SU1320652A1 - Shaft position pickup - Google Patents

Abstract

The invention relates to a measurement technique and can be used as a sensor for the angular position of a shaft of digital follow-up systems. The sensor contains a pulse generator 1, a counter 2, a shaper 3 of the reference signals, a phase shifter 4, a zero-body 5, two registers 6, 7. A register 8, an adder 9, a digital comparator 10, a sensor 11 of a code element are entered into it to increase noise immunity. 12 delays, element 13 I. Before writing to output register 6, the information is analyzed by comparing the difference between the codes at the (i-1) and iM phase intervals with a certain constant number. If the difference is larger than this number, then the information is considered false and is not written to output register 6, which eliminates bursts of code values from the sensor output information caused by impulse noise. 1 il. U5 oo yo o) sd yu

Description

The invention relates to a measurement technique and can be used as a sensor for the angular position of a shaft of digital follow-up systems.

1, the spruce of the invention is improving noise immunity by determining and excluding from the output the information generated due to the effect of impulse noise.

The drawing shows a block diagram of a shaft position sensor.

The sensor contains a pulse generator 1, a counter 2, a driver 3 of the reference signals, a phase shifter 4, a zero-body 5, registers 6-8, an adder 9, a digital comparator 10, a code sensor 11, a delay element 12 and an element 13.

The output of the pulse generator 1 is connected to the input of the counter 2, the high discharge output of the counter 2 is connected via a serially connected driver 3 of the reference signals and the phase shifter 4 is connected to the zero-organ 5, the output of the zero-organ 5 is connected to the register inputs 7 and 8, and also connected via the delay element 12 with the first input element And 13, the output of which is connected to the synchronous input of the first register b, the code from the output of the counter 2 simultaneously enters the registers 6 and 7 and the output of the register 7 is connected to the input of the register 8 and to the second input of the adder 9, the output I-lurrpa 8 is connected to the first input of the adder 9, the output of which is connected to the first input of the digital comparator GO, the second input of the digital comparator 10 is connected to the sensor 11 of the code, and the output to the second input of the And 13 element.

The sensor works as follows.

Generator 1 generates stable frequency pulses supplied to counter 2, the highest bit of which is connected to the reference signal shaper 3, which generates two quadrature sinusoidal voltages supplied to the primary windings of the phase shifter 4. The output voltage of the phase shifter 4 is shifted relative to the reference voltage at the angle of rotation of its shaft, the moment of transition of the output voltage through zero is fixed by the zero-body 5. On the leading edge of the output voltage of the zero-body 5, a record is made to and corner registers 6-8, wherein the register 6, information is recorded only if there is a resolution of the digital comparator 10, otherwise the register 6 still remains information. The prohibition of writing the angle code in the register 6 is formed by the fulfillment of the condition.

I K, -K, -1 I L K, -,

where k ,, k, -1 is the value of the angle codes on the i-th and (i-1) -th sampling intervals;

LC; -maximum possible difference of codes in the sampling interval at the maximum speed of rotation of the shaft.

The code difference calculation is performed by adder 9, the first input of which receives code K, i with reg, ister 8, and the second input receives code K, from register 7. The difference of the codes is compared with a constant DC value;

and if condition (1) is fulfilled, the writing of the Ki code to the register 6 is prohibited, if not, the recording signal from the null organ 5, previously delayed by the delay element 12 during the execution of the specified operations, passes through the And 13 element to the synchronous input 6 in which the code of the angle K is written,;.

If the position sensor receives power from an industrial network or is powered from an autonomous source that simultaneously feeds any powerful receivers with pulsed power consumption, a pulse disturbance penetrates the capacitances of the transformers in the sensor circuit, which manifests itself as a high-frequency pulse superimposed on the output the voltage of the phase shifter and at high resolution of the sensor causes false positives of the null organ. 5. At the sensor output, this manifests itself in the form of noise, short-term abrupt changes in the readings.

In digital tracking systems, the speed of rotation of the shaft, as a rule, is limited; therefore, the rate of change of the angle in the sampling interval is known and is possible at the maximum:

35АКмакс - 7

(2)

where yumax is the maximum speed of rotation of the shaft, rad / s;

Rm is the sampling frequency (fr -

the frequency of the master oscillator, n is the size of the counter 2).

The change of the angle during the sampling period cannot exceed the value determined by expression (2). Therefore, 5 if LCmax dK /, then the information is reliable, otherwise the information is considered false and is not recorded in register 6.

Claims (1)

Invention Formula 0 Shaft position sensor containing a pulse generator, a counter, a driver of reference signals, a phase shifter, a zero-body, two registers, the output of a pulse generator is connected to the counter input, the output of the group of outputs through the driver of reference signals and the phase shifter is connected to the zero-input, the group of outputs of the counter is connected to the information inputs of the first register. the output of which is the output of a shaft position sensor, characterized in that, in order to improve noise immunity, a third register, an adder, a code sensor, a digital comparator, a delay element, an AND element, whose output is connected to the first register synchronous input, a group of counter outputs are entered into it connected to the information inputs of the second register, the group of outputs of which is connected to the information inputs of the third register and the first group of inputs of the adder, the outputs of which are connected to the first group of inputs of the digital comparator, the output of which is connected to the first input of the element I, the output of the zero-body is connected to the synchronous inputs of the second and third registers and through the delay element to the second input of the element And, the outputs of the third register are connected to the second group of inputs of the adder, the outputs of the sensor code is connected to the second group of inputs of the digital comparator.