JPH07110716A - Positioning device - Google Patents

Abstract

PURPOSE:To perform positioning with a high precision by generating an oscillation suppression control torque command based on a motion analysis model and feeding back this torque command to a motor torque command. CONSTITUTION:A machine system 76 generates a bed rotation angular acceleration d<2>phi/dt<2> and a column rotation angular acceleration d<2>gamma/dt<2>. These angular accelerations are converted to a bed acceleration alphab and a column acceleration alphac by an oscillation detector system 77. The bed acceleration alphab and the column acceleration alphac are fetched into an oscillation suppression controller 78. This controller 78 also fetches a position detection value (X1)e of a digital processing system, a time change rate dX1/dt of the position detection value of a machine mobile part, a rotation angle value theta of the motor shaft, and an angular speed detection value (dtheta/dt)e and calculates an oscillation suppression control torque command TV* based on these detection values and outputs this command TV* to a servo system 75, thus reducing the oscillation of a machine system 76.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning device used in an electric discharge machine, a laser machine, a machine tool, etc.
More specifically, the present invention relates to a positioning device that suppresses vibration of a mechanical system.

[0002]

2. Description of the Related Art First, a whole positioning device system will be described. 32 and 33 show, for example, "Mitsubishi EDM V Series Instruction Manual (Mechanical Edition)" (BRN-414).
27, 1990, issued by Mitsubishi Electric Corporation), is an external view of the entire conventional positioning device described on page 8;
32 is a front view thereof, and FIG. 33 is a side view thereof. Figure 3
2 and FIG. 33, 73 is an electrode, 1 is this electrode 73
A head for holding tools such as 2 is a column for supporting the head 1, 9 is a workpiece, 3 is a saddle table for mounting the workpiece 9, 4 is a bed for supporting the saddle table 3 and the column 2, 5 is A leveling bolt that horizontally supports the bed 4, 6 is a servomotor that drives the saddle table 3, 7 is a rotation angle detector attached to the servomotor 6, 21 is a position detector in the Y-axis direction, and 256 is an X-axis. Axis servo motor, 257 is an X axis angle detector, 221 is an X axis position detector, 306 is a Z axis servo motor, 307 is a Z axis angle detector, 314 is a Z axis ball screw, and 321 is Z.
An axis position detector, 8 is a numerical controller for controlling the servo motor 6, the X-axis servo motor 256, and the Z-axis servo motor 306, 345 is an operation panel of the numerical controller 8, and 300 is a display of the numerical controller 8. .

Next, the operation will be described. The head 1 holding a tool such as an electrode is driven in the vertical Z-axis direction by a head-driving Z-axis servomotor 306. The saddle table 3 holding the work is a saddle driving servo motor 6 and a table driving X-axis servo motor 2
56 drives in the X-axis direction and the Y-axis direction in the horizontal plane. Here, the numerical control device 8 uses the angle detectors 7 and 2
57, 307 and the position detectors 21, 221, 321 and other signals are used to obtain an appropriate amount of movement for the servo motors 6, 25.
6,306. According to a command from the control device 8, the relative positions of the tool such as the electrode 73 and the workpiece are positioned in three dimensions in XYZ, and the workpiece 9 is machined into a desired shape. As described above, the entire positioning device includes the mechanical system including the head 1, the column 2, the saddle / table 3, the bed 4, and the leveling bolts 5, and the servo motors 6 and 2.
56, 306, rotation angle detectors 7, 257, 307, position detectors 21, 221, 321, a numerical controller 8, an operation panel 345, and an electric system including a display 300. Hereinafter, conventional techniques relating to the structure of the mechanical system, the control system of the electrical system, the system for matching the mechanical system and the electrical system, and the like will be described.

FIG. 34 is a structural view showing the leveling portion of the conventional positioning device shown in FIGS. 32 and 33. In FIG. 34, 5 is a leveling bolt fitted with an internal thread cut in the bed 4, and 65. Is a nut fitted with the leveling bolt 5, 66 is a pad for holding the leveling bolt 5, and 67 is a floor for holding the pad 66.

Next, the operation will be described. When installing the entire machine, the bed 4 is lifted in advance by a jack or the like. Then, the pad 66 is installed so as to be located approximately below the leveling bolt 5. And
When the bed 4 is gradually lowered, the leveling bolt 5
Is pressed against the pad 66 by the weight of the mechanical structure transmitted from the bed 4. The lower end of the leveling bolt 5 has a spherical shape as shown by the broken line in the figure. Therefore, the lower end of the leveling bolt 5 comes into line contact with the mortar-shaped recess of the pad 66 as shown by the broken line in the figure. The pad 66 horizontally slides on the floor 67 and stands still at a position where this contact portion becomes a circle when viewed from the axial direction of the leveling bolt 5. The leveling bolt 5 is screw-fitted to the bed 4 at its intermediate portion, and is held on the floor via the pad at the lower end. As a result, the bed 4 is maintained at a constant height with respect to the floor surface.

Although the leveling bolt 5 receives sliding resistance from the pad 66, it can be rotated. The rotation of the leveling bolt 5 adjusts the height of the bed 4 from the floor 67. The nut 65 fixes the leveling bolt 5 to the bed 4 and prevents the leveling bolt 5 from rotating. A mechanism similar to the leveling unit shown in FIG. 34 is provided at five points (not shown) of the bed 4. Then, the bed 4 and the entire mechanical structure are horizontally installed by adjusting the leveling bolts 5 at these five positions with respect to the unevenness of the floor 67.

FIG. 35 shows, for example, "Numerical control device, MEL
35 is a system configuration diagram of the positioning device shown on page I-2 of the maintenance manual (BNP-A2938B, issued by Mitsubishi Electric Corporation in 1989) of "DAS, AC servo, MR-S10 series". Is a servo amplifier, 6 is a servo motor driven by a servo amplifier 17, 7 is a rotation angle detector connected to the shaft of the servo motor 6, and 18 is a coupling connected to the shaft end of the servo motor 6. Also, 19 is this coupling 18
A ball screw connected to the axis of the servo motor 6 via
20 is a saddle table 3 driven by this ball screw
A machine moving part corresponding to the head 1 and a position detector 21 installed on the machine moving part 20.

FIG. 36 shows "Numerical control device, MELDA.
S, AC servo, MR-S10 series "specification manual (BNP-B3615B, 1989 issued by Mitsubishi Electric Corporation) block diagram of control system based on control parameters shown on page III-57 to III-58 Is an example. In FIG. 36, 22 is a position command signal, 23 is a position feedback gain multiplier, 24 is a speed command signal,
Reference numeral 25 is a speed feedback gain multiplier, 26 is a phase delay compensator, 27 is a phase lead compensator, 28 is a torque command signal, 29 is a current control system and a servo motor for transmitting this torque command to the rotation speed of the motor shaft, 30 Is a rotation speed detection signal of the motor shaft, 31 is a mechanical system for transmitting the rotation speed of the motor shaft to the position of the mechanical moving portion, 32 is a detection position signal indicating the detection position of the mechanical moving portion, and 33 and 34 are comparators.

Next, the operation will be described. First, the servo amplifier 17 drives the servo motor 6, and at the same time, receives each detection signal from the rotation angle detector 7 and the position detector 21 to perform desired position control. Further, the rotation of the shaft of the servo motor 6 causes the ball screw 19 to rotate via the coupling 18, and the mechanical movable portion 20 moves straight.

The control operation at this time will be described in more detail with reference to FIG. The comparator 33 takes the difference between the position command signal 22 and the detected position signal 32. The position feedback gain multiplier 23 performs proportional amplification of K _p times with respect to the difference to obtain the speed command signal 24. The comparator 34 takes the difference between the speed command signal 24 and the motor shaft rotation speed detection signal 30, and the speed feedback gain multiplier 25 performs a proportional amplification of K _v times the difference. The low frequency region of this amplified signal is further amplified by the phase delay compensator 26 and the phase lead compensator 27 to become the torque command signal 28.

The torque command signal 28 is converted into a motor winding current by a current control system in the servo amplifier. The motor winding current becomes a torque by the servo motor 6 to rotate the motor shaft. The rotation angle detector 7 detects the rotation speed detection signal 30. The rotation of the motor shaft becomes a linear motion of the machine movable part 20 via the ball screw 19 and the like, and the position detector 21 detects the position of the machine movable part and outputs the detected position signal 3
Get 2.

The frequency transfer characteristic of such a positioning control system is schematically shown in FIG. FIG. 37 shows a so-called open-loop transfer characteristic when the feedback loop from the detected position signal 32 of the machine movable part 20 to the comparator 33 is cut off, where the input is the position command signal 22 and the output is the detected position signal of the machine movable part 20. 32. The frequency on the horizontal axis is a dimensionless frequency normalized by the crossover frequency at which the gain of the open loop transfer characteristic is 1, that is, 0 dB.

In order to enhance the speed response of the position control system and the effect of suppressing disturbance, the position feedback gain K _p may be increased. However, when the position feedback gain K _p is increased, the crossover frequency becomes high at the same time, and the resonance frequency approaches the mechanical resonance frequency. For example, in the example shown in FIG.
Since the mechanical resonance R1 is near the dimensionless frequency f of 2 and the mechanical resonance R2 is near the dimensionless frequency f, the gain margin at a frequency where the phase is below −180 degrees is −4 dB,
It can be seen that the control system is unstable. Therefore, in order to stabilize this positioning control system, the position feedback gain K _p must be reduced by 4 dB, that is, 0.63 times.

FIG. 38 shows, for example, Japanese Patent Application Laid-Open No. 55-34716.
It is a block diagram which shows the positioning device shown by the publication. In FIG. 38, 35 is a rotation speed detector attached to the shaft of the servomotor 6, 36 is a speed detector attached to the machine movable part 20, 37 is an output signal of the rotation speed detector 35 and the speed detector 36. A comparator for comparing the output signals, 38 is an amplifier for proportionally amplifying the output of the comparator 37, and 39 is a comparator for comparing the output of the amplifier 38 with the torque command 28. In addition, FIG. 32 and FIG. 3 other than this
3, the same components as those shown in FIGS. 35 and 36 are designated by the same reference numerals, and the duplicate description thereof will be omitted.

Next, the operation of the vibration suppression control system shown in FIG. 38 will be described. The basic positioning operation is the same as the control operation of the control system shown in FIG. That is, based on the position command signal 22 generated by the control device 8A, the rotation angle of the motor shaft detected by the rotation angle detector 7 and the rotation speed of the motor shaft detected by the rotation speed detector 35 are fed back. The mechanical movable unit 20 is moved to a desired position. At this time, in order to suppress destabilization of the control system due to mechanical resonance described with reference to FIG. 37, this conventional example proposes the following vibration suppression control method.

That is, the speed of the machine movable portion 20 is detected by the speed detector 36, and the rotation speed of the motor shaft is detected by the rotation speed detector 35. The difference between them is obtained by the comparator 37. The signal whose difference is amplified by the amplifier 38 is subtracted from the output of the comparator 34 by the comparator 39. In this way, the vibration of the mechanical system that is excited when the amplification factors of the position feedback gain multiplier 23 and the velocity feedback gain multiplier 25 are increased is dealt with.

FIG. 39 is a block diagram showing a positioning device disclosed in Japanese Patent Laid-Open No. 2-158802. In FIG. 39, reference numeral 40 is a basic control unit for performing servo control of position and speed, 41 is a mechanical system to be controlled, and 42 is a vibration suppression controller for compensating the vibration characteristics of the mechanical system. The other components that are the same as those shown in FIG. 36 are designated by the same reference numerals, and their redundant description will be omitted.

Next, the operation will be described. The basic operation for positioning the mechanism system 41 is the same as that shown in FIGS. 36 and 38. That is, the position feedback gain multiplier 23 obtains the speed command signal 24 by multiplying the position command signal 22 minus the detected position signal 32 of the mechanical system by the position feedback gain K _p . Then, the speed feedback gain multiplier 25 obtains a torque command signal 28 to the mechanical system by multiplying the speed command signal 24 by subtracting the derivative of the detected position signal 32 of the mechanical system by the speed feedback gain K _v .

The characteristic of this positioning device is the following vibration suppression control operation. The torque command signal 28 to the mechanical system 41 is input to the vibration suppression controller 42. Vibration suppression controller 42
The values of the modal mass and modal rigidity of the mechanical system 41 are used as the coefficients of the second-order term and the zero-order term of the denominator in the transfer function of. The coefficient of the numerator in the transfer function is determined in consideration of the eigenmode component of the mechanical system 41.
The vibration characteristics of are adjusted.

FIG. 40 is an overall perspective view showing the positioning device disclosed in Japanese Patent Laid-Open No. 2-104489.
1 is a configuration diagram of a transmission mirror system of the positioning device.
In these figures, 43 is a laser oscillator, 44 is a transmission mirror system having a plurality of bend mirrors 47 and transmitting a laser beam 46 oscillated from the laser oscillator 43, 45
Is the laser beam 4 transmitted by the bend mirror 47
A processing head having a condensing lens (not shown) for condensing 6 includes a bending mirror 47 and a processing head 45, and is reciprocated in the Y direction by a Y drive unit having a servo motor 6 and a ball screw 19. Z-axis moving part that moves,
3A is a table that removably holds the workpiece 9 and reciprocates in the X direction by an X drive section having a servomotor and a ball screw (both not shown) like the Y drive section, and 48a is a laser oscillator 43. The vibration detector mounted on the nearest bend mirror 47, 48b is the Z-axis drive unit 1A.
The vibration detectors 48a and 48b attached to the second and subsequent bend mirrors 47 from the laser oscillator 43 incorporated in the vibration detectors detect vibrations in the X and Y directions with respect to the reflecting surface of the bend mirror 47, respectively. Therefore, two pieces are configured as one set.

Reference numeral 48c is a vibration detector which is mounted on the surfaces of the processing head 45 having a horizontal condenser lens 49 which are orthogonal to each other, and which detects vibrations in the X and Y directions with respect to the plane of the condenser lens 49, respectively. Reference numeral 48d is a vibration detector which is mounted on the horizontal planes of the table 3A which are orthogonal to each other and which detects vibrations in the X and Y directions with respect to the horizontal upper surface of the table 3A. Vibration detectors 48a, 48b, 48c, 4
8d is composed of an accelerometer, and the detection signals from these are taken into the numerical controller 8.

Next, the operation will be described. The numerical controller 8 issues a command to drive the X drive unit and the Y drive unit, and moves the table 3A and the Z-axis moving unit 1A by an arbitrary distance in the X and Y directions. It also gives an oscillation command to the laser oscillator 43. The laser beam 46 from the laser oscillator 43 is reflected by the bend mirror 47 of the transmission mirror system 44.
The reflected light is collected by the condensing lens 49 mounted on the processing head 45.
Be transmitted to. The condensing lens 49 condenses on the work 9 held on the table 3A, so that the work 9 is laser-processed into a desired shape. The detection signals from the vibration detectors 48a and 48b mounted on the bend mirror 47, the vibration detector 48c mounted on the processing head 45, and the vibration detector 48d mounted on the table 3A are taken into the numerical controller 8. Each detection signal is converted into a velocity by one integration of the numerical control device 8 and subtracted from the command signal. Then, a command signal considering the detection signal is output to the servo motor 6. In this way, the vibration of the laser beam 46 and the table 3A is suppressed.

FIG. 42 is a block diagram showing a control system of the positioning device disclosed in Japanese Patent Laid-Open No. 1-296301, and FIG. 43 is a motion analysis model thereof. In FIG. 42, 50 is an observer for estimating the state quantity by inputting the torque command signal 28 and the rotation speed detection signal 30 of the motor shaft, 51, 52, 53 are gains for the estimated values X1e, X2e, X3e estimated by the observer. It is a multiplying amplifier.

Further, in FIG. 43, 54 is a rotor of a servo motor, and 55 is an arm of an industrial robot, each of which is a model of inertia. 56 and 57 are springs and dashpots that connect the rotor 54 and the arm 55, and a speed reducer 58 interposed between the rotor 54 and the arm 55.
Is a model of. It should be noted that the same components as those shown in FIG. 39 are denoted by the same reference numerals, and redundant description thereof will be omitted.

