KR20220115352A - Resonance suppression control system of machine tool and method thereof - Google Patents

Abstract

The present invention relates to a resonance suppression control system of a machine tool and a control method thereof. In accordance with the present invention, a pulsation component of a sub motor part calculated from the sub motor part in real time is reflected to change a d-axis feedback current fed back to a main motor part in real time to perform tandem control in a current loop, which is not a speed loop, on resonance suppression through tandem control in accordance with the operation of a servo motor part, thereby increasing system responsiveness, and resonance suppression occurring when two servo motors are operated in parallel through one single power conversion part and one single servo drive is accurately automatically controlled through the tandem control, thereby improving the stability and reliability of a machine tool, reducing costs for manufacture and maintenance and promoting miniaturization.

Description

Resonance suppression control system of machine tool and control method thereof

The present invention relates to a resonance suppression control system for a machine tool and a control method thereof, and more particularly, to reflect the pulsation component of the auxiliary motor unit calculated in real time from the auxiliary motor unit to reflect the d-axis feedback current fed back to the main motor unit in real time. By changing the resonance suppression through tandem control according to the operation of the servomotor unit, the system responsiveness is improved by performing tandem control in the current loop instead of the speed loop, and two servomotors are paralleled with one power conversion unit and one servo drive. A resonance suppression control system for machine tools that can improve the stability and reliability of machine tools, reduce manufacturing and maintenance costs, and promote miniaturization by automatically and quickly and accurately controlling resonance suppression that occurs during operation through tandem control; and It relates to a control method thereof.

In general, a machine tool refers to a machine used for the purpose of machining a metal/non-metal workpiece into a desired shape and size using an appropriate tool by various cutting or non-cutting methods.

Various types of machine tools, including turning centers, vertical/horizontal machining centers, door machining centers, Swiss turns, electric discharge machines, horizontal NC boring machines, CNC lathes, etc., are widely used in various industrial sites for their respective purposes.

In general, various types of machine tools currently used have an operation panel to which a numerical control (NC) or computerized numerical control (CNC) technology is applied. Such an operation panel is provided with various function switches or buttons and a monitor.

In addition, the machine tool is a table on which a workpiece material is seated and transferred for processing the workpiece, a pallet for preparing the workpiece before processing, a spindle that rotates with a tool or workpiece combined, a tailstock for supporting the workpiece, etc. during processing, a vibration isolator etc. are provided.

In general, in a machine tool, a table, a tool rest, a main shaft, a tailstock, a vibration isolator, etc. are provided with a conveying unit conveying along a conveying axis in order to perform various machining.

In addition, in general, a machine tool uses a plurality of tools for various processing, and a tool magazine or a turret is used in the form of a tool storage place for storing and storing a plurality of tools.

In addition, in general, a machine tool is provided with an automatic tool changer (ATC, Automatic Tool Changer) for withdrawing or receiving a specific tool from the tool magazine by the command of the numerical control unit in order to improve the productivity of the machine tool.

In addition, in general, a machine tool is provided with an automatic pallet changer (APC, Automatic Palette Changer) in order to minimize the non-working time. The automatic pallet changer (APC) automatically exchanges pallets between the workpiece machining area and the workpiece installation area. Pallets may be loaded with workpieces.

In general, a servo motor is used to drive an automatic tool changer (ATC), an automatic pallet changer (APC), a tailstock, or a vibration isolator in a machine tool.

As such, a device that controls the servo motor and finally controls the automatic tool changer (ATC), the automatic pallet changer (APC), the tailstock, or the vibration isolator is referred to as a servo controller.

In particular, when a large size or a large force is required, such as a large automatic pallet changer (APC), two servomotors can be installed in parallel due to productivity and economic factors and technical factors that cannot obtain sufficient torque with only one servomotor. One axis is driven by driving, and this is called tandem control.

However, as shown in FIG. 1, in the case of using two conventional servo motors, in the conventional servo control apparatus, one inverter and one servo drive are coupled to one servo motor, respectively. That is, the first inverter 20 and the first servo drive 10 are connected to the first servo motor 30 , and the second inverter 21 and the second servo drive 11 are connected to the second servo motor 31 . It was operated as a multi-inverter multi servo motor connected.

However, in the case of multi-inverter multi-servo motors, since a separate inverter and servo drive must be combined for each servo motor, the size of the device increases, manufacturing and maintenance costs increase, and the machine tool cannot be miniaturized. there was.

In order to solve this problem, as shown in FIG. 2, a single inverter dual servomotor (Single inverter) of a method in which one inverter 20 and one servo drive 10 are operated in parallel to two servo motors 30 and 31 dual servo motor, SIDM) has been proposed.

However, unlike induction motors in which slip exists, servo motors are permanent magnet type synchronous motors. Stable parallel operation is possible only when two servo motors are synchronized so that there is no speed deviation because there is no slip. There was a problem in that the stability and reliability of the control device was lowered, and finally, the stability and reliability and processing precision of the machine tool were lowered.

In order to solve the resonance suppression control problem, three conventional resonance suppression control systems and resonance suppression control methods have been proposed.

First, a damping control device and method using an auxiliary inverter and an auxiliary winding. This is a structure in which the main inverter and the auxiliary inverter are separately provided, and the servo motor and the auxiliary winding are formed. Problems such as production difficulties still remain.

Second, as the active damping control device and method simply set the resonance suppression control in an empirical way, the reliability and stability of the servo control device are still guaranteed because it cannot actively cope with the actual resonance occurrence or many disturbances or variables. There is a problem in that only the manufacturing cost increases.

Third, the resonance suppression control is calculated in an empirical way with a pulsation reduction device and method using a load oscillation analyzer. There is a problem in that the accuracy and reliability of the resonance suppression control are reduced as the calculation is performed simply by an empirical method, and ultimately, the machining precision and reliability of the machine tool are reduced.

In addition, Korean Patent Application Laid-Open No. 10-2020-0025683 discloses that the control gain is adjusted by checking the phase margin in the Bode Plot obtained through frequency analysis, and the Korean Patent Application No. 10-2019- No. 0170546 finds a resonant frequency and applies a notch filter to the frequency. As both tandem controls perform speed loop control, the responsiveness of the system is lowered and the system parameters are weak.

Therefore, regardless of the capacity or type of the servomotor, control is performed in the current loop rather than in the speed loop, thereby improving the system responsiveness and improving accuracy and reliability while having robust characteristics against changes in system parameters. It is urgent to develop a resonance suppression system and its control method in tandem control of a machine tool using a load pulsation analyzer so as to reduce manufacturing and maintenance costs while promoting miniaturization and automation and improving operator convenience. to be.

Korean Patent Publication No. 10-2020-0025683 Republic of Korea Patent Application No. 10-2019-0170546 Korean Patent Laid-Open Publication No. 10-1996-0001940 Korean Patent Publication No. 10-1995-0703812

The present invention is to solve the above problems, and an object of the present invention is to reflect the pulsation component of the auxiliary motor unit calculated in real time from the auxiliary motor unit and change the d-axis feedback current fed back to the main motor unit in real time to change the main motor unit As it is automatically and quickly and accurately performed through resonance suppression through tandem control according to the operation of the servomotor and servomotor unit, stable setting and operation regardless of the type, capacity, or system parameters of the servomotor for the convenience of the operator and finally Reduces manufacturing cost by controlling servo motor-driven devices such as automatic tool changer or automatic pallet changer, eliminates unnecessary equipment to minimize it, promotes miniaturization, and improves reliability and durability by reducing noise An object of the present invention is to provide a resonance suppression control system of a machine tool and a control method thereof.

