SU1430256A1 - Contour control system of industrial robot - Google Patents

Abstract

The invention relates to the field of mechanical engineering and can be used in control systems of industrial robots. The purpose of the invention is to simplify the design and improve accuracy. The system includes a stepper motor 1, an n-bit counter — 26 pulses, a logic block 27, a memory block 28, a shift register 29, a stepper motor control block 5, the first 36 and the second 37 OR circuits, the working device simulator 40 with the sensor 38 mixing and the first button 39, the generator 41 clock pulses. In addition, an OR-NOT 42 element, an AND-NO 43 element, the second button 44 are entered into the system, and for each controlled coordinate there is a switch of 3 modes and a driver of 4 pulses. The introduction of the listed blocks and elements allows, when programming the robot, to read information about the position of the links of the manipulator from the windings of the executive stepper motor. 6 Il. (L 4: 00 About yu ate Oi

Description

The invention relates to mechanical engineering and can be used to control the movement of a working body of an industrial robot, for example in automating the welding process.

The aim of the invention is to simplify the design and improve the accuracy of fixing the position of the robot links by removing the information about the position of the robot links in the process of recording the program directly from the windings of the actuating step motor used in the learning process as a position sensor of the links.

FIG. I shows a functional system diagram; in fig. 2 - functional diagram of the pulse former; in fig. 3 - functional block diagram of the direction of motion; in fig. 4 - voltage plots of the direction of motion detection unit; in fig. 5 - functional block diagram of logic; in fig. 6 - the shift register is functional.

The system contains a stepper motor 1, the phase windings 2 of which and the common point of their connection are connected via a switch of 3 modes to the inputs of the driver 4 pulses. The inputs of the driver 4 pulses (bus A (1) -A (3) are the inputs of the amplifiers 5 (Fig. 2). The capacitors 6 and the resistors 7 are connected to the inputs of the amplifiers 5. The common connection point of the capacitors 6 is connected via the mode switch 3 via bus A (0) with the common connection point of the windings 2 of the stepper motor, as a result of which the windings 2 of the stepping motor and the capacitors 6 are connected in parallel on each phase. The common connection point of the capacitors 6 and resistors 7 is connected to the first outputs of the reference frequency generator 8. The outputs of the amplifiers 5 are connected to first entrances Dam demodulators 9, the second inputs of which are connected to the second outputs of the reference frequency generator 8. The outputs of the demodulators 9 are connected to the inputs of threshold devices 10, the outputs of which through the differentiating chains 11 are connected to the inputs of the movement direction determining unit 12 OR. The output of the circuit 13 OR is the first information output of the driver 4 pulses (bus B.). The direction determining unit 12 contains RS-triggers 14-16 input signals, elements 17-22 AND, elements 23, 24 OR, RS-trigger 25 sign. The inputs of busbar unit 12 (1) -G (3) are inputs of RS-flip-flops 14-16. The outputs of the RS flip-flop 25 of the sign Bi and B2 are the output of the direction-determining unit 12 and the second output of the driver 4, (bus B). The first output of the pulse former 4 pulses (B) is connected to the first input of the n-bit counter 26 pulses. The outputs of the p-bit counter 26 pulse

five

five

0

0

0 5

0

five

five

0

The combination (D) is connected to the first inputs of the logic block 27, the third input of which is connected to the second output of the pulse generator 4. The output of the logic block 27, which is n informational and two sign bits, is connected to the first input of the register 28 29 shift. Information bits on pin E in shift register 29 are connected to the first inputs of the subtracting counter 30, the outputs of which are connected to the inputs of the decoder 31, the output of which is connected to the first input of the first circuit 32 I. The output of the first circuit 32 AND is connected to the first inputs of the second circuit 33 AND and the third circuit 34 I. The second inputs of the second circuit 33 I (G |) and the third circuit 34 I (G2) are connected via the bus I to the sign bits of the first input of the register 29. The outputs of the second and third circuits 33 and 34 I are the first outputs the shift register 29 and are connected to the inputs of the ball control unit 35 gov engine. The second input of the first circuit 32 And the second input of the subtracting counter 30 is connected to the second input of the shift register 29. The third input of the counter 30 is the third input of the register 29.

