WO2023277237A1 - Three-dimensional electromagnetic actuation system - Google Patents

Abstract

The present invention relates to a three-dimensional electromagnetic actuation system and, more specifically, to a three-dimensional electromagnetic actuation system in which the same four circular coils are arranged in a tetrahedral shape to form a small number of three-dimensional coil structures, so that the control space of a microrobot can be reduced and the power efficiency thereof can be increased. The three-dimensional electromagnetic actuation system according to the present invention comprises: a coil unit (100) which is formed by arranging, in a tetrahedral shape, a first coil (110), a second coil (120), a third coil (130) and a fourth coil (140) that maintain predetermined angles therebetween on the X, Y, and Z axes, and which has a control space (working area) formed therein; and a microrobot provided in the control space so that the motion thereof is controlled by means of a magnetic field generated through the coil unit (100).

Description

Three-dimensional electromagnetic drive system

The present invention relates to a three-dimensional electromagnetic drive system, and more particularly, by arranging four identical circular coils in a tetrahedral shape to form a small number of three-dimensional coil structures, thereby reducing the control space of a microrobot and improving power efficiency. It relates to a three-dimensional electromagnetic drive system that can be increased.

In general, electromagnetic coils, unlike permanent magnets, which are difficult to control magnetic fields, can conveniently control the magnetic field generated inside by adjusting the current input to the coil, so they are widely used in various devices such as motors, generators, and electromagnetic actuators.

In particular, in the case of generating various mechanical movements of a device using a magnetic field, such as an electromagnetic actuator, a combination of a plurality of electromagnetic coils is required to generate various types of magnetic fields.

Meanwhile, in order to downsize or increase the efficiency of a device using an electromagnetic coil, it is required to develop an electromagnetic coil that is structurally and electromagnetically effective. Conventionally, different coils are used to generate various types of magnetic fields.

For example, a Helmholtz coil or uniform saddle coil can create an axially uniform magnetic field inside, and a Maxwell coil or gradient saddle coil inside An axial gradient magnetic field may be generated, and a Golay coil may generate a lateral gradient magnetic field therein.

In other words, a conventional electromagnetic coil can generate only one type of magnetic field with one coil, and accordingly, in a device requiring multiple types of magnetic fields, the number of electromagnetic coils must be increased by the type of magnetic field required. In this case, a problem in that the device becomes more complicated and the size becomes larger may occur.

In addition, considering that the strength of the magnetic field is inversely proportional to the radius of the electromagnetic coil, proportional to the strength of the current, and the power consumption of the electromagnetic coil is proportional to the radius of the electromagnetic coil, the above-mentioned problem is that the magnetic field generation efficiency of the device is also rapidly reduced. can drop

In order to solve this problem, there are cases where a structurally effective method has been developed to apply to various devices by developing a number of electromagnetic coils having a structure that can be mounted on a cylinder (cylinder), There is a limit to how many can be increased.

In addition, due to geometric problems caused by the structure of the coil, the range that can be controlled using the electromagnetic coil is reduced, and the state values of the coil, such as resistance, radius, and inductance, are different, so that each coil uses a different power supply. There was a hassle to do.

An example of a technique for solving this problem is disclosed in Document 1 below.

Korean Patent Registration No. 10-1450091 (registered on October 6, 2014) discloses an electromagnetic coil system for driving control of a microrobot, comprising: a pair of X-axis Helmholtz coils in which the winding central axis of the coil is placed on the X-axis; a pair of Y-axis Helmholtz coils in which the winding central axis of the coil is placed on the Y-axis; a position recognition system for detecting the position and direction of the microrobot on the workspace; A control unit for controlling the amount of current supplied to the X-axis Helmholtz coil or the Y-axis Helmholtz coil to control the movement of the micro-robot based on the micro-robot motion information obtained from the position recognition system and the input path information of the micro-robot; and a current amplifier supplying a corresponding current to each Helmholtz coil in response to a current control command from the control unit, wherein the pair of X-axis Helmholtz coils are disposed to face each other, and the pair of Y-axis Helmholtz coils face each other. The coils are disposed to face each other, and the X-axis Helmholtz coil and the Y-axis Helmholtz coil are vertically intersected to form a working space of the microrobot, and the control unit has the same size and direction as the rotation current and the same direction. An electromagnetic coil system characterized by performing direction change and movement control of a microrobot by applying a current value obtained by overlapping these opposite propulsion currents to a pair of X-axis Helmholtz coils or a pair of Y-axis Helmholtz coils, respectively. about is disclosed.

However, the conventional technology as described above has a problem in that an effective space for utilizing a magnetic field is relatively small due to a geometrical problem of the coil system.

