(57) Abstract:Usage: as a functional Converter to calculate the values of the functions sin X when the value of the argument Oh, 7854. Goal: increase measurement accuracy. The inventive approximation is carried out in a limited range of values of X that allows you to apply simple approximating function that was easy to do. The Converter includes a block dividing amplifier with adjustable gain and a unit for extracting the square root of the sum of known and unknown square values. Positive effect: used, an approximate function allows you to simplify the Converter, to provide a large dynamic range for the input signals, high-speed, low truncation error (less than 0.17 per cent) and low instrumental error, which does not exceed methodical. 1 Il. The invention relates to computer technology and can be used in information-measuring systems, as well as in various functional converters, when you want to determine the value of sin X with high performance, low accuracy and ease of implementation in the interval C is tan and have low error in conversion of about 0.1% in the interval from 0 to 4, but have poor performance.Known sine inverter, containing shaper rectangular pulses, the differentiation block, the delay unit, managed key and a block of memory.This Converter has a low error value, however, has a low performance.A device for calculation of trigonometric functions containing two out phase-sensitive rectifier and connected in series time-pulse Converter, the pulse shaper, the integrating amplifier and the amplifier-limiter as well as a generator of sinusoidal oscillations.This device has an error due to drift of the integrator, and most importantly has a low performance.Known sine Converter comprising multipliers, adders, reference voltage that determines the scale of the transformation.A device for providing low error conversion uses a fairly complex function approximation, which can be represented as follows:
sin ( /2)X (1.574 X 0,361 X2< / BR>0,21265 X3)/(1-0,2097 X + 0,2097 X2for angles from 0 to /2.In this case, the device which, limited dynamic range due to the presence of second and third degree if the argument and will have quite a lot of instrumental error, because error several nonlinear devices will determine the overall error.Closest to the invention is sine inverter, formed by an amplifier the gain of which varies in a nonlinear law, allowing for changes of the argument from 0 to /4 approximating a function close as desired. The desired non-linear function get when using multiple breakpoints, applying the reference voltage and the diodes in the feedback circuit of the amplifier.The aim of the invention is to improve the accuracy of measurement with ease of implementation and high performance.The essence of the invention lies in the fact that with a limited value of the argument (for example, 0 X /4) approximation can be done with a simple function with high precision, specifying the following approximate equation:
sin X X f (X) for 0 X 0,7854, (1) where X is the value of the argument;
f(x) 1/ f(X) 1.0 when A >(aX)2;
A, A the coefficients are chosen from the condition of minimization poterjami amplifier with adjustable gain, the input and the output of which is connected to the input and output of the Converter, respectively, further comprises a unit for extracting the square root of the sum of known and unknown square values, the input connected to the input of the Converter, and the output with the control input of the amplifier with adjustable gain.The drawing shows a structural diagram of trigonometric Converter.Trigonometric Converter comprises an amplifier 1 with an adjustable ratio transmission and the block 2 to extract the square root of the sum of known and unknown square values.Blocks in the Converter are connected in the following way. The input of the Converter is connected to the inputs of the amplifier 1 with an adjustable ratio transmission unit 2 to extract the square root from the sum of the known and unknown quantities, the yield of the latter is connected to the control input of the control amplifier 1. The output of the amplifier 1 with an adjustable ratio transmission connected to the output of the trigonometric Converter.The Converter operates as follows.Input voltage Uxcorresponding to the value of the argument X, postopia what we known and unknown square units receive the voltage U2, which depends on the voltage Ux. This voltage U2 controls the gain of the controlled amplifier 1. Unit 2 is composed of a reference voltage IEP. Is the IEP in unit 2 is chosen of such size that when the control voltage U2 IEP gain controlled amplifier 1 is equal to the unit. The voltage U2 at the output of block 2 to extract the square root of the sum of known and unknown square values can be represented in the following form:
U2 U2 IEP if (aUx IEP, (2) where the coefficient a is chosen in accordance with a minimum value of error executing equality (1).This voltage U2 is fed to the control input of the amplifier 1 with an adjustable gear ratio. The transmission coefficient of this controlled amplifier 1 is inversely proportional to the control voltage U2, which is changed in accordance with the expression (2), so the output voltage U1 can be written as follows:
U1 U u x f(x), (3) where f(x) 1/f(Ux) or f(x) 1/
Consequently, the received expression in accordance with (1).U1 Uo= sinx xf(x) x1/ f(x)<1,<BR> A, A coefficients chosen from the condition of minimization of the approximation error.Error approximat based on 0 X 0,7854 will correspond to the error in the determination of the values of sine, changing from q 0 to q 0,34% of All errors in this case have a positive value, therefore, reducing all values in the device 0.17% received methodological error in conversion, equal to the value q/2, i.e. 0.17% of
The ease of implementation provides a small amount of instrumental error, which will not exceed the truncation error, if the error of the controlled amplifier 1 is not more than 0.17% of it is easy to perform, since the gain of the controlled amplifier should be changed only in the range from 1.0 to 1.12. Requirements error block 2 to extract the square root of the sum of known and unknown square value is easy to perform, since it is approximately 0.17% need to provide a small range of variation of the argument (and Ux < 0.5 IEP) that for this implementation is easy.Another advantage of the proposed Converter is the ability to change the input signals in a large dynamic range, which is achieved by use of the device with the transfer ratio is not greater than one. When implementing more complex functions to keep the gear ratio is not greater than one difficult.The device is implemented with the aid of the change of resistance of the feedback resistor or using a controlled voltage divider. Unit 2 to extract the square root of the sum of known and unknown square values are also implemented using known links. Trigonometric Converter containing unit, the first input of which is connected to the input of the Converter, and the output of the inverter output, characterized in that it introduced the unit to extract the square root of the sum of known and unknown square values, the input connected to the input of the Converter, and the output from the second input unit.
FIELD: computer engineering; automation, data processing and measurement technology.
SUBSTANCE: proposed converter has two registers, NOT gate, angle-code-to-sine/cosine-code functional conversion unit, two digital-to-analog converters, reference voltage supply, pulse generator, counter, two capacitors, subtracting amplifier, two modulators, threshold unit, two selector switches, two buffer followers, threshold voltage supply, comparison circuit, D flip-flop, and reference code shaper; all these components enable functional control of converter during recording pulse time and supply of signal indicating normal or abnormal operation of converter to user thereby essentially raising its self-control ability and yielding profound and reliable information.
EFFECT: enhanced comprehensiveness of control and reliability of converter output data.
1 cl, 2 dwg
FIELD: computer engineering, in particular, functional transformers of angle code to sine-cosine voltages, possible use in data processing systems.
SUBSTANCE: device contains block for functional transformation of angle code to code of sine and cosine, generator of impulse pack, NOT element, registers, support voltage source, digital-analog converter, switch, capacitors, buffer repeaters, modulators, threshold block.
EFFECT: increased precision of transformation.
2 cl, 2 dwg
FIELD: physics, computer engineering.
SUBSTANCE: invention relates to computer engineering, specifically special-purpose computers. The technical result is achieved by a device for calculating trigonometric functions, which comprises sine and cosine registers, increment registers of the same values, two converters for converting direct code into complementary code, connected, besides by connections between said units, with a clock pulse generator, a memory unit and an argument counter.
EFFECT: method of removing limitations on an argument of calculated functions in the range from 0 to + when calculating trigonometric functions.