The outputs of the control unit 35 of the scap motor are connected via a switch of 3 modes to the phase windings 2 and the common point of their connection of the stepper motor 1. The output of the nth digit of the pulse counter 26 is connected to the corresponding input of the first OR circuit 36, the output of which is connected to the first input of the second circuit 37 OR. The second and third inputs of the OR circuit 37 are connected respectively to the output of the displacement sensor 38 and the second output of the normally open contact of the button 39 Record of the working device simulator 40. The output of the OR circuit 37 is connected to the second inputs of the counter 26 and the logic block 27. The second inputs of the registers 29 are connected to the output of the clock generator 41, and the second outputs of the registers 29 are connected via bus K to the inputs of the element 42 OR NOT, the output of which is connected to the first input element 43 AND-NOT. The output of the element 43 is connected to the third inputs of the block 28 and the shift register 29. The second input of element 43 is connected via normally closed contacts of button 44 “Start with one of. the power supply terminals, which is also connected to the first output of the button 39.

The system works as follows.

When the power is turned on, the RS-flip-flops 14-16 of the directional detection unit 12, the para-pulse counter 26, the memory unit 28, the shift register 29 are set to zero (initial) state (the initial reset circuit conventionally not shown). At the same time, the RS-flip-flop 25 of the sign of the direction-determining unit 12 may have two states:

ten

15

go to one of the single or zero.

Before starting the programming of the robot, whose arm is at the starting point, the welding torch is replaced by the simulator 40 of the working body with the displacement sensor 38, and the switch 3 of the modes is set to the Record of the program. In this case, the windings 2 of the stepper motor 1 along the input buses A of the former of 4 pulses are connected in parallel to the capacitors of the former of the former of 4 pulses, forming a parallel circuit in each phase of the stepper motor. Since the common point and the junction point of the capacitors 6 and the windings 2 of the stepping motor of all circuits are connected directly to one of the first outputs of the reference frequency generator 8, and the connection points of the individual circuits to the input buses A are connected to the second of the first outputs of the reference frequency generator 8 the resistors 7 are then supplied with a sinusoidal voltage. The circuits are tuned in resonance to the frequency of the supply voltage.

When transferring hands

its programming from the starting point to the starting point of the weld begins to rotate the rotors of the stepper motors 1. The presence of teeth on the rotor of the stepper motor causes its reactance to change the reactance of the windings 2 of the stepper motor in a sequence depending on the direction of rotation of the rotor. This leads to the formation of amplitude-modulated signals at the output of the circuits, the frequency of the envelopes of which is proportional to the speed of rotation of the rotor of the stepping motor. The frequency of the sinusoidal waveform of the reference frequency generator 8 is selected an order of magnitude higher than the maximum frequency envelope of the amplitude-modulated signal at the output of the circuits. From the output of the circuits, the amplitude-modulated signals are fed to the input of the amplifiers 5, and after amplification to the first inputs of the demodulators 9. The second inputs of the demodulators 9 receive a sinusoidal voltage from the second outputs of the generator 8 of the reference frequency, which serve as a reference for the two-wavelength selection of the amplitude modulated signal envelope. The voltage envelope of the amplitude is set to one

tediously-modulated signals from the output :)., "." "", "" "",.

demodulators 9 are fed to the inputs of threshold devices 10. Schmidt's trigger are used as threshold devices, the threshold value of which is selected based on the condition that the last symmetric rectangular pulses are received at the output. The Schmidt triggers are configured in such a way that their trigger threshold is numerically equal to the constant component of the output signal of demodulator 9 and selected for each trigger when adjusted depending on the signal of the amplitude-modulated signal envelope.

