A macro-micro linear actuator based on GMM

Abstract

The present invention relates to a macro-micro linear driver based on GMM, comprising a shell, a permanent magnet, a yoke 1, a fastening screw, a micro-motion coil, a GMM rod, an output rod, a mover bracket, a fixed base, a linear guide rail, a grating, a water-cooling pipe, a micro-motion coil skeleton, a linear rolling bearing, a sliding rod, a yoke 2, a magnetic isolation sleeve, a macro-motion coil, and a limit groove; the macro-motion coil is energized to generate a Lorentz force, which causes the mover to move axially in a stable magnetic field provided by the permanent magnet to obtain a macro displacement, the magnitude of the Lorentz force is proportional to the magnitude of a current in a conductive material, and the macro displacement is adjusted by controlling the current, the macro-motion system is in a stationary state after the initial positioning is completed, the micro-motion system performs compensation control according to the detected system error to achieve secondary positioning, current is passed through the micro-motion coil to generate a stable magnetic field around the GMM rod, the GMM rod is extended axially under the action of the magnetic field to obtain a micro displacement, and the positioning accuracy of the macro motion is compensated, thereby achieving precise positioning of the entire motion.

Description

Technical Field

[0001] The present invention relates to the field of precision positioning, and in particular to a macro-micro linear driver based on GMM. Background Art

[0002] Ultra-precision feed systems with high precision and large strokes occupy an extremely important position in the fields of modern cutting-edge industrial production and scientific research. They can greatly improve the machining accuracy of ultra-precision machine tools, and are of great significance to improving the development of my country's national economy, narrowing the gap between my country and developed countries in the field of ultra-precision machining and testing, and accelerating the modernization of the national defense industry. The giant magnetostrictive actuator (Giant Magnetostrictive Actuator, GMA) is a micro-displacement output device that converts electromagnetic energy into mechanical energy based on the positive magnetostrictive effect and giant magnetostrictive material (GMM) as the core driving element. It not only overcomes the shortcomings of traditional displacement drive devices, but also has a higher magneto-mechanical conversion efficiency that is unmatched by other functional materials. With its excellent characteristics such as large output force, wide operating frequency (0-100KHz), microsecond response speed, and high-precision control. However, due to the performance of the giant magnetostrictive material itself, the maximum driving stroke of the giant magnetostrictive actuator is small, generally less than 0.2mm, far from the requirement of large stroke.

[0003] By applying permanent magnet drive technology to GMA design, a new type of large-stroke macro-micro actuator is obtained, which combines macro motion and micro motion together, which can meet both the performance of precise positioning and the performance of large stroke, thereby improving the overall performance of the actuator. Summary of the invention

[0004] The purpose of the present invention is to provide a macro-micro linear actuator based on GMM to further improve the working stroke of GMA, broaden its application field, and reduce the influence of temperature change caused by the inherent hysteresis characteristics and eddy current characteristics of GMM on the output accuracy of GMA.

[0005] The basic concept of the macro-micro composite drive platform is to use a small-stroke, high-precision micro-motion platform to compensate for the motion error of a large-stroke, coarse-precision macro-motion platform, and ultimately achieve a large-stroke, high-precision macro-micro composite motion.

[0006] The present invention adopts the following technical solutions to achieve the purpose of the invention:

[0007] A macro-micro linear actuator based on GMM, the specific product comprises a shell (1), a permanent magnet (2), a yoke 1 (3), a fastening screw (4), a micro-motion coil (5), a GMM rod (6), an output rod (7), a mover bracket (8), a fixed base (9), a linear guide rail (10), a grating (11), a water cooling pipe (12), a micro-motion coil skeleton (13), a linear rolling bearing (14), a sliding rod (15), a yoke 2 (16), a magnetic isolation sleeve (17), a macro-motion coil (18), and a limiting groove (19), wherein the shell (1) is fixed to one side of the fixed base (9), the permanent magnet (2) is embedded in the inner side of the shell (1) to form a stator part, and the yoke 1 (3) is fixed to the mover bracket (8) by means of a fastening screw (4). The macro-motion coil (18) is wrapped with a water-cooling tube (12) and is placed in the interlayer between the yoke 1 (3) and one end of the permanent magnet (2). The GMM rod (6), the micro-motion coil frame (13), the micro-motion coil (5), and the yoke 2 (16) are wrapped in sequence from the inside to the outside of the yoke 1 (3) to form a micro-motion structure. The micro-motion structure is embedded and installed in the central part, and together with the magnetic isolation sleeve (17), the yoke 1 (3), and the macro-motion coil (18) form a mover part. The output rod (7) and the sliding rod (15) are located on both sides of the axis. The mover bracket (8) is installed on the fixed base (9) through a linear guide rail (10), and the stroke is limited by a limit groove (19). A grating (11) is installed on the same side of the mover bracket (8) and the fixed base (9) to measure the displacement. The controller will set a threshold of 30μm. After inputting the displacement information, the controller will start the macro-micro judgment. When the input value is less than the threshold, the micro-motion part will be started to move, and the micro-motion grating ruler will provide real-time position feedback to form a closed-loop control movement. When the input value is greater than the threshold, the controller will control the movement of the macro-motion part according to a predetermined control algorithm, and the macro-motion grating ruler will provide real-time position feedback. The controller will calculate the difference between the feedback value and the input value, and compare it with the threshold. If it reaches the range that the micro-motion system can compensate, the micro-motion system will be started to compensate until the target position is achieved.

