阅读说明：本技术 机床的共振抑制控制装置以及共振抑制控制方法 (Resonance suppression control device and resonance suppression control method for machine tool ) 是由 尹喆 于 2019-08-28 设计创作，主要内容包括：根据本发明的机床的共振抑制控制装置,其特征为,包括：数控部；主操作部；PLC,通过与所述数控部或者所述主操作部的通信,执行控制指令；伺服驱动器,执行所述PLC的控制指令；伺服电机部,随着所述伺服驱动器的控制而驱动；以及电力转换部,与所述伺服电机部以及所述伺服驱动器电连接,而向所述伺服电机部施加电能,所述电力转换部根据所述伺服驱动器的信号,调整向所述伺服电机部施加的电能,从而控制因所述伺服电机部的运转而引起的共振抑制。(According to the present invention, there is provided a resonance suppression control device for a machine tool, comprising: a numerical control unit; a main operation section; a PLC for executing a control command through communication with the numerical control unit or the main operation unit; the servo driver executes the control instruction of the PLC; a servo motor part driven by the control of the servo driver; and a power conversion unit electrically connected to the servo motor unit and the servo driver and applying electric energy to the servo motor unit, wherein the power conversion unit adjusts the electric energy applied to the servo motor unit according to a signal of the servo driver, thereby controlling resonance suppression caused by operation of the servo motor unit.)

1. A resonance suppression control device for a machine tool, comprising:

a numerical control unit;

a main operation section;

a PLC for executing a control command through communication with the numerical control unit or the main operation unit;

the servo driver executes the control instruction of the PLC;

a servo motor part driven by the control of the servo driver; and

a power conversion unit electrically connected to the servo motor unit and the servo driver and applying electric power to the servo motor unit,

the power conversion unit adjusts the electric energy applied to the servo motor unit based on the signal of the servo driver, thereby controlling the suppression of resonance caused by the operation of the servo motor unit.

2. The resonance suppression control device for a machine tool according to claim 1,

the servo motor part comprises a first servo motor and a second servo motor which are connected in parallel,

the resonance generated when the first servo motor and the second servo motor are operated in parallel is controlled by adjusting the electric energy applied to the first servo motor and the second servo motor by the power conversion unit.

3. The resonance suppression control apparatus for a machine tool according to claim 2,

the servo driver includes:

a first servo motor feedback information storage unit that stores position and speed feedback information of the first servo motor generated when the first servo motor and the second servo motor are operated in parallel;

a speed command unit for outputting an operation speed signal of the servo motor unit based on the position command transmitted from the numerical control unit and the feedback signal transmitted from the first servo motor feedback information storage unit;

an effective torque command unit that outputs an effective torque signal to be transmitted to the power conversion unit to drive the servo motor unit, based on the speed command transmitted from the speed command unit and the feedback signal transmitted from the first servo motor feedback information storage unit; and

and a resonance suppression control unit that outputs the reactive torque signal transmitted to the power conversion unit.

4. The resonance suppression control device for a machine tool according to claim 3,

the resonance suppression control unit includes:

a basic data storage part for storing information related to a high frequency gain limit value, a maximum value of a flux linkage of a corresponding permanent magnet, a natural frequency of the servo motor part, an angular velocity at an operating point, a direct current gain of the resonance suppression controller, an inductance of a winding of a stator of the servo motor part, a pole constant of the servo motor part, a stator winding resistance of the servo motor part, and a rotor inertia moment of the servo motor part;

a second servo motor feedback information storage unit that stores position and speed feedback information of the second servo motor generated when the second servo motor and the first servo motor are operated in parallel;

a calculation unit that calculates an ineffective torque value to be transmitted to the power conversion unit, based on the data stored in the basic data storage unit and the feedback information of the first servomotor and the second servomotor stored in the second servomotor feedback information storage unit and the first servomotor feedback information storage unit; and

and a reactive torque command unit that outputs a reactive torque signal to transmit the calculated reactive torque value to the power conversion unit when the reactive torque value calculated by the calculation unit is not 0.

5. The resonance suppression control device for a machine tool according to claim 4, wherein the power conversion unit suppresses resonance generated when the first servomotor and the second servomotor are operated in parallel by adjusting the intensities of the current and the voltage applied to the first servomotor and the second servomotor, respectively, based on the signals transmitted to the effective torque command unit and the ineffective torque command unit.

6. A resonance suppression control method for a machine tool, comprising:

storing information on a high-frequency gain limit value, a maximum value of a flux linkage of the corresponding permanent magnet, a natural frequency of the servo motor, an angular velocity at an operating point, a direct-current gain of the resonance suppression controller, an inductance of a winding of a stator of the servo motor, a pole constant of the servo motor, a stator winding resistance of the servo motor, and a rotor inertia moment of the servo motor in a basic data storage unit;

a step of executing a control command at the PLC through communication with the numerical control part or the main operation part;

a step of executing a control command transmitted from the PLC at a servo driver;

a step in which a power conversion unit applies electric power to a servo motor unit including a first servo motor and a second servo motor, based on a signal from the servo driver;

a step of storing, in a first servo motor feedback information storage unit, position and speed feedback information of the first servo motor generated when the first servo motor and the second servo motor are operated in parallel;

a step of storing, in a second servo motor feedback information storage unit, position and speed feedback information of the second servo motor generated when the second servo motor and the first servo motor are operated in parallel; and

a step of calculating, at a calculation unit, an ineffective torque value transmitted to the power conversion unit based on the data stored in the basic data storage unit and the feedback information of the first servomotor and the second servomotor stored in the second servomotor feedback information storage unit and the first servomotor feedback information storage unit,

the power conversion unit adjusts the electric energy applied to the first servomotor and the second servomotor of the servomotor unit, respectively, based on the calculated value of the calculation unit, thereby controlling resonance suppression caused by the operation of the servomotor unit.

7. The resonance suppression control method of a machine tool according to claim 6,

after the step of operating, further comprising: and comparing whether or not the reactive torque value calculated by the calculation unit is 0.

