Mobile platform type electromagnetic control system

Abstract

The invention provides a mobile platform type electromagnetic control system, which comprises a basic box body, a plurality of groups of electromagnetic coils and an upper computer, and is characterized in that the basic box body is provided with a plurality of stepping motors, an output shaft of each stepping motor is provided with an electric brush shaft sleeve, two ends of each electric brush shaft sleeve are provided with two electric brushes, and the outer side of each electric brush is provided with a relay plate; each stepping motor rotates to drive the two electric brushes to make contact with or not make contact with the two corresponding relay plates, each set of electromagnetic coils comprises two electromagnetic coils, and the two ends of one electromagnetic coil are electrically connected with the two relay plates corresponding to one stepping motor respectively. The two ends of the other electromagnetic coil are electrically connected with the two electric brushes corresponding to the stepping motor respectively, and the upper computer controls the stepping motors to rotate forwards or backwards. According to the invention, the switching of the connection modes of the electromagnetic coils can be realized through the control of the stepping motor, and the method can be effectively applied to the current control of various types of electromagnetic coils.

Description

Technical Field

[0001] The present invention relates to the field of electromagnetic drive technology, and in particular to a mobile platform type electromagnetic control system. Background Art

[0002] Microrobots are small-scale robots with a scale of sub-millimeter or less that can move autonomously through manipulation. Due to the biocompatibility, high real-time and high controllability of magnetic fields, it is an important manipulation method for microrobots in the biomedical field. However, magnetically driven microrobots are still limited in terms of range of motion and high-frequency precision manipulation. Traditional electromagnetic coil platforms are used in platform connection devices, and the position and size of the electromagnetic coils are fixed. When the size of the electromagnetic coils needs to be changed, the entire electromagnetic coil system must be completely replaced, and the power must be turned off and manual operation is required when changing the connection method of the electromagnetic coils. The corresponding closed-loop control algorithm does not have universality and high adjustability due to differences in the composition and environment of the electromagnetic coil system, and the accuracy of generating high-frequency magnetic fields is insufficient. Summary of the invention

[0003] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a mobile platform type electromagnetic control system, which can realize the conversion of the Helmholtz and Maxwell connection modes of the electromagnetic coil by controlling a stepper motor, and can be effectively applied to the current control of various types of electromagnetic coils.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A mobile platform type electromagnetic control system, comprising:

[0006] The basic box is provided with a plurality of stepper motors, each of which has a brush shaft sleeve on its output shaft, a horizontally arranged cross arm on the brush shaft sleeve, two brushes at both ends of the cross arm, a relay plate outside each brush, and each of which rotates to drive the two brushes to contact or not contact the corresponding two relay plates;

[0007] A plurality of groups of electromagnetic coils, each group of electromagnetic coils includes two electromagnetic coils, two ends of one electromagnetic coil are electrically connected to two relay plates corresponding to a stepping motor, and two ends of another electromagnetic coil are electrically connected to two brushes corresponding to the stepping motor;

[0008] The host computer controls the three stepper motors to rotate forward or reverse.

[0009] Furthermore, it also includes a rotary encoder, which is fixed on the output shaft of the stepper motor, and the brush shaft sleeve is fixed on the output shaft of the rotary encoder.

[0010] Furthermore, the basic box is fixed on the platform connecting device, and the platform connecting device is slidably connected to the movable platform so that the platform connecting device can slide on the movable platform.

[0011] Further, the electromagnetic coil is an X-axis electromagnetic coil, a Y-axis electromagnetic coil or a Z-axis electromagnetic coil, and further includes a first electromagnetic coil fixing part, a second electromagnetic coil fixing part and a third electromagnetic coil fixing part;

[0012] The two X-axis electromagnetic coils are respectively arranged in two first electromagnetic coil fixing members in a one-to-one correspondence, and the two first electromagnetic coil fixing members are slidably connected to the basic box in a horizontal transverse direction to drive the two X-axis electromagnetic coils to slide in a horizontal transverse direction relative to the basic box to generate a magnetic field in the X-axis direction;

[0013] The two Y-axis electromagnetic coils are respectively arranged in the other two second electromagnetic coil fixing members in a one-to-one correspondence, and the other two first electromagnetic coil fixing members are slidably connected to the basic box in a horizontal transverse direction to drive the two Y-axis electromagnetic coils to slide in a horizontal transverse direction relative to the basic box to generate a Y-axis direction magnetic field;

[0014] The two Z-axis electromagnetic coils are respectively arranged in two third electromagnetic coil fixing parts in a one-to-one correspondence, and the two third electromagnetic coil fixing parts are vertically slidably connected to the basic box to drive the two Z-axis electromagnetic coils to slide vertically relative to the basic box to generate a Z-axis magnetic field.

[0015] Furthermore, a central area is provided on the basic box body, and a plurality of stepper motors include an X-axis stepper motor, a Y-axis stepper motor and a Z-axis stepper motor, all of which are arranged in the central area. Four sliding grooves are respectively extended outward from the four corners of the central area, and a wedge-shaped structure is formed between the sliding grooves. The first electromagnetic coil fixing part or the second electromagnetic coil fixing part is fixed to the electromagnetic coil moving part, and accommodating grooves are respectively provided on both sides of the electromagnetic coil moving part. Shoulder blocks are built in the accommodating grooves, and the shoulder blocks are elastically connected to the accommodating grooves through elastic parts. The middle part of the electromagnetic coil moving part is located on the wedge-shaped structure and the two shoulder blocks on both sides are respectively slidably connected to the two sliding grooves in a one-to-one correspondence.

