Digital tool size compensation for numerical control

Claim 2

In a numerically controlled machine having computing and storage means, operative to control the movement of a cutter tool to thereby machine an article in response to a segmented profile program defined with respect to at least two perpendicular coordinate axes, each segment of said program including a block of digital data for each axis, each block of data being individually indicative of the profile along one of said coordinate axes, and wherein said computing and storage means converts said data blocks into sets of control pulses operative to actuate output drives individually associated with each coordinate axes to control the relationship between said cutter tool and said article; a system for providing compensation for the size of said cutter tool comprising: means for inserting information relating to size of said cutter tool into said numerically controlled machine, means responsive to said information relating to the size of said cutter for generating a radius pulse proportional to said information; means responsive to said radius pulse rate and said blocks of digital data for generating at least two offset pulse rates having a predetermined relationship to said radius pulse rates and said profile segment; and means responsive to said two offset pulse rates for generating compensation pulses operative to offset said output driVes thereby compensating for the size of said cutter tool.

Claim 3

The system of claim 1 wherein said storage means is capable of storing information relating to a plurality of tool sizes, said means for inserting further including: means for digitally inserting into said storage, a plurality of different cutter tool sizes; and means for selecting from said stored plurality of tool sizes, information relating to the size of the cutter being used.

Claim 4

The system of claim 2 wherein said profile is defined in more than two coordinate axes and said numerical control machine has an output drive for each axis about which said profile is defined, said system further including: means for generating axes signals indicative of each coordinate axes about which the cutter compensation is to be active; means responsive to said axies signals for transferring, to said means for generating pulse rates, the data blocks indicative of said axes; and means responsive to said axes signals for applying said compensation pulses to the output drives associated with said axes.

Claim 5

The system of claim 3 wherein said segmented profile program includes an assumed cutter size, said information relating to the cutter size is a radius value, said radius value is the difference between the assumed cutter radius and the actual cutter radius and said means for inserting further includes means for inserting the sign of said difference.

Claim 6

The system of claim 4 wherein said means for generating a radius pulse rate includes: means for storing said selected information relating to said cutter size; and means for converting said stored information into digital radius pulses at a rate proportional to the size of said tool.

Claim 7

The system as claimed in claim 4 wherein said compensation pulse generating means includes: means for generating compensation pulse rates proportional to a number of stored compensation pulses; and means for comparing said offset pulse rates with said compensation pulse rates for generating compensation pulses when said compensation pulse rates are different from said offset pulse rates, and said compensation pulses are continuously input into said compensation pulse generating means storage until said compensation pulse rate is equal to said offset pulse rate.

Claim 8

The system of claim 4 wherein said means for generating offset pulse rates includes: means for storing said transferred blocks of data; means for converting the stored data into two sets of offset pulses, wherein said first set of offset pulses are generated at a rate Delta A proportional to the block of data indicative of the profile segment along one coordinate axes, and said second set of offset pulses are generated at a rate Delta proportional to the block of data indicative of the profile segment along said second coordinate axes; and means for computing a predetermined relationship between said offset pulse rates and said radius pulse rate and for controlling the rates at which said offset pulses are generated to satisfy said predetermined relationship.

Claim 9

The system as claimed in claim 7 wherein said predetermined relationship is given by the equation A2 + B2 - r2 0 wherein A is the number of pulses generated by said pulse rate generating means in response to the data block indicative of the profile segment along one of said axes, B is the number of pulses generated by said pulse rate generating means in response to the data block indicative of the profile segment along another of said axes, and r is the number of radius pulses generated, said means for computing includes: means for storing A, B, and r pulses generated by the respective pulse rate generators; means for squaring the stored A, B, and r pulses to generate A2, B2 and r2; and means for summing A2 and B2 with -r2 and for generating an add signal when thE sum is a negative number, wherein said add signal is operative to control the rate at which said A and B pulses are generated.