8. The resonance suppression control method of a machine tool according to claim 7,

after the step of comparing, further comprising: and a step of outputting a reactive torque signal to transmit the calculated reactive torque value to the power conversion unit when the reactive torque value is not 0.

Technical Field

The present invention relates to a resonance suppression control device and a resonance suppression control method for a machine tool, and more particularly, to a resonance suppression control device and a resonance suppression control method for a machine tool, in which a resonance suppression control unit transmits an ineffective torque command to a power conversion unit, thereby adjusting electric energy applied to a first servomotor and a second servomotor in the power conversion unit, and suppressing resonance generated when two servomotors are operated in parallel by one power conversion unit and one servo driver, thereby improving stability and reliability of the machine tool, saving manufacturing costs and maintenance costs, and achieving miniaturization.

Background

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

Various machine tools such as a turning center, a vertical/horizontal machining center, a gantry machining center, a swiss turning machine, an electric discharge machine, a horizontal NC boring machine, a CNC lathe, and the like are widely used in various industrial fields to meet the use of corresponding operations.

In general, many machine tools currently in use have a control panel to which Numerical Control (NC) or CNC (computerized numerical control) technology is applied. The operating panel has a plurality of function switches or buttons and a display.

In addition, the machine tool is provided with a table on which a material as a workpiece is placed and which conveys the workpiece for machining; a chuck to prepare a workpiece before machining; a spindle to which a tool or a workpiece is coupled to rotate; a tailstock for supporting when processing a workpiece or the like; shock mounts, and the like.

Generally, a machine tool includes a transport unit that transports a table, a tool table, a spindle, a tailstock, a vibration damping device, and the like along a transport shaft to perform various kinds of machining.

In general, a machine tool uses a plurality of tools for performing a plurality of types of machining, and a tool magazine or a turret is used as a tool storage location for storing and storing the plurality of tools.

In general, a machine Tool includes an Automatic Tool Changer (ATC) for drawing out a specific Tool from a Tool magazine or storing it again by a command from a numerical control unit in order to improve productivity of the machine Tool.

In general, a machine tool is provided with an Automatic Pallet Changer (APC) to minimize a non-machining time. An automatic pallet exchange device (APC) automatically exchanges pallets between a workpiece processing area and a workpiece setting area. A workpiece may be carried on the pallet.

In general, a machine tool uses a servo motor to drive an Automatic Tool Changer (ATC), an Automatic Pallet Changer (APC), a tailstock, a vibration damping device, or the like.

As described above, a device that ultimately controls an Automatic Tool Changer (ATC) or an Automatic Pallet Changer (APC), a tailstock, or a vibration damping device by controlling a SERVO MOTOR (SERVO MOTOR) is referred to as a SERVO control device.

In particular, when a large Automatic Pallet Changer (APC) is bulky or requires a large force, two servo motors are operated in parallel to drive one shaft, which is called dual drive control (Tandem control) for reasons of productivity and economy and for technical reasons that sufficient torque cannot be obtained by only one servo motor.

However, when two servo motors are used in the related art, as shown in fig. 1, one inverter and one servo driver are combined with each servo motor in the related art servo control device. That is, the operation is performed by a Multi-inverter Multi-servo motor (Multi inverter Multi-servo motor) in which the first inverter 20 and the first servo driver 10 are connected to the first servo motor 30, and the second inverter 21 and the second servo driver 11 are connected to the second servo motor 31.

However, the multi-inverter multi-servo motor requires a separate inverter and servo driver for each servo motor, which increases the size of the device, increases the manufacturing cost and maintenance cost, and makes it impossible to reduce the size of the machine tool.

In order to solve the above problem, as shown in fig. 2, a Single inverter multi-servo motor (Single inverter multi-servo motor) in which one inverter 20 and one servo driver 10 are operated in parallel with each other in two servo motors 30 and 31 has been proposed.

However, unlike an asynchronous motor having a slip, since the servo motors are permanent magnet type synchronous motors and have no slip, the servo motors can be stably operated in parallel only by synchronizing the two servo motors without speed deviation, otherwise the stability and reliability of the servo control device are lowered by resonance and step-out, and finally there is a problem that the stability and reliability of the machine tool and the machining precision are lowered.

In order to solve the above-described resonance suppression control problem, three types of conventional resonance suppression control apparatuses and resonance suppression control methods have been proposed.

The first is an attenuation control apparatus and method using an auxiliary inverter and an auxiliary winding, which has a structure in which a main inverter and an auxiliary inverter are separately provided to form a servo motor and an auxiliary winding, and has problems in that manufacturing costs are increased and mass production is difficult due to the provision of two conventional inverters.

The second type is an active damping control (active damping control) device and method, which cannot flexibly deal with actual resonance generation or a large amount of disturbance or variation by setting resonance suppression control only by an empirical method, and has a problem that reliability and stability of a servo control device cannot be always ensured, and only manufacturing cost increases.

The third type is a vibration reduction apparatus and method using a load vibration analyzer (load vibration analyzer), which calculates resonance suppression control by an empirical method, requires a sensor or the like capable of sensing a vibration phenomenon of a magnetic axis current, increases manufacturing costs, performs resonance suppression control without considering actual resonance generation or a real-time variation amount due to an apparatus operation state, significantly deteriorates accuracy and reliability, and finally has a problem in that machining precision and reliability of a machine tool are deteriorated.

Disclosure of Invention

Technical subject

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a resonance suppression control device and a resonance suppression control method for a machine tool, in which a resonance suppression control unit transmits an ineffective torque command to a power conversion unit, electric energy applied to a first servomotor and a second servomotor is adjusted in the power conversion unit, and resonance generated when the two servomotors are operated in parallel is suppressed by one power conversion unit and one servo driver, thereby achieving stable operation and operator convenience, and finally, by controlling a device driven by a servomotor, such as an automatic tool changer or an automatic pallet changer, manufacturing cost can be saved, reliability improvement due to noise reduction, and miniaturization of the device.

