Prediction Modeling and Sensitivity Analysis of Robot Bone Milling Temperature Operated by a Doctor

Table 5

Range of test factors and coding table of quadratic regression design.

Range of variable x	Actual variable x			Standardization of z
Variable	x1	x2	x3	z1	z2	z3
Above level	x12	x22	x32	1	1	1
Zero level	x10	x20	x30	0	0
Under level	x11	x21	x31	−1	−1
Distance from r horizontal				r	r	r
Distance from −r horizontal				−r	−r	−r
Standard deviation