Claim 10

The system as claimed in claim 8 wherein said compensation pulse rate generating means includes: first storage means for storing compensation pulses; first generating means for generating pulses at a rate Delta a proportional to the number of compensation pulses stored in said first storage means; second storage means for storing compensation pulses; and second generating means for generating pulses at a rate Delta b proportional to the number of compensation pulses stored in said second storage means.

Claim 11

The system as claimed in claim 9 wherein said compensation pulse generating means comprises: first comparing means for comparing said Delta A offset pulse rate with said Delta a compensation pulse rate for generating a first signal when Delta A is larger than Delta a, and a second signal when Delta a is larger than Delta A and no signal when Delta A Delta a; means responsive to said first and second signals generated by said first comparing means for generating compensation pulses, a signal indicative of which of said two pulse rates, Delta A or Delta a, is larger and a signal operative to index the generated compensation pulses into said first compensation pulse storage means until said pulse rate Delta a is equal to said pulse rate Delta A; second comparing means for comparing a Delta B offset pulse rate with said Delta b compensation pulse rate and for generating a first signal when Delta B is larger than Delta b and a second signal when Delta b is larger than Delta B; and means responsive to said first and second signals generated by said second comparing means for generating compensation pulses, a signal indicative of which of said two pulse rates Delta B or Delta b, is larger and a signal operative to index the generated compensation pulses into said second compensation pulse storage means until pulse rate Delta b is equal to pulse rate Delta B.

Claim 12

In a numerically controlled machine having computing and storage means operative to control the movement of a cutter tool to thereby machine an article in response to a segmented profile program defined with respect to at least two perpendicular coordinate axes, each segment of said program including a block of digital data for each axes, each block of data being individually indicative of the profile along one of said coordinate axes and wherein said computing and storage means converts said data blocks into sets of control pulses operative to actuate output drives individually associated with each coordinate axes to control the relationship between said cutter tool and said article, a method for providing compensation for the size of said cutter tool comprising: inserting information relating to the size of the cutter tool into said numerically controlled machine; generating a tool size pulse rate proportional to said inserted information; generating at least two offset pulse rates, having a predetermined relationship to said digital blocks of data and to said tool size pulse rate; generating from said at least two offset pulse rates at least two sets of compensation pulses, one set of compensation pulses individually associated with each of said offset pulse rates; applying said sets of compensation pulses to said output drives.

Claim 13

In a numerically controlled machine having computing and storage means operative to control the movement of a cutter tool to thereby machine an article in response to a segmented profile program defined with respect to at least two perpendicular coordinate axes, each segment of said program including a block of digital data for each axes, each block of data being individually indicative of the profile along one of said coordinate axes and wherein said computing and storage means converts said data blocks into sets of control pulses operative to actuate output drives individually associated with each coordinate axes to control the relationship between said cutter tool and said article, a method for providing compensation for the size of said cutter tool comprising: inserting information relating to the size of the cutter tool into said numerically controlled machine; generating a tool size pulse rate proportional to said inserted information; generating at least two offset pulse rates, having a predetermined relationship to said digital blocks of data and to said tool size pulse rate; generating from said at least two offset pulse rates at least two sets of compensation pulses, one set of compensation pulses individually associated with each of said offset pulse rates; applying said sets of compensation pulses to said output drives.

Claim 14

The method of claim 11 wherein said storage means is capable of storing information relating to a plurality of tool sizes, said step of inserting further includes the steps of: inserting into said storage a plurality of different tool sizes; and selecting from said stored plurality of tool sizes, information relating to the size of the tool being used in the numerically controlled machine.

Claim 15

The method of claim 12 wherein said profile program is defined in more than two coordinate axes and said numerically controlled machinE has an output drive for each axis about which said profile is defined; said step of inserting further includes the step of inserting information relating to each axes in which the cutter compensation is to be operative; said step of generating offset signals further includes the step of selecting the data blocks indicative of the axes information so inserted; and said method further includes the step of transferring said generated compensation pulses to the output drives associated with said inserted axes information.

