A magnetic microrobot drive control device

Abstract

This invention discloses a magnetic microrobot drive control device, belonging to the field of microrobot drive control technology. It includes a multi-axis robot arm, a magnetic control platform base connected to the multi-axis robot arm, a magnetic ball holder connected to the magnetic control platform base, a magnetic ball cover covering the magnetic ball holder, and a permanent magnet ball rotatably disposed within the magnetic ball holder and magnetic ball cover. A coil base is disposed on the magnetic control platform base around the magnetic ball holder, and an electromagnetic coil unit is mounted on the coil base. This invention offers advantages such as a large working space, high precision control, and the ability to solve the problems of heat generation and dissipation during coil operation and limited working space. Finally, it boasts rapid response and low cost.

Description

Technical Field

[0001] This invention relates to a magnetic microrobot drive control device, belonging to the field of microrobot drive control technology. Background Technology

[0002] Magnetic microrobot drive and control platforms are generally divided into permanent magnet-based platforms and electromagnet-based platforms. Permanent magnet-based platforms cannot provide complex, diverse, and flexible controllable magnetic fields, while electromagnet-based platforms, due to space constraints and limited cooling systems, cannot generate strong magnetic fields, making it difficult to drive magnetic robots larger than millimeters. Existing magnetic control systems drive robots in three main ways: 1. Direct drive using permanent magnet spheres: A drive device or robotic arm directly manipulates a permanent magnet or magnetic field to rotate or translate it, thereby generating a controllable gradient magnetic field in space, thus controlling the robot's movement. 2. Electromagnetic field drive using coils: By passing a certain current through a Helmholtz coil or Maxwell coil, a constant or changing magnetic field is applied externally, adjusting the relative position of magnetic components or the direction of the magnetic field, thereby controlling the robot's movement. This method is commonly used in microrobots and drug delivery systems. 3. MRI (Magnetic Resonance Imaging) drive: This utilizes the magnetic field and gradient magnetic field of an MRI system to control and position objects (usually medical specimens or medical instruments). This technology is often used in medical applications, especially in minimally invasive surgery, drug delivery, and lesion localization.

[0003] Currently, the three methods mentioned above are widely used to drive magnetically controlled robots. While they do offer certain conveniences, they also have some drawbacks: 1. The main problems with driving permanent magnets using robotic arms lie in the limitations on their flexibility and precision. The flexibility limitation stems from the fact that the robotic arm's range of motion is restricted by its structure and design. In some narrow or complex environments, the robotic arm may struggle to manipulate permanent magnets flexibly, limiting its application. The lack of precision arises because direct control by the robotic arm means that the generation of the magnetic field depends entirely on the control precision of the robotic arm, requiring advanced control technology, which is difficult to achieve when precise control is needed for micro-robots. 2. The main problems with driving electromagnetic fields using coils lie in the limitations of coil heat dissipation and workspace. Regarding heat dissipation, electromagnetic coils generate heat during operation, which may adversely affect sensitive applications or applications requiring low-temperature environments. The heat can also lead to system overheating, causing malfunctions or reduced accuracy, thus requiring additional cooling measures. Regarding workspace, most mainstream electromagnetic coils currently use nested Helmholtz coils along the x, y, and z axes to generate magnetic fields in various directions. However, this nesting significantly reduces the available workspace, limiting the size and application scenarios of the magnetic robot. 3. The main problems with MRI-driven systems are system response speed and cost. In terms of response speed, since MRI systems are not designed for real-time motion control, MRI images are typically acquired at a relatively slow rate, resulting in a relatively slow response speed in real-time applications. Regarding cost, MRI-driven equipment and systems are generally expensive, making the purchase and maintenance costs prohibitively high for ordinary scientific research use. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a magnetic microrobot drive control device. First, it has a large working space and high precision control. Second, it can solve the problems of heat generation and heat dissipation during coil operation and limited working space. Finally, it has the advantages of fast response and low cost.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A magnetic microrobot drive control device includes a multi-axis robot arm, a magnetic control platform base connected to the multi-axis robot arm, a magnetic ball holder connected to the magnetic control platform base, a magnetic ball cover covering the magnetic ball holder, a permanent magnet ball rotatably disposed inside the magnetic ball holder and the magnetic ball cover, and a coil base disposed around the magnetic ball holder on the magnetic control platform base, with an electromagnetic coil unit installed on the coil base.

