Magnetic motion platform and control method thereof

Abstract

This invention provides a magnetic motion platform and its control method, relating to the field of magnetic levitation technology. The control method only requires the projection area and the stator region of the target stator unit to determine the assigned weights of the target stator unit, and controls the target stator unit according to the preset driving force and assigned weights. This eliminates the need for finite element modeling of the electromagnetic field or large matrix operations, thus improving computational efficiency. The control can be completed within a 1ms control cycle, meeting the real-time control requirements at the 1kHz level. Furthermore, only the dimensions of the projection area and the stator region need to be determined to control the target stator unit, eliminating the need for extensive electromagnetic field calibration work for each mover assembly-stator unit combination, thus simplifying calibration and providing good scalability. Finally, the assigned weights of the target stator unit continuously change with the real-time position of the mover assembly, ensuring the smoothness of the mover assembly's motion and thereby improving the control accuracy of the magnetic motion platform.

Description

Technical Field

[0001] This invention relates to the field of magnetic levitation technology, and in particular to a magnetic motion platform and its control method. Background Technology

[0002] A magnetic motion platform, also known as a planar magnetic levitation motion platform, is an advanced motion control system that uses electromagnetic force to achieve six degrees of freedom (X, Y, Z, Rx, Ry, Rz) levitation and precise positioning of a mover in a two-dimensional plane. In practical applications, a magnetic motion platform typically consists of multiple stator units laid flat to form a planar working area. Each stator unit contains a three-phase planar coil, and a permanent magnet array is installed at the bottom of the mover. When the mover moves in the planar working area, its rectangular projection area may simultaneously cover one, two, or four stator units.

[0003] In existing magnetic motion platforms, for the force distribution problem when the mover crosses multiple stator units, the relevant technical solutions usually rely on accurate electromagnetic field finite element models or lookup table methods to determine the coupling relationship between the mover and each stator unit. However, there are the following shortcomings: ① Large computational load: Solving the finite element model requires a lot of computational resources, which is difficult to complete within a real-time control cycle of 1kHz; ② Complex calibration: The lookup table method requires a lot of electromagnetic field calibration work for each mover-stator unit combination, resulting in poor scalability and thus failing to meet the actual control requirements. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a magnetic motion platform and a control method thereof to alleviate the above-mentioned technical problems.

[0005] In a first aspect, embodiments of the present invention provide a control method for a magnetic motion platform. The magnetic motion platform includes a stator assembly, a mover assembly, and a position detection assembly. The stator assembly includes multiple stator units that form a planar working area. The mover assembly includes a power magnet, and each stator unit includes a drive coil. The mover assembly can move within the planar working area under the drive of the stator assembly. The position detection assembly is used to detect the real-time position of the mover assembly within the planar working area. The control method includes: acquiring the projection area of ​​the mover assembly on the planar working area when it moves; determining a target stator unit based on the overlap area between the projection area and the stator areas of each stator unit; wherein the target stator unit is a stator unit covered by the mover assembly; determining the coverage area ratio of the target stator unit based on the projection area and the stator area of ​​the target stator unit, and determining the allocation weight of the target stator unit based on the coverage area ratio; acquiring a preset driving force of the mover assembly; determining the allocation force of the target stator unit based on the preset driving force and the allocation weight; determining the driving current of the target stator based on the allocation force of the target stator unit, and controlling the target stator unit based on the driving current.

[0006] Optionally, the overlapping area includes the overlapping lengths in the X and Y directions; determining the target stator unit based on the overlapping area between the projection area and the stator area of ​​each stator unit includes: determining the overlapping lengths of the mover assembly and each stator unit in the X and Y directions respectively based on the projection area and the stator area of ​​each stator unit; and selecting stator units whose overlapping lengths in both the X and Y directions are greater than a preset threshold as target stator units.

[0007] Optionally, the coverage area ratio of the target stator unit is determined based on the projection area and the stator area of ​​the target stator unit, and the allocation weight of the target stator unit is determined based on the coverage area ratio, including: determining the overlap area between the mover assembly and the target stator unit based on the projection area and the stator area of ​​the target stator unit; determining the coverage area ratio of the target stator unit based on the overlap area and the area of ​​the projection area; and determining the allocation weight of the target stator unit based on the coverage area ratio.

[0008] Optionally, if there are multiple target stator units, the allocation weight of the target stator units is determined according to the coverage area ratio, including: normalizing the coverage area ratio of the multiple target stator units to obtain the allocation weights corresponding to the multiple target stator units respectively; wherein the sum of the allocation weights corresponding to the multiple target stator units is 1.

