Movement control device

Abstract

The invention provides a movement control device, and the device comprises a plurality of magnet groups which are fixed at a first side edge of a movable workbench and are arranged in a non-collinear manner, and each magnet group comprises a pair of magnets with opposite polarities, so as to form a gradient magnetic field region; the Hall sensors are fixed to the second side edge of the main substrate, the second side edge of the main substrate is opposite to the first side edge of the movable workbench, and the induction face of each Hall sensor is parallel to the magnetic gradient face of the corresponding magnet set in the magnet sets; and the controller is used for receiving sensing data of the plurality of Hall sensors to form a real-time data matrix and controlling the movable workbench to move to a zero position according to the real-time data matrix. Through the technical scheme, the movable workbench can accurately move to the zero position, the manufacturing cost is reduced, and meanwhile the structure is simplified.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing technology, and in particular to a mobile control device. Background Art

[0002] In the field of semiconductor manufacturing, high-precision displacement measurement technology is the key to equipment performance. The accuracy of the workpiece stage motion control directly determines the process accuracy. At present, mainstream semiconductor equipment mostly uses laser interferometers to perform incremental displacement measurement on the worktable. Although the laser interferometer can achieve high-precision measurement at the nanometer level, it is essentially a relative measurement system and can only provide incremental displacement information. It cannot automatically restore to the same reference zero point after the equipment is turned on or the workpiece stage is moved in and out. Therefore, the absolute zero position positioning of the workpiece stage relative to the equipment is crucial. The existing technical solution sets a laser collimator and a spot position detector on the main substrate, and the reflection module is installed under the workpiece stage. The collimated light path is guided back to the detector through the corner mirror and the reflector. The spot detector records the spot position offset and converts the optical signal into an electrical signal output, thereby achieving two-dimensional or three-dimensional zero position positioning.

[0003] However, the optical system has a complex structure and contains multiple precision optical components, which increases the difficulty of manufacturing and installation. At the same time, high-precision alignment is required between the optical components, and the environmental conditions are extremely demanding. Any slight alignment deviation or environmental interference may lead to measurement errors. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a mobile control device to overcome at least one of the above-mentioned defects.

[0005] In a first aspect, the present application provides a mobile control device, comprising: a plurality of magnet groups fixed at a first side of a movable workbench and arranged in a non-collinear manner, each magnet group comprising a pair of magnets with opposite polarities to form a gradient magnetic field region; a plurality of Hall sensors fixed at a second side of a main substrate, the second side of the main substrate being opposite to the first side of the movable workbench, the sensing surface of each Hall sensor being parallel to the magnetic gradient surface of a corresponding magnet group among the plurality of magnet groups; a controller receiving sensing data from the plurality of Hall sensors to form a real-time data matrix, and controlling the movable workbench to move to a zero position according to the real-time data matrix.

[0006] In one possible embodiment, the device further includes: a plurality of magnet fixing members, an isolation structure formed in the middle of each magnet fixing member to form two identical installation spaces on each magnet fixing member for fixing a pair of magnetic poles of the magnet group, so that the gradient distribution of the gradient magnetic field region of each magnet group is symmetrical.

[0007] In a possible embodiment, the device further includes: a plurality of magnet tooling parts fixed at the first side of the movable workbench, a magnet fixing part mounting groove being formed on the top surface of each magnet tooling part and the first side surface adjacent to the top surface, each magnet fixing part mounting groove being used to fix a magnet fixing part, so that the plurality of magnet groups are arranged in a non-collinear form at the first side.

[0008] In a possible implementation, the movable workbench is capable of moving in multiple degrees of freedom, and the number of the multiple degrees of freedom is the same as the number of rows of the real-time data matrix.

[0009] In one possible embodiment, the real-time data matrix includes multiple magnetic field intensities and displacements corresponding to each magnetic field strength, the sensing data includes a voltage signal of each Hall sensor, each magnetic field strength is obtained based on the voltage signal of the corresponding Hall sensor, each displacement is obtained based on the corresponding magnetic field strength, and each displacement includes displacement components corresponding to each of the multiple degrees of freedom.

