A kind of active force control polishing device based on damping self-adaption

Abstract

This invention discloses a damping-adaptive main power control polishing device, comprising a voice coil motor and a variable damping electromagnetic damper. One end of the variable damping electromagnetic damper is connected to the drive end of the voice coil motor via a connecting plate, and the other end is fitted with a mounting plate. The variable damping electromagnetic damper includes an outer shell and a movable cylinder. The outer shell is provided with a guide partition, and the movable cylinder contains an excitation coil assembly. An induction coil is provided on the guide partition. The movable cylinder is movably inserted into the outer shell, and the guide partition is movably inserted into the movable cylinder. The induction coil is surrounded by the excitation coil. This invention achieves effective control of vibration during the polishing process and precise polishing force through adaptive adjustment of the damping force.

Description

Technical Field

[0001] This invention relates to the field of robotics and automation technology, specifically to a damping-adaptive main power control polishing device. Background Technology

[0002] With the rapid development of modern industry, industrial robots are being used more and more widely in various fields, especially in areas with harsh working environments and where repetitive and heavy tasks are required. In some contact-based work environments, industrial robots are often required to have a certain degree of contact sensing and adjustment capabilities to complete tasks such as clamping, grinding, polishing, and assembly.

[0003] The focus during polishing is on force control precision rather than positioning precision. Therefore, accurately controlling the polishing abrasive force is key to improving quality during the polishing process.

[0004] Currently, some polishing controls use DC motors, which, while achieving compliant control of multiple degrees of freedom, suffer from complex overall structures and high operational difficulty. In 2017, Yu Xin-gu, Huang Ting, and others proposed a force / position control strategy for robotic polishing and designed a passive compliant polishing device, which has proven to be practical. In 2019, Xiao C et al. proposed a force control strategy based on PD and BP neural networks and designed an electromagnetically-based flexible polishing device. By decoupling the position and force control between the robot and the polishing device, they achieved good polishing force control during polishing operations. Also in 2019, Chen F et al. designed a new intelligent polishing device that integrates two novel eddy current dampers to improve system stability. By suppressing spindle vibration, it improves the accuracy of the polishing force, making it suitable for thin-walled polishing.

[0005] While robotic polishing currently offers the advantages of replacing manual polishing, it still has some shortcomings:

[0006] 1. Most robotic polishing systems still employ a passive, compliant control strategy, which cannot precisely control the polishing force, making it impossible to complete operations with high workpiece quality requirements.

[0007] 2. Although the active control of polishing force in a few robotic polishing systems involves adding a force sensor to the end of the robot, it often results in constant force polishing. It cannot dynamically adjust the polishing force in real time according to the surface condition of the workpiece material, which can easily lead to over-polishing or under-polishing. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a damping-adaptive main power control polishing device.

[0009] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0010] A damping-adaptive main power control polishing device includes a voice coil motor and a variable damping electromagnetic damper. One end of the variable damping electromagnetic damper is connected to the drive end of the voice coil motor through a connecting plate, and the other end of the variable damping electromagnetic damper is equipped with a mounting plate.

[0011] The variable damping electromagnetic damper includes an outer shell and a movable cylinder. The outer shell is provided with a guide partition, and the movable cylinder is provided with an excitation coil assembly. The guide partition is provided with an induction coil. The movable cylinder is movably inserted into the outer shell, and the guide partition is movably inserted into the movable cylinder. The induction coil is surrounded by the excitation coil.

[0012] The guide partition is arranged along the central axis of the outer shell. Movable cavities are formed on both sides of the guide partition inside the outer shell. A central shaft hole is provided inside the movable cylinder. The guide partition extends into the central shaft hole, and both sides of the central shaft hole of the movable cylinder extend into the movable cavity.

[0013] The excitation coil assembly includes an upper excitation coil and a lower excitation coil, which are arranged in a top-to-bottom order around the movable cylinder, with the upper and lower excitation coils spaced apart.

[0014] A magnetic rod is installed inside the movable cylinder, and the magnetic rod is movably inserted into the guide partition.

[0015] The outer shell is made of a magnetically conductive material.

[0016] The voice coil motor selected is an Jacobs AVM80-12-C8-0.5 voice coil motor with a central bore.

[0017] The movable cylinder is equipped with a cap, which has a connecting end and an installation hole. The connecting end is connected to the connecting plate.

[0018] The outer casing is provided with a perforated mounting end, which is connected to the mounting plate.