[0009] Optionally, determining the overlap area between the mover assembly and the target stator unit based on the projection area and the stator area of ​​the target stator unit includes: determining a first overlap length in the X direction and a second overlap length in the Y direction between the mover assembly and the target stator unit based on the projection area and the stator area of ​​the target stator unit; and determining the overlap area based on the first overlap length and the second overlap length.

[0010] Optionally, the preset driving force includes a preset driving force in the X direction and a preset driving force in the Y direction, and the distribution force includes a distribution force in the X direction and a distribution force in the Y direction; determining the distribution force of the target stator unit according to the preset driving force and the distribution weight includes: determining the distribution force of the target stator unit in the X direction according to the preset driving force and the distribution weight, and determining the distribution force of the target stator unit in the Y direction according to the preset driving force and the distribution weight.

[0011] Optionally, the preset driving force includes a preset rotational torque for rotating around the Z-axis, and the distribution force includes a distribution force in the X direction and a distribution force in the Y direction. Determining the distribution force of the target stator unit based on the preset driving force and the distribution weight includes: determining the distribution torque of the target stator unit based on the preset rotational torque and the distribution weight; and determining the distribution force of the target stator unit in the X direction and the distribution force in the Y direction based on the distribution torque, a first offset, and a second offset. The first offset is the offset of the center of the mover assembly relative to the center of the target stator unit in the X direction, and the second offset is the offset of the center of the mover assembly relative to the center of the target stator unit in the Y direction.

[0012] Optionally, the method further includes: when multiple moving parts simultaneously cover the same target stator unit, determining the driving current generated by the multiple moving parts on the target stator unit respectively; determining the total driving current based on the driving current of the multiple moving parts; and controlling the target stator unit based on the total driving current.

[0013] Secondly, embodiments of the present invention also provide a magnetic motion platform, comprising: a controller, a stator assembly, a mover assembly, and a position detection assembly; wherein the stator assembly includes multiple stator units forming a planar working area, the mover assembly includes a power magnet, the stator units include drive coils, the mover assembly can move within the planar working area under the drive of the stator assembly, the position detection assembly is used to detect the real-time position of the mover assembly within the planar working area; the controller is used to control the magnetic motion platform using the control method described in the first aspect.

[0014] Thirdly, embodiments of the present invention also provide a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the steps of the control method described in the first aspect.

[0015] The embodiments of the present invention bring the following beneficial effects: This invention provides a magnetic motion platform and its control method. The method involves acquiring the projection area of ​​the mover assembly on a planar working area during movement, determining a target stator unit based on the projection area and the stator areas of each stator unit, wherein the target stator unit is the stator unit covered by the mover assembly; determining the allocation weight of the target stator unit based on the projection area and the stator area of ​​the target stator unit; acquiring the preset driving force of the mover assembly, determining the allocation force of the target stator unit based on the preset driving force and the allocation weight; determining the driving current of the target stator based on the allocation force of the target stator unit, and controlling the target stator unit based on the driving current. The aforementioned control method, on the one hand, only requires the projection area of ​​the mover assembly on the planar working area and the stator region of the target stator unit to determine the weighting of the target stator unit. The distribution force is determined based on the preset driving force and the distribution weight, and the target stator unit is controlled according to the driving current corresponding to the distribution force. Compared with related technical solutions, it eliminates the need for finite element modeling of the electromagnetic field or large matrix operations, thus improving computational efficiency. It can be completed within a 1ms control cycle, meeting the real-time control requirements at the 1kHz level. On the other hand, it only requires determining the dimensions of the projection area and the stator region of the target stator unit to control the target stator unit, eliminating the need for extensive electromagnetic field calibration work for each mover assembly-stator unit combination. This simplifies calibration and provides good scalability. Furthermore, the projection area continuously changes with the real-time position of the mover assembly, causing a continuous change in the weighting of the target stator unit, resulting in a continuous change in the distribution force of the target stator unit. This avoids abrupt force changes at the boundary, ensuring the smoothness of the mover assembly's movement and thus improving the control accuracy of the magnetic motion platform.

