Encoder Accuracy Compensation Method
Original Publication Date: 1989-Mar-01
Included in the Prior Art Database: 2005-Jan-27
This is an accuracy compensation method for rotary or linear position encoders which have following characteristics on the output signals. A = a * sin(g * P - Pd) Eq. 1 B = b * cos(g * P) Eq. 2 A and B are the encoder outputs which are determined as voltage signals corresponding to position P. The parameters a and b indicate each voltage gain. Pd is the angle error between sin and cos phases, and g is the angle gain parameter of the encoder. In the case of rotary encoder, g corresponds to sin or cos pulse number per revolution. Here, a / b = c c,g,Pd : Fixed parameter on each encoder Case 1 Obtaining Position Signal as a combination of A,B,-A,and -B, as in the figure, the position P is determined as Eqs. 3 and 4. P = Pn + Po Eq.