Another object of the present invention is to provide a resonance suppression control apparatus and a resonance suppression control method for a machine tool, which can perform precise control of synchronization at all speeds and positions of two servo motors by adjusting electric energy applied to a first servo motor and a second servo motor in a power conversion unit using a reactive torque command transmitted to the power conversion unit by a resonance suppression control unit, thereby greatly improving the accuracy and reliability of servo control of an automatic tool changer or an automatic pallet changer.

Means for solving the problems

In order to achieve the object of the present invention, a resonance suppression control device for a machine tool according to the present invention includes: a numerical control unit; a main operation section; a PLC for executing a control command through communication with the numerical control unit or the main operation unit; the servo driver executes the control instruction of the PLC; a servo motor part driven by the control of the servo driver; and a power conversion unit electrically connected to the servo motor unit and the servo driver to apply power to the servo motor unit, wherein the power conversion unit adjusts the power applied to the servo motor unit in accordance with a signal from the servo driver to suppress resonance caused by controlling the operation of the servo motor unit.

In addition, in a preferred another embodiment of the resonance suppression control apparatus for a machine tool according to the present invention, the servo motor section of the resonance suppression control apparatus for a machine tool includes a first servo motor and a second servo motor connected in parallel with each other, and the electric power applied to each of the first servo motor and the second servo motor is adjusted by the power conversion section, thereby controlling resonance generated when the first servo motor and the second servo motor are operated in parallel.

In addition, in a preferred other embodiment of the resonance suppression control apparatus for a machine tool according to the present invention, the servo driver of the resonance suppression control apparatus for a machine tool may include: a first servo motor feedback information storage unit that stores position and speed feedback information of the first servo motor generated when the first servo motor and the second servo motor are operated in parallel; a speed command unit for outputting an operation speed signal of the servo motor unit based on the position command transmitted from the numerical control unit and the feedback signal transmitted from the first servo motor feedback information storage unit; an effective torque command unit that outputs an effective torque signal to be transmitted to the power conversion unit to drive the servo motor unit, based on the speed command transmitted from the speed command unit and the feedback signal transmitted from the first servo motor feedback information storage unit; and a resonance suppression control unit that outputs an ineffective torque signal transmitted to the power conversion unit.

In addition, in a preferred other embodiment of the resonance suppression control apparatus for a machine tool according to the present invention, the resonance suppression control section of the servo driver of the resonance suppression control apparatus for a machine tool may include: a basic data storage part for storing information related to a high frequency gain limit value, a maximum value of a flux linkage of a corresponding permanent magnet, a natural frequency of the servo motor part, an angular velocity at an operating point, a direct current gain of the resonance suppression controller, an inductance of a winding of a stator of the servo motor part, a pole constant of the servo motor part, a stator winding resistance of the servo motor part, and a rotor inertia moment of the servo motor part; a second servo motor feedback information storage unit that stores position and speed feedback information of the second servo motor generated when the second servo motor and the first servo motor are operated in parallel; a calculation unit that calculates an ineffective torque value to be transmitted to the power conversion unit, based on the data stored in the basic data storage unit and the feedback information of the first servomotor and the second servomotor stored in the second servomotor feedback information storage unit and the first servomotor feedback information storage unit; and a reactive torque command unit that outputs a reactive torque signal to transmit the calculated reactive torque value to the power conversion unit when the reactive torque value calculated by the calculation unit is not 0.

In another preferred embodiment of the resonance suppression control apparatus for a machine tool according to the present invention, the power conversion unit of the resonance suppression control apparatus for a machine tool adjusts the magnitudes of the current and the voltage applied to the first servomotor and the second servomotor, respectively, based on the signals transmitted to the effective torque command unit and the ineffective torque command unit, thereby suppressing resonance generated when the first servomotor and the second servomotor are operated in parallel.

In order to achieve another object of the present invention, a resonance suppression control method for a machine tool according to the present invention includes: storing information on a high-frequency gain limit value, a maximum value of a flux linkage of the corresponding permanent magnet, a natural frequency of the servo motor, an angular velocity at an operating point, a direct-current gain of the resonance suppression controller, an inductance of a winding of a stator of the servo motor, a pole constant of the servo motor, a stator winding resistance of the servo motor, and a rotor inertia moment of the servo motor in a basic data storage unit; a step of executing a control command at the PLC through communication with the numerical control part or the main operation part; a step of executing a control command transmitted from the PLC at a servo driver; a step in which a power conversion unit applies electric power to a servo motor unit including a first servo motor and a second servo motor, based on a signal from the servo driver; a step of storing, in a first servo motor feedback information storage unit, position and speed feedback information of the first servo motor generated when the first servo motor and the second servo motor are operated in parallel; a step of storing, in a second servo motor feedback information storage unit, position and speed feedback information of the second servo motor generated when the second servo motor and the first servo motor are operated in parallel; and a step of calculating an ineffective torque value transmitted to the power conversion unit at a calculation unit based on data stored in the basic data storage unit and feedback information of the first servo motor and the second servo motor stored in the second servo motor feedback information storage unit and the first servo motor feedback information storage unit, wherein the power conversion unit adjusts electric energy applied to the first servo motor and the second servo motor of the servo motor unit, respectively, based on the calculation value of the calculation unit, thereby suppressing resonance caused by controlling the operation of the servo motor unit.

In addition, in another preferred embodiment of the resonance suppression control method for a machine tool according to the present invention, the resonance suppression control method for a machine tool may further include, after the step of calculating: and comparing whether or not the reactive torque value calculated by the calculation unit is 0.

In addition, in a preferred other embodiment of the resonance suppression control method of a machine tool according to the present invention, the resonance suppression control method of a machine tool may further include, after the step of comparing: and a step of outputting a reactive torque signal to transmit the calculated reactive torque value to the power conversion unit when the reactive torque value is not 0.