[0016] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0017] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1A three-dimensional structural schematic diagram of a magnetic motion platform provided in an embodiment of the present invention; Figure 2 A flowchart illustrating a control method for a magnetic motion platform provided in an embodiment of the present invention; Figure 3 A schematic diagram of a moving part covering a stator unit provided in an embodiment of the present invention; Figure 4 A schematic diagram of a mover assembly covering two stator units provided in an embodiment of the present invention; Figure 5 A schematic diagram of a mover assembly covering four stator units provided in an embodiment of the present invention; Figure 6 This is a geometric schematic diagram of a projection area and a stator area provided in an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] To facilitate understanding of this embodiment, the embodiments of the present invention will be described in detail below.

[0022] This invention provides a control method for a magnetic motion platform; wherein, as shown in the embodiments of the present invention... Figure 1 As shown, the magnetic motion platform 100 includes a stator assembly 10, a mover assembly 20, and a position detection component 30. The stator assembly 10 includes multiple stator units 11, meaning the stator assembly 10 is composed of multiple stator units 11 joined together, and the multiple stator units 11 form a planar working area Q. The mover assembly 20 includes a power magnet, and the stator units 11 include drive coils. The mover assembly 20 can move within the planar working area Q under the drive of the stator assembly 10. The position detection component 30 is used to detect the real-time position of the mover assembly 20 within the planar working area Q. Furthermore, the magnetic motion platform also includes a controller (not shown), used to control the mover assembly 20 and the stator assembly 10 using the control method described below, so that the stator assembly 10 drives the mover assembly 20 to levitate and translate relative to the stator assembly 10. The remaining structure of the specific magnetic motion platform can be referenced from existing magnetic motion platforms; the embodiments of this invention will not be described in detail here.

[0023] Based on the aforementioned magnetic motion platform, such as Figure 2As shown, the control method for the magnetic motion platform provided in this embodiment of the invention includes the following steps: Step S102: Obtain the projection area of ​​the moving component on the planar working area when it moves, and determine the target stator unit based on the projection area and the stator area of ​​each stator unit.

[0024] In this context, the target stator unit is the stator unit covered by the passive sub-assembly. In practical applications, when the moving sub-assembly moves within a planar working area, since the planar working area consists of multiple stator units, some of these stator units are covered by the passive sub-assembly. Therefore, for ease of explanation, the stator unit covered by the passive sub-assembly among the multiple stator units is referred to as the target stator unit. For example, such as… Figure 3 As shown, at this time, the mover assembly 20 covers only one stator unit 11, that is, the number of target stator units is one; as Figure 4 As shown, at this time, the mover assembly 20 spans across two stator units 11, that is, it covers two stator units 11 simultaneously, and the number of target stator units is two; as Figure 5 As shown, at this time, the mover assembly 20 covers four stator units 11 simultaneously, that is, the number of target stator units is four.

[0025] It should be noted that as the real-time position of the mover assembly changes, the target stator unit also changes. In order to determine the target stator unit, this embodiment of the invention obtains the projection area of ​​the mover assembly on the planar working area when it moves, and determines the target stator unit based on the projection area and the stator area of ​​each stator unit.

[0026] Step S104: Determine the allocation weight of the target stator unit based on the projection area and the stator area of ​​the target stator unit.

[0027] Step S106: Obtain the preset driving force of the moving component, and determine the distribution force of the target stator unit based on the preset driving force and the distribution weight.

[0028] Step S108: Determine the drive current of the target stator based on the distribution force of the target stator unit, and control the target stator unit according to the drive current.

[0029] The control method for the magnetic motion platform provided in this embodiment of the invention involves the controller first acquiring the projection area of ​​the mover assembly on the planar working area and the stator area of ​​each stator unit to determine the target stator unit and its corresponding allocation weight; then acquiring the preset driving force of the mover assembly and determining the allocation force of the target stator unit based on the preset driving force and allocation weight; finally, determining the driving current of the target stator based on the allocation force of the target stator unit and controlling the target stator unit based on the driving current. Therefore, this control method, on the one hand, only requires the projection area of ​​the mover assembly on the planar working area and the stator area of ​​the target stator unit to determine the weighting of the target stator unit. The distribution force is determined based on the preset driving force and the distribution weight, and the target stator unit is controlled according to the driving current corresponding to the distribution force. Compared with related technical solutions, it eliminates the need for electromagnetic field finite element modeling or large matrix operations, thus improving computational efficiency. It can be completed within a 1ms control cycle, meeting the real-time control requirements at the 1kHz level. On the other hand, it only requires determining the dimensions of the projection area and the stator area of ​​the target stator unit to control the target stator unit, eliminating the need for extensive electromagnetic field calibration work for each mover assembly-stator unit combination. This simplifies calibration and provides good scalability. Furthermore, the projection area continuously changes with the real-time position of the mover assembly, causing a continuous change in the weighting of the target stator unit, resulting in a continuous change in the distribution force of the target stator unit. This avoids sudden force changes at the boundary, ensuring the smoothness of the mover assembly's movement and thus improving the control accuracy of the magnetic motion platform.