In addition, another object of the present invention is to convert the current measured by the measuring unit in real time to the d-q axis current of the main motor unit and the servo motor unit, which varies in real time depending on the operating state of the servo motor unit according to the tandem control of the servo drive. By comparison, the main motor unit and the servo motor unit are selected, and the corrected d-axis feedback current is transmitted to the main motor unit in real time according to the result of the calculation unit of the d-axis current control unit, and the corrected d-axis feedback current of the main motor unit is fed back to the main motor unit In this state, as the d-axis current of the main motor is controlled, resonance suppression is automatically performed in real time through tandem control of the main and auxiliary motors, so that all speeds and positions of the two servomotors, the main and auxiliary motors, are synchronized. By performing tandem control in the current loop, not the speed loop, the resonance suppression is performed regardless of the type of servo motor part through precise tandem control, which increases system responsiveness and possesses robust characteristics against system parameter changes, making it an automatic tool changer or automatic tool changer. To provide a machine tool resonance suppression control system and its control method that can maximize the servo control precision, reliability and stability of the pallet changer and reduce maintenance costs.

In order to achieve the object of the present invention, the resonance suppression control system of the machine tool according to the present invention is a numerical control unit; main work unit; PLC for executing a control command through communication with the numerical control unit or the main operation unit; a servo drive that executes a control command of the PLC; a servo motor unit having a main motor unit and an auxiliary motor unit connected in parallel to each other, and driven through tandem control of the servo drive; and a power conversion unit electrically connected to the servo motor unit and the servo drive to apply a current to the servo motor unit, wherein the main motor unit and the auxiliary motor unit of the servo motor unit are for tandem control of the servo drive. The servo drive changes in real time according to the operating state of the servo motor unit, and the servo drive reflects the pulsation component of the auxiliary motor unit calculated in real time from the auxiliary motor unit to change the d-axis feedback current fed back to the main motor unit in real time Thus, resonance suppression according to the operation of the servomotor unit can be automatically performed.

In addition, in another preferred embodiment of the resonance suppression control system of the machine tool according to the present invention, the servo drive of the resonance suppression control system of the machine tool includes a measuring unit for measuring the current of the main motor unit and the auxiliary motor unit in real time; a coordinate conversion unit for converting the current value measured by the measuring unit into d-q coordinates; a selection unit selecting the main motor unit and the auxiliary motor unit which are changed in real time by comparing the d-axis current values converted through the coordinate conversion unit; and d-axis for tandem control of the main motor unit and the auxiliary motor unit by correcting in real time a d-axis feedback current fed back to the main motor unit in which the pulsation component of the auxiliary motor unit, which changes in real time according to the selection result of the selection unit is reflected, is corrected in real time It may include a current control unit.

In addition, in another preferred embodiment of the resonance suppression control system of the machine tool according to the present invention, the d-axis current control unit of the resonance suppression control system of the machine tool suppresses the resonance generated during parallel operation of the main motor unit and the auxiliary motor unit. a storage unit for storing information for tandem control for suppression; and a calculation unit for calculating a d-axis feedback current fed back to the main motor unit based on the selection result of the selection unit and the information stored in the storage unit.

In addition, in another preferred embodiment of the resonance suppression control system of the machine tool according to the present invention, the d-axis current control unit of the resonance suppression control system of the machine tool according to the results of the selection unit and the calculation unit in real time to the main motor unit Transmitting the corrected d-axis feedback current, and controlling the d-axis current of the main motor part in a state in which the corrected d-axis feedback current of the main motor part is fed back to the main motor part, tandem control of the main motor part and the auxiliary motor part It may further include; a processing unit that performs resonance suppression in real time.

Further, in another preferred embodiment of the resonance suppression control system of the machine tool according to the present invention, the storage unit of the d-axis current control unit of the resonance suppression control system of the machine tool is the motor pole constant, the magnetic flux of the permanent magnet, the resistance of the motor stator winding , a basic data storage unit for storing information about the inductance of the stator winding of the motor, the rotor angular velocity, the rotor position error between the main motor unit and the auxiliary motor unit, and the low-pass filter; a feedback data storage unit for storing feedback information on positions, speeds, d-axis currents, and q-axis currents of the main motor unit and the auxiliary motor unit generated during parallel operation of the main motor unit and the auxiliary motor unit; and a real-time data storage unit configured to store the results of the measurement unit, the selection unit, and the calculation unit in real time.

In addition, in another preferred embodiment of the resonance suppression control system of the machine tool according to the present invention, the calculation unit of the d-axis current control unit of the resonance suppression control system of the machine tool is the d-axis of the auxiliary motor unit converted by the coordinate conversion unit. a DC offset component calculating unit for calculating a d-axis DC offset component of the auxiliary motor unit based on a current value, a selection result of the selection unit, and information stored in the storage unit; The d-axis pulsation component of the auxiliary motor unit by the d-axis current value of the auxiliary motor unit converted by the coordinate conversion unit, the selection result of the selection unit, information stored in the storage unit, and the calculated value of the DC offset component calculation unit a pulsation component calculation unit to calculate; and the selection result of the selection unit, the d-axis current value of the main motor unit converted by the coordinate conversion unit, the information stored in the storage unit, the calculated value of the DC offset component calculation unit, and the calculated value of the pulsation component calculation unit. and a d-axis feedback current calculator for calculating the d-axis feedback current of the main motor unit.

In addition, in another preferred embodiment of the resonance suppression control system of the machine tool according to the present invention, the DC offset component calculation unit of the d-axis current control unit of the resonance suppression control system of the machine tool is the auxiliary motor converted by the coordinate conversion unit By filtering the negative d-axis current value with a low-pass filter, the d-axis DC offset component of the auxiliary motor unit may be extracted and calculated.

In addition, in another preferred embodiment of the resonance suppression control system of the machine tool according to the present invention, the d-axis current control unit of the resonance suppression control system of the machine tool is fed back to the main motor unit in real time through the d-axis feedback current calculation unit By controlling the d-axis feedback current of the main motor unit to 0, resonance suppression may be performed by tandem control of the main motor unit and the auxiliary motor unit through pulsation reduction of the auxiliary motor unit.

In order to achieve another object of the present invention, the resonance suppression control method of a machine tool according to the present invention stores basic data information for tandem control of a servo motor unit including a main motor unit and an auxiliary motor unit connected in parallel to each other. to do; performing a control command in the PLC through communication with a numerical control unit or a main operation unit; executing the control command transmitted from the PLC in the servo drive; applying a current to the servo motor unit by the power conversion unit according to the signal of the servo drive; Storing feedback information about the position, speed, d-axis current, and q-axis current of the main motor unit and the auxiliary motor unit generated during parallel operation of the main motor unit and the auxiliary motor unit; measuring the current of the main motor unit and the auxiliary motor unit; converting the measured current value into d-q coordinates; comparing the converted d-axis current values with each other and selecting the main motor unit and the auxiliary motor unit which are changed in real time; calculating a d-axis DC offset component of the auxiliary motor unit; calculating a d-axis pulsation component of the auxiliary motor unit based on the DC offset component calculated value; calculating a d-axis feedback current of the main motor unit based on the converted d-axis current value of the main motor unit, the DC offset component calculated value, and the pulsation component calculated value; and performing d-axis current control of the main motor unit with the calculated d-axis feedback current, wherein the main motor unit and the auxiliary motor unit are changed in real time according to the operating state of the servo motor unit, and the auxiliary motor unit By reflecting the pulsation component of the auxiliary motor unit calculated in real time from the d-axis feedback current fed back to the main motor unit in real time, resonance suppression according to the operation of the servo motor unit may be automatically performed.

