EP0406784A2
Expired / Lapsed
EP
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Electronic polynomial interpolation device for numeric controls of machine tools, particularly milling machines for the machining of dies, and machine comprising said device
Assignee: Advanced Data Processing ADP SRL
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Filing: 1990-07-03
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Granted: —
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Expires: 2010-07-03
Abstract
Abstract The device comprises a first section (25) , which comprises logic circuit means which generate the law of motion along the machine operative trajectory arc, and a second section with a set of three digital polynomial generators (27-28-29), each of which receives from the motion law generator means the instantaneous value of the curvilinear coordinate and, from an external processing unit, the polynomial coefficients related to the trajectory arc to be generated and the sampling and sub-sampling pulses; the polynomial generators of the second section are suitable for providing, on the respective outputs, the corresponding components of the instantaneous speed vectors of each point of the trajectory, generated by adding and multiplying the polynomial coefficients and the curvilinear coordinate.
Inventors
- 👤 Piera Levi Montalcini
- 👤 Antonio Racciu
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 01:54
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/41; G05B19/4103; G05B2219/00; G05B2219/30; G05B2219/34; G05B2219/34142
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
142 words
Polynomial interpolation device for numeric controls of machine tools, particularly milling machines for the machining of dies, characterized in that it comprises a first section which includes logic circuit means for generating the law of motion along the machine operative trajectory arc and a second section with a set of three digital polynomial generators, each of which receives from the motion law generators the instantaneous value of the curvilinear coordinate and, from an external processing unit, the polynomial coefficients related to the trajectory arc to be generated, and the sampling and sub-sampling pulses; the polynomial generators of the second section being suitable for providing, on the respective outputs, the corresponding components of the instantaneous position vectors and of the instantaneous speed vectors of each point of the trajectory, generated by addition and multiplication of the polynomial coefficients and of the curvilinear coordinate.
Claim 2
Dependent Claim
142 words
Polynomial interpolation device for numeric controls of machine tools, particularly milling machines for the machining of dies, characterized in that it comprises a first section which includes logic circuit means for generating the law of motion along the machine operative trajectory arc and a second section with a set of three digital polynomial generators, each of which receives from the motion law generators the instantaneous value of the curvilinear coordinate and, from an external processing unit, the polynomial coefficients related to the trajectory arc to be generated, and the sampling and sub-sampling pulses; the polynomial generators of the second section being suitable for providing, on the respective outputs, the corresponding components of the instantaneous position vectors and of the instantaneous speed vectors of each point of the trajectory, generated by addition and multiplication of the polynomial coefficients and of the curvilinear coordinate.
Claim 3
Dependent Claim
32 words
Device according to claim 1, characterized in that said first section generates a speed diagram according to the law of uniformly accelerated motion across the ends of the trajectory arc being considered.
Claim 4
Dependent Claim
27 words
Device according to claim 2, characterized in that the logic circuit means of the first section generate the speed diagram by adding or subtracting constant-value acceleration steps.
Claim 5
Dependent Claim
43 words
Device according to claim 1, characterized in that the logic circuit means of the first section are suitable for calculating the instantaneous value of the curvilinear coordinate of the trajectory by integrating the diagram of the speed which represents the law of motion.
Claim 6
Dependent Claim
33 words
Device according to claim 1, characterized in that the polynomial coefficients related to the trajectory arc to be generated are produced by a microprocessor-based external auxiliary system capable of mathematically defining a surface.
Claim 7
Dependent Claim
141 words
Device according to claims 1 to 4, characterized in that the logic circuit means of said first section comprise a first binary adder which performs, at each sampling interval, the sum of the speed related to the preceding instant and of the positive or negative acceleration steps which are preset at the outputs of respective selectors, a first binary accumulator in which the value of the sum is stored, a second binary adder which integrates the speed related to a given instant by adding to said speed the curvilinear coordinate related to the preceding instant, which is stored in a second binary accumulator, and a binary comparator which compares the curvilinear coordinate at the instant being considered and the total curvilinear distance in order to recognize the end of the trajectory arc and to generate a signal indicating a new arc.
Claim 8
Dependent Claim
73 words
Device according to claim 6, characterized in that said logic circuit means of the first section furthermore comprise a binary multiplier circuit which is suitable for calculating, at each sampling interval, the square of the generated speed, and a binary comparator which compares said squared value with a control value to provide a criterion for activating said selectors depending on whether acceleration or deceleration is to be performed along the sub-trajectory being considered.