[0007] The magnetic ball cover includes a ball cover body, with a first groove formed on the inner edge of the ball cover body and a second groove formed on the top of the ball cover body. The magnetic ball holder includes a ball holder body, with a third groove formed on the inner edge of the ball holder body and a fourth groove formed on the bottom of the ball holder body. Copper balls are placed in the first, second, third, and fourth grooves.

[0008] The lower outer edge of the main body of the ball cover is provided with a first connecting protrusion, and a first opening is provided on the first connecting protrusion. The upper outer edge of the main body of the ball support is provided with a second connecting protrusion, and a second opening is provided on the second connecting protrusion. The bolt a passes through the first opening and the second opening and is fixed by the nut a.

[0009] Lubricating oil is applied to the first, second, third, and fourth grooves.

[0010] The number of coil bases and coils is N, where N is an integer greater than or equal to N.

[0011] The coil base is triangular, and a first mounting hole is provided on one right-angled surface of the coil base. The magnetic control platform base includes a second mounting hole on the platform body. The bolt b passes through the first mounting hole and the second mounting hole and is fixed by the nut b.

[0012] The electromagnetic coil unit includes a coil turn, around which a coil is wound. A coil ring is provided at the upper part of the coil turn, and a mounting protrusion is provided at the bottom of the coil turn. A central hole is provided at the beginning of the inclined surface of the coil base. The mounting protrusion extends into the central hole and is fixed by hot melt adhesive.

[0013] The coil is filled with thermally conductive silicone grease between each two layers.

[0014] The platform body has a support section at its lower part, and the support section is fixedly connected to the multi-axis robot arm.

[0015] The multi-axis robot arm is a six-axis robot arm.

[0016] The beneficial effects of this invention are as follows: This invention provides a magnetic microrobot drive and control device, based on a robotic arm combined with an electromagnetic spherical joint, which integrates a large workspace and precise control, effectively combining the advantages of electromagnetic and permanent magnet technologies. Compared to driving a permanent magnet through a robotic arm, the design of the robotic arm combined with the electromagnetic spherical joint gives the overall control system nine degrees of freedom, enabling obstacle avoidance and increased workspace through self-motion. The end effector electromagnetic spherical joint can further precisely control the magnetic robot based on the movement of the robotic arm itself. Compared to driving with an electromagnetic field generated by a coil, it avoids the heat generation and dissipation problems during operation. The semi-open design, combined with the large range of movement of the robotic arm, avoids the limitations of the coil frame, significantly increasing the workspace. Compared to MRI drive, the direct drive of the permanent magnet sphere allows for rapid changes in the magnetic field and a fast response. At the same time, the cost and maintenance costs are significantly reduced compared to MRI systems, making it suitable for more working scenarios. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a magnetic microrobot drive control device according to the present invention;

[0018] Figure 2 This is a schematic diagram of the electromagnetic ball joint portion in this invention;

[0019] Figure 3 yes Figure 2 A schematic diagram of the decomposed structure;

[0020] Figure 4 This is a schematic diagram of the magnetic ball cover in this invention;

[0021] Figure 5 This is a schematic diagram of the permanent magnet ball in this invention;

[0022] Figure 6 This is a schematic diagram of the magnetic ball holder in this invention;

[0023] Figure 7 This is a front structural diagram of the magnetic control platform base in this invention;

[0024] Figure 8 This is a schematic diagram of the lower structure of the magnetic control platform base in this invention;

[0025] Figure 9 This is a schematic diagram of the coil base in this invention;

[0026] Figure 10 yes Figure 9 A structural diagram from another perspective;

[0027] Figure 11 This is a schematic diagram of the electromagnetic coil unit in this invention;

[0028] Figure 12 This is a schematic diagram of the working principle of the magnetic microrobot drive control device of the present invention;

[0029] Figure 13 This is a process diagram of driving and controlling the magnetic robot according to the present invention.