Claim 16

The method of claim 11 wherein said segmented profile program includes an assumed tool size, said step of inserting comprises the step of inserting a radius value, said radius value being the difference between the size of the actual tool and the size of said assumed tool and the sign of the difference between the assumed and actual tool size.

Claim 17

The method of claim 14 wherein said step of generating a tool size pulse rate comprises the steps of: storing said selected information relating to the size of said tool; and generating from said stored information a pulse rate proportional to said stored information.

Claim 18

The method of claim 15 wherein said step of generating offset pulse rates comprises the steps of: transferring the data blocks associated with said axes information to a storage, where said data blocks are stored; generating two offset pulse rates, one rate Delta A proportional to the data block associated with one of the selected axes and the second pulse rate Delta B proportional to the data block associated with the other selected axes; computing from said tool size pulse rate, and from said Delta A and Delta B offset pulse rates a predetermined relationship; and generating an add signal when said computed predetermined relationship is not satisfied, said add signal operative to enable said step of generating to generate said Delta A and said Delta B offset pulse rates proportional to the data blocks of said selected axes and at rates satisfying said predetermined relationship.

Claim 19

The method of claim 16 wherein said step of generating compensation pulses comprises the steps of: storing previously generated compensation pulses; generating a compensation pulse rate proportional to a number of stored compensation pulses; and comparing said compensation pulse rates to said offset pulse rates to generate compensation pulses when said offset and compensation pulse rates are different.

Claim 20

The method of claim 16 wherein said predetermined relationship is given by the equation A2 + B2 - r2 0 wherein A is the sum of the pulses generated by said Delta A pulse rate after a given period of time, Delta B is the sum of the pulses generated by said Delta B pulse rate after the same period of time, and r is the sum of tool size pulses generated by the pulse rate Delta r after the same period of time, said step of computing and said step of generating an add signal comprises the steps of: storing said A, B, and r pulses; squaring at predeterminable intervals of time the stored pulses A, B, and r to generate A2, B2, and r2 values; summing A2 and B2 with -r2 to generate a sum signal; and generating an add signal when said sum signal is negative and terminating said add signal when said sum signal is not negative.

Claim 21

The method of claim 18 wherein said step of generating compensation pulse rates comprises the steps of: storing a first set of compensation pulses; generating pulses at a rate Delta a proportional to the number of pulses in said first set of stored compensation pulses; storing a second set of compensation pulses; generating pulses at a rate Delta b proportional to the number of pulses in said second set of stored compensation pulses; further said step of comparing includes: comparing said Delta A offset pulse rate with said Delta a compensation pulse rate and generating a first signal when Delta A is larger than Delta a and a second signal when Delta a is larger than Delta A; and comparing said Delta B offset pulse rate with said Delta b compensation pulse rate and generating a first signal when Delta B is larger than Delta b and a second signal when Delta b is larger than Delta B; generating in response to said first and second signals resulting from the comparing said Delta A and Delta a pulse rates, an A Compensation Pulse, a signal indicative of which of said two pulse rates, Delta A or Delta b is larger, and a signal operative to index the stored number of compensation pulses associated with the generation of Delta a pulses; generating in response to said first and second signals resulting from the comparing of said Delta B to Delta b pulse rates, a B compensation pulse, a signal indicative of which pulse rate, Delta B or Delta b, is larger and a signal operative to index the stored number of compensation pulses associated with the generation of Delta b pulses; and wherein said stored number of compensation pulses associated with the generation of Delta a and Delta b pulses are continuously indexed until said a compensation pulse rate is equal to said Delta A offset pulse rate, and said Delta b compensation pulse rate is equal to said Delta B offset pulse rate.