[0016] Furthermore, each of the sliding grooves is provided with an X-axis electrical outer spring sheet and a Y-axis electrical outer spring sheet on both sides close to the two wedge-shaped structures;

[0017] The two relay plates corresponding to the X-axis stepper motor are electrically connected to two of the X-axis electrical outer springs, the two brushes corresponding to the X-axis stepper motor are electrically connected to the other two X-axis electrical outer springs, and both ends of the two X-axis electromagnetic coils are electrically connected to X-axis electrical inner springs, wherein the two X-axis electrical outer springs electrically connected to one X-axis electromagnetic coil can be in contact with or not in contact with the two X-axis electrical inner springs electrically connected to the two relay plates to achieve the connection and disconnection of the X-axis electromagnetic coil, and the two X-axis electrical outer springs electrically connected to the other X-axis electromagnetic coil can be in contact with or not in contact with the two X-axis electrical inner springs electrically connected to the two brushes to achieve the connection and disconnection of the X-axis electromagnetic coil;

[0018] The two relay plates corresponding to the Y-axis stepper motor are electrically connected to two of the Y-axis electrical outer reeds, the two brushes corresponding to the Y-axis stepper motor are electrically connected to the other two Y-axis electrical outer reeds, and both ends of the two Y-axis electromagnetic coils are electrically connected to Y-axis electrical inner reeds, wherein the two Y-axis electrical outer reeds electrically connected to one Y-axis electromagnetic coil can contact or not contact the two Y-axis electrical inner reeds electrically connected to the two relay plates to achieve the connection and disconnection of the Y-axis electromagnetic coil, and the two Y-axis electrical outer reeds electrically connected to the other Y-axis electromagnetic coil can contact or not contact the two Y-axis electrical inner reeds electrically connected to the two brushes to achieve the connection and disconnection of the Y-axis electromagnetic coil.

[0019] Furthermore, the third electromagnetic coil fixing part is driven to slide in a vertical direction relative to the base box body by an electromagnetic coil driving mechanism, and the electromagnetic coil driving mechanism includes a screw motor and a rotating screw, and the rotating screw is fixedly connected to the output shaft of the screw motor, and the two third electromagnetic coil fixing parts are slidably connected to the rotating screw at a certain distance.

[0020] Furthermore, the host computer has a built-in closed-loop control algorithm module, which includes a signal preprocessing module, a Kalman filter, a Smith predictive corrector and an optimal controller, wherein

[0021] The signal preprocessing module is used to calibrate the electromagnetic coil to obtain the current of the electromagnetic coil;

[0022] The Kalman filter is used to determine the process noise and the measurement noise of the current of the electromagnetic coil;

[0023] The Smith predictive corrector is used to delay the control process, compare and correct the estimated value obtained by the Kalman filter;

[0024] The optimal controller is used to output the optimal current of the stepper motor.

[0025] Furthermore, a state feedback controller is established in the closed-loop control algorithm module, and adaptive control is performed through the state feedback controller.

[0026] Furthermore, the signal preprocessing module calibrates the electromagnetic coil through the current sensor to obtain the current of the electromagnetic coil. The calculation formula is:

[0027] U o =k 1 ·U+k 2 I

[0028] Among them, U o is the output voltage of the sensor chip, U is the bias voltage of the sensor chip, I is the current of the electromagnetic coil, k 1 and k 2 is the corresponding proportional coefficient;

[0029] The Kalman filter determines the calculation formula for the process noise and measurement noise of the electromagnetic coil current:

[0030]

[0031] in, is the estimated system state value of the Kalman filter, To estimate the magnetic field value, is the estimated current value, D is the time domain delay coefficient of the system, is the ratio of the sampling frequency to the output frequency rounded up, P is the covariance matrix of the estimation error, and R v is the measurement noise matrix, A j , B j , C j , D j They correspond to the parameter matrices of the system model, k represents the current time step of the host computer cycle, α represents the mapping relationship between the coil current and the generated magnetic field, and X j (k) is the system state variable at time k, u j (kD j ) is the PWM voltage corresponding to the current required by the current axis to generate a magnetic field;

[0032] The Smith predictive corrector delays the control process, compares the estimated value obtained by the Kalman filter and makes corrections using the following calculation formula:

[0033]

[0034]

[0035] Among them, X p (k) and I p(k) represents the predicted state value and the predicted current value of the Smith predictive corrector system without time delay at time step k, X pd (k) and I pd (k) represents the state prediction value of the Smith predictor corrector delay system and the delay-free current prediction value at time step k;

[0036] The calculation formula for the optimal current of the optimal controller output electromagnetic coil is:

[0037]

[0038] in, represents the Kalman prediction value for k+1 time step based on k time step, X(k) and I(k) represent the system state value and current value of k time step for optimal controller control obtained by Smith predictive corrector part, Indicates based on u j The Kalman prediction value is calculated based on (kD) and the mapping relationship between the electromagnetic coil voltage and current β.

