Three-coordinate motion system control device

Abstract

FIELD: electrical engineering.SUBSTANCE: invention can be used to control a three-coordinate movement system, where stepper motors are used as drives, and the working elements can be spindles, extruders, measuring heads, etc. The control device for the three-coordinate movement system includes three integrated stepper servo drives, connected respectively to three linear movement modules, which ensure movement of the working element along three axes. Each of the servo drives comprises a control unit comprising a programmable logic controller and a frequency converter with a driver, a stepper motor connected to the frequency converter with a driver, and an encoder connected to the linear motion module and transmitting data to the control unit. The programmable logic controller is configured to be connected to a control computer.EFFECT: contactless movement of the working element and increased accuracy of positioning the working element during movement by controlling the movement mode of the stepper motor.1 cl, 1 dwg

Description

[0001] The invention relates to the field of mechanical engineering and can be used to control a three-coordinate movement system, where stepper motors are used as drives, and the working elements (WE) can be spindles, extruders, measuring heads, etc.

[0002] A three-coordinate positioner is known (RU Patent 2297078 C1, published November 8, 2005. IPC: H01L 41 / 09), which consists of an object holder and a housing. Three actuators are fixed to the housing, each containing at least one bimorphic element connected via a first flexible pusher to a movable element. The bimorphic elements are packages, each containing a piezoelectric disk connected along a plane to a metal membrane. The object holder is mounted on the movable element. The object holder can be mounted on the movable element by means of a lever. The pushers have different rigidity. The piezoelectric disks and metal membranes have openings in the area of ​​their connection to the flexible pushers.

[0003] The common features of the known and claimed technical solutions are the use of three drives (motors) for the arrangement of the working element in space - its positioning.

[0004] However, the known device does not provide quick and easy adjustment of the motion mode of each drive, which will lead to a decrease in the positioning accuracy of the working element. Other disadvantages of this device include limited functionality due to the difficulty of setting the motion coordinates, as well as the complexity of the design.

[0005] A three-coordinate drive is known (patent application of the Russian Federation 2001102120 C2, published on 20.12.2002, IPC: H01H 63 / 22), comprising a kinematic transmission coupled with motors and a plurality of parallel-arranged actuator threaded posts fixed against rotation and provided with nuts fixed against longitudinal displacement, and a plurality of coupling elements with said transmission, characterized in that it is supplemented by units: four-parameter memory, reversible control, input and correction, and a multi-input logical element. The units can be made in various versions.

[0006] Common features are: connection to engines, use of control unit.

[0007] However, the known design is complex and does not allow for quick and easy control of the movement mode of stepper motors for positioning the working element.

[0008] The closest analogue (prototype) is a three-coordinate movement device (RU patent 2548163, published 04 / 20 / 2015, IPC: H02K 33 / 02, B25J 9 / 12), containing a control unit, a housing, an electromechanical converter, characterized in that the electromechanical converter is made in the form of a three-coordinate electromechanical motor containing an induction system of movable and fixed parts, wherein the movable part is made in the form of four bipolar permanent magnets fixed on elastic rods and installed with an angular offset relative to the fixed part, and the fixed part consists of four coils placed along the perimeter of the housing.

[0009] Common features of the known and claimed technical solutions are the presence of a control unit and a motor for three-coordinate movement.

[0010] However, control is carried out using a single motor, the known design does not provide easy control of the speed of movement of each of the elements to place the working body in the desired coordinates.

[0011] The objective of the invention is to provide the ability to control the speed (mode of movement of the stepper motor) during movement to improve the accuracy of positioning of the working element.

[0012] The technical result is to ensure the possibility of contactless movement of the working element and to increase the accuracy of positioning of the working element during movement by controlling the movement mode of the stepper motor.

[0013] The technical result is achieved by using a control device for a three-coordinate movement system, which includes three integrated stepper servo drives, connected respectively to three linear movement modules, which ensure the movement of the working element, wherein each of the servo drives is configured to be connected to a control computer, includes a control unit containing a frequency converter with a driver and a programmable logic controller and connected to a stepper motor, and an encoder.

[0014] This design of the device allows for control of the system of movement of working bodies to improve the accuracy of their positioning using stepper motors.

[0015] Integrated stepper servo drives control linear motion modules. A signal from the host computer is sent to the programmable controller in the servo drive control unit, and a frequency converter converts the signal into a frequency for stepper motor control. Data from the linear motion module is recorded by an encoder and transmitted to the control unit. This allows for monitoring the correct motion path of the working element, which is moved using a three-axis motion system.

[0016] The use of this design allows changing the speed of movement of stepper motors in a time cycle (the time during which the steps of each stepper motor will be executed when moving along a prescribed trajectory), which in turn allows increasing the accuracy of positioning of the working element while maintaining contactless control.

[0017] The essence of the invention is explained by drawings. Figure 1 shows a structural diagram of a variant of a control device for a three-coordinate movement system, where

[0018] 1 - control computer

[0019] 2 - Integrated stepper servo drive

[0020] 3 - stepper motor

[0021] 4 - encoder

[0022] 5 - control unit

[0023] 6 - Programmable Logic Controller

[0024] 7 - frequency converter with driver

[0025] 8 - linear motion module (channel)

[0026] 9 - control channel

[0027] 10 - control channel

[0028] X, Y, Z - transmission of a control signal to the corresponding stepper motor, ensuring the movement of the working element in the specified coordinates.

[0029] A three-coordinate movement control device that includes three integrated stepper servo drives (2) connected to three linear movement modules (8) respectively, which provide movement of the working element, wherein each of the servo drives is configured to be connected to a control computer (1), includes a control unit (5) containing a frequency converter with a driver (7) and a programmable logic controller (6) and connected to a stepper motor (3), and an encoder (4). The linear movement modules provide direct movement of the working element along the X, Y, Z axes, respectively, and are controlled by servo drive 2. Control channels 9 and 10 along the Y and Z axes have a structure similar to the control structure along the X axis (not shown in detail in the figure).

[0030] The three-coordinate movement device operates as follows.

[0031] The control computer determines the motion trajectory of the working element, such as the print head of a 3D printer, based on a model of the object (a 3D model of the product being manufactured). The control computer sends a signal to the integrated stepper servo drive control unit, where it is converted into a frequency signal to control the stepper motor. The frequency signal, determined based on the selected stepper motor operating mode, is fed to the linear motion module, which drives the working element. This allows for quick and easy adjustments to the stepper motor operating mode, such as microstepping, which improves positioning accuracy. The combination of microstepping and full-stepping modes per control cycle simultaneously ensures positioning accuracy and maintains dynamic operation.

Claims

A control device for a three-coordinate movement system, characterized in that it includes three integrated stepper servo drives, connected respectively to three linear movement modules, which ensure the movement of the working element along the X, Y, Z axes, respectively, wherein each of the servo drives contains a stepper motor, an encoder and a control unit containing a programmable logic controller (PLC), configured with the possibility of connecting to a control computer, and a frequency converter with a driver, which is connected to the stepper motor, wherein the input of the encoder is connected to the linear movement module, and its output is connected to the PLC in the control unit for data transmission.

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