[0030] In one embodiment, determining a target stator unit based on the projection area and the stator area of ​​each stator unit includes: determining the overlap length of the mover assembly and each stator unit in the X and Y directions, respectively, based on the projection area and the stator area of ​​each stator unit; and selecting stator units whose overlap lengths in both the X and Y directions are greater than a preset threshold as target stator units.

[0031] Specifically, the projected area of ​​the mover assembly on the planar working area and the stator area of ​​each stator unit are both rectangular areas. For ease of explanation, let the dimensions of the projected area in the X and Y directions be Lx and Ly, respectively. Then, the half-dimensional dimension of the projected area in the X direction is Lx / 2, and the half-dimensional dimension of the projected area in the Y direction is Ly / 2. Similarly, taking the stator area of ​​any stator unit as an example, let the dimensions of the stator area in the X and Y directions be Sx and Sy, respectively. Then, the half-dimensional dimension of the stator area in the X direction is Sx / 2, and the half-dimensional dimension of the stator area in the Y direction is Sy / 2.

[0032] For each stator unit, the overlap lengths of the mover assembly and the stator unit in the X and Y directions are determined based on the projection area and the stator region of the stator unit, respectively. Specifically, the overlap length between the projection area and the stator region in the X direction is taken as the overlap length in the X direction, and the overlap length between the projection area and the stator region in the Y direction is taken as the overlap length in the Y direction. In particular, if the projection area and the stator region have no overlap length in the X and / or Y directions, the corresponding overlap length is set to 0.

[0033] After determining the overlap lengths of the mover assembly and each stator unit in the X and Y directions, respectively, it is determined whether the overlap lengths of the mover assembly and each stator unit in the X and Y directions are both greater than a preset threshold. If so, the stator unit is identified as the target stator unit; otherwise, the stator unit is a stator unit not covered by the stator assembly. The preset threshold is preferably 0.

[0034] Therefore, the embodiments of the present invention only need to determine the target stator unit covered by the passive sub-assembly based on the projection area and the size of the stator area of ​​each stator unit, so as to control the target stator unit. This eliminates the need for extensive electromagnetic field calibration work for each moving sub-assembly-stator unit combination, achieving simple calibration and good scalability. For example, when adding or removing stator units, only the stator layout information needs to be updated, such as updating the stator area of ​​the added or removed stator units. The control method does not need to be modified to determine the target stator unit.

[0035] In one embodiment, determining the allocation weight of the target stator unit based on the projection area and the stator area of ​​the target stator unit includes: (A1) determining the overlap area between the mover assembly and the target stator unit based on the projection area and the stator area of ​​the target stator unit; (A2) determining the coverage area ratio corresponding to the target stator unit based on the overlap area and the area of ​​the projection area; and determining the allocation weight of the target stator unit based on the coverage area ratio.

[0036] In step (A1), firstly, based on the projection area and the stator area of ​​the target stator unit, the first overlap length in the X direction and the second overlap length in the Y direction of the mover assembly and the target stator unit are determined; then, the overlap area is determined based on the first overlap length and the second overlap length. Specifically, based on the projection area and the stator area of ​​the target stator unit, the overlap lengths of the mover assembly and the target stator unit in the X and Y directions are determined respectively, and the overlap length in the X direction is called the first overlap length, and the overlap length in the Y direction is called the second overlap length. The product of the first overlap length and the second overlap length is then used as the overlap area.

[0037] Furthermore, in (A2), the overlapping area is divided by the area of ​​the projected region to obtain the coverage area ratio corresponding to the target stator unit. If there are multiple target stator units, the coverage area ratios of the multiple target stator units are normalized to obtain the allocation weights corresponding to the multiple target stator units respectively; wherein, the sum of the allocation weights corresponding to the multiple target stator units is 1.