Formed at the outputs of the Schmidt trigger 10, three sequences of symmetric rectangular pulses shifted relative to each other by 120 e. hail, are differentiated by chains 11 and, in the form of short pulses of positive polarity, are fed to the inputs of the OR circuit 13, and to the G-band to the inputs of the block 12 of the direction of motion detection. From the output of the circuit 13 OR a sequence of pulses of a unitary code is supplied via bus B to the first output of the driver 4 pulses.

The movement direction determining unit 12 operates as follows.

When a differential input chain 11 arrives at the T bus (1) of the first input signal (Fig. 3 and 4) via the S input, the RS flip-flop 14 is set to one and prepares for opening the elements 17 and 18 I. step on the bus G (2) of the second input

The robot in process 25 of the signal on the S-input RS-trigger 15 is set to one state and prepares elements 19, 20 for opening, and the signal from the output of element 17 I sets the RS-trigger RS-14 and zero to the zero state on the R input. through the element 23 OR is fed to the S input of the RS flip-flop 25 characters. When the third input signal arrives on the T bus (3), the RS-flip-flop 16 is set to one state at the W-input and prepares the elements 21 and 22 for opening,

C and the signal from the output of the element 20 And sets the RS-flip-flop 15 via the R-input to the zero state and through the circuit 23 OR enters the S-input of the RS-flip-flop 25 characters, duplicating the command from item 17 I. Then with this order the input of signals on the bus G is repeated.

If the input signals on the tires G come in reverse order, which corresponds to the rotation of the rotors of the stepping motors in the other direction, the signal arriving on the bus G (3) after the first input signal G (1), through elements 18 and 24 on the R input, sets triggers 14 and 25 to zero state. When a second input signal arrives on the G bus (2), RS flip-flop 15 via the S input

and

elements 19 and 20 are prepared for opening, and the signal from element 21I sets the trigger 16 via the R input to the zero state and, via element 24 OR, the trigger 25. On admission through the bus G (I)

55 of the first input signal, the trigger 14 at the S-input is set to one state and prepares elements 17 and 18 for opening, and element 19 AND issues a reset signal to the zero state.

45

trigger 15. This signal, via circuit 24, OR, sets in zero the status of a trigger 25 characters, duplicating the command from element 21I. With such a sequence of signals arriving on buses G, the process is repeated.

Thus, at any point in time, the RS flip-flop 25 of the sign of the direction-determining unit 12 is in one of the stable states. Signals (B | and B2) from the outputs of the trigger 25 of the sign arrive at the output of the block 12 of determining the direction of motion, which is the second output of the driver 4 pulses. From the first output of the imaging unit 4 pulses along the bus B, the pulses of the unitary code arrive at the first input of the n-bit of the bottom counter 26 pulses and accumulate in it. The capacitance of the n-bit impulse counter 26 determines the size of the approximation portion when the robot arm is moved from the starting point to the point of the weld start. When one of the p-bit pulse counters 26 overflows, at any coordinate of the robot, a signal appears through the first output of the corresponding pulse counter 26, which through the first OR circuit 36 OR the second OR circuit 37 enters the inputs of the logic block 27 and the memory block 28 ti.

As a result, information about the magnitude and sign of movement from the output of block 27 is recorded for each coordinate in the first cell of its memory area 28 (1) -28 (t) (t is the number of coordinates) of memory block 28.

The logic block 27 (FIG. 5) includes the n + 2-two-input element I, where n is the number of bits of the counter 26 pulses. The first two elements 27 (nf 1) and 27 (n + 2) of the logic unit are used to transmit information from the second output of the shaper 4 pulses about the direction of rotation of the shaft of the stepper motor 1, while the logical unit at the output of the element 27 (n + l) And corresponds to one direction of rotation of the shaft of the stepping motor 1, and the signal is a logical unit at the output of the element 27 (n + 2) AND - the second direction. The remaining elements 27 (1) -27 (p) And the logic block 27, the number of which corresponds to the number of bits of the pulse counter 26, transmits the pulses from the output of the counter 26 to the memory block 28 of information about the amount of movement of the robot's operating element. In each element And block 27 of the logic, one input is informational, and the second one is strobing. From the output of logic block 27, information about the size and direction of movement of the working body for each coordinate is read in a parallel n + 2-bit code and enters memory block 28 via its own bus and into its memory region.

