Profiling control apparatus and control method thereof

摘要

An improved profiling control apparatus controls a profiling machine so that the apparatus judges whether an exact profiling operation is performed by the machine at a place where a surface shape of the model to be profiled is suddenly changed, for example at a step, without jumping of a stylus from the model surface, and the profiling machine performs the exact profiling operation without jumping of the stylus. The profiling control apparatus, which detects a displacement of the stylus pressed on the model surface from a tracer head and controls the profiling machine in accordance with the displacement detection signal, includes a displacement compounding unit for compounding three dimensional displacement signal epsilon x, epsilon y and epsilon z to produce a displacement signal epsilon (= 2ROOT epsilon x2+ epsilon y2+ epsilon z2), a displacement differentiating unit for differentiating the displacement signal to produce a differentiated value d2 epsilon /dt2, a comparison voltage producing unit for producing a comparison voltage Vc corresponding to a maximum acceleration beta max of the pressed stylus which can be produced thereon, and a comparison unit for comparing the comparison voltage Vc with the differentiated value d2 epsilon /dt2 to produce a jumping detection signal when d2 epsilon /dt2=Vc. The profiling control unit is particularly suitable for profiling the model surface of which a shape is suddenly changed.