[0038] For example, such as Figure 6 As shown, assume the projected area of ​​the mover assembly is a 155mm × 155mm square, and the stator area of ​​each stator unit is a 240mm × 240mm square. The dimensions of the projected area in the X direction and in the Y direction (Ly) are both 155mm, therefore the half-dimensions of the projected area in both the X and Y directions are 77.5mm. Similarly, the dimensions of the stator area in the X direction (Sx) and in the Y direction (Sy) are both 240mm, therefore the half-dimensions of the stator area in both the X and Y directions are 120mm.

[0039] For ease of explanation, we will take the example of the center of the moving component being located directly above the boundary of two adjacent stator units. In this case, the moving component covers two stator units simultaneously. The two adjacent stator units covered by the moving component are called target stator unit A and target stator unit B. The center of the moving component is located at the X-direction boundary of target stator unit A and target stator unit B. The center coordinate of target stator unit A in the X-direction is XA, the center coordinate of target stator unit B in the X-direction is XB, and the center coordinate of the moving component in the X-direction is XC. The projection interval of the moving component in the X-direction is [XC-77.5, XC+77.5].

[0040] Therefore, the overlap length between the mover assembly and the target stator unit A in the X direction is: OverlapXA = max(0, min(XC + 77.5, XA + 120) - max(XC - 77.5, XA - 120)); Since the mover assembly completely overlaps with the target stator unit A in the Y direction, the overlap length between the mover assembly and the target stator unit A in the Y direction is 155mm; Therefore, the coverage area ratio of the target stator unit A is A = (OverlapXA × 155) / (155mm × 155mm) = OverlapXA / 155.

[0041] Similarly, the overlap length between the mover assembly and the target stator unit B in the X direction is: OverlapXB = max(0, min(XC + 77.5, XB + 120) - max(XC - 77.5, XB - 120)); Since the mover assembly completely overlaps with the target stator unit B in the Y direction, the overlap length between the mover assembly and the target stator unit B in the Y direction is 155mm; Therefore, the coverage area ratio of the target stator unit B is B = (OverlapXB × 155) / (155mm × 155mm) = OverlapXB / 155.

[0042] Since the multiple target stator units include target stator unit A and target stator unit B, the coverage area ratio A of target stator unit A and the coverage area ratio B of target stator unit B are normalized to obtain the allocation weight of target stator unit A: WeightA = OverlapXA / (OverlapXA + OverlapXB), and the allocation weight of target stator unit B: WeightB = OverlapXB / (OverlapXA + OverlapXB).

[0043] Therefore, when the mover assembly moves from target stator unit A to target stator unit B, the weight distribution weight A of target stator unit A changes continuously from 1 to 0, and the weight distribution weight B of target stator unit B changes continuously from 0 to 1. Thus, the weight distribution weight of the target stator unit changes continuously with the real-time position of the mover assembly, achieving a smooth force distribution transition. This avoids sudden force changes at the boundary, ensures the smoothness of the mover assembly's motion, and improves the control accuracy of the magnetic motion platform.

[0044] Furthermore, after the allocation weights of the target stator unit are determined, the allocation force of the target stator unit is determined based on the preset driving force and the allocation weights. One method for determining the allocation force is as follows: the preset driving force includes a preset driving force in the X direction and a preset driving force in the Y direction; the allocation force includes an allocation force in the X direction and an allocation force in the Y direction; the allocation force of the target stator unit in the X direction is determined based on the preset driving force in the X direction and the allocation weights; and the allocation force of the target stator unit in the Y direction is determined based on the preset driving force and the allocation weights. Thus, force allocation for planar movement is achieved based on the preset driving force and the allocation weights of the target stator unit.

[0045] In another method for determining the distribution force, the preset driving force includes a preset rotational torque that rotates around the Z-axis, and the distribution force includes a distribution force in the X direction and a distribution force in the Y direction. The distribution torque of the target stator unit is determined based on the preset rotational torque and the distribution weight. The distribution force of the target stator unit in the X direction and the distribution force in the Y direction are determined based on the distribution torque, a first offset, and a second offset. The first offset is the offset of the center of the mover assembly relative to the center of the target stator unit in the X direction, and the second offset is the offset of the center of the mover assembly relative to the center of the target stator unit in the Y direction.

