| 摘要 |
A computer numerical control CNC machine tool 5 has a machine head 6 with a tool(s) e.g. a drill spindle (18, fig 5). The machine head is moveable with respect to a workpiece e.g. rib feet (2a, fig 4) of an aircraft wing box jig (1, fig 1). A position sensor system having an ultrasonic probe (17, fig 4) detects the position of the machine head 6 relative to the workpiece. A controller coupled to the position sensor system provides closed loop control of the position of the machine head 6 relative to the workpiece. |