Effects of the invention

According to the resonance suppression control device and the resonance suppression control method for the machine tool of the present invention, the electric energy applied to the first servomotor and the second servomotor is adjusted in the power conversion unit by the reactive torque command transmitted to the power conversion unit by the resonance suppression control unit, and the resonance generated when the two servomotors are operated in parallel is suppressed by one power conversion unit and one servo driver, thereby greatly improving the stability of the double drive control.

Further, the resonance suppression control device and the resonance suppression control method for a machine tool according to the present invention have the effect of suppressing resonance generated when two servo motors are operated in parallel in real time by one power unit and one power conversion unit, thereby eliminating unnecessary components, reducing the size of the servo control device, and greatly improving the space utilization rate.

Further, the resonance suppression control device and the resonance suppression control method for a machine tool according to the present invention have the effect of performing precise resonance suppression control of two servo motors in real time by suppressing resonance generated when the two servo motors are operated in parallel in real time by one power unit and a power conversion unit based on the feedback information of the first and second servo motors transmitted in real time from the first and second servo motor feedback information storage units, thereby greatly improving the precision and reliability of the servo control device of the automatic tool changer or the automatic pallet changer and increasing the productivity and the machining efficiency of the machine tool.

Further, the resonance suppression control device and the resonance suppression control method for a machine tool according to the present invention have the effect of automatically suppressing resonance generated when two servo motors are operated in parallel in real time by one power unit and a power conversion unit, thereby achieving operator's convenience, minimizing non-machining time, and greatly improving productivity of the machine tool.

Drawings

Fig. 1 shows a conceptual diagram of a multi-inverter multi-servo motor in which one inverter and one servo driver are combined with one conventional servo motor.

Fig. 2 is a conceptual diagram showing a single inverter multi-servo motor that performs dual drive control by combining one inverter and one servo driver with two conventional servo motors.

Fig. 3 is a block diagram of the structure of a resonance suppression control apparatus of a machine tool according to an embodiment of the present invention.

Fig. 4 is a block diagram of a configuration of a resonance suppression control section of a servo driver of a resonance suppression control apparatus of a machine tool according to an embodiment of the present invention.

Fig. 5 is a step diagram of a resonance suppression control method of a machine tool according to an embodiment of the present invention.

Fig. 6 and 7 are graphs illustrating the effect of the resonance suppression control by the resonance suppression control apparatus and the resonance suppression control method for the machine tool according to the embodiment of the present invention.

Detailed Description

Hereinafter, a resonance suppression control apparatus and a resonance suppression control method of a machine tool according to an embodiment of the present invention will be described in detail with reference to the drawings. The embodiments described below are provided as examples in order to fully convey the concept of the present invention to those skilled in the art. Therefore, the present invention is not limited to the embodiments described below, and may be embodied in other forms. In the drawings, the size, thickness, and the like of the device may be enlarged for convenience. Throughout the specification, the same reference numerals denote the same constituent elements.

The advantages, features and methods of accomplishing the same may become apparent from the following detailed description of the embodiments when taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be configured in various forms different from each other, and the embodiments are provided only to make the disclosure of the present invention complete and to fully inform the scope of the invention to those having ordinary knowledge in the art to which the present invention pertains, and the present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity of illustration.

The terms used in the specification are used for describing the embodiments, and thus are not used for limiting the present invention. In this specification, the singular forms also include the plural forms unless otherwise specified in the sentence. The term "comprises" and/or "comprising" as used in this specification is intended to mean that the recited components, steps, actions, and/or elements do not preclude the presence or addition of one or more other components, steps, actions, and/or elements.

Fig. 3 is a block diagram showing the configuration of a resonance suppression control device for a machine tool according to an embodiment of the present invention, fig. 4 is a block diagram showing the configuration of a resonance suppression control unit of a servo driver of the resonance suppression control device for a machine tool according to an embodiment of the present invention, fig. 5 is a step diagram showing a resonance suppression control method for a machine tool according to an embodiment of the present invention, and fig. 6 and 7 are graphs illustrating the effects of resonance suppression control by the resonance suppression control device and the resonance suppression control method for a machine tool according to an embodiment of the present invention.

A resonance suppression control device 1 for a machine tool according to an embodiment of the present invention will be described with reference to fig. 3 and 4. As shown in fig. 3 and 4, a resonance suppression control device 1 for a machine tool according to an embodiment of the present invention includes a numerical control unit 100, a main operation unit 200, a PLC (programmable logic controller)300, a servo driver 400, a servo motor unit 600, and a power conversion unit 500.

The numerical control unit 100 includes an NC (numerical control) or a CNC (computerized numerical control), and stores therein various numerical control programs. That is, a drive program of the servo motor, an operation program of the tool, and the like are stored in the numerical control unit 100, and the program is automatically loaded and started as the numerical control unit is driven. The numerical control unit 100 communicates with the main operation unit 200, the PLC300, and the servo driver 400 by a predetermined protocol.

The numerical control unit 100 transmits feedback information from the first servomotor 610 or the second servomotor 620 of the servomotor unit 600 for driving an Automatic Tool Changer (ATC) or an Automatic Pallet Changer (APC). More specifically, the numerical control unit 100 transmits feedback information on the position and speed of the first servo motor 610 or the second servo motor 620 from a first servo motor feedback information storage unit 440 or a second servo motor feedback information storage unit 432, which will be described later.

The main operation unit 200 includes a screen display program and a data input program selected based ON the screen display, and displays a software switch ON a display screen in accordance with the output of the screen display program, and recognizes ON/OFF of the software switch, thereby executing a function of issuing an input/output instruction of a machine tool operation.

The main operation unit 200 includes a display, is provided on a housing, a case, or one side of the machine tool, and can display various kinds of function switches, buttons, and various kinds of information, but is not limited thereto.

A PLC (Programmable Logic Controller)300 communicates with the numerical control unit 100 or the main operation unit 200 by a predetermined protocol, and performs a function of executing a control command by the communication. That is, the PLC300 receives a control command and operates by a numerical control program of the numerical control unit 100 or the main operation unit 200.

