SU1765690A1 - Ultrasonic displacement transducer - Google Patents

Description

one

(21) 4839314/28 (22) 14.06.89 (46) 30.09.92. Bul №36

(71) Penza Polytechnic Institute

(72) S. B Demin

(56) USSR Copyright Certificate No. 1024692, cl. G 01 B 7/00, 1983.

USSR Author's Certificate No. 1368628, cl. G 01 B 17/00, 1988. (54) ULTRASOUND DISPLACEMENT CONVERTER

(57) The invention relates to a measurement technique, namely to magnetoacoustic displacement transducers, and can be used in robotic systems and complexes for two-coordinate measurement of the parameters of a linear displacement of an object. The purpose of the invention is to improve the accuracy and reliability of the measurement of displacements. The ultrasonic displacement transducer contains an L-shaped magnetostriction acoustic conduit with fixed centered reading elements mounted on it and movable polarizing magnets that are mechanically connected with the moving object. In the branches of the magnetostrictive acoustic conductor, acoustic waves are excited by current pulses, which propagate from the points of location of the polarizing magnets to the ends of the acoustic conductors. According to the time of propagation of these waves in orthogonally located branches of the sound guide, the coordinates of the moving object 2 are judged.

The invention relates to a measurement technique, namely to magnetoacoustic displacement transducers, and can be used in systems of two-coordinate measurement of the parameters of the kinematic motion of an object,

A known ultrasound transducer includes two reichords, a DC voltage source, a pulsating voltage source, and a recorder.

An ultrasonic displacement transducer, selected as a prototype, which contains a base, a sound duct fixed on the base, the first and second acoustic absorbers installed at the ends of the sound duct, the first and second concentrated reading elements mounted on the sound conductor next to acoustic absorbers, connected to the outputs of the latter, the first and second selective amplifiers read shapers and serially connected pulse generator and write amplifier

The main drawbacks of the known device are the low accuracy and reliability of measuring the two-coordinate movement of an object.

The aim of the invention is to improve the accuracy and reliability of movement measurement.

This is achieved by the fact that in the ultrasonic transducer of displacements, which contains a base, a sound duct fixed on the base, the first and second acoustics O SP O Yu O

scaffoldings installed at the ends of the acoustic ducts, the first and second concentrated reading elements mounted on the acoustic duct next to acoustic absorbers, connected to the outputs of the latter, the first and second selective amplifiers reading shapers and a series-connected pulse shaper and recording amplifier, the first is additionally introduced and the second polarizing magnets mounted on orthogonal branches of the acoustic duct with the possibility of longitudinal movement, the first and second control triggers, error control trigger, first and second measurement generators, first and second, result counters, first and second inverters, first and second elements OR, the acoustic conductor is made of magnetostrictive material and is galvanically connected to the output of the recording amplifier, the outputs of the first and second selective readout driver amplifiers are connected respectively to the synchronous inputs of the first and second control triggers, their outputs are connected to the inputs of the first and second measurement generators and the inputs of first element OR. The output of the latter serves as a query bus, the outputs of the measuring generators are connected respectively to the counting inputs of the first and second counters of the result, their bit outputs serve as the first and second buses of the result. The transfer outputs of the first and second counters through the second element OR are connected to the synchronous input of the error control trigger, zero inputs are combined with the inputs of the first and second inverters and connected to the output of the pulse former, the signal input of the latter serves as a start bus, and the control input serves as a control bus and connected to the zero inputs of the first and second control triggers and the error control trigger, the single inputs of all the triggers are combined and connected to the output of the first inverter, the error control trigger output luzhit bus control error output of the second inverter - a synchronization bus, and polarizing magnets designed .dl kinematic compound of the moving object.

FIG. 1 is a block diagram of an ultrasonic transducer; FIG. 2 shows the main timing diagrams for his work.