[0030] The reference numerals in the figure are as follows: 1-Six-axis robot arm; 2-Magnetic control platform base; 3-Coil base; 4-Electromagnetic coil unit; 5-Magnetic ball cover; 6-Magnetic ball holder; 7-Permanent magnet ball; 21-Platform main body; 22-Second mounting hole; 23-Support part; 31-First mounting hole; Center hole; 41-Coil turn; 42-Coil ring; 43-Coil; 51-Ball cover main body; 52-First connecting protrusion; 53-First opening; 54-First groove; 55-Second groove; 61-Ball holder main body; 62-Second connecting protrusion; 63-Second opening; 64-Third groove; 65-Fourth groove. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present invention more clearly, and should not be used to limit the scope of protection of the present invention.

[0032] Example 1

[0033] like Figures 1 to 3 As shown, this invention discloses a magnetic microrobot drive control device. The first part is the assembly of the overall control system, the second part is the assembly of electromagnetic coils, and the third part is a multi-axis robot arm. The control system consists of a magnetic ball cover 5, a permanent magnet ball 7, a magnetic ball holder 6, four coil bases 3, and a magnetic control platform base 2. The magnetic ball holder 6 is connected to the magnetic control platform base 2, and the magnetic ball holder 6 is covered by the magnetic ball cover 5. The permanent magnet ball 7 is rotatably arranged inside the magnetic ball holder 6 and the magnetic ball cover 5. The coil bases 3 are arranged around the magnetic ball holder 6 on the magnetic control platform base 2. The electromagnetic coil consists of a solenoid and an electromagnetic coil unit 4, which are installed on the coil base 3. The multi-axis robot arm 1 is a six-axis robot arm, thereby realizing six degrees of freedom control of the magnetic control platform. The multi-axis robot arm 1 is connected to the magnetic control platform base 2.

[0034] like Figure 12As shown, the working principle of this invention is as follows: The magnetic microrobot drive control device can control a six-axis robotic arm to a general working range, and then apply specific voltage signals to four electromagnets to excite them to generate magnetic fields in arbitrary directions. This magnetic field, as the background magnetic field of the permanent magnet, can drive the spherical permanent magnet to rotate accordingly, thus generating the required magnetic field in a specific direction, as shown in the figure below. The magnitude and direction of the magnetic field can be adjusted in real time according to the current in the electromagnets, and the overall working range can also be changed by altering the position of the robotic arm's end effector during operation, achieving precise control over a wide range.

[0035] This invention, based on robotic arm control, combines the three degrees of freedom of an electromagnetic spherical joint for magnetic fields, achieving a total of nine degrees of freedom control. By utilizing the six degrees of freedom rotation of the robotic arm, a larger workspace is achieved, providing a more extensive and flexible solution for applications. In clinical applications, multiple parts of the human body can be magnetically controlled, solving the problems of limited control range and inflexible control systems in traditional magnetic control platforms. The redundant degrees of freedom combined with the robotic arm and electromagnetic spherical joint control system can greatly avoid the obstruction of obstacles in the control process, enabling the system to perform various complex tasks in more complex three-dimensional spaces, including more complex path planning and target positioning. Having more degrees of freedom means the system can perform movements in a more subtle and precise manner, which is crucial for applications requiring high precision, such as microsurgery. The electromagnetic-driven permanent magnet design solves the problems of inflexibility in traditional permanent magnet control and small workspace and weak magnetic fields in traditional electromagnetic control, while combining the advantages of fast response speed, strong magnetic field, and high flexibility of both traditional permanent magnet and electromagnetic control.

[0036] Example 2

[0037] like Figures 1 to 3 As shown, this invention discloses a magnetic microrobot drive control device. The first part is the assembly of the overall control system, the second part is the assembly of electromagnetic coils, and the third part is a multi-axis robot arm. The control system consists of a magnetic ball cover 5, a permanent magnet ball 7, a magnetic ball holder 6, four coil bases 3, and a magnetic control platform base 2. The magnetic ball holder 6 is connected to the magnetic control platform base 2, and the magnetic ball holder 6 is covered by the magnetic ball cover 5. The permanent magnet ball 7 is rotatably arranged inside the magnetic ball holder 6 and the magnetic ball cover 5. The coil bases 3 are arranged around the magnetic ball holder 6 on the magnetic control platform base 2. The electromagnetic coil consists of a solenoid and an electromagnetic coil unit 4, which are installed on the coil base 3. The multi-axis robot arm 1 is a six-axis robot arm, thereby realizing six degrees of freedom control of the magnetic control platform. The multi-axis robot arm 1 is connected to the magnetic control platform base 2.

