SU506893A1 - Angle Code Transducer - Google Patents

Description

The scrap 5, whose angular position is measured, is rigidly connected to the photoelectric reading device 6 and the light source 7. This photoelectric pair is intended to read the reference bar 4. The fixed photoelectric pair consisting of the reading device 8 and the light source 9 is zero by the authority giving the signal to start counting, and reads the reference bar 4. The stationary reader 10 with the light source 11 is designed to read the strokes of the track 3. The account control device 12 consists of a selector 13 a pulse s and counter 14 number of reference strokes. The pulse selector 13 serves to pass the pulses from the controlled filling generator 15 to the electronic counting device 16, more precisely to its divider 17. The input of the counter 14 is connected to the output of the reading device 6, the output of the counter 14 is connected to the reset circuits of the divider 17, the counter 18 is younger The ports of the measured angle and connected to it through a two-input element OR 19 counters are 20 high-order bits. The first control input of the selector 13 is connected to a device for eliminating uncertainty of the result 21, in particular with the output of the controlled a-unit 22 shift of the counting account, whose input is connected to the reader 8. The second control input of the selector 13 is connected to the output of the reader 6. The output of the block 22 is also connected to one of the inputs of the two-input element “AND 23,: the second input of which is connected to the output of the reading device 6. The output of the element“ AND 23 is connected to the input of the trigger 24 (counting), from one arm of which The control unit 22, and on the other - the generator 25, the output of which is connected to one of the inputs of the two-input element OR 19. The device 26 of the phase locked loop controlled, the generator 15 includes a filter 27, a frequency divider 28 and a phase detector 29. One from the inputs of the phase detector 29 is connected to the output of the frequency divider 28, the input of which is connected to the output of the controlled generator 15. The other input of the phase detector 29 is connected to the output of the fixed-casting device 10. The output of the phase detector 29 is connected through a filter 27 input of the controlled oscillator 15.

The frequency of the oscillator 15 is selected based on the required discreteness of the reference, the angular velocity of rotation of the code disk 1, the density of the application of strokes on the track 3.

When the number of grooves in track 3 is equal to k and the speed of rotation of the disk n (rev / s), the frequency of the electric pulses f coming from the output of the reader 10 is determined from the expression

.n (1)

The frequency of the generator 15 is determined by the expression

h - mf,

(2)

where the number t characterizes the discreteness of reference.

The coefficient of the frequency divider 28 is numerically equal to m.

The time constant of the filter 27 is selected depending on the quality of manufacture of the code disk, its uneven rotation with a given counting resolution, the rotation speed and the density of the strokes applied to the track 3. The quality of the angle measure refers to the quality of the strokes themselves and the accuracy of their application.

The described device operates as follows.

When the code disk 1 rotates, the pulses from the reading device 8 enter through the control unit 22 to the control input of the selector 13, open the selector, allowing the filling pulses to pass from the generator 15 to the counting device 16. The pulses from the movable reading device 6 close the selector 13.

Thus, the selector 13 opens and closes once per turn of the disk 1, ensuring that a number of filling pulses pass through the counting device 16 proportional to the value characterizing the angular position of the input shaft 5. Divider 17 divides the number of filling pulses passed through the selector 13, for a predetermined number of counts (number of revolutions p of disc 1). During the time corresponding to p disc 1 revolutions, the number of filling pulses transmitted through the selector 13 and divider 17 to counters 18 and 20 is proportional to the value characterizing the angular position

the input shaft 5. In time, the corresponding, p disc revolutions 1, the counter 14 overflows and outputs a reset pulse to the counters 18 and 20 and the divider 17, and also carries out the transfer of the result, for example, to a digital indicator.

The counting device 16 assumes the presence of various delays (reset, transfer) for correct processing of the result. The device 21 operates as follows.

With the simultaneous arrival of pulses from block 22 and from device 6 to both inputs of the element “I 23, a pulse arises at its output, which with its leading front overturns the counting trigger 24. The signal from one arm of this trigger acts on block 22, which delays the opening of the selector 13 for a time interval corresponding to, for example, a travel time with /

pulses read from track 3 by reading device 10. The signal from the second arm of trigger 24 acts on generator 25, which gives q pulses. These pulses go through the element “OR 19 to the counter

20 and are added to the corresponding bits once during the revolutions of the disk p 1, which is achieved by applying a control signal from counter 14 to generator 25. With repeated coincidence of signals opening and closing the selector 13, the trigger 24 is tilted again, delay counting is removed, the output of the pulse generator 25 is closed.

The device 26 operates as a conventional phase locked loop device. The divider 28 ensures that the frequencies of the signals at both inputs of the phase detector 29 are equal. The reference signal from the reader 10 is fed to the phase detector 29 continuously, thus maintaining a constant frequency ratio / f / c accurate to the phase, i.e. constant counting resolution .

The track of the 3 stroke code disk is only necessary for the operation of the device 26 phase autolod frequency.

Claims (1)

Invention Formula Angle-code converter containing a rotating code disk, a movable reader rigidly connected to input shaft and connected to the input of the control unit of the counter, which is connected to the electronic counting device, a fixed reader, nullOffraiH and a filling generator, connected to the account control device, characterized in that, in order to improve the accuracy of the converter, a phase detector is inserted into it, frequency divider, filter, pulse generator, trigger, the element "And and the shift block of the beginning of the account, the first input of which is connected to the zero-body, the second input is connected to the trigger output, and the output is connected to the control device by the account and to one of the inputs of the element "And, the other input of which is connected to the stationary reading device, the output of the element" And through the trigger is connected to the first input of the pulse generator, the second input of which is connected to the account control device, and the output is connected to the electronic counting device, wherein the fixed reading device is connected via a phase-connected phase detector and a filter to a filling generator, which is connected to a phase detector through a frequency divider. one