RU1797094C - Digital servo system - Google Patents

Abstract

The invention relates to digital servo systems with non-contact DC motors and can be used in manipulation work and other automation devices as executive servo systems. The purpose of the invention is to increase speed. The digital tracking system comprises a mismatch meter 1, a module isolation unit2, a first threshold element 3. a first multiplication unit 4, a digital pulse-width converter 5, a phase switch 6, a synchronous electric motor 7, a rotor position sensor 8, a second threshold element 9, the second block 10 multiplication, the Converter 11 code is the pulse frequency. The object of the invention is achieved by introducing the connections of the second input and output of the first multiplication unit, respectively, with the input of the digital servo system and the input of the digital wide-pulse converter and changing the design of the latter. 4 ill.

Description

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The invention relates to digital servo systems with non-contact DC motors (DCBM) and can be used in manipulation robots and other automation devices as actuator servo systems.

The purpose of the invention is to increase speed.

In FIG. 1 is a functional diagram of a digital tracking system; in FIG. 2 is a functional diagram of a digital pulse-width converter; in FIG. 3 is a diagram of the main coordinates of the prototype system (Fig. 3a) and the digital tracking system (Fig. 3,6) during the development of a spasmodic input signal; in FIG. Figure 4 shows vector diagrams of the MJI-HHT fluxes of the stator Фс and rotor Фр for the prototype system (Fig. 4, a) and digital: tracking system (Fig. 4,6) in the BJTT mode (t tn -1); at the time of switching (t tn) and in the discrete-step mode of the system (t tn + + 1), (t tn + 2). .

The digital tracking system comprises- (Fig. 1) a mismatch meter 1, a module isolation unit 2, a first threshold element 3, a first multiplication unit 4, a digital pulse-width converter 5, a b phase switch, a synchronous motor 7, a rotor position sensor 8, a second threshold element 8, a second multiplication unit 10, a pulse-frequency-code-converter 11.

The digital pulse-width converter 5 contains (Fig. 2) an address generating unit 12, an address converting unit 13, a first adder 14, a mismatch meter 15, a mismatch limiting unit 16, a second adder 17, a modulation depth code converter 18 to phase control codes pulses, pulse-width modulator 19, generator, 20 carrier frequency ,.

The digital tracking system operates as follows.

Blocks 12, 13 when the system is in continuous control mode are disabled and zero arrives at the second input of adder 14. When the system enters the step mode, in block 12, the current value of the rotor angle code is recorded, which is subsequently changed by pulses from the converter 11. Depending on the error sign, the code corresponding to the angle is added to the output code of block 12 in block 13 ± 90 ° el. Thus, a stator field is formed, the magnetic flux of which FS is perpendicular to the magnetic flux of the rotor Фр, and the moment.

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the engine being developed in this case is braking. In any mode of operation of the system, the code of the angular position of the stator is generated at the output of the adder 14, and the code of the meter 15 - at the output of the meter, the code of the angle of inconsistency between the fields Фс and Фр, which is limited by block 16 to within ± 90 ° ed. degree in, which prevents the engine from falling out of synchronism. The converter 18 contains codes of durations and signs (e.g. harmonic) of pulses of m functions shifted by an angle of 2 / t radians, which are fed to the inputs of modulator 19, where they are converted into pulse-width modulated pulse sequences.

Block 13 can be performed by synthesis of combinational circuits using arithmetic logic devices; in step mode, it performs an addition (subtraction) operation on the output code of block 12 and a binary representation of an angle of 90 e. hail, which is uniquely determined by the transfer coefficient of the rotor position sensor and the number of pole pairs of the electric machine.

The combination schemes for the signals of the error sign sign A 0 and the output signal AUn of the threshold element Dip allow you to choose one of the functions of the arithmetic logic device (ALU) for implementation: A + B or A - B, where A are the inputs of the ALU to which the code arrives block 12; B - inputs of the ALU, the code for which corresponds to an angle of 90 el. In static mode, the system error is zero, threshold element 9 has an output value of 1, and threshold element 3 has a zero signal. As a result, the first input of the adder 14 receives a zero signal. Since the system error is zero, there are no pulses at the output of the converter 11, and the modulator 19 generates sequences of pulses of a constant duty cycle. In this case, the stator field is motionless, maximum in magnitude, and its rotation angle relative to the rotor is equal to а - aresinMH / M0. Thus, in the idle mode, the engine develops a synchronizing moment that fully compensates for the moment of load on the shaft at zero mismatch, i.e. This system, like the prototype, has astatism with respect to moment disturbances.

