SU1430736A1 - Digital reading strain-measuring device - Google Patents

Abstract

The invention relates to a measurement technique and can be used to study the dynamic loading of manipulators of forest machines. The aim of the invention is to improve accuracy by providing a record of correlated random processes. The electrical signals are amplified by amplifier 3 and then fed to quantizing converter 4, which converts the analog signal to a discrete one. The discrete signal is then fed to the formers 6, 8, and 10 of the address code of the acting voltages, the angle along the gate of the boom, and the angle of the arm rotation, respectively. The address code through the switch P and the block 12 are transferred to the random access memory (RAM) 13, where the number written in the binary code appears. The binary code then goes on to the installation inputs of the counter-adder 14, where the unit is added to it, after which the new code is written in a short pulse to the RAM 13 at the same address. The time of action of the long pulse of the formation of the address code ends, and it brings the circuit to the initial state. The operation of the repeated measurement cycles is set using the clock generator 16. The strain gauge records in RAM 13 the number of amplitudes a that fall into a certain interval and S depending on the angles - rotation of the boom and p - rotation of the hand. 2 3.p. f-ly. 4 il .... o (L Jliib M O with

Description

The invention relates to a measurement technique and can be used to study the dynamic loading of manipulators of forest machines.

The aim of the invention is to improve accuracy by providing a record of correlated random processes.

Figure 1 shows the block diagram of the strain gauge; figure 2 - diagram of the quantizing converter; FIG. 3 is a diagram of an address code driver; Fig. 4 is a kinematic manipulator circuit.

The digital counting strain gauge contains in series, one connecting the power supply generator 1, the strain gauge 2, the amplifier 3, the quantizing converter 4 and the recorder 5; shaper 6 of the address code of the acting voltage - 1NII, the input of which is connected to the output of the quantizing converter 4; a boom angle sensor 7 connected in series and a shaper of an address code of a boom angle of rotation; a handle rotation angle sensor 9 connected in series and a shaper of a handle code angle of rotation of a handle 9; serially connected switch 11, zero-reset unit 12, random access memory (RAM) 13, counter-adder 14, decoder 15, the output of which is connected to the input of registrar 5; series-connected clock generator 16 and shaper 17 of the working pulse pattern, the output of which is connected to the inputs of the shaper 6 of the address code of the effective voltages and shapers 8, 10 of the address code of the angle of rotation of the boom and the arm, respectively; an information reading unit 18, the output of which is connected to the input of the switch 11; and a counter 19 resetting the RAM, the output of which is connected to the input of the zeroing unit 12; the output of the imaging unit 6 of the address code of the operating voltages is connected to the input of the switch 11, and the outputs of the imaging unit 17 of the working pulse pattern are connected to the input of the RAM 13 and the counter-adder 14.

The quantized converter 4 is made up of operational amplifiers (OA) 20-36, a voltage divider consisting of series-connected resistors 37-55; pe5

j

five

0 5 0 5 0

five

Sistors 37, 55 are variable, and resistors 38 to 54 have the same resistance; the inverted inputs of the operational amplifiers 20–36 are connected to the input of a quantizing converter 4, the non-inverted inputs are connected to a voltage divider, and the outputs of an op-amp 20–36 via resistors 56–71 to parallel-connected zener diodes 72–87 to them.

The formers 6, 8, 10 of the address code of the operating voltage, the angle of rotation of the boom and the arm, respectively, are made in the form of parallel

connected resistors 88 - 95, selector-multiplexer 96, the inputs of which are connected to resistors 88 - 95, a binary counter 97 connected to the address inputs of the selector multiplexer 96, a logical element 2I-HE 9B connected to the input of a binary counter 98; the output of the selector-multiplexer 96 is connected to the input of logic element 2I-HE 98, the second input of which is connected to the output of the clock about the generator 16 (not shown in FIG. 3),

Digital counting strain gauge works as follows.

The voltage or load arising in the structure under study is converted by a strain gauge 2 into electrical signals, which are amplified by an amplifier 3 and are fed to a quantizing converter 4, which converts the analog signal to a discrete one. This signal is displayed on the recorder 5 and simultaneously arrives at the shaper 6 of the address code of the active voltages. In accordance with the position of the boom angle 7 sensor in the shaper of the address code of the boom, the address code of the boom position is formed. In the third branch and in accordance with the position of the sensor 9 angle of rotation of the handle in the driver 10 of the address code of the handle, the address code of the position of the handle is formed.

The address code formed in the driver 6,8,10 through switch II and the unit 0 resetting RAM, performed, for example, on 2H-Pffi elements, goes to RAM 13. According to the address code, the number written in binary the code that goes to the adder

14, performed, for example, on binary-decimal reversible counters, km11p, their installation inputs. A binary code is applied to these installation inputs, the arrival of 1tsy from RAM 13. This code is transferred to the state of counter-accumulator 14 by a short pre-write pulse, then one is added to this state by adding one to the state of RAM. Now the new code is recorded in a short pulse into RAM 13 at the same address. After that, the time of action of the long pulse of the formation of the address code ends and it transfers the circuit to the initial state — the readiness to repeat the entire measurement cycle. The repeatability of the measurement cycles is set using the clock generator 16. The clock generator 16 allows 1.10, 100 and 1000 measurement cycles per second to be performed.

The shaper 17 of the working pulse diagram can be performed on binary counters, 2I-NOT elements and triggers. It forms a long pulse of forming the address code and short pulses of pre-recording in the state counter of RAM 13, a pulse of adding one to the state of RAM and a write pulse in RAM of the new state of counter-adder 4. After the passage of short pulses, the duration of the dt pulse is completed . Through a RAM reset unit 12, a RAM reset unit 19 is connected to the RAM 13, which can be performed, for example, on binary counters. He cleans OZ 13, i.e., enumerating the addresses of the RAM, he writes in

them logical O.

