Patent ID: 8060238

Claim:
A computer implemented method of calculating recovery commands for a numerical controlled system, the numerical controlled system comprising an upper controller providing position commands to a servo driver to drive a motor, the method comprising: (a) providing a memory space to store the position commands; (b) reading a position matrix with k-by-1 elements; (c) reading a transformation matrix with k-by-k elements; (d) calculating a plurality of position coefficients of a position polynomial of degree (kâˆ’1); and (e) calculating a plurality of position interpolations according to the position polynomial and the position coefficients, wherein the position polynomial is modified to be a modified position polynomial to synchronize the position commands between the servo driver and a control loop of the upper controller, and the position polynomial is expressed as follows: Î¸(n)=a (k-1) *n (k-1) +a (k-2) *n (k-2) +a (k-3) *n (k-3) + . . . +a 1 *n+a 0 ; and variable n of the position polynomial is replaced by variable t to acquire the modified position polynomial, and the modified position polynomial is expressed as follows: Î¸( t )= a (k-1) *t (k-1) +a (k-2) *t (k-2 +a (k-3) *t (k-3) + . . . +a 1 *t+a 0 wherein t=Ta+nxTs-Tc, and Ta is the time of the position commands are initially transmitted to the control loop; Ts is the time of the position commands are sampled by the control loop; and Tc is the period of the position commands of the upper controller.