SU1597882A1 - Device for linearizing static characteristics of pickups - Google Patents

Abstract

The invention relates to a measurement technique and can be used to convert input information from sensors having a nonlinear characteristic of a monotonically increasing concave view in a given dynamic range. The purpose of the invention is to reduce the time required in preparation for the operation of the device for linearization in the case of replacement of a failed sensor. The goal is achieved by quickly reconfiguring the device by changing the value of the pre-calculated coefficients of the conversion function. The principle of operation of the device is that the output voltage from the sensor acts as a parameter of the exponential voltage generator, which varies according to the measured value according to a logarithmic law. Thereby, a linear relationship between the measured value and the output voltage is achieved. By changing the coefficients of the logarithmic function, it is possible to describe with its help real output monotonically increasing concave-type characteristics of the sensors.

Description

315

FIG. 3 — implementation of individual units of the device.

FIG. 3 the following designations are given: a - linear signal generator; b - logical switch; in - unit registration result; g - block assignment factors; d - exponential voltage generator.

The device for linearizing the static characteristics of the sensors includes a linear signal generator 1, a comparator 2, a logic switch 3, a reversible counter 4, a generator of 5 clock pulses, a coefficient setting unit 6, an exponential voltage generator 7, a recording unit 8.

FIG. 2 items marked:

9 - nonlinear input characteristic and, given in the range of Co, X And;

10 - output signal of the generator 1 line signal; 11 is an output signal of an exponential voltage generator 7; 12 - output characteristics of the device for linearization.

Line signal generator 1 can be implemented as an integrator

. on the basis of the operational amplifier 13, the variable resistor 14 and the capacitor 15 (FIG. 3a). Logic switch 3 can be obtained by a combination of logical elements And T6 and 17 and NOT 18 (Fig. 36). The result recording unit 8 can be executed in the form of serially connected analog-to-digital converter (ADC) 19 and register 20 (Fig. Sv). The coefficient setting unit 6 can be made in the form of a series-connected adjustable voltage source 22 (IRN) and a variable resistor 21 (Fig. 3g). The exponential voltage generator 7 (Fig. A) can be made in the form of a parallel-connected electronic switch 23 and a capacitor 24.

The operation of the device is based on the following theoretical calculations. The nonlinear characteristic of a monotonically increasing concave type sensor in a given dynamic range (FIG. 2, curve 9) can be identified by the type equation

tt d 1 p--

 n in - X

(one)

where a and b are coefficients;

X is an input parameter.

Thus, j function (1) dl. The chosen class of non-validity can be selected as a dp identification structure. Since the coefficients in (1) are not specifically indicated, then function (1) can identify the characteristic of any sensor that has a monotonically increasing concave appearance.

To linearize the sensor characteristic described by function (1), it is possible, using for this purpose a function generator with the function of conversion:

UN

V P (1 Q

), (2)

where P and Q are coefficients.

Perform the substitution (1) and obtain the linear dependence V of the measured parameter X: А. at

V P (1 (2), from iz a -6)

to-x (3)

five

0

five

0

five

0

five

provided A Q.

Since the coefficients P and Q are not specified in (2) specifically, using the structure (2), the characteristic of any sensor described by (1) can be linearized.

To implement the function (2), an exponential voltage generator 7 was created in the linearization device, with the transformation function

--tlQ. Uet (X7 P- (1 - e), (4)

where P and Q are coefficients;

t - time input parameter.

The device works as follows.

Before starting work, the parameters of the generator 7 of the exponential voltage are set using the block 6 for setting the coefficients; the maximum value of the output voltage and its rate of rise, preliminarily calculated as coefficients P and Q, as well as the slope of the characteristic of the generator 1 of the linear signal using a resistor 14. It should be taken into account that in a given dynamic range O, Ugj, wkh m "ks / at the input of the device, the voltage UK is established, corresponding to the measured parameter X, (Fig. 2, curve 9). After starting the device from the output of the generator 1 line signal to the second input

Nl

FIG. g

t

TSN / groin output7

Uhi

Fig.Z

nineteen

UPR

one

20

Out

Vh.

Claims (1)

The formula of the invention of the signal reaches the input voltage level U _H , for a time t, = t _₽ N, where t ₀ is the calibrated pulse duration of the generator of 5 clock pulses; N is the number of pulses counted by the counter 4, i.e. time t will be counted and recorded in counter 4. If U _Hl = =, then the output signal of comparator 2 will switch from high to low. As a result of this 20, the output of the clock generator 5 is connected via a logic switch 3 to the subtracting input of the reversible counter 4 and the exponential voltage generator 7 starts. In this case, the reverse counter 4 starts the countdown, i.e. from to 0. During the time from t, to 0, the output voltage of the generator 7 of the exponential voltage βθ (Fig. 2, curve 11) will increase to the level U eux 7 = P · (1 “e). The voltage value U _6MX7 is equal to the value of the linear signal corresponding to the parameter X _p (Fig. 2, line 12). The voltage is converted into digital form and recorded in block 8 registration by the signal the End of the bill coming from the output A device for linearizing the statistical characteristics of sensors, containing a clock pulse generator, an exponential voltage generator, a comparator, characterized in that, in order to reduce time spent on preparing the device for operation, a coefficient setting unit, a reversible counter, a logical switch, a block are introduced into it registration and a linear signal generator, the input of which is connected to the potential output of the coefficient setting unit, and the output - to the first input of the comparator, the second input of which is an input the device’s house, and the output is connected to the control input of the logical switch and the control input of the exponential voltage generator, the information input of which is connected to the output of the coefficient setting unit, and the output is connected to the first input of the registration unit, the output of which is the output of the device, and the control input is connected to the output of the reverse counter, summing and subtracting the inputs of which are connected respectively to the first and second outputs of the logical switch, the input of which is connected to the output of the gene clock pulse generator. FIG. 1 I Fig j