A linear motor rotor position detection method based on magnetic induction principle

Abstract

The present invention relates to a method for detecting the position of a linear motor rotor based on the principle of magnetic induction. The method comprises a stator assembly, a rotor induction head, an MCU control chip, a drive circuit, a power drive circuit, a filter / buffer circuit, and an amplifier circuit. The stator assembly comprises a linear stator module and an arc-shaped stator module connected in sequence. The linear stator module and the arc-shaped stator module are both provided with a stator coil group, a transmitting coil group, and a receiving coil group. When the rotor induction head moves on the stator assembly, the receiving magnetic field of the receiving coil group changes. The MCU control chip samples the total magnetic field induced voltage and the logic voltage of each stator module position, and calculates and obtains a control signal, which is transmitted to the control stator coil group through the power drive circuit, thereby driving the rotor induction head to move. The method of the present invention has good manufacturing consistency and high PCB coil processing accuracy. No permanent magnetic head is required, which greatly reduces system cost and has high consistency.

Description

Technical Field

[0001] The present invention belongs to the technical field of motion control positioning methods, and more specifically, relates to a method for detecting the position of a linear motor mover based on the magnetic induction principle. Background Art

[0002] As manufacturing technology evolves toward high productivity and high precision, the research of precision motion control technology is becoming increasingly important. Consequently, the demand for motion positioning control systems is also growing. These systems are widely used in industries such as automated production lines, packaging and transportation, assembly automation, and screen printing, offering higher speeds and greater processing flexibility. Traditional drive systems utilize rotary motor drive structures, and the transmission system components commonly used in traditional rotary motor transmissions, such as gear heads, shafts, keys, sprockets, chains, and belts, are very complex and bulky. Linear motors utilize a moving magnetic field to directly drive moving parts, reducing structural complexity, costs, and offering advantages such as increased speed due to reduced inertia, compliance, damping, friction, and wear.

[0003] There are two solutions for detecting the position of the mover of a linear motor in the existing technology: using a grating ruler or a Hall position sensor. The grating ruler solution mainly uses the changes in light after passing through the grating ruler to reflect the changes in displacement; the Hall position sensor solution mainly forms a Hall array: using the changes in the magnetic field and decoding the magnetic field strength, the array Hall requires FPGA for fast decoding. The above two solutions have certain disadvantages: for example, the cost of the grating ruler is high, and the manufacturing consistency of the Hall array is not high, especially reflected in the consistency of magnetization and the consistency of Hall position. In addition, the accuracy of the Hall position sensor solution depends on the calibration accuracy of each unit, and the FPGA decoding cost is high. Summary of the Invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a linear motor mover position detection method based on the magnetic induction principle, which has low cost and high reliability.

[0005] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0006] A method for detecting the position of a linear motor mover based on the principle of magnetic induction includes a stator assembly, a mover induction head, an MCU control chip, a drive circuit, a power drive circuit, a filter / buffer circuit, and an amplifier circuit. The stator assembly includes a linear stator module and an arc-shaped stator module connected in sequence. The linear stator module and the arc-shaped stator module are both provided with a stator coil group, a transmitting coil group, and a receiving coil group. When the mover induction head moves on the stator assembly, the receiving magnetic field of the receiving coil group changes. The MCU control chip samples the total magnetic field induced voltage and the logic voltage of each stator module position through the filter / buffer circuit and the amplifier circuit, and calculates and obtains a control signal. The control signal is transmitted to the control stator coil group through the power drive circuit, thereby driving the mover induction head to move. At the same time, the MCU control chip also provides a control signal to the transmitting coil group through the drive circuit.

[0007] The steps for detecting the position of the mover sensor head are as follows:

[0008] Step 1: Power on and initialize;

[0009] Step 2: The MCU control chip reads the digital IO level status;

[0010] Step 3: The MCU control chip determines the absolute position of the mover sensor head according to the coding table;

[0011] Step 4: MCU controls the chip to read the ADC value;

[0012] Step 5: Decode to obtain the relative position of the mover sensor head;

[0013] Step 6: Update the position information of the mover sensor head;

[0014] By repeating steps 2 to 5 continuously, the position information of the mover sensor head can be updated in real time.