[0046] Specifically, the offset of the center of the mover assembly relative to the center of the target stator unit in the X direction (i.e., the first offset dx) and the offset of the center of the mover assembly relative to the center of the target stator unit in the Y direction (i.e., the second offset dy) are determined. The distribution torque Tz of the target stator unit is determined based on the preset rotational torque and distribution weight. Then, based on the distribution torque, the first offset, and the second offset, the distribution force Ftx of the target stator unit in the X direction is determined as -Tz×dy / (dx²+dy²+ε), and the distribution force Fty of the target stator unit in the Y direction is determined as Fty=Tz×dx / (dx²+dy²+ε). Here, ε represents a small positive number to prevent division by zero, and the unit is consistent with dx² or dy². The specific value can be set according to the actual situation. Therefore, based on the first and second offsets of the center of the mover assembly relative to the center of the target stator unit, the distribution torque of the target stator unit is converted into the distribution force (also called the additional tangential force) of the target stator unit in the X and Y directions.

[0047] Specifically, if the preset driving force includes not only the preset driving force in the X direction and the preset driving force in the Y direction, but also the preset rotational torque around the Z-axis, then on the one hand, the first distribution force and the first distribution force in the Y direction of the target stator are determined based on the preset driving force in the X direction, the preset driving force in the Y direction, and the distribution weight of the target stator unit; on the other hand, the distribution torque of the target stator unit is determined based on the preset rotational torque and the distribution weight of the target stator unit, and the second distribution force and the second distribution force in the X direction of the target stator unit are determined based on the distribution torque, the first offset, and the second offset; finally, the first distribution force and the second distribution force in the X direction of the target stator unit are taken as the target distribution force in the X direction of the target stator unit, and the first distribution force and the second distribution force in the Y direction of the target stator unit are taken as the target distribution force in the Y direction of the target stator unit.

[0048] For example, when the center of the mover assembly is located above the intersection of the four stator units, the mover assembly covers the four target stator units simultaneously. In each direction, the mover assembly overlaps with two target stator units, resulting in four coverage area ratios. After normalization, four allocation weights can be obtained to distribute the preset driving force to the four target stator units.

[0049] Assuming the center coordinates of the moving component are (XC, YC) and the center coordinates of the four target stator units are (X1, Y1), (X2, Y1), (X1, Y2) and (X2, Y2), respectively, calculate the overlap area between the moving component and each target stator unit, and determine the coverage area ratio corresponding to each target stator unit based on the overlap area and the area of ​​the projected region. After normalizing the four coverage area ratios, four allocation weights w1~w4 are obtained.

[0050] If the preset driving force includes not only the preset driving force in the X direction and the preset driving force in the Y direction, but also the preset rotational torque around the Z axis, then, based on the preset driving force in the X direction and the preset driving force in the Y direction, as well as the allocation weights w1~w4, the first distribution force in the X direction and the first distribution force in the Y direction for each target stator unit are determined respectively. On the other hand, the distribution torque of each target stator unit is determined according to the preset rotational torque and distribution weights w1~w4. For each target stator unit, the second distribution force in the X direction and the second distribution force in the Y direction of the target stator unit are determined according to the corresponding distribution torque, the first offset and the second offset. For example, for target stator unit 1, the distribution torque of target stator unit 1 is Tz1, the offset of the center of the mover assembly relative to the center of target stator unit 1 in the X direction is dx1, and the offset of the center of the mover assembly relative to the center of target stator unit 1 in the Y direction is dy1. Then the second distribution force of target stator unit 1 in the X direction is Ftx1=-Tz1×dy1 / (dx1²+dy1²+ε), and the second distribution force of target stator unit 1 in the Y direction is Fty1=Tz1×dx1 / (dx1²+dy1²+ε).

[0051] Finally, for each target stator unit, the first and second distribution forces in the X direction are taken as the target distribution force in the X direction, and the first and second distribution forces in the Y direction are taken as the target distribution force in the Y direction. It should be noted that the first and second distribution forces in the X direction can be directly added together to obtain the target distribution force in the X direction, or weights can be assigned to the first and second distribution forces respectively, and the target distribution force in the X direction can be calculated based on the first and second distribution forces and their corresponding weights. Similarly, the first and second distribution forces in the Y direction can be directly added together to obtain the target distribution force in the Y direction, or weights can be assigned to the first and second distribution forces respectively, and the target distribution force in the Y direction can be calculated based on the first and second distribution forces and their corresponding weights.

[0052] Furthermore, after determining the target distributed force of the target stator unit in the X and Y directions, the three-phase drive current of the target stator is obtained through Clarke decomposition. For the three-phase drive current, Iu = (Fxlocal + Fzlocal) / Kt, Iv = (-0.5×Fxlocal + 0.866×Fylocal + Fzlocal) / Kt, Iw = (-0.5×Fxlocal-0.866×Fylocal + Fzlocal) / Kt; Fxlocal represents the target distributed force of the target stator unit in the X direction, Fylocal represents the target distributed force of the target stator unit in the Y direction, Fzlocal represents the target distributed force of the target stator unit in the Z direction, and Kt represents the force constant in N / A.