The memory unit 28 is an addressless storage (storage) device of the stack type, in which information is stored in a memory cell sequentially, starting with cell number one, and each subsequent word is written into the next free cell. Simultaneously, from the output of the second circuit 37 OR, the signal of the nth digit of the corresponding counter 26 pulses goes to the second inputs of all n-bit counters 26 system pulses and sets them to the zero state on the falling edge, preparing to receive information about the movement of the robot arm the next approximation area. Thus, information on the movement of the working body of the robot is recorded when the robot arm is moved from the starting point to the start point of the weld. When the seam's starting point is reached, the operator presses and releases the 39 button “Record located on the simulator 40 of the working organ, thereby forming the last point of approximation and recording the information about the movement of the working organ, work on the last section of the approximation.

This is necessary to improve the accuracy of the system, since when the working body is mixed at the point of the start of the seam, the number of pulses received from the stepper motors in any of the pulse counters 26 in the last section of the approximation may not be enough to overfill it when the working body reaches seam starting points. In this case, the end of the approximation segment is determined by the first signal from the transposition sensor 38,

5 which may occur after the sensor passes a certain path. When playing the program, this leads to the loss of the point of the beginning of the seam.

When you press and release the button 39, the pulse from the power source through the circuit 37

 OR is fed to the second inputs of the logic block 27 and the memory block 28, controlling the process of recording information about the movement of the working element. At the same time, this pulse arrives at the second input of n-bit counters 26 of pulses, resetting them to the zero state.

Upon reaching the starting point of the weld, further training of the robot is carried out by rolling the sensor 38 to move the simulator 40 of the working organ along the line

0 welded joint. In this case, the signals of the sensor 38 are indications of the end of the approximation portions. Movement sensor 38 is, for example, a photoelectric sensor made in the form of a rolling wheel with openings. The illuminator is located on one side of the wheel, and the photodetector is located on the other. As the wheel rolls, the light flux modulates and a sequence of rectangular pulses is generated at the output of the displacement sensor 38. These pulses arrive at the second input of the second circuit 37 OR. From the output of the second circuit 37 OR, the pulses of the motion sensor 38 are fed to the second inputs of the logic block 27 and the memory block 28, controlling the process of recording information about the movement of the working element from the counters 26 pulses and information about the direction of rotation of the rotors of the scraper engines 4 stepper motor on tires F | and G2 is fed to the second inputs of the second circuit 33A and the third circuit 34I, respectively. When a different information other than zero is received at the output of the decoder 31, a single signal appears which, from the second output of the shift register 29, via bus K, through element 42 OR - does not establish a single signal at the output of element 43 NAND. On the front

displacement in the previous approximation region. This happens as follows.

A single signal from the output of the decoder 31 allows the passage of clock

the pulses in the shift register 29 are fed to the second input of the subtractive counter 30, as a result of which the information is subtracted until all the bits are

a zero signal also appears, which prohibits the passage of clock pulses to the output of the first circuit 32 I. Thus, pulses through block 27 to memory block 28. On one front of this signal, these pulses are simultaneously taken to receive in the second bath the information about the movement of n-bit counters 26 to the pulse-following section of the approximation, which

owls, carried out their reset to zero soy-saved at the output of block 28 to those

that notion. The frequency of the pulses from the dat-pores until the process of its movement of the stove 38 is carried out is determined by the need for recordings in the register 29, i.e. not yet the required accuracy of approximation. According to the window from - a r, or, e, o ,, raut, o uo g, .. ,,,, a.

In programming the weld area, using button 39, the last point of the weld joint is formed. Then the arm of the robot with the simulator 40 of the working organ is transferred to the pulses from the generator 41 to the output of the first starting point of the next step and the process circuit 32 I. At the same time, the clock programming is repeated. After completion of the robot programming throughout the product, the robot arm with the simulator 40 of the working organ returns to the original point-T-. - - gg - g-- ku. By pressing and releasing the button 39 of the counter 30 is not set to zero, the co-operator ends the formation of the prog. In this case, the output of the decoder 31 frame welding products.

