Abstract: A simulation system (20) for a CNC machine tool includes a swept surface calculation engine (21) for processing workpiece data and grinding wheel data representing information about the grinding wheel (12) and its programmed path to generate a set of geometric envelopes representing the solid volume occupied by the grinding wheel (12) as it moves along its programmed path. The envelopes, workpiece data and grinding wheel data are processed by a 3-D rendering engine (22) to produce a three-dimensional perspective image of the workpiece (11) as it would appear after being ground by the grinding wheel (12). The simulation system (20) also includes a manipulation and control interface 923) which may be used for a wide variety of purposes to enhance the three-dimensional image, such as position, orientation and zoom control, control of simulated illuminated light sources, control of texture maps and color maps and overlay grids which may be superimposed on the surface of the simulated workpiece image.

Abstract: A multi-axis computer numerically controlled machine tool is provided in which a cutting tool is movable relative to a workpiece by a number of linear and rotary joints under the control of a programmable control unit. The machine is programmed with a plurality of principal programmable axes, called "hard" axes, and with at least one synthesised additional programmable axis or "soft" axis which enables the cutting tool to be moved linearly in the direction of the soft axis without requiring a specific joint for that purpose. The synthesised "soft" axis is a non-collinear, partially redundant axis which increases the number of programmable degrees of freedom to a greater number than the machine degrees of freedom, i.e., the number of non-collinear joints. The principle of synthesising "soft" axes may be extended to CNC machine tools having four or more principal hard axes, for instance, to produce a 5-joint CNC machine tool which has the flexibility of a conventional 7- or 8-joint machine tool.

Abstract: A multi-axis computer numerically controlled (CNC) machine tool is provided in which a cutting tool (7) is movable relative to a workpiece (6) by means of a number of linear and rotary joints (J.sup.1 to J.sup.3) under the control of a programmable control unit (1). The machine is programmed with a plurality of principal programmable axes, called "hard" axes (X, Z and B), and with at least one synthesized additional programmable axis or "soft" axis (V) which enables the cutting tool (7) to be moved linearly in the direction of the soft axis (V) without requiring a specific joint for that purpose. The synthesized "soft" axis is a non-collinear, partially redundant axis which increases the number of programmable degrees of freedom to a greater number than the machine degrees of freedom ie: the number of non-collinear joints.