| Five-axis RTCP function can simplify the programming and reduce the nonlinear motion error of the machine tool center point. Different kinds of RTCP algorithms were designed in view of the corresponding topology structures. In that case, the universality and unification of the RTCP algorithm were restricted. The RTCP function achieves the spatial coordinate transformation based on the rotary shaft structure parameters. There were some defects including low efficiency, poor accuracy and application limitation existing in manual measurement method. In this paper, unified RTCP control algorithm and automatic measurement of RTCP parameters were researched based on models of multiple axes rotary spindle head, dual rotary tables and one rotary spindle head with one rotary table.RTCP control models of multiple axes rotary spindle head, dual rotary tables and one rotary spindle head with one rotary table were built to reach the goal of using linear axes motion to compensate the circumgyration of rotary axes through coordinate transform based on the spatial kinematic theory. Software simulation, machine tool test and impeller machining were operated to validate the algorithm. It applied for machine tools less than six axes and those cases of skew and non-orthogonal rotary axes.A method of automatic measurement was proposed in this paper. Based on trigger probe and standard ball, macro program controlled the collision between the trigger probe and the standard ball for the purpose of ball center coordinate acquisition. Least square technique was used to calculate the rotary axes parameters with those standard ball center coordinates. Finally, RTCP parameters were got through this method.A software was developed to actualize the automation of measurement process based on the development platform of HNC-8. Several experiments were operated on three kinds of structures of five-axis machine tool. The experimental result indicated the applicability and high accuracy of this method.In the article, unified RTCP control algorithm was actualized based on three kinds of five-axis machine tools and tested by some experiments, which made up for the disadvantages in unity and universality of the traditional algorithm. Method of automatic measurement was proposed and operated on five-axis machine tools of different structures, which overcame the faultiness of manual measurement. |