[0053] Specifically, the value of Fzlocal can be set according to the load and the model of the planar motor. In addition, the planar motor provides levitation force to enable the stator assembly to drive the rotor assembly to levitate and translate relative to the stator assembly. The X, Y, and Z coils in the stator unit can be set individually or in combination, depending on the actual situation.

[0054] In one embodiment, the method further includes: when multiple moving parts simultaneously cover the same target stator unit, determining the drive current generated by the multiple moving parts on the target stator unit respectively; determining the total drive current based on the drive current of the multiple moving parts; and controlling the target stator unit based on the total drive current.

[0055] Specifically, when multiple mover components simultaneously cover the same target stator unit, the driving current generated by each mover component on the target stator unit is superimposed to obtain the total driving current. That is, in the total driving current, Iutotal=ΣIuk, Ivtotal=ΣIvk, Iwtotal=ΣIwk, where k represents the mover number covering the target stator unit, Iuk represents Iu generated by the k-th mover component, Ivk represents Iv generated by the k-th mover component, and Iwk represents Iw generated by the k-th mover component. In particular, since the electromagnetic force (distribution force) F and the current I satisfy the linear relationship F=Kt×I, the linear superposition of the driving current is equivalent to the linear superposition of the electromagnetic force. That is, the linear superposition of the current is physically equivalent and correct.

[0056] For example, suppose two moving parts M1 and M2 simultaneously cover the target stator unit S. The weight assigned to the target stator unit S by moving part M1 is w1, and the driving current generated by moving part M1 on the target stator unit S is (Iu1, Iv1, Iw1). Similarly, the weight assigned to the target stator unit S by moving part M2 is w2, and the driving current generated by moving part M2 on the target stator unit S is (Iu2, Iv2, Iw2). Then the total driving current of the target stator unit S is IuS = Iu1 + Iu2, IvS = Iv1 + Iv2, and IwS = Iw + Iw2.

[0057] It should be noted that when multiple moving parts cover the same target stator unit at the same time, the total driving current can be obtained by directly summing the driving current generated by each moving part to the target stator unit. In some scenarios, a weight can also be set for the driving current of each moving part, and the total driving current can be calculated based on the driving current generated by each moving part to the target stator unit and its corresponding weight.

[0058] Therefore, the control method of the magnetic motion platform provided in this embodiment of the invention can directly synthesize the driving currents of multiple moving parts by superposition principle when multiple moving parts simultaneously cover the same target stator unit. This eliminates the need for arbitration or scheduling and is physically equivalent to the linear superposition of electromagnetic forces. As a result, it is applicable to the case of multiple moving parts and further enriches the application scenarios.

[0059] Furthermore, based on the above method embodiments, this invention also provides a magnetic motion platform, including: a controller, a stator assembly, a mover assembly, and a position detection assembly; wherein, the stator assembly includes multiple stator units forming a planar working area, the mover assembly includes a power magnet, the stator units include drive coils, and the mover assembly can move within the planar working area under the drive of the stator assembly; the position detection assembly is used to detect the real-time position of the mover assembly within the planar working area; and the controller is used to control the magnetic motion platform using the above-described magnetic motion platform control method.

[0060] The magnetic motion platform provided in this embodiment of the invention has the same technical features as the control method of the magnetic motion platform provided in the above embodiments, so it can also solve the same technical problems and achieve the same technical effects.

[0061] Furthermore, embodiments of the present invention also provide a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the aforementioned control method for the magnetic motion platform.

[0062] The control method and computer program product of the magnetic motion platform provided in the embodiments of the present invention include a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the methods described in the preceding method embodiments. For specific implementation, please refer to the method embodiments, which will not be repeated here.

