Low speed control method and apparatus for servo motor

A low speed control apparatus for a servo motor, the low speed control apparatus comprising:

• the servo motor;
• an encoder, acquiring a speed signal from a servo motor and encoding the speed signal to output a low-resolution encoded signal;
• an insertion calculation unit, receiving the low-resolution encoded signal from the encoder to be processed by an interpolation operation for converting the low-resolution encoded signal into a high-resolution encoded signal to be outputted therefrom;
• a servo control chip, setting internal parameters and receiving the high-resolution encoded signal from the insertion calculation unit to be processed by a calculation process so as to output a switch control instruction;
• and
• a power module, receiving the switch control instruction from the servo control chip and then transmitting the same to the servo motor for adjusting the operation speed of the servo motor,
• wherein a numerical analysis in interpolation by the insertion calculation unit is to increase the number of square waves of a signal inputted by the encoder and transmit the signal to the servo control chip and the resolution is enhanced by setting internal parameters in the servo control chip;
• and
• wherein the interpolation algorithm is to calculate the number of square waves for each interpolation operation according to final resolution parameters in the servo control chip and current resolution parameters in the encoder, and to output the square waves after output frequency is calculated according to current servo motor speed and the speed command.