[0039] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0040] A mobile platform type electromagnetic control system provided by the present invention controls a plurality of stepper motors to rotate forward or reversely through a host computer, so that a brush shaft sleeve can drive two brushes to rotate and thus change the current flow direction of a plurality of groups of electromagnetic coils, thereby changing the type of electromagnetic coil connection mode, realizing the conversion of the Helmholtz and Maxwell connection modes of the electromagnetic coils, and can be effectively applied to the current control of various types of electromagnetic coils. When each stepper motor rotates to drive the two brushes to contact the corresponding two relay plates, two electromagnetic coils in one group of electromagnetic coils are connected in parallel, which can realize the superposition of magnetic fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0042] Figure 1 It is a general schematic diagram of the present invention;

[0043] Figure 2 A cross-sectional view of a basic box of the electromagnetic coil hardware system of the present invention;

[0044] Figure 3 It is a schematic diagram of the electromagnetic coil moving part of the present invention sliding on the basic box body;

[0045] Figure 4It is a schematic diagram of the first electromagnetic coil fixing member of the present invention being fixed to the electromagnetic coil moving member;

[0046] Figure 5 This is a schematic diagram of the current commutation device of the present invention;

[0047] Figure 6 A front view of the electromagnetic coil hardware system of the present invention;

[0048] Figure 7 The third electromagnetic coil fixing member of the electromagnetic coil hardware system of the present invention;

[0049] Figure 8 A bottom view of a basic box of the electromagnetic coil hardware system of the present invention;

[0050] Fig. 9 It is a front view of the coil fixing device of the present invention;

[0051] Fig.10 It is a schematic diagram of current generation, current collection and closed-loop control of the present invention.

[0052] In the figure: 101, basic box; 102, platform connecting device; 201, sliding groove; 202, wedge structure; 203, shoulder block; 204, electrical inner spring; 205, operating rod; 206, blocking plate; 207, elastic member; 208, adjusting bolt; 209, X-axis electromagnetic coil; 210, first electromagnetic coil fixing member; 211, z-axis electromagnetic coil; 212, support rod; 213, fixing bolt; 214, accommodating groove; 215, third electromagnetic coil fixing member; 216, electrical outer spring; 217, electromagnetic coil moving member; 301, relay board; 302, cross arm; 303, stepping motor; 304, rotary encoder; 305, brush shaft sleeve; 306, wire; 307, brush. DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0054] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0055] Example 1

[0056] In the related art, the traditional electromagnetic coil platform is applied to the platform connection device 102, and the position and size of the electromagnetic coil are fixed. When the size of the electromagnetic coil needs to be changed, the entire electromagnetic coil system must be completely replaced, and the connection method of the electromagnetic coil needs to be changed by power off and manual operation. This embodiment provides a mobile platform type electromagnetic control system, which can realize the conversion of the Helmholtz and Maxwell connection methods of the electromagnetic coil through the control of the stepper motor 303, and can be effectively applied to the current control of various types of electromagnetic coils, and the connection method of the electromagnetic coil can be changed without power off and manual operation.

[0057] Embodiment 1 provides a mobile platform type electromagnetic control system, such as Figure 2 , Figure 3 and Figure 5 As shown, including:

[0058] The basic box 101 is provided with three stepper motors 303, and the three stepper motors 303 are respectively an X-axis stepper motor, a Y-axis stepper motor and a Z-axis stepper motor;

[0059] A current commutation device, including a brush sleeve 305, a brush 307 and a relay plate 310. The brush sleeve 305 is fixed on the output shaft of each stepping motor 303. The brush sleeve 305 is provided with a horizontally arranged cross arm 302. Both ends of the cross arm 302 are provided with brushes 307. Two oppositely arranged relay plates 310 are provided on the outer side of each stepping motor 303. Each relay plate 310 is provided on the outer side of a brush 307. Each stepping motor 303 rotates to drive the two brushes 307 to contact or not contact the corresponding two relay plates 310.

[0060] 3 groups of electromagnetic coils, each group of electromagnetic coils includes 2 electromagnetic coils, two ends of one electromagnetic coil are respectively electrically connected to two relay plates 310 corresponding to a stepping motor 303 through a wire 306, and two ends of another electromagnetic coil are respectively electrically connected to two brushes 307 corresponding to the stepping motor 303 through a wire 306;

[0061] The host computer controls the three stepping motors 303 to rotate forward or reverse.

[0062] The present embodiment provides a mobile platform type electromagnetic control system. During use, the upper computer controls the three stepper motors 303 to rotate forward or reverse, so that the brush shaft sleeve 305 drives the two brushes 307 to rotate, thereby changing the current flow direction of the three groups of electromagnetic coils, thereby changing the type of electromagnetic coil connection method, realizing the conversion of the Helmholtz and Maxwell connection methods of the electromagnetic coils, and can be effectively applied to the current control of various types of electromagnetic coils.

[0063] For example, if the Helmholtz connection is marked as 00 and the Maxwell connection is marked as 01, the motor is judged to be rotating forward when 00, and it rotates 180° as Maxwell connection when receiving the command from the host computer. The encoder recognizes 01, and the host computer determines that the stepper motor 303 is reversed based on the recognition. Therefore, after receiving the command, it rotates 180° in the opposite direction as Helmholtz connection and re-identifies as 00, which can effectively avoid line entanglement.

[0064] In this embodiment, when each stepping motor 303 rotates to drive the two brushes 307 to contact the corresponding two relay plates 310, two electromagnetic coils in one set of electromagnetic coils are connected in parallel, so that the superposition of magnetic fields can be achieved.

[0065] In this embodiment, Figure 2 As shown, the three groups of electromagnetic coils include one group of X-axis electromagnetic coils 209 , one group of Y-axis electromagnetic coils, and one group of z-axis electromagnetic coils 211 . One group of X-axis electromagnetic coils 209 includes two X-axis electromagnetic coils 209 , one group of Y-axis electromagnetic coils includes two Y-axis electromagnetic coils, and one group of z-axis electromagnetic coils 211 includes two z-axis electromagnetic coils 211 .