To play the program in place of the simulator working body returns

welding torch. The switch 3 achieves equal pulses in the mode, proms is set to the position of the first circuit of the first circuit 32 And with the number of program outputs connected to the phase of the program impulses recorded in

windings of the stepper motor and the subtractive counter 30. After zeroing

A connection point for each coordinator of all meters 30, which corresponds to the timeline to the output of the control unit 35 for controlling the completion point of the test set by the negotiation engine. During reproduction of the homing in all coordinates, at the output of the elenrogram, at the output of the generator 41 of the clock 42 OR-NOT, single pulses are formed, a sequential pulse, and at the output of the element 43 AND-NOT -

short pulses, the frequency of the trace-zero signal, on the leading edge of which the horses are determined by a given velocity, is written to the counters 30

movement of the welding torch. For travel information on the following

the beginning of the program development is necessary at the 40th approximation stage. The occurrence of one-click and release button 44 “Start-up signal at the output of any one of the faults. The output of the elec-rators 31 formed at the same time leads to the establishment of the unit 43 AND – NOT a rectangular pulsatile signal at the output of element 43 and

the level of the logical unit of the pre-process is subsequently repeated. From the front, the front reads the input, and the first circuit 32 And the program pulses

formations of memory cells 28, and on the ass-g, ga.,. „, o ,,„ with, kg. ,,, „,,„ ..- ,, g. ,, about him - write the read information in the register 29 shift.

The information in memory block 28 is read from the first cell, with the numbers

all other words are reduced by one, one of the circuits 33 is kept

tsu. Readable information from block 28 or 34 I. In this case, information about

moving the working device from the output of the first circuit 32 I is fed to one of the first outputs of the shift register 29, and then to one of the inputs of the control unit 35 of the step, indicating the direction of rotation of the stepper motor. Control units 35

gatel Information about moving from a block to all coordinates is generated by the control

the memory 28 in the parallel write-voltage code, which is powered by the winding in the counter 30 of the register 29 of the shift 2 of the stepping motors 1. Welding (Fig. 6), and information about. the direction of the arrow from the starting point moves to

The movements of the working element are received at the first inputs of the second circuit 33A and the third circuit 34I. Depending on the condition of the tires Ж and Ж2, which determines the direction of rotation of the pinch motor, the first input of the shift register 29 enters in the open, in which the conversion parallel binary code to sequential as well as highlighting

rotation of the stepper motor on tires F | and G2 is fed to the second inputs of the second circuit 33A and the third circuit 34I, respectively. When a different information other than zero is received at the output of the decoder 31, a single signal appears which, from the second output of the shift register 29, via bus K, through element 42 OR - does not establish a single signal at the output of element 43 NAND. On the front

the front of this signal is read in the previous approximation. This happens as follows.

A single signal from the output of the decoder 31 allows the passage of clock

 r, or, e, o ,, raut, o uo g, .. ,,,, a.

pulses from the generator 41 to the output of the first circuit 32 I. At the same time, the clock im- T-. - - gg - r - pulses in shift register 29 are fed to the second input of subtractive counter 30, as a result of which information is subtracted until all bits

pulses from the generator 41 to the output of the first circuit 32 I. At the same time, the clock im- T-. - - YY - G-- counter 30 is not set to zero; a zero signal appears, which prohibits the passage of clock pulses to the output of the first circuit 32I. Thus, the output signal. In this case, the output of the decoder 31

yes the first circuit 32 And the program impulses

g, ga.,. „, about ,,„ with, kg. ,,, „,,„ ..- ,, g. ,,about

The movements of the working member are received at the first inputs of the second circuit 33A and the third circuit 34I. Depending on the conditions of the tires Ж and Ж2, which determine the direction of rotation of the pinch motor, to the starting point of welding and move along the line of the welded joint. At the end of the welding, the burner returns to one point.

