METHOD FOR GENERATING AXIS CONTROL DATA FOR USE IN CONTROLLING A GRINDING MACHINE AND THE LIKE AND SYSTEM THEREFOR

A method and apparatus are provided for controlling a cam grinding machine and the like by kinematically modeling (FIGURES 10 through 21) the cam generating geometry of the grinding machine and using the kinematic model to convert cam lift data (FIGURES 3A and 3B), which is related to the desired contour of a cam (12 or 14), to a form which is usable by first and second drive axis controllers (80 and 76). The cam lift data is analyzed (110) through the use of a fast fourier transform (FFT) (116) to thereby obtain FFT coefficients (118) which define the amplitude and frequency content of the cam lift data. Through a combination of the kinematic model and an inverse FFT procedure, an axis control function including a position control function (Eq. 1 and Eq. 14) is determined (128) for each axis. Dynamic compensation (130) of each axis is provided for system lags and inertia loads by altering the axis control function as a proportion of the axis velocity and acceleration (130), respectively. For each controlled axis an independent vector and a corresponding dependent vector containing axis control data is generated (132). During the actual control of first and second drive motors (72, 70) of the grinding machine, position and velocity feedback signals are generated for each axis by feedback devices (82, 78). A master/slave control arrangement is provided between the two axes wherein the positional feedback signal (86) from one axis is utilized in the control of the other axis to eliminate time lags between control of the two axes.