After the numerical control unit 100 or the master operation unit 200 transmits and executes the control command, the PCL300 outputs the control command to the numerical control unit 100, and transmits the control command to the servo driver 400 through the master operation unit 200. The PLC300 may transmit a control command from the user to the servo driver 400 in real time through the main operation unit 200 as needed.

The servo driver 400 executes a control command of the PLC 300. That is, the servo driver 400 controls the driving of a servo motor of the servo motor unit 500, which will be described later, by a control command of the PLC300, and finally controls the driving of various parts of the machine tool driven by the servo motor, such as an Automatic Tool Changer (ATC) or an Automatic Pallet Changer (APC), a tailstock, and a vibration damping device, which are driven by the servo motor. The servo driver 400 transmits the control result to the PLC300 through a contact or communication based on a predetermined protocol.

In addition, the servo driver 400 transmits feedback information from the first servo motor 610 or the second servo motor 620 of the servo motor section 600 for driving an Automatic Tool Changer (ATC) or an Automatic Pallet Changer (APC). More specifically, the numerical control unit 100 transmits feedback information on the position and speed of the first servo motor 610 or the second servo motor 620 from a first servo motor feedback information storage unit 440 or a second servo motor feedback information storage unit 432, which will be described later.

The servo motor section 600 is driven by the control of the servo driver 400.

As shown in fig. 3, a servo motor unit 600 of the servo control device 1 of the machine tool according to the embodiment of the present invention includes a first servo motor 610 and a second servo motor 620.

The first servo motor 610 and the second servo motor 620 are connected in parallel to the power conversion unit 500, which will be described later, and are operated in parallel by electric energy applied to the power conversion unit 500 in response to a control signal of the servo driver.

The servo motor unit 600 is driven by the first servo motor 610 or the second servo motor 620 in accordance with the corresponding sequence information and the position information or the program under the control of the servo driver 400.

The power conversion unit 500 is electrically connected to the servo motor unit 600 and the servo driver 400. In addition, the power conversion unit 500 applies electric energy to the servo motor unit 600 in accordance with a contact signal of the servo driver 400.

As described above, the resonance suppression control apparatus for a machine tool according to the present invention suppresses resonance generated when the first servo motor 610 and the second servo motor 620 controlling the servo motor unit 600 are operated in parallel by adjusting the electric energy applied to the servo motor unit 600 by the power conversion unit 500 according to the signal of the servo driver 400. Specifically, the power conversion unit 500 transmits an effective torque command and an ineffective torque command signal applied to the servo driver, and the power conversion unit 500 varies the current and voltage applied to each of the first servo motor 610 and the second servo motor 620 to adjust the electric energy applied to each of the first servo motor 610 and the second servo motor 620 in real time, thereby suppressing resonance generated when the first servo motor 610 and the second servo motor 620 are controlled to operate in parallel.

Therefore, according to the resonance suppression control device for a machine tool of the present invention, the electric power applied to the first servo motor and the second servo motor is adjusted in the power conversion unit by transmitting the reactive torque command to the power conversion unit through the servo driver, and the resonance generated when the two servo motors are operated in parallel is suppressed by one power conversion unit and one servo driver, so that the stability of the double drive control is greatly improved, and finally, the manufacturing cost of the servo control device can be saved and the compatibility can be increased by controlling the automatic tool changer or the automatic pallet changer.

As shown in fig. 3, the servo driver 400 of the resonance suppression control apparatus 1 for a machine tool according to an embodiment of the present invention includes: a speed command unit 410, an effective torque command unit 420, a resonance suppression control unit 430, and a first servo motor feedback information storage unit 440.

Although not shown, the servo driver 400 of the resonance suppression control apparatus for a machine tool may further include a controller as necessary. The controller is provided inside the servo driver 400, and stores therein a detailed control command interpretation program, various machining programs, and a drive program. The controller communicates with the numerical control unit 100, the main operation unit 200, the PLC300, 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 a control command of the main operation unit to the servo driver 400 through the PLC300 without passing through the numerical control unit 100.

As described above, since the detailed control command interpretation program or the separate control program is entirely stored in the controller of the servo driver 400 described later, the servo driver 400 may drive the servo motor 600 described later by executing the commands from the main operation unit 200 and the PLC300 without receiving the driving command of the servo motor 500 from the numerical control unit 100.

Therefore, the controller of the servo driver 400 can execute a detailed control command performed in the numerical control unit 100, and only the protocol function is programmed with the other numerical control unit to execute the servo driver function, whereby a plurality of programs can be driven by the servo driver, and the compatibility of the apparatus can be greatly improved, and convenience of the user can be achieved.

The speed command unit 410 outputs an operation speed signal of the servo motor unit 600 based on the position command transmitted from the numerical control unit 100 and the feedback signal of the first servo motor 610 transmitted from the first servo motor feedback information storage unit 440.

Specifically, the speed command unit 410 outputs the operation speed signal of the servo motor unit 600 based on the position command first transmitted from the numerical control unit 100 in a state before the first servo motor 610 and the second servo motor 620 are operated in parallel at the time of initial driving of the servo control device. Then, feedback information of the first servo motor 610 generated when the first servo motor 610 and the second servo motor 620 of the servo motor part 600 are operated in parallel is transmitted to the first servo motor feedback information storage part 440 according to the speed command outputted from the speed command part 410, and after the initial driving, an operation speed signal of the servo motor part 600 is outputted based on the feedback signal transmitted from the first servo motor feedback information storage part 440 and the position command transmitted from the numerical control part 100.

The effective torque command unit 420 outputs an effective torque signal to be transmitted to the power conversion unit 500 based on the speed command transmitted from the speed command unit 410 and the feedback signal transmitted from the first servo motor feedback information storage unit 440, to drive the servo motor unit 600.