The ultrasonic displacement transducer (figure 1), contains a two-coordinate primary magnetostriction

displacement transducer (DMPP), consisting of a base 1, an L-shaped sound wire 2 from a magnetostrictive material, two acoustic absorbers

5 3.4, movable polarizing magnets 5,6, fixed lumped elements 7,8, readout and coordinate driving elements 9,10 with sighting element 11, recording amplifier 12 and two

0 selective drive amplifiers 13,14 readings and a secondary converter consisting of a driver of 15 pulses, two control triggers 16,17 and an error control trigger 18, two measuring generators 19,20 and counters 21,22 of the result, the first inverter 23, two elements OR 24.25, the second inverter 26, as well as the control bus 27, the query bus 28, the start bus 29, the synchronization bus 30, the first and second result tires 31.32 and the error control bus 33,

On the basis of the DMPP, a G-type magnetostrictive duct 2 with a bending angle of 90 ° is fixed, enclosed in acoustic absorbers 3,4 and electrically connected to the recording circuit of the recording amplifier 12. Polarizing magnets 5,6 are fixed on its orthogonal branches, made with the possibility of displacement, which are kinematically connected to the object through the coordinate driving elements 9,10 and the sighting element 11.

Near acoustic absorbers 3,4 on the branches of the acoustic duct. 2, fixedly fixed, 5 centered readout elements are fastened, connected to the inputs of the first and second selective shaping amplifiers 13,14 readings. Their outputs are connected to the synchronous inputs of the first and second triggers 16, 17 of the control of the secondary converter, which in turn are connected to the inputs of the first and second measurement generators 19, 20 of the first element 24 OR, respectively.

5 The outputs of the generators 19,20 are connected to the counting inputs of the first and second counters 21,22 result. Their bit outputs are connected respectively to the first and second tires 31.32 results, and

0 transfer outputs through the second element 25 OR connected to the synchronous input of the trigger 18 control error. Its output is connected to the error control bus 33, and the output of the first element 24 OR is connected to the bus 28

5 query. The zero inputs of the trigger 16,17,18 are combined, connected to one input of the driver 15 pulses and connected to the control bus 27. The signal input of the driver 15 pulses connected to

bus 29 run, and the output is connected to the inputs of the amplifier 12 recording, the first and second inverters 23,26 and zero inputs of counters 21,22 result. The output of the second inverter 26 is connected to the synchronization bus 30, and the output of the first inverter 23 is connected to the single inputs of the trigger 16,17,18.

Ultrasonic displacement transducer works as follows.

In the initial state, a control inhibiting signal (Fig. 1) is set on the control bus 27. In this mode, its launch is not possible. Conversion of the converter to the operation mode is carried out when the Resolution signal is applied (Fig. 2a) via the control bus 27. The shaper of 1pulses and triggers 16,17,18, initially set to the zero state (Fig.2i, k), are unblocked.

A query signal is set up on the query bus 28 (FIG. 2m), in response to which the Start signal is issued on the launch bus 29 after response time tp (FIG. 26). The pulse former 15 generates a dual rectangular video recording pulse with a duty cycle of 2 (Fig. 2b), which drives the recording amplifier 12, zeroes the counters 21,22 of the result and triggers 16,17,18 are set in one state. This leads to the synchronous start of measuring generators 19, 20, producing counting pulses of frequency fo, which are passed to the counting inputs of the first and second counters 21,22 of the result, where they are accumulated (Figs. 2i, k). A request signal is removed via the request bus 28 (Fig. 2m), and a synchronization signal is set via the synchronization bus 30 (Fig. 2n).

At the output of the recording amplifier 12, current parcels are formed that pass through the medium of the magnetostrictive sound conductor 2 and excite in its medium under polarized magnets 5,6 elastic waves of double amplitude (Fig. 2d) due to the magnetomechanical transformation. Elastic waves propagate in both directions along the orthogonal branches of the sound cable 2 with the speed of the torsional wave VKp and reach the first and second lumped elements 7.8 readings through the desired time intervals of movement:

T,

 x

Iv

T - At VKP

u-chg-o)

"Cr

where x, ly is the distance between the polarizing magnets 5,6 and the read elements 7,8 along the coordinate axes X and Y.