[0010] In one possible embodiment, the controller is configured to: control the movable worktable to move to a coarse zero position; receive sensing data from the multiple Hall sensors in real time to form the real-time data matrix, and determine the displacement component of the movable worktable in each degree of freedom based on the real-time data matrix; for each degree of freedom, control the movable worktable to move toward the zero position in the degree of freedom based on the displacement component corresponding to the degree of freedom; when it is determined that the difference between the displacement component in each degree of freedom of the movable worktable and the zero position is less than the corresponding preset error value, determine that the movable worktable has moved to the zero position.

[0011] In a possible embodiment, the device also includes: a plurality of sensor tooling parts, fixed on the main substrate, the first end of each sensor tooling part is fixed at the second side of the main substrate, and a cable is arranged axially on each sensor tooling part, and the first end of each sensor tooling part is formed with a first mounting groove and a second mounting groove, and the first mounting groove is used to fix the corresponding Hall sensor; a plurality of board modules, each board module is fixed in the corresponding second mounting groove, the first end of each board module is connected to the controller through the cable, and the second end of each board module is connected to the output end of the corresponding Hall sensor, for converting the output voltage of the corresponding Hall sensor into a voltage signal.

[0012] In one possible embodiment, each board module includes a differential circuit, which includes a filtering unit and an output unit. The filtering unit is used to receive the output voltage of the Hall sensor and perform filtering processing. The output unit is used to output the voltage signal. The first end of the filtering unit is connected to the power supply, the second end of the filtering unit is connected to the corresponding Hall sensor, the third end of the filtering unit is connected to the first end of the output unit, and the second end of the output unit is used to output the voltage signal.

[0013] In a possible implementation, the filtering unit includes a first capacitor, a diode, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and a second capacitor, wherein the first end of the third resistor is connected to the Hall sensor, the second end of the third resistor is connected to the first end of the fifth resistor, the second end of the fifth resistor is connected to a power supply, the first end of the fourth resistor is connected to the Hall sensor, the second end of the fourth resistor is connected to the first end of the sixth resistor, the second end of the sixth resistor is grounded, the cathode of the diode is connected between the third resistor and the fifth resistor, the anode of the diode is grounded, the first end of the first resistor is connected to the anode of the diode, the second end of the first resistor is connected to the Hall sensor, the first end of the second resistor is connected to the cathode of the diode, the second end of the second resistor is grounded, the first end of the first capacitor is connected to the second end of the fifth resistor, the second end of the first capacitor is connected to the second end of the sixth resistor, the first end of the second capacitor is connected to the Hall sensor, and the second end of the second capacitor is grounded.

[0014] In one possible implementation, the output unit includes a first operational amplifier, a second operational amplifier, a seventh resistor, an eighth resistor, and a ninth resistor, wherein the non-inverting input of the first operational amplifier is connected to the Hall sensor, the inverting input of the first operational amplifier is connected to the inverting input of the second operational amplifier through the seventh resistor, the non-inverting input of the second operational amplifier is connected to the Hall sensor, the first end of the eighth resistor is connected to the inverting input of the first operational amplifier, the second end of the eighth resistor is connected to the output of the first operational amplifier, the first end of the ninth resistor is connected to the inverting input of the second operational amplifier, and the second end of the ninth resistor is connected to the output of the second operational amplifier.

[0015] The beneficial effects of the mobile control device of the present application are as follows: The present application positions the movable workbench through a Hall sensor and a magnet group, so that the movable workbench can be accurately moved to the zero position and is insensitive to environmental factors, thereby reducing manufacturing costs and simplifying the structure.

[0016] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A schematic structural diagram of a mobile control device provided in an embodiment of the present application; Figure 2 A schematic structural diagram of a magnet assembly provided in an embodiment of the present application; Figure 3 A schematic diagram of the structure of the sensor tooling provided in an embodiment of the present application; Figure 4 A schematic diagram of the Hall effect principle provided in an embodiment of the present application; Figure 5 A schematic diagram of the gradient magnetic field region provided in an embodiment of the present application; Figure 6 A schematic diagram of the relationship between the output voltage and displacement of the Hall sensor provided in an embodiment of the present application; Figure 7 A schematic diagram of the structure of a differential circuit provided in an embodiment of the present application; Figure 8 A schematic diagram of the structure of the signal link provided in the embodiment of the present application; Figure 9 This is a flow chart of the movement control method provided in an embodiment of the present application.