Specifically, at the time of initial driving of the servo control device, the effective torque command unit 420 outputs the effective torque signal to be transmitted to the power conversion unit 500 based on the speed command transmitted from the first speed command unit 410 in a state before the first servo motor 610 and the second servo motor 620 are operated in parallel, to drive the servo motor unit 600. Then, feedback information of the first servo motor 610 generated when the electric power conversion unit 500 drives the first servo motor 610 and the second servo motor 620 of the servo motor unit 600 to operate in parallel is transmitted to the first servo motor feedback information storage unit 440 based on the effective torque signal output from the effective torque command unit 420, and after the initial driving, the effective torque signal transmitted to the electric power conversion unit 500 is output based on the feedback signal transmitted from the first servo motor feedback information storage unit 440 and the operation speed signal transmitted from the speed command unit 410.

After the initial driving of the servo control device, the resonance suppression control unit 430 outputs an ineffective torque signal to be transmitted to the power conversion unit 500 after the parallel operation of the first servo motor 610 and the second servo motor 620 of the servo motor unit 600, and performs a function of suppressing resonance generated when the parallel operation of the first servo motor 610 and the second servo motor 620 is controlled.

First servo motor feedback information storage unit 440 stores position and velocity feedback information of first servo motor 610 generated when first servo motor 610 and second servo motor 620 are operated in parallel.

The speed command unit 410, the effective torque command unit 420, the resonance suppression control unit 430, and the first servo motor feedback information storage unit 440 are provided inside the servo driver 400, and may separately store therein a detailed control command interpretation program, various machining programs, and a drive program. The speed command unit 410, the effective torque command unit 420, the resonance suppression control unit 430, and the first servo motor feedback information storage unit 440 may communicate with the numerical control unit 100, the main operation unit 200, the PLC300, the servo motor unit 600, and the power conversion unit 500 by a predetermined protocol.

Therefore, the resonance suppression control device for a machine tool according to the present invention suppresses resonance generated when two servo motors are operated in parallel in real time by one power unit and one power conversion unit, thereby eliminating unnecessary components, reducing the size of the servo control device, and greatly improving the space utilization rate.

As shown in fig. 4, the resonance suppression control unit 430 of the servo driver 400 of the resonance suppression control apparatus 1 for a machine tool according to the embodiment of the present invention includes a basic data storage unit 431, a second servo motor feedback information storage unit 432, a calculation unit 433, and a reactive torque command unit 434.

The basic data storage unit 431, the second servomotor feedback information storage unit 432, the arithmetic unit 433, and the reactive torque command unit 434 are provided inside the resonance suppression control unit 430, and may separately store therein a detailed control command interpretation program, various machining programs, and a drive program. The basic data storage unit 431, the second servo motor feedback information storage unit 432, the arithmetic unit 433, and the reactive torque command unit 434 may communicate with the numerical control unit 100, the main operation unit 200, the PLC300, the servo motor unit 600, the power conversion unit 500, the speed command unit 410, the reactive torque command unit 420, and the first servo motor feedback information storage unit 440 via a predetermined protocol.

The basic data storage unit 431 stores information on a high frequency gain limit value, a maximum value of a flux linkage of a corresponding permanent magnet, a natural frequency of the servo motor unit, an angular velocity at an operating point, a direct current gain of the resonance suppression controller, an inductance of a winding of a stator of the servo motor unit, a pole constant of the servo motor unit, a stator winding resistance of the servo motor unit, and a rotor inertia moment of the servo motor unit.

The basic data may be stored by an operator through the numerical control unit 100 or the main operation unit 200, or may be stored in the PLC300 in the form of a program.

Second servo motor feedback information storage section 432 stores position and speed feedback information of second servo motor 620 generated when second servo motor 620 and first servo motor 610 are operated in parallel.

As described above, the second servo motor feedback information storage part 432 is electrically connected to the speed command part 410, the effective torque command part 420, the first servo motor feedback information storage part 440, and the like, and can perform communication by a predetermined protocol.

The arithmetic unit 433 calculates the reactive torque value to be transmitted to the power conversion unit 500 from the data stored in the basic data storage unit 431 and the feedback information of the first servomotor 610 and the second servomotor 620 stored in the second servomotor feedback information storage unit 432 and the first servomotor feedback information storage unit 440.

When the reactive torque value calculated by the calculation unit 433 is not 0, the reactive torque command unit 434 outputs a reactive torque signal to transmit the calculated reactive torque value to the power conversion unit 500. Reactive torque command unit 434 is electrically connected to power conversion unit 500, effective torque command unit 420, and the like, and communicates with each other by a predetermined protocol.

Therefore, according to the resonance suppression control device for a machine tool of the present invention, the resonance generated when the two servo motors are operated in parallel is suppressed and controlled in real time by the power unit and the power conversion unit based on the feedback information of the first and second servo motors transmitted in real time from the first and second servo motor feedback information storage units, thereby performing precise resonance suppression control of the two servo motors in real time, and thus, the precision and reliability of the servo control device with the automatic tool changer or the automatic pallet changer can be greatly improved, and the productivity and the machining efficiency of the machine tool can be increased.

The calculation unit 433 of the resonance suppression control unit 430 calculates the reactive torque value to be transmitted to the power conversion unit 500 to suppress resonance by the following principle.

Under normal state, changing the state variable from X to X₀And the expression of +/-Delta X is obtained by calculating the linearized state equation by using Taylor series and calculating the linearized state equation by using the mathematical formula 1.

Mathematical formula 1

However, in the formula 1, the servo control device for parallel operation is very complicated in order to evaluate the stability.

Therefore, in order to simplify equation 1, equation 1 is calculated from equation 2, assuming that the mechanical time constant of the servo motor is sufficiently larger than the electrical time constant, and the equation 1 is arranged.

Mathematical formula 2

Therefore, when the transfer function is obtained from equation 2, equation 3 is obtained.

Mathematical formula 3

In equation 3, which is a characteristic equation of the transfer function, the damping coefficient of the servo control devices operating in parallel and the frequency at which resonance occurs are calculated from equation 4.

Mathematical formula 4

In the servo control device operated in parallel operation by the dual drive control calculated by the equation 4, the equation in the calculation unit of the resonance suppression control unit is finally calculated by the equation 5.