[0066] Specifically, of the two X-axis electromagnetic coils 209 , two ends of one X-axis electromagnetic coil 209 are electrically connected to two relay boards 310 corresponding to the X-axis stepper motor, and two ends of the other X-axis electromagnetic coil 209 are electrically connected to two brushes 307 corresponding to the X-axis stepper motor.

[0067] Two Y-axis electromagnetic coils, two ends of one Y-axis electromagnetic coil are electrically connected to two relay boards 310 corresponding to the Y-axis stepping motor, and two ends of the other Y-axis electromagnetic coil are electrically connected to two brushes 307 corresponding to the Y-axis stepping motor.

[0068] Two z-axis electromagnetic coils 211, two ends of one z-axis electromagnetic coil 211 are electrically connected to two relay boards 310 corresponding to the Z-axis stepping motor, and two ends of the other z-axis electromagnetic coil 211 are electrically connected to two brushes 307 corresponding to the Z-axis stepping motor.

[0069] like Figure 1 As shown, the two ends of the upper z-axis electromagnetic coil are electrically connected to the two brushes 307 corresponding to the Z-axis stepper motor, and the two ends of the lower z-axis electromagnetic coil are electrically connected to the two relay boards 310 corresponding to the Z-axis stepper motor.

[0070] The host computer controls the forward or reverse rotation of the X-axis stepper motor, the Y-axis stepper motor and the Z-axis stepper motor.

[0071] In this embodiment, Figure 5 As shown, a rotary encoder 304 is also included, through which the rotation state of the output shaft of the stepper motor 303 can be recorded. In this embodiment, the rotary encoder 304 is fixed on the output shaft of the stepper motor 303, and the brush shaft sleeve 305 is fixed on the output shaft of the rotary encoder 304.

[0072] In this embodiment, Figure 8 As shown, the basic box 101 is fixed on the platform connecting device 102, and the platform connecting device 102 is slidably connected to the movable platform so that the platform connecting device 102 can slide on the movable platform to achieve the conversion of the magnetic field position.

[0073] In this embodiment, Figure 2-Figure 6 As shown, in order to facilitate the on-off of the current in the electromagnetic coil, the two ends of each electromagnetic coil are electrically connected to the two electrical inner springs 204 respectively, and the relay plate 310 and the brush 307 are electrically connected to the electrical outer spring 216. The on-off of the current in the electromagnetic coil is achieved by the contact or non-contact between the electrical inner spring 204 and the electrical outer spring 216.

[0074] In this embodiment, in order to adjust the type and size of the magnetic field generated by the electromagnetic coil, the selection of magnetic field types such as circular, conical, vibration, etc. and the selection of frequency, amplitude, pitch angle, etc. are included. Three groups of electromagnetic coil fixings are also included, each group of electromagnetic coil fixings includes two electromagnetic coil fixings, each electromagnetic coil is arranged in one electromagnetic coil fixing, and the electromagnetic coil fixing is slidably connected to the basic box 101.

[0075] In this embodiment, in order to facilitate the sliding connection between the electromagnetic coil fixing part and the base box 101 to adjust the type and size of the magnetic field generated by the electromagnetic coil, the electromagnetic coil fixing part includes two first electromagnetic coil fixing parts 210, two second electromagnetic coil fixing parts and two third electromagnetic coil fixing parts 215. The X-axis electromagnetic coil 209 is arranged in the first electromagnetic coil fixing part 210, the Y-axis electromagnetic coil is arranged in the second electromagnetic coil fixing part, and the Z-axis electromagnetic coil 211 is arranged in the third electromagnetic coil fixing part 215.

[0076] Among them, the two first electromagnetic coil fixing members 210 are respectively provided with two X-axis electromagnetic coils 209, the two first electromagnetic coil fixing members 210 are slidably connected to the basic box 101 in the horizontal transverse direction to drive the two X-axis electromagnetic coils 209 to slide in the horizontal transverse direction relative to the basic box 101 to generate an X-axis direction magnetic field, the two second electromagnetic coil fixing members are slidably connected to the basic box 101 in the horizontal longitudinal direction to drive the two Y-axis electromagnetic coils to slide in the horizontal longitudinal direction relative to the basic box 101 to generate a Y-axis direction magnetic field, and the two third electromagnetic coil fixing members 215 are slidably connected to the basic box 101 in the vertical direction to drive the two Z-axis electromagnetic coils 211 to slide in the vertical direction relative to the basic box 101 to generate a Z-axis direction magnetic field.

[0077] In this embodiment, Figure 2 and Figure 4 As shown, a central area is provided on the basic box body 101, and three stepper motors 303 including an X-axis stepper motor, a Y-axis stepper motor and a Z-axis stepper motor are all provided in the central area. Four sliding grooves 201 are respectively extended outward from the four corners of the central area, and a wedge-shaped structure 202 is formed between the sliding grooves 201 in pairs. The four sliding grooves 201 are X-shaped, and the first electromagnetic coil fixing part 210 or the second electromagnetic coil fixing part is fixed to the electromagnetic coil moving part 217. The electromagnetic coil moving part 217 drives the first electromagnetic coil fixing part 210 to slide in the horizontal transverse direction or drives the second electromagnetic coil fixing part to slide in the horizontal longitudinal direction.

[0078] The electromagnetic coil moving part 217 is respectively provided with a receiving groove 214 on both sides, and a shoulder block 203 is built in the receiving groove 214. The shoulder block 203 and the receiving groove 214 are elastically connected by an elastic member 207. The middle part of the electromagnetic coil moving part 217 is located on the wedge structure 202 and the two shoulder blocks 203 on both sides are respectively slidably connected to the two sliding grooves 201 in a one-to-one manner.

[0079] In this embodiment, the elastic member 207 is a spring.

