Electrical tracer control system utilizing sine wave resolution
OwnerRobert H. Wenzelinventor
Life of this patent
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Abstract
A control for a profiling machining tool, and a method for controlling such a tool. The machine tool includes a sensing head which moves along a template or pattern to produce a signal that causes motors relatively to shift a cutting tool and a workpiece so as to duplicate in the workpiece the profile of the template or pattern. Two sinusoidal signals are generated as a consequence of stylus deflection along orthogonal axes. They are combined to form a single sinusoidal signal which is then variously processed to produce an error signal which causes the motors to operate in directions which tend to reduce the error signal, and to cause the stylus automatically to move along the profile while doing so.
Claims18
A control for a profiling machine tool of the type which includes means mounting a cutting tool, and is adapted to cause relative motion between said cutting tool and a workpiece along at least two orthogonally-related axes so the said cutting tool can traverse a path relative to the workpiece which is geometrically similar to the contour of a template or pattern, motor means respective to each of said axes for causing relative motion along each respective axis, a sensing head of the type having a deflectible stylus and, coupled to said stylus, a pair of stylus position transducers each respective to one of said axes and adapted to produce a signal with a magnitude indicative of stylus defection in the respective axis, said control comprising:
- a source of excitation voltage to excite each of said transducers with a sinusoidal voltage to produce a signal from both of said transducers, the excitation voltages applied to said transducers being 90.degree. out of phase with one another;
- means combining said signals from said transducers to provide a single sinusoidal transducer output signal;
- voltage regulator means receiving said single signal and producing a regulated signal whose time of zero voltage crossing is in time phase with the same zero crossing of said single signal and having a constant and pre-determined sinusoidal voltage;
- adjustable stylus deflection control means providing a direct current command signal proportional to a desired stylus deflection;
- multiplier means multiplying one of said regulated signal and said single signal by said direct current command signal to produce a multiplied signal;
- inverting means inverting one of said single signal, regulated signal or multiplied signal;
- means receiving and combining said multiplied signal, and whichever of said regulated signal and single signal that was not multiplied by said direct current command to produce a sinusoidal error signal;
- and
- resolution means receiving said error signal and producing motor control signals respective to stylus error on respective axes, which enable power to be supplied to drive respective motors in such directions as to reduce the error signal as the consequence of changing the relative position of the sensing head and template or pattern by operation of said motors.
Dependencies are inferred from the claim text.