The positional systems, CNC machining is carried out in process of alternating or simultaneous movement of the working bodies of the machine coordinates for various (X, Y, Z). In the contour control system moves the working parts of the machine along a path (usually curvilinear) and the contour rate specified by the program. Contouring speed is the resultant feed rate of the working bodies of the machine, the direction of which coincides with the tangent at each point in a given circuit processing. In universal systems, CNC use dual-position-contour control system. In open systems, CNC work of the real state of the machine is not monitored, but is determined precision gears and precision to execute a program administered by programmonositelem initial information. In closed systems, there is feedback and by comparing information about controlled execution of movements and commands with the specified parameters in the program.
In closed systems, management identified three subgroups: 1) control system with position feedback of the working machine 2) control system with position feedback actuators and machine tool with compensation of errors due to thermal deformation, tool wear, vibrations, etc., and 3) adaptive (samoprisposoblyayuschiesya, including self-configuring, self-organizing, self-learning) management systems, in which the contingency of technological changes in the system provides high accuracy, the optimum performance and minimal cost of processing through the use of information on various parameters of the process of processing, the size of blanks, loads and temperatures in the cutting area, etc. The name of the system comes from the term ‘adaptation’, meaning the adaptation of organisms to changing external conditions. Work CNC and programming are closely related to coordinate systems. The coordinate axes are needed to determine the movements of the working bodies of the direction and magnitude. For all NC adopted the right system of coordinates X, Y, Z. The coordinate axes are parallel to the guide of the machine. Rotation around the axes X, Y, Z denote letters A, B, C For sharpening of the axial cylindrical blade tool on the front and back surfaces of only two movements, for tools with cylindrical and conical sections of the blade used machines three movements, for a tool with an inclined or helical tooth using machines with four or more movements. When referring to models of CNC machines use indexes: * 2-for positional, FL-contouring, F4-for position-contouring CNC systems, F1-digital position indication with manual data entry. SA Popov.