In addition, in another preferred embodiment of the resonance suppression control method of the machine tool according to the present invention, the resonance suppression control method of the machine tool after performing the d-axis current control of the main motor unit, the main motor unit and the auxiliary motor The method may further include; as a result of negative selection, storing the DC offset component calculated value, the pulsation component calculated value, and the d-axis feedback current value in real time.

The resonance suppression control system of a machine tool and a control method thereof according to the present invention reflect the pulsation component of the auxiliary motor unit calculated in real time from the auxiliary motor unit and change the d-axis feedback current fed back to the main motor unit in real time, thereby changing the main motor unit and the servo As it is automatically and quickly and accurately performed through resonance suppression through tandem control according to the operation of the motor unit, regardless of the type, capacity, or system parameters of the servomotor, it is stably set and operated for the convenience of the operator. By controlling devices driven by servo motors such as tool changers or automatic pallet changers, manufacturing cost is reduced, reliability is improved by noise reduction, and can be used universally regardless of the type and capacity of servo motor. There is an effect that can increase the compatibility of the resonance suppression control system of the machine and its control method.

In addition, the resonance suppression control system of the machine tool and the control method thereof according to the present invention is an auxiliary motor that calculates resonance generated when two servo motors are operated in parallel by one power unit and a power conversion unit in real time from the auxiliary motor unit. By changing the d-axis feedback current fed back to the main motor unit in real time by reflecting the pulsation component of the motor unit, resonance suppression through tandem control according to the operation of the servo motor unit. This has the effect of reducing the size of the machine tool and the tandem control system of the machine tool and maximizing the space utilization.

Furthermore, the resonance suppression control system of the machine tool and the control method thereof according to the present invention are the main motor unit and the servo motor unit that change in real time according to the operating state of the servo motor unit according to the tandem control of the servo drive. is converted into d-q-axis current, compared with each other to select the main motor unit and the servo motor unit, and according to the result of the calculation unit of the d-axis current control unit, the corrected d-axis feedback current is transmitted to the main motor unit in real time, and the corrected main motor unit d As the d-axis current of the main motor is controlled while the axis feedback current is fed back to the main motor, resonance suppression is automatically performed in real time through tandem control of the main and auxiliary motors. Through precise tandem control synchronized at all speeds and positions of the motor unit, resonance suppression is performed regardless of the type of servo motor unit, and tandem control is performed in the current loop, not the speed loop, thereby improving system responsiveness and providing robustness to system parameter changes. There is an effect of maximizing the precision and reliability of the servo control device of the automatic tool changing device or the automatic pallet changing device, and increasing the stability and processing efficiency of the machine tool.

In addition, the resonance suppression control system of the machine tool and the control method thereof according to the present invention can reduce the resonance generated when two servo motors are operated in parallel by one power unit and a power conversion unit regardless of the type and capacity of the servo motor. As the tandem control is automatically performed in the current loop instead of the speed loop in real time, operator convenience is promoted, and the non-working time is minimized, thereby maximizing the productivity of the machine tool.

1 shows a conceptual diagram of a multi-inverter multi-servo motor in which one inverter and one servo drive are coupled to one conventional servo motor.
2 is a conceptual diagram of a single inverter multi-servo motor in which tandem control is performed by combining one inverter and one servo drive with two conventional servo motors.
3 shows the abc coordinate system of a servomotor having a three-phase power supply.
FIG. 4 shows a state in which the abc coordinate system shown in FIG. 3 is converted into a dq coordinate system by a coordinate conversion unit into dq coordinates.
Figure 5 shows a block diagram of the configuration of the resonance suppression control system of the machine tool according to an embodiment of the present invention.
6 is a block diagram showing the configuration of the d-axis current control unit of the servo drive of the resonance suppression control system of the machine tool according to an embodiment of the present invention.
7 is a flowchart illustrating a resonance suppression control method of a machine tool according to an embodiment of the present invention.
8 to 9 are graphs for explaining the resonance suppression effect according to the tandem control through the d-axis current control of the main motor unit by the resonance suppression control system and the control method of the machine tool according to an embodiment of the present invention.

Hereinafter, with reference to the drawings of the resonance suppression control system and the control method of the machine tool according to an embodiment of the present invention will be described in detail. The embodiments introduced below are provided as examples so that the spirit of the present invention can be sufficiently conveyed to those skilled in the art. Accordingly, the present invention is not limited to the embodiments described below and may be embodied in other forms. And, in the drawings, the size and thickness of the device may be exaggerated for convenience. Like reference numbers refer to like elements throughout.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout. The sizes and relative sizes of layers and regions in the drawings may be exaggerated for clarity of description.

The terminology used herein is for the purpose of describing the embodiments, and therefore is not intended to limit the present invention. In this specification, the singular also includes the plural, unless specifically stated otherwise in the phrase. As used herein, “comprise” and/or “comprising” refers to the presence of one or more other components, steps, operations and/or elements mentioned. or addition is not excluded.

3 shows the abc coordinate system of a servomotor having a three-phase power supply, and FIG. 4 shows a state in which the abc coordinate system shown in FIG. 3 is converted into a d-q coordinate system by a coordinate conversion unit into d-q coordinates. Figure 5 shows a block diagram of the configuration of the resonance suppression control system of the machine tool according to an embodiment of the present invention, Figure 6 is a servo drive of the resonance suppression control system of the machine tool according to an embodiment of the present invention d A block diagram of the configuration of the axial current control unit is shown. 7 is a flowchart illustrating a resonance suppression control method of a machine tool according to an embodiment of the present invention. 8 to 9 are graphs for explaining the resonance suppression effect according to the tandem control through the d-axis current control of the main motor unit by the resonance suppression control system and the control method of the machine tool according to an embodiment of the present invention.

A resonance suppression control system 1 of a machine tool according to the present invention will be described with reference to FIGS. 3 to 6 . 5 and 6, the resonance suppression control system 1 of a machine tool according to an embodiment of the present invention includes a numerical control unit 100, a main operation unit 200, a PLC 300, and a servo drive 400. ), a servo motor unit 600 , and a power conversion unit 500 .

The numerical control unit 100 includes a numerical control (NC) or a computerized numerical control (CNC), and various numerical control programs are built-in. That is, the numerical control unit 100 has a built-in servo motor driving program, a tool operation program, and the like, and the corresponding program is automatically loaded and operated according to the driving of the numerical control unit. In addition, the numerical control unit 100 communicates with the main operation unit 200 , the PLC 300 , and the servo drive 400 by a predetermined protocol.

In addition, the numerical control unit 100 is a main motor unit (M2, Master motor) and / Alternatively, feedback information is received from the auxiliary motor unit (M1, slave motor). More specifically, the numerical control unit 100 receives feedback information about the position and speed of the main motor unit or the auxiliary motor unit, the d-axis current, and the q-axis current from the feedback data storage unit of the storage unit of the d-axis current control unit to be described later.

