Abstract: Methods and apparatus disclosed herein implement or otherwise embody a technique that compensates for cyclic position errors in encoder-based position detection, wherein the cyclic position errors arise from the presence of harmonic components in the encoder signals relied upon for position determination. Using position-domain compensation for errors arising in the encoder domain offers computational simplicity and impressive compensation performance, even when compensating for a plurality of higher harmonics in the encoder signals, e.g., third harmonic, fifth harmonic, etc. Consequently, even high-precision position monitoring or control can use relatively inexpensive types of encoders known to output encoder signals having significant harmonic components.
Abstract: Presently disclosed is a method and system for processing standard part description programs in real time into the tool position control data appropriate to a CNC machine's standard and high bandwidth mechanisms, respectively. The result is precise tool tip control that tracks the programmed path at all times while maintaining the appropriate feed rates and accelerations for each type of mechanism. In one exemplary embodiment, a hybrid mechanism employing a high bandwidth mechanism mounted on and moved by a standard mechanism is employed. The command vector for the high-bandwidth mechanism is computed by subtracting the tool tip vector filtered to comprise only the tool tip positions and trajectories realizable by the standard mechanism from an ideal tool tip trajectory vector that represents the complete programmed path. These calculations produce a synchronous set of movements for both standard and high bandwidth mechanisms.
Abstract: Presently disclosed is a method and system for processing standard part description programs in real time into the tool position control data appropriate to a CNC machine's standard and high bandwidth mechanisms, respectively. The result is precise tool tip control that tracks the programmed path at all times while maintaining the appropriate feed rates and accelerations for each type of mechanism. In one exemplary embodiment, a hybrid mechanism employing a high bandwidth mechanism mounted on and moved by a standard mechanism is employed. The command vector for the high-bandwidth mechanism is computed by subtracting the tool tip vector filtered to comprise only the tool tip positions and trajectories realizable by the standard mechanism from an ideal tool tip trajectory vector that represents the complete programmed path. These calculations produce a synchronous set of movements for both standard and high bandwidth mechanisms.
Abstract: A system and method for generating a controlled motion path with a machine-tool system having a controller operating in a servo rate. The method includes a first interpolation step, in which a path segment corresponding to a number of servo update periods is calculated. After the first interpolation step, a speed override factor is established. After establishing the speed override factor a second interpolation step occurs, which includes calculating a number of path setpoints for each path segment. The number of servo update periods per path segment may vary over the path.