[0063] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the system and apparatus described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0064] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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 connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0065] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0066] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0067] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A control method for a magnetic motion platform, characterized in that, The magnetic motion platform includes a stator assembly, a mover assembly, and a position detection assembly. The stator assembly includes multiple stator units that form a planar working area. The mover assembly includes a power magnet, and each stator unit includes a drive coil. The mover assembly can move within the planar working area under the drive of the stator assembly. The position detection assembly is used to detect the real-time position of the mover assembly within the planar working area. The control method includes: The projection area of ​​the moving part assembly on the planar working area is obtained when the moving part assembly moves. The target stator unit is determined based on the overlap area between the projection area and the stator area of ​​each stator unit. The target stator unit is the stator unit covered by the moving part assembly. The coverage area ratio of the target stator unit is determined based on the projection area and the stator area of ​​the target stator unit, and the allocation weight of the target stator unit is determined based on the coverage area ratio. Obtain the preset driving force of the mover assembly, and determine the allocated force of the target stator unit based on the preset driving force and the allocation weight; The driving current of the target stator is determined based on the distribution force of the target stator unit, and the target stator unit is controlled based on the driving current.

2. The control method according to claim 1, characterized in that, The overlapping area includes the overlap lengths in the X and Y directions; Determining the target stator unit based on the overlap area between the projection area and the stator areas of each stator unit includes: Based on the projection area and the stator area of ​​each stator unit, the overlap length of the mover assembly and each stator unit in the X and Y directions is determined respectively. The stator unit whose overlap length in both the X and Y directions is greater than a preset threshold is selected as the target stator unit.

3. The control method according to claim 1, characterized in that, The step of determining the coverage area ratio corresponding to the target stator unit based on the projection area and the stator area of ​​the target stator unit, and determining the allocation weight of the target stator unit based on the coverage area ratio, includes: The overlap area between the mover assembly and the target stator unit is determined based on the projection area and the stator area of ​​the target stator unit. The coverage area ratio corresponding to the target stator unit is determined based on the overlapping area and the area of ​​the projected region. The allocation weight of the target stator unit is determined based on the coverage area ratio.

4. The control method according to claim 3, characterized in that, If there are multiple target stator units, determining the allocation weight of the target stator units based on the coverage area ratio includes: The coverage area ratios of the multiple target stator units are normalized to obtain the allocation weights corresponding to the multiple target stator units respectively; wherein the sum of the allocation weights corresponding to the multiple target stator units is 1.

5. The control method according to claim 3, characterized in that, Determining the overlap area between the mover assembly and the target stator unit based on the projection area and the stator region of the target stator unit includes: Based on the projection area and the stator area of ​​the target stator unit, determine the first overlap length in the X direction and the second overlap length in the Y direction between the mover assembly and the target stator unit; The overlapping area is determined based on the first overlap length and the second overlap length.

6. The control method according to claim 1, characterized in that, The preset driving force includes a preset driving force in the X direction and a preset driving force in the Y direction, and the distribution force includes a distribution force in the X direction and a distribution force in the Y direction. Determining the distribution force of the target stator unit based on the preset driving force and the distribution weight includes: The distribution force of the target stator unit in the X direction is determined based on the preset driving force in the X direction and the distribution weight, and the distribution force of the target stator unit in the Y direction is determined based on the preset driving force in the Y direction and the distribution weight.

7. The control method according to claim 1, characterized in that, The preset driving force includes a preset rotational torque about the Z-axis, and the distribution force includes a distribution force in the X direction and a distribution force in the Y direction. Determining the distribution force of the target stator unit based on the preset driving force and the distribution weight includes: The allocated torque of the target stator unit is determined based on the preset rotational torque and the allocation weight. Based on the distributed torque, the first offset, and the second offset, the distributed force of the target stator unit in the X direction and the distributed force in the Y direction are determined; wherein, the first offset is the offset of the center of the mover assembly relative to the center of the target stator unit in the X direction, and the second offset is the offset of the center of the mover assembly relative to the center of the target stator unit in the Y direction.

8. The control method according to claim 1, characterized in that, The method further includes: When multiple moving parts simultaneously cover the same target stator unit, determine the driving current generated by each of the multiple moving parts on the target stator unit; The total drive current is determined based on the drive currents of the multiple moving parts, and the target stator unit is controlled based on the total drive current.

9. A magnetic motion platform, characterized in that, include: The system includes a controller, a stator assembly, a mover assembly, and a position detection assembly. The stator assembly comprises multiple stator units that form a planar working area. The mover assembly includes a power magnet, and each stator unit includes a drive coil. The mover assembly can move within the planar working area under the drive of the stator assembly. The position detection assembly is used to detect the real-time position of the mover assembly within the planar working area. The controller is used to control the magnetic motion platform using the control method described in any one of claims 1-8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a processor, performs the steps of the control method according to any one of claims 1-8.

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