[0015] As a preferred solution: it also includes a comparison circuit, the IO port of the MCU control chip collects information through the comparison circuit, and determines the initial position information of the linear stator module or the arc stator module where the mover sensing head is located through the absolute position decoding table built into the MCU control chip.

[0016] As a preferred solution, the transmitting coil groups are sequentially connected in series and connected to the drive circuit, and the coil winding directions of the transmitting coil groups are consistent; the receiving coil groups are sequentially connected in series, and the coil winding directions of adjacent receiving coil groups are opposite.

[0017] As a preferred solution, the transmitting coil groups are connected in parallel to the drive circuit, and the coil winding directions of the transmitting coil groups are consistent; the receiving coil groups are connected in series in sequence, and the coil winding directions of adjacent receiving coil groups are opposite.

[0018] As a preferred solution, the receiving coil assembly includes at least two layers of coil units stacked on top of each other, and the phase difference between the two layers of coil units is 90°.

[0019] As a preferred solution: the mover induction head is made of magnetic conductive material.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] In the method of the present invention, the mover of the linear motor is made of conductive material, the transmitting coil generates an alternating magnetic field, the alternating magnetic field generates eddy currents inside the mover induction shield, weakening the receiving magnetic field of the receiving coil, and then the total magnetic field induced voltage and the logic voltage of each position are sampled, and finally the mover position is calculated by the MCU control chip.

[0022] The method of the present invention has good manufacturing consistency and high PCB coil processing accuracy; and does not require a permanent magnetic head, greatly reducing system costs and having high consistency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings in the specification, which constitute a part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute a limitation on this application.

[0024] Figure 1 It is a system structure block diagram of the present invention;

[0025] Figure 2 Schematic diagram of the arrangement of the transmitting coil and the receiving coil of the present invention;

[0026] Figure 3 This is a schematic diagram of the waveform of the analog signal output by the coil of the present invention;

[0027] Figure 4 Schematic diagram of the process of the present invention;

[0028] Figure 5 This is a schematic diagram of the IO signal waveform collected by the MCU control chip of the present invention;

[0029] Figure 6 is the absolute position decoding table of the method of the present invention;

[0030] Figure 7 This is a schematic diagram of the connection structure of a transmitting coil group and a receiving coil group of the present invention;

[0031] Figure 8 The figure is a schematic diagram of the connection structure of another transmitting coil assembly and a receiving coil assembly according to the present invention. DETAILED DESCRIPTION

[0032] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0033] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0034] In addition, in the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more, unless otherwise explicitly specified.

[0036] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0037] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0038] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0039] like Figures 1 to 8 A linear motor mover position detection method based on the magnetic induction principle is shown, including a stator assembly, a mover induction head, an MCU control chip, a comparison circuit, a drive circuit, a power drive circuit, a filter / buffer circuit, and an amplifier circuit. The stator assembly includes a linear stator module and an arc-shaped stator module connected in sequence. The linear stator module and the arc-shaped stator module are both provided with a stator coil group, a transmitting coil group, and a receiving coil group. The mover induction head is made of magnetic conductive material. When the mover induction head moves on the stator assembly, the receiving magnetic field of the receiving coil group changes. The MCU control chip samples the total magnetic field induced voltage and the logic voltage of each stator module position through the filter / buffer circuit and the amplifier circuit, and calculates the position of the mover induction head. The control signal is calculated based on the position information and transmitted to the control stator coil group through the power drive circuit, thereby driving the mover induction head to move. At the same time, the MCU control chip also provides a control signal to the transmitting coil group through the drive circuit.

[0040] The IO port of the MCU control chip collects information through