The main operation unit 200 includes a screen display program and a data input program according to screen display selection, and displays a software switch on the display screen according to the output of the screen display program, and turns on/off the software switch. It recognizes and executes the function of issuing input/output commands for machine operation.

In addition, although not necessarily limited thereto, the main operation unit 200 is provided with a monitor that is installed on the housing, case, or one side of the machine tool to display various function switches or buttons and various information. That is, the monitor is a liquid crystal display (LCD), a thin film transistor-liquid crystal display (TFT LCD), an organic light-emitting diode (OLED), a flexible display (flexible display) , a three-dimensional display (3D display), and at least one of an e-ink display (e-ink display), and may be formed in the form of a touch screen.

PLC (Programmable Logic Controller, 300) performs communication according to a predetermined protocol with the numerical control unit 100 or the main operation unit 200, and performs a function of executing a control command through such communication. That is, the PLC 300 operates by receiving a control command according to the numerical control program of the numerical control unit 100 or the main operation unit 200 .

In addition, after receiving a control command from the numerical control unit 100 or the main operation unit 200 and performing it, the PLC 300 outputs it to the numerical control unit 100 , and outputs the control command to the servo drive through the main operation unit 200 . forward to (400). If necessary, the PLC 300 may transmit a real-time control command from the user to the servo drive 400 through the main operation unit 200 .

The servo drive 400 performs a control command of the PLC 300 . That is, the servo drive 400 controls the driving of the main motor unit and the auxiliary motor unit of the servo motor unit 600 to be described later through the control command of the PLC 300 , and finally the automatic driven by the main motor unit and the auxiliary motor unit. It controls the operation of various parts of machine tools such as tool changer (ATC) or automatic pallet changer (APC), tailstock, and vibration isolator. The servo drive 400 transmits the control result to the PLC 300 through a contact point or communication by a predetermined protocol.

In addition, the servo drive 400 provides feedback information from the main motor unit M2 and the auxiliary motor unit M1 of the servo motor unit 600 used for driving the automatic tool changer (ATC) or the automatic pallet changer (APC). is delivered

The servo motor unit 600 is driven through tandem control of the servo drive 400 . 5, the servo motor unit 600 of the resonance suppression control system 1 of the machine tool according to an embodiment of the present invention includes a main motor unit M2 and an auxiliary motor unit M1 connected in parallel to each other. With a, both the main motor unit and the auxiliary motor unit is formed of a servo motor (servo motor). In addition, the main motor unit and the auxiliary motor unit are changed in real time according to the operating state of the servo motor unit according to the tandem control of the servo drive. That is, the main motor unit and the auxiliary motor unit are not specifically designated, but are connected in parallel to each other according to the tandem control of the servo drive and are changed in real time according to the load amount, which is the operating state of the main motor unit and the auxiliary motor unit driven through synchronization. For example, a side receiving a large load becomes a main motor unit, and a side receiving a relatively small load becomes an auxiliary motor unit, and tandem control for suppressing resonance is performed.

The power conversion unit 500 is electrically connected to the servo motor unit 600 and the servo drive 400 . In addition, the power conversion unit 500 applies a current to the servo motor unit 600 according to the contact signal of the servo drive 400 . Specifically, the servo drive reflects the pulsation component of the auxiliary motor unit calculated in real time from the auxiliary motor unit and changes the d-axis feedback current fed back to the main motor unit in real time to apply the current to the servo motor unit through the power conversion unit, and accordingly Resonance suppression according to the operation of the servo motor is automatically performed.

As such, the resonance suppression control system of the machine tool according to the present invention reflects the pulsation component of the auxiliary motor unit calculated in real time from the auxiliary motor unit and changes the d-axis feedback current fed back to the main motor unit in real time, thereby changing the main motor unit and the servo motor unit. As it is automatically and quickly and accurately performed through resonance suppression through tandem control according to operation, regardless of the type, capacity, or system parameters of the servomotor, it is stably set and operated for operator convenience, and finally automatic tool exchange By controlling a device driven by a servo motor, such as a device or an automatic pallet changer, manufacturing cost is reduced, reliability is improved by noise reduction, and can be used universally regardless of the type and capacity of the servo motor. It is possible to increase the compatibility of the resonance suppression control system and its control method.

As shown in FIG. 5 , the servo drive 400 of the resonance suppression control system 1 of the machine tool according to an embodiment of the present invention includes a measuring unit 410 , a coordinate converting unit 420 , and a selection unit 430 . , and a d-axis current control unit 440 .

Although not shown in the drawings, the servo drive 400 of the resonance suppression control system of the machine tool may further include a controller if necessary. Such a controller is installed inside the servo drive 400, and a detailed control command decoding program, various processing programs, and driving programs are separately built in. In addition, the controller performs communication with the numerical control unit 100 , the main operation unit 200 , the PLC 300 , the servo motor unit 600 , and the power conversion unit 500 by a predetermined protocol.

If necessary, the main operation unit 200 may directly transmit the control command of the main operation unit to the servo drive 400 through the PLC 300 without going through the numerical control unit 100 .

As such, since the detailed control command decoding program or a separate control program are all built-in in the controller of the servo drive 400 to be described later, the main operation unit ( 200) and the servo drive 400 may execute a command through the PLC 300 to drive the servo motor unit 600, which will be described later.

Therefore, the controller of the servo drive 400 can perform detailed control commands performed by the numerical control unit 100, so that only other numerical control units and protocol functions can be programmed to perform the servo drive function. Through this, various programs can be operated, maximizing the compatibility of equipment and promoting user convenience.

The measuring unit 410 measures the current of the main motor unit and the auxiliary motor unit in real time. Such a measurement unit may calculate the current by inversely calculating the torque value of the main motor unit and the auxiliary motor unit in a sensor or a numerical control unit.

The coordinate conversion unit 420 converts the current value measured by the measurement unit into d-q coordinates. That is, the coordinate conversion unit converts the current value expressed by the measured abc coordinates of the main motor unit and the auxiliary motor unit measured by the measuring unit into d-q coordinates.

As described above, a three-phase AC motor is used for both the main motor unit and the auxiliary motor unit of the servo motor unit of the resonance suppression control system of the machine tool according to the present invention. Accordingly, in order to vector control a 3-phase AC motor, the field (magnet) magnetic flux component and the armature (coil) magnetic flux component are maintained at 90 degrees, and the field (magnet) magnetic flux component and the armature (coil) magnetic flux component can be controlled independently. Two conditions must be satisfied. As shown in FIG. 3 , two conditions for vector control cannot be satisfied in the three-phase abc coordinate system, so vector control is possible only when the abc coordinate is converted into the d-q coordinate as shown in FIG. 4 . In FIG. 3, a solid line indicates a U phase, a dashed-dotted line indicates a V phase, and a double-dashed line indicates a W phase. In the d-q coordinate system of Fig. 4, the d-axis current is a current corresponding to the field (magnet) magnetic flux component and constitutes an axis that is the basis of vector control, and the q-axis current is a current corresponding to the armature (coil) magnetic flux component and is a torque in vector control. is the axis from which

In this way, the coordinate conversion unit automatically performs the current in the abc coordinates into the d-axis current so that the vector control can be performed, thereby improving operator convenience, reducing control time and cost, and reducing the size of equipment.

