Siemens Energy & Automation, Inc.

Siemens Aktiengesellschaft

Siemens Industry, Inc.

Vickers, Inc.

Trinova Limited

Stephen J Yutkowitz

Elmar Schäfers

Steffen Udluft

Torsten Schür

Daniel Hein

R William Kneifel, Ii

Stephen T Walsh

Philipp Rost

Peter Schiffer

Alexander Kubik

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.

Reduction of friction within a machine tool

An actuator of a machine is controlled by a control device with a controller structure in a normal operating mode and a special operating mode. The control device determines from a position setpoint value and a position actual value a control signal for the actuator. In the normal operating mode, the setpoint values are determined using a utility program, and in the special operating mode by a system program that is different from the normal operating program. In the special operating mode, a frequency characteristic for the actuator is determined on the basis of the sequence of setpoint values and associated actual values, and an evaluation for the actuator and/or of the controller structure is performed using the frequency characteristic and parameters of the controller structure. Depending on the evaluation, a message is transmitted to an operator of the machine or to a computing device over a network.

Automatic evaluation of a machine behaviour

A system, method, and device for generating a signal processing network for deployment on a motion control system are disclosed. The exemplary system may have a module that supplies one or more signal processing units represented in data format using existing compiled and linked code. Another module provides a dedicated interface with the motion control system. The system may also have a module that supplies each signal processing unit with multiple inputs and multiple outputs and a module that routes the inputs and the outputs between the one or more signal processing units.

Signal processing network

The present invention is a novel device, system, and method for simultaneous selection of filters and loop proportional gain for a closed loop system. According to an exemplary embodiment of the present invention, a method provides an automated selection of the portion of the controller known as the speed loop compensator. The method may operate on a frequency response function that represents the dynamic response from an actuation force (e.g. motor torque) to the sensor used for feedback of speed control (e.g. motor encoder angle). The frequency response function may be represented as a series of complex numbers each with a corresponding frequency value. The tuning method determines the combination of filter parameters that allows the loop proportional loop gain (K) to be maximized while meeting a specified set of criteria for stability margins. Methods for selecting integral gain and reference model are also presented.

Automating tuning of a closed loop controller

The present invention is a novel device, system, and method for determining the damped natural frequencies of a dynamic system whose characteristics are available in the form of a 'frequency response function' FRF. According to an exemplary embodiment of the present invention, the method identifies the dampened natural frequencies associated with the poles and zeros of a transfer function. The method is especially useful for analysis of measurements that contain some degree of contamination due to noise or non-linear effects. It is based on a set of rules that may be more successful than a direct approach based on a least squares criteria.

Method for determining the damped natural frequencies of a dynamic system

A method and apparatus for tuning a feedforward compensation parameter in a motion control system is provided. According to one such embodiment, the method includes the acts of determining an initial value of a feedforward compensation parameter and commanding an initial movement of an actuator according to a test motion routine (wherein the initial value of the parameter is used in the control of the actuator). Error associated with the initial movement is determined. A potential value of the feedforward compensation parameter is determined. A movement of the actuator is commanded according to the test motion routine (wherein the potential value of the parameter is used in the control of the actuator) and error associated with the movement is determined. The errors associated with the movements are compared and, based on the act of comparing the errors, one of the values is selected as a current best value. In a further embodiment, such acts are repeated until the current best value is an optimum value.

Method and apparatus for tuning compensation parameters

A method and apparatus for controlling motion through consecutive linear spans that define a corner in a desired motion path, such as a motion path in a machine tool system for example, is disclosed. In one embodiment, a plurality of data points that define a desired motion path is provided, and the plurality of data points define a plurality of consecutive spans. It is determined whether two consecutive linear spans define a corner having an angle within a predetermined range, and if so, a non-linear path is determined which connects to the two consecutive linear spans with continuity in curvature. An actuator is then controlled according to the non-linear path.

Apparatus and method for smooth cornering in a motion control system

In one embodiment, a method and machine are provided for tuning compensation parameters in a motion control system associated with a mechanical member. The method includes the steps of receiving an indication of a compensation parameter to be tested, based on the compensation parameter to be tested causing a signal associated with a desired motion of the mechanical member to be commanded, acquiring control data associated with the signal, acquiring measurement data associated with actual motion of the mechanical member in response to the signal, analyzing the control and measurement data; and based on the step of analyzing the control and measurement data, implementing a value of the compensation parameter.

Method and apparatus for tuning compensation parameters in a motion control system associated with a mechanical member

In one embodiment, a method of and apparatus for self-calibrating a motion control system is provided. The method includes the steps of receiving a test parameter, ensuring a reasonable test can be executed based on the test parameter, generating a part program based upon the test parameter, instructing a user of the motion control system regarding set up of a device capable of acquiring data associated with the test, and executing the test, wherein the part program is executed as part of the test.

Method and apparatus for self-calibrating a motion control system

In one embodiment, a method of and apparatus for determining calibration options in a motion control system is provided. The method includes the steps of measuring error in a commanded motion, modeling the error, identifying sources of the error; and predicting a degree to which applying compensation for one of the sources of the error might affect the error.

Method and apparatus for determining calibration options in a motion control system

A spline interpolation motion control system and method that can automatically determine where sharp corners and flat sections were intended in a part program. In one embodiment, based upon the length ratio of two consecutive spans, the system and method determines whether to interpolate the first span with a line or with a spline function. If a parameter range is not met, then the span is interpolated as a line to maintain the intended flat section in the program. Also, in this embodiment, the angle defined by a pair of consecutive spans is used to determine whether the two spans should be interpolated with lines or with splines. If a tolerance is exceeded, then the spans are interpolated linearly to maintain the intended sharp corner in the part program.

Motion control system and method utilizing spline interpolation

A method and apparatus for automatically tuning feedforward parameters is provided, such that feedforward commands can be generated and used in addition to traditional control commands to compensate for known system characteristics. In an exemplary embodiment, feedforward gains are automatically determined after moving an actuator controlled axis, such as a motor imparting motion to a linear slide, through a test motion routine and recording operation data associated with the actuator and axis during the movement. The operation data can include velocity measurements and torque commands. The feedforward gains which are tuned can include a Coulomb friction feedforward gain, a viscous friction feedforward gain, a constant offset feedforward gain, an acceleration feedforward gain, and estimates of velocity loop compensator gains. Capability can also be provided for automatic generation of the test motion routine based upon actuator limit values provided by the user.

Method and apparatus for automatically tuning feedforward parameters

A method and apparatus for tuning control loop parameters in a motion control system, is provided. In one embodiment, tuning of the proportional and integral gains of a servocontroller's velocity loop compensator is provided, as well as tuning of the cutoff frequencies of the servocontroller's low pass filters. In this embodiment, random noise excitation is added to the velocity command during a plurality of movement types for a machine tool axis. During each movement type, frequency response measurements are taken. Then, a composite frequency response can be selected by concatenating portions of the various frequency response measurements, so as to simulate a worst case scenario for the machine tool axis. From this composite response, an open loop response can be calculated and displayed, as well as bandwidth, phase margin, and gain margin values. The user can then enter the compensator parameters which were used when this data was taken, as well as proposed parameters. The system can automatically predict, or simulate, the effects of the proposed parameters on bandwidth, gain margin, and phase margin, based upon the composite data. Accordingly, the user need not actually try out the proposed parameters on the machine. Moreover, the simulated responses for the proposed parameters are based upon actual frequency response data taken during actual operating conditions of the system, and, accordingly, the inaccuracies of using mathematical assumptions are avoided.

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Cincinnati, OH, United States of America

Stephen J Yutkowitz