Next, the operation will be described. Controlled object 29
The basic operation for positioning is similar to that shown in FIGS. 36 and 38. That is, the position feedback gain multiplier 23 obtains the speed command signal 24 by multiplying the position command signal 22 minus the detected position signal 32 indicating the detected position of the rotor by the position feedback gain K _p . The speed feedback gain multiplier 25 obtains a torque command signal 28 by multiplying the difference between the speed command signal 24 and the rotor rotation speed detection signal 30 by the speed feedback gain. The observer 50 uses the estimated value X1e of the speed of the rotor 54, the estimated value X2e of the speed difference between the rotor 54 and the arm 55, and the estimated value of the displacement difference between the rotor 54 and the arm 55 based on the motion analysis model shown in FIG. Calculate X3e. Further, the disturbance torque such as friction is modeled with its time derivative being zero, and the estimated value X4e of the disturbance torque is calculated. The estimated values X1e, X2e, and X3e are the amplifier 51,
Gains K ₁ , K ₂ and K ₃ are multiplied by 52 and 53 and subtracted from the torque command signal 28. Estimated value X2e, X
The feedback 3e is intended to make one mechanical resonance system caused by the speed reducer 58 act so as to increase damping and rigidity.

FIG. 44 shows, for example, Journal of Precision Engineering, Vol. 57, 9
FIG. 44 is a block diagram showing the dynamic characteristic measuring method of the conventional positioning device shown in page 1647 of the issue No., September 1991, and in FIG. 44, 24A is a control system for applying a drive current to the servomotor 6, 59 Is an accelerometer attached to the mechanical moving part 20, 60 is a charge amplifier for converting an accelerometer signal into a voltage, 62 is a motor current monitor, and 61 is an FFT analyzer for taking in the current monitor signal and the output of the charge amplifier 60. is there. Note that the same parts as those shown in FIGS. 35 and 36 are denoted by the same reference numerals, and duplicate description thereof is omitted.

Next, the operation will be described. Control system 24A
The basic operation in which the motor shaft of the servo motor 6 rotates by the control of and the machine movable portion 20 goes straight through the ball screw 19 is the same as that shown in FIG. At this time, the control system 24A sets a drive current so that the machine movable unit 20 suddenly stops, and causes the servomotor 6 to generate an impulse-like excitation force. The vibration generated by this exciting force is detected by the accelerometer 59 and is transmitted through the charge amplifier 60 to the F
It is taken into the FT analyzer 61. At the same time, the drive current of the servo motor detected by the current monitor 62 is F
The transfer function from the driving current to the acceleration is taken in by the FT analyzer 61, analyzed by the FFT analyzer 61, and the result is output to the plotter 63.

[0028]

Since the conventional positioning device is constructed as described above, the supporting rigidity of the leveling portion of the conventional positioning device shown in FIGS. 32 and 33 cannot be adjusted with respect to the floor 67. There is a problem that the installation rigidity of the machine is affected by the property of the floor 67. Further, there is a problem that it is difficult to reduce and adjust the vibration disturbance transmitted from other machines via the floor 67.

Further, the conventional positioning device shown in FIG. 35 has no means for improving the phase characteristic with respect to the phase delay due to the mechanical resonance of the frequency close to the cross frequency of the position control system. Therefore, the position feedback gain K _p
If is increased, the mechanical resonance causes the control system to become unstable. Therefore, the position feedback gain K _p is limited by the frequency of mechanical resonance, and there is a problem that the quick response of the positioning control system and the disturbance suppression performance are deteriorated.

In the conventional positioning device shown in FIG. 38, since only one amplification factor of the vibration suppression system is set by the amplifier 38, when there are two or more mechanical resonances that affect positioning, both vibrations are suppressed simultaneously. Is difficult. Further, when the frequency of the mechanical resonance approaches within about twice the position control band, the phase delay from the output of the amplifier 38 to the mechanical resonance becomes small and it does not act as damping, so that the vibration cannot be suppressed. There was a problem.

Although the conventional positioning device shown in FIG. 39 tries to utilize the mode parameter, the denominator of the transfer function of the vibration suppression controller 42 has only the second-order term and the zero-order term, which corresponds to damping 1. The next section is not considered. It is indispensable to stabilize the positioning control and add damping to the mechanical system by the velocity feedback multiplier 25 as seen in each conventional positioning device. But,
The vibration suppression control method has a problem that it is not possible to perform feedback in which the characteristics of the mechanical system are sufficiently taken into consideration. Further, if the first-order term of the transfer function denominator corresponding to the damping term is considered in the vibration suppression control system, there is a problem that the control law is difficult to realize because the eigenvector is a complex number. It was

The conventional positioning device shown in FIGS. 40 and 41 is equipped with a large number of vibration detectors, four in the X-axis direction and four in the Y-axis direction, and detects the respective detection signals of the speed and the relative value from the commanded speed. It has a basic configuration of converting to speed and outputting to the servo motor. However, in order to utilize the detection signals of the large number of vibration detectors for suppressing a plurality of mechanical resonances, it is necessary to properly set a total of eight gains of the respective detection signals. There is a problem in that no specific means for setting the gain is provided.
Further, a bend mirror 47 that transmits a laser beam, a processing head 45 that is movable in the Y direction, and a table 3 that is movable in the X direction.
Since a vibration detector is attached to the to detect the vibration of the laser beam transmission system and the mechanical moving part, it is difficult to detect the vibration caused by the elastic deformation of the immovable mechanical structure. Further, since the vibration detector is attached to the movable part of the machine, the vibration detector and its wiring move, which causes problems such as noise of the vibration detector and its wiring, and reduction in reliability regarding durability. .

In the control system of the conventional positioning device shown in FIG. 42, only one mechanical resonance is modeled.
In a positioning device in which a plurality of mechanical resonances are close to the control band, there is a problem in that the estimation error of the vibration of the mechanical system becomes large and it becomes difficult to control the vibration.

Since the conventional positioning device shown in FIG. 44 uses an impulse-like excitation force, the vibration measurement accuracy is lower than that of a sine wave or white noise-like excitation signal. Also,
Since the detection signal of the accelerometer 59 attached to the mechanical system is detected, the measurement of the transfer characteristic of the position feedback signal, which is most closely related to the stability of the control system, becomes indirect and the accuracy of the safety analysis deteriorates. Further, since it is necessary to separately prepare equipment such as the accelerometer 59, the charge amplifier 60, the current monitor 62, and the FFT analyzer 61 and prepare the equipment, there is a problem that it takes time for measurement.

The invention of claim 1 has been made to solve the above problems, and the supporting rigidity of the entire mechanical structure to the floor surface can be easily adjusted, and the influence of mechanical resonance can be reduced at low cost. can, to stabilize the control system for a plurality of mechanical resonance, and allows high gain of the position feedback gain K _p, high speed and high accuracy can be achieved, further, a plurality of mechanical resonance close to the servo control band An object of the present invention is to obtain a positioning device that can suppress the vibration and effectively dampen the mechanical resonance even when the frequency of the mechanical resonance approaches approximately twice the position control band.

It is an object of the present invention to provide a positioning device capable of independently and stably adjusting a plurality of mechanical resonances and greatly increasing the feedback gain.

According to the third aspect of the present invention, a plurality of mechanical resonances can be independently stabilized and adjusted, and the servo gain can be significantly increased to achieve high speed / high speed.
The purpose is to obtain an advanced positioning device.

According to the fourth aspect of the invention, the vibration characteristic of the mechanical system can be directly detected, the vibration can be robustly suppressed against the characteristic change of the mechanical system, and the influence of mechanical resonance in the high frequency range can be obtained by integrating the acceleration signal. The objective is to obtain a positioning device that reduces speed and enhances servo gain to achieve high speed and sophistication.

According to the fifth aspect of the present invention, the operation of the vibration suppression controller can be confirmed on site, and the controller can be set according to the mechanical characteristics, so that a servo gain can be increased to obtain a positioning device with high speed and sophistication. The purpose is to

It is an object of the present invention to provide a positioning device which does not require manual setting of control parameters and is easy to maintain.

It is an object of the invention of claim 7 to obtain a positioning device capable of easily determining a defective portion of a mechanical system.

According to the invention of claim 8, it is possible to obtain a positioning device having a vibration suppression controller which is capable of avoiding the operator's contact with the vibration detector and the signal line of the vibration detector and is excellent in reliability and noise performance. With the goal.

It is an object of the present invention to provide a positioning device that can independently and stably adjust a plurality of mechanical resonances without using a vibration detector, and can greatly enhance the feedback gain.

According to the tenth aspect of the invention, a plurality of mechanical resonances can be independently stabilized and adjusted without using a vibration detector, and the feedback gain can be adjusted without impairing the effect of improving the positioning accuracy by the position detection signal. An object is to obtain a positioning device that can be significantly increased.

According to the eleventh aspect of the present invention, damping can be added to a plurality of machine resonances, the servo gain is increased to achieve high speed and sophistication, and a rotation angle detector for vibration suppression and a rotation angle detection for current command creation are provided. It is an object of the present invention to provide a positioning device which does not require any of the devices and which has high performance at low cost.

It is an object of the invention of claim 12 to obtain a positioning device in which the servo gain of the vertical drive system is also increased to achieve high speed and sophistication.

According to the thirteenth aspect of the present invention, the total state quantity of the mechanical system can be estimated without increasing the number of detectors, vibration can be suppressed at a low cost, and positioning is performed at high speed and sophistication by increasing the servo gain. The purpose is to obtain the device.

According to the fourteenth aspect of the present invention, the servo amplifier operation such as the positioning control can be performed even when the removable card is not provided, and the vibration suppression control is performed when the removable card is mounted. The purpose of the present invention is to obtain a positioning device that can perform vibration suppression control while using a standard servo amplifier, and that can achieve high speed and sophistication at low cost.

According to the fifteenth aspect of the present invention, the vibration energy can be converted into the rigid motion of the entire apparatus regardless of the property of the floor surface, the destabilization of the mechanical resonance can be reduced, and the servo gain can be increased to increase the speed and the sophistication. The purpose of the invention is to obtain a positioning device.

[0050]

According to a first aspect of the present invention, there is provided a positioning device comprising a non-movable part including a bed for supporting an object to be positioned and a column for supporting a tool, and a movable part supported by the non-movable part. A mechanical system, a torque generating means including a servo motor for setting a movable portion at a desired position, a position detector for detecting the position of the movable portion and outputting the detected position, and a rotation angle of a motor shaft of the servo motor. A rotation angle detector that detects and outputs an angle, a speed calculation unit that calculates the time change rate of the detection position from the detection position and an angular velocity from the rotation angle, and a position command signal for instructing the position of the movable unit. ,
And a servo system that creates a motor torque command to the torque generating means from the detected position and angular velocity fed back, a vibration detector that detects acceleration of a non-movable part based on vibration, and a motor torque command. The vibration suppression control torque command to be added to is generated using the outputs of the position detector and the vibration detector based on the motion analysis model of the mechanical system.

The positioning device according to a second aspect of the present invention is the positioning device according to the first aspect, wherein the motion analysis model uses one rotary spring and one rotary dashpot for elastic bending deformation of the bed and the column. And the drive side and the driven side of the ball screw are connected by one translation spring and one translation dashpot relating to elastic deformation of the ball screw connected to the motor shaft of the servomotor, By one rotary spring and one rotary dashpot relating to elastic deformation of the leveling part for adjusting the height from the floor of the vehicle, or one rotary spring, one translation spring, one rotary dashpot And a model of a system in which a bed and a floor are connected by one translation dashpot, in which the vibration suppression controller outputs the rotation angle detector and the rotation angle detector. Vibration suppression control torque using the detected position and its time change rate calculated based on the motion analysis model from the output and the output of the position detector, and the rotation angle and angular acceleration of the non-movable part calculated from the output of the vibration detector. It is configured to generate a command.

The positioning device according to a third aspect of the present invention is the positioning device according to the first aspect, wherein the motion analysis model uses one rotary spring and one rotary dashpot for elastic bending deformation of the bed and the column. And the drive side and the driven side of the ball screw are connected by one translation spring and one translation dashpot relating to elastic deformation of the ball screw connected to the motor shaft of the servomotor, By one rotary spring and one rotary dashpot relating to elastic deformation of the leveling part for adjusting the height from the floor of the vehicle, or one rotary spring, one translation spring, one rotary dashpot And a model in which the bed and the floor are connected by one translation dashpot, and the vibration suppression controller uses the state equation based on the motion analysis model. The that condition quantity, is intended to include means for generating a vibration suppression control torque command using the signal mode matrix is converted to a mode coordinate to real.

A positioning device according to a fourth aspect of the present invention is the positioning device according to the first aspect, in which the vibration suppression controller integrates the output signal of the vibration detector to obtain the speed of the non-movable part, and the integral element. And an integral element for integrating the speed to obtain the position of the non-movable part, and integrating the output signal of the vibration detector using the output of each integral element to generate a vibration suppression control torque command. .

A positioning device according to a fifth aspect of the present invention is the positioning device according to the first aspect, wherein a plurality of expected mechanical vibration frequencies and vibration modes of the mechanical system are displayed on the display unit,
The control device further includes a control device that determines a vibration suppression control gain used when generating the vibration suppression control torque command according to a designation input according to the display and supplies the vibration suppression control gain to the vibration suppression controller.

According to a sixth aspect of the present invention, there is provided the positioning device according to the first aspect, wherein the torque generating means is vibrated to vibrate the mechanical system, and the mechanical system is output from the position detector and the rotation angle detector. The vibration suppression control gain used to generate the vibration suppression control torque command based on the estimation result, and supplies the vibration suppression control gain to the vibration suppression controller. It is a thing.

A positioning device according to a seventh aspect of the present invention is the positioning device according to the sixth aspect, wherein the control device includes means for determining an abnormal portion of the mechanical system based on the estimated natural frequency.

A positioning device according to an eighth aspect of the present invention is the positioning device according to any one of the first to seventh aspects, wherein the vibration detector and the cable from the vibration detector to the vibration suppression controller are It is installed inside the non-movable part.

According to a ninth aspect of the present invention, there is provided a positioning device, wherein the relative position of the detected position of the movable part from the motor shaft rotation angle,
A vibration suppression controller that calculates the relative speed of the detected position of the movable part with respect to the motor shaft angular speed and uses them to generate a vibration suppression control torque command to be added to the motor torque command is provided.

A positioning device according to the invention of claim 10 is
In order to remove the low frequency component of the signal representing the vibration suppression control torque command generated by the vibration suppression controller, the breaker frequency is included in the filter means so as to be lower than the frequency band in which the vibration is to be suppressed.

A positioning device according to the invention of claim 11 is
The positioning device according to any one of claims 1 to 10, wherein the servo motor is an AC motor, and the torque generating means includes the AC servo motor and a rotation angle detector provided for positioning. And a current controller that generates a current command to the AC servomotor using the angle.

A positioning device according to the invention of claim 12 is
A mechanical system having a non-movable part including a column that supports the object to be positioned and a column that supports the tool and a movable part supported by the non-movable part, and a head that moves in the vertical direction toward the object to be positioned, A vertical torque generator that includes a vertical servo motor that drives the head and sets the head to a desired position, a torque generator that includes the servo motor to set the movable portion to a desired position, and detects the position of the movable portion. Position detector that outputs the detected position by using the rotation angle detector, a rotation angle detector that detects the rotation angle of the motor shaft of the servo motor and outputs the angle, a time change rate of the detection position from the detection position, and the angular velocity from the rotation angle. And a servo system that creates a motor torque command to the torque generating means using the position command signal for indicating the position of the movable part, the detected position and the angular velocity. In the device, the relative position from the rotation angle of the detection position, and the relative speed with respect to the angular velocity of the detection position, using a vibration suppression controller that generates a vibration suppression control torque command to be added to the motor torque command, A vertical vibration suppression controller that uses the relative position and the relative speed to generate a vibration suppression control torque command that is added to the vertical motor torque command to the vertical torque generation means.

