SU491974A1 - Method for cyclic conversion of shaft rotation angle to code - Google Patents

Description

one

The invention relates to the field of automation and computing, in particular to the conversion and encoding of information.

A known method of cyclic transformation of the shaft rotation angle using a sine-cosine rotating transformer (CCT) is based on the formation of time intervals at the amplitudes of the sine, cosine (reference) supply voltages and output voltages of the sinus, cosine rotor windings, equal to zero, and filling time intervals by pulses of exemplary frequency.

In this method, the conversion cycle time cannot be made shorter than the period of the supply (reference) voltage, since the cycle includes the time between the start of the conversion pulse and the passage of the reference voltage through zero and the time before the output voltage passes through the zero.

The aim of the invention is to increase the speed of the method (reducing the conversion time).

The goal is achieved by forming a time interval in each conversion cycle between the sinus or cosine reference voltage closest to the beginning of the cycle and the sinus or cosine output voltage following it, depending on the combination of the reference and output voltages and the direction of their zero crossing. form two high-order code.

FIG. 1 is a block diagram of a converter for implementing the inventive method; in fig. 2 - time interval formation diagrams.

The stator windings 1 and 2 of SCPT 3 are connected to a two-phase power source 4.

A sinus supply voltage is applied to the input of the null organ 5, at the first output of which a pulse is formed (Ub when the voltage goes from negative to positive values, at the second output

impulse Us, when moving from positive to negative values (see Fig. 2). The cosine voltage supply is applied to the input of the zero-organ 6, at the first output of which the LJe pulse is emitted, at the transition from

positive values to negative, at the second output a pulse Ue is released, when going from negative values to positive ones. The voltages from the sine and cosine rotor windings 7 and 8 of the rotating transformer 3, respectively, are fed to the inputs of the zero-bodies 9 and 10. At the first output of the zero-body 9, an Id pulse is emitted, when the output sinusoid passes from negative to positive values, at the second output - impulse Ug, when moving from

positive values to negative. At the first and second outputs of block 10, the pulses t / iOi and L / 10 are separated from the output cosine.

The impulses (passing through zero) Us,, 5, Us, Ue, and Usi, Ua, f / iOi, by, through gates II -18 are fed to the number memorizing unit 19, which represents the set of the flip-flops set in “On the impulse of the beginning of the transformation (NP). In the conversion cycle, the beginning of which is given by the NP pulse, the kopets (KP), one of the pulses u9 ,, t / 9 ,, f / 10 ,, Uio., Remembers only two numbers, one from the reference voltages, and the second from the output voltages .

The shaper 20 of the two most significant bits, which is a logical block, in combination with the state of the triggers of block 19, generates codes according to the table. 1. Angle values are given in brackets.

Tables a

But remove compilation table. Since the time intervals between one of the pulses

Us ,, Us ,, and in ,, and 6 ,, and other C / 9 ,, f / 9 ,, and 10 ,,

Ulo can not express the angle more than l / 2, large angles should be obtained by correcting the higher bits. Suppose, after the impulse of the NP, the impulse Us appears first (after the first impulses Ua ,, Ug ,, Uw, Uio, is excluded from the circuit), and the second - Us ,. As seen from FIG. 2, the time interval between Us, and U9, directly expresses the angle of rotation of the shaft of the phase shifter. This rotation angle is less than / 2.

In the higher bits there should be a code 00, which is formed during the formation of the time intervals between the pulses Us, and Us, UG, and Uio, Ue, and C / V ,.

When, for example, the first pulse appears and in, and the second and 9, the convertible angle corresponds to the code from the time interval conversion Ue, -Us, with the addition of the code corresponding to the angle, i.e., the higher bits must be 10 It is easy to get codes in the higher bits and in other combinations of numbers (see Fig. 2).

Consider the formation of time intervals and their conversion into the code in FIG. 1. The impulse NP sets in "About the memory unit 19 and the counter 21 and through the delay line 22 - the trigger 23. At the same time, the resolving potential appears at the gates 11, 12, 13, 14: and 24. After that the first of the pulses, corresponding to the numbers Us ,, Us ,, Ue ,, Ug and goes through the circuit OR 25, valve 24, and switches the triggers 26 and 23. From the trigger 26, a permit is applied to the valves 15-18 and the gate 27, which transmits pulses of the exemplary frequency of the generator 28 to the input of the counter 21. The resolving potential at the output of the trigger 26 is stored until the first of the pulses Ug ,, UQ, Uio ,, LlOj through valves 15-18 and the scheme OR 29.

This pulse triggers trigger 26 and is considered the end of a transform (CP). The shaper 20 and the counter 21 give the code corresponding to the angle of rotation of the shaft of the phase shifter.

In this method, the conversion cycle time is the sum of the waiting time of the reference pulse, which does not exceed 1/4 of the period of the supply voltage, and the time of appearance of the pulse from the output voltages of the SCRT, which also does not exceed 1/4 of the period of the supply voltage.

The speed of the method is two times higher compared with the known.

Claims (1)

Invention Formula A method of cyclically converting the angle of rotation of the shaft into a code based on the formation of stresses proportional to the sine and cosine of the angle with subsequent transformations to time intervals at values of the crush and cosine reference and output stresses equal to the bullet, and filling the time intervals with pulses of the reference frequency, characterized in that, in order to increase the speed of the method, in each cycle of time conversion, an interval is formed between the sinus or Kociniy onorny tension that is closest to the beginning of the cycle Then, following a sinus or cosine output voltage, and depending on the combination of the reference and output voltages and the direction of their crossing through zero, two leading code bits are formed. tin On Cos bn $ in 8bixCos Btiix.