Claim 9
Dependent Claim
147 words
Device according to claims 6 and 7, characterized in that the logic circuit means of said first section furthermore comprise a logic circuit for generating said control value which comprises a binary subtractor which subtracts, at each sampling interval, the length of the sub-trajectory arc from the curvilinear coordinate, a first binary multiplier which performs the product of said subtraction and of twice the acceleration step, a binary adder which adds the output value of the multiplier to the square of the speed of exit from the sub-trajectory arc, two further binary multipliers which calculate the square of the product of the maximum allowed speed and of a percentage factor, and a digital comparator which compares the output of the first multiplier with that of the adder to drive two selectors which assign the lowest of the two values which enter said comparator to the comparison value.
Claim 10
Dependent Claim
83 words
Device according to claim 1, characterized in that each polynomial generator of the second section comprises a shift register for the parallel accumulation of the polynomial coefficients and wherein the serial output of the shift register is operatively connected to a chain which comprises a binary multiplier, a binary adder and a binary accumulator which are suitable for calculating the polynomial which represents the trajectory reduced to a recursive form of additions and multiplications of the polynomial coefficients and of the curvilinear coordinate.
Claim 11
Dependent Claim
39 words
Device according to claim 6, characterized in that the length of the registers of the polynomial generators is proportionate to the degree of the polynomial to be generated and is equal to the degree of said polynomial + 1.
Claim 12
Dependent Claim
36 words
Device according to claim 9, characterized in that the polynomial coefficients are accumulated in the shift register at each sampling interval and are transferred in a scalar manner to the binary adder at each sub-sampling pulse.
Claim 13
Dependent Claim
41 words
Device according to claim 10, characterized in that the binary multiplier performs, at each sub-sampling interval, the product of the curvilinear coordinate and of the output value of the adder related to the preceding interval, which is stored in said accumulator.
Claim 14
Dependent Claim
71 words
Device according to claim 1 and any one of the preceding claims, characterized in that it comprises a microprocessor which is programmed to generate the law of motion along the machine operative trajectory arc, to integrate the speed diagram related to said law of motion, to obtain the curvilinear coordinate of said trajectory and to calculate the polynomial which represents the trajectory reduced to a recursive form of additions and multiplications.
Claim 15
Dependent Claim
117 words
Machine tool, particularly milling machine for the machining of dies, characterized in that it comprises a polynomial interpolator interfaced on one side with a system for generating polynomial coefficients and with said machine tool on another side, and in that the polynomial interpolator comprises a first section, which generates the curvilinear coordinate of the trajectory arc of the machine tool by integrating the speed diagram related to the preset law of motion, and a second section with a set of three polynomial generators, each of which comprises a multiplier, an adder and an accumulator which are suitable for calculating the polynomial which represents the trajectory of said tool reduced to a recursive form of additions and multiplications.
Claim 16
Dependent Claim
117 words
Machine tool, particularly milling machine for the machining of dies, characterized in that it comprises a polynomial interpolator interfaced on one side with a system for generating polynomial coefficients and with said machine tool on another side, and in that the polynomial interpolator comprises a first section, which generates the curvilinear coordinate of the trajectory arc of the machine tool by integrating the speed diagram related to the preset law of motion, and a second section with a set of three polynomial generators, each of which comprises a multiplier, an adder and an accumulator which are suitable for calculating the polynomial which represents the trajectory of said tool reduced to a recursive form of additions and multiplications.
Claim 17
Dependent Claim
111 words
Machine tool according to claim 14, characterized in that the theoretical speed outputs of the polynomial generators drive, with converter and amplifier units interposed, the motors of respective units for moving the machine tool, and in that each movement unit comprises a rule and an optical sensor which co-operate and are suitable for providing the actual position of the tool along the related coordinated machine axis and a set of three logic circuits inserted in respective control loops, each of which compares the actual positions along the corresponding machine axis with the theoretical ones provided by the polynomial generators in order to generate a corresponding correction signal in terms of speed.
Claim 18
Dependent Claim
70 words
Machine tool according to claim 15, characterized in that the logic circuit of each control loop comprises a binary subtractor which calculates the difference between the theoretical position and the actual one, a binary multiplier which multiplies the result of the subtraction by the gain of the respective control loop, and an adder which adds the respective theoretical speed at the instant being considered to the result of said product.
References Cited (Backward Citations)
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