[0019] The movable cylinder is provided with an upper groove and a lower groove. The upper excitation coil is spirally installed in the upper groove with several turns, and the lower excitation coil is spirally installed in the lower groove with several turns.

[0020] Compared with the prior art, the present invention has the following beneficial technical effects:

[0021] Using a voice coil motor as the primary power output device, the force and current have a linear relationship. The output force can be adjusted according to the workpiece's surface condition and material properties. Using a variable-damping electromagnetic damper as the adaptive damping device, the output force and current also have a linear relationship, and the force direction opposes the motion. As an active damping mechanism, it can adapt to different voice coil motor output forces and workpiece conditions. The variable-damping electromagnetic damper utilizes the Ampere force principle; the generated Ampere force always opposes motion. As an active damping mechanism, it can adapt to different voice coil motor output forces and workpiece conditions.

[0022] During assembly, it is connected to the main shaft of the polishing device. The main shaft passes through the voice coil motor, which provides the working power to ensure high-precision polishing of the workpiece surface quality and improve the polishing quality. Attached Figure Description

[0023] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0024] Figure 2 This is a three-dimensional structural diagram of the variable damping electromagnetic damper of the present invention;

[0025] Figure 3 This is a schematic cross-sectional view of the variable damping electromagnetic damper in this invention.

[0026] Figure 4 This is a schematic diagram illustrating the connection principle of the excitation coil assembly in this invention;

[0027] Figure 5 This is a schematic diagram illustrating the electromagnetic force principle of the present invention;

[0028] Figure label:

[0029] 1. Voice coil motor; 2. Variable damping electromagnetic damper; 3. Connecting plate; 4. Mounting plate; 5. Outer shell; 6. Movable cylinder; 7. Guide partition; 8. Induction coil; 9. Upper excitation coil; 10. Lower excitation coil; 11. Magnetic rod; 12. Cap; 13. Movable cavity; 14. Connecting end; 15. Mounting end. Detailed Implementation

[0030] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0031] In the description of this invention, it should be understood that if terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can refer to a mechanical connection or an electrical connection. They can refer to a direct connection or an indirect connection through an intermediate medium, and they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0033] Example 1

[0034] like Figure 1 and 2 As shown, a damping-adaptive active power control polishing device includes a voice coil motor 1 and a variable damping electromagnetic damper 2. One end of the variable damping electromagnetic damper 2 is connected to the drive end of the voice coil motor 1 via a connecting plate 3, and the other end of the variable damping electromagnetic damper 2 is fitted with a mounting plate 4. The voice coil motor is used as the active power output device, where the force and current have a linear relationship, allowing the current output to be adjusted according to the surface condition and material properties of the workpiece. The variable damping electromagnetic damper is used as the damping-adaptive device, where the output force and current also have a linear relationship, and the direction of the force opposes the direction of motion. As an active damping mechanism, it can achieve damping adaptation based on different output forces of the voice coil motor and different workpiece conditions.

[0035] A voice coil motor has a coil and a stator. The coil is the mover and moves within the stator. When current flows through the coil, it generates an Ampere force. The coil is subjected to this Ampere force to achieve feed motion. The magnitude of the force in this feed motion is only related to the current and is not affected by other factors. At the same time, the magnitude of the force in the feed motion is linearly related to the magnitude of the current. Therefore, a voice coil motor can be used for more precise control.

[0036] The voice coil motor selected is an Jacobs AVM80-12-C8-0.5 voice coil motor with a central bore. Since this polishing device is mounted at the end of the polishing spindle, and the polishing spindle passes through the polishing device, selecting a voice coil motor with a central bore facilitates the insertion of the polishing spindle into the voice coil motor for a secure connection.

[0037] Example 2

[0038] refer to Figure 1-5 As shown, the variable damping electromagnetic damper 2 includes an outer shell 5 and a movable cylinder 6. The outer shell 5 is provided with a guide partition 7, and the movable cylinder 6 contains an excitation coil assembly. An induction coil 8 is mounted on the guide partition 7. The movable cylinder 6 is movably inserted into the outer shell 5, and the guide partition 7 is movably inserted into the movable cylinder 6. The induction coil 8 is surrounded by the excitation coil assembly. When subjected to electromagnetic force, the movable cylinder 6 moves within the outer shell 5, extending and retracting to achieve control. A magnetic field is formed between the excitation coil assembly and the induction coil, ensuring the movement of the movable cylinder. The outer shell is cylindrical, and the guide partition 7 is arranged along the central axis of the outer shell 1. This guide partition 7 divides the interior of the outer shell 1 into two movable cavities 13 for the movable cylinder to move. For installation purposes, a central shaft hole is provided inside the movable cylinder, and the guide partition extends into the central shaft hole, using the guide partition as a directional movement track to achieve directional movement of the movable cylinder.

