Minimum Time Trajectory Optimization of CNC Machining with Tracking Error Constraints

Table 1

Performance comparison among MTT, SMTT, TEC-SMMT, and RTEC-SMTT for the ellipse path.

	Planning time*	Machining time (s)	Mean tracking error (μm)		Maximum tracking error (μm)
			𝑋-axis	𝑌-axis	𝑋-axis	𝑌-axis
MTT	5.84 s	1.527	52.97	20.06	104.21	55.06
SMTT	8.69 s	1.900	39.19	16.04	102.18	49.91
TEC-SMTT	23.15 s	2.160	31.52	12.22	50.06	39.23
RTEC-SMTT	15 min^♢	2.077	33.95	12.82	52.31	39.58

∗Planning times in this table are obtained under the conditions of initial guess 0.001 and number of parameterized grids 200.
^♢Since the RTEC-SMTT is hardly to be obtained, the planning time for this trajectory is only an estimate by repeated attempts.