Mathematical formula 5

That is, the calculation unit 433 of the resonance suppression control unit 430 calculates the reactive torque value transmitted to the power conversion unit from the feedback information of the first servomotor and the second servomotor, by the above equation 5. In which alpha is used to limit the gain value in the high frequency region₁Time constant T with maximum sum phase₁The gain can be directly obtained from equation 4, and thus the trial and error due to the gain determination of the resonance suppression control unit can be fundamentally reduced.

The factors in the above mathematical formulae 1 to 5 are as follows.

α: high frequency gain limit

i：V_tAnd E_tAngle of torque therebetween

δ: torque angle in transition state

Delta.: linearized torque angle

Δ u: input variable variation component

Δ x: component of state variable fluctuation

Linearized rotor angular velocity

c: damping constant

θ: arbitrary rotor position

λ_uvw: flux linkage of stator winding

Φ_d: pore magnetic flux

Φ_t: maximum value of flux linkage by corresponding permanent magnet

Φ_m: magnetic flux of permanent magnet

Φ_max: maximum phase

Φ_s: armature reaction flux

φ：V_tAnd I_dAngle of power factor therebetween

ψ：I_dAnd E_tInternal power angle therebetween

ω_n: natural frequency of the system

ω_max: maximum phase frequency

ω_o: angular velocity at the point of action

Angular speed of rotor

Arbitrary angular velocity

ω_s: synchronous angular velocity

E_t: excitation voltage

Excitation voltage in transient state

I_α: armature current

i_uvw: three-phase current

Rotating coordinate system d^r-q^rShaft stator current

Arbitrary coordinate system d^ω-q^ωShaft stator current

Rotating coordinate system d^r-q^rShaft stator command current

Arbitrary coordinate system d^ω-q^ωShaft stator command current

K_x: attenuation gain

K_θ(θd): curve of linear function

K_i: DC gain of resonance suppression controller

L_s: inductance of motor stator winding

P_t: pole constant of motor

R_s: resistance of motor stator winding

T: mechanical output torque in transient state

T_max: transition formMaximum value of mechanical output torque in state

Rotating coordinate system d^r-q^rOutput torque of shaft

Arbitrary coordinate system d^ω-q^ωOutput torque of shaft

T_L: load torque

T_i: maximum phase time constant

V_t: terminal voltage

V_uvw: three-phase voltage

V^* _dq: voltage command of d, q axis

Synchronous reactance in transition state

X: variable of state

X_o: state variables at action points

X_s: synchronous reactance

J: moment of inertia of motor rotor

S：α+jω

At S: in α + j ω, α is a real number, j ω is an imaginary number, and S is a factor showing the magnitude and phase in the frequency space.

As described above, according to the resonance suppression control device for a machine tool of the present invention, the operation unit precisely and quickly calculates the reactive torque command in real time based on the feedback information of the first servomotor and the second servomotor in accordance with the parallel operation of the first servomotor and the second servomotor to suppress the resonance generated when the two servomotors are operated in parallel, so that the electric power conversion unit adjusts the magnitudes of the current and the voltage to be transmitted to the first servomotor and the second servomotor, respectively, to suppress the resonance generated when the parallel operation is controlled, thereby achieving the convenience of the operator, reducing the damage or breakage of the servo control device due to the generation of the resonance, minimizing the non-machining time, greatly improving the productivity of the machine tool, and greatly improving the reliability and stability of the machine tool.

The power conversion unit 500 adjusts the intensities of the current and the voltage applied to the first servo motor 610 and the second servo motor 620, respectively, based on the signal transmitted to the reactive torque command unit 434 by the effective torque command unit 420 and the reactive torque value calculated by the calculation unit 433, thereby most effectively and accurately suppressing the resonance generated when the first servo motor 610 and the second servo motor 620 are operated in parallel in real time.

Therefore, the resonance suppression control device for a machine tool according to the present invention automatically suppresses resonance generated when two servo motors are operated in parallel in real time by one power unit and one power conversion unit, thereby achieving operator's convenience, minimizing non-machining time, and greatly improving productivity of the machine tool.

Further, although not shown, the resonance suppression control device 1 for a machine tool according to an embodiment of the present invention may further include an input unit and a display unit.

The input unit is provided in the form of a switch or a touch button on an operation panel or a main operation unit, and executes a function that can be arbitrarily selected by an operator to perform resonance suppression control in real time or not when the servo motor units are operated in parallel.

That is, when the two servo motors of the servo motor unit of the servo control device of the machine tool are operated in parallel and the resonance suppression control device function is not selected in the input unit, the servo control device of the machine tool does not operate the resonance suppression control function.

The display unit displays the reactive torque value of the calculation unit, the effective torque value of the effective torque command unit, the current machining program, the type of the workpiece, and the like. Therefore, an operator can confirm whether resonance suppression and control states exist when two servo motors of the servo motor part are operated in parallel in real time by naked eyes.

The display unit may be configured by an LCD, an LED, a PDP display, or the like in the main operation unit or the numerical control unit, but is not necessarily limited thereto.

As shown in fig. 5, a resonance suppression control method of a machine tool according to a preferred embodiment of the present invention includes: a step S1 of storing the basic data; step S2 in which the PLC executes the control command; step S3 executed at the servo driver; a step S4 of applying electric energy to the servo motor unit by the electric power conversion unit; a step S5 of storing first servo motor feedback information; a step S6 of storing second servo motor feedback information; a step S7 of calculating an ineffective torque; step S8 of comparing whether or not the reactive torque value is 0; and a step S9 of transmitting the reactive torque command. The specific execution or content of the apparatus in each step is the same as that of the resonance suppression control apparatus for a machine tool in the specification of the present invention, and therefore, the following description focuses on a special point of the resonance suppression control method for a machine tool.

