JP7214976B2 - Vibration suppression device and linear motor control device - Google Patents

Description

The present invention provides, for example, a linear compressor that reciprocates a piston by a linear motor to compress gas, and provides a vibration suppressing device for reducing mechanical vibration generated by gas force accompanying the reciprocating motion of the piston, and the vibration suppressing device. The present invention relates to a linear motor control device with a suppressor.

FIG. 5 shows a drive system for a linear compressor that constitutes a refrigerator, and is described in Patent Document 1. As shown in FIG.
5, 101 is a DC power supply, 102 is a single-phase inverter composed of semiconductor switching elements _Q1 to _Q4 , 103 is a linear compressor, 104A and 104B are linear motors, 105A and 105B are pistons, 106 is cylinders, and 107 is pistons. It is a position sensor for obtaining position information for preventing collision between 105A and 105B.
In this prior art, an AC voltage is supplied to the drive coils of linear motors 104A and 104B by a single-phase inverter 102 to reciprocate pistons 105A and 105B in mutually opposite directions, thereby compressing the gas inside cylinder 106 at a predetermined cycle. , is expanded and supplied to the expander.

Generally, in a linear compressor, gas is repeatedly sucked, compressed, and discharged by reciprocating motion of a piston, and the gas force (gas pressure) changes periodically. Since this change in gas force vibrates the housing of the compressor and the like, causing noise and malfunction, it is an important issue to suppress this mechanical vibration.

From the above background, as shown in Patent Documents 2 and 3, conventional techniques for suppressing mechanical vibration of refrigerators and the like are publicly known.
FIG. 6 shows a control system for a Stirling refrigerator described in Patent Document 2. As shown in FIG.
6, 200 is a fundamental frequency vibration controller, 201 is an amplitude/phase adjuster, 202a and 202b are subtractors, 203a and 203b are position servo compensators, 300 is a Stirling refrigerator, 301 is a compressor, and 302a and 302b are Linear motors 303a and 303b are pistons, 310 is a helium flow path, 321 is an expander, 322a and 322b are linear motors, 323 is a piston, 324 is a balance section, and 325 is a cold storage device. Here, stroke commands (position commands) Sa and Sb of linear motors 302a and 302b corresponding to pistons 303a and 303b of compressor 301 are input to fundamental frequency vibration control unit 200, respectively.

In this prior art, the position detection values Pa and Pb of the pistons 303a and 303b are fed back to the fundamental frequency vibration control unit 200, and the position servo compensators 203a and 203b are operated so as to eliminate the deviation from the stroke commands Sa and Sb. Drive commands Ma and Mb for linear motors 302a and 302b are generated. Thereby, the positions of the pistons 303a and 303b can be adjusted in real time to reduce the mechanical vibration of the compressor 301. FIG.

Also, FIG. 7 is a configuration diagram of the vibration suppression system described in Patent Document 3. As shown in FIG.
This prior art suppresses the mechanical vibration of the main machine 410 driven by the power control circuit 408 by driving the motor 412 in the active vibration balancer 411 attached to the main machine 410 .

7, a digital processor 400 includes a command input section 401, a control algorithm 402, and a D/A conversion section 403. A command output from the D/A conversion section 403 causes a main machine 410 to operate via a power control circuit 408. driven.
On the other hand, a vibration sensor 413 detects the vibration of the combination of the main body machine 410 and the active vibration balancer 411, and the detection signal is sent through the A/D converter 405 in the digital processor 400 to the adaptive balancing signal generators 404a and 404a. 404b, . . . , 404n. Adaptive balanced signal generators 404a, 404b, . , generate an adaptively balanced signal with nω. These adaptive balanced signals are combined by adder 406 and input to motor control section 409 via D/A conversion section 407 . By driving the motor 412 of the active vibration balancer 411 by the motor control unit 409, the vibration of the fundamental wave component ω and the harmonic components 2ω, .

Japanese Patent No. 4096665 ([0016] to [0019], FIG. 1, etc.) US Pat. No. 5,535,593 (FIG. 2a, etc.) Japanese National Publication of International Patent Application No. 2015-530638 ([0019] to [0030], FIG. 1, etc.)

According to the prior art of Patent Document 2, it is possible to suppress the fundamental wave component of vibration by independently controlling the position and stroke of each piston 303a, 303b in a closed loop, but it is impossible to suppress the harmonic component. is.
In addition, in the prior art of Patent Document 3, theoretically, from the fundamental wave component to the harmonic components of multiple orders, the stability of the adaptive filter algorithm in the adaptive balanced signal generators 404a, 404b, Due to problems such as the processing capacity of the processor 400, it has been difficult to reliably suppress mechanical vibration at low cost.

