Tracing feed rate control circuit

Claim 2

An automatic tracing apparatus comprised in part of a tracing head including a tracing finger for tracking a three-dimensional model and a tracing control producing therein an error signal representing an erroneous deflection within a tracing plane in a direction perpendicular to a model surface at a tracing poInt, and a feed rate command signal having a magnitude representing a predetermined tracing velocity within the tracing plane tangent to the model surface at the tracing point, wherein the improvement comprises: a. means responsive to the error signal for producing a control signal as a function of an overdeflection of the tracing finger being caused by said tracing finger encountering a change in direction of an internal contour of the model, said control signal representing a deceleration characteristic; and b. means responsive to the control signal and the feed rate command signal for modifying the feed rate command signal as a function of the deceleration characteristic of the control signal whereby the magnitude of said feed rate command signal decreases and subsequently increases gradually to its original magnitude.

Claim 3

An automatic tracing apparatus comprised in part of a tracing head including a tracing finger for tracking a three-dimensional model and a tracing control producing therein an error signal representing an erroneous deflection in a tracing plane in a direction perpendicular to a model surface at a tracing point and a feed rate command signal having a magnitude representing a predetermined tracing velocity in the tracing plane tangent to the model surface at the tracing point, wherein the improvement comprises: a. means responsive to the error signal for producing a first signal in response to an overdeflection of the tracing finger defining a rapid non-cyclic increase in the error signal; b. means responsive to the first signal for producing a control signal as a function of the second derivative of the rapid non-cyclic increase in the error signal; and c. means responsive to the control signal and the feed rate command signal for modifying the feed rate command signal whereby the magnitude of said feed rate command signal decreases and subsequently increases as a function of the second derivative of the rapid non-cyclic increase in the error signal.

Claim 4

An automatic tracing apparatus comprised in part of a tracing head including a tracing finger for tracking a three-dimensional model and a tracing control producing therein an error signal representing an erroneous deflection in a tracing plane in a direction perpendicular to a model surface at a tracing point and a feed rate command signal having a magnitude representing a predetermined tracing velocity in the tracing plane tangent to the model surface at the tracing point, wherein the improvement comprises: a. means responsive to the error signal for producing a first signal in response to an overdeflection of the tracing finger defining a rapid non-cyclic increase in the error signal; b. means responsive to the first signal for producing a control signal as a function of the second derivative of the rapid non-cyclic increase in the error signal; and c. means responsive to the control signal and the feed rate command signal for modifying the feed rate command signal whereby the magnitude of said feed rate command signal decreases and subsequently increases as a function of the second derivative of the rapid non-cyclic increase in the error signal.

Claim 5

An automatic tracing apparatus comprised in part of a tracing head including a tracing finger for tracking a three-dimensional model and a tracing control producing therein an error signal representing an erroneous deflection in a tracing plane in a direction perpendicular to a model surface at a tracing point and a feed rate command signal having a magnitude representing a predetermined tracing velocity in the tracing plane tangent to the model surface at the tracing point, wherein the improvement comprises: a. a peakhold circuit responsive to the error signal and producing a first output signal in response to an over-deflection of the tracing finger; b. a second order high pass filter connected to the peakhold circuit and producing a control signal; and c. a feed rate adjustment circuit connected to the second order high pass filter and responsive to the feed rate command signal for modifying the feed rate command signal as a function of the control signal whereby said feed rate command signal is immediately reduced in response to an overdeflection of the tracing finger and gradually increases to its predetermined value.

Claim 6

An automatic tracing apparatus comprised in part of a tracing head including a tracing finger for tracking a three-dimensional model and a tracing control producing therein an error signal representing an erroneous deflection in a tracing plane in a direction perpendicular to a model surface at a tracing point and a feed rate command signal having a magnitude representing a predetermined tracing velocity in the tracing plane tangent to the model surface at the tracing point, wherein the improvement comprises: a. a peakhold circuit responsive to the error signal and producing a first output signal in response to an over-deflection of the tracing finger; b. a second order high pass filter connected to the peakhold circuit and producing a control signal; and c. a feed rate adjustment circuit connected to the second order high pass filter and responsive to the feed rate command signal for modifying the feed rate command signal as a function of the control signal whereby said feed rate command signal is immediately reduced in response to an overdeflection of the tracing finger and gradually increases to its predetermined value.

Claim 7

The apparatus of claim 3 wherein the peak hold circuit comprises: a. a buffer amplifier having the quadrature error signal as an input; and b. a filter network having an input connected to the buffer amplifier and producing an output signal in response to a rapid increase in the magnitude of the quadrature error signal.

Claim 8

The apparatus of claim 4 wherein the peak hold circuit further comprises and impedance matching amplifier connected to the filter network and producing the first output signal in response to the output signal.