RU142368U1 - TWO-CHANNEL SHAFT ANGLE CONVERTER TO A TWO-COUNT SKT WITH AN ARBITRARY NUMBER OF ELECTRIC REDUCTION - Google Patents

Abstract

A two-channel converter of the angle of rotation of the shaft into a code of a two-counted sine-cosine transformer with an arbitrary number of electric reduction, characterized in that to increase the accuracy of the measurement, a two-channel angle sensor with any existing number of electric reduction is used, containing a reference voltage generator, the outputs of which are connected to the analog-to-digital inputs the angle converter of the first and second channel, the field windings of coarse and accurate readings of the angle sensor, the outputs of which are connected to the input I will give a large-scale amplifier of the first and second channels, respectively, whose outputs are connected to the inputs of an analog-to-digital converter of the angle of the first and second channels, respectively, to reduce the two channels and calculate the final code of the angle of rotation of the shaft, a microcontroller is used, the input ports of which send data lines of the output code of the analog- digital angle converter of the first and second channel.

Description

The utility model relates to measuring technique and can be used in precision systems for measuring the angle based on two-count inductive sensors of sine-cosine transformers (SKT) of coarse and accurate channels with an arbitrary number of electric reduction.

Known single-channel converters of the sensor signals into a digital code [Patent No. 2286012 IPC H03M 1/64 of the Russian Federation "Converter shaft rotation angle into code"; Chernyshev D.A.], also converters implemented in the form of microcircuits, for example, AD2S83, AD2S1210, etc.

Two-channel angle converters of double-counted SKTs are also known, the number of rough reduction of which does not exceed 1 [Circuit design of digital displacement transducers: Reference manual / V.G. Domrachev, V.R. Matveevsky, Yu.S. Smirnov. - M .: Energo-atomoizdat, 1987. - 392 p.: Ill.]. The disadvantage of such converters is the inability to use the angle sensor with the number of electrical reduction of the coarse reference greater than one.

To increase accuracy and resolution in the technique, angle sensors are also used with a number of electrical reduction of coarse readings other than 1 (for example, 3:16, 3:32, 3:64, etc.). Each channel of such a sensor does not have an unambiguous relationship between its signals and the angular position of the shaft φ, therefore, to determine the latter, it is necessary to use a special calculation algorithm.

The technical result of this utility model is to increase the accuracy of converting the angle of rotation of the shaft into a code.

A device that implements angular-digital angle conversion is shown in FIG. 1. It contains a dual-count SKT sensor with coarse and accurate channels 1, 2, scale amplifiers 3, 5, a reference voltage generator 4, analog-to-digital angle converters 6, 7, and a microcontroller 8, which calculates the angular position code of the sensor shaft Nφ.

A two-channel converter of the angle of rotation of the shaft into a two-counted sine-cosine transformer code with an arbitrary number of electric reduction, containing a reference voltage generator 4, the outputs of which are connected to the inputs of the analog-to-digital converter of the corner of the first and second channel 6, 7, the excitation windings of rough and accurate readings of the angle sensor 1, 2, the outputs of which are connected to the inputs of a large-scale amplifier of the first and second channels 3, 5, respectively, whose outputs are connected to the inputs of an analog-to-digital converter SFA first and second channel 6, 7 respectively, for the information of two channels, and calculating the final code of the shaft rotation angle used by the microcontroller 8 to the input ports of which are supplied the output code of the data bus D-converter of the angle of the first and second channel 6, 7.

The device operates as follows.

For the angle sensor to work on its field windings of coarse and fine channels 1, 2, an equal voltage is supplied from the output of the reference voltage generator 4

U _OD = U ₀ Sinω ₀ t,

where ω ₀ is the excitation frequency of the sensor;

U ₀ is the amplitude of the reference voltage.

The rough and accurate channels of the angle sensor 1, 2 produce modulated sinusoidal signals, U ₁ , U ₂ , U ₃ , U ₄ , which are brought to the required amplitude using scale amplifiers 3, 5 U ₅ , U ₆ , U ₇ , U ₈ .