[0039] The excitation coil assembly includes an upper excitation coil 9 and a lower excitation coil 10, which are arranged in a top-to-bottom order around the movable cylinder, with the upper and lower excitation coils spaced apart. By setting two excitation coils, stability during movement is ensured, and sufficient electromagnetic force is generated.

[0040] A magnetic rod 11 is installed inside the movable cylinder 6. The magnetic rod 11 is movably inserted into the guide partition 7. The magnetic rod is made of magnetically conductive material, as is the outer shell. The movable insertion of the magnetic rod into the guide partition further ensures the stability of the movable cylinder's movement.

[0041] A cap 12 is installed on the movable cylinder 6. The cap 12 has a connecting end 14. The connecting end 14 has a mounting hole and is connected to the connecting plate 3. The outer shell 1 has a perforated mounting end 15, which is connected to the mounting plate 4.

[0042] The movable cylinder is provided with an upper groove and a lower groove. The upper excitation coil is spirally installed in the upper groove with several turns, and the lower excitation coil is spirally installed in the lower groove with several turns, to ensure the reliability of the assembly.

[0043] Example 3

[0044] refer to Figure 5 As shown, the electromagnetic force is the Ampere force. N and N represent the magnetic field poles. A closed coil, perpendicular to the plane of the paper, moves inward with a velocity v. R represents the coil's resistance. When a conductor cuts magnetic field lines, it generates an induced electromotive force, the direction of which can be determined using the right-hand rule.

[0045] The magnitude of the induced electromotive force can be calculated using the following formula:

[0046] E = BLV (1-1)

[0047] In the formula, B is the magnetic flux density in tons (T); v is the velocity perpendicular to the magnetic field lines in meters per second (m / s); L is the effective length of the coil cutting the magnetic field lines in meters (m); and the induced current I generated by the closed loop in a distance of amperes (A) can be expressed as:

[0048] In the formula: R is the coil resistance, in ohms.

[0049] A current-carrying conductor experiences an Ampere force in a magnetic field, which can be obtained from Ampere's law:

[0050] F = IBL (1-3)

[0051] Combining equations (1-1), (1-2), and (1-3), we can obtain:

[0052]

[0053] Ampere force is generated by the resistance of the coil to cut magnetic field lines. This can be determined according to the left-hand rule. Just as damping force always opposes motion, this characteristic of generating Ampere force can be used as a damping force in a damper.

[0054] In addition, when designing a variable damping electromagnetic damper, the magnetic field and current direction must be designed on the horizontal plane. When the coil moves vertically, it can generate its maximum Ampere force. However, the space of the damper is relatively small, and the magnetic field poles are difficult to obtain a strong magnetic field due to the limited space. In this case, the magnetic poles are vertically distributed so that the magnetic field of the part of the coil cutting the magnetic field lines is horizontal, thereby generating a controllable magnetic field.

[0055] refer to Figure 4As shown, let the magnetic induction intensity generated by the upper excitation coil and the lower upper excitation coil be B, and its damping force be expressed by formula (1-4). Here, the length L of the induction coil inside the outer shell is a constant, the resistance R of the induction coil is a constant, and only the magnetic induction intensity B is a controllable variable. Its calculation formula can be expressed by formula (1-4). The damping c can be calculated from formula (1-4):

[0056]

[0057] From formula (3-8), when B is a constant value, the damper is a passive suspension, which is a linear damper. Passive suspension means that the suspension system has no internal energy supply device, and the damping coefficient cannot be adjusted manually. This means that during grinding, the damping cannot be adjusted according to the contour of the workpiece. When B is a controllable variable, the damper is an active suspension. The damping coefficient of an active suspension can be adjusted in real time according to the workpiece condition. The change of B can be controlled by controlling the excitation current, thereby achieving the effect of controlling the damping. The relationship between B and the excitation current can be obtained using the following methods:

[0058] First, make the following settings: (1) Use a single-layer solenoid as a unit to set up the excitation coil; (2) Assume that the range of motion of the induction coil is all within the end of the excitation coil, so that the intensity of the magnetic field lines cut by the induction coil is considered to be the intensity at the end of the excitation coil; (3) The induction coil is inside the excitation coil, and the leakage magnetic field effect is not considered, so as to facilitate calculation.