[0008] Preferably, the present invention provides a macro-micro linear actuator based on GMM, in which a macro-dynamic coil (18) is energized in a stable magnetic field provided by a NdFeB N38H tile-shaped permanent magnet (2), and the generated Lorentz force pushes the mover part to move axially to obtain a macro-dynamic displacement, wherein the size of the Lorentz force is proportional to the size of the current in the conductive material, and the macro-displacement positioning is adjusted by controlling the current.

[0009] Preferably, the present invention provides a macro-micro linear actuator based on GMM. After the initial positioning of the macro motion system is completed, the macro motion system is in a stationary state. The micro motion system performs compensation control according to the detected system error to achieve secondary positioning. When current is passed through the micro motion coil (5), a stable strong magnetic field is generated around the GMM rod (6). Under the action of the strong magnetic field, the GMM rod (6) will stretch axially to obtain a micro displacement, which can compensate for the positioning accuracy of the macro motion, thereby achieving precise positioning of the entire motion. Preferably, the present invention provides a macro-micro linear actuator based on GMM. The temperature control adopts a water cooling temperature control method. The yoke 1 (3) serves as a skeleton. A layer of copper tube with a diameter of 5 mm is wound on the outside for water cooling to take away the heat generated by the coil. When installed in the actuator, it will not affect the magnetic circuit due to magnetic conduction. The copper tube is wound in a double helix cross-winding manner. While ensuring the tight winding, the water convection heat transfer efficiency will also be improved.

[0010] Preferably, the present invention provides a macro-micro linear actuator based on GMM, which uses a double "L"-shaped bracket as a support, and the mover bracket (8) is connected to the mover structure of the actuator. After the coil is energized with current, it performs linear motion along the X direction; a stator bracket boss is provided on one side of the fixed base (9), and a linear rolling bearing is installed in the upper slide rod limit hole to reduce the friction of linear motion; the two brackets are stacked and placed, and a linear guide rail (10) and a limit groove (19) are installed in the middle to further increase the smoothness of motion.

[0011] Compared with the prior art, the macro-micro linear actuator based on GMM provided by the present invention has the following beneficial effects:

[0012] The macro-motion system can realize fast and efficient positioning through the grating (11), thereby increasing the drive stroke, and the micro-motion system can realize precise feeding and error compensation, thereby utilizing the micro-motion with small stroke and high precision to compensate the motion error of the macro-motion with large stroke and coarse precision, and finally realizing the macro-micro composite motion with large stroke and high precision; because the macro-micro linear drive adopts the double "L"-shaped bracket as support, the structure is more compact, the positioning is more accurate, and the performance is more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the structural assembly of a macro-micro linear actuator based on GMM of the present invention;