Claim 22

In a numerically controlled machine, wherein: a program profile is defined in terms of at least two perpendicular coordinate axes; said profile is divided into program segments, each segment being defined by a mathematical expression, frequently different from the expression for the immediately adjacent segments; the mathematical expression for each of said segments is converted into digital segment data and said digital segment data is programmed into computation and storage means, each of said profile segments being represented by one block of data; a method of providing cutter tool size compensation in said numerically controlled system comprising of steps of: defining an axes offset for said cutter tool satisfying the equation: A2 + B2 - r2 0 wherein A is the axes offset along one of said two perpendicular coordinate axes and B is the axes offset along the other coordinate axes and r is the radius of the cutting tool wherein the solution of the equation A2 + B2 - r2 0 further satisfying the relationship: A/B - Delta Y/ Delta X where Delta X is the mathematical expression representative of the digital segment data along said one coordinate axes and Delta Y is the mathematical expression representative of the digital segment data along said other coordinate axes; providing an offset algorithmm for each of said axes offsets, said algorithm being expressed in terms of pulse rates Delta A, Delta B and Delta r wherein pulse rate Delta A is proportional to the mathematical expression Delta Y, pulse rate Delta B proportional to the mathematical expression Delta X and pulse rate Delta r proportional to the cutter radius r, and, providing an algorithm for converting said Delta A and Delta B pulse rates into axes offsets A and B respectively; providing storage and computation circuitry for generating Delta A,, Delta B and Delta r pulse rates, satisfying the equations: Delta A2 + Delta B2 - Delta r2 0 and Delta A/ Delta B - Delta Y/ Delta X and for converting said pulse rates Delta A and Delta B to offsets A and B respectively, satisfying the equations: A2 + B2 - r2 0 and A/B - Delta V/ Delta X and; initiating said cutter tool compensation by injecting information relating to the radius of the cutter To be used and said digital segment data into said computation and storage means and allowing said electronic circuitry to calculate the required offset in accordance with said segment data, said information relating to the size of said tool and said offset algorithms.

Claim 23

In a numerically controlled machine, wherein: a program profile is defined in terms of at least two perpendicular coordinate axes; said profile is divided into program segments, each segment being defined by a mathematical expression, frequently different from the expression for the immediately adjacent segments; the mathematical expression for each of said segments is converted into digital segment data and said digital segment data is programmed into computation and storage means, each of said profile segments being represented by one block of data; a method of providing cutter tool size compensation in said numerically controlled system comprising of steps of: defining an axes offset for said cutter tool satisfying the equation: A2 + B2 - r2 0 wherein A is the axes offset along one of said two perpendicular coordinate axes and B is the axes offset along the other coordinate axes and r is the radius of the cutting tool wherein the solution of the equation A2 + B2 - r2 0 further satisfying the relationship: A/B - Delta Y/ Delta X where Delta X is the mathematical expression representative of the digital segment data along said one coordinate axes and Delta Y is the mathematical expression representative of the digital segment data along said other coordinate axes; providing an offset algorithmm for each of said axes offsets, said algorithm being expressed in terms of pulse rates Delta A, Delta B and Delta r wherein pulse rate Delta A is proportional to the mathematical expression Delta Y, pulse rate Delta B proportional to the mathematical expression Delta X and pulse rate Delta r proportional to the cutter radius r, and, providing an algorithm for converting said Delta A and Delta B pulse rates into axes offsets A and B respectively; providing storage and computation circuitry for generating Delta A,, Delta B and Delta r pulse rates, satisfying the equations: Delta A2 + Delta B2 - Delta r2 0 and Delta A/ Delta B - Delta Y/ Delta X and for converting said pulse rates Delta A and Delta B to offsets A and B respectively, satisfying the equations: A2 + B2 - r2 0 and A/B - Delta V/ Delta X and; initiating said cutter tool compensation by injecting information relating to the radius of the cutter To be used and said digital segment data into said computation and storage means and allowing said electronic circuitry to calculate the required offset in accordance with said segment data, said information relating to the size of said tool and said offset algorithms.