[0019] Reference numerals: 11 - magnet fixture; 12 - magnet group; 121 - magnetic pole; 122 - magnet fixing member; 21 - Hall sensor; 22 - sensor fixture; 23 - board module. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application for which protection is claimed, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, each other embodiment obtained by those skilled in the art without making creative work falls within the scope of protection of the present application.

[0021] First, the application scenarios to which this application is applicable are introduced. This application can be applied to semiconductor manufacturing.

[0022] In semiconductor manufacturing, high-precision displacement measurement technology is key to ensuring equipment performance. The accuracy of the workpiece stage's motion control directly determines process precision, making precise measurement and control of the workpiece stage's position crucial. Currently, mainstream semiconductor equipment mostly uses laser interferometers for incremental displacement measurement. While laser interferometers can achieve high-precision measurements at the nanometer level, they are essentially relative measurement systems that only provide incremental displacement information and cannot automatically restore to the same reference zero point after the equipment is turned on or the workpiece stage is moved in or out. Therefore, absolute zero positioning of the workpiece stage relative to the equipment is particularly important.

[0023] Chinese patent application number CN102455169B adopts an optical sensor solution, which sets a laser collimator and a light spot position detector on the main substrate. The reflection module is installed under the workpiece table, and the collimated light path is guided back to the detector through the corner mirror and the reflector. The light spot detector records the light spot position offset and converts the optical signal into an electrical signal output, thereby achieving two-dimensional or three-dimensional zero-position positioning. However, the optical system has a complex structure and contains multiple precision optical elements. It requires precise optical alignment, which increases the difficulty of manufacturing and installation. In addition, the optical system is sensitive to environmental factors. Dust, vibration and ambient light in the light path may cause measurement errors. In addition, the optical elements are easily affected by temperature and have high requirements for temperature stability. At the same time, the price of light sources and precision optical elements is relatively expensive, resulting in a high cost of this solution.

[0024] Based on this, an embodiment of the present application provides a mobile control device, which aims to position a movable workbench through a Hall sensor and a magnet group, so that the movable workbench can be accurately moved to the zero position, and is insensitive to environmental factors, thereby reducing manufacturing costs and simplifying the structure.

[0025] See also Figure 1 , Figure 1 This is a schematic diagram of the structure of the mobile control device provided in the embodiment of the present application. Figure 1 As shown in , the mobile control device provided in the embodiment of the present application includes: multiple magnet groups 12, multiple magnet fixing parts 122, multiple magnet tooling parts 11, multiple Hall sensors 21, multiple sensor tooling parts 22, multiple board modules 23 and a controller.

[0026] Here, a plurality of magnet groups 12 are fixed at a first side of the movable workbench and arranged in a non-collinear manner. Each magnet group 12 includes a pair of magnetic poles 121 with opposite polarities to form a gradient magnetic field region.

[0027] Specifically, multiple magnet groups 12 provide signal sources for the entire mobile control device. Each magnet group 12 is fixed in a corresponding magnet fixing member 122. An isolation structure is formed in the middle of each magnet fixing member 122, so that two identical spaces are formed on each magnet fixing member 122 to fix a pair of magnetic poles 121 in the magnet group 12, so that the gradient distribution of the gradient magnetic field area of ​​each magnet group 12 is symmetrical.

[0028] Multiple magnet fixing parts 122 are respectively fixed on corresponding magnet tooling parts 11, and multiple magnet tooling parts 11 are fixed at the first side of the movable workbench. A magnet fixing part 122 mounting groove is respectively formed on the top surface and the first side surface adjacent to the top surface of each magnet tooling part 11. Each magnet fixing part 122 mounting groove is used to fix a magnet fixing part 122, so that multiple magnet groups 12 are arranged in a non-collinear form at the first side and can move with the movable worktable.

[0029] As an example, the magnet group 12 of the present application uses a pair of high-stability permanent magnets to generate a magnetic field with moderate strength and uniform distribution. Each magnet group 12 uses a pair of samarium cobalt magnets with a magnetic strength of about 1050mT and high stability. Figure 2 As shown, Figure 2 This is a schematic diagram of the structure of the magnet group 12 provided in an embodiment of the present application. Each magnet group 12 is bonded and fixed to the magnet fixing member 122 in a polarity-reversed symmetrical layout (one magnet with the S pole facing upward and the other magnet with the S pole facing downward). The isolation structure formed in the middle of the magnet fixing member 122 ensures that the distance between the two magnetic poles 121 is 2 mm. The installation accuracy of the magnet group 12 is ≤10μm, ensuring the symmetry of the magnetic field gradient distribution.