When reading information recorded in RAM 13, through switch 11 and RAM zeroing unit 12, information reading unit 18 connected to the switches is connected, which is used to generate a code for the proper voltages, handle angles and boom angles. in accordance with the set code at the output of the counter-adder 14, which when reading the information y) is not an adder, i.e. the impulse to add one to the state of the RAM is not perceived, and only the state of the RAM 13 is overwritten into the state of the 1h counter-adder and this state through the decoder 15 enters the recorder 5, which lights up a digit indicating the number of pulses recorded in the RAM 13 at a specific address set using block 18 information reading.

Figure 4 shows the kinematic manipulator circuit, which shows the angles ((boom turns) and | 5 (hand rotations), as well as the forces P, P, P ,,, P, and the stresses S. originating in the construction of the tweezer which

5 can be recorded using a digital counting strain gauge.

The digital counting strain gauge processes the acting stresses by the method of random ordinates taking into account the angles oi and p in the course of the experiment. Value & t - the frequency is polled discretely using a clock generator 16 (0, lj 0.01; 0, -001 SL), and the number of bits 5 in the ala splitting LN of maximum amplitude of the effect of the voltage S is 15.

When measuring, a digital counting strain gauge records in the RAM 13 coli 0 chesto amplitudes a, which fall into a certain dZ interval depending on the angles ci and (c.

The operation of the quantizing transducer 4 is performed as follows.

With the help of a voltage divider, the threshold is set for each op-amp 20 - 36 at the cost of the fact that the resistances of the resistors 38 - 54 are equal,

0 equal and voltage falling on them, i.e. the reference voltage is automatically divided into specific intervals. Using variable resistors 37, 55 can be adjusted

5, the expansion limits of these intervals, and with the help of resistor 46, the zero point is changed, i.e. the point relative to which the reference voltage changes. All the pulse inputs of the RAM are connected to one input, to which it supplies an analog signal. If the output voltage of an opamp is a positive voltage, then a logical unit is formed using a zener diode,

2 with a negative voltage, the zener diode forms a logical zero.

Shapers 6, 8, 10 address code are as follows.

Pulses with a frequency of 256 kHz from the clock oscillator 16 are constantly coming to the input of the 2I-HE 98 logic element. The 2I-HE 93 element can pass them to the C1 input of the binary counter 97 or delay it. It depends on what is present at the rtorium of the input of element 98 - logical O or 1 (1 - impulses pass t, O - do not pass). I

In the initial state, the logical input 1 is present at the second input of element 2I – HE 98, i.e. impulses pass to binary counter 97, but the counter counts them only when a long impulse arrives to enable the counter to binary counter 97. Continue counting): until the binary code coincides with the address inputs A, A , А „selector-multiplexer 96 with the position of the sensor, i.e. the code present at the inputs of the XO is X7; when they coincide, the output of the selector-multiplexer 96 is a logical O, which stops the passage of pulses to the binary counter 97 and the latter stops, and the outputs of the formers 6, 8 and 10 are present a code that corresponds to a certain position of the sensors 2, 7, 9. After the termination of a long pulse enabling the counting, the binary counter 97 is reset, i.e. the address code is cleared from the address outputs of the formers 6, 8, 10, the logical 1 appears at the output of the selector-multiplexer 96 — the driver is ready for the next cycle of the formation of the address code.

Claims (3)

1. A digital counter strain gauge containing a series-connected supply generator, a strain gauge bridge, an amplifier, a quantizing transducer and a recorder, which is also distinguished by the fact that it is equipped with a series-connected switch to increase accuracy by recording the correlated random processes. , by zeroing unit, random access memory, counter-adder and decoder, the output of which is connected to the recorder, sequentially g 10 g jq 25 pet 35 45 gQ gg connected by a clock generator of a working pulse pattern and a shaper of a voltage code of operating voltages, sequentially connected by a boom angle sensor and a shaper of an address code of the boom angle, the output of which is connected to the first input of the switch, and its second input is connected to the output of the shaper of the working pulse pattern serially connected the sensor of the angle of rotation of the handle and the driver of the address code of the angle of rotation of the handle, the code of which is connected to the second input of the switch, and the second Its input is with the output of the working pulse generator, the information reading unit, the output of which is connected to the third input of the switch and the readout memory counter, the output of which is connected to the second input of the zeroing unit, the second output of the imaging device / working pulse diagram is connected to the second the input of the counter-adder, the third output - with the second input of the random access memory, the output of the counter-adder is connected to the second input of the random access memory, output address code shaper operating voltage is connected to the fourth input switch quantizing output transducer is also connected to a second input of the address code existing stresses. 2. A strain gauge according to claim 1, characterized in that the quantizing converter is made up of sixteen parallel-connected operational amplifiers, a voltage divider consisting of series-connected resistors, the outermost of which are variable, and the rest have the same resistance, the inverted inputs of the operational amplifiers are connected to the input of a quantizing converter, the non-inverted inputs are connected to a voltage divider, and the outputs of the operational amplifiers through resistors with parallel connected to them tabilitronami connected to the output of the quantizing transducer. 3. The tensometer according to claim 1, about t l and h a- yu y and with the fact that shapers the address code of the operating voltage, the angle of rotation and the arm are eight parallel connected resistors, a multiplexer selector with inputs connected to the resistors, a binary counter connected to the address inputs of the multiplexer selectors, logic element 2I-HE connected to the input of the binary counter, the output of the selector-multiplexer is connected to the input of the logic element 2И-NOT, the second input of which is connected to the output of the clock generator. 7O -c: -Vcf f 87