Claim 24

In a numerically controlled machine, wherein: a program profile having an assumed cutter tool radius is defined in terms of at least two perpendicular coordinate axes; said profile is divided into program segments, each segment being defined by a mathematical expression, frequently different from the expression for the immediately adjacent segments; the mathematical expression for each of said segments is converted into digital segment data and said digital segment data is programmed into computation and storage means, each of said profile segments being represented by one block of data; a method of providing cutter tool size compensation in said numerically controlled system comprising the steps of: defining an axes offset for said cutter tool, satisfying the equation: A2 + B2 - r2 0 wherein A is the axes offset along one of said two perpendicular coordinate axes and B is the axes offset along the other coordinate axes and r is the difference between the radius of the actual cutting tool and radius of the assumed cutting tool, wherein the solution of the equation A2 + B2 - r2 0 further satisfying the relationship: A/B - Delta Y/ Delta X where Delta X is the mathematical expression represented of the digital segment data along said one coordinate axes and Delta Y is the mathematical expression represented of the digital segment data along said other coordinate axes; providing an offset algorithm for each of said axes offsets, said algorithm being expressed in terms of pulse rates, Delta A, Delta B and Delta r wherein pulse rate Delta A is proportional to the mathematical expression Delta Y, pulse rate Delta B is proportional to the mathematical expression Delta X and pulse rate Delta r proportional to the difference between the actual cutter radius and the assumed tool radius, and, providing an algorithm for converting said Delta A and Delta B pulse rates into axes offsets A and B respectively; providing storage and computation circuitry for generating Delta A, Delta B and Delta r pulse rates satisfying the equations: Delta A2 + Delta B2 - Delta r2 0 and Delta A/ Delta B - Delta Y/ Delta X and for converting said pulse rates Delta A and Delta B to offsets A and B respectively satisfying the equations: A2 + B2 - r2 + 0 and A/B - Delta Y/ Delta X and; initiating said cutter tool compensation by injecting information relating to the radius of the cutter to be used and said digital segment data into said computation and storage means and allowing said electronic circuitry to calculate the required offset in accordance with said segment data, said information relating to the difference between the actual and assumed size of said tool, and said offset algorithms.

Claim 25

In a numerically controlled machine, wherein: a program profile having an assumed cutter tool radius is defined in terms of at least two perpendicular coordinate axes; said profile is divided into program segments, each segment being defined by a mathematical expression, frequently different from the expression for the immediately adjacent segments; the mathematical expression for each of said segments is converted into digital segment data and said digital segment data is programmed into computation and storage means, each of said profile segments being represented by one block of data; a method of providing cutter tool size compensation in said numerically controlled system comprising the steps of: defining an axes offset for said cutter tool, satisfying the equation: A2 + B2 - r2 0 wherein A is the axes offset along one of said two perpendicular coordinate axes and B is the axes offset along the other coordinate axes and r is the difference between the radius of the actual cutting tool and radius of the assumed cutting tool, wherein the solution of the equation A2 + B2 - r2 0 further satisfying the relationship: A/B - Delta Y/ Delta X where Delta X is the mathematical expression represented of the digital segment data along said one coordinate axes and Delta Y is the mathematical expression represented of the digital segment data along said other coordinate axes; providing an offset algorithm for each of said axes offsets, said algorithm being expressed in terms of pulse rates, Delta A, Delta B and Delta r wherein pulse rate Delta A is proportional to the mathematical expression Delta Y, pulse rate Delta B is proportional to the mathematical expression Delta X and pulse rate Delta r proportional to the difference between the actual cutter radius and the assumed tool radius, and, providing an algorithm for converting said Delta A and Delta B pulse rates into axes offsets A and B respectively; providing storage and computation circuitry for generating Delta A, Delta B and Delta r pulse rates satisfying the equations: Delta A2 + Delta B2 - Delta r2 0 and Delta A/ Delta B - Delta Y/ Delta X and for converting said pulse rates Delta A and Delta B to offsets A and B respectively satisfying the equations: A2 + B2 - r2 + 0 and A/B - Delta Y/ Delta X and; initiating said cutter tool compensation by injecting information relating to the radius of the cutter to be used and said digital segment data into said computation and storage means and allowing said electronic circuitry to calculate the required offset in accordance with said segment data, said information relating to the difference between the actual and assumed size of said tool, and said offset algorithms.