The selection unit 430 selects the main motor unit and the auxiliary motor unit which are changed in real time by comparing the d-axis current values converted through the coordinate conversion unit with each other. That is, the selection unit 430 compares the d-axis current values converted through the coordinate conversion unit with each other and when the corresponding value is greater than or equal to 0, M2 becomes the main motor part and M1 becomes the auxiliary motor part, and on the contrary, the corresponding value is greater than 0 If it is small, M1 becomes the main motor part and M2 becomes the auxiliary motor part. A detailed selection principle for this will be described later.

The d-axis current control unit 440 tandemly controls the main motor unit and the auxiliary motor unit by correcting in real time the d-axis feedback current fed back to the main motor unit in which the pulsation component of the auxiliary motor unit that changes in real time according to the selection result of the selection unit is reflected in real time. .

The coordinate conversion unit 420, the selection unit 430, and the d-axis current control unit 440 are all installed inside the servo drive 400, and a detailed control command decoding program, various processing programs, and driving programs are separately built-in. can be

In addition, the measurement unit 410, the coordinate conversion unit 420, the selection unit 430, and the d-axis current control unit 440 are the numerical control unit 100, the main operation unit 200, the PLC 300, the servo motor unit ( 600), it is possible to perform communication with the power conversion unit 500 by a predetermined protocol.

Therefore, the resonance suppression control system of the machine tool according to the present invention is a pulsation component of the auxiliary motor unit that is calculated in real time from the auxiliary motor unit resonance generated when two servo motors are operated in parallel by one power unit and a power conversion unit By changing the d-axis feedback current fed back to the main motor unit in real time by reflecting and the tandem control system of machine tools can be miniaturized and the space utilization can be maximized.

5 and 6, the d-axis current control unit 440 of the servo drive 400 of the resonance suppression control system 1 of the machine tool according to an embodiment of the present invention is a storage unit 441, the calculation a unit 442 , and a processing unit 443 .

The storage unit 441 stores information for tandem control for suppressing resonance generated during parallel operation of the main motor unit and the auxiliary motor unit. The storage unit 441 may be various storage devices such as ROM, RAM, EPROM, flash drive, hard drive, and the like, and may be web storage that performs a storage function of the storage unit on the Internet. The operation of storing information for tandem control to suppress resonance occurring during parallel operation of the main motor unit and the auxiliary motor unit in the storage unit can be performed by the operator through the numerical control unit or the main operation unit, and is input to PLC or input in the form of a program. You can also save it through wealth.

The calculation unit 442 calculates the d-axis feedback current fed back to the main motor unit through the selection result of the selection unit and the information stored in the storage unit.

The processing unit 443 transmits the corrected d-axis feedback current to the main motor unit in real time according to the results of the selection unit and the calculation unit, and in a state in which the corrected d-axis feedback current of the main motor unit is fed back to the main motor unit, the d-axis of the main motor unit As the current is controlled, resonance suppression is performed in real time through tandem control of the main motor unit and the auxiliary motor unit.

The storage unit 441, the calculation unit 442, and the processing unit 443 are installed inside the d-axis current control unit 440, and a detailed control command decoding program, various processing programs, and driving programs are separately built in. can

In addition, the storage unit 441 , the calculation unit 442 , and the processing unit 443 are the numerical control unit 100 , the main operation unit 200 , the PLC 300 , the servo motor unit 600 , and the power conversion unit 500 . , the measurement unit 410 , the coordinate transformation unit 420 , and the selection unit 430 may communicate with each other by a predetermined protocol.

6, the storage unit 441 of the d-axis current control unit 440 of the servo drive 400 of the resonance suppression control system 1 of the machine tool according to an embodiment of the present invention is a basic data storage unit 4411 , a feedback data storage unit 4412 , and a real-time data storage unit 4413 .

The basic data storage unit 4411 relates to the motor pole constant, the magnetic flux of the permanent magnet, the resistance of the motor stator winding, the inductance of the motor stator winding, the rotor angular velocity, the rotor position error between the main motor unit and the auxiliary motor unit, and the low-pass filter Save the information. The basic data storage may be performed by the operator through the numerical control unit 100 or the main operation unit 200, and may be stored in the PLC 300 in the form of a program.

The feedback data storage unit 4412 stores feedback information about positions, speeds, d-axis currents, and q-axis currents of the main and auxiliary motors generated during parallel operation of the main and auxiliary motors.

The real-time data storage unit 4413 stores the results of the measurement unit, the selection unit, and the calculation unit in real time. The real-time data storage unit 4413 is electrically connected to the measurement unit, the selection unit, and the calculation unit, the power conversion unit, the feedback data storage unit, the servo motor unit, the numerical control unit, the main operation unit, and the PLC and communicates by a predetermined protocol. can be performed.

6, the calculation unit 442 of the d-axis current control unit 440 of the servo drive 400 of the resonance suppression control system 1 of the machine tool according to an embodiment of the present invention calculates the DC offset component It includes a unit 4421 , a pulsation component calculation unit 4422 , and a d-axis feedback current calculation unit 4423 .

The DC offset component calculation unit 4421 calculates the d-axis DC offset component of the auxiliary motor unit based on the d-axis current value of the auxiliary motor unit converted by the coordinate conversion unit, the selection result of the selection unit, and information stored in the storage unit.

The pulsation component calculation unit 4422 is the d-axis pulsation of the auxiliary motor unit by the d-axis current value of the auxiliary motor unit converted by the coordinate conversion unit, the selection result of the selection unit, information stored in the storage unit, and the calculated value of the DC offset component calculation unit Calculate the ingredients.

The d-axis feedback current calculation unit 4423 calculates the selection result of the selection unit, the d-axis current value of the main motor unit converted by the coordinate conversion unit, information stored in the storage unit, the calculated value of the DC offset component calculation unit, and the calculation of the pulsation component calculation unit Calculate the d-axis feedback current of the main motor part by the value.

Therefore, the resonance suppression control system of the machine tool according to the present invention converts the current measured by the measurement unit in real time to the main motor unit and the servo motor unit, which vary in real time according to the operating state of the servo motor unit according to the tandem control of the servo drive, to the d-q axis current. After conversion to , the main motor unit and the servo motor unit are selected by comparing each other, and according to the result of the calculation unit of the d-axis current control unit, the corrected d-axis feedback current is transmitted to the main motor unit in real time, and the corrected d-axis feedback current of the main motor unit is As the d-axis current of the main motor is controlled in the state that is fed back to the main motor, resonance suppression is automatically performed in real time through tandem control of the main and auxiliary motors, so all speeds of the two servomotors, the main and auxiliary motors, are Resonance suppression regardless of the type of servo motor unit through precise tandem control synchronized from Maximizes the precision and reliability of the servo control device of the tool changer or automatic pallet changer, increases the stability and processing efficiency of the machine tool, promotes operator convenience, and minimizes the non-working time to increase the productivity of the machine tool. can be maximized.

A tandem control principle of the servo drive will be described with reference to FIGS. 3 to 6 and 8 to 9 .

When controlling the torque of the main motor, only the q-axis current is affected. That is, as shown in Equation 1, during torque control of the main motor, the d-axis current is not affected and only the q-axis current is affected.

[Equation 1]

In addition, the torque control of the auxiliary motor is affected by both the d-axis current and the q-axis current of the main motor. That is, as shown in Equation 2, during torque control of the auxiliary motor unit, it is affected by both the d-axis current and the q-axis current of the main motor.