[0030] Multiple Hall sensors 21 are fixed on the second side of the main substrate. The main substrate is fixed. The second side of the main substrate is opposite to the first side of the movable workbench. The sensing surface of each Hall sensor 21 is parallel to the magnetic gradient surface of a corresponding magnet group 12 among the multiple magnet groups 12.

[0031] Specifically, each magnet group 12, through its unique magnetic field spatial distribution characteristics, can enable the Hall sensor 21 to obtain the best response curve within the working area. The layout positions of multiple magnet groups 12 are precisely calculated to ensure that the Hall sensor 21 obtains the best detection sensitivity and positioning accuracy. Multiple magnet groups 12 provide a long-term stable magnetic field source with a low temperature coefficient characteristic, ensuring the reliable operation of the device under various environmental conditions, and providing a stable and reliable signal source for achieving the absolute position zero return of the movable workpiece stage.

[0032] like Figure 3 As shown, Figure 3 This is a structural schematic diagram of the sensor tooling 22 provided in an embodiment of the present application, where each Hall sensor 21 is installed in the first mounting slot of the corresponding sensor tooling 22. The sensor tooling 22 is responsible for providing a stable and flat fixing surface for the Hall sensor 21, so that the sensing surface of the Hall sensor 21 is parallel to the magnetic gradient surface of the corresponding magnet group 12, and the vertical spacing between the magnetic gradient surface of each magnet group 12 and the corresponding Hall sensor 21 is approximately 1.5mm~2.2mm, thereby avoiding positioning errors caused by installation errors of the Hall sensor 21. Each Hall sensor 21 is responsible for sensing the magnetic field changes generated by the corresponding magnet group 12 on the movable workpiece table as the movable workpiece table moves, and converting the magnetic field changes into output voltage.

[0033] The controller is used to receive sensing data from a plurality of Hall sensors 21 to form a real-time data matrix, and control the movable workbench to move to a zero position according to the real-time data matrix.

[0034] Specifically, if Figure 4 As shown, Figure 4 This is a schematic diagram of the Hall effect principle provided in the embodiment of the present application. The Hall effect sensor 21 works based on the Hall effect principle. When a current I is passed through a metal or semiconductor material (i.e., a Hall element having a length l, a width w, and a thickness t), the current I x When the current is applied perpendicularly to the direction of the current, the carriers (such as free electrons with a charge of -q) migrate in a specific direction at an average drift velocity v driven by the electric field. z , the electrons will be deflected by the Lorentz force, resulting in an asymmetric distribution of charge at the lateral interface of the Hall element, thereby forming a transverse electric field that is dynamically balanced with the Lorentz force, and ultimately leading to a measurable Hall voltage V on both sides of the Hall element. h The amplitude of the Hall voltage is determined by the input current, magnetic induction intensity, and the intrinsic properties of the material (such as carrier concentration and mobility). Its mathematical expression is:

[0035] Among them, V h is the voltage across the Hall element, Rh is the Hall constant, I x is the current value passing through the Hall element, and t is the thickness of the Hall element.

[0036] The present application symmetrically arranges a pair of permanent magnets with opposite polarities (NS pole pairs), namely magnet groups 12, and forms a Figure 5 The gradient magnetic field region shown in the figure, a, b, c represent the three positions of the Hall sensor 21, respectively. According to the magnetic field superposition principle, the magnetic field intensity B includes the vertical component B z and the vertical component B x , vertical component B z (x) changes linearly along the x-axis, satisfying the following relationship:

[0037] Where k is the magnetic field gradient coefficient and x is the displacement.

[0038] Combined with the Hall effect formula, the output voltage V of the Hall sensor 21 is out is proportional to the displacement x Figure 6 The linear proportional relationship shown corresponds to the mathematical relationship:

[0039] Where S is the system sensitivity.

[0040] In a preferred example of the present application, since multiple Hall sensors 21 are far away from the controller and voltage signals need to be transmitted through long cables, the present application uses a board module 23 to condition the output voltage. Each board module 23 includes a differential circuit to reduce the sensitivity of the signal near the zero point to power supply fluctuations and suppress the common-mode noise introduced by the long cable.