[0014] In the figure, 1-housing, 2-permanent magnet, 3-yoke 1, 4-fastening screw, 5-micro-motion coil, 6-GMM rod, 7-output rod, 8-mover bracket, 9-fixed base, 10-linear guide, 11-grating, 12-water cooling pipe, 13-micro-motion coil skeleton, 14-linear rolling bearing, 15-sliding rod, 16-yoke 2, 17-magnetic isolation sleeve, 18-macro-motion coil, 19-limiting groove. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] In the description of the present invention, it is necessary to understand that the terms "setting", "inside", "end", "inside", etc., which indicate orientation or positional relationship, are only for the convenience of describing the present embodiment and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0017] See attached Figure 1As shown, this embodiment provides a macro-micro linear actuator based on GMM, comprising a housing (1), a permanent magnet (2), a yoke 1 (3), a fastening screw (4), a micro-motion coil (5), a GMM rod (6), an output rod (7), a mover bracket (8), a fixed base (9), a linear guide rail (10), a grating (11), a water-cooling pipe (12), a micro-motion coil skeleton (13), a linear rolling bearing (14), a sliding rod (15), a yoke 2 (16), a magnetic isolation sleeve (17), a macro-motion coil (18), and a limiting groove (19), wherein the housing (1) is fixed to one side of the fixed base (9), the permanent magnet (2) is embedded in the inner side of the housing (1) to form a stator part, and the yoke 1 (3) is fixed to the mover bracket (8) by a fastening screw (4). 8), a macro-motion coil (18) wrapped with a water-cooling tube (12) is placed in the interlayer between a yoke 1 (3) and one end of a permanent magnet (2), a GMM rod (6), a micro-motion coil frame (13), a micro-motion coil (5), and a yoke 2 (16) are sequentially wrapped inside the yoke 1 (3) from the inside to the outside to form a micro-motion structure, the micro-motion structure is embedded and installed in the central part, and together with a magnetic isolation sleeve (17), a yoke 1 (3), and a macro-motion coil (18) form a mover part, an output rod (7) and a sliding rod (15) are located on both sides of the axis, a mover bracket (8) is installed on a fixed base (9) through a linear guide rail (10), and a travel is limited by a limit groove (19), and a grating (11) is installed on the same side of the mover bracket (8) and the fixed base (9) to measure displacement. The controller will set a threshold. When the displacement information is input, the controller will start the macro-micro judgment. When the input value is less than the threshold, the micro-motion part will start to move, and the micro-motion grating ruler will provide real-time position feedback to form a closed-loop control movement. When the input value is greater than the threshold, the controller will control the movement of the macro-motion part according to a predetermined control algorithm, and the macro-motion grating ruler will provide real-time position feedback. The controller will calculate the difference between the feedback value and the input value, and compare it with the threshold. If it reaches the range that the micro-motion system can compensate, the micro-motion system will be started to compensate until the target position is achieved.

[0018] As a preferred embodiment of the present invention, the present invention provides a macro-micro linear actuator based on GMM, wherein the macro-moving coil is energized to generate a Lorentz force, which causes the mover part to move axially in the stable magnetic field provided by the NdFeB N38H tile-shaped permanent magnet, thereby obtaining a macro-moving displacement, wherein the size of the Lorentz force is proportional to the size of the current in the conductive material, and the macro-displacement positioning is adjusted by controlling the current;

[0019] As a preferred embodiment of the present invention, the present invention provides a macro-micro linear actuator based on GMM. After the initial positioning of the macro motion system is completed, the macro motion system is in a stationary state, and the micro motion system performs compensation control according to the detected system error to achieve secondary positioning. When current is passed through the micro motion coil, a stable strong magnetic field is generated around the GMM rod. Under the action of the strong magnetic field, the GMM rod will stretch axially to obtain micro displacement, which can compensate for the positioning accuracy of the macro motion, thereby achieving precise positioning of the entire motion.

[0020] As a preferred embodiment of the present invention, the present invention provides a macro-micro linear actuator based on GMM, in which temperature control adopts a water-cooling temperature control method. The yoke 1 acts as a skeleton, and a layer of copper tube with a diameter of 5 mm is wound on the outside for water cooling to take away the heat generated by the coil. When installed in the driver, it will not affect the magnetic circuit due to magnetic conduction; the copper tube is wound in a double helix cross-winding manner, which will improve the water convection heat transfer efficiency while ensuring tight winding.

[0021] As a preferred embodiment of the present invention, a macro-micro linear actuator based on GMM is provided by the present invention, which uses a double "L"-shaped bracket as a support, and the mover bracket is connected to the mover structure of the driver. After the coil is energized with current, it moves linearly along the X direction; a stator bracket boss is provided on one side of the fixed base, and a linear rolling bearing is installed in the upper slide rod limit hole to reduce the friction of linear motion; the two brackets are stacked and placed, and a linear guide rail and a limit groove are installed in the middle to further increase the smoothness of motion.

[0022] A specific application process of this embodiment is:

[0023] To achieve an axial displacement of 15.34432 mm, the steps are:

[0024] (1) Turn on the water cooling device and release the set screws to allow the shaft to gain axial freedom;

[0025] (2) Enter the target value 15.34432mm on the control panel;

[0026] (3) The program autonomously identifies the difference between the current displacement and the target value, and compares it with the threshold value (30 μm). When the difference is greater than the threshold value, the macro-motion coil is activated and a current of about 1.5 A is passed (the specific value of the current is controlled by the program of the given algorithm). When the difference is less than the threshold value, the accuracy of the macro-motion coil can no longer meet the accuracy required for the remaining displacement, and the micro-motion coil is activated. The control program passes an appropriate current (the size is given by the algorithm in the program) to the micro-motion coil, and the micro-motion structure compensates for the remaining displacement until the displacement reaches 15.34423 mm.