The present invention has been made to solve the above problems, and by arranging the same four circular coils in a tetrahedral shape to form a small number of three-dimensional coil structures, thereby reducing the control space of the microrobot and improving power efficiency. It is an object to provide a three-dimensional electromagnetic drive system that can be increased.

In addition, an object of the present invention is to provide a three-dimensional electromagnetic drive system in which the control range of the microrobot is increased and the state value of the coil is the same, so that the microrobot can be easily controlled.

In addition, an object of the present invention is to provide a three-dimensional electromagnetic drive system having a symmetrical structure with respect to the center of the system.

In order to achieve the above object, in the three-dimensional electromagnetic drive system according to the present invention, in the three-dimensional electromagnetic drive system, the first coil 110 and the second coil 120 maintain a constant angle with each other on the X, Y, and Z axes. ), the third coil 130 and the fourth coil 140 are arranged in a tetrahedral shape, and a coil unit 100 having a working area formed therein; and a microrobot provided in the control space and whose movement is controlled by the magnetic field generated by the coil unit 100.

In addition, the first coil 110, the second coil 120, the third coil 130, and the fourth coil 140 are characterized in that each radius and the number of wound coils are the same.

In addition, the micro-robot is characterized in that a magnet is provided therein and driven by a magnetic field of the coil unit 100.

In addition, the three-dimensional electromagnetic drive system is characterized in that it includes a power supply for supplying a current value having the same current direction to the coil unit 100.

In addition, the power supply unit is connected to the control panel and simultaneously controls the current applied to the first coil 110, the second coil 120, the third coil 130 and the fourth coil 140. to be

In addition, the equation for controlling the three-dimensional movement of the microrobot,

It is characterized by being

As described above, the 3D electromagnetic drive system according to the present invention arranges four circular coils in a tetrahedral structure to form a 3D coil structure, thereby reducing the control space of the microrobot and increasing power efficiency.

In addition, the controllable range of the microrobot is increased, and since the state values of the coils are the same, it is easy to control the microrobot.

1 is a front view showing a three-dimensional electromagnetic drive system according to the present invention;

2 is a plan view showing a three-dimensional electromagnetic drive system according to the present invention;

3 is a view showing a driving state of a microrobot disposed in an external magnetic field.

4 is a plan view and a front view showing a coordinate system of a three-dimensional electromagnetic drive system according to the present invention.

5 is an exemplary view showing a coordinate system of a three-dimensional electromagnetic drive system according to the present invention;

Hereinafter, the most preferred embodiments of the present invention will be described in detail in order to explain the present invention in detail to the extent that those skilled in the art can easily practice the present invention.

As shown in FIGS. 1 to 5, the 3D electromagnetic driving system according to the present invention is for performing 3D position and direction control of a microrobot, and includes a coil unit 100 and a microrobot (not shown). do.

The coil unit 100 is a tetrahedron in which a first coil 110, a second coil 120, a third coil 130, and a fourth coil 140 maintain constant angles with each other on the X, Y, and Z axes. It is arranged and configured in shape.

The first coil 110, the second coil 120, the third coil 130, and the fourth coil 140 have the same shape as each other.

In particular, the second coil 120, the third coil 130, and the fourth coil 140 are arranged and configured in a tetrahedral shape, thereby having a symmetrical structure with respect to the center of the entire system.

A working area is formed inside the coil unit 100, and a microrobot is provided in the control space.

The first coil 110, the second coil 120, the third coil 130, and the fourth coil 140 have the same radius and the same number of wound coils.

As described above, the present invention can reduce the control space of the microrobot and increase power efficiency by arranging the same four circular coils in a tetrahedral shape to form a small number of three-dimensional coil structures.

The microrobot (not shown) is provided in the control space and its movement is controlled by a magnetic field generated by the coil unit 100 .

The microrobot has a magnet inside and is driven by the magnetic field of the coil unit 100 .

Meanwhile, the three-dimensional electromagnetic driving system of the present invention includes a power supply unit (not shown) that supplies current values having the same current direction to the coil unit 100 .

The power supply unit is connected to a control panel (not shown) to simultaneously control currents applied to the first coil 110, the second coil 120, the third coil 130, and the fourth coil 140. .

A 3-dimensional electromagnetic drive system (Quartet of Electromagnetic Coils, QEC) according to the present invention forms a 3-dimensional coil structure by arranging four circular coils in a tetrahedral structure, which can be expressed by the following equation.

The three-dimensional electromagnetic drive system (QEC) of the present invention has a form in which four identical circular coils are arranged in a tetrahedral structure. At this time, if the global coordinate system (X) is defined based on the center of gravity of the three-dimensional electromagnetic drive system and the local coordinate system (Xk) is defined based on the center of each coil, the coordinate conversion relationship between the global coordinate system and the local coordinate system of coil k is As follows.

here,

Wow

are based on the x and z axes of the global coordinate system, respectively.