[0041] Specifically, the function of the board module 23 is to power the Hall sensor 21 through the diode Z1. In addition, because the signal output by the Hall sensor 21 is extremely weak, usually only at the millivolt level, and needs to be transmitted through a long cable, the board module 23 is required to amplify the signal output by the Hall sensor 21.

[0042] First, the weak signal output by the Hall effect sensor 21 is typically only a few millivolts, making it highly susceptible to external electromagnetic interference, thermal noise, and various coupling interferences. Without signal amplification, the ADC acquisition board will struggle to capture the valid signal, resulting in distorted measurement data. By integrating a differential circuit at the front end of the signal, the signal amplitude can be significantly increased, thereby improving the signal-to-noise ratio and ensuring the system's anti-interference capability and measurement accuracy.

[0043] Secondly, the signal output by Hall sensor 21 can introduce significant common-mode interference during transmission over long cables, such as power-frequency noise, ground potential differences, and high-frequency interference. However, a differential circuit, with its common-mode rejection ratio (CMRR), effectively filters out the common-mode portion of the input signal, amplifying only the true differential signal output by the sensor. Therefore, using a differential circuit is an effective solution to address interference issues associated with long cable transmission. Furthermore, amplifying the signal to a ±5V range matches the input range of the ADC acquisition board. For example, a 12-bit ADC with a ±5V input range can achieve a resolution of 2.44mV. If the signal is directly input without amplification, the ADC's effective number of bits will be significantly reduced, resulting in increased quantization error and reduced measurement accuracy. Signal amplification fully utilizes the ADC's dynamic range, thereby improving the system's measurement accuracy.

[0044] Finally, the small signal output by Hall effect sensor 21 is susceptible to interference from cable voltage drop, capacitive coupling, and crosstalk during long-distance transmission. Amplified signals, however, are more stable in the face of these interferences, effectively reducing transmission errors. Therefore, high-quality amplification at the signal source is a crucial engineering practice for ensuring signal transmission quality.

[0045] The structural diagram of the differential circuit is as follows Figure 7 As shown, this application uses GaAs gallium arsenide Hall sensor 21 such as KSY44 or HG-302C, which has no built-in amplifier and the output voltage is in the millivolt level, so a differential circuit is required to customize the gain and magnetic field range. Its noise is mainly 1 / f noise, which can be suppressed by limiting the bandwidth.

[0046] Specifically, the differential circuit includes a filtering unit and an output unit. The filtering unit is used to receive the output voltage of the Hall sensor 21 and perform filtering processing. The output unit is used to output a voltage signal.

[0047] The first end of the filter unit is connected to the power supply, the second end of the filter unit is connected to the corresponding Hall sensor 21, the third end of the filter unit is connected to the first end of the output unit, and the second end of the output unit is used to output a voltage signal.

[0048] Furthermore, the filtering unit includes a first capacitor C1, a diode Z1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a second capacitor C2, wherein a first end of the third resistor R3 is connected to the Hall sensor 21, a second end of the third resistor R3 is connected to a first end of the fifth resistor R5, a second end of the fifth resistor R5 is connected to a power supply, a first end of the fourth resistor R4 is connected to the Hall sensor 21, a second end of the fourth resistor R4 is connected to a first end of the sixth resistor R6, a second end of the sixth resistor R6 is grounded, a cathode of the diode Z1 is connected between the third resistor R3 and the fifth resistor R5, an anode of the diode Z1 is grounded, a first end of the first resistor R1 is connected to the anode of the diode Z1, a second end of the first resistor R1 is connected to the Hall sensor 21, a first end of the second resistor R2 is connected to the cathode of the diode Z1, a second end of the second resistor R2 is grounded, a first end of the first capacitor C1 is connected to a second end of the fifth resistor R5, a second end of the first capacitor C1 is connected to a second end of the sixth resistor R6, a first end of the second capacitor C2 is connected to the Hall sensor 21, and a second end of the second capacitor C2 is grounded.