[Equation 2]

In the resonance suppression control system and control method of a machine tool according to the present invention, the pulsation component of the state in which the DC offset component is removed from the d-axis current of the auxiliary motor unit is reflected in the d-axis current (i _d ^f ) fed back to the main motor unit. control, and since the pulsation component of the auxiliary motor is independent of the torque control of the main motor, only the resonance suppression control through the tandem control can be performed without affecting the torque of the main motor.

As described above, the current of the main motor unit and the auxiliary motor unit is measured through the measuring unit. That is, the currents of the main motor unit and the auxiliary motor unit measured through the measurement unit become current values in the abc coordinates.

Thereafter, the current values of the main motor unit and the auxiliary motor unit in the abc coordinates are converted into d-q coordinates through the coordinate conversion unit. Thereafter, the d-axis current value is transmitted to the selection unit and the d-axis current control unit.

The selection unit compares the d-axis current values of the main motor unit and the auxiliary motor unit, which change in real time according to the operating state of the servo motor unit, in real time and selects them in real time.

That is, the selection unit compares and analyzes the d-axis current values by Equation 3, and when the result value (K) of Equation 3 is greater than or equal to 0, M2 is selected as the main motor unit and M1 is selected as the auxiliary motor unit. (K ≥0)

Conversely, if the result of Equation 3 is less than 0, M1 is selected as the main motor unit and M2 is selected as the auxiliary motor unit. (K < 0)

[Equation 3]

K =

Thereafter, the DC offset component calculation unit calculates the d-axis DC offset component of the auxiliary motor unit by the d-axis current value of the auxiliary motor unit converted by the coordinate conversion unit, the selection result of the main motor unit and the auxiliary motor unit of the selection unit, and the information stored in the storage unit. Calculate. That is, the DC offset component calculating unit extracts the d-axis DC offset component of the auxiliary motor unit through filtering the d-axis current value of the auxiliary motor unit converted by the coordinate conversion unit with a low pass filter and calculates it by Equation 4 .

[Equation 4]

Then, the d-axis current value of the auxiliary motor unit converted by the coordinate conversion unit in the pulsation component calculation unit, the selection result of the main motor unit and the auxiliary motor unit of the selection unit, information stored in the storage unit, and the calculated value of the DC offset component calculation unit Calculate the d-axis pulsation component of the motor. That is, the pulsation component calculating unit calculates the d-axis pulsation component of the auxiliary motor unit by subtracting the d-axis DC offset component from the d-axis current of the auxiliary motor unit by Equation 5.

[Equation 5]

i ^ac _{d_mn} = i _{d_mn} ^-

After that, in the d-axis feedback current calculation unit, the selection result of the main motor unit and the auxiliary motor unit of the selection unit, the d-axis current value of the main motor unit converted by the coordinate conversion unit, information stored in the storage unit, the calculated value of the DC offset component calculation unit, and pulsation The d-axis feedback current of the main motor unit is calculated by the calculated value of the component calculation unit. That is, the d-axis feedback current calculation unit reflects and derives only the pulsation component from the d-axis current of the auxiliary motor unit by Equation (5).

[Equation 6]

i _d ^f = i _{d_m2} ⁺ i ^ac _{d_mn}

Specifically, when M2 is selected as the main motor unit in the selection unit and M1 is selected as the auxiliary motor unit, the d-axis feedback current (i _d ^f) of the main motor unit is derived from Equation 7, and on the contrary, M1 is selected as the main motor unit in the selection unit and when M2 is selected as the auxiliary motor unit, the d-axis feedback current (i _d ^f) of the main motor unit is derived from Equation 8.

[Equation 7]

[Equation 8]

Each factor in Equations 1 to 8 described above is as follows.

P _f : motor extreme constant

φ _f : magnetic flux of permanent magnet

R _s : resistance of the motor stator winding

L _s : inductance of the stator windings of the motor

ω _r : angular velocity of the rotor

ω _c : cutoff frequency of the low-pass filter

Δθ : Rotor position error between the main motor unit and the auxiliary motor unit

i _{d_m2} : d-axis current of main motor part

i _{d_m1} : d-axis current of auxiliary motor

: d축 전류 직류오프셋 성분

: d-axis current DC offset component

i ^ac _{d_mn} : d-axis current pulsation component

(

는 실수,

는 허수 즉 s는 주파수 공간에서의 크기와 위상을 나타내는 인자이다.)S:

(

is a mistake,

is an imaginary number, that is, s is a factor representing magnitude and phase in frequency space.)

In this way, the resonance suppression control system of the machine tool according to the present invention automatically generates the resonance generated when two servo motors are operated in parallel by one power unit and a power conversion unit in real time regardless of the type and capacity of the servo motor. By performing tandem control in the current loop rather than the speed loop, operator convenience is promoted and the productivity of the machine tool can be maximized by minimizing the non-working time.

In addition, although not shown in the drawings, the resonance suppression control system 1 of the machine tool according to an embodiment of the present invention may further include an input unit and a display unit.

The input unit is installed in the form of a switch or a touch button on the operation panel or the main operation unit, etc., and performs a function that the operator can arbitrarily select so as to perform or not perform the resonance suppression control in real time during parallel operation of the servo motor unit.

That is, if the function of the d-axis current control unit is not selected during parallel operation of the main motor unit and the auxiliary motor unit of the servo motor unit of the resonance suppression control system of the machine tool at the input unit, the resonance suppression control function of the machine tool does not work.

The display unit displays the measurement unit, coordinate conversion unit, selection unit, feedback data, real-time data, DC offset component calculation value, pulsation component calculation value, and d-axis feedback current calculation value on a monitor, etc. In parallel operation of two servomotors, the presence or absence of resonance suppression and control status can be checked. Although not necessarily limited thereto, the display unit may be composed of an LCD, LED, PDP monitor, etc. in the main operation unit or the numerical control unit.

As shown in Figure 7, the resonance suppression control method of the machine tool according to an embodiment of the present invention is a basic data storage step (S1), PLC execution step (S2), servo drive execution step (S3), the current of the power conversion unit Application step (S4), feedback information storage step (S5), current measurement step (S6), coordinate conversion step (S7), selection step (S8), d-axis DC offset component calculation step (S9), d-axis pulsation component calculation It includes a step S10, a d-axis feedback current calculation step S11, a processing step S12, and a real-time data storage step S13. In each step, the performance or content of the system or device in detail is the same as the tandem control system of the machine tool of the specification of the present invention. We focus on the singularities.

Basic data information for tandem control of the servo motor unit including the main motor unit and the auxiliary motor unit connected in parallel to each other with the servo drive is stored in the basic data storage unit 4411 . Specifically, the operator numerically controls the motor pole constant, the magnetic flux of the permanent magnet, the resistance of the motor stator winding, the inductance of the motor stator winding, the rotor angular velocity, the rotor position error between the main and auxiliary motor units, and the low-pass filter. (100) or it can be performed through the main operation unit 200, and stored in the PLC 300 in the form of a program.

After the basic data storage step (S1), a control command is executed in the PLC through communication with the numerical control unit or the main operation unit.

After the PLC execution step (S2), the servo drive executes the control command transmitted from the PLC.

After the servo drive performing step (S3), the power conversion unit applies a current to the servo motor unit according to the signal of the servo drive.

After the current application step (S4) of the power conversion unit, feedback information about the position, speed, d-axis current, and q-axis current of the main motor unit and the auxiliary motor unit generated during parallel operation of the main motor unit and the auxiliary motor unit is stored in the feedback data storage unit Save to (4412).