SUMMARY OF THE INVENTION Therefore, the problem to be solved by the present invention is a vibration suppressing device capable of reliably suppressing over a wide frequency range mechanical vibrations generated by the operation of an actuator including a linear motor, and a linear motor equipped with this vibration suppressing device. The object is to provide a control device.

In order to solve the above problems, a vibration suppressing device according to claim 1 is a vibration suppressing device that suppresses vibration of a machine body generated by the operation of an actuator including a linear motor by controlling the linear motor,
disturbance estimating means for estimating a periodic disturbance based on the fundamental wave component and the harmonic component of the drive frequency of the linear motor extracted from the signal related to the vibration of the machine body;
periodic disturbance suppression calculation means for generating a correction command for canceling the periodic disturbance by feeding back the periodic disturbance to the periodic disturbance command;
addition means for adding a main command for driving the linear motor and the correction command;
means for driving the linear motor according to the output of the adding means;
with
When a vibration detection signal of the machine body can be obtained, the vibration detection signal is used as the signal related to the vibration of the machine body, and when the vibration detection signal of the machine body cannot be obtained, the fundamental wave component of the vibration is used. and a vibration suppression device that selects to use a signal based on previously measured and stored data of the harmonic component,
The machine body is a linear compressor,
The linear compressor is
Having first and second actuators as the actuators,
each of the first and second actuators includes a linear motor and a piston driven by the linear motor to reciprocate in opposite directions;
The signal related to vibration of the machine body is a signal related to vibration generated in the housing of the linear compressor due to a known periodic change in gas force accompanying the reciprocating motion of the piston in the first and second actuators. characterized by being

A vibration suppressing device according to claim 2 is the vibration suppressing device according to claim 1, wherein the linear motor constituting the first actuator is driven according to the main command, and the linear motor constituting the second actuator is driven according to the main command. It is characterized in that it is driven according to the output of the adding means .

A vibration suppressing device according to claim 3 is the vibration suppressing device according to claim 1 or 2,
The disturbance estimating means estimates the periodic disturbance from a signal related to the vibration of the machine body using a periodic disturbance observer, and the periodic disturbance suppression calculating means cancels the periodic disturbance estimated by the periodic disturbance observer. It is characterized by calculating a correction command.

A vibration suppressing device according to claim 4 is the vibration suppressing device according to claim 3 , wherein the main command and the correction command are current commands or voltage commands .

According to claim 5, there is provided a linear motor control device for supplying AC power to said linear motor using the output of said adding means in the vibration suppressing device according to any one of claims 1 to 4. It is characterized by controlling a converter .

According to the present invention, the fundamental wave component and the harmonic component are extracted as disturbance from the vibration detection signal of the machine body or the signal based on the data previously measured and stored for the fundamental wave component and the harmonic component of the vibration of the machine body. However, by adding a correction command calculated so that these components become 0 to the main command and controlling the actuator, vibration of the machine body can be reliably suppressed over a wide frequency range.

1 is a block diagram showing a schematic configuration of an embodiment of the present invention; FIG. FIG. 4 is a waveform diagram showing the relationship between the piston position and the gas force in the linear compressor; 1 is a block diagram of a vibration suppressing device when driving a linear compressor using a current command in an embodiment of the present invention; FIG. It is a block diagram of a periodic disturbance observer, a periodic disturbance suppression calculator, etc. in the Example of this invention. 1 is a configuration diagram showing a drive system for a linear compressor disclosed in Patent Document 1; FIG. 1 is a configuration diagram showing a control system for a Stirling refrigerator described in Patent Document 2; FIG. 1 is a configuration diagram showing a control system for a Stirling machine described in Patent Document 3; FIG.

An embodiment of the present invention will be described below with reference to the drawings.
First, FIG. 1 is a block diagram showing a schematic configuration of a vibration suppressing device according to this embodiment. This vibration suppressing device is used, for example, in a linear compressor that constitutes a Stirling refrigerator to suppress vibration generated by reciprocating motion of a pair of pistons that constitute an actuator.