[0049] The output unit includes a first operational amplifier A1, a second operational amplifier A2, a seventh resistor R7, an eighth resistor R8 and a ninth resistor R9, wherein the non-inverting input terminal of the first operational amplifier A1 is connected to the Hall sensor 21, the inverting input terminal of the first operational amplifier A1 is connected to the inverting input terminal of the second operational amplifier A2 through the seventh resistor R7, the non-inverting input terminal of the second operational amplifier A2 is connected to the Hall sensor 21, the first end of the eighth resistor R8 is connected to the inverting input terminal of the first operational amplifier A1, the second end of the eighth resistor R8 is connected to the output terminal of the first operational amplifier A1, the first end of the ninth resistor R9 is connected to the inverting input terminal of the second operational amplifier A2, and the second end of the ninth resistor R9 is connected to the output terminal of the second operational amplifier A2.

[0050] In order to reduce the power consumption of the mobile control device and avoid the uneven expansion of the micro-ceramic glass and deformation of the reflective mirror caused by the temperature offset of the movable workpiece stage, thereby avoiding the positioning error and performance loss of the interferometer due to the change of the refractive index of the optical path, the present application uses a 2.5V precision micro-power parallel voltage reference and a third resistor R3 and a fourth resistor R4 to set the operating current of the Hall sensor 21 to 1mA, and uses two LT1358 low-power high-speed operational amplifiers, namely the first operational amplifier A1, the second operational amplifier A2, and the seventh resistor R4, the eighth resistor R5 and the ninth resistor R5 to form a differential output circuit. The common-mode voltage of 2.5V is set at the non-inverting input terminal of each operational amplifier. At this time, the differential circuit has the following at the P terminal, that is, the output terminal of the first operational amplifier A1:

[0051] Then we have:

[0052] The differential circuit has the following output at the N-terminal, which is the output of the second operational amplifier A2:

[0053] but:

[0054] Then the output voltage is:

[0055] Among them, V P is the output voltage at the P terminal, V N is the output voltage of the N terminal, V out is the output voltage of the Hall sensor 21, V cm is the common-mode voltage.

[0056] Specifically, KSY 44 and HG-302C can be equivalent to a resistance bridge. When there is no external magnetic field, the single-ended output voltage of the differential circuit should be 2.5V. Due to the internal resistance tolerance of the Hall sensor 21 (KSY 44 model, when B z =0, the input resistance is 600~900Ω; for HG-302C model, when B z =0, the input resistance is 650~850Ω) and the Hall sensor 21 has a ±20% gain tolerance R h Therefore, the present application sets a first resistor R1 and a second resistor R2 to adjust the differential output to zero.

[0057] The conditioned output voltages of the Hall sensors 21 are transmitted to the acquisition board through cables, which convert the analog signals into digital signals and then send them to the controller for real-time signal processing to form a signal chain. The structural diagram of the signal chain is shown in FIG. Figure 8 The controller performs sliding average filtering on the digital signal and smoothes the output voltage with a 10-point sliding window, effectively suppressing random noise and short-term fluctuations and improving signal stability.

[0058] In a preferred example of the present application, the movable workbench is capable of moving in multiple degrees of freedom, the number of the multiple degrees of freedom is the same as the number of the multiple magnet groups 12, the number of the multiple degrees of freedom is the same as the number of rows of the real-time data matrix, the real-time data matrix includes multiple magnetic field intensities and displacements corresponding to each magnetic field strength, the sensing data includes the voltage signal of each Hall sensor 21, each magnetic field strength is obtained according to the voltage signal of the corresponding Hall sensor 21, each displacement is obtained according to the corresponding magnetic field strength, each displacement includes displacement components corresponding to each of the multiple degrees of freedom, and the controller controls the movable workbench to move to the zero position according to the displacement component of each degree of freedom.

[0059] The following three degrees of freedom (X axis translation T x , Y-axis translation T y , rotate θ around the Z axis z ) is used as an example to introduce the specific process of controlling the movable workbench to move to the zero position.