[0038] The number of coil bases 3 and coils 4 is N, where N is an integer greater than or equal to 3. 3. For the steering control of the magnetic ball, theoretically, only three magnetic coils are needed to generate three magnetic degrees of freedom to achieve complete omnidirectional orientation control. Therefore, control systems with more than three electromagnetic coils can achieve the main functions of the system. In this embodiment, the preferred number of coil bases 3 and coils 4 is 4.

[0039] like Figure 4 As shown, the magnetic ball cover 5 includes a ball cover body 51, with a first groove 54 formed around the inner edge of the ball cover body 51, and a second groove 55 formed around the top of the ball cover body 51. Figure 6 As shown, the magnetic ball holder 6 includes a ball holder body 61. A third groove 64 is formed around the inner edge of the ball holder body 61, and a fourth groove 65 is formed around the bottom of the ball holder body 61. Copper balls are placed in the first groove 54, the second groove 55, the third groove 64, and the fourth groove 65. By placing copper balls in the grooves, this invention reduces the friction generated when the permanent magnet ball 7 rotates inside. This allows the permanent magnet ball 7 to rotate through the rolling friction of the copper balls, thus reducing direct friction and increasing control precision. The structure of the permanent magnet ball 7 is as follows... Figure 5 As shown. Furthermore, this invention applies lubricating oil to the first groove 54, second groove 55, third groove 64, and fourth groove 65. Through the interaction of the small copper balls and the lubricating oil, lubrication is achieved during the rotation of the permanent magnet ball 7. This invention, by designing a magnetic ball cover with copper balls, aims to enable the electromagnetic spherical joint to be inverted in space by offsetting friction. This innovative design, when combined with a robotic arm, allows the system to achieve a wider working space. This improvement not only expands the working range of the robotic arm but also increases its flexibility and applicability in various application scenarios.

[0040] A first connecting protrusion 52 is provided on the lower outer edge of the main body 51 of the ball cover, and a first opening 53 is provided on the first connecting protrusion 52. A second connecting protrusion 62 is provided on the upper outer edge of the main body 61 of the ball support, and a second opening 63 is provided on the second connecting protrusion 62. After the bolt a passes through the first opening 53 and the second opening 63, it is fixed by the nut a, so as to realize the assembly of the magnetic ball cover 5 and the magnetic ball support 6. The bolt a and the nut a are made by 3D printing. The first opening 53 and the second opening 63 are through holes with a diameter of 6mm.

[0041] like Figure 9 and Figure 10 As shown, the coil base 3 is triangular, and a first mounting hole 31 is formed on one right-angled surface of the coil base 3. Figure 7As shown, the magnetic control platform base 2 includes a platform body 21 with a second mounting hole 22. A bolt b passes through the first mounting hole 31 and the second mounting hole 22 and is fixed by a nut b, thus mounting the coil base 3 on the magnetic control platform base 2. The first mounting hole 31 and the second mounting hole 22 are through holes with a diameter of 6mm. Figure 8 As shown, a support part 23 is provided at the lower part of the platform body 21, and the support part 23 is fixedly connected to the multi-axis robot arm 1.

[0042] like Figure 11 As shown, the electromagnetic coil unit 4 includes a coil turn 41, around which a coil 43 is wound using a winder. The coil 43 is a common copper coil. A coil ring 42 is provided on the upper part of the coil turn 41 to prevent the coil 43 from falling off. A mounting protrusion 41 is provided at the bottom of the coil turn 41. A central hole 32 is formed on the inclined surface of the coil base 3. The mounting protrusion 41 extends into the central hole 32 and is fixed with hot melt adhesive. Thermal grease is filled between each layer of coil 43. A layer of thermal grease with a thermal conductivity of 5.0 is applied every 40-50 turns of 0.38mm diameter enameled wire. The thermal grease increases the thermal conductivity, allowing the heat generated by the inner enameled wire to be quickly transferred to the outer layer.

[0043] like Figure 13 As shown, the application of this invention to drive and control a magnetic robot specifically includes the following steps:

[0044] Step 1: System initialization, preparing the controlled object (magnetic robot) and the environment to be controlled.

[0045] Step 2: Turn on the top camera and move its position to adjust the imaging field of view. Use the camera to initially locate the position of the magnetic robot, select the experimental environment of interest, and control the six-axis robotic arm to move until the end of the arm reaches the appropriate control position.

