United States Patent 6,240,435

Sibeykin May 29, 2001

Method and device of determination of an input signal which changes in time

Abstract

A method of determination an input signal changed in time and its integral value has the steps of integrating an input signal to a given value of an integration result for a final point, and performing calculations also for a plurality of intermediate points.

 

Inventors: Sibeykin; Sergei (Brooklyn, NY)

Appl. No.: 084340

Filed: May 26, 1998

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Current U.S. Class: 708/444 ; 702/142

Current International Class: G05B 23/02 (20060101)

Field of Search: 708/200,433,444,290 702/141,142,144,146,147

 

 

References Cited

 

U.S. Patent Documents

4030038 June 1977 Daniel et al.

5031134 July 1991 Kaplan et al.

5490067 February 1996 Teguri et al.

5790442 August 1998 Ninomiya et al.

 

 

Primary Examiner: Ngo; Chuong Dinh
Attorney, Agent or Firm: Zborovsky; I.

 

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Claims

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What is claimed is:

1. A device for determination an input signal which changes in time and at its integral value containing n reference signals, comprising a multi-position switch through which the reference signals and the input signal are supplied to a convertor analog-frequency, a key, a counter; a unit of registration of reference signals; a memory unit; an arithmetic-logical unit; a register of expected integral value of the input signal; a digital comparator; arranged so that outputs of the counter are connected to inputs of the memory unit and unit of registration of the reference signals, outputs of the memory unit and the unit of registration of reference signals are connected to inputs of the arithmetic logical unit, digital outputs of the arithmetic logical units are connected with input of the memory block and the register of expected integral value of input signal, control outputs of the arithmetic logical unit are connected with control inputs of the key and multi-position switch, inputs of the digital comparator are connected to outputs of the counter and the register of the expected integral value of input signal, in which the arithmetic logical unit write a code equal to a sum of products of every time interval and frequency of the convertor analog-frequency, corresponding to the reference signal wherein the every time interval are obtained from an n equation system in accordance with power m in which a left part of each equation in a sum of products of the time interval T.sub.1 by the corresponding reference signal in the power m and a right side of each equation is a product of time of determination of the input signal by its initial moment of the power m, when, wherein m changes from one equation to another equation in a sequence 0, 1, . . . n-1 and the digital comparator fixes reaching by an integral value or the input signal of a value which is equal to a sum of the products of the time interval by the corresponding value of the reference signal.

2. A method of determination an input signal changed in time and its integrated value, comprising the steps of integrating to the given magnitude n reference signals which have a same nature as the input signal, the times interval of the reference signals are determined from conditions of equality the product time of determination of an input signal by its initial moment power m=0,1 . . . n-1 and the sum of products the time interval of a every reference signal by its value in a power m; integrating an actual input signal over time; and determining the reaching of a given magnitude by an integrated value of the input signal by coincidence of a result of the integrating of n reference signals and a result of the integrating of the actual input signal.

 

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Description

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BACKGROUND OF THE INVENTION

Sensors convert nonelectrical physical or chemical quantities into electrical signals. The behavior of semiconductor sensor devices is modeled, under a series of assumptions, by a system of nonlinear partial differential equations and associated boundary and input value conditions. For such sensors, it is essential to solve numerically at least some of the equations in order to obtain a meaningful result describing environmental conditions encountered by the sensor. Mechanical sensors also suffer from some of the same issues relating to nonlinearity and associated boundary and initial value considerations.

When the desired result is determined by the integration of sensor output over time, errors of bias scale, and nonlinearity occur. Mathematical algorithms are used to improve the accuracy of the result by correcting for such errors of bias, scale and nonlinearity.

The present invention relates to methods and devices of determination of an input signal which changes in time as well as of its integral value.

Methods are known of the above mentioned general type and disclosed for example in Inventor's Certificates of the USSR 1,453,418 and 1,541,635. In accordance with the method and device disclosed in these references, integration is performed to a given value of the integration result. This objective is presented for example in inertia systems of targeting, for turning off an engine when a rocket reaches a desired speed Vr. The input signal in this case is an acceleration which is measured by accelerometer, and its inaccuracies are a main source of error of the system as a whole. The device includes a convertor 1 for a frequency of pulse sequence, a frequency multiplier 2, an integrator or pulse counter 3, a source of reference signals 4, keys 5 and a control device 7. A code corresponding to a desired value of speed is introduced into the pulse counter by integration of reference signals (accelerations) during a time corresponding time interval. The values of the reference signals can be obtained by turning a sensitivity axis of the accelerometer relative to a local vertical. Then, during measurements of the input signal which is the acceleration during a flight, an inverse integration is performed. In other words, the pulses from the convertor, multiplied many times by the frequency multiplier are deducted in the counter from the code obtained during the time of direct integration when the counter was operating for addition of the reference signals. A system of equations was used to determine the reference signals and time intervals. The nature of change of the input signal was approximately known beforehand, and therefore an initial moment of the input signal was calculated. Zeroing of the pulse counter is a signal that the speed reached the desired value. The above described method has a high accuracy. However, it has some disadvantages, namely the fact that the high accuracy is guaranteed in only one point and not along the whole scale of speed changes. This values must be known in order to determine of the location of a rocket. The known method and device are not always technically implementable since it is necessary that one reference signal is greater and the other is smaller than an average value of the input signal. However, the acceleration can reach a few g while on the ground during giving of the reference signals not always there is a standard of acceleration more than 1 g.

SUMMARY OF THE INVENTION

Accordingly, it is an object of present invention to provide a method and device which eliminates the disadvantages of the prior art.

In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention resides, briefly stated, in a method of determination of an input signal changing in time, in which conversions which were performed for a final point in accordance with a known algorithm disclosed in the prior art, is also performed for final point tn for intermediate t1, t2, tk in accordance with a modified algorithm, so that it is possible to use not reference signals which are required by change curve of a changing acceleration, but reference signals which are available or in other words can be less than 1 g. The desired movement parameters are determined during the flight, and therefore a deviation of the acceleration curve from an expected acceleration curve does not reduce the accuracy.

In accordance with another feature of the present invention the device is provided with means for performing the above mentioned conversions for intermediate points as well.

The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS


FIG. 1 is a view showing a device for determination of an input signal which changes in time in accordance with known method;


FIG. 2 shows a linear increase in input signals and an adjustment in the reference signals using the known method;


FIG. 3 graphically shows a changing speed over time where:

curve 1--actual speed

curve 2--reading of speed without correction

curve 3--reading of the speed using the known method, where the reference signals are introduced for the moment in time (tn);

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