[0027] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0028] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A macro-micro linear actuator based on GMM, comprising a housing (1), a permanent magnet (2), a yoke 1 (3), a fastening screw (4), a micro-motion coil (5), a GMM rod (6), an output rod (7), a mover bracket (8), a fixed base (9), a linear guide rail (10), a grating (11), a water cooling tube (12), a micro-motion coil skeleton (13), a linear rolling bearing (14), a sliding rod (15), a yoke 2 (16), a magnetic isolation sleeve (17), a macro-motion coil (18), The housing (1) is fixed on one side of the fixed base (9), the permanent magnet (2) is embedded in the inner side of the housing (1), and the stator part is formed. The yoke 1 (3) is fixed on the mover bracket (8) by means of a fastening screw (4). The macro-motion coil (18) is wrapped with a water cooling tube (12) and is placed in the sandwich between the yoke 1 (3) and one end of the permanent magnet (2). The GMM rod (6), the micro-motion coil frame (13), the micro-motion coil (5), the yoke 2 (16) are wrapped in the yoke 1 (3) from the inside to the outside. ) form a micro-motion structure, the micro-motion structure is embedded and installed in the central part, and together with the magnetic isolation sleeve (17), the magnetic yoke 1 (3), and the macro-motion coil (18) form a mover part, the output rod (7) and the slide rod (15) are located on both sides of the axis, the mover bracket (8) is installed on the fixed base (9) through a linear guide rail (10), and the stroke is limited by a limit groove (19), and a grating (11) is installed on the same side of the mover bracket (8) and the fixed base (9) to measure the displacement; the controller will set a threshold value (30 microns), and when the displacement information is input, the controller will start the macro-micro judgment, when the input value is less than the threshold, the micro-motion part is started to move, and the micro-motion grating ruler performs position feedback in real time to form a closed-loop control movement; when the input value is greater than the threshold, the controller controls the macro-motion part to move according to a predetermined control algorithm, and the macro-motion grating ruler feeds back the position information in real time, the controller calculates the difference between the feedback value and the input value, and compares it with the threshold value, if it reaches the range that the micro-motion system can compensate, the micro-motion system is started to compensate until the target position is achieved.

2. A GMM-based macro-micro linear actuator according to claim 1, Features: In the stable magnetic field provided by the NdFeB N38H tile-shaped permanent magnet (2), the macro-moving coil (18) is energized to generate a Lorentz force, which pushes the mover part to move axially to obtain a macro-moving displacement. The size of the Lorentz force is proportional to the size of the current in the conductive material, and the macro-displacement positioning is adjusted by controlling the current.

3. A macro-micro linear actuator based on GMM according to claim 1, Features: After the initial positioning of the macro-motion system is completed, the macro-motion system is in a stationary state, and the micro-motion system performs compensation control based on the detected system error to achieve secondary positioning. When current is passed through the micro-motion coil (5), a stable strong magnetic field is generated around the GMM rod (6). Under the action of the strong magnetic field, the GMM rod (6) will stretch axially to obtain a micro-displacement, which can compensate for the positioning accuracy of the macro-motion, thereby achieving precise positioning of the entire movement.

4. A macro-micro linear actuator based on GMM according to claim 1, Features: The temperature is controlled by water cooling. The yoke 1 (3) acts as a skeleton. A copper tube with a diameter of 5 mm is wound around the outside for water cooling to take away the heat generated by the coil. When installed in the driver, it will not affect the magnetic circuit due to magnetic conduction. The copper tube is wound in a double helix cross-winding manner. While ensuring the winding is tight, it will also improve the water convection heat transfer efficiency.

5. The GMM-based macro-micro linear actuator according to claim 1, Features: A double "L"-shaped bracket is used as a support, and a mover bracket (8) is connected to the mover structure of the driver. After the coil is energized with current, it performs linear motion along the X direction. A stator bracket boss is provided on one side of the fixed base (9), and a linear rolling bearing is installed in the upper slide rod limit hole to reduce linear motion friction. The two brackets are stacked and placed, and a linear guide rail (10) and a limit groove (19) are installed in the middle to further increase the stability of the motion.

Images