A positioning device according to the invention of claim 13 is
The vibration suppression control torque command is added to the motor torque command by estimating the position and speed of the non-movable part using the observer based on the mechanical analysis model of the mechanical system, and using the output of the position detector and the estimation result by the observer. Is provided with a vibration suppression controller.

The positioning device according to the invention of claim 14 is
In the positioning device according to claim 1, claim 9, claim 10 or claim 13, the vibration suppression controller is housed in a card that is attachable to and detachable from the main body.

The positioning device according to the invention of claim 15 is
A mechanical system having a non-movable part including a column supporting a bed and a tool for supporting an object to be positioned and a movable part supported by the non-movable part, and a leveling bolt for adjusting the height of the bed from the floor, Torque generating means including the servo motor for setting the movable part to a desired position, a position detector for detecting the position of the movable part and outputting the detected position, and a rotation angle of the motor shaft of the servo motor for detecting the angle. A rotation angle detector that outputs, a speed calculation unit that calculates the time change rate of the detection position from the detection position and an angular velocity from the rotation angle, a position command signal for instructing the position of the movable unit, the detection position and the angular velocity. And a servo system for generating a motor torque command to the torque generating means by using a leveling bolt fitted to the bed via a spacer at a position higher than the bottom surface of the bed. Those that are configured to be.

[0065]

The vibration suppression controller in the inventions of claims 1 and 2 creates a vibration suppression control torque command based on a motion analysis model in which each resonance of the mechanical structure is taken into consideration, and uses the torque command as a motor torque command. It returns to enable high-precision positioning.

In the vibration suppression controller according to the third aspect of the present invention, the block diagonalization mode separation is performed on the control target whose eigenmode is a complex number in the usual eigenvalue analysis to obtain a real eigenvector, and based on the eigenvector, Control multiple mechanical resonances independently.

In the vibration suppression controller according to the invention of claim 4, the output signal of the vibration detector is passed through the integrating element to obtain the position and speed due to the vibration of the non-moving part, and the position signal is obtained by reducing the gain in the high frequency range. And get the speed signal.

In the control device according to the invention of claim 5, the vibration characteristics of the mechanical structure are displayed on the display section for each mode, and the setting of the control parameter for each mechanical resonance is facilitated.

In the control device according to the invention of claim 6, for example, the detection signals of the position detector and the rotation angle detector of the non-moving part during vibration and the motor drive current are fetched and recorded for a certain period of time. The recorded data is the natural frequency of the mechanical system,
It is possible to estimate the damping ratio, the eigenmode, etc., display the vibration characteristics of the mechanical structure for each mode on, for example, a display, and adjust the control parameter for each mechanical resonance.

The control device according to the invention of claim 7 makes it possible to specify the part of the mechanical system relating to the abnormal natural vibration.

The vibration detector and the wiring thereof according to the invention of claim 8 are mounted, for example, inside a box-shaped mechanical structure,
Improves noise resistance and durability.

The vibration suppression controller according to the invention of claim 9 calculates the relative position of the detected position of the movable part from the motor shaft rotation angle and the relative speed of the detected position of the movable part with respect to the angular velocity of the motor shaft to detect vibration. No need for vessels.

According to the tenth aspect of the invention, the filter means removes the low frequency component of the signal representing the vibration suppression control torque command generated by the vibration suppression controller. Since the static positioning accuracy of the movable part depends on the low-frequency component, removing it improves the positioning accuracy.

The output signal of the rotation angle detector of the motor shaft according to the eleventh aspect of the present invention is used in the rectification processing system of the winding current of the AC servomotor, and in the relative displacement detection system of the mechanical moving part and the motor shaft. Is also used at the same time to realize vibration suppression control at low cost without adding a new sensor for vibration suppression.

According to the twelfth aspect of the invention, the position detector of the horizontal drive system and the rotation angle detector of the horizontal drive motor detect mechanical resonance caused by bed bending caused by vertical drive, and suppress vertical vibration. Based on this, the controller and the vertical torque generation means give the bed a torque that stabilizes the bed bending mechanical resonance, thereby enabling vibration suppression control at low cost without adding a new sensor in the vertical drive system. To be realized.

The vibration suppression controller in the invention of claim 13 estimates the state quantity of the mechanical system without a sensor by an observer based on a motion analysis model covering the resonance of the mechanical structure, and uses this state quantity to perform the vibration suppression control. Is executed.

In the portion for realizing the vibration suppression controller and the servo system in the invention of claim 14, the portion for realizing the vibration suppression controller is a separate card, and a general-purpose servo system is made common by the add-on of this card. It is possible to attach and detach the vibration suppression control according to each mechanical system as it is.

According to the fifteenth aspect of the invention, the leveling portion can be adjusted in height so as to keep the bed horizontal with respect to the unevenness of the floor, and the supporting rigidity from the floor to the bed can be adjusted, so that the property of the floor and the target can be obtained. The position control system is stabilized by adjusting the phase delay and frequency of the mechanical resonance according to the control bandwidth.

[0079]

【Example】

Example 1. Embodiments of the present invention will be described below with reference to the drawings. 1 is a block diagram showing a configuration of a positioning device according to a first embodiment of the present invention. 75 is a servo system for controlling the servo motor 6, 76 is a mechanical system controlled by the servo system 75, and 77 is a mechanical system. Is a vibration detector system for detecting the vibration of the mechanical system 76, 78 is a torque command signal T _m from the servo system 75, the detected angle θ of the motor shaft of the servomotor 6 from the mechanical system 76, and the mechanical system 76. It is a vibration suppression controller that performs vibration suppression control based on a position detection value x _{l of} a machine movable part and a signal of a vibration detector system. The appearance of the positioning device according to this embodiment is similar to that of the conventional device shown in FIGS. 32 and 33. The installation situation of the position detector 21 in the positioning device is the same as the conventional one shown in FIG.

The servo amplifier 17 is realized by, for example, a digital signal processor, and the servo system 75 and the vibration suppression controller 78 of FIG. 1 are mounted on the processor of the servo amplifier 17.

As shown in FIG. 1, in the servo system 75, 79 is a 0th-order holder of a circuit for processing the position detection value x _l , 133 is a 0th-order holder of a circuit for processing the angular velocity detection value dθ / dt, and 80 is a A dead time element of the position loop digital operation processing, 134 is a dead time element of the speed loop digital operation processing, and ( _xl ) _e is a dead time element 80 of the position loop digital operation processing. Position detection value of (dθ / dt) _e
Is a dead time element 13 of the digital arithmetic processing of the speed loop.
The angular velocity detection value of the motor shaft in the digital processing system after 4 is shown.

T _ms ^* is the servo torque command generated in the position loop and velocity loop, and T _m ^* is the servo torque command T _ms ^* and the vibration suppression control torque command T _v ^* output from the vibration suppression controller 78. The motor torque command given by the sum is shown. Reference numeral 196 is a torque generating means for generating torque according to the motor torque command T _m ^* . T _m represents the motor torque generated by the torque generating means 196.

FIG. 1 shows a model of the x-direction control system including the mechanical system 76, and the output amount of each block shows the physical amount output from each system. A control system in the y direction can be modeled similarly, and the y direction can be similarly controlled by the control method described below.

In the actual positioning device, the servo system 75
Corresponds to a part of the servo amplifier 17 (position loop, velocity loop, a part for calculating the angular velocity detection value (dθ / dt) _e , and a part for fetching the position detection value ( _xl ) _e ) and the servo motor 6. The torque generating means 196 corresponds to the current amplifier of the servo amplifier 17 and the servo motor 6.
The mechanical system 76 includes a mechanical movable part, a non-movable part, a position detector, a rotation angle detector, and a part of the servo amplifier 17 (the angular velocity detection value dθ / dt and the time change rate dx _l / d of the position detection value.
(a part for calculating t). The vibration detector system 77 is
It corresponds to a vibration detector such as an accelerometer and a part of the servo amplifier 17 (a part for capturing the output of the vibration detector).

Further, as shown in FIG. 35, the position detector 2
1 and the like are attached to the machine movable portion 20, and the rotation angle detector 7 of the motor shaft and the like are attached to the servo motor 6.
Therefore, in the actual positioning device, the position detector 21
The position detection value x _l of the machine movable portion 20 is supplied to the portion of the servo amplifier 17 which realizes the servo system 75. The rotation angle detector 7 supplies the rotation angle θ of the motor shaft of the servo motor 6 to the portion of the servo amplifier 17 that realizes the vibration suppression controller 78.

Further, the servo amplifier 17 includes the position detector 2
From the position detection value x _l of the machine movable part 20 detected in ₁ ,
The time change rate of the position detection value dx ₁ / dt (dx ₁ / dt is a physical quantity of the mechanical system 76, so in reality, (dx ₁ / d)
t) is recognized as _e . ) Is calculated. In FIG. 1, the time of position detection value of the mechanical system 76 the rate of change dx _l /
dt have been shown to be recognized as a servo system 75 in (dx _l / dt) _e.

The servo amplifier 17 calculates the rotation angular velocity dθ from the rotation angle θ of the motor shaft detected by the rotation angle detector 7.
/ Dt (dθ / dt is a physical quantity of the mechanical system 76,
Actually, it is recognized as (dθ / dt) _e . ) Is calculated.

FIG. 2 is a block diagram of the mechanical system 76 shown in FIG. That is, the behavior of the mechanical system 76 by the head 1, column 2, saddle table 3, bed 4 and leveling bolt 5 shown in FIG. 32 is modeled and shown. Reference numerals 81, 82, 83, and 84 are components of the mechanical system 76, and respectively indicate a motor shaft system of a servomotor, a ball screw system, a leveling system, and a bed bending system.
Indicates a position detection system mounted on the mechanical system 76. The position detection system 85 includes the position detector 21 mounted on the machine movable unit 20.
Corresponding to. In the motor shaft system 81, 86 is a coefficient element which is the reciprocal of the inertia moment J of the motor shaft, and 87 is an integrator.

In this model, the bed 4 and the column 2 are connected by one rotary spring and one rotary dashpot for elastic bending deformation of the bed, and one translation spring and one translation spring for elastic deformation of the ball screw are used. The driving side and the driven side of the ball screw are connected to each other by one translation dash pot, and one rotation spring and one rotation dash pot related to the leveling portion or one rotation spring, one translation Spring, 1 rotating dashpot and 1
This is based on a motion analysis model configured by connecting the bed 4 and the installation floor by means of individual translation dashpots.

In the ball screw system 82, 89 is a coefficient element related to the lead conversion coefficient of the ball screw 19, and 90 is a coefficient element related to the constant J _t / Jm _s related to the mass of the mechanical movable portion 20 in the ball screw system 82. However, J _t = J + m _s L ² / 4π ² .

Dx _n / dt represents the amount of elastic deformation of the ball screw 19 over time, and x _n represents the amount of elastic deformation of the ball screw. 93 coefficient elements for the spring constant k _n of the ball screw 19, 94 is the coefficient elements for damping constant c _n of the ball screw, 95 is a coefficient element on the distance h _b from the rotational center of the bed 4 to the ball screw 19, 96 is a column 2 is a coefficient element related to the distance h _n from the center of rotation to the ball screw 19.

In the leveling system 83, 97 is a constant a ₁ relating to the moment to the bed 4 generated by the elastic deformation amount x _n of the ball screw, that is, (I _g h _b + I _pg h)
_n ) k _n (where I _g and I _pg are moments of inertia about the column and bed), 98 is dx _n / d
constant a ₁ i.e. about moment in the bed 4 caused by the _{t (I g h b + I} pg h n) coefficient elements for c _n, 99 is the moment of inertia I about the bed and the column
_d is a coefficient element related to the reciprocal of I _p I _g −I _pg ² .

Dφ / dt represents the bed rotation angular velocity of the bed 4, and φ represents the bed rotation angle of the bed 4. 102 is a constant a ₃ relating to the moment to the bed 4 generated by the bed rotation angle φ, that is, (k _l + k _b + k _n h _b ²
+ K _c h _ls ² ) I _g + (k _b −k _c h _ls h _kc + k _n h _n
h _b ) Coefficient element for I _pg (where k _l is the rotational spring constant around the leveling bolt 5, k _b is the spring constant for the bending deformation of the bed 4, k _c is the spring constant of the leveling bolt 5 below the column 3, h _ls is a constant related to the geometrical relationship between k _b and k _l, and h _kc is a constant related to the geometrical relationship between k _c and k _b ).

103 is a constant a ₄ relating to the moment to the bed 4 caused by the bed rotation angular velocity dφ / dt, that is, (c _l + c _b + c _n h _b ² + c _c h _ls ² ) I _g +
_{(C b -c c h ls h} kc + c n h n h b) I pg relates coefficient elements (where c _l is the rotational damping constant around the leveling bolts 5, c _b the attenuation constant for the bending deformation of the bed 4, c _c Is a damping constant of the leveling bolt 5 below the column 3, h _ls is a constant relating to the geometrical relationship between c _c and c _l , h
_kc is a constant related to the geometrical relationship between c _c and c _b )
Is.

In the bed bending system 84, 104 is a constant a ₇ relating to the moment to the column 2 generated by the elastic deformation amount x _n of the ball screw, that is, (I _p h _n + I _pg h).
_b) k _n coefficients for elements (where I _p is the moment of inertia about the bed), the coefficient relating dx _n / constants a ₈ i.e. about moment in the column 2 caused by _{dt (I p h n + I} pg h b) c n is 105 Is an element.

In the leveling system 83, 106 is a constant a ₉ relating to the moment to the column 2 generated by the bed rotation angle φ, that is, (k _b −k _c h _ls h _kc + k _n h).
_n h _b ) I _p + (k _n h _b ² + k _l + k _b + k _c h _ls ² )
Coefficient element relating to I _pg , 107 is bed rotation angular velocity dφ
Constant a ₁₀ relating to the moment to column 2 caused by / dt, that is, (c _b −c _c h _ls h _kc + c _n h _n h
_b ) I _p + (c _n h _b ² + c _l + c _b + c _c h _ls ² ) I _pg
Is a coefficient element related to.

In the bed bending system 84, γ is column 2
Column rotation angle with respect to bed 4, dγ / dt is
Column rotation angular velocity of bed 2 with respect to bed 4, 110 is
Moment to column 2 caused by ram rotation angle γ
Constant a for₁₁That is (k_b + K_c + H_kc ² + K_n 
h_n ²) I_p + (K_b -K_kch_ls+ K_n h_n h_b ) I_pgTo
It is a coefficient element related to. 111 is the column rotation angular velocity dγ
The moment to column 2 caused by / dt
Constant a₁₂That is (c_b + C_c h_kc ² + C_n h _n ²) I_p 
+ (C_b -C_c h_kch_ls+ C_n h_n h_b ) I_pgRegarding
The coefficient element, 112 is generated by the column rotation angle γ109.
Constant a relating to moment to bed 4_Five Ie
(K_b -K_c h_lsh_kc+ K_n h_n h_b ) I_g + (K_b +
k_c h_kc ² + K_n h_n ²) I_pgCoefficient element for, 113
Is the bed 4 generated by the column rotation angular velocity dγ / dt
Constant a for the moment to₆ That is (c_b -C_c 
h_lsh_kc+ C_n h_n h_b ) I_g + (C_b + C_c h_kc ² +
c_n h_n ²) I_pgThere is a coefficient element for.

In the position detection system 85, 114 is a coefficient element related to the constant h _bl related to the geometrical relationship between the bed 4 and the position detector 21, and 115 is a constant h related to the geometrical relationship between the column 2 and the position detector 21. It is a coefficient element related to _cs . d ² φ / dt ² indicates the bed angular acceleration that is the rotational angular acceleration of the bed 4, and d ² γ / dt ² indicates the column angular acceleration that is the rotational angular acceleration of the column 2 with respect to the bed 4.

