À propos de cet article


Numerically controlled machines require precise control, because it is always necessary to know the placement of the effector. Control involves the use of electric motors that can be checked with precision. Therefore stepper motors are preferred. A further advance in stepper control is to incorporate a reaction mechanism for the rotor (for example, an encoder) so as communication is optimal for generating the torque, depending on the position of the rotor. This turns the motor into a servo mechanism with very high torque and very good position resolution. An advance in this technique is to operate the motor in a closed loop only if the error of rotor positioning becomes too high. This will allow the system to avoid oscillation while searching for a position, a problem that commonly occurs with servos. The supervision of a numerically controlled tool is limited to the control of electric motors that actuate mechanical assemblies. Control can be implemented by using specialized integrated circuits or microcontrollers. This paper presents a numerically controlled (CNC) machine with microcontroller.