Passing along the branches of the sound duct 2 under the readout elements 7,8, elastic waves (Fig. 2, d, e) induce read voltage pulses due to the magnetoelastic transformation on their outputs, which are amplified and transformed into right-angle video read pulses by selective shaping amplifiers. m 13.14 readings (Fig. 2g, h). Read signals

pass on the sync inputs of the first and second triggers 16, 17 of the control and transfer them to the initial state. Measuring generators 19,20 stop, and the next moment at the outputs of the first and second

the counters 21,22 of the result are set m and n - bit codes of the desired two-coordinate movement of the object

20

Nx Tx-fo, Ny Ty -fo, (2)

Forming signals on tires 31,32 results Moving X and Moving Y (Fig.2i, k). A query signal is set on request bus 28 (FIG. 2m). Other elastic waves, extending further along the branches of the sound duct 2, pass into its adjacent branches and through time:

Tiasli + b ± lxi T2 l + il ± iy (3)

V

cr

V,

cr

where (h + te) is the distance between the polarizing magnets 5,6 along the generatrix of the sound duct 2,

read by read elements 7.8. At the outputs of the selective shaping amplifiers 13,14 read signals are generated, which confirm the status of the control flip-flops 16,17. Acoustic acoustics 3,4 reaching the elastic waves undergo absorption and the formation, accumulation in the medium of the magnetostriction sound guide 2 of the acoustic energy of the reflected waves is not

a preset signal / interference ratio is maintained. This completes the conversion cycle and it enters the standby mode of the next conversion cycle, which starts at the initiative of the user and is performed as described.

In the event of a violation of the converter's operating mode in the form of overflow of the split grids of the counters 21,22, the error control trigger 18 is switched, and the Error signal is shown on the error control bus 33 (FIG. 2 l), informing the user about the unreliability

information in the current converter cycle.

The accuracy of measuring the movement of an object in comparison with the prototype is improved by reducing the component of the error due to the dispersion of the elastic wave velocity in the duct. The use of polarizing magnets as coordinate setters for the position of an object increases the dynamic characteristics of the DMPP and the lifetime, simplifies its kinematic scheme, which leads to the expansion of the field of application. Excitation of a double amplitude elastic wave in the environment of the magnetostriction sound duct of DMPP and an increase in the selectivity of the readout circuit increases the noise immunity of the conversion, and the use of self-monitoring increases the reliability of the converter.

Claims (1)

The invention Ultrasonic displacement transducer, comprising a base, a sound conductor fixed on the base, first and second acoustic absorbers installed at the ends of the acoustic conductor, first and second concentrated reading elements mounted on the acoustic conduit near the acoustic absorbers, connected to the outputs of the latter, the first and second selective read amplifiers and the pulse generator connected in series and the recording amplifier are of the same In order to improve the accuracy and reliability of displacement measurements, it is equipped with first and second polarizing magnets mounted on orthogonal branches of the sound duct with the possibility of longitudinal movement, first and second control triggers, error control trigger, first and second measurement generators , the first and second inverters, the first and second elements OR, the sound cable is made of magnetostrictive material and is galvanically connected to the output of the amplifier B, and outputs the first The second selective read amplifiers are connected respectively to the synchronous inputs of the first and second control triggers, their outputs are connected to the inputs of the first and second measuring generators and the inputs of the first OR element, the output of the latter serves as a query bus, the outputs of the measuring generators are connected respectively to the counting inputs of the first and second counters result, their bit outputs serve as the first and second result buses, transfer outputs of the first and second counters through the second element OR connected to the sync clock trigger error control, and the zero inputs are combined with the inputs of the first and second inverters and connected to the output of the pulse driver, the signal input of the latter serves as a trigger bus, and the control input serves as a control bus and is connected to the zero inputs of the first and second control triggers and the error control trigger, the single inputs of all the triggers are combined and connected to the output of the first inverter, the output of the error control trigger serves as an error control bus, the output of the second inverter serves as a synchronization bus, and the ring polarizing magnets are designed for kinematic connection with a moving controlled object. FIG. I Ј. ABOUT "Resolution U l m K-jrW MtMzm TyiShka eleven L , Y, Sync - / GGSh1 five Request / 7 U P L gd Editor T.Orlovska Phage .2 Compiled by S. Demin Techred M. Morgental 1765690 Wt zzzzzm. g shg 7 .. h- Jn-ji t Proofreader O. Kravtsov