(1) The main structure of the three-dimensional laser cutting machine. The three-dimensional laser cutting machine adopts the design of flying light path, that is, the workpiece does not move during the processing process and is completed by the movement of the laser head. The sensor structure adopts a non-contact capacitive sensor, and the laser head and parts are used as two poles respectively. The laser head is three-dimensional and five-axis linkage, that is, the three basic coordinate axes of X, Y, and Z, the two rotation axes of A and B, and the C axis for adjusting the focus. It can be seen from the figure that it is different from the two-dimensional laser cutting machine. The three-dimensional laser cutting has two more rotating shafts. Among them, the A-axis can rotate 360°, and the B-axis can swing within the range of u0026plusmn;135u0026deg;. In addition, a hand-held box for 3D programming is also provided. (2) The movement mode of the machine tool during three-dimensional cutting There are three main movement modes of the machine tool: ABS, ROB, and TCP. Among them, ABS is usually not used, ROB is mainly used in two-dimensional plane cutting, and TCP (Tip Center Point) is used in three-dimensional cutting. During TCP movement, the movement of the laser head does not follow the ordinary movement mode, but the coordinate system of the laser head part has changed, forming a new mechanical reference coordinate system, the machine tool coordinate system is Xm, Ym, Zm, Tcp is the point where the center of the current nozzle is located. At this time, the Z direction of the reference coordinate system is not consistent with the machine tool Zm. Instead, the reference coordinate system has been transformed to a certain extent. The reference system is based on the opposite direction of the optical path as the Z direction. The direction of Y also changes, that is, the directions of Xtcp, Ytcp, and Ztcp in the figure. At this time, when moving X, Y, and Z, the machine tool will move along the new mechanical reference coordinate system instead of the machine coordinate system. Another special point is that when the A-axis or B-axis is rotated, the coordinates of the nozzle center point Tcp in the machine tool coordinate system remain unchanged, that is, the nozzle center does not move, and the laser head moves around the nozzle center. The nozzle center can only be moved when Xtcp, Ytcp or Ztcp is moved. Setting the TCP motion mode is mainly to facilitate the operation of the target point on the space curve. The specific function will be explained in the following instruction introduction and actual processing. (3) The function of automatically aligning the normal line of three-dimensional cutting. Three-dimensional laser cutting also has the function of automatically aligning the normal line of the curve, which is the AUTOSQUARE command. When the target point is found, execute AUTOSQUARE, the sensor will automatically find several points around the target point to determine the space surface shape around the current point, and calculate the direction coordinates of the point (A, B axis coordinates), and automatically Adjust the laser head to the normal direction. Since the TCP motion mode is adopted, and only the direction coordinates are adjusted, the position coordinates of the nozzle center will not change when the laser head direction is adjusted. According to the introduced sensor structure, three-dimensional motion mode and automatic normal line function, the first two technical difficulties can be easily solved. Automatically align the normal to ensure that the laser beam and the curve remain vertical, and use the sensor to keep the distance between the center of the nozzle and the surface of the part consistent.