Control device and control method for servo motor system

A control method for a control device, the control device generating a command pulse wave group to a servo motor system, the control method comprising steps of:

• (a) controlling the servo motor system in response to a segment stop signal, wherein the segment stop signal represents to stop a first segment and to start a second segment, the command pulse wave group is generated according to the first segment parameter during the first segment, and the command pulse wave group is generated according to the second segment parameter during the second segment;
• (b) receiving a target velocity value, an increment and a predetermined pulse number of the second segment parameter;
• (c) setting a present velocity value as a target velocity value of the first segment parameter;
• (d) judging whether a pulse number of a pulse width modulation signal reaches the predetermined pulse number, wherein if the pulse number of the pulse width modulation signal reaches the predetermined pulse number, the second segment is stopped;
• (e) if the pulse number of the pulse width modulation signal does not reach the predetermined pulse number, judging whether the present velocity value reaches the target velocity value, wherein if the present velocity value reaches the target velocity value, the step (d) is repeatedly performed;
• and
• (f) if the present velocity value does not reach the target velocity value, updating the present velocity value to a sum of the present velocity value and a modified increment, and repeatedly performing the step (d), wherein the modified increment is equal to a product of the increment and a weighting value,
• wherein the control device generates the pulse width modulation signal and determines a frequency of the pulse width modulation signal according to the present velocity value, wherein the pulse width modulation signal is used as a first signal of the command pulse wave group.