FIG. 3 is a block diagram showing the contents of the vibration detection system 77. In the figure, 118 is a coefficient element for the bed vibration detector position coefficient h _1sa which is a constant relating to the geometrical relationship of the bed vibration detector 136 mounted on the bed 4, and 120 is an A-D conversion of the output of the coefficient element 118. A to D converter 119 is a coefficient element for the column vibration detector position coefficient h _btc , which is a constant relating to the geometrical relationship of the column vibration detector 137 mounted on the column 2.
Reference numeral 21 is an AD converter for AD converting the output of the coefficient element 119. α _b is the bed acceleration that is the digitized acceleration detected by the bed vibration detector 136 mounted on the bed 4, and α _c is the acceleration detected by the column vibration detector 137 mounted on the column 2. The column acceleration, which is digitized, is shown. That is, the bed vibration detector 136 and the column vibration detector 137 are
Corresponding to an actual vibration detector, the AD converters 120, 12
Reference numeral 1 corresponds to an AD converter in the servo amplifier 17.

FIG. 4 is a block diagram showing the contents of the vibration suppression controller 78. In the figure, 150 is a 0th-order holder of the angle detection signal processing system, 151 is a dead time element of the digital arithmetic processing of the angle processing system in the position loop, and 15
2 is a 0th-order holder of the time differential processing system of the position detection signal, 1
53 is a dead time element of the position differential signal system in the speed loop, 154 is a zero-order holder of the detection processing system of the bed acceleration α _b , 155 is a dead time element of the acceleration α _b processing system in the speed loop, and 156 is a column acceleration α _c. 0th-order holder of the detection processing system of 157 is the acceleration α in the velocity loop.
_{c This} is a dead time element of the processing system.

Further, θ _e is the detected angle value of the digital processing system after the dead time element 151 of the digital calculation processing of the angle processing system in the position loop, and (dx ₁ / dt) _e is the position differential signal processing system of the velocity loop. Dead time element 1
The position differential detection value of the digital processing system after 53, (α
_b ) _e is the bed acceleration detection value of the digital processing system that has passed through the dead time element 155 of the acceleration processing system in the speed loop, and (α _c ) _e is the digital processing system that has passed through the dead time element 157 of the acceleration α _c processing system in the speed loop. Column acceleration detection value of 122, 122 is an integrator (integral element) that receives the bed acceleration detection value (α _b ) _e of the digital processing system as an input,
v _b is the bed speed which is the output of this integrator 122, 12
4 is an integrator (integral element) that receives the bed velocity v _b , x _b is the bed position that is the output of the integrator 124, and 126 is the column acceleration detection value (α _c ) _e of the digital processing system. integrator (integrating element), v _c is the output of the integrator 126 column speed of an integrator (integrating element) which receives the column velocity v _c is 128, x _c
Is the column position which is the output of this integrator 128.

Further, 130 is a coefficient element related to the reciprocal of the bed vibration detector position coefficient h _lsa , 131 is a coefficient element related to the reciprocal of the column vibration detector position coefficient h _btc , φ _e is a detected value of the bed rotation angle, and (dφ / dt) _e is the detected value of the bed rotation angular velocity, 148 is the detected value of the column rotation angle γ
_e , (dγ / dt) _e is the detected value of the column rotation angular velocity, 1
58, 159, 160, 161, 162, 163, 16
4, 165 are vibration suppression gains. As mentioned above,
The vibration suppression controller 78 is realized by the processor of the servo amplifier 17.

Next, the operation will be described. The basic operation of the servo system 75 shown in FIG. 1 is similar to that of the conventional example. In other words, a position command x sent from the numerical control device (control device) 8 for instructing the position to be moved of the machine movable part.
Subtract the position detection value ( _xl ) _e from _l ^* . This difference is multiplied by the feedback gain K _p to give the speed command (dθ / dt)
^{Produces *} . The angular velocity detection value (dθ / dt) _e is subtracted from the velocity command (dθ / dt) ^* , and the difference is multiplied by the velocity feedback gain K _v to obtain the servo torque command T _ms.
^{Produces *} .

At this time, since the servo system 75 is mounted as a digital processing system on the digital signal processor in the servo amplifier 17 shown in FIG. 35, the position detection value zero-order holder 79 and the angular velocity detection value zero-order are provided. A phase delay occurs due to the calculation time of the position control system indicated by the holder 133 and the dead time element 80 and the calculation time of the speed control system indicated by the dead time element 134. This phase delay affects the position detection value x ₁ and the angular velocity detection value dθ / dt. That is, in reality, the position detection value (x
Feedback control is performed by _l ) _e and the angular velocity detection value (dθ / dt) _e .

The servo torque command T _ms ^* from the speed feedback gain multiplier 25 and the vibration suppression control torque command T _v ^* from the vibration suppression controller 78 are added to generate a motor torque command T _m ^* . The torque generating means 196
The motor torque T _m is generated according to the motor torque command T _m ^* , and the mechanical system 76 is driven.

The mechanical system 76 has a bed rotation angular acceleration d ² φ.
/ Dt ² and column rotation angular acceleration d ² γ / dt ² . These angular accelerations are converted into a bed acceleration α _b and a column acceleration α _c by the vibration detector system 77. Then, the bed acceleration α _b and the column acceleration α _c are taken into the vibration suppression controller 78. The vibration suppression controller 78
Position detection value ( _xl ) _{e of the} digital processing system (that is,
(The output of the position detector 21 is processed by the servo amplifier 17), the time change rate dx _l / dt of the position detection value of the machine movable part 20, the rotation angle value θ of the motor shaft, and the angular velocity detection value (dθ / dt). _e (that is, the output of the rotation angle detector 7 processed by the servo amplifier 17) is also taken in at the same time, the vibration suppression control torque command T _v ^* is calculated based on these detected values, and this vibration suppression control torque command T
_{The v} ^* is output to the servo system 75 to reduce the vibration of the mechanical system 76.

Inside the vibration suppression controller 78, d
The x ₁ / dt is treated as the time change rate (dx ₁ / dt) _e calculated by the servo amplifier 17 based on the output of the position detector 21. θ is treated as the rotation angle value θ _e after the processing for taking in is performed.

Motor shaft system 81 of mechanical system 76 shown in FIG.
Inputs the torque obtained by subtracting the mechanical system load torque T ₁ from the motor torque T _m from the servo system 75. The torque is multiplied by the reciprocal of the inertia moment J by the coefficient element 86 to obtain the rotational angular acceleration of the motor shaft. Then, the output of the coefficient element 86 is integrated by the integrator 87 and becomes the rotational angular velocity dθ / dt of the motor shaft. Rotational angular velocity dθ
/ Dt becomes the rotation angle θ of the motor shaft through another integrator 87.

Since the operations of the ball screw system 8, the leveling system 83, and the bed bending system 84 shown in FIG. 2 are mechanical, their operations will be described with reference to the mechanical model of the mechanical system shown in FIG. In FIG. 5, k _n and k _c are translational springs, k,
k _b indicates a rotary spring. Also, the rotation spring k _b is
The rotary spring and the rotary dashpot may be replaced, and the translation spring k _c may be replaced by the translation spring and the translation dashpot.

In the ball screw system 82, the motor torque T _m is multiplied by the lead conversion coefficient by the conversion coefficient element 89 of the lead and becomes the thrust of the ball screw 19 in the axial direction.
Since taking a positive direction of the elastic deformation amount x _n of the rotation angle θ and the ball screw of the motor shaft in the direction as shown in FIG. 5, the output of the coefficient of the read conversion element 89, the elastic deformation amount x _n of the ball screw The servo motor 6 acts in the negative direction. At the same time, the nut 1 combined with the ball screw 19
93 and the support mounting reaction force 190 that contributes to the elastic deformation amount x _n of the ball screw from the bed mounting portion 194 side of the nut 193.
Is added. A force obtained by subtracting the output of the lead-converted coefficient element 89 from the support system reaction force 190 is multiplied by the constant J _t / J _ms regarding the mass by the coefficient element 90. The output of the coefficient element 90 becomes the time variation dx _n / dt of the elastic deformation of the ball screw 19 via the integrator 87. Further, the amount of elastic deformation of the ball screw becomes x _n via the integrator 87. The elastic deformation amount x _n of the ball screw is the ball screw spring constant k _n.
It becomes a part of the support system reaction force 190 via the coefficient element 93 which is multiplied by.

On the other hand, the bed mounting portion 194 of the nut 193
Is displaced by rocking the bed 4. Therefore, bed rotation angular velocity d.phi / dt is through the coefficient element 94 about the attenuation constant c _n coefficient element 95 and the ball screw on the distance h _b from the rotational center of the bed 4 to the ball screw 19, the bed rotation angle φ is geometrically Constant h _b 95 and ball screw spring constant k
It becomes a part of the support system reaction force 190 via the coefficient element 93 related to _n .

Also, the bed mounting portion 194 of the nut 193.
Although not shown in FIG. 3 for the sake of simplicity, it is also displaced by column rotation due to deformation of the bed 4. Therefore, column rotation angular velocity d [gamma] / dt is through the coefficient element 94 about the attenuation constant c _n coefficient element 96 and the ball screw on the distance h _n from the rotation center of the column 2 to the ball screw 19, the column rotation angle gamma, It becomes a part of the support system reaction force 190 via the coefficient element 96 and the coefficient element 93 relating to the spring constant k _n of the ball screw 19.

With respect to the leveling system 83 shown in FIG. 2, the driving force of the servo motor 6 is the ball screw elastic deformation speed dx.
_It acts as a moment via _n / dt, the constant a ₁ , the elastic deformation amount x _n of the ball screw and the constant a ₂ . Therefore,
As the bed 4 swings, the bed rotation angular velocity dφ
/ Dt and the bed rotation angle φ occur. The bed rotation speed dφ / dt and the bed rotation angle φ include the rotation damping constant c _l around the leveling bolt 5, the rotation spring constant k _l , the damping constant c _c of the leveling bolt 5 below the column 2 and the spring constant k _c . The swing moment of the bed 4 is obtained via the constants a ₄ and a ₃ . Further, the column rotation angular velocity dγ / dt and the column rotation angle γ are swinging moments with respect to the bed 4 via the constants a ₆ and a ₅ including the damping constant c _b of the bed bending and the spring constant k _b .

For the bed bending system 84 shown in FIG. 2, the driving force of the servomotor 6 is the elastic deformation amount x _{n of} the ball screw, a constant a ₇ , and the time change amount dx _n / dt of the ball screw elastic deformation.
And acts as a moment via the constant a ₈ . Therefore, due to the bending deformation of the bed 4, the column rotation angle γ and the column rotation angular velocity dγ / dt are generated.
The column rotation angle γ and the column rotation angular velocity dγ / dt are
It becomes a bending moment with respect to the bed 4 via the constants a ₁₂ and a ₁₁ including the damping constant c _b of the bed bending and the spring constant k _b . Also, the bed rotation angle φ and the bed rotation angular velocity dφ
/ Dt is a bed bending damping constant c _b and a spring constant k _b
It becomes a bending moment with respect to the bed 4 via constants a ₉ and a ₁₀ including

The position detection system 85 shown in FIG. 2 is a block diagram showing the dynamic characteristics of a linear encoder (not shown) in which the movable portion is mounted on the saddle table 3 and the fixed portion is mounted on the bed 4. That is, the position detection system 85 determines that the bed 4 is set at the bed rotation angle φ from the moving amount of the linear encoder on the movable part side, which is obtained by adding the lead conversion value of the rotation angle θ of the motor shaft and the elastic variable amount x _n of the ball screw. the difference or the linear encoder of the value obtained by multiplying the constant h _bl value and a column rotation angle multiplied by γ about the geometric relationships constants h _cs about geometric relationship of the column 2 and the position detector 21 of the position detector 21 The value x _l obtained by subtracting the movement amount on the fixed part side is detected.

As described above, the mechanical system 76 includes the ball screw system 8
2, a leveling system 83, and a bed bending system 84. When the mechanical system 76 is driven by the servo system 75 shown in FIG. 1, since the driving force of the servo motor 6 is transmitted to these three vibration systems, three mechanical resonances are excited as shown in FIG. become. Then, when the position feedback gain K _p is increased, the mechanical resonance R1 and the mechanical resonance R2 become unstable, and the upper limit of the control performance is limited, as described in the description of the related art.

In this embodiment, the vibration detector system 77 is mounted on the mechanical system 76 to suppress mechanical resonance. And
The vibration suppression controller 78 processes the signals from the vibration detector system 77 and the position detection system 85 to perform vibration suppression control.

The vibration detector system 77 shown in FIG. 3 is a block diagram showing the dynamic characteristics of the vibration detector mounted on the mechanical system 76. Bed vibration detector 136 and AD
The converter 120 outputs a bed acceleration α _b obtained by A / D converting a product _obtained by multiplying the bed rotation angular velocity d ² φ / dt ² by the bed vibration detector position coefficient h _1sa by the coefficient element 118. The column vibration detector 137A-D converter 121 _adds a value _obtained by multiplying the column rotation angular acceleration d ² γ / dt ² by the column vibration detector position coefficient h _btc by the coefficient element 119 to the analog value of the bed acceleration α _b. , The column acceleration α _c obtained by A / D converting the added value is output.

The vibration suppression controller 78 shown in FIG. 4 first latches the bed acceleration α _b and the column acceleration α _c , which are the outputs of the vibration detector system, and takes them in the digital processing system on the servo amplifier. Then, the bed acceleration α _b is 0
The bed acceleration detection value (α _b ) _e is passed through the next holder 154 and the dead time element 155. Also, the column acceleration α
_c becomes a column acceleration detection value (α _c ) _e after passing through the 0th-order holder 156 and the dead time element 157. The bed acceleration detection value (α _b ) _e is integrated by the integrator 122 and becomes the bed acceleration detection value v _b . Column acceleration detection value (α
_c ) _e is integrated by the integrator 126 and becomes the column speed detection value v _c . Furthermore, integrator 124 and integrator 128
And, the bed position x _b and the column position x _c are obtained. Here, the integrators 122, 124, 126, 128
Is a first-order low-pass filter, and is designed so that its output is less likely to be saturated even when a DC drift is superimposed on the acceleration detection values (α _b ) _e and (α _c ) _e .

For the bed position x _b and the bed speed v _b ,
Each of _them is multiplied by a geometric constant (the reciprocal 1 / h _{1sa of the} bed vibration detector position coefficient) by the coefficient element 130,
The bed rotation angle detection value φ _e and the bed rotation angular velocity detection value (dφ / dt) _e are obtained. The column position x _c and the column velocity v _c are respectively multiplied by a geometric constant (the reciprocal 1 / h _btc of the column vibration detector position coefficient) by the coefficient element 131 to detect the column rotation angle detection value γ _e and the column. The detected rotational angular velocity is (dγ / dt) _e .

Further, a value obtained by multiplying the detected angle value θ _e by the speed reduction ratio L / 2π is subtracted from the detected position value (x _l ) _e . Further, the column position detection value γ _e has a geometrical constant (constant regarding the geometrical relationship between the bed 4 and the position detector 21) h.
_The value obtained by multiplying _cs is subtracted, and the value obtained by multiplying the bed position detection value φ _e by the geometric constant h _bl is added to obtain the ball screw elastic deformation detection value (x _n ) _e . The position differential detection value with respect to (dx _l / dt) _e, the angular velocity detection value (d [theta] / d
t) A value obtained by multiplying _e by the speed reduction ratio L / 2π is subtracted.

Further, the column rotation angular velocity detection value (dγ /
A value obtained by multiplying dt) _e by a geometric constant (constant regarding the geometrical relationship between the column 2 and the position detector 21) h _cs is subtracted,
The value obtained by multiplying the bed rotation angular velocity detection value (dφ / dt) _e by the geometric constant h _bl is added to obtain the ball screw elastic deformation velocity detection value (dx _n / dt) _e . In this way
After all, eight detection values (angle detection value θ _e , angular velocity detection value (dθ / dt) _e , corresponding to eight state quantities of the mechanical system 76,
Ball screw elastic deformation speed detection value (dx _n / dt) _e , ball screw elastic deformation detection value (x _n ) _e , bed rotation angle detection value (φ) _e , bed rotation angular velocity detection value (dφ / dt)
_e , column rotation angle detection value (γ) _e , column rotation angular velocity detection value (dγ / dt) _e ) are obtained. The vibration suppression control torque command T _v ^* is obtained by multiplying these by the vibration suppression control gains 158 to 165 and adding the results.

