Servo control device and method of adjusting servo system

A method of adjusting a servo system comprising:

• a step of instructing a position instruction having periodicity;
• a step of drawing position data based on a position feedback of a servo system according to the position instruction, data before a quarter cycle or after a quarter cycle of the position data or position data based on the position instruction before a quarter cycle or after a quarter cycle, on a two-dimensional plane including two orthogonal axes, as the axis data of the orthogonal two axes respectively;
• a step of drawing, in superimposition on the two-dimensional plane, the position data based on the position instruction and data before a quarter cycle or after a quarter cycle of the position data, as axis data of the orthogonal two axes respectively;
• and
• a step of adjusting the servo system so that a shape drawn based on the position data based on the position feedback and the data before a quarter cycle or after a quarter cycle of the position data or the position data based on the position instruction before a quarter cycle or after a quarter cycle, becomes closer to a shape of an evaluation reference, using a shape drawn based on the position data based on the position instruction and the data before a quarter cycle or after a quarter cycle of the position data as the evaluation reference.