Further, the analog signals are respectively fed to analog-to-digital angle converters 6, 7, converting them into digital parallel codes of the angles of coarse N _Г and exact N _T channels. The synchronization of the work of analog-to-digital converters of the angle 6, 7 and two channels of the angle sensor 1, 2 occurs according to the signal U _op . Digital codes N _G and N _T come to the microcontroller 8, which, in turn, by a special algorithm (Fig. 2) calculates the code of the angle of rotation Nφ of the shaft. To change the number of electric reduction, the microcontroller can be reprogrammed using programmer 9.

It is proposed to calculate the angular position of the shaft φ using the formula

where φ _G , φ _T - the angle of the rough and accurate reference;

k _G , k _T is the number of electrical reduction of the coarse and accurate reading of the sensor;

Δφ is the angle of difference between the coarse and fine channels.

The calculation begins by checking the conditions of formula (1) for i and n equal to one. Then it is checked with a sequential increase in n by one to n = k _T. If the condition is not met, then the value of i increases sequentially by unity to i = k _G -1 and the procedure of enumeration n is repeated.

,When the conditions of formula 1 are satisfied, the calculation process stops and the output code is the angular position of the sensor shaft

,

where φ _D0φ is the angle corresponding to the unit of the _{least significant} bit of the shaft rotation angle code.

Graphically, the calculation algorithm is shown in FIG. 2.

According to the algorithm implemented by microcontroller 8, at the first moment of time, the data ports of the microcontroller A, B, C (1) are initialized, which consists in establishing the direction of the ports (ports A and B for data input, port C for output). The next step (2) is to assign the variables φ _D0Г , φ _D0Т , φ _D0φ , Δφ, k _Г , k _{Т to the} values of constant values, where φ _D0Г is the angle corresponding to the _lowest -order unit of the angle code N _{Г of the} rough channel of the angle sensor, φ _D0T is the angle corresponding to the unit of the least significant digit of the code of the angle N _{T of the} exact channel of the angle sensor, φ _D0φ is the angle corresponding to the unit of the lowest digit of the code of the angle Nφ of the shaft rotation, Δφ is the angle of difference between the coarse and exact channels, k _G is the number of electric reduction of the rough channel, k _G is the number electrical reduction of the precise channel. Next, the codes N _G and N _T (3) are read from the data reception ports received from analog-to-digital angle converters 6, 7 and converted (4) into the corresponding values of the coarse φ _G angles and the exact φ _T channels in degrees. Then the counters i and n are reset to zero (5). The next step (6) verifies the truth of the equality of the values of the angles of the coarse and accurate channels, adjusted for the angle of difference between them. If the condition is false, then the increment n (8) occurs, where 0 <n <k _T (7). Upon reaching n = k _T , n is reset and the increment i (10), where 0 <i <k _Г (9). The selection of n and i determines the number of periods n of the exact channel to determine the angle of rotation of the shaft φ. Upon reaching i = k _G , the codes N _G and N _T (3) are returned to reading from the data receiving ports. If condition (6) is true, the variable φ (11) is assigned the value of the angle of the exact channel, taking into account the number of periods n and adjusted for the number of electrical reduction of the exact channel k _T. Then, the found angle of rotation of the shaft φ is converted into the angle code Nφ (12) and output to port C of the microcontroller (13).

The advantage of the angle converter is that the device can use a sensor with any existing number of electrical reduction of the coarse and accurate channels, it is enough to establish the corresponding k _G and k _T.

Claims (1)

A two-channel converter of the angle of rotation of the shaft into a two-counted sine-cosine transformer code with an arbitrary number of electric reduction, characterized in that to increase the measurement accuracy, a two-channel angle sensor with any existing number of electric reduction is used, containing a reference voltage generator, the outputs of which are connected to the analog-digital inputs the angle converter of the first and second channel, the field windings of coarse and accurate readings of the angle sensor, the outputs of which are connected to the input I will give a large-scale amplifier of the first and second channels, respectively, whose outputs are connected to the inputs of an analog-to-digital angle converter of the first and second channel, respectively, to reduce the two channels and calculate the final code of the angle of rotation of the shaft, a microcontroller is used, on the input ports of which the data buses of the output code of the analog- digital angle converter of the first and second channel.

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