In FIG. 1, a vibration suppression control section 10 comprising a digital processor or the like is provided with a vibration sensor 11 or a gas force characteristic curve 12 .
The vibration sensor 11 detects vibration of the housing of the machine body 30 of the linear compressor, and the vibration detection signal is input to the terminal a of the selector 13 .
If the vibration suppression control section 10 does not have the vibration sensor 11 , data based on the gas force characteristic curve 12 in the memory is input to the terminal b of the selector 13 . The gas force in the cylinder changes periodically due to the reciprocating motion of the piston in the machine body 30, and this causes mechanical vibration. Therefore, these data can be stored in memory in advance as the gas force characteristic curve 12 .

The selector 13 selects the input of the terminal a or the terminal b, and through the terminal c, the primary component (fundamental wave component) filter 14 ₁ , secondary component filter 14 ₂ , . . . , n-order component filter 14 _n output to
Each order component (component extracted or estimated as disturbance) extracted by each filter 14 ₁ to 14 _{n is} input to subtraction means 15 ₁ , 15 ₂ , . are calculated, and these _deviations are input to the primary vibration component suppression controller 16 ₁ , secondary vibration component suppression controller 16 ₂ , .
_Each suppression controller _{16 1} , 16 ₂ , . _{2 ,} .

The command signals 1 and 2 include as information the drive frequency, current command or voltage command for the main drive actuator 31 and the balancing actuator 32 provided in the machine body 30, and command signal 1 and command signal 2 (main command) A signal obtained by adding the correction command is input to the power amplifier 20 . A power amplifier 20 supplies power to a main drive actuator 31 and a balancing actuator 32, respectively.
Here, the main drive actuator 31 is composed of a linear motor 302a and a piston 303a like the compressor 301 in FIG. 6, and the balancing actuator 32 is similarly composed of a linear motor 302b and a piston 303b.
As shown in FIG. 1, one power amplifier 20 may drive the main drive actuator 31 and the balancing actuator 32, or the actuators 31 and 32 may be driven by individual power amplifiers.

Next, an example embodying this embodiment will be described with reference to FIGS. 2 to 4. FIG.
When the machine body 30 is a linear compressor of a refrigerator, the mechanical vibration generated in the housing due to the reciprocating motion of a pair of pistons is mainly due to (1) the inertial forces generated by the opposed pistons are not equal; and (2) periodic gas force acts as a disturbance due to the reciprocating motion of the piston.
Of these, (1) can be completely canceled out by controlling the thrust by current-controlling the individual pistons. Further, it is known that the gas force of (2) changes periodically according to the piston position, as shown in FIG. These points are also disclosed in Huiming Zou, "Experimental investigation and performance analysis of a dual-cylinder opposed linear compressor", Journal of Mechanical Science and Technology, August, 2011 (Fig. A.1).

ここで、周期的なガス力Ｆ_ｆｇａｓの直流成分は、０［Ｎ］である。また、数式１において、ａ_ｎ，ｂ_ｎはガス力のフーリエ係数を示す。 A Fourier series expansion of the periodic gas force shown in FIG.

Here, the DC component of the periodic gas force F _fgas is 0 [N]. In Equation 1, an and _bn represent Fourier _coefficients of gas force.

Therefore, if a correction command that cancels the disturbance (gas force) of a predetermined frequency that suppresses the movement is added to the main command that moves each piston in a predetermined direction, a force that counters the disturbance is generated to suppress the vibration. be able to. In constructing the vibration suppressing device, for the sake of convenience, the disturbance acts only on one piston drive system (equivalent to the balancing actuator 32 in FIG. 1) and acts on the other piston drive system (also the main drive actuator). 31) are not affected.

FIG. 3 shows a case where a linear compressor 30A (corresponding to the machine main body 30 in FIG. 1) is driven by giving a sinusoidal current command as a main command to the vibration suppression control section 10A (corresponding to the vibration suppression control section 10 in FIG. 1). It is a block diagram of a vibration suppression device.
In FIG. 3 and FIG. 4 described later, the current command is used as the main command and the correction command, but the voltage command may be used. Further, although mechanical vibration is detected by the vibration sensor 11 in FIG. 3, the gas force characteristic curve 12 may be used instead of the vibration detection signal by the vibration sensor 11 as shown in FIG.

The linear compressor 30A includes two voice coil motors 31a and 32a, which are energy-saving linear motors, pistons (mechanical systems) 31c and 32c driven by the respective motors 31a and 32a, and addition means 31b and 32b. ing. A pair of pistons 31c and 32c are arranged to face each other and reciprocate in opposite directions to compress the gas in the internal space of the cylinder (not shown).

