SU714356A1 - Circular interpolator - Google Patents

Description

{54) CIRCULAR INTERPOLATOR

one

The invention relates to the field of computer technology and can be used in software control systems and graphic information builders.

The iji interpolator, which operates according to the evaluation function method and contains an adder, coordinate registers, a control unit and ventilation units, is known.

The disadvantage of such an interpolator is limited functionality.

The closest technical solution to the invention is a circular interpolator containing an adder of the evaluation function, the output and the first input of which are connected respectively to the first input and the first output of the control unit, and the second input to the output of the first valve block, connected by the first input to the output of the first coordinate the register, the input of which and the second input of the first valve block are connected

to the second output of the control unit, and the second coordinate register 2J.

Such an interpolator approximates a circle with a step line consisting of single increments in the directions of the coordinate axes.

The accuracy of this interpolator is insufficient.

The purpose of the invention, an increase in the accuracy of the interpolator, is achieved by the introduction of a switch, a second fan valve and a reversible counter. The first input of the counter is connected to the output of the first valve block, the second and third inputs to the third and fourth outputs of the control unit, respectively, and the output to the BTOp6Nty input of the control unit. The fifth and sixth outputs of the control unit are connected respectively to the first input of the second valve block and to the first input of the switch connected by the second input to the first output of the second coordinate register, and output to the third input of the evaluator function, the third, fourth and fifth inputs of KCiTOporo are connected respectively to the sixth, seventh and first exits of the control unit. The second one in the second coordinate register is connected to the second input of the second block and the third output and the input with the third input and the eighth output of the control unit, respectively, the Interpolator approximates a circle with an arbitrary, not necessarily quantization, radius, which reduces the size interpolations due to rounding. The accuracy of the approximation of a given circle is enhanced by calculating the evaluation function in a coordinate system that is displaced relative to the system in which it builds from the approximating line. If we denote 15 — the given (unquantized) radius of the circle, e (Jj is the closest quantized value, then the mixing along the axes will be (0.5 + & 12) Vl and (O, 3 –dT2) H, where the pitch is. quantizing, A. & R K- Having made the necessary transformations and admissible simplifications, we obtain that, with a step along the first axis Y, the function U is estimated; 1r; 7rrUjr2 -2j9 with a step of tue i ji 13 1. .-. x. where j is the number of steps along the y axis, the number of steps along the x axis, and the initial value of the estimated fuqiu UQ is most simply calculated at a point on one of the axes. It contains the adder of the evaluation function it, the first 2 and second 3 coordinate registers, the first block of valves 4j switch 5, the reversible counter 6s, the second block of valves 7, and the control unit S "Interpolator works as follows 3, a negative radius value of 15 is entered. (In the additional code), the adder Is register 2 to the meter 6 is in the zero state. In the first clock cycle from the output of the register 3 to the counter 6 the value is entered. d in the adder 1 with the entry of the register b the contents of the remaining bits are entered and, if in the highest bit, de.D. (at the third output of register 3) is zero, from the adder 1, the fourth input subtracts the unit from the (P + 1) -th bit, where is the number of bits T. Thus, the value is entered - (fk, In the next clock cycle, if in the higher order - LR adder 1 is one, or subtracted if - the null contents of register 3, is shifted towards the lower order bits by (VI 1) bits (BbRHTaHHe is produced by adding the inverted contents of register 3 to the contents of adder 1 and by adding a unit to its least significant bit - to the first input). a unit is added to counter 6 if there is a unit in the high-order de D1, or subtraction if there is zero. The same clock cycles are repeated until counter-6 is zeroed. The register is added in each clock with the unit in the second discharge of adder 1. 2, shift-: o for one bit in the direction of the senior (i.e. multiplied by two) to the contents of summ-ora 1, adding one to the lower-order bit of the register 2 in ()) - / bit of the adder 1 (for fifth intake; l is the signal of a unit increment along the X axis. At zero, in the significant digit of adder 1, the contents of register 3, shifted by one bit towards the higher bits, are added to, the (P + 1) -th bit of register 3 and ( And + 2) is the bit of the adder 1 and the output signal of a single increment along the Y axis. When adding the doubled value of the contents of the register 3 to the contents of the adder 1, the units of the lower bits from the switch 5 are fed to its (P + 1). The above described work of the interpolator according to the simplified evaluation function, however, if necessary, it can work on the evaluation function obtained in general form. The accuracy of the proposed interpolator is improved. The interpolation error in the general case does not exceed the value of nf2 (1 + 1/2) / 2, and the increase in accuracy is achieved without a decrease in the interpolation step, which is associated with a sharp decrease in speed. When approximating a circle with a quantized radius, the interpolation error does not exceed: 11/2/2 and is minimally possible.

Claims (2)

1. USSR author's certificate 20 No. 401964, class QO5 B 19/18, 1973. 2. Agursky, MS, et al. Numerical program ynpiaeneHHe. M., Mechanical Engineering, 1966, p. 178-179 (prototype). FGD