After the feedback information storage step (S5), the current of the main motor unit and the auxiliary motor unit is measured by the measuring unit.

After the current measurement step (S6), the measured abc coordinate current value is converted into d-q coordinates by the coordinate conversion unit.

After the coordinate conversion step (S7), the converted d-axis current value is compared with each other and the main motor unit and the auxiliary motor unit which are changed in real time are automatically selected and selected through Equation (3).

After the selection step (S8), the d-axis DC offset component of the auxiliary motor unit selected as the auxiliary motor unit is extracted by the DC offset component calculation unit through Equation (4).

After the d-axis DC offset component calculation step (S9), the d-axis pulsation component of the auxiliary motor unit is derived from the pulsation component calculation unit through Equation 5 by the DC offset component calculated value.

After the d-axis pulsation component calculation step (S10), the d-axis feedback current of the main motor unit is calculated by the converted d-axis current value of the main motor unit, the DC offset component calculated value of the auxiliary motor unit, and the pulsation component calculated value of the auxiliary motor unit do. That is, the d-axis feedback current calculation unit calculates the d-axis feedback current fed back to the main motor unit in a state in which the pulsation component of the auxiliary motor unit is reflected through Equation (6). If, according to the selection result of the selection part, the main motor part is selected as M2 and the auxiliary motor part is selected as M1, the d-axis feedback current of the main motor part is derived by Equation 7, and the main motor part is selected as M1 according to the selection result. is selected, and when the auxiliary motor unit is selected as M2, the d-axis feedback current of the main motor unit is derived by Equation (8).

After the d-axis feedback current calculation step (S11), the d-axis current control of the main motor unit is performed through the processing unit with the calculated d-axis feedback current.

As such, in the resonance suppression control method of the machine tool according to the present invention, the main motor part and the auxiliary motor part are changed in real time according to the operating state of the servo motor part, and the current of the main motor part and the auxiliary motor part which is changed in real time is measured by the measuring part, After this is converted into d-q coordinates in the coordinate conversion unit, the main motor unit and the auxiliary motor unit are selected in the selection unit in real time, and the d-axis feedback current fed back to the main motor unit by reflecting the pulsation component of the auxiliary motor unit calculated in real time from the auxiliary motor unit is changed in real time to automatically suppress resonance according to the operation of the servo motor unit.

After the processing step (S12), the selection result of the selection of the main motor unit and the auxiliary motor unit, the calculated value of the DC offset component of the auxiliary motor unit, the calculated value of the pulsation component of the auxiliary motor unit, and the d-axis feedback current value of the main motor unit are real-time data save to storage

Therefore, the resonance suppression control method of the machine tool according to the present invention reflects the pulsation component of the auxiliary motor unit calculated in real time from the auxiliary motor unit and changes the d-axis feedback current fed back to the main motor unit in real time, thereby changing the main motor unit and the servo motor unit. As it is automatically and quickly and accurately performed through resonance suppression through tandem control according to operation, it is set and operated stably regardless of the type, capacity or system parameters of the servomotor to promote operator convenience and finally automatic tool replacement By controlling a device driven by a servo motor, such as a device or an automatic pallet changer, manufacturing cost is reduced, reliability is improved by noise reduction, and can be used universally regardless of the type and capacity of the servo motor. It is possible to increase the compatibility of the resonance suppression control system and its control method.

In addition, the resonance suppression control method of the machine tool according to the present invention is a pulsation component of the auxiliary motor unit that is calculated in real time from the auxiliary motor unit resonance generated when two servo motors are operated in parallel by one power unit and a power conversion unit By changing the d-axis feedback current fed back to the main motor unit in real time by reflecting and the tandem control system of machine tools can be miniaturized and the space utilization can be maximized.

8 is a view showing that the tandem control does not occur smoothly during tandem control at 450 rpm in a state where the resonance suppression control system and the control method of the machine tool according to the present invention are not applied, the pulsation increases, the system responsiveness decreases, and the vibration This indicates a state that occurs repeatedly. Specifically, in FIG. 9 , the amount of change in the U-phase current of the main motor unit M2 over time is indicated by a solid line at the upper portion of the graph, and the U-phase current of the auxiliary motor unit M1 is indicated by a dotted line at the upper portion of the graph. . The U-phase current of the main motor unit (M2) and the U-phase current of the auxiliary motor unit (M1) do not almost match over time, and the d-axis feedback current reflecting the pulsation component of the auxiliary motor unit is not transmitted to the main motor unit. Accordingly, the d-axis current of the main motor unit (M2) is stably changed over time and no vibration is generated, but the d-axis current of the auxiliary motor unit (M1) continues to change severely over time, causing vibration and The pulsation causes the responsiveness, accuracy and reliability of tandem control to deteriorate, and the quality of processing decreases.

On the other hand, FIG. 9 shows a graph of a state in which the resonance suppression control system and the control method of the machine tool according to the present invention are applied to perform tandem control. 9 shows the d-axis pulsation component of the auxiliary motor unit M1 in the d-axis feedback current fed back to the main motor unit M2 at 450 rpm in the same manner as in FIG. 8 to control the d-axis current of the main motor unit M1. With the lapse of time, the U-phase current of the main motor unit M2 and the U-phase current of the auxiliary motor unit M1 almost coincide with the lapse of time, and the d-axis current of the auxiliary motor unit also changes with the lapse of time, unlike FIG. It can be seen that the resonance suppression is controlled by maintaining almost constant. Similarly, in FIG. 10 , the amount of change in the U-phase current of the main motor unit M2 is indicated by a solid line on the upper portion of the graph, the U-phase current of the auxiliary motor unit M1 is indicated by a dotted line on the upper portion of the graph, and the main motor portion (M2) The d-axis current is indicated by a two-dot chain line, and the d-axis current of the auxiliary motor unit M1 is indicated by a one-dot chain line.

As described above, the resonance suppression control system of the machine tool and the control method thereof according to the present invention reflect the pulsation component of the auxiliary motor unit calculated in real time from the auxiliary motor unit and change the d-axis feedback current fed back to the main motor unit in real time to change the main motor unit As it is automatically and quickly and accurately performed through resonance suppression through tandem control according to the operation of the servomotor and servomotor unit, stable setting and operation regardless of the type, capacity, or system parameters of the servomotor for the convenience of the operator and finally By controlling devices driven by servo motors such as automatic tool changers or automatic pallet changers, manufacturing costs are reduced, reliability is improved by reducing noise, and can be used universally regardless of the type and capacity of the servo motor. Therefore, it is possible to increase the compatibility of the resonance suppression control system of the machine tool and its control method, reduce the size of the machine tool and the tandem control system of the machine tool by removing unnecessary components, and maximize the space utilization.

In addition, the resonance suppression control system of the machine tool and the control method thereof according to the present invention are the main motor unit and the servo motor unit that change in real time according to the operating state of the servo motor unit according to the tandem control of the servo drive. is converted into d-q-axis current, compared with each other to select the main motor unit and the servo motor unit, and according to the result of the calculation unit of the d-axis current control unit, the corrected d-axis feedback current is transmitted to the main motor unit in real time, and the corrected main motor unit d As the d-axis current of the main motor is controlled while the axis feedback current is fed back to the main motor, resonance suppression is automatically performed in real time through tandem control of the main and auxiliary motors. Resonance suppression regardless of the type of servo motor through precise tandem control synchronized at all speeds and positions of the motor unit. Maximizes the precision and reliability of the servo control of the automatic tool changer or automatic pallet changer, increases the stability and processing efficiency of the machine tool, promotes operator convenience, and minimizes non-working time. Maximize machine productivity.