In the above configuration, the voice coil motor 31a, adding means 31b and piston 31c constitute the main drive actuator 31 in FIG. As described above, the gas force as a disturbance is input to one adding means 32b, and the explanation continues assuming that it acts only on the balancing actuator 32. FIG.

Mechanical vibration of the housing of the linear compressor 30A is detected by the vibration sensor 11, and a vibration detection signal (acceleration A _det ) is output. This acceleration A _det is input to the periodic disturbance observer 50 in the vibration suppression control section 10A to estimate the periodic disturbance.
The periodic disturbance observer 50 includes a frequency component extractor 51 for extracting the fundamental wave component and the harmonic component of the driving frequency of the balancing actuator 32 (voice coil motor 32a) included in the acceleration _Adet , and the disturbance from these frequency components. and an estimating inverse system 52 .

The inverse system 52 is P _2n ⁽ s)·P _{2n −1} A system with a transfer function P _2n ⁻¹ (s) satisfying (s)=1. This inverse system 52 is designed including a current feedback control system, and has transfer characteristics according to the frequency component of the vibration to be suppressed.

The disturbance estimated by the periodic disturbance observer 50 is input to the periodic disturbance suppression calculator 60 and fed back to the periodic disturbance current command (usually 0) via the subtraction means 61 and 63 and the filter 62 to obtain the correction command (correction current command) is generated. A filter having the same characteristics as the filter 62 is used for the frequency component extraction unit 51 so that the value extracted by the frequency component extraction unit 51 described above follows the periodic disturbance current command.

The corrected current command output from the periodic disturbance suppression calculator 60 is added to the sinusoidal current command (main command) by the adder 15 and input to the current controller 74 via the subtractor 73 in the power amplifier 20A. . Also, the sinusoidal current command is input to the current controller 72 via the subtraction means 71 .
The current controllers 72 and 74 respectively generate control commands so that the currents of the voice coil motors 31a and 32a follow the respective current commands and output them to the PWM inverters 21 and 22. These PWM inverters 21 and 22 control the voice The coil motors 31a and 32a are respectively driven to control the reciprocating motion of the pistons 31c and 32c.

Next, FIG. 4 is a block diagram of the periodic disturbance observer 50, the periodic disturbance suppression calculator 60, etc. in FIG.
In FIG. 4, compressor drive system 80 consists of main drive system 81 and balancing system 82 . The main drive system 81 is a block including the current controller 72, the PWM inverter 21, the voice coil motor 31a, the adding means 31b, the piston 31c, etc., shown in FIG. This block includes a PWM inverter 22, a voice coil motor 32a, an addition means 32b, a piston 32c, and the like. 4, illustration of the vibration sensor 11 of FIG. 3 is omitted.

4, the real part A _an and the _imaginary part Extract the _Abn .

In order to calculate Equation 2, as shown in FIG. 4, the acceleration A _det is doubled, and the result of multiplication by the cosine cos (nωt) and sine sin (nωt) of the fundamental wave component and harmonic component of the drive frequency is low-passed. The real part A _an and the imaginary part A _bn of the n-order frequency component of the acceleration A _det are extracted by passing through the filter G _F (s). Here, A and ω respectively correspond to the amplitude and frequency of the sinusoidal current command.
The oscillating components contained in A _an and A _bn are the parts marked with “*” in Equation 2, and these oscillating components are cut off by the low-pass filter G _F (s). In the right side of Equation 2, a _an and a _bn are amplitudes, and a ₀ is a constant.

Further, the actual system 83 in FIG. 4 has the balance system 82 consisting of the voice coil motor 32a, the piston _32c , the vibration sensor, etc., as described above. has a frequency transfer characteristic of the entire system of The transmission characteristics from the position of the piston 32c to the housing of the linear compressor 30A can be obtained by an identification test.

Assuming that the transfer function of the actual system 83 is P _2n (s), the output of the frequency component extractor 51 is multiplied by the inverse model of the transfer function P _2n ⁻¹ (s), and the input current estimated value i Compute the real part (real part estimate) _Ian ^# and the imaginary part (imaginary part estimate) _Ibn ^# of _n ^# . Since these estimated values I _an ^# and I _bn ^# contain periodic disturbance components due to gas force, the real part current command I _an ^* and the imaginary part current command I _bn passed through a low-pass filter G _F (s) By subtracting ^* respectively, the real part dI _an ^# and the imaginary part dI _bn ^# of the periodic disturbance current estimate can be obtained.

