A method for predicting and compensating frictions of a feed system includes following steps: constantly obtaining current signals and angle-position signals of a motor by a motor driver of a feed system after being activated; calculating frictions of the motor upon each rotating position according to the obtained current signals and angle-position signals and generating multiple records of friction data; creating a friction model according to the multiple records of friction data and the angle-position signals each respectively corresponding to each record of friction data with respect to each rotating position; importing current angle-position signal of the motor to the friction model for predicting a predicted friction; calculating a compensation current based on the predicted friction; and, controlling the motor driver to additionally provide the compensation current to the motor for conquering an upcoming friction of the feed system approximate to the predicted friction.

A method of controlling an electrical actuator of a mechanical system having a plurality of nested zones of contact, the method comprising the steps of: acquiring data about the mechanical system, which system includes a number of nested zones of contact; preparing a model of the system on the basis of said data and of a number of LuGre models put in parallel equal to the number of nested zones of contact, and determining parameters of the model and also a compensation structure for compensating friction in the nested zones of contact; including the compensation structure in a control relationship for the actuator A; and controlling the actuator by means of the control relationship.

A computer-implemented method for reducing friction within a machine tool is provided, including: a) reading a plurality of surrogate models for approximating friction compensation within a given machine tool, b) reading a friction compensation parameter set, c) determining a friction compensation result value for each surrogate model using the compensation parameter set, d) determining a weighted average friction compensation value of the friction compensation result values using the respective weighting factor, e) deducing a quality indicator for the friction compensation parameter set based on the weighted average friction compensation value, f) outputting the friction compensation parameter set, if the quality indicator fulfils a given quality criterion, or repeating b) to e) until the quality indicator fulfills the given quality criterion, g) applying the outputted friction compensation parameter set to the machine tool for reducing friction within the machine tool.

A dry friction compensation method for at least one mass or inertia M mobile under the effect of at least one effector element controlled by a force or torque control signal U, the motion of the mass or inertia being characterized by a motion signal Y chosen among one or several of the position X, the speed V and the acceleration, the method includes: defining an ideal model of the closed loop; defining a dry friction compensation control law; the dry friction compensation control law being based on the following friction model:

[00001]$P=\min \left(\max \left(\frac{\mathrm{VM}}{\tau }+U,-S\right),S\right),$ where V is the speed of the mobile mass or inertial subjected to the friction and τ a minor time constant, and S is a parameter of dry friction.

A method for predicting and compensating frictions of a feed system includes following steps: constantly obtaining current signals and angle-position signals of a motor by a motor driver of a feed system after being activated; calculating frictions of the motor upon each rotating position according to the obtained current signals and angle-position signals and generating multiple records of friction data; creating a friction model according to the multiple records of friction data and the angle-position signals each respectively corresponding to each record of friction data with respect to each rotating position; importing current angle-position signal of the motor to the friction model for predicting a predicted friction; calculating a compensation current based on the predicted friction; and, controlling the motor driver to additionally provide the compensation current to the motor for conquering an upcoming friction of the feed system approximate to the predicted friction.

A control device, a control program and a control system are provided. The control device includes: a first identification device for giving a first command as a command value to a drive device and determining a torque required for the controlled object to execute the first command; a second identification device for giving a second command as the command value and a third command as a compensation command to the drive device and determining a preceding switching time based on a response from the controlled object; a command value updating device for sequentially updating the command value based on a predetermined target trajectory; and a compensation command updating device for sequentially updating the compensation command based on the command value. The compensation command updating device updates the compensation command according to a moving direction after a reversal of the moving direction of the controlled object in the target trajectory.

A dry friction compensation method for at least one mass or inertia M mobile under the effect of at least one effector element controlled by a force or torque control signal U, the motion of the mass or inertia being characterized by a motion signal Y chosen among one or several of the position X, the speed V and the acceleration, the method includes: defining an ideal model of the closed loop; defining a dry friction compensation control law; the dry friction compensation control law being based on the following friction model: $P=\min \left(\max \left(\frac{\mathrm{VM}}{}+U,-S\right),S\right),$ where V is the speed of the mobile mass or inertial subjected to the friction and a minor time constant, and S is a parameter of dry friction.

A controller that performs, for one or more axes of a machine, position control by taking friction into consideration includes a data acquisition unit acquiring at least a position command and a position feedback and a compensation torque estimation unit estimating coefficients of a friction model used when the position control is performed, on the basis of a position deviation which is a difference between the position command and the position feedback.

The invention provides a control device comprising: an actual value obtaining part, obtaining a torque actual value and a velocity actual value, wherein the torque actual value represents a torque generated by the driving source and the velocity actual value represents a velocity of the motion body; an inferring part, which calculates an external force inferred value and a velocity inferred value every other operation period based on the torque actual value by using an operation formula of a predetermined model representing driving of the motion body, wherein the external force inferring value represents an external force generated by the control system; and an output part, evaluating a reliability of the external force inferred value based on the velocity inferred value calculated together if the inferring part calculates the external inferred value, and effectively outputting the external force inferred value when it is judged that there is a designated reliability.

A gripper which has a friction estimation module configured to estimate static and/or dynamic friction forces acting on gripping jaws is provided. The static friction force is calculated on the basis of constraining reactions whereto the gripping jaws are subjected, the constraining reactions being calculated at least as a function of an actuation force exerted on the gripping jaws, a coefficient of friction of gripper materials and/or lubricant used being known. The dynamic friction force is calculated on the basis of speed of the gripping jaws, width of sliding surfaces and distance between the sliding surfaces of the gripping jaws, the viscosity of the lubricant used being known.