[0123] Thus, the ball screw elastic deformation detection value corresponding to the relative displacement obtained by subtracting the detected angle value theta _e from the position detection value _{(x l) e (x n} ) e are fed back to a servo system 75. This feedback acts to dampen the most unstable mechanical resonance near the crossover frequency of the servo system 75. Further, the ball screw elastic deformation detection value (x _n) the angular velocity detection value from _{e (dθ} / dt) ballscrew elastic deformation speed detected value corresponding to the relative velocity obtained by subtracting the _e (dx _n / dt) _e is the servo system 75 To be fed back. This feedback acts to dampen the second mechanical resonance, which is destabilized by the relative displacement feedback.

FIG. 6 shows a processing flowchart in which the processor in the servo amplifier 17 executes the vibration suppression control shown in FIG. The operation of the processor will be described below with reference to this flowchart.

[0125] First, the position detection value (x _{l) e,} the speed detection value (dx _l / dt) _e, the angle detection value theta _e, the angular velocity detection value (dθ / dt) _e, Bed detected acceleration value (α _{b) e} , Column acceleration detection value (α _c ) _e is read (step ST
101), the bed acceleration detection value (α _b ) _e to the integrator 12
The low-pass filter process by 2,124 is performed to calculate the bed velocity v _b and the bed displacement x _b (step ST1).
02).

Next, the column acceleration detection value (α _c ) _e is low-pass filtered by the integrators 126 and 128 to calculate the column velocity v _c and the column displacement x _c (step ST103). Furthermore, the bed displacement _xb is 1 / h
_The bed rotation angle detection value φ _e is calculated by multiplying by _lsa , and the bed rotation angular velocity detection value (dφ / dt) _e is calculated by multiplying the bed speed v _b by 1 / h _lsa (step S
T104).

Next, the column displacement x _c to the bed displacement x
After subtracting _b , 1 / h _btc is multiplied to calculate the column rotation angle detection value γ _e , and the column speed v _{c is converted} to the bed speed v
After subtracting _b , 1 / h _btc is multiplied to calculate a column rotation angular velocity detection value (dγ / dt) _e (step ST1).
05). Further, the calculated position detection value ( _xl ) _e , angle detection value θ _e , bed rotation angle detection value φ _e, and column rotation angle detection value γ _e are considered in consideration of the coefficients L / 2π, h _bl , h _cs. The screw elastic deformation detection value (x _n ) _e is calculated (step ST106).

[0128] The speed detection value (dx _l / dt) _e, the angular velocity detection value (dθ / dt) _e, Bed rotational angular velocity detected value (dφ / dt) _e, the column rotation angular velocity detection value (d [gamma] / d
t) coefficients from _e L / _2π, h _bl, taking into account the h _cs is calculated ballscrew elastic deformation rate change detection value (dx _n / dt) _e (step ST 107).

Next, the position detection value ( _xl ) _e , the angle detection value θ _e , the angular velocity detection value (dθ / dt) _e , the velocity detection value (dx _n / dt) _e , the ball screw elastic deformation detection value (x
_n ) _e , bed rotation angle detection value φ _e , bed rotation angular velocity detection value (dφ / dt) _e , column rotation angle detection value γ _e ,
The column rotation angular velocity detection value (dγ / dt) _e has a coefficient K _m0 ~
After being multiplied by K _m8 , the sum of them is calculated to calculate the vibration suppression control torque command T _v ^* (step ST108). By the above control, the mechanical resonance is suppressed more than in the conventional case, and as a result, the position feedback gain K _p in the position loop of the servo system 75 and the speed feedback gain K _v in the speed loop can be made higher. .

Example 2. Vibration suppression control gain 158-1
The setting method of 65 will be described. The mechanical system 76 shown in FIG. 2 can be represented by a state equation as follows. dx _m / dt = A _m x _m + b _m T _m (1) where x _m = {x _n , dx _n / dt, θ, dθ / dt, φ, d
φ / dt, γ, dγ / dt} ^T , and the system matrix A _m and the input vector b _m are as shown in FIG. 7.

Dead time element 1 of the velocity loop shown in FIG.
The dynamic characteristics of the 34th and 0th-order holders 133 are expressed by the first-order Padé approximation as shown in Expression (2). (Dθ / dt) _a = {1 / (1 + τ _v s / 2)} · dθ / dt (2) where (dθ / dt) _a is the angular velocity detection value in the Padé approximation model.

Further, the dynamic characteristics of the dead time element 80 of the position loop and the 0th-order holder 79 shown in FIG. 1 are expressed by the second-order Padé approximation as shown in equation (3). In _{(x l) a = {1} / (1 + τ p s / 2 + τ p 2 s 2/12)} · dθ / dt ... (3) where the position detection value at (x _{l) a} is Pade approximation model.

Using equations (1), (2), and (3), the dynamic characteristics of the system in which the movable portion of the mechanical system 76 and the servo system 75 are combined can be described by the equation of state (4). Indicated by. dx _p / dt = A _p x _p + B _p u _p (4) where x _p = {x _n , dx _n / dt, θ, dθ / dt, φ, d
φ / dt, γ, dγ / dt, (dθ / dt) _a , (x
_l ) _a , ( _xl ) _b } ^T , and ( _xl ) _b is a variable derived when the quadratic Padé approximation formula (2) is expressed in the state space.

Further, u _p = {x _l ^* , T _m }.

Since the system matrix A _p of the equation (4) is decoupled in the modal coordinate system, the spectrum is decomposed into the equation (5).
As shown in. A _p = E _p Λ _p E _p ^-1 (5) Here, Λ _p is a diagonal matrix of eigenvalues, E _p is a mode matrix, and real and complex numbers are mixed in the elements of each matrix.

When the system matrix A _p is decomposed into the block diagonal matrix A _p in order to obtain the real eigenvectors for implementing the control law, the formula (6) is obtained. A _p = E _b A _b E _b ^-1 (6) Here, E _b = Re {E _p } + I _m {E _p }. The maximum number of block diagonal matrix elements of the block diagonal matrix A _b is 2 × 2, which means that they are decoupled into a primary system and a secondary system. Since the secondary system is equivalent to the one-degree-of-freedom vibration system
This non-coupling facilitates vibration suppression control.

With the left real mode matrix E _b ^-1 , the state vector x _{p in} the physical coordinate system of equation (4) can be converted into the state vector x _m in the mode coordinate system as shown in equation (7), and x _m = E _b ^-1 x _p (7) When the equation (4) is represented by the mode coordinates, the equation (8) is obtained. _{dx m / dt = A b x} m + B b u p ... (8) where a ^{_{B b = E b -1 B p}} .

Furthermore, the noncoupling secondary system is subjected to rotational coordinate conversion for each mode. As the transformation matrix T _r , its dimension is A
_A square block diagonal matrix equal to _b , where the block diagonal element is the rotation transformation matrix of the rotation angle θ _j when the corresponding element of A _b is the block matrix, and 1 when the corresponding element of A _b is the scalar diagonal element. Set what is. Where the subscript j
Is an integer, and θ _j is given by equation (9). θ _j = tan ⁻¹ {(A _{b, jj} B _{b, 2j} + A _{b, j + 1} , _j B _{j, 2, j + 1} ) / (A _{b, j + 1} , _j B _{b, 2j} −A _{b , jj} B _{b, 2, j + 1} )} (9) Here, the subscript j of A _b and B _b indicates the element of each matrix.

This transformation matrix T _r and E _b allows x _m to be
If it is converted to _v by the equation (10), x _v = (E _b T _r ) ⁻¹ x _m (10) The j-th element of x _{v has} a phase of 90 degrees at the mechanical resonance frequency with respect to the motor torque T _m . A signal corresponding to the delayed speed is obtained, and the vibration suppression control can be performed by multiplying this signal and adding the motor torque command value. For example, when simultaneously suppressing and controlling n mechanical resonances, the vibration suppression control torque command T _v ^* is given by Expression (11). T _v ^* = Σ _{m = 1} ⁿ K _sm x _{v, jm} (11) where K _sm (m = 1 to n) is a vibration suppression control gain set according to the degree of vibration suppression for each mechanical resonance. And
The subscript jm of x _v is the element number of the velocity equivalent signal corresponding to the suppressed mechanical resonance.

After all, from the expressions (10) and (11), the relationship between the state quantity x _m of the physical coordinate system and the vibration suppression control torque command T _v ^* is determined as shown in the expression (12). T _v ^* = k _t0 (x _l ) _a + K _t1 θ + K _t2 dθ / dt + K _t3 x _n + K _t4 dx _n / dt + K _t5 φ + K _t6 dφ / dt + K _t7 γ + K _t8 dγ / dt + K _t9 dθ / dt (12), (12) Expression (12) shows the case where the mechanical resonance is 3.
In the actual operation of the control system, the state quantity of the physical coordinate system of Expression (12) is the detection value (position detection value ( _xl ) _e ,
Angle detection value θ _e , angular velocity detection value (dθ / dt) _e , ball screw elastic deformation detection value (x _n ) _e , ball screw elastic deformation velocity detection value (dx _n / dt) _e , bed rotation angle detection value (φ ) _E , bed rotation angular velocity detection value (dφ / dt) _e ,
The column rotation angle detection value (γ) _e and the column rotation angular velocity detection value (dγ / dt) _e ) are replaced, and the vibration suppression control gains 158 to 166 shown in FIG. 4 are replaced by K _{t0 to} K _{t8 in the} equation (12).
Give by. However, the vibration suppression control gain 159 is given by the sum of K _t2 and K _t9 .

FIG. 8 shows a result obtained by simulating the operation state of the vibration suppression control based on the block diagonalization mode separation described above. FIG. 8 shows frequency transfer characteristics from the position command value x _l ^* to the position detection value (x _l ) _e .
The broken line in the figure is when the vibration suppression control is not performed, and the gain is large near the dimensionless frequency 2 due to the mechanical resonance R1. The solid line shows the result of the vibration suppression control so as to suppress only the mechanical resonance R1. It can be seen that the gain of the mechanical resonance R1 is reduced, and the phase change is moderated and stabilized. On the other hand, mechanical resonance R0,
R2 has hardly changed. Although the mechanical resonances R0 and R2 are very close to the mechanical resonance R1, only the mechanical resonance R1 is selectively stabilized, and the effectiveness of the vibration suppression control in this embodiment can be confirmed.

Example 3. FIG. 9 is a flowchart showing the operation of the processor of the numerical controller in the positioning system according to the third embodiment of the present invention. The operation of the numerical controller 8 for setting the control gain of the above mode control will be described below.

First, the constants 1 / J, J _t / Jms, and the coefficient factors 86, 90, and 99 relating to the mass of the mechanical system 76,
I _d , coefficient element 93, 97, 102, 11 relating to rigidity
2, 104, 106, 110 constant K _n , a ₁ ,
a ₃ , a ₅ , a ₇ , a ₉ , a ₁₁ and coefficient elements 94, 98, 103, 113, 105, 107, 111 related to damping
Constants c _n , a ₁ , a ₄ , a ₆ , a ₈ , a ₁₀ , a
₁₂ , coefficient elements 95, 96, 89 related to geometric shapes
The constants h _b , h _n , L / 2π, h at 114 and 115
_b1 , h _cs, etc. are input from the operation panel 345 (FIG. 32) (step ST201). Then, the processor of the numerical controller 8 calculates A _b , B _b , E _b-1 , and θ _J based on the equations (5), (7), and (8) (step ST2).
02).

Next, the machine resonance frequency and the vibration mode are displayed on the display 300 of the operation panel 345, and the vibration mode (machine resonance) is numbered, for example, in the order from the lowest machine resonance frequency. When the user inputs the machine resonance number m to be suppressed from the operation panel 345 (step ST2
03), the mechanical resonance that is the target of the vibration suppression control is set. Regarding the speed equivalent state quantity x _{vj in} the mode coordinates of the set vibration mode, the frequency transfer characteristic (frequency response) from the motor torque T _m is displayed on the Bode diagram 300.
Is displayed (step ST204).

In the Bode diagram, a straight line where the loop gain (gain of the vibration suppression control effect) is 0 dB is displayed. The user inputs a loop gain determined from the desired degree of suppression and the frequency transfer characteristic from the operation panel 345 (step ST205). Then, the processor of the numerical controller 8 determines the vibration suppression control gain K _sm from the designated loop gain (step ST206).

Further, it is displayed on the display 300 whether or not the vibration suppression control is performed for other mechanical resonances (step ST.
207). The user responds to Y from the operation panel 345 accordingly.
Enter es / No. When "Yes" is input, the process returns to step ST203. If “No”, the vibration suppression control gain K _sm is transferred to the servo amplifier 17 (step ST208). As described above, the vibration suppression controller 7
The vibration suppression control gain K _sm in 8 can be set from the operation panel 345.

The processor of the numerical control device 8 includes
For example, 68030 manufactured by Motorola, Inc. can be used. The power of this processor is sufficient to perform the calculations of this embodiment, and it is not necessary to employ a high-performance processor to implement the positioning device according to this embodiment. Further, here, the one applied to the numerical controller 8 for executing the control shown in the first embodiment or the second embodiment has been described, but the relative displacement / relative velocity feedback in the sixth embodiment described later is described. It is also applicable to the vibration suppression controller based on.

Example 4. FIG. 10 is a flow chart showing the operation of the positioning device which executes the automatic setting operation of the vibration suppression control gain K _sm and the automatic diagnosis operation of the mechanical system by the positioning device according to the fourth embodiment of the present invention. In the above-described third embodiment, the case where the user interactively inputs the vibration suppression control gain K _sm has been described, but the positioning device of this embodiment measures the vibration characteristics of the mechanical system 76 to determine the mechanical system. Diagnosis of the abnormality of 76 and vibration suppression controller 7
The vibration suppression control gain K _sm in 8 is automatically set.

The apparatus configuration according to this embodiment is similar to that shown in FIGS. 32, 33 and 35, and includes the control system shown in FIG. In this case, the numerical control device 8 has a gain setting unit that performs the following processing.

First, the user inputs constants such as selection of the drive axes X, Y, Z and designation of the vibration frequency range from the operation panel 345 of the numerical controller 8 (step ST301). The gain setting unit of the numerical controller 8 outputs a vibration signal to the servo amplifier 17 according to a user's input to vibrate the mechanical system 76. Then, the position detector 21 and the rotation angle detector 7
The detection signal and the motor drive current are fetched via the servo amplifier 17 (step ST302).

Here, the vibration signal supplied from the numerical controller 8 to the servo amplifier 17 has a frequency of 10 Hz, for example.
The sine wave increasing at 1 / min may be given from 1 Hz to 1 kHz, or white noise having a frequency band of 1 Hz to 1 kHz may be used. Further, this vibration signal can be given as the position command value x _l ^* , and may be given so as to be added to the speed command (dθ / dt) ^* and the motor torque command T _m ^* . Further, it is possible to examine the interaction between the mechanical system 76 and the servo system 75 by opening and closing the position loop and the velocity loop during the vibration. The detection signal and the motor drive current are recorded in the numerical controller 8 for a certain period of time.

Next, the gain setting section of the numerical controller 8 obtains the frequency transfer characteristic from the vibration signal and the recorded data, and from the frequency transfer characteristic, the natural frequency of the mechanical system 76,
The damping ratio, eigenmode, etc. are identified (step ST30).
3). When the identified natural frequency is below the design allowable value, it is determined that there is an abnormality in the part of the mechanical system related to the natural frequency (step ST304). The contents are collated with a database stored in the numerical control device 8 and displayed on the display 300 together with possible causes. After displaying such a diagnosis result, the user is prompted to input to continue or cancel the process by displaying the display 300 (step ST305). The user inputs continuation or cancellation from the operation panel 345.

When the stop is input, the process is terminated as it is, and when the continuation is input, the model is identified from the transfer characteristic, the natural frequency, and the natural mode obtained in step ST303. For example, the third embodiment. The control system is set by the method shown in (step ST306). In addition, when it is excited by white noise, the natural frequency, the natural mode, and the model can be identified by the data processing in the time domain such as the AR model.

