Abstract: Methods and apparatus for performing error compensation by modifying encoder-type position feedback signals supplied to a machine tool controller is illustrated by four embodiments. The first embodiment inserts compensation pulses into position feedback signals by using OR gates, when both square waves of the feedback signals are logically low. The addition or subtraction of the compensation pulses is performed by inserting the compensation pulses at a particular phase relative to each other. The second embodiment is capable of inserting correction pulses when the square waves are in any logical state. The third embodiment is capable of correcting the error completely controlling the feedback signals and not using OR gates to insert correction pulses, but requires a faster microcomputer. The fourth embodiment uses inverters incorporated sequentially, instead of OR gates, to invert the square wave signals before they are supplied to the machine tool controller.

Abstract: A system is provided for predicting when the failure of a rotating machine ool or part is imminent or when a tool is worn. The system includes a transducer for producing an output related to the workpiece vibrations caused by the machine tool and an analog comparator which compares this output with a threshold signal related to the normal operation of the tool and established by a microcomputer which determines whether further signals which exceed the threshold are produced during each of a predetermined number of subsequent time intervals related to the rotational speed of the tool. If so, a "failure" signal is produced which may be used, for example, to cause retraction of the tool.

Abstract: A wide dynamic range, wide bandwidth, analog-to-digital conversion system d method. A plurality of overlapped analog-to-digital converters are utilized in conjunction with scaling amplifiers to provide a plurality of output ranges. Means for selecting the set of output bits which provides a magnitude representation of the input signal are provided along with means for outputting a digital representation of the appropriate range.

Abstract: A wide dynamic range, wide bandwidth, analog-to-digital conversion system and method. A plurality of overlapped analog-to-digital converters are utilized in conjunction with scaling amplifiers to provide a plurality of output ranges. Means for selecting the set of output bits which provides a magnitude representation of the input signal are provided along with means for outputting a digital representation of the appropriate range.