The basic data storage unit 431 stores therein information on a high frequency gain limit value, a maximum value of a flux linkage of the corresponding permanent magnet, a natural frequency of the servo motor unit, an angular velocity at an operating point, a dc gain of the resonance suppression controller, an inductance of a winding of a stator of the servo motor unit, a pole constant of the servo motor unit, a stator winding resistance of the servo motor unit, and a rotor inertia moment of the servo motor unit. The basic data may be stored by an operator through the numerical control unit 100 or the main operation unit 200, or may be stored in the PLC300 in the form of a program.

After step S1, which is stored in the basic data storage unit, the PLC300 executes a control command by communicating with the numerical control unit 100 or the main operation unit 200.

After step S2 in which the PCL executes the control command, the servo driver 400 executes the control command transmitted from the PLC 300.

After step S3 executed by the servo driver, the power conversion unit 500 applies electric power to the servo motor unit 600 including the first servo motor 610 and the second servo motor 620 in accordance with the signal of the servo driver 400. Specifically, the electric power conversion unit 500 transmits the calculated electric energy to the first servo motor 610 and the second servo motor 620. As described above, since resonance does not occur in accordance with parallel operation of the first servo motor and the second servo motor when the servo control device is initially driven, electric energy is initially applied to the first servo motor 610 and the second servo motor 620 through the power conversion unit 500 in accordance with a machining program or a control protocol in the numerical control unit, the main operating panel, or the PLC.

After step S4 in which the power conversion unit applies electric power to the servo motor unit, the position and speed feedback information of the first servo motor 610 generated when the first servo motor 610 and the second servo motor 620 are operated in parallel is stored in the first servo motor feedback information storage unit 440.

After step S5 in which the first servo motor feedback information is stored, the position and speed feedback information of the second servo motor 620 generated when the second servo motor 620 is operated in parallel with the first servo motor 610 is stored in the second servo motor feedback information storage unit 432.

After step S6 of storing the second servo motor feedback information, the arithmetic unit 433 calculates an ineffective torque value transmitted to the power conversion unit 500 by the data stored in the basic data storage unit 431 and the feedback information of the first servo motor 610 and the second servo motor 620 stored in the second servo motor feedback information storage unit 432 and the first servo motor feedback information storage unit 440 by equation 5.

After the step S7 of calculating the reactive torque, it is compared whether or not the reactive torque value calculated by the calculation unit 433 is 0.

After step S8 of comparing whether or not the reactive torque value is 0, when the reactive torque value is not 0, the reactive torque command portion 434 outputs a reactive torque signal to transmit the calculated reactive torque value to the power conversion portion 500.

The power conversion unit adjusts the electric energy applied to each of the first and second servo motors of the servo motor unit based on the calculated value of the calculation unit, thereby suppressing resonance caused by controlling the operation of the servo motor unit.

That is, the power conversion unit 500 adjusts the electric energy, i.e., the intensity of the current and the voltage, applied to each of the first servo motor 610 and the second servo motor 620 of the servo motor unit 600 based on the effective torque value transmitted to the effective torque command unit 420 and the ineffective torque value transmitted to the ineffective torque command unit 434, thereby suppressing the resonance and accurately and rapidly suppressing the resonance generated when the two servo motors are controlled to operate in parallel in real time.

Therefore, according to the resonance suppression control method for a machine tool of the present invention, the electric power applied to the first servomotor and the second servomotor is adjusted in the power conversion unit by transmitting the reactive torque command to the power conversion unit by the resonance suppression control unit, and the resonance generated when the two servomotors are operated in parallel is suppressed by one power conversion unit and one servo driver, whereby the stability of the double drive control is greatly improved, and finally the manufacturing cost of the servo control device can be saved and the compatibility can be increased by controlling the automatic tool changer or the automatic pallet changer.

The resonance suppression control apparatus and the resonance suppression control method for a machine tool according to the present invention will be described in more detail with reference to fig. 6 and 7. Fig. 6 is a bode diagram showing a change in vibration amount based on frequency, and fig. 7 is a bode diagram showing a phase difference based on frequency. In fig. 6 and 7, the solid line indicates a case where two servo motors are operated in parallel in the conventional servo control device, and the broken line indicates a state where the resonance suppression control device and the resonance suppression control method for the machine tool according to the present invention are applied.

As is apparent from fig. 6 and 7, the servo control device using the conventional dual drive control generates resonance, and the phase is also approximately 9 degrees with respect to 180 degrees. In contrast, when the resonance suppression control device and the resonance suppression control method for a machine tool according to the present invention are applied, resonance is completely suppressed without an inflection point and a phase is displayed at 60 degrees with respect to 180 degrees. Finally, compared with the prior art, the resonance suppression control device and the resonance suppression control method for the machine tool can guarantee the stability and the reliability of more than 6 times.

That is, according to the resonance suppression control device and the resonance suppression control method for a machine tool of the present invention, the calculation unit calculates the reactive torque value in real time by the equation 5, and transmits the reactive torque signal together with the effective torque signal to the power conversion unit, and the power conversion unit controls the electric energy applied to each of the first servo motor and the second servo motor in parallel operation in real time, thereby ensuring stability and reliability of approximately 6.2 times against disturbance.

While the present invention has been described in detail with reference to the preferred embodiments thereof, it will be apparent to one skilled in the art or persons having ordinary skill in the art that various modifications and changes can be made thereto without departing from the spirit and scope of the present invention as set forth in the claims. Therefore, the technical scope of the present invention is not limited by the contents described in the detailed description of the specification, but is defined by the claims.

Description of the symbols:

1: resonance suppression control device, 10: first servo driver, 11: second servo driver, 20: first inverter, 21: second inverter, 30: first servo motor, 31: second servo motor, 100: numerical control unit, 200: main operation portion, 300: PLC, 400: servo driver, 410: speed command unit, 420: effective torque command unit, 430: resonance suppression control unit, 431: basic data storage unit, 432: second servo motor feedback information storage section, 433: arithmetic unit, 434: reactive torque command unit, 440: first servo motor feedback information storage, 500: power conversion unit, 600: servo motor portion, 610: first servo motor, 620: a second servo motor.