Example 5. FIG. 11 is a mechanical system 76 of the vibration detector in the positioning device according to the fifth embodiment of the present invention.
It shows the state of attachment to. Column 2 and bed 4
Is shown in a left-right symmetrical section (in the YZ plane) in the X direction, but since the column 2 and the bed 4 are cast box-shaped structures, they have a hollow structure as shown in the figure. In the figure, 1
74 is a vibration detector attached to the column 2 from the inside,
Reference numeral 167 is a signal cable of the vibration detector 174, 168 is a vibration detector mounted inside the bed 4, and 169 is a signal cable of the vibration detector 168.

Next, the operation will be described. Although ribs 170 are arranged inside the bed 4, holes are formed in these ribs 170. The signal cable 169 passes through each hole, exits the bed 4 from the hole 171 on the rear surface of the bed, and is connected to the servo amplifier 17. Similarly, although ribs 172 are arranged inside the column 2, these ribs 1
A hole is provided at 72. And the signal cable 16
7 passes through each hole, exits the column 2 from the hole 173 on the rear surface of the column 2, and is connected to the servo amplifier 17.

Then, the processor of the servo amplifier 17 executes the operation described in the first embodiment and performs the positioning process. In this case, in particular, since the vibration detector and its signal cable are arranged inside the structure, it is possible to reduce external contact and impact, and thus the signal cable 1
It is possible to prevent disconnection of 67 and 169 and failure of the vibration detectors 174 and 168 due to excess of allowable acceleration.
Further, since the vibration detectors 174 and 168 are arranged in the non-movable part, compared with the device in which the vibration detector is arranged in the movable part as shown in FIG. It is characterized by improved noise resistance and reliability.

Example 6. FIG. 12 is a block diagram showing a vibration suppression controller in a positioning device according to a sixth embodiment of the present invention. 1st Example, 2nd Example, 3rd
In this embodiment, the vibration detector is used to perform the vibration suppression control, but the position detector 21 is not used.
It is also possible to perform vibration suppression control using only the rotation angle detector 7 attached to the motor shaft of the servo motor 6. The positioning apparatus according to this embodiment uses such a vibration suppression controller, omits the vibration detector system 77 shown in FIG. 1, and changes the internal configuration of the vibration suppression controller 78. .

In FIG. 12, x _r is the position detection value (x
_l ) relative displacement obtained by subtracting the detected angle value θ _e from _e , v _r
Is a relative speed obtained by subtracting the rotational angle detection value (dθ / dt) _e of the motor shaft from the time change rate dx _l / dt of the position detection value of the machine movable part, and 181 is the relative displacement feedback gain K _rd in the relative displacement x _r. relative displacement feedback gain multiplier multiplying, 180 relative velocity v relative velocity feedback gain multiplier multiplying the relative velocity feedback gain K _rv to _r, T _VRV intended to relative velocity feedback gain K _rv is subjected to the relative velocity v _r A certain relative speed control torque, T _vrd is a relative displacement control torque that is the relative displacement x _r multiplied by the relative displacement feedback gain K _rd , and T _vr ^* is the vibration suppression control that is the output of the vibration suppression controller in this case. It is a torque command.

Next, the operation will be described. FIG. 13 is a processing flowchart of the vibration suppression control executed by the processor of the servo amplifier 17. The signal processed by the processor is a value in which the physical quantity is quantized through the position, the resolution of the angle detector and the A / D converter, so here, the curly brackets “{}” are added to distinguish it from the physical quantity. It is shown separately. Also,
Since the processing routine that implements the vibration suppression control is repeatedly executed at fixed time intervals in synchronization with the speed loop processing,
The execution time is indicated by a subscript in curly braces, assuming that the process at the current time is the nth time.

From the position detector 21 and the rotation angle detector 7 attached to the mechanical system 76 to the vibration suppression controller, that is, the processor of the servo amplifier 17, the rotation angle θ and each speed detection value (dθ / dt). , Position detection value ( _xl )
_e and the time change rate dx _l / dt of the position detection value are supplied. First, the processor of the servo amplifier 17 reads the position detection value {(x _l ) _e } _n (step ST40
1), the detected angle value {θ _e } _n is read (step ST
402). Next, the position detection value {(x
_l ) _e } The position detection value previously read from _n {(x _l )
_e } _n-1 is subtracted and the rate of change over time {(dx _l / dt)
calculates _{e} n} (step ST 403), read the detected angle value currently {theta _e} angle detection value previously read from _n {θ _e} angular velocity detection value by subtracting _{n-1 {(dθ} / d
t) _e } _n is calculated (step ST404).

Further, the relative displacement {x _r } _n is calculated by subtracting the angle detection value {θ _e } _n obtained by multiplying the position detection value {(x _l ) _e } _{n by} the quantized conversion value L'of the ball screw lead. (step ST 405), the relative speed by subtracting the time rate of change of the position detection value _{{(dx l / dt) e} } angular velocity detection value obtained by multiplying the quantized converted value L 'from _{n {(dθ / dt) e} } n calculating a {v _{r} n} (step ST 406).

Then, the relative displacement {x _r } _n is multiplied by the quantized relative displacement feedback gain K _rd 'to calculate the relative displacement control torque {T _vrd } _n (step ST4).
07), calculates the relative velocity {v _r} relative speed control torque {T _VRV} is multiplied by the relative displacement feedback gain K _rv 'converted quantized _{n n} (step ST 408).

Further, the relative displacement control torque {T _vrd } _n and the relative speed control torque {T _vrv } _n are added to calculate the vibration suppression control torque command {T _vr ^* } _n (step ST
409). The processor of the servo amplifier 17, that is, the vibration suppression controller outputs the vibration suppression control torque command {T _vr ^* } _n to the servo system 75. In the servo system 75, the vibration suppression control torque command {T _vr ^* } _n and the servo torque command T _ms ^*
And are added to calculate the motor torque command T _m ^* . Then, the torque generation means 196 performs current control for causing the servo motor 6 to generate a corresponding torque. By the above control, the vibration of the mechanical system 76 is suppressed.

FIG. 14 shows the result of an experiment of vibration suppression control based on this embodiment. FIG. 14 shows the position command value x
_It represents the frequency transfer characteristics from _l ^* to the position detection value ( _xl ) _e . A broken line shows a transfer characteristic without vibration suppression control, and a solid line shows a transfer characteristic with vibration suppression control. As shown in FIG. 14, the vibration suppression control reduces the gain of the mechanical resonance R1 by about 10 dB and reduces the gain of the mechanical resonance R2 by about 5 dB. That is, the effectiveness of the vibration suppression control in this example can be confirmed.

Example 7. FIG. 15 is a flow chart showing another example of the vibration suppression control executed by the processor of the servo amplifier 17 in the positioning device according to the seventh embodiment of the present invention. That is, FIG. 15 is a flowchart showing the operation of the vibration suppression controller different from that of the sixth embodiment.

First, the processor of the servo amplifier 17
Position detection value _{{(x l) e} n} , reads the detected angle value {θ _{e} n} (step ST 501, ST 502). Next, in this case, the detected angle value {θ _e } _n obtained by multiplying the detected position value {(x _l ) _e } _{n by} the quantized conversion value L of the ball screw lead is read. Furthermore, the position detection value {(x _l )
Relative displacement {x _r } by subtracting the angle detection value {θ _e } _n obtained by multiplying the quantized conversion value L'of the ball screw lead from _e } _n
n is calculated (step ST503). The relative velocity {v _r } _n is obtained by subtracting the previously calculated relative displacement {x _r } _{n- 1} from the current time relative displacement {x _r } _n thus calculated.
Is calculated (step S504).

Hereinafter, step ST505 to step ST
508, steps ST407 to ST4 in FIG.
Similarly to 10, the vibration suppression control torque command {T _vr ^* }
_{n is} calculated and output to the servo system 75.

Comparing this embodiment with the sixth embodiment,
Although the memory for storing the relative displacement {x _r } _n-1 is increased, there is an advantage that the processing procedure is reduced by 2 steps.

Example 8. FIG. 16 is a block diagram showing a vibration suppression controller 78 in a positioning device according to an eighth embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 12 represent the same or similar components. 187 is a high pass filter (filter means), and T _vrh ^* is a vibration suppression control torque that filters a low frequency band. The vibration suppression controller 78 according to this embodiment is
This corresponds to the one in the seventh embodiment to which a high-pass filter 187 is further added.

As shown in FIG. 16, the high pass filter 1
87 has a transfer characteristic represented by the following equation using the Laplace operator s. G _h (s) = τ _h s / (τ _h s + 1) (13) On the other hand, assuming that the sampling period is T, the bilinear transformation becomes the following equation: s = 2 (1-z ⁻¹ ) / T ( 1 + z ⁻¹ ) (14) When the equation (14) is substituted into the equation (13), the transfer characteristic G _h (z) of the high-pass filter in the discrete system is given by the following equation. _{G h (z) = 2τ h} (1-z -1) / (2τ h + T) {1- (2τ h -T) z -1 / (2τ h + T)} ... (15)

FIG. 1 is a block diagram showing the above equation (15).
It becomes like 7. In FIG. 17, reference numeral 601 denotes a vibration suppression control torque command {T _vr ^* } _n with a gain of {2τ _h · 2 ^b1 /
A gain multiplier that multiplies (2τ _h + T)}, {X_1} _n
Is the output of this gain multiplier 601, and 602 is {XS_
0} _n is a converter that makes the value {XS_0} _n-1 in the previous processing routine, 604 is a gain multiplier that multiplies {XS_0} _n-1 by 2 ^-b2 , and 605 is the output of the gain multiplier 604 {X
_TM} _n has gain {(2τ _h −T) · 2 ^b2 / (2τ _h
+ T)} for multiplying the gain multiplier 603 by the above {XS_
This is a gain multiplier that outputs {T _vrh ^* } _n by multiplying 0} _n-1 by subtracting {XF_1} _n by 2 ^-b1 . Also,
{XS_0} _n and {XF_1} _n are gain multipliers 60
1 is the sum of the output of {X_1} _n and the output of the gain multiplier 605.

Next, the operation will be described. FIG. 18 is a flowchart showing the processing of the high-pass filter 187 executed by the processor of the servo amplifier 17, which executes the operation of the block diagram shown in FIG. First, the vibration suppression control torque {T _vr ^* } _n generated as a result of the processing of FIGS. 12 to 15 is read (step ST7).
01). Then, this vibration suppression control torque command {T
_vr ^* } _n is multiplied by the gain {2τ _h · 2 ^b1 / (2τ _h + T)} to calculate {X_1} _n (step ST70).
2). Next, {XS_0} _n-1 is multiplied by 2 ^-b2 and {X_T
M} _n is calculated (step ST703). further,
To {X_TM} _n gain _{{(2τ h -T) · 2} b2 / (2
τ _h + T)} and {X_1} _n are added to this to calculate {XF_1} _n (step ST704). Then, pull the {XF_1} _n from {XS_0} _n-1, 2
^Multiply by ^-b1 to calculate {T _vrh ^* } _n (step ST70)
5). {XF_1} _n is stored in {XS_0} _n (step ST706), and {T _vrh ^* } _n is output to the current loop (step ST707).

The high-pass filter 187 configured as described above and the transfer characteristics from T _vr ^* to T _vrh ^* obtained by experiment are shown in FIG. The horizontal axis is the dimensionless frequency normalized by 1 / τ _h . Although implemented in a discrete system by a digital processor, the original continuous system transfer characteristic shown in Expression (13) is obtained. That is, the gain is -3 dB at the corner frequency 1 / τ _h , and the phase is advanced by 45 degrees. At a frequency lower than the break frequency, the gain is reduced with a slope of 20 dB / dec, and the low frequency signal is removed. For example, when the dimensionless frequency is 0.1, the gain is -20 dB.
At a frequency higher than the break point frequency, the gain is almost 0 dB, and the input signal is transmitted as it is.

Next, the operation and effect of this embodiment will be described. In the vibration suppression control of the sixth and seventh embodiments described above, that is, when the high-pass filter, which is a requirement of this embodiment, is not used, the detected position value ( _xl ) _{e is changed} to the torque command value T _m ^* . The gain is given by the following equation. G _ld = (T _m ^* ) / (X _l ) _e =-(L / 2π) K _p K _v + K _rd (16) On the other hand, from the angle detection value (θ) _e to the torque command value (T _m ^* ) The gain of is given by the following equation. G _ed = (T _m ^* ) / (θ) _e = −K _rd (17) The ratio between the gain from the position detection value to the torque command value and the gain from the angle detection value to the torque command value is expressed by equation (16). ), From equation (17): G _ed / G _ld = −K _rd / {K _rd − (L / 2π) K _p K _v } (18)

Expression (17) is two signals related to the position of the saddle table 3 shown in FIG. 32, the position detection value (X _l ).
_The contribution of _e and the detected angle value (θ) _{e to} the torque command value is shown. Then, when the relative position feedback gain K _rd becomes a value close to (L / 2π) K _p K _v , G _ed /
G _ld becomes a large value, and the contribution of the position detection value approaches zero. However, the position detection value (X _l ) _e is the angle detection value (θ)
This tendency is undesirable because it is often closer to the actual position of the saddle table 3 than to _e . In particular, since the static positioning accuracy depends on the low frequency band, if the contribution of the position detection value (X _l ) _{e to} the torque command value in the low frequency band is saved, the position accuracy is improved. Therefore, in this embodiment, the influence of the equation (18) is removed by providing the high pass filter 187.

The simulation results in this example are shown in FIG. It is a closed loop transfer characteristic from the position command value to the position detection value. The solid line shows the result of this embodiment, the broken line shows the result of the sixth embodiment, and the alternate long and short dash line shows the result of the conventional example without vibration suppression control. Compared with the conventional example, the mechanical resonance R1 is different in this example and the sixth example.
Is significantly stabilized, and the vibration amplitude of resonance is 10 dB.
It can be reduced more than that. Further, it can be seen that the vibration suppressing effect of this embodiment is slightly lower than that of the sixth embodiment, but the vibration can be significantly suppressed as compared with the conventional example. In this simulation, the break point frequency 1 / τ _h of the high pass filter 187 is set to 1/10 of the frequency of the mechanical resonance R1.

A true circle accuracy measurement test of the processing machine positioning table according to this example was carried out. FIG. 21 shows the result compared with the conventional example. FIG. 21 (a) shows the test result of this example, and FIG. 21 (b) shows the test result of the conventional example. The results shown in FIGS. 21 (a) and 21 (b) are obtained by moving the table in the horizontal plane and drawing a circular locus. In the test, the table is positioned by two axes, the x-axis and the y-axis. In the conventional example, positioning is performed by feedback of the detected angle value. According to the positioning device of this example, a smooth circular locus was obtained as shown in FIG. On the other hand, as shown in FIG. 21B, it can be seen that in the conventional example, a protrusion is generated at the time of quadrant switching in which the signs of the speeds of the respective axes are switched. From this experimental result, it can be seen that in this embodiment, the feedback effect of the position detection value is maintained by the high-pass filter, and highly accurate positioning is possible.

This example was applied to a die-sinking electric discharge machine and a machining test was conducted. FIG. 22 shows the time waveform of the voltage between contacts in the processing test. The upper diagram in FIG. 22 is based on this embodiment, and the lower diagram is based on a conventional example without vibration suppression control. In the conventional example, the inter-electrode voltage hunts from around 2 of the dimensionless time, but this is due to the vibration of the mechanical system. On the other hand, when the positioning device according to this embodiment is used, such hunting does not occur, and it is understood that stable discharge is maintained. Thereby, the processing speed is improved, and as a result of the test, the processing speed when the positioning device according to this embodiment is used is
It has been revealed that the processing speed reaches twice or more the conventional processing speed. According to the test, the speed of the horizontal single-axis finishing of the die-sinking electric discharge machine was increased up to 2.7 times, and the weight ratio of electrode consumption was improved to 1/9.