By feeding back the real part dI _an ^# and the imaginary part dI _bn ^# of the periodic disturbance current estimation value described above to the real part dI _an ^* (=0) and the imaginary part dI _bn ^* (=0) of the periodic disturbance current command, respectively , real part current command I _an ^* and imaginary part current command I _bn ^* for suppressing period disturbance are obtained.
By multiplying cos(nωt) and sin(nωt) to these real part current command I _an ^* and imaginary part current command I _bn ^* and synthesizing them, an n-th order correction current command i _cn ^* is generated. This correction current command i _cn ^* is given to the actual system 83, and the voice coil motor 32a is driven by using the result of adding the disturbance component i _neq2 and the sinusoidal current command (main command) Asin(ωt) as the current command. It is possible to suppress the mechanical vibration caused by the gas force that changes with the reciprocating motion of 32c.

3 and 4 are merely an embodiment of the present invention. For example, instead of the periodic disturbance observer 50, a band-pass filter or the like can be used to extract the fundamental wave component and harmonic components of each order of mechanical vibration. Any filter may be used.

INDUSTRIAL APPLICABILITY The present invention can be used not only for linear compressors but also as vibration suppressing devices for various machine bodies equipped with actuators having linear motors.

10, 10A: Vibration suppression controller 11: Vibration sensor 12: Gas force characteristic curve 13: Selector 14 ₁ : First order component filter 14 ₂ : Second order component filter 14 _n : n order component filter 15 ₁ to 15 _n : Subtraction Means 16 ₁ : primary vibration component suppression controller 16 ₂ : secondary vibration component suppression controller 16 _n : n-order vibration component suppression controller 17: addition means 20, 20A: power amplifier 21, 22: PWM inverter 30A: linear Compressor 30: Machine main body 31: Main drive actuator 32: Balance actuator 31a, 32a: Voice coil motor 31b, 32b: Addition means 31c, 32c: Piston 50: Periodic disturbance observer 51: Frequency component extractor 52: Inverse system 61, 63, 71, 73: subtraction means 62: filter 72, 74: current controller 80: compressor drive system 81: main drive system 82: balancing system 83: real system 91: separation means S ₁ to S _n : switch

Claims (5)

A vibration suppressing device for suppressing vibration of a machine body caused by operation of an actuator including a linear motor by controlling the linear motor,
disturbance estimating means for estimating a periodic disturbance based on the fundamental wave component and the harmonic component of the drive frequency of the linear motor extracted from the signal related to the vibration of the machine body;
periodic disturbance suppression calculation means for generating a correction command for canceling the periodic disturbance by feeding back the periodic disturbance to the periodic disturbance command;
addition means for adding a main command for driving the linear motor and the correction command;
means for driving the linear motor according to the output of the adding means;
with
When a vibration detection signal of the machine body can be obtained, the vibration detection signal is used as the signal related to the vibration of the machine body, and when the vibration detection signal of the machine body cannot be obtained, the fundamental wave component of the vibration is used. and a vibration suppression device that selects to use a signal based on previously measured and stored data of the harmonic component,
The machine body is a linear compressor,
The linear compressor is
Having first and second actuators as the actuators,
each of the first and second actuators includes a linear motor and a piston driven by the linear motor to reciprocate in opposite directions;
The signal related to vibration of the machine body is a signal related to vibration generated in the housing of the linear compressor due to a known periodic change in gas force accompanying the reciprocating motion of the piston in the first and second actuators. A vibration suppressing device characterized by: In the vibration suppressing device according to claim 1,
A vibration suppressing device, wherein a linear motor constituting said first actuator is driven according to said main command, and a linear motor constituting said second actuator is driven according to the output of said adding means. In the vibration suppressing device according to claim 1 or 2,
The disturbance estimating means estimates the periodic disturbance from a signal related to the vibration of the machine body using a periodic disturbance observer,
The vibration suppression device, wherein the periodic disturbance suppression calculation means calculates the correction command for canceling the periodic disturbance estimated by the periodic disturbance observer. In the vibration suppression device according to claim 3,
A vibration suppressing device, wherein the main command and the correction command are a current command or a voltage command. 5. A linear motor control device in which the output of the addition means in the vibration suppression device according to any one of claims 1 to 4 is used to control a power converter that supplies AC power to the linear motor. .

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