[0046] Step 3: Connect the four coils to the output terminal of the power amplifier module, connect the signal output terminal of the DAQ board to the input terminal of the power amplifier module, and turn on the power.

[0047] Step 4: Open the host computer control software of this system, start the program and connect the handle.

[0048] Step 5: Adjust the maximum value of the output signal to prevent the coil from burning out due to excessive current, and start the signal output function of the host computer.

[0049] Step six: Based on the position of the microscale magnetic droplet robot in the field of view, adjust the state of the joystick in the handle so that the host computer generates four specific voltage signals. These voltage signals are amplified by a power amplifier and then connected to four electromagnets, so that they generate a dynamic magnetic field rotating in a specific direction in space under their mutual cooperation. This, in turn, drives the spherical magnet to rotate, generating a spatial magnetic field with a larger range and intensity.

[0050] Step seven: Under the influence of the magnetic field generated by the movement of the permanent magnet, the magnetic robot also rotates.

[0051] Step 8: Continuously adjust the output voltage signal through the handle to change the rotation direction of the spherical permanent magnet, thereby adjusting the rolling direction of the magnetic robot and realizing the control of its motion behavior and path tracking control.

[0052] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A magnetic micro-robot driving control device, characterized by: The system includes a multi-axis robot arm (1), a magnetic control platform base (2) connected to the multi-axis robot arm (1), a magnetic ball holder (6) connected to the magnetic control platform base (2), a magnetic ball cover (5) covering the magnetic ball holder (6), a permanent magnet ball (7) rotatably disposed inside the magnetic ball holder (6) and the magnetic ball cover (5), a coil base (3) disposed around the magnetic ball holder (6) on the magnetic control platform base (2), an electromagnetic coil unit (4) installed on the coil base (3), the magnetic ball cover (5) including a ball cover body (51), a first groove (54) formed on the inner edge of the ball cover body (51), a second groove (55) formed on the top of the ball cover body (51), the magnetic ball holder (6) including a ball holder body (61), a third groove (64) formed on the inner edge of the ball holder body (61), and a fourth groove (65) formed on the bottom of the ball holder body (61). 65), copper balls are placed in the first groove (54), the second groove (55), the third groove (64) and the fourth groove (65). The coil base (3) is triangular. A first mounting hole (31) is opened on a right-angled surface of the coil base (3). The magnetic control platform base (2) includes a platform body (21). A second mounting hole (22) is opened on the platform body (21). The bolt b passes through the first mounting hole (31) and the second mounting hole (22) and is fixed by the nut b. The electromagnetic coil unit (4) includes a coil turn (41). A coil (43) is wrapped around the coil turn (41). A coil ring (42) is provided on the upper part of the coil turn (41). An installation protrusion is provided on the bottom of the coil turn (41). A central hole (32) is opened on the inclined surface of the coil base (3). The installation protrusion extends into the central hole (32) and is fixed by hot melt glue.

2. The magnetic micro-robot driving control device according to claim 1, wherein: The lower outer edge of the ball cover body (51) is provided with a first connecting protrusion (52), and a first opening (53) is provided on the first connecting protrusion (52). The upper outer edge of the ball support body (61) is provided with a second connecting protrusion (62), and a second opening (63) is provided on the second connecting protrusion (62). The bolt a passes through the first opening (53) and the second opening (63) and is fixed by the nut a. ​ 3. The magnetic micro-robot driving control device according to claim 1, characterized in that: Lubricating oil is applied to the first groove (54), the second groove (55), the third groove (64) and the fourth groove (65).

4. The magnetic micro-robot driving control device according to claim 1, characterized in that: The number of coil bases (3) and electromagnetic coil units (4) is N, where N is an integer greater than or equal to 3.

5. The magnetic micro-robot driving control device according to claim 1, characterized in that: The coil (43) is filled with thermally conductive silicone grease between each two layers.

6. The magnetic micro-robot driving control device according to claim 1, characterized in that: The platform body (21) has a support part (23) at its lower part, and the support part (23) is fixedly connected to the multi-axis robot arm (1).

7. The magnetic micro-robot driving control device according to claim 1, characterized by: The multi-axis robot arm (1) is a six-axis robot arm.

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