Example 9. FIG. 23 is a diagram showing the configuration of the torque generating means 196 when the servomotor 6 in the positioning apparatus according to the ninth embodiment of the present invention is a three-phase motor, in which 200 is a current controller and 204 is a current amplifier. , 205 and 206 are u-phase and v-phase current detectors, respectively.

In the sixth to eighth embodiments described above,
Although the rotation angle detector 7 attached to the motor shaft of the servo motor 6 is used to detect the relative displacement and the relative speed, the rotation angle detector 7 can be used for current control of the servo motor 6.

FIG. 24 is a block diagram showing the configuration of the current controller 200 shown in FIG. 23. In FIG. 24, 210 is the phase current detection values (I _u ) _e , (I _v ) _e ,
A rotation dq that receives (I _w ) _e and the detected angle value θ _e, and outputs motor torque T _m , d-phase current I _d , and electrical angle θ _d.
A conversion means, 211 is a PID compensator for the d-phase current, 212 is a PID compensator for the torque deviation T _me , and 213 is a d-phase current command I _d ^* , a q-phase current command I _d ^* , and an electrical angle θ _d as inputs. ,
It is a two-phase / three-phase conversion unit that outputs the three-phase current commands I _u ^* , I _v ^* , and I _w ^* .

Next, the operation will be described. As shown in FIG. 23, the motor torque command T _m ^* and the detected angle values θ _e , u
Phase current detection value (Iu) _e , and v phase current detection value (Iu)
The operation of the current controller 200 which receives v) _e as an input and outputs the three-phase current commands I _u ^* , I _v ^* , and I _w ^* is executed by the processor of the servo amplifier 17, for example. The block diagram of the current controller 200 is shown in FIG. 24, and the processing contents performed by the processor are shown in a flowchart of FIG.

As shown in FIG. 25, the current controller 200
First, the angle detection value θ _e and the u-phase current detection value (I _u )
The current detection values (I _v ) _e of the _e and v phases are read (steps ST601, ST602, ST603). Next, u-phase and v-phase current detection values (I _u ) _e and (I _v ) _e
Is added after inverting the sign to calculate the w-phase current detection value (I _w ) _e (step ST604). Also, the detected angle θ _e is multiplied by the number p of pole pairs of the servo motor 6 to calculate the electrical angle θ _d (step ST605).

Then, from the u-phase, v-phase, and w-phase current detection values (I _u ) _e , (I _v ) _e , and (I _w ) _e , equation (19),
The q-phase current I _q and the d-phase current I _d are calculated according to the equation (20) (steps ST606 and ST607). _{I q = (2/3) {(} I u) e cosθ d + (I v) e (cosθ d - (2/3) π) + (I w) e (cosθ d + (2/3) π) _{} ... (19) I q =} (2/3) {(I u) e sinθ d + (I v) e (sinθ d - (2/3) π) + (I w) e (sinθ d + (2 / 3) π)} (20)

Furthermore, the motor torque detection value T _md is calculated by multiplying the q-phase current I _q by the torque constant K _i (step S).
T608). The motor torque command T _m ^* is read (step ST609), and the motor torque detection value T _md is subtracted from the motor torque command T _m ^* to calculate the torque deviation T _me (step ST610).

The current controller 200 further PID-compensates the torque deviation T _me to set the q-phase current command I _q ^* (step ST611), and PID-compensates the d-phase current I _d to d-phase current command I. _d ^* is set (step ST612). Then, three-phase current commands I _u ^* , I _v ^* , and I _w ^* are calculated from Iq ^* , Id ^* , and θd according to the equations (21), (22), and (23) (steps ST613, ST614, ST615). ),
These three-phase current commands I _u ^* , I _v ^* , I _w ^* are applied to the current amplifier 2
04 (step ST616). I _u ^* = I _q ^* cos θ _d + I _d ^* sin θ _d (21) I _v ^* = I _q ^* cos (θ _d − (2/3) π) + I _d ^* sin (θ _d + (2/3)) π) (22) I _w ^* = I _q ^* cos (θ _d + (2/3) π) + I _d ^* sin (θ _d + (2/3) π) (23)

The current amplifier 204 shown in FIG.
It is composed of an M circuit, a base drive circuit, and a main circuit, and in accordance with the three-phase current commands I _u ^* , I _v ^* , I _w ^* , the three-phase currents I _u , I
Generate _v and I _w . The servo motor 6 generates a motor torque T _m by the three-phase currents I _u , I _v , and I _w , and drives the mechanical system 76. Further, the u-phase current I _u and the v-phase current I _v are detected by the current detectors 205 and 206 and converted into current detection values (I _u ) _e and (I _v ) _e, and the current controller 20.
It is taken into 0.

When the AC servomotor is used, the relationship between the winding current and the motor-generated torque is calculated based on the rotation angle of the motor shaft. Therefore, the rotation angle of the motor shaft must be detected. As in this embodiment, the rotation angle detector 7 of the motor shaft for detecting the relative displacement is also used as the angle detector for driving the motor, so that the angle detector for driving the motor can be reduced. On the contrary, when an angle detector for driving the motor is installed, the angle detector may be used to calculate the relative displacement for vibration suppression. In that case, the rotation angle detector 7 for vibration suppression control can be omitted.

Further, the reduction of the angle detector can be applied not only to the vibration suppression control utilizing the relative displacement and the relative speed according to the fourth and fifth embodiments, but also to the first and second embodiments. It can also be applied to the vibration suppression control by the mode control shown in the embodiment.

Example 10. In the sixth embodiment and the seventh embodiment, the relative displacement x _r and the relative speed v _r may be fed back to the servo motor that drives the head 1 in the Z-axis direction. By driving the head 1 in the Z-axis direction, the bed 4 receives a bending moment due to the inertial force of the head 1 and elastically deforms, and a mechanical resonance R1 occurs. This elastic deformation is also detected as the relative displacement x _r of the Y axis and the relative velocity v _r . Therefore, the relative displacement x _r of the Y axis and the relative velocity v _r
By feeding back to the servomotor for driving the head 1, the mechanical resonance R1 can be reduced in the same manner as in the sixth and seventh embodiments.

As shown in FIGS. 32 and 33, the head 1 is driven by a Z-axis servo motor 306 that drives the head 1 in the vertical direction.
Although not explicitly shown in FIGS. 32 and 33, is driven by the torque generating means similar to that shown in FIG. Also,
A servo amplifier is provided to control the servo motor. The servo amplifier realizes a servo system and a vibration suppression controller similar to those shown in FIG.

The relative displacement and relative velocity of the Z-axis are detected from the position detector 321 mounted between the head 1 and the column 2 and the angle detector 307 attached to the Z-axis servomotor 306 for driving the head 1. By feeding these back to the servo motor 306, it is possible to suppress mechanical resonance caused by elastic deformation of the Z-axis ball screw 314 corresponding to mechanical resonance R2 in the sixth and seventh embodiments. . Further, it may be carried out together with the feedback of the relative displacement of the Y axis and the relative speed.

Example 11. FIG. 26 is a block diagram showing the structure of the observer in the positioning device according to the eleventh embodiment of the present invention. In the first and second embodiments, the vibration suppression controller 78 determines the bed rotation angle based on the bed angular acceleration d ² φ / dt ² and the column angular acceleration d ² / dt ² by the vibration detector. Detection value φ _e , detection value of bed rotation angular velocity (dφ / dt) _e , detection value of column rotation angle γ _e , and detection value of column rotation angular velocity (dγ / d
t) _e was calculated, but in this embodiment, the state quantity related to the vibration of these non-movable parts is estimated using an observer.

In FIG. 26, z is a detection signal, which is expressed by equation (24). z = The _{{(x l) e, (} dx l / dt) e, θ e, (dθ / dt) e} T ... (24), C m is the output is expressed by the following equation.

[0195]

[Equation 1]

L is a matrix of 8 rows and 4 columns, which is an observer gain, and is selected so that the poles of the observer shown in FIG. 26 are stable. Here, x _g is an estimated value of the state quantity x _m and is represented by equation (26). x _g = {(x _n ) _g , (dx _n / dt) _g , θ _g , (dθ / dt) _g , φ _g , (dφ / dt) _g , γ, (dγ / dt) _g } ^T ... ( 26) φ _g of x _{g in} equation (26), (dφ / dt) _g , γ, (d
γ / dt) _g is φ in the vibration suppression controller shown in FIG.
_By giving _e , (dφ / dt) _e , γ, and (dγ / dt) _e , a positioning device without a vibration detector can be configured.

Example 12. FIG. 27 shows the vibration suppression controller 7
28 is a front view showing the appearance of a servo amplifier 17 including a digital circuit in which No. 8 is mounted, and FIG. 28 is a side view thereof.
27 and 28, 420 and 422 are main cards, 424 is a vibration suppression add-on card, and 426 is an arithmetic processor on this vibration suppression add-on card 424. Vibration suppression add-on card 424 is the main card 42
It is attachable / detachable with respect to No. 2 and performs calculation related to the vibration suppression controller 78. The main cards 420 and 422 realize the operation of only the servo system 75 that does not perform the vibration suppression control when the vibration suppression add-on card 424 is not mounted.

If the vibration suppression add-on card 424 is installed, this vibration suppression add-on card 4
In cooperation with 24, the operation of the servo system 75 and the operation of the vibration suppression controller 78 executed on the vibration suppression add-on card 424 are executed. The operation of the vibration suppression controller 78 is as described in the first embodiment, the second embodiment, the sixth embodiment, the seventh embodiment, and the like.

Example 13. 29 is a front view showing a structure around a leveling bolt in a positioning device according to a thirteenth embodiment of the present invention, and FIG. 30 is a sectional view taken along line AA. In FIGS. 29 and 30, 512 is a nut fitted with the leveling bolt 5, and 514 is a spacer interposed between the bed 4 and the nut 512. FIG. 31 is a front view and a top view showing the shape of the spacer 514. Other parts are equivalent to those shown in FIG. 34 of the conventional example.

Next, the operation will be described. The leveling bolt 5 is inserted into the bed 4 from below. Then, the hexagonal portion provided on the lower side is turned by a spanner (not shown) or the like to make the bed 4 horizontal. The leveling bolt 5 is located at a position higher than the lower surface of the bed 4
And the elasticity in the horizontal direction increases. Leveling bolt 5
A spacer 514 is inserted between the bed 4 and the bed 4, and the spacer 514 is tightened with the nut 512. Although the protrusion amount of the leveling bolt 5 from the bed 4 changes depending on the unevenness of the floor 67, the rigidity of the five leveling bolts can be made uniform by adjusting the number of the spacers.
The leveling bolt 5 and the nut 512 are inserted in advance when the positioning device is shipped, and the spacer 514 is
The leveling bolt 5 is laterally inserted from the notch shown in FIG.

If the leveling bolt 5 is lengthened as described above, the elasticity in the lateral direction is increased, and vibrations causing the entire positioning device to swing and translate increase. Since the reaction of the motor drive is absorbed by this vibration, elastic deformation of the mechanical system 76 can be reduced, and mechanical resonance that makes the positioning operation unstable can be reduced.

[0202]

As described above, according to the invention of claim 1, the positioning device includes a vibration detector for detecting the acceleration of the non-movable portion based on vibration, and a vibration suppression control torque to be added to the motor torque command. The command is configured to include a vibration suppression controller that generates by using the outputs of the position detector and vibration detector based on the mechanical analysis model of the mechanical system, so multiple mechanical resonances can be adjusted independently and stably. Therefore, there is an effect that a feedback gain can be significantly increased. Also, relative displacement obtained by subtracting the angle detection value of the rotation angle detector provided on the motor shaft from the position detection value,
Also, it is effective for multiple machine resonances by configuring so that the relative speed obtained by subtracting the angular velocity signal calculated by the calculation processing from the angle detection value from the speed signal calculated by the position detection value is fed back to the servo motor at the same time. Attenuation can be added to the servo, and the servo gain can be increased to achieve high-speed and high-accuracy positioning.

According to the second aspect of the present invention, the positioning device includes one rotary spring for elastic bending deformation of the bed and one positioning spring.
The bed and the column are connected to each other by the rotating dashpot, and one translation spring for elastic deformation of the ball screw connected to the motor shaft of the servomotor and one driving dashpot of the ball screw are connected to the translation dashpot. By one rotary spring and one rotary dashpot relating to elastic deformation of the leveling part that connects to the driven side and adjusts the height of the bed from the floor, or one rotary spring,
Output of the rotation angle detector, output of the rotation angle detector and position detection using a motion analysis model by a system in which the bed and the floor are connected by one translation spring, one rotation dashpot, and one translation dashpot A vibration suppression control torque command is generated using the detected position and its time change rate calculated based on the motion analysis model from the output of the vibration detector, and the rotation angle and angular acceleration of the non-movable part calculated from the output of the vibration detector. Since it is configured as described above, there is an effect that a plurality of mechanical resonances can be independently and stably adjusted and a feedback gain can be significantly increased.

According to the third aspect of the invention, the positioning device includes one rotary spring for elastic bending deformation of the bed and one
The bed and the column are connected to each other by the rotating dashpot, and one translation spring for elastic deformation of the ball screw connected to the motor shaft of the servomotor and one driving dashpot of the ball screw are connected to the translation dashpot. By one rotary spring and one rotary dashpot relating to elastic deformation of the leveling part that connects to the driven side and adjusts the height of the bed from the floor, or one rotary spring,
Using a motion analysis model based on a system in which a bed and a floor are connected by one translation spring, one rotating dashpot, and one translation dashpot, the mode matrix expresses the state quantity in the state equation based on the motion analysis model. Since it is configured to generate the vibration suppression control torque command using the signal converted to the mode coordinates, it is possible to independently stabilize and adjust multiple machine resonances, and greatly increase the servo gain to increase the positioning device's high speed and high altitude. There is an effect that what can be achieved is obtained.

According to the fourth aspect of the present invention, the positioning device integrates the output signal of the vibration detector to obtain the speed of the non-moving part, and integrates the speed to obtain the position of the non-moving part. Since it has an integral element and is configured to generate the vibration suppression control torque command by integrating the output signal of the vibration detector using the output of each integral element, it is possible to directly detect the vibration characteristics of the mechanical system, Vibration can be robustly suppressed against changes in mechanical system characteristics, and by integrating the acceleration signal, the effect of mechanical resonance in the high frequency range can be reduced, and servo gain can be increased to speed up and enhance the positioning device. .

According to the fifth aspect of the present invention, the positioning device displays a plurality of expected mechanical vibration frequencies and vibration modes of the mechanical system on the display unit, and suppresses vibration according to the designation input according to the display. Since the vibration suppression control gain used when generating the control torque command is determined and the control device that supplies the vibration suppression control gain to the vibration suppression controller is configured, the operation of the vibration suppression controller can be confirmed on site and the machine The controller can be set according to the characteristics, and the servo gain can be increased to speed up and enhance the positioning device.

According to the sixth aspect of the present invention, the positioning device is a device for outputting a position command signal, in which the torque generating means is vibrated to vibrate the mechanical system and the position detector and the rotation angle detector are operated. Control that estimates the natural frequency and natural mode of the mechanical system from the output, determines the vibration suppression control gain used when generating the vibration suppression control torque command based on the estimation result, and supplies the vibration suppression control gain to the vibration suppression controller Since the device is configured to include the device, it is possible to obtain a positioning device that does not require manual setting of control parameters and is easy to maintain.

According to the seventh aspect of the present invention, the positioning device is configured to determine the abnormal part of the mechanical system based on the natural frequency estimated by the control device. Therefore, the defective part of the mechanical system can be easily identified. There is an effect that can be judged.

According to the invention of claim 8, in the positioning device, the vibration detector and the cable from the vibration detector to the vibration suppression controller are arranged inside the non-movable part. There is an effect that it is possible to obtain a positioning device having a vibration suppression controller that is capable of avoiding human vibration detectors and contact with the signal lines of the vibration detectors and that is excellent in reliability and noise performance.

