The present invention suppresses the data size of a data frame to be transmitted to a control device at every control period even if oversampling is performed. A counter unit (10) compresses the data size of sampling data (Sd) indicating a second or subsequent count value (Ct) to the number of bits by which the maximum (Vmax) of a count value countable in one sampling processing can be represented.

An error compensation system for a numerical control (NC) machine tool based on iterative learning control, including a trajectory generating module, a down-sampling module, a position controller, a first holder, a velocity-loop iterative learning controller, a velocity controller, a second holder and a control plant. The trajectory generating module is configured to generate a desired trajectory command including a first sampling command. The first sampling command is transmitted to the down-sampling module and the velocity-loop iterative learning controller. The first sampling command is down-sampled through the down-sampling module to obtain a second sampling command. The velocity-loop iterative learning controller is configured to receive the first sampling command, and obtain a first sampling error compensation sequence according to a first sampling error sequence and a first sampling error compensation sequence of a previous iteration machining process stored therein. An error compensation method is also provided herein.

The present invention suppresses the data size of a data frame to be transmitted to a control device at every control period even if oversampling is performed. A counter unit (10) compresses the data size of sampling data (Sd) indicating a second or subsequent count value (Ct) to the number of bits by which the maximum (Vmax) of a count value countable in one sampling processing can be represented.

A control unit causes a sensor to start sampling at a plurality of start timings different from each other. The control unit combines sampling signals obtained by the start of the sampling at the different start timings, and detects a malfunction of an apparatus in accordance with the combined sampling signal.

A data collection system includes a subordinate controller configured to control an electrical device, and a superordinate controller connected to the subordinate controller via synchronous communication and asynchronous communication to control the subordinate controller. The superordinate controller includes a reference signal transmitter to transmit a timing reference signal to the subordinate controller via the synchronous communication. The subordinate controller includes data storage configured to record data relating to the electrical device; a delay time calculator to measure a delay time from a timing at which the subordinate controller receives the timing reference signal to a timing at which the data storage starts recording the data; and a data transmitter configured to transmit the data and the delay time to the superordinate controller via the asynchronous communication or the synchronous communication.

A control unit causes a sensor to start sampling at a plurality of start timings different from each other. The control unit combines sampling signals obtained by the start of the sampling at the different start timings, and detects a malfunction of an apparatus in accordance with the combined sampling signal.

A data collection system includes a subordinate controller configured to control an electrical device, and a superordinate controller connected to the subordinate controller via synchronous communication and asynchronous communication to control the subordinate controller. The superordinate controller includes a reference signal transmitter to transmit a timing reference signal to the subordinate controller via the synchronous communication. The subordinate controller includes data storage configured to record data relating to the electrical device; a delay time calculator to measure a delay time from a timing at which the subordinate controller receives the timing reference signal to a timing at which the data storage starts recording the data; and a data transmitter configured to transmit the data and the delay time to the superordinate controller via the asynchronous communication or the synchronous communication.

For an improved management of machining information, esp. for a facilitated determination of step features from a sample machining process, a computer-implemented method is suggested comprising: providing a sample machining process for machining a sample workpiece from a sample blank, the sample machining process comprising at least two consecutive sample machining steps performed by the respective tool starting with a respective sample start part and ending with a respective sample end part, wherein the respective sample end part of the respective sample machining step is the respective sample start part of the respective subsequent sample machining step; determining a respective step tool volume corresponding to a movement of the respective tool during the respective sample machining step; determining a respective step volume corresponding to the respective sample start part of the respective sample machining step changed by the respective step tool volume; determining at least one respective step feature corresponding to the respective step volume; and storing the respective step feature in a machining information database.