Path generating system for numerical control apparatus

Claim 2

Apparatus for generating axis command pulses to be supplied to first and second axis drives to produce a resultant circular movement of a member driven thereby in accordance with a predetermined circular path programmed in a program store, the program store including axes command data and feedrate command data, the apparatus comprising a path generator system operative to generate, in response to the program store axis command data, a train of axes command pulses for each axis to be supplied to the respective drives, and a control system operative to compare the program store feedrate command data with the generated axes command pulses and to produce feed pulses controlling the path generator system; said path generator system comprising: a data register for each of said axes, each register storing the command data for its respective axis from the program store; an error register; command pulse generating means effective to generate, for each feed pulse, an axis command pulse for said first axis when the error register is of one sign and an axis command pulse for said second axis when the error register is zero or of the opposite sign; and error register control means effective, upon the generation of each axis command pulse, to cause only the contents of the axis data register corresponding to the axis of the command pulse generated to be added into the error register when the error register is of said one sign and to be subtracted from the error register when the error register is of said opposite sign or zero, such as to cause the contents of the error register always to approach zero.

Claim 3

Apparatus as defined in claim 1, wherein, said error register control means is effective, upon the generation of each axis command pulse, to cause the data in its own axis data register to be added into the error register when the error register is negative and to be subtracted from the error register when the error register is positive or zero.

Claim 4

Apparatus as defined in claim 2, wherein the program store further includes data specifying the direction of rotation of the generated path, said patH generator system further comprising: means for adding the command data of the first axis into its respective data register and for subtracting the command data of its second axis from its respective data register when one direction of rotation is specified; and means for subtracting the command data of the first axis from its respective data register and for adding the command data of the second axis into its respective data register when the opposite direction of rotation is specified.

Claim 5

Apparatus as defined in claim 1 further including means to enable operation in the linear mode, said error register control means including means effective, upon the generation of each axis command pulse, to cause the data in the other axis data register to be added into the error register when the error register is negative, and to be subtracted from the error register when the error register is positive or zero.

Claim 6

Apparatus as defined in claim 4, the apparatus generating command pulses to be supplied also to a third-axis drive, said apparatus further including a second error register, said command pulse generating means being effective to generate, for each feed pulse, a first-axis command pulse when both of the error registers are negative, a second-axis command pulse when the first-mentioned error register is zero or positive, and a third-axis command pulse when the second-mentioned error register is zero or positive; said error register control means being effective: upon the generation of each first-axis command pulse, to add the second-axis data into the first-mentioned error register and the third-axis data into the second-mentioned error register; upon the generation of each second-axis control pulse, to subtract the first-axis data from the first-mentioned error register and to add the third-axis data into the second-mentioned error register; and upon the generation of each third-axis command pulse, to subtract the first-axis data and the second-axis data from the second-mentioned error register.

Claim 7

Numerical control equipment comprising apparatus for generating axes command pulses as defined in claim 1, an input medium receiving said program store in coded form, and at least two drives having mutually orthogonal axes of motion controlled by the generated axes command pulses to produce a resultant circular movement of the member driven by the drives in accordance with the path and feedrate programmed in the program store.

Claim 8

Apparatus for generating axis command pulses to be supplied to first and second axes drives to produce a resultant movement of a member driven thereby in accordance with a predetermined straight line or circular path and velocity programmed in a program store; the program store including: mode command data specifying a straight line or circular mode of path generation, axes command data specifying the programmed axis distances, and feedrate command data specifying the programmed vector velocities; the apparatus comprising a path generator system operative to generate, in response to the program store axis command data, a train of axes command pulses for each axis to be supplied to the respective drives, and a velocity control system operative to compare the program store feedrate command data with the generated axes command pulses and to produce feedrate pulses controlling the path generator system; said path generator system comprising: a data register for each of said axes, each register storing the command data for its respective axis from the program store; an error register; command pulse generating means effective to generate, for each feed pulse, an axis command pulse for said first axis when the error register is of one sign, and an axis command pulse for said second axis when the error register is of the opposite sign or zero; mode selection means receiving the mode command data and enabling operation in accordance with a circular mode or in accordance with a linear mode; and error register control means effective, upon the geneRation of each command pulse for said first axis while the apparatus is operating in accordance with the linear mode, to cause the data in the other axis data register to be added into the error register when the error register is of said one sign and to be subtracted from the error register when the error register is of said opposite sign or zero; said error register control means being effective, upon the generation of each command pulse for said first axis while the apparatus is operating in accordance with the circular mode, to cause the data in its own axis data register to be added into the error register when the error register is of said one sign and to be subtracted from the error register when the error register is of said opposite sign or zero, such as to cause the contents of the error register always to approach zero.

Claim 9

Apparatus for generating axis command pulses to be supplied to first and second axes drives to produce a resultant movement of a member driven thereby in accordance with a predetermined straight line or circular path and velocity programmed in a program store; the program store including: mode command data specifying a straight line or circular mode of path generation, axes command data specifying the programmed axis distances, and feedrate command data specifying the programmed vector velocities; the apparatus comprising a path generator system operative to generate, in response to the program store axis command data, a train of axes command pulses for each axis to be supplied to the respective drives, and a velocity control system operative to compare the program store feedrate command data with the generated axes command pulses and to produce feedrate pulses controlling the path generator system; said path generator system comprising: a data register for each of said axes, each register storing the command data for its respective axis from the program store; an error register; command pulse generating means effective to generate, for each feed pulse, an axis command pulse for said first axis when the error register is of one sign, and an axis command pulse for said second axis when the error register is of the opposite sign or zero; mode selection means receiving the mode command data and enabling operation in accordance with a circular mode or in accordance with a linear mode; and error register control means effective, upon the geneRation of each command pulse for said first axis while the apparatus is operating in accordance with the linear mode, to cause the data in the other axis data register to be added into the error register when the error register is of said one sign and to be subtracted from the error register when the error register is of said opposite sign or zero; said error register control means being effective, upon the generation of each command pulse for said first axis while the apparatus is operating in accordance with the circular mode, to cause the data in its own axis data register to be added into the error register when the error register is of said one sign and to be subtracted from the error register when the error register is of said opposite sign or zero, such as to cause the contents of the error register always to approach zero.