Formula inventions

Not with the second input of the shift register, characterized in that, in order to improve accuracy and simplify the design, a second button, an OR-NOT scheme, an AND-NOT scheme are entered into it, and for each controlled coordinate there is a mode switch and a pulse shaper, the outputs of the phase windings of the stepper motor and the common point of their connection are connected to the outputs via a mode switch

The contour control system of an industrial robot containing a stepper motor for each controlled coordinate

and pleasingly connected n-bit -, and .. j --- -

counting pulses, logic block, memory block, U of a stepper motor control block and with

the thiohegist shift and the control unit of the step-inputs of the pulse former, the first

ti, shift register or uk whose output is connected to the first input

The p-bit pulse counter and the second output to the third input of the logic block, the third input of the shift registers and the third input of the memory block are connected to the output of the NAND circuit, the second input of which through the second button is connected to the power bus, which through the first button It is connected with the sensor “Er. with the third input T “P °“ ™ of the simulator of the working device, and the output from the second, the first input of the AND – NO circuit is connected to the output of the n-bit counter im- DOH of the OR – NO circuit, which connects the pulses of the logic unit and the memory block, yen, respectively, with the second inputs, the output of the generator of clock pulses of the connecting shift registers.

irij., 1 | .- -

engine, as well as a simulator of the working device with a displacement sensor and the first button, the first and second OR circuit, a clock pulse generator, while the output of the nth digit of the pulse counter is connected to the corresponding input of the first OR circuit, the output of which is connected to the first input of the second OR circuit, the second input of which is connected to the displacement sensor

15

Not with the second input of the shift register, characterized in that, in order to improve accuracy and simplify the design, a second button, an OR-NOT scheme, an AND-NOT scheme are entered into it, and for each controlled coordinate there is a mode switch and a pulse shaper, the outputs of the phase windings of the stepper motor and the common point of their connection are connected to the outputs via a mode switch

 -, and .. j --- -

 control unit stepper motor and with

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A

G

A

J ....,. one

JJ ... I

t

r

t t

-

rt

T

t

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Th

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Claims (2)

Claim The contour control system of an industrial robot, containing a stepper motor for each controlled coordinate and a series-connected p-bit pulse counter, logic block, memory block, shift register and stepper motor control block, as well as a working body simulator with a movement sensor and first button a first and a second OR gate, a clock pulse generator, the output of η-th pulse counter discharge soedi- ¹⁵ nen to a corresponding input of the first OR circuit, the output of the second circuit is connected to a first input s OR, the second input of which is connected to the displacement sensor of the working body simulator, and the output is connected to the second inputs of the η-bit pulse counter, logic block and memory block, the output of the clock generator is connected to the second input of the shift register, characterized in that, in order to improve the accuracy and simplify the design, a second button is introduced into it, an OR-NOT circuit, an AND-NOT circuit, and for each controlled coordinate there is a mode switch and a pulse shaper, while the outputs of the phase windings of the stepper motor and their common point The links through the mode switch are connected to the outputs of the stepper motor control unit and to the inputs of the pulse shaper, the first output of which is connected to the first input of the η-bit pulse counter, and the second output is connected to the third input of the logic block, the third input of the shift registers and the third input of the memory block are connected with the output of the AND — NOT circuit, the second input of which is connected via the second button to the power bus, which is also connected through the first button to the third input of the second OR circuit, the first input of the AND circuit is NOT connected to the output of the AND circuit AND-NO element, whose inputs are connected respectively to the second inputs of the shift registers. FIG. 2 faeZ Editor N. Horvat Order 5184/16 Compiled by O. Romanenko Tehred I. Veres Corrector L. Patai Circulation 908 Polisnoe VNIIIPI of the USSR State Committee for Inventions and Discoveries 113035, Moscow, Zh-35, Raushskaya nab., D. 4/5 Production and printing company, Uzhhorod, st. Project, 4