When applying to the input of the system a jump-like setting action Df, the code of the mismatch module I D0 is greater than the threshold of the threshold element 3. As a result, there is a high level at its output, and at the output of the threshold

element 9 is low. The Converter 11 is disconnected from the block 12 and the driving action is applied to the first input of the adder 14, the second input of which 0, because blocks 12, 13 are turned off by the signal AUn. At the input of the meter .15 there is a difference code Дф - Л # о, and if it is larger in absolute value of the code corresponding to 90 electrical degrees, then it is limited to block 16, after which it is added to the rotor angle code. Thus, the system operates continuously. As the mastering effect is worked out, the mismatch also decreases at some time t tn and the threshold elements 3 and 9 are switched over. In this case, the current value of the sensor code is recorded in block 12, the output code of block 4 is reset, the converter 11 is connected through block 10 to block 12, in addition, the operation mode of block 13 is determined from the signals of the DPP and sign. So that the magnetic flux Фс is rotated by 180 electric degrees, i.e. in block 13, the code corresponding to the angle of 90 degrees is arrived at D # 0, and subtracted at ID0 0, to the output code of block 12. The engine starts to brake effectively, because floor of the stator and rotor perpendicular. Due to nonzero mismatch, pulses are received from converter 11 and the stator field continues to rotate in the same direction, while the motor continues to brake.

With non-deterministic moments of disturbance, the rotor field in the prototype system can go forward, which will lead to an increase in the mismatch between the fields by more than 90 degrees, which in turn will cause the engine to fall out of synchronism. Therefore limiter 15

Claims (1)

SUMMARY OF THE INVENTION A digital tracking system comprising a mismatch meter connected through a series-connected module selection unit, a first threshold element to a first input of a first multiplication unit, an output of a module selection unit through a second threshold element connected to a first input of a second multiplication unit, to a second input of which a code-to-pulse converter is connected to the output of a mismatch meter connected by a summing limits, the absolute value between the fields $ c and s at the level of e, degrees, which causes the preservation of the greatest brake. current moment and prevents disruption of the system. These commutations lead to the fact that, starting from the time t tn, the engine and the system as a whole begin to work as stepping. This mode is characterized by the fact that the magnetic field of the stator windings of the motor moves discretely in space, one step with the arrival of each new pulse from the converter 11, the frequency of which is determined by the mismatch D # and the transformation law. The sign of the moment on the motor shaft is determined by the mutual orientation of the magnetic fluxes of the rotor Фр and the stator Фс. This mode of operation of the system will continue until the time t IK, when the mismatch of the system D # becomes equal to zero D # 0. In this case, the rotation angle of the stator magnetic flux is relatively equal to: , Mn a arcsin -j-gMO Thus, a 180 degree rotation of the stator polarity at the moment of transition from continuous to step mode and the use of saturation of the mismatch between the stator and rotor fields can significantly increase the speed of the digital tracking system. The proposed digital tracking system can be most effectively used in handling robots where high speed is required, overshoots are unacceptable, and the load moment on the motor shaft varies widely. an input with the input of a digital servo system, a digital pulse-width converter, which contains a series-connected address generation unit, an address conversion unit connected by a sign input to the sign input of a digital pulse-width converter, and a control input to its control input and control the input of the address generation unit, the frequency and address inputs of which are the frequency input and the feedback input of the digital pulse-width pulse a converter, a serial converter of the modulation depth code into phase control pulse codes, a pulse-width modulator connected by a clock input to the output of the carrier frequency generator, and an output to an output of a digital pulse-width converter, connected via series-connected phase switch , synchronous electric motor, rotor position sensor with subtracting input of disbalance meter and feedback input of digital pulse-width converter, controlling frequency the sign and sign inputs of which are connected respectively to the outputs of the second threshold element, the second multiplication unit and the sign bit of the output of the mismatch meter, which is due to the fact that. in order to improve performance, the input of the digital tracking system is connected to the second input of the first multiplication unit, connected by the output to the reference input of the digital pulse-width converter, into which two adders, a mismatch meter, and a mismatch limiting block, are entered a pulse converter through a series-connected first adder, a mismatch meter, a mismatch limit block, the second adder is connected to an address input device, the output of the address conversion unit is connected to the second input of the first adder, and the address input of the address generation unit is connected to the second inputs of the mismatch meter and the second adder. Figz about Fs / m „-; ( Yes: ,, # Ј and / i-in. Zv S-R-, lЈ b ; AND € /