[0080] In this embodiment, Figure 3 , Figure 4 and Fig. 9As shown, in order to fix the position of the electromagnetic coil moving member 217, an operating rod 205 is slidably connected in the receiving groove 214, and a blocking plate 206 is rotatably connected to the operating rod 205. The blocking plate 206 is rotated relative to the operating rod 205 to be in a first position and a second position;

[0081] When the blocking plate 206 is in the first position, the blocking plate 206 clamps the shoulder block 203 to prevent the shoulder block 203 from moving, thereby preventing the electromagnetic coil moving member 217 from driving the first electromagnetic coil fixing member 210 to move;

[0082] When the blocking plate 206 is at the second position, the blocking plate 206 releases the shoulder block 203 to enable the shoulder block 203 to move, thereby enabling the electromagnetic coil moving member 217 to drive the first electromagnetic coil fixing member 210 to move.

[0083] In this embodiment, Figure 2-Figure 4 As shown, electrical outer springs 216 are provided on both sides of the electromagnetic coil moving part 217, the two ends of the electromagnetic coil on the first electromagnetic coil fixing part 210 are electrically connected to the two electrical outer springs 216 respectively, and the two ends of the electromagnetic coil on the second electromagnetic coil fixing part are electrically connected to the two electrical outer springs 216 respectively. Electrical inner springs 204 are provided on both sides of each sliding groove 201 close to the two wedge-shaped structures 202. The electromagnetic coil moving part 217 drives the first electromagnetic coil fixing part 210 or the second electromagnetic coil fixing part to slide relative to the sliding groove 201 so that the electrical inner springs 204 and the electrical outer springs 216 are in contact or non-contact with each other one by one to realize the connection and disconnection of the current in the X-axis electromagnetic coil 209 or the Y-axis electromagnetic coil.

[0084] In this embodiment, the electrical outer spring 216 is an X-axis electrical outer spring and a Y-axis electrical outer spring.

[0085] In this embodiment, Figure 2-Figure 4 As shown, in order to further adjust the type and size of the magnetic field generated by the electromagnetic coil, each sliding groove 201 is respectively provided with an X-axis electrical outer reed and a Y-axis electrical outer reed on both sides close to the two wedge-shaped structures 202. In this embodiment, a total of 4 X-axis electrical outer reeds and 4 Y-axis electrical outer reeds are provided. Both sides of the two horizontal wedge-shaped structures 202 are provided with X-axis electrical outer reeds, and both sides of the two horizontal longitudinal wedge-shaped structures 202 are provided with Y-axis electrical outer reeds.

[0086] Specifically, Figure 2-Figure 4As shown, the two relay plates 310 corresponding to the X-axis stepper motor are electrically connected to the two X-axis electrical outer springs, the two brushes 307 corresponding to the X-axis stepper motor are electrically connected to the two X-axis electrical outer springs, and both ends of the two X-axis electromagnetic coils 209 are electrically connected to the X-axis electrical inner springs 204. Among them, the two X-axis electrical outer springs electrically connected to one X-axis electromagnetic coil 209 can be in contact or not in contact with the two X-axis electrical inner springs 204 electrically connected to the two relay plates 310 to achieve the connection and disconnection of the X-axis electromagnetic coil 209, and the two X-axis electrical outer springs electrically connected to the other X-axis electromagnetic coil 209 can be in contact or not in contact with the two X-axis electrical inner springs 204 electrically connected to the two brushes 307 to achieve the connection and disconnection of the X-axis electromagnetic coil 209.

[0087] The two relay plates 310 corresponding to the Y-axis stepper motor are electrically connected to the two Y-axis electrical outer springs, the two brushes 307 corresponding to the Y-axis stepper motor are electrically connected to the two Y-axis electrical outer springs, and both ends of the two Y-axis electromagnetic coils are electrically connected to the Y-axis electrical inner springs 204. Among them, the two Y-axis electrical outer springs electrically connected to one Y-axis electromagnetic coil can be in contact with or not in contact with the two Y-axis electrical inner springs 204 electrically connected to the two relay plates 310 to achieve the connection and disconnection of the Y-axis electromagnetic coil, and the two Y-axis electrical outer springs electrically connected to the other Y-axis electromagnetic coil can be in contact with or not in contact with the two Y-axis electrical inner springs 204 electrically connected to the two brushes 307 to achieve the connection and disconnection of the Y-axis electromagnetic coil.

[0088] In this embodiment, Figure 4 As shown, the first electromagnetic coil fixing member 210 includes a first supporting seat and a first supporting cover. The first supporting seat is fixed to the electromagnetic coil moving member 217. A receiving groove is provided in the middle of the electromagnetic coil moving member 217. The first supporting seat is fixed to the receiving groove.

[0089] Specifically, a semi-cylindrical first inner cavity is arranged on the top of the first support seat, and a semi-cylindrical second inner cavity is arranged on the bottom of the first support cover body. The first inner cavity and the second inner cavity enclose a cylindrical first accommodating cavity to accommodate the X-axis electromagnetic coil 209 or the Y-axis electromagnetic coil. The first support seat and the first support cover body are detachably connected by adjusting bolts 208. When the first support seat and the first support cover body are disassembled, it is convenient to replace or adjust the X-axis electromagnetic coil 209 or the Y-axis electromagnetic coil. When the first support seat and the first support cover body are connected together, the X-axis electromagnetic coil 209 or the Y-axis electromagnetic coil is fixed.

[0090] In this embodiment, the electromagnetic coil moving member 217 is driven to move by a moving driving member, and the moving driving member can be a linear motor, a hydraulic rod, and a pneumatic rod.

