OBRABOTKAMETALLOV MATERIAL SCIENCE Том 23 № 3 2021 EQUIPMEN . INSTRUM TS Vol. 6 No. 1 2024 One of the investigation targets is to time the machine drives and circuit current polarity reversing. Current polarity may be reversed either in sequence during operation at set time intervals (for electrochemical grinding and dressing) or when changing the material to be machined from one to another (soldered joints, sandwich materials). According to the investigation procedure, an experiment should be performed, during which the machine’s CNC system shall be timed with the current polarity switching control system. For the purpose of the results estimation, we compared the time for the diamond wheel movement during the working stroke with the pulse duration of various current polarities set by the process sequence of developed SW. Results and its discussion During the investigation, we developed the shared control logic for the machine’s step motors and current polarity reversing relay block shown in fi g. 5. Fig. 5. Joint control circuit of machine stepper motors and relay unit To time the machine’s driven element step motors control with the relay block operation, we developed special SW for automatic control of step motors and relay block shared operation. Special software interface is shown in fi g. 6. In the SW interface, there are fi elds to display axis motion coordinates, area for axis movement manual control, window to display the set process sequence and enter the required values as well as virtual bar to select the program codes. Besides, using the interface, one can specify the PC COM port to be used, manipulate, safe and open process sequence fi les, start/stop/terminate program execution, monitor line current polarity and voltage, retrieve error messages, delete fi les. Apart from the underlying codes, such as G00 – fast positioning. G01 – linear interpolation. М3 – spindle rotation activation and М5 – spindle rotation deactivation, special codes were developed and introduced. For example, М7 – current polarity reversing activation/deactivation commands, М8 – direct current polarity activation, М10 – reverse current polarity activation, and М11 – switch to interactive control of current polarity. Duration of the set polarity current pulse is set in an interactive way from the indication unit using the data display panel, shown in fi g. 7. In fi g. 8 an analytic model to test the developed process sequence is presented for shared operation of the machine’s CNC system and the current polarity switching control system when changing the material to be machined from material 1 to material 2, namely, for the grinding wheel movement along the Z axis. In fi g. 9 readings of the indication unit display, used for interactive operation, obtained during the experiment are presented.
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