Wow

It means the rotation matrix as much as .

Wow

Considering that is a regular tetrahedral structure, it is shown in Table 1 below.

Angle	1st coil	2nd coil	3rd coil	4th coil
	0°	250.53°	250.53°	250.53°
	0°	0°	0°	0°

On the other hand, the external magnetic field (

), the microrobot placed in the following magnetic torque (

) and magnetic force (

) is received.

here,

is the magnetic moment of the microrobot. The alignment motion of the microrobot converges to the equilibrium posture relatively quickly compared to the translational motion.

That is, it can be assumed that the magnetic moment of the microrobot is always parallel to the external magnetic field (

下

). Therefore, in order to control the alignment and translational motion of the microrobot, a desired three-dimensional magnetic field and magnetic force must be output. Assuming that the microrobot is placed on the center of gravity of the 3D electromagnetic driving system, the equation for controlling the 3D movement of the microrobot is as follows.

here,

,

denotes the desired magnetic field and the strength of the magnetic force. α and β mean the angle formed by the orthographic projection on the xy plane of the desired output with the x-axis, and the angle formed by the desired output with the z-axis, respectively.

Also,

The magnetic field generated by the burn coil at the periphery of the axis can be expressed by the following equation.

here,

are the number of turns and radius of the coil, the magnetic permeability of the vacuum, and the current applied to the coil, respectively. The magnetic field generated by the three-dimensional electromagnetic drive system is equal to the sum of the magnetic fields generated by each coil. The total magnetic field generated by the three-dimensional electromagnetic drive system (

) can be induced.

The gradient of the magnetic field distribution from Equation 6 is as follows.

Therefore, the magnetic field and magnetic force applied to the microrobot placed at the center of gravity by the three-dimensional electromagnetic drive system using Equations 6 and 7 are as follows.

here,

class

are respectively

class

to be. As can be seen from Equation 5, the distribution of the magnetic field generated by the coil is proportional to the applied current. Therefore, it can be seen from Equations 8 and 9 that the magnetic field and magnetic force generated by the 3D electromagnetic driving system have a linear relationship with the current applied to each coil.

Therefore, Equation 4 for controlling the three-dimensional motion of the microrobot can be expressed as a system of linear equations for the current applied to each coil.

Here, A, I, Y are the coefficient matrix of current and output, respectively, and the current matrix applied to the three-dimensional electromagnetic drive system (

), which means the desired output. As a result, if the current solution is obtained from Equation 10, the current required for each coil to control the movement and alignment of the microrobot can be calculated.

Although the present invention has been described with reference to the preferred embodiments with reference to the accompanying drawings, it is clear that various modifications are possible to those skilled in the art from this description without departing from the scope of the present invention. Accordingly, the scope of the present invention should be construed by the claims described to include examples of these many variations.

By arranging the same four circular coils according to the present invention in a tetrahedral shape to form a small number of three-dimensional coil structures, it can greatly contribute to reducing the control space of the microrobot and increasing power efficiency.

Claims (6)

1. In the three-dimensional electromagnetic drive system,

   The first coil 110, the second coil 120, the third coil 130, and the fourth coil 140 maintaining a constant angle with each other on the X, Y, and Z axes are arranged in a tetrahedral shape and configured, a coil unit 100 having a working area formed therein;

   A three-dimensional electromagnetic drive system comprising a; microrobot provided in the control space and whose movement is controlled by the magnetic field generated by the coil unit 100.
2. The method of claim 1,

   The first coil (110), the second coil (120), the third coil (130), and the fourth coil (140) have the same radius and the same number of wound coils as each other. .
3. The method of claim 1,

   The three-dimensional electromagnetic drive system, characterized in that the micro-robot is provided with a magnet inside and driven by the magnetic field of the coil unit (100).
4. The method of claim 1,

   The three-dimensional electromagnetic driving system comprises a power supply unit supplying a current value having the same current direction to the coil part (100).
5. The method of claim 4,

   The power supply unit is connected to the control panel to simultaneously control the current applied to the first coil 110, the second coil 120, the third coil 130 and the fourth coil 140 Three-dimensional electromagnetic drive system.
6. The method of claim 1,

   The equation for controlling the three-dimensional movement of the microrobot is,

   

   A three-dimensional electromagnetic drive system, characterized in that.

   (here,

   

   ,

   

   is the strength of the desired magnetic field and magnetic force, α and β are the angle formed by the orthographic projection on the xy plane of the desired output with the x-axis, and the angle formed by the desired output with the z-axis.)

Images