Deceleration control for tracer control equipment

Claim 2

Tracer control equipment controlling a relative feed rate, between a model and a tracer head tracing the surface of the model, in accordance with a displacement signal output by the tracer head, said tracer control equipment comprising: detecting means for detecting variation of the displacement signal over time; decision means for comparing a plurality of threshold values of different levels with the detected variation of the displacement signal and for determining a region, defined by the threshold values, including the detected variation of the displacement signal; and deceleration control means for reducing without increasing the relative feed rate between the tracer head and the model to a value corresponding to the region determined by said decision means during a period from a first time when the variation of the displacement signal is determined by the decision means to have exceeded the threshold value of the lowest level of the threshold values to a second time when the detected variation of the displacement signal is determined to be smaller than the threshold value of the lowest level.

Claim 3

Tracer control equipment as recited in claim 1, wherein said detecting means comprises means for supplying a first derivative of the displacement signal as the detected variation of the displacement signal.

Claim 4

Tracer control equipment as recited in claim 1, wherein said deceleration control means comprises: region changing detection means for detecting when the region determined by said decision means changes; and speed control means for controlling the relative feed rate between the tracer head and the model in dependence upon changes in the region detected by said region changing detection means.

Claim 5

Tracer control equipment controlling a relative feed rate between a model and a tracer head tracing the surface of the model, in accordance with a displacement signal output by the tracer head, said tracer control equipment comprising: detecting means for detecting variation of the displacement signal over time; decision means for comparing a plurality of threshold values of different levels with the detected variation of the displacement signal and for determining a region, defined by the threshold values, including the detected variation of the displacement signal; and deceleration control means for reducing the relative feed rate between the tracer head and the model to a value corresponding to the region determined by said decision means during a period from a first time, when the variation of the displacement signal is determined by the decision means to have exceeded the threshold value of the lowest level of t he threshold value, to a second time, when the detected variation of the displacement signal is determined to be smaller than the threshold value of the lowest level, said deceleration control means including rise and fall detectors, operatively connected to said decision means, each rise and fall detector respectively detecting when the variation of the displacement signal first exceeds and first returns below a corresponding threshold value; and speed control means for controlling the relative feed rate between the tracer head and the model in dependence upon changes in the region identified by said rise and fall detectors.

Claim 6

Tracer control equipment controlling a relative feed rate between a model and a tracer head tracing the surface of the model, in accordance with a displacement signal output by the tracer head, said tracer control equipment comprising: detecting means for detecting variation of the displacement signal over time; decision means for comparing a plurality of threshold values of different levels with the detected variation of the displacement signal and for determining a region, defined by the threshold values, including the detected variation of the displacement signal; and deceleration control means for reducing the relative feed rate between the tracer head and the model to a value corresponding to the region determined by said decision means during a period from a first time, when the variation of the displacement signal is determined by the decision means to have exceeded the threshold value of the lowest level of t he threshold value, to a second time, when the detected variation of the displacement signal is determined to be smaller than the threshold value of the lowest level, said deceleration control means including rise and fall detectors, operatively connected to said decision means, each rise and fall detector respectively detecting when the variation of the displacement signal first exceeds and first returns below a corresponding threshold value; and speed control means for controlling the relative feed rate between the tracer head and the model in dependence upon changes in the region identified by said rise and fall detectors.

Claim 7

Tracer control equipment as recited in claim 4, wherein said speed control means comprises counting means for producing a count indicating the highest threshold value exceeded for each time the lowest threshold value is exceeded; reset means for resetting said counting means when the variation of the displacement signal returns below the lowest threshold value; and attenuation means for reducing the relative feed rate in dependence upon the count produced by said counting means.