[0060] Specifically, during the in-and-out operation of the movable workpiece stage, its movement is restricted to a two-dimensional plane, namely, the XY plane, and the position of the movable workpiece stage only includes three degrees of freedom (X-axis translation, T x , Y-axis translation T y , rotate θ around the Z axis z ), so three non-collinear measurement points are required to fully constrain all degrees of freedom. That is, three magnet groups 12 are required, and three Hall sensors 21 are arranged on the main substrate. According to the above principle, three magnetic field intensities and corresponding three displacements are obtained. Each displacement includes the displacement components corresponding to the three degrees of freedom, so as to establish the following data matrix:

[0061] Among them, B i is the magnetic field strength measured by the i-th Hall sensor 21, i is the number of Hall sensors 21, and f i is the magnetic field distribution function, T x is the displacement component under the X axis, T y is the displacement component under the Y axis, θ z is the rotation component under the Z axis. By solving the data matrix, the displacement component of the movable workpiece stage relative to the zero position in each degree of freedom can be uniquely determined.

[0062] Below through Figure 9 This paper introduces the specific process of controlling the movable worktable to move to the zero position.

[0063] S101, controlling the movable workbench to move to the coarse zero position.

[0064] Here, the coarse zero is located near the zero position.

[0065] As an example, the distance between the coarse zero position and the zero position may be between (-0.1 mm to 0.1 mm) in the horizontal X direction and (-0.1 mm to 0.1 mm) in the horizontal Y direction.

[0066] S102 , receiving sensing data from a plurality of Hall sensors 21 in real time to form a real-time data matrix, and determining a displacement component of the movable worktable in each degree of freedom according to the real-time data matrix.

[0067] S103 . For each degree of freedom, according to the displacement component corresponding to the degree of freedom, control the movable workbench to move toward the zero position in the degree of freedom.

[0068] S104 : When it is determined that the difference between the displacement component of each degree of freedom of the movable worktable and the zero position is less than the corresponding preset error value, it is determined that the movable worktable has moved to the zero position.

[0069] Here, the corresponding preset errors under the three degrees of freedom are X-axis <2μm, Y-axis <4μm, and rotation θ z <6μrad. It should be noted that if the displacement component in any degree of freedom is greater than the corresponding preset error, the controller calculates the displacement component based on the difference between the real-time data matrix and the zero position, and then controls the movable workpiece stage to move again. The iterative search is repeated until the displacement component of each degree of freedom is less than the corresponding preset error or the timeout occurs.

[0070] Compared with the existing technology, this application has the following advantages: Compared with the optical system positioning and measuring device in the prior art, the present application simplifies the device structure and greatly reduces the structural complexity. The Hall sensor and the magnet are fixed by bonding, and no beam collimation or reflector angle calibration is required. The installation time is greatly reduced, the mechanical tooling does not require high-precision optical processing, and it is insensitive to environmental factors and has a wide range of applications.

[0071] In addition, the device of this application has been verified through actual measurements and has a high signal-to-noise ratio, strong anti-interference ability, a resolution of up to 1μm, a linearity error of 4.4% in the worst case, a maximum deviation of 5.6μm in the full stroke (±1.1mm), and a total power consumption of a single Hall sensor and the board card of only 35mW.

[0072] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0073] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0074] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0075] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0076] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program code, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0077] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The scope of protection of the present application is not limited thereto. Although the present application has been described in detail with reference to the above-mentioned embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-mentioned embodiments within the technical scope disclosed in the present application, or perform equivalent replacements for some of the technical features thereof. These modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A mobile control device, characterized in that: The device comprises: A plurality of magnet groups are fixed to a first side of the movable workbench and arranged in a non-collinear manner, each magnet group including a pair of magnets with opposite polarities to form a gradient magnetic field region; a plurality of Hall sensors fixed at a second side edge of the main substrate, the second side edge of the main substrate being opposite to the first side edge of the movable worktable, the sensing surface of each Hall sensor being parallel to the magnetic gradient surface of a corresponding magnet group among the plurality of magnet groups; The controller receives sensing data from the plurality of Hall sensors to form a real-time data matrix, and controls the movable workbench to move to a zero position according to the real-time data matrix.

2. The device according to claim 1, characterized in that The device further comprises: Multiple magnet fixing parts, each of which has an isolation structure formed in the middle to form two identical installation spaces on each magnet fixing part for fixing a pair of magnetic poles of the magnet group, so that the gradient distribution of the gradient magnetic field area of ​​each magnet group is symmetrical.