According to the ninth aspect of the invention, the positioning device calculates the relative position of the detection position of the movable portion from the motor shaft rotation angle and the relative speed of the detection position of the movable portion with respect to the motor shaft angular velocity, and calculates them. Since it is configured to include a vibration suppression controller that generates a vibration suppression control torque command that is added to the motor torque command, it is possible to independently and stably adjust multiple machine resonances without using a vibration detector. ,
There is an effect that one that can significantly increase the feedback gain is obtained.

According to the tenth aspect of the invention, in the positioning device, in order to remove the low frequency component of the signal representing the vibration suppression control torque command generated by the vibration suppression controller, the break point frequency is the frequency at which the vibration is to be suppressed. Since it is configured to include a filter means configured to be lower than the band,
It is possible to independently stabilize and adjust a plurality of mechanical resonances without using a vibration detector, and to significantly improve the feedback gain without impairing the positioning accuracy improvement effect of the position detection signal. effective.

According to the eleventh aspect of the present invention, the torque generating means of the positioning device uses the AC servo motor and the angle from the rotation angle detector provided for positioning as a current command to the AC servo motor. It is possible to add damping to multiple machine resonances by increasing the servo gain by increasing the speed of the positioning device.
In addition to being sophisticated, there is an effect that neither the rotation angle detector for vibration suppression nor the rotation angle detector for creating a current command is required, and the positioning device can have high performance at low cost.

According to the twelfth aspect of the present invention, the positioning device uses the vibration suppression control torque command added to the motor torque command by using the relative position from the rotation angle of the detected position and the relative speed with respect to the angular velocity of the detected position. A vibration suppression controller for generating and a vertical vibration suppression controller for generating a vibration suppression control torque command to be added to the vertical motor torque command for the vertical torque generation means by using the relative position and the relative speed. With this configuration, there is an effect that the servo gain of the vertical drive system is also increased and the positioning device can be speeded up and sophisticated.

According to the thirteenth aspect of the invention, the positioner estimates the position and speed of the non-movable part by using the observer based on the motion analysis model of the mechanical system, and outputs the output of the position detector and the estimation result by the observer. Since it is configured to include a vibration suppression controller that generates a vibration suppression control torque command that is added to the motor torque command, it is possible to estimate the total state quantity of the mechanical system without increasing the number of detectors, and at low cost. Vibration can be suppressed, and by increasing the servo gain, it is possible to achieve high speed and sophistication.

According to the fourteenth aspect of the present invention, in the positioning device, the vibration suppression controller is configured to be housed in the removable card in the main body. Therefore, even when the removable card is not provided, positioning control is performed. Servo amplifier operation is possible, and when a removable card is installed, vibration suppression control can be performed, and vibration suppression control can be performed while using a standard servo amplifier. There is an effect that what can be achieved is obtained.

According to the fifteenth aspect of the present invention, in the positioning device, the leveling bolt is configured to be fitted into the bed through the spacer at a position higher than the lower surface of the bed. The vibration energy can be converted into the rigid motion of the entire device, the instability of mechanical resonance can be reduced, the servo gain can be increased, and the speed and sophistication can be increased.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a positioning device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a mechanical system in the embodiment shown in FIG.

3 is a block diagram showing a vibration detection system in the embodiment shown in FIG.

FIG. 4 is a block diagram showing a vibration suppression controller in the embodiment shown in FIG.

5 is a schematic diagram showing a model of a mechanical system in the embodiment shown in FIG.

6 is a flowchart showing an operation of the vibration suppression controller shown in FIG.

FIG. 7 is an explanatory diagram showing a matrix of a state equation of a mechanical system in an embodiment of the positioning device according to the present invention.

FIG. 8 is a Bode diagram showing a result obtained by simulating the operation state of the vibration suppression control according to the second embodiment of the present invention.

FIG. 9 is a flowchart showing the operation of the processor of the numerical controller in one embodiment of the positioning device according to the present invention.

FIG. 10 is a flowchart showing an automatic setting operation of the controller and an automatic diagnosis operation of the mechanical system in the embodiment of the positioning apparatus according to the present invention.

FIG. 11 is a sectional view showing a mounting state of the vibration detector in the embodiment of the positioning device according to the present invention.

FIG. 12 is a block diagram showing a vibration suppression controller in an embodiment of a positioning device according to the present invention.

13 is a flowchart showing a process of the vibration suppression controller shown in FIG.

FIG. 14 is a Bode diagram showing experimental results of the vibration suppression controller shown in FIG.

FIG. 15 is a flowchart showing another example of the operation of the vibration suppression control in the embodiment of the positioning device according to the present invention.

FIG. 16 is a block diagram showing a vibration suppression controller in an embodiment of the positioning device according to the present invention.

17 is a block diagram showing a transfer characteristic of a high-pass filter of the vibration suppression controller shown in FIG.

18 is a flowchart showing a process of a high pass filter of the vibration suppression controller shown in FIG.

FIG. 19 is a graph showing an experimental result of the high pass filter of the vibration suppression controller shown in FIG.

20 is a graph showing a simulation result of the vibration suppression controller shown in FIG.

FIG. 21 is a diagram showing a perfect circle accuracy actual measurement test result of the processing machine positioning table by the vibration suppression controller shown in FIG. 16;

22 is a diagram showing a machining test result when the vibration suppression controller shown in FIG. 16 is applied to a die-sinking electric discharge machine.

FIG. 23 is a block diagram showing a configuration of torque generating means in an embodiment of the positioning device according to the present invention.

FIG. 24 is a block diagram showing the configuration of a current controller in one embodiment of the positioning device according to the present invention.

FIG. 25 is a flow chart showing processing of a current controller in one embodiment of the positioning device according to the present invention.

FIG. 26 is a block diagram showing the configuration of an observer in one embodiment of the positioning device according to the present invention.

FIG. 27 is a front view showing the overall configuration of a servo amplifier in one embodiment of the positioning device according to the present invention.

FIG. 28 is a side view showing the overall configuration of a servo amplifier in one embodiment of the positioning device according to the present invention.

FIG. 29 is a front view showing a leveling bolt portion in one embodiment of the positioning device according to the present invention.

30 is a cross-sectional view taken along the line AA of the one shown in FIG.

31A and 31B are a front view and a top view showing a spacer in an embodiment of a positioning device according to the present invention.

FIG. 32 is a front view showing the overall configuration of a conventional positioning device.

FIG. 33 is a side view showing the overall configuration of a conventional positioning device.

FIG. 34 is a configuration diagram showing a leveling unit of a conventional positioning device.

FIG. 35 is a configuration diagram showing a system of a conventional positioning device.

FIG. 36 is a block diagram of a control system based on control parameters of a conventional positioning device.

FIG. 37 is a diagram schematically showing frequency transfer characteristics of a positioning control system of a conventional positioning device.

FIG. 38 is a block diagram of a conventional positioning device.

FIG. 39 is a block diagram showing a positioning device using conventional mode control.

FIG. 40 is an overall perspective view showing a conventional positioning device.

FIG. 41 is a configuration diagram of a transmission mirror system of a conventional positioning device.

FIG. 42 is a block diagram showing a control system of a conventional positioning device.

FIG. 43 is a schematic diagram showing a motion analysis of a conventional positioning device.

FIG. 44 is a block diagram showing a dynamic characteristic measuring method of a conventional positioning device.

[Explanation of symbols]

1 head, 2 columns, 4 beds, 5 leveling bolts, 6 servomotors, 7 rotation angle detectors, 8
Numerical control device (control device), 21 position detector, 75
Servo system, 76 Mechanical system, 78 Vibration suppression controller, 12
2,124,126,128 Integrator (integral element), 1
68,174 Vibration detector, 187 High-pass filter (filter means), 196 Torque generating means, 200
Current controller, 306 Z-axis servo motor (vertical servo motor).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Atsushi Taneda 5-14 Yanda Minami, Higashi-ku, Nagoya City Mitsubishi Electric Corporation Nagoya Works (72) Inventor Toshiya Nagata 5-1-1 Yada Minami, Higashi-ku, Nagoya Mitsubishi Electric Corporation Nagoya Works (72) Inventor Takafumi Kanaya 5-14 Yanda Minami 5-chome, Higashi-ku, Nagoya City Mitsubishi Electric Corporation Nagoya Works

Claims (15)

[Claims] 1. A mechanical system having a non-movable part including a bed for supporting an object to be positioned and a column for supporting a tool and a movable part supported by the non-movable part, and a movable part including a servo motor. Torque generating means for setting the position, a position detector for detecting the position of the movable part and outputting the detected position, and a rotation angle detector for detecting the rotation angle of the motor shaft of the servo motor and outputting the angle. A velocity calculation unit that calculates a temporal change rate of the detected position from the detected position and an angular velocity from the angle; a position command signal for indicating the position of the movable unit; In a positioning device including a servo system that creates a motor torque command to the torque generating means from an angular velocity, a vibration detector that detects acceleration of the non-movable part due to vibration, and the motor. A vibration suppression control torque command to be added to the torque control command, the vibration suppression control torque command being generated based on a motion analysis model of the mechanical system using the outputs of the position detector and the vibration detector. Positioning device. 2. A ball screw connected to the motor shaft of a servomotor, wherein the kinematic analysis model connects the bed and the column by one rotating spring and one rotating dashpot relating to elastic bending deformation of the bed. Regarding the elastic deformation of the leveling portion which connects the driving side and the driven side of the ball screw by one translation spring and one translation dashpot regarding the elastic deformation of 1 and adjusts the height of the bed from the floor. The bed and the floor by one rotating spring and one rotating dashpot, or by one rotating spring, one translational spring, one rotating dashpot and one translational dashpot The vibration suppression controller is a model based on the system described above, wherein the motion solution is calculated from the output of the rotation angle detector, the output of the rotation angle detector and the output of the position detector. A means for generating the vibration suppression control torque command using the detected position calculated based on the analysis model and its time change rate, and the rotation angle and angular acceleration of the non-movable part calculated from the output of the vibration detector. The positioning device according to claim 1, wherein: 3. The ball screw connected to the motor shaft of a servomotor, wherein the motion analysis model connects the bed and the column by one rotating spring and one rotating dashpot relating to elastic bending deformation of the bed. Regarding the elastic deformation of the leveling portion which connects the driving side and the driven side of the ball screw by one translation spring and one translation dashpot regarding the elastic deformation of 1 and adjusts the height of the bed from the floor. The bed and the floor by one rotating spring and one rotating dashpot, or by one rotating spring, one translational spring, one rotating dashpot and one translational dashpot The vibration suppression controller converts the state quantity in the state equation based on the motion analysis model into the mode coordinates where the mode matrix is a real number. The positioning device according to claim 1, further comprising: a unit that generates the vibration suppression control torque command using the converted signal. 4. The vibration suppression controller integrates an output signal of the vibration detector to obtain a speed of the non-movable portion, and an integration element that integrates the speed to obtain a position of the non-movable portion. The positioning device according to claim 1, further comprising: a unit that has an element and that integrates an output signal of the vibration detector using an output of each integration element to generate the vibration suppression control torque command. . 5. A plurality of expected mechanical vibration frequencies and vibration modes of the mechanical system are displayed on a display unit, and vibration suppression control is performed when a vibration suppression control torque command is generated according to a designation input according to the display. The positioning device according to claim 1, further comprising a control device that determines a control gain and supplies the vibration suppression control gain to the vibration suppression controller. 6. A vibration is applied to the torque generating means to vibrate a mechanical system, and a natural frequency and a natural mode of the mechanical system are estimated from outputs of the position detector and the rotation angle detector, and an estimation result is obtained. The positioning device according to claim 1, further comprising: a control device that determines a vibration suppression control gain used when generating the vibration suppression control torque command based on the above, and supplies the vibration suppression control gain to the vibration suppression controller. . 7. The positioning device according to claim 6, wherein the control device includes means for determining an abnormal part of a mechanical system based on the estimated natural frequency. 8. The vibration detector and the cable extending from the vibration detector to the vibration suppression controller are installed inside a non-movable part.
The positioning device according to claim 1. 9. A mechanical system having a non-movable portion including a bed for supporting an object to be positioned and a column for supporting a tool, a movable portion supported by the non-movable portion, and a movable portion including a servo motor. Torque generating means for setting the position, a position detector for detecting the position of the movable part and outputting the detected position, and a rotation angle detector for detecting the rotation angle of the motor shaft of the servo motor and outputting the angle. A velocity calculation unit that calculates a temporal change rate of the detected position from the detected position and an angular velocity from the angle; a position command signal for indicating the position of the movable unit; In a positioning device including a servo system that creates a motor torque command from the angular velocity to the torque generating means, a relative position from the rotation angle of the detection position and the angle of the detection position. A vibration suppression control torque command, which is calculated by using the detected position, the rate of change, the angle, and the angular velocity, and is added to the motor torque command by using the calculated relative position and relative velocity. A positioning device comprising a vibration suppression controller for generating 10. The break point frequency is configured to be lower than a frequency band in which vibration is to be suppressed in order to remove a low frequency component of a signal representing the vibration suppression control torque command generated by the vibration suppression controller. Positioning device according to claim 9, characterized in that it comprises filter means. 11. The servo motor is an AC servo motor, and the torque generating means utilizes the AC servo motor and an angle from a rotation angle detector provided for positioning to make a current to the AC servo motor. The positioning device according to any one of claims 1 to 10, further comprising a current controller that generates a command. 12. A mechanical system having a non-movable part including a bed for supporting an object to be positioned and a column for supporting a tool, and a movable part supported by the non-movable part, and a vertical direction toward the object to be positioned. A vertical torque generating unit that includes a moving head and a vertical servomotor that drives the head to set the head to a desired position; and a torque generating unit that includes a servomotor to set the movable unit to a desired position. A position detector that detects the position of the movable portion and outputs the detected position; a rotation angle detector that detects the rotation angle of the motor shaft of the servo motor and outputs the angle; A velocity calculation unit that calculates an angular velocity from the angle while calculating a rate of change with time, a position command signal for indicating the position of the movable unit, and the detected position and the angle that have been fed back. In a positioning device including a servo system that creates a motor torque command from the speed to the torque generation means, by using a relative position from the rotation angle of the detection position and a relative speed with respect to the angular velocity of the detection position, Vibration suppression control that adds a vibration suppression control torque command that is added to the motor torque command, and vibration that is added to the vertical direction motor torque command for the vertical direction torque generation means using the relative position and the relative speed. A positioning device, comprising: a vertical vibration suppression controller that generates a suppression control torque command. 13. A mechanical system having a non-movable part including a bed for supporting an object to be positioned and a column for supporting a tool, a movable part supported by the non-movable part, and a movable part including a servo motor. Torque generating means for setting the position, a position detector for detecting the position of the movable part and outputting the detected position, and a rotation angle detector for detecting the rotation angle of the motor shaft of the servo motor and outputting the angle. A velocity calculation unit that calculates a temporal change rate of the detected position from the detected position and an angular velocity from the angle; a position command signal for indicating the position of the movable unit; In a positioning device including a servo system that creates a motor torque command from the angular velocity to the torque generating means, an observer based on a motion analysis model of the mechanical system is used to perform the non-operation. A vibration suppression controller that estimates the position and speed of the moving part and uses the output of the position detector and the estimation result by the observer to generate a vibration suppression control torque command to be added to the motor torque command is provided. Positioning device characterized by the above. 14. The vibration suppression controller is housed in a card which can be attached to and detached from the main body.
Alternatively, the positioning device according to claim 13. 15. A mechanical system having a non-movable part including a bed for supporting an object to be positioned and a column for supporting a tool, and a movable part supported by the non-movable part, and a height of the bed from the floor is adjusted. A leveling bolt, a torque generating means including a servo motor for setting the movable part at a desired position, a position detector for detecting the position of the movable part and outputting a detected position, and a motor shaft of the servo motor. A rotation angle detector that detects a rotation angle and outputs the angle, a speed calculation unit that calculates the time change rate of the detection position from the detection position and an angular velocity from the angle, and indicates the position of the movable unit. And a servo system that creates a motor torque command to the torque generating means from the detected position and the angular velocity that are fed back. The belling bolt is fitted to the bed via a spacer at a position higher than the lower surface of the bed.