystem controller.