3. The device according to claim 2, characterized in that The device further comprises: A plurality of magnet tooling parts are fixed at the first side of the movable workbench, and a magnet fixing part mounting groove is respectively formed on the top surface and the first side surface adjacent to the top surface of each magnet tooling part, and each magnet fixing part mounting groove is used to fix a magnet fixing part, so that the plurality of magnet groups are arranged in a non-collinear form at the first side.

4. The device according to claim 1, characterized in that The movable stage is capable of moving in a plurality of degrees of freedom, the number of which is the same as the number of rows of the real-time data matrix.

5. The device according to claim 4, characterized in that The real-time data matrix includes multiple magnetic field intensities and displacements corresponding to each magnetic field intensity. The sensing data includes a voltage signal of each Hall sensor. Each magnetic field intensity is obtained based on the voltage signal of the corresponding Hall sensor. Each displacement is obtained based on the corresponding magnetic field intensity. Each displacement includes displacement components corresponding to each of the multiple degrees of freedom.

6. The device according to claim 5, characterized in that The controller is configured to: Controlling the movable workbench to move to a rough zero position; receiving sensing data from the plurality of Hall sensors in real time to form the real-time data matrix, and determining a displacement component of the movable worktable in each degree of freedom according to the real-time data matrix; For each degree of freedom, according to the displacement component corresponding to the degree of freedom, controlling the movable worktable to move toward the zero position under the degree of freedom; When it is determined that the difference between the displacement component of each degree of freedom of the movable worktable and the zero position is less than the corresponding preset error value, it is determined that the movable worktable has moved to the zero position.

7. The device according to claim 1, characterized in that The device further comprises: A plurality of sensor tooling pieces are fixed to the main substrate, wherein the first end of each sensor tooling piece is fixed to the second side edge of the main substrate, a cable is provided in the axial direction of each sensor tooling piece, and a first mounting groove and a second mounting groove are formed at the first end of each sensor tooling piece, wherein the first mounting groove is used to fix the corresponding Hall sensor; Multiple board modules, each board module is fixed in the corresponding second installation slot, the first end of each board module is connected to the controller through the cable, and the second end of each board module is connected to the output end of the corresponding Hall sensor, for converting the output voltage of the corresponding Hall sensor into a voltage signal.

8. The device according to claim 7, characterized in that Each board module includes a differential circuit, which includes a filtering unit and an output unit. The filtering unit is used to receive the output voltage of the Hall sensor and perform filtering processing, and the output unit is used to output the voltage signal. The first end of the filter unit is connected to the power supply, the second end of the filter unit is connected to the corresponding Hall sensor, the third end of the filter unit is connected to the first end of the output unit, and the second end of the output unit is used to output a voltage signal.

9. The device according to claim 8, characterized in that The filtering unit includes a first capacitor, a diode, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and a second capacitor. Wherein, a first end of the third resistor is connected to the Hall sensor, a second end of the third resistor is connected to a first end of the fifth resistor, a second end of the fifth resistor is connected to a power supply, a first end of the fourth resistor is connected to the Hall sensor, a second end of the fourth resistor is connected to a first end of the sixth resistor, and a second end of the sixth resistor is grounded. The cathode of the diode is connected between the third resistor and the fifth resistor, the anode of the diode is grounded, the first end of the first resistor is connected to the anode of the diode, the second end of the first resistor is connected to the Hall sensor, the first end of the second resistor is connected to the cathode of the diode, and the second end of the second resistor is grounded. The first end of the first capacitor is connected to the second end of the fifth resistor, the second end of the first capacitor is connected to the second end of the sixth resistor, the first end of the second capacitor is connected to the Hall sensor, and the second end of the second capacitor is grounded.

10. The device according to claim 8, characterized in that The output unit includes a first operational amplifier, a second operational amplifier, a seventh resistor, an eighth resistor and a ninth resistor, The non-inverting input terminal of the first operational amplifier is connected to the Hall sensor, the inverting input terminal of the first operational amplifier is connected to the inverting input terminal of the second operational amplifier through the seventh resistor, and the non-inverting input terminal of the second operational amplifier is connected to the Hall sensor. The first end of the eighth resistor is connected to the inverting input terminal of the first operational amplifier, the second end of the eighth resistor is connected to the output terminal of the first operational amplifier, the first end of the ninth resistor is connected to the inverting input terminal of the second operational amplifier, and the second end of the ninth resistor is connected to the output terminal of the second operational amplifier.

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