[0091] In this embodiment, Figure 6As shown, the third electromagnetic coil fixing member 215 is driven by the electromagnetic coil driving mechanism to slide in the vertical direction relative to the base box. The electromagnetic coil driving mechanism includes a screw motor and a rotating screw. The rotating screw is fixedly connected to the output shaft of the screw motor. Two third electromagnetic coil fixing members 215 are slidably connected to the rotating screw at a certain distance. Each third electromagnetic coil fixing member 215 is provided with an electromagnetic coil.

[0092] In this embodiment, the third electromagnetic coil fixing member 215 includes a second support seat and a second support cover body, a semi-cylindrical third inner cavity is arranged on the top of the second support seat, and a semi-cylindrical fourth inner cavity is arranged on the bottom of the second support cover body, and the third inner cavity and the fourth inner cavity enclose a cylindrical first accommodating cavity to accommodate the z-axis electromagnetic coil 211, and the second support seat and the second support cover body are detachably connected by fixing bolts 213. When the second support seat and the second support cover body are disassembled, it is convenient to replace or adjust the z-axis electromagnetic coil 211, and when the second support seat and the second support cover body are connected together, the z-axis electromagnetic coil 211 is fixed.

[0093] In this embodiment, the second support seat or the second support cover is slidably connected to the lead screw via a lead screw nut.

[0094] In this embodiment, Figure 6 and Figure 7 As shown, in order to prevent the third electromagnetic coil fixing member 215 from deflecting, a plurality of support rods 212 are further included. The plurality of support rods 212 are fixed on the central area, and the third electromagnetic coil fixing member 215 is slidably connected to the plurality of support rods 212 .

[0095] Specifically, in this embodiment, three support rods 212 are provided, and the three support rods 212 and the lead screw are distributed in a rectangular shape in the central area. The second support seat and the second support cover body are provided with movable holes at the four corners. The second support seat and the second support cover body are penetrated by the support rods 212 or the lead screw through the movable holes to be slidably connected with the support rods 212 or the lead screw.

[0096] In this embodiment, Fig.10 As shown, the host computer includes a PWM control module, which is used to control the movement of the lead screw motor to achieve precise adjustment of the position of the z-axis electromagnetic coil 211.

[0097] In this embodiment, Fig.10As shown, the host computer also includes a current acquisition module and a current generation module. The current generation module is used to receive parameter instructions, including the selection of magnetic field types such as circular, conical, vibration, etc., as well as commands such as frequency, amplitude, pitch angle, etc., to form a reference magnetic field or reference current of the X-axis electromagnetic coil 209, the Y-axis electromagnetic coil and / or the z-axis electromagnetic coil 211 for closed-loop control algorithm control. The sensor of the current acquisition module is powered by a single DC source, outputs a small analog signal to the acquisition card, and transmits it to the host computer for identification through USB and other communication methods, and obtains the system observation value of the closed-loop control algorithm through calculation.

[0098] In this embodiment, Fig.10 As shown, the host computer has a built-in closed-loop control algorithm module, which includes a signal preprocessing module, a Kalman filter, a Smith predictive corrector and an optimal controller.

[0099] The signal preprocessing module is used to calibrate the electromagnetic coil to obtain the current of the electromagnetic coil;

[0100] The Kalman filter is used to determine the process noise and the measurement noise of the current of the electromagnetic coil;

[0101] The Smith predictive corrector is used to delay the control process, compare and correct the estimated value obtained by the Kalman filter;

[0102] The optimal controller is used to output the optimal current of the stepper motor 303 .

[0103] Specifically, the signal preprocessing module is used to calibrate the electromagnetic coil to obtain the quantitative relationship between the voltage of each stepper motor 303 and the current of the corresponding electromagnetic coil, and obtain the current generated by the electromagnetic coil through the sensor.

[0104] The signal preprocessing module calibrates the electromagnetic coil through the current sensor to obtain the current of the electromagnetic coil. The calculation formula is:

[0105] U o =k 1 ·U+k 2 I

[0106] Among them, U o is the output voltage of the sensor chip, U is the bias voltage of the sensor chip, I is the current of the electromagnetic coil, k 1 and k 2 is the corresponding proportionality coefficient.

[0107] Signal preprocessing requires calibration of the electromagnetic coil, and the parameters that need to be determined are: the mapping relationship β between the maximum PWM voltage and the maximum electromagnetic coil current, the mapping relationship α between the electromagnetic coil current and the generated magnetic field, and the sensor bias voltage U. β is determined by the internal configuration of the current amplifier, α can be measured by a multimeter or a Gauss meter, and the bias voltage U can be determined by the corresponding weighted average algorithm or visual estimation.

[0108] The closed-loop control algorithm requires the establishment of a state feedback controller. In the case of unknown effects of various system components on input and output, adaptive control can be performed while reducing the system computational load. The system state space based on LQR is constructed as:

[0109]

[0110] Among them, j corresponds to the three axes of the electromagnetic coil system, k represents the current time step, and D j Indicates the time domain delay between the current host computer processing time and the detected current, A j , B j , C j , D j Corresponding to the parameter matrix of the system model, X j is the system state variable, b j (k) represents the magnitude of the magnetic field at the current time step, I j (k) is the current shaft current, α represents the mapping relationship between the coil current and the generated magnetic field, u j (kD j ) is the PWM voltage corresponding to the current required by the current axis to generate the magnetic field. In order to ensure the rapidity and accuracy of the system current control, the integral variable x is defined i (k), i represents the x, y, and z axes, and the state space is expanded:

[0111] x i (k) = x i (k-1)+r(k)-I j (k) = x i (k-1)+r(k)-CX j (k)-D j u j (k)

[0112]

[0113] Among them, r i (k) is the reference current, and the error matrix of the corresponding augmented system is expressed as follows, where the reference term r i (k) The difference is 0;

[0114] The augmented system is expressed as:

[0115]

[0116] The corresponding controller output parameters are:

[0117]

[0118] where S is the infinite observable solution of the discrete-time Riccati equation, [K j -K i ] is the LQR regulator gain, γ is the weighted control parameter, which can be adjusted according to the actual control requirements of the system.

[0119] The Kalman filter of the closed-loop control algorithm needs to determine the process noise and measurement noise. In order to save the system computing load, it can be determined in the calibration process of signal preprocessing. The process noise is determined in the mapping calibration of current and magnetic field, and the measurement noise can be measured simultaneously in the process of determining the sensor bias voltage. The time update process of the Kalman filter and the Kalman gain κ are:

[0120]

[0121] in, is the estimated system state value of the Kalman filter, To estimate the magnetic field value, is the estimated current value, D is the time domain delay coefficient of the system, is the ratio of the sampling frequency to the output frequency rounded up, P is the covariance matrix of the estimation error, and R v is the measurement noise matrix, A j , B j , C j , D j They correspond to the parameter matrices of the system model, k represents the current time step of the host computer cycle, α represents the mapping relationship between the coil current and the generated magnetic field, and X j (k) is the system state variable at time k, u j (kD j ) is the PWM voltage corresponding to the current required to generate the magnetic field on the current axis.

[0122] The Smith predictive corrector of the closed-loop control algorithm delays the control process and estimates the Kalman filter. The comparison was made and the correction was performed. The corresponding model and the output of the optimal controller are:

[0123]

[0124]

[0125] Among them, X p (k) and Ip (k) represents the predicted state value and the predicted current value of the Smith predictive corrector system without time delay at time step k, X pd (k) and I pd (k) represents the state prediction value and the delay-free current prediction value of the Smith predictor corrector delay system at time step k, represents the Kalman prediction value for k+1 time step based on k time step, X(k) and I(k) represent the system state value and current value of k time step for optimal controller control obtained by Smith predictive corrector part, Indicates based on u j The Kalman prediction value is calculated based on (kD) and the mapping relationship between the electromagnetic coil voltage and current β.

[0126] The closed-loop control algorithm can use composite functions to replace independent variables or sine fitting or Fourier fitting for the z-transform required for discrete time domain delay to perform approximate processing. The closed-loop control algorithm can define the state space matrix parameters A, B, C, D by itself, and use the system controllability matrix M c and the observability matrix M o To verify:

[0127]

[0128] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A mobile platform type electromagnetic control system, characterized in that: include: The basic box is provided with a plurality of stepper motors, each of which has a brush shaft sleeve on its output shaft, a horizontally arranged cross arm on the brush shaft sleeve, two brushes at both ends of the cross arm, a relay plate outside each brush, and each of which rotates to drive the two brushes to contact or not contact the corresponding two relay plates; A plurality of groups of electromagnetic coils, each group of electromagnetic coils includes two electromagnetic coils, two ends of one electromagnetic coil are electrically connected to two relay plates corresponding to a stepping motor, and two ends of another electromagnetic coil are electrically connected to two brushes corresponding to the stepping motor; The host computer controls the three stepper motors to rotate forward or reverse.

2. The mobile platform type electromagnetic manipulation system according to claim 1, characterized in that: It also includes a rotary encoder, which is fixed on the output shaft of the stepper motor, and the brush shaft sleeve is fixed on the output shaft of the rotary encoder.

3. The mobile platform type electromagnetic manipulation system according to claim 1, characterized in that: The basic box is fixed on the platform connecting device, and the platform connecting device is slidably connected to the movable platform so that the platform connecting device can slide on the movable platform.

4. The mobile platform type electromagnetic manipulation system according to claim 1, characterized in that: The electromagnetic coil is an X-axis electromagnetic coil, a Y-axis electromagnetic coil or a Z-axis electromagnetic coil, and also includes a first electromagnetic coil fixing part, a second electromagnetic coil fixing part and a third electromagnetic coil fixing part; The two X-axis electromagnetic coils are respectively arranged in two first electromagnetic coil fixing members in a one-to-one correspondence, and the two first electromagnetic coil fixing members are slidably connected to the basic box in a horizontal transverse direction to drive the two X-axis electromagnetic coils to slide in a horizontal transverse direction relative to the basic box to generate a magnetic field in the X-axis direction; The two Y-axis electromagnetic coils are respectively arranged in the other two second electromagnetic coil fixing members in a one-to-one correspondence, and the other two first electromagnetic coil fixing members are slidably connected to the basic box in a horizontal transverse direction to drive the two Y-axis electromagnetic coils to slide in a horizontal transverse direction relative to the basic box to generate a Y-axis direction magnetic field; The two Z-axis electromagnetic coils are respectively arranged in two third electromagnetic coil fixing parts in a one-to-one correspondence, and the two third electromagnetic coil fixing parts are vertically slidably connected to the basic box to drive the two Z-axis electromagnetic coils to slide vertically relative to the basic box to generate a Z-axis magnetic field.

5. The mobile platform type electromagnetic manipulation system according to claim 4, characterized in that: A central area is provided on the basic box body, and a plurality of stepper motors include an X-axis stepper motor, a Y-axis stepper motor and a Z-axis stepper motor, all of which are provided in the central area. Four sliding grooves are respectively extended outward from the four corners of the central area, and a wedge-shaped structure is formed between the sliding grooves. The first electromagnetic coil fixing part or the second electromagnetic coil fixing part is fixed to the electromagnetic coil moving part, and accommodating grooves are respectively provided on both sides of the electromagnetic coil moving part. Shoulder blocks are built in the accommodating grooves, and the shoulder blocks are elastically connected to the accommodating grooves through elastic parts. The middle part of the electromagnetic coil moving part is located on the wedge-shaped structure, and the two shoulder blocks on both sides are respectively slidably connected to the two sliding grooves in a one-to-one correspondence.

6. The mobile platform type electromagnetic manipulation system according to claim 5, characterized in that: Each of the sliding grooves is provided with an X-axis electrical outer spring sheet and a Y-axis electrical outer spring sheet on both sides close to the two wedge-shaped structures; The two relay plates corresponding to the X-axis stepper motor are electrically connected to two of the X-axis electrical outer springs, the two brushes corresponding to the X-axis stepper motor are electrically connected to the other two X-axis electrical outer springs, and both ends of the two X-axis electromagnetic coils are electrically connected to X-axis electrical inner springs, wherein the two X-axis electrical outer springs electrically connected to one X-axis electromagnetic coil can be in contact with or not in contact with the two X-axis electrical inner springs electrically connected to the two relay plates to achieve the connection and disconnection of the X-axis electromagnetic coil, and the two X-axis electrical outer springs electrically connected to the other X-axis electromagnetic coil can be in contact with or not in contact with the two X-axis electrical inner springs electrically connected to the two brushes to achieve the connection and disconnection of the X-axis electromagnetic coil; The two relay plates corresponding to the Y-axis stepper motor are electrically connected to two of the Y-axis electrical outer reeds, the two brushes corresponding to the Y-axis stepper motor are electrically connected to the other two Y-axis electrical outer reeds, and both ends of the two Y-axis electromagnetic coils are electrically connected to Y-axis electrical inner reeds, wherein the two Y-axis electrical outer reeds electrically connected to one Y-axis electromagnetic coil can contact or not contact the two Y-axis electrical inner reeds electrically connected to the two relay plates to achieve the connection and disconnection of the Y-axis electromagnetic coil, and the two Y-axis electrical outer reeds electrically connected to the other Y-axis electromagnetic coil can contact or not contact the two Y-axis electrical inner reeds electrically connected to the two brushes to achieve the connection and disconnection of the Y-axis electromagnetic coil.

7. The mobile platform type electromagnetic manipulation system according to claim 4, characterized in that: The third electromagnetic coil fixing part is driven to slide in the vertical direction relative to the base box by the electromagnetic coil driving mechanism. The electromagnetic coil driving mechanism includes a screw motor and a rotating screw. The rotating screw is fixedly connected to the output shaft of the screw motor. The two third electromagnetic coil fixing parts are slidably connected to the rotating screw at a certain distance.

8. The mobile platform type electromagnetic manipulation system according to claim 1, characterized in that: The host computer has a built-in closed-loop control algorithm module, which includes a signal preprocessing module, a Kalman filter, a Smith predictive corrector and an optimal controller. The signal preprocessing module is used to calibrate the electromagnetic coil to obtain the current of the electromagnetic coil; The Kalman filter is used to determine the process noise and the measurement noise of the current of the electromagnetic coil; The Smith predictive corrector is used to delay the control process, compare and correct the estimated value obtained by the Kalman filter; The optimal controller is used to output the optimal current of the stepper motor.

9. The mobile platform type electromagnetic manipulation system according to claim 8, characterized in that: A state feedback controller is established in the closed-loop control algorithm module, and adaptive control is performed through the state feedback controller.

10. The mobile platform type electromagnetic manipulation system according to claim 8, characterized in that: The signal preprocessing module calibrates the electromagnetic coil through the current sensor to obtain the current of the electromagnetic coil. The calculation formula is: IN o =k1·U+k2·I Among them, U o is the output voltage of the sensor chip, U is the bias voltage of the sensor chip, I is the current of the electromagnetic coil, k1 and k2 are the corresponding proportional coefficients; The Kalman filter determines the calculation formula for the process noise and measurement noise of the electromagnetic coil current: in, is the estimated system state value of the Kalman filter, To estimate the magnetic field value, is the estimated current value, D is the time domain delay coefficient of the system, is the ratio of the sampling frequency to the output frequency rounded up, P is the covariance matrix of the estimation error, and R v is the measurement noise matrix, Aj, B j , C j , D j They correspond to the parameter matrices of the system model, k represents the current time step of the host computer cycle, α represents the mapping relationship between the coil current and the generated magnetic field, and X j (k) is the system state variable at time k, u j (kD j ) is the PWM voltage corresponding to the current required by the current axis to generate a magnetic field; The Smith predictive corrector delays the control process, compares the estimated value obtained by the Kalman filter and makes corrections using the following calculation formula: Among them, X p (k) and I p (k) represents the predicted state value and the predicted current value of the Smith predictive corrector system without time delay at time step k, X pd (k) and I pd (k) represents the state prediction value of the Smith predictor corrector delay system and the delay-free current prediction value at time step k; The calculation formula for the optimal current of the optimal controller output electromagnetic coil is: in, represents the Kalman prediction value for k+1 time step based on k time step, X(k) and I(k) represent the system state value and current value of k time step for optimal controller control obtained by Smith predictive corrector part, Indicates based on u j The Kalman prediction value is calculated based on (kD) and the mapping relationship between the electromagnetic coil voltage and current β.

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