Although the detailed description of the present invention described above has been described with reference to preferred embodiments of the present invention, those skilled in the art or those having ordinary knowledge in the art will It will be understood that various modifications and variations of the present invention can be made without departing from the spirit and scope of the present invention. Accordingly, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

1: resonance suppression control device 10: first servo drive
11: second servo drive 20: first inverter
21: second inverter 30: first servo motor
31: second servo motor 100: numerical control unit
200: main operation unit 300: PLC
400: servo drive 410: measurement unit
420: coordinate transformation unit 430: selection unit
440: d-axis current control unit 441: storage unit
4411: basic data storage unit 4412: feedback data storage unit
4413: real-time data storage unit 442: calculation unit
4421: DC offset component calculation unit 4422: pulsation component calculation unit
4423: d-axis feedback current calculation unit 443: processing unit
500: power conversion unit 600: main motor unit
M1: Auxiliary motor part M2: Main motor part

Claims (10)

numerical control unit;
main work unit;
PLC for executing a control command through communication with the numerical control unit or the main operation unit;
a servo drive that executes a control command of the PLC;
a servo motor unit having a main motor unit and an auxiliary motor unit connected in parallel to each other, and driven through tandem control of the servo drive; and
A power conversion unit electrically connected to the servo motor unit and the servo drive to apply a current to the servo motor unit; includes,
The main motor unit and the auxiliary motor unit of the servo motor unit are changed in real time according to the operating state of the servo motor unit according to the tandem control of the servo drive,
The servo drive reflects the pulsation component of the auxiliary motor unit calculated in real time from the auxiliary motor unit and changes the d-axis feedback current fed back to the main motor unit in real time to automatically suppress resonance according to the operation of the servo motor unit Resonance suppression control system of a machine tool, characterized in that.
According to claim 1,
The servo drive is
a measuring unit for measuring the current of the main motor unit and the auxiliary motor unit in real time;
a coordinate conversion unit converting the current value measured by the measuring unit into dq coordinates;
a selection unit selecting the main motor unit and the auxiliary motor unit which are changed in real time by comparing the d-axis current values converted through the coordinate conversion unit; and
d-axis current for tandem control of the main motor unit and the auxiliary motor unit by correcting in real time the d-axis feedback current fed back to the main motor unit in which the pulsation component of the auxiliary motor unit that changes in real time according to the selection result of the selection unit is reflected Control system; resonance suppression control system of the machine tool, characterized in that it comprises.
3. The method of claim 2,
The d-axis current control unit,
a storage unit for storing information for tandem control for suppressing resonance occurring during parallel operation of the main motor unit and the auxiliary motor unit; and
and a calculation unit for calculating a d-axis feedback current fed back to the main motor unit based on the selection result of the selection unit and the information stored in the storage unit.
4. The method of claim 3,
The d-axis current control unit,
The d-axis feedback current corrected in real time is transmitted to the main motor unit according to the results of the selection unit and the calculation unit, and the main motor unit d in a state in which the corrected d-axis feedback current of the main motor unit is fed back to the main motor unit Resonance suppression control system of a machine tool comprising a; a processing unit that performs resonance suppression in real time through tandem control of the main motor unit and the auxiliary motor unit as the shaft current is controlled.
5. The method of claim 4,
The storage unit,
Basic data storage unit that stores information about motor pole constant, permanent magnet magnetic flux, motor stator winding resistance, motor stator winding inductance, rotor angular velocity, rotor position error between the main and auxiliary motor units, and low-pass filter ;
a feedback data storage unit for storing feedback information on positions, speeds, d-axis currents, and q-axis currents of the main motor unit and the auxiliary motor unit generated during parallel operation of the main motor unit and the auxiliary motor unit; and
and a real-time data storage unit configured to store the results of the measurement unit, the selection unit, and the calculation unit in real time. 6. The method of claim 5,
The calculation unit,
a DC offset component calculation unit for calculating a d-axis DC offset component of the auxiliary motor unit based on the d-axis current value of the auxiliary motor unit converted by the coordinate conversion unit, the selection result of the selection unit, and information stored in the storage unit;
The d-axis pulsation component of the auxiliary motor unit by the d-axis current value of the auxiliary motor unit converted by the coordinate conversion unit, the selection result of the selection unit, information stored in the storage unit, and the calculated value of the DC offset component calculation unit a pulsation component calculation unit to calculate; and
Based on the selection result of the selection unit, the d-axis current value of the main motor unit converted by the coordinate conversion unit, the information stored in the storage unit, the calculated value of the DC offset component calculation unit, and the calculated value of the pulsation component calculation unit, the Resonance suppression control system of a machine tool comprising a; d-axis feedback current calculation unit for calculating the d-axis feedback current of the main motor unit.
7. The method of claim 6,
The DC offset component calculation unit,
Resonance suppression control system of a machine tool, characterized in that by filtering the d-axis current value of the auxiliary motor unit converted by the coordinate conversion unit with a low-pass filter to extract and calculate the d-axis DC offset component of the auxiliary motor unit.
8. The method of claim 7,
The d-axis current control unit,
Resonance by tandem control of the main motor unit and the auxiliary motor unit through the pulsation reduction of the auxiliary motor unit by controlling the d-axis feedback current of the main motor unit fed back to the main motor unit in real time to 0 through the d-axis feedback current calculation unit A machine tool resonance suppression control system, characterized in that it performs suppression.
storing basic data information for tandem control of a servo motor unit having a main motor unit and an auxiliary motor unit connected in parallel to each other with a servo drive;
performing a control command in the PLC through communication with a numerical control unit or a main operation unit;
executing the control command transmitted from the PLC in the servo drive;
applying a current to the servo motor unit by the power conversion unit according to the signal of the servo drive;
Storing feedback information about the position, speed, d-axis current, and q-axis current of the main motor unit and the auxiliary motor unit generated during parallel operation of the main motor unit and the auxiliary motor unit;
measuring the current of the main motor unit and the auxiliary motor unit;
converting the measured current value into dq coordinates;
comparing the converted d-axis current values with each other and selecting the main motor unit and the auxiliary motor unit which are changed in real time;
calculating a d-axis DC offset component of the auxiliary motor unit;
calculating a d-axis pulsation component of the auxiliary motor unit based on the DC offset component calculation value;
calculating a d-axis feedback current of the main motor unit based on the converted d-axis current value of the main motor unit, the DC offset component calculated value, and the pulsation component calculated value; and
Including; performing d-axis current control of the main motor unit with the calculated d-axis feedback current;
The main motor unit and the auxiliary motor unit are changed in real time according to the operating state of the servo motor unit, and the d-axis feedback current fed back to the main motor unit by reflecting the pulsation component of the auxiliary motor unit calculated in real time from the auxiliary motor unit. Resonance suppression control method of a machine tool, characterized in that by changing in real time to automatically perform the resonance suppression according to the operation of the servo motor unit.
10. The method of claim 9,
After performing the d-axis current control of the main motor unit, the selection result of the main motor unit and the auxiliary motor unit, the DC offset component calculation value, the pulsation component calculation value, and the d-axis feedback current value are stored in real time Resonance suppression control method of a machine tool comprising the;

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