[0059]

[0060] In the formula: n is the number of turns of the excitation coil; r is the radius of the excitation coil, in meters; i is the current of the excitation coil, in amperes (A); l is the length of the excitation coil, in meters; therefore:

[0061]

[0062] In the formula: r is the relative permeability of the magnetic material; 0 is the free permeability, with a value of 4π × 10⁻⁶. -7 NA -2 Combining equations (1-6) and (1-7), we can obtain

[0063]

[0064] It can be seen that the damping coefficient c has a square relationship with the excitation coil current i, and the damping coefficient can be controlled by changing the magnitude of the excitation current.

[0065] The continuous thrust is F = 34 N, the stroke is 12 mm (single stroke), and the coil mass is 124 g. From Newton's second law F = ma, we get:

[0066]

[0067] From the displacement acceleration formula have to:

[0068]

[0069] Therefore, the speed at which the voice coil motor outputs force is 2.5 m / s.

[0070] Based on the relationship between damping and current:

[0071]

[0072] Where r is taken

[0073] μ r μ0 represents the relative permeability of the magnetic material, with a value of 2000; μ0 represents the permeability of free space, with a value of 4π × 102. -7 NA -2 n is the number of turns of the excitation coil, with a value of 100; l is the length of the excitation coil, with a value of 5.

[0074] The unit is m; L—length of the induction coil, value 5, unit is m; i—current of the excitation coil, unit is A; r—radius of the excitation coil, value 0.025, unit is m; R—total resistance of the induction coil, value 5, unit is ohms; the relationship between damping force and damping is:

[0075] F = cv

[0076] Based on the above data and formulas, the following conclusions can be drawn:

[0077] F = 0.195i 2

[0078] When F = 10N, i = 7A

[0079] Based on the above calculation parameters, it can be seen that the variable damping electromagnetic damper is sufficient to achieve adaptive adjustment of force, and at the same time, the output force of the voice coil motor can smoothly achieve polishing.

[0080] It should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A damping-adaptive active power control polishing device, characterized in that, It includes a voice coil motor and a variable damping electromagnetic damper. One end of the variable damping electromagnetic damper is connected to the drive end of the voice coil motor through a connecting plate, and the other end of the variable damping electromagnetic damper is equipped with a mounting plate.

2. The active power control polishing device based on damping adaptive control according to claim 1, characterized in that, The variable damping electromagnetic damper includes an outer shell and a movable cylinder. The outer shell is provided with a guide partition, and the movable cylinder is provided with an excitation coil assembly. The guide partition is provided with an induction coil. The movable cylinder is movably inserted into the outer shell, and the guide partition is movably inserted into the movable cylinder. The induction coil is surrounded by the excitation coil.

3. The active power control polishing device based on damping adaptive control according to claim 2, characterized in that, The guide partition is arranged along the central axis of the outer shell. Movable cavities are formed on both sides of the guide partition inside the outer shell. A central shaft hole is provided inside the movable cylinder. The guide partition extends into the central shaft hole, and both sides of the central shaft hole of the movable cylinder extend into the movable cavity.

4. The active power control polishing device based on damping adaptive control according to claim 3, characterized in that, The excitation coil assembly includes an upper excitation coil and a lower excitation coil, which are arranged in a top-to-bottom order around the movable cylinder, with the upper and lower excitation coils spaced apart.

5. The active power control polishing device based on damping adaptive according to claim 4, characterized in that, A magnetic rod is installed inside the movable cylinder, and the magnetic rod is movably inserted into the guide partition.

6. The active power control polishing device based on damping adaptive control according to claim 5, characterized in that, The outer shell is made of a magnetically conductive material.

7. The active power control polishing device based on damping adaptive control according to claim 1, characterized in that, The voice coil motor selected is an Jacobs AVM80-12-C8-0.5 voice coil motor with a central bore.

8. The active power control polishing device based on damping adaptive control according to claim 2, characterized in that, The movable cylinder is equipped with a cap, which has a connecting end and an installation hole. The connecting end is connected to the connecting plate.

9. The active power control polishing device based on damping adaptive control according to claim 2, characterized in that, The outer casing is provided with a perforated mounting end, which is connected to the mounting plate.

10. The active power control polishing device based on damping adaptive according to claim 1, characterized in that, The movable cylinder is provided with an upper groove and a lower groove. The upper excitation coil is spirally installed in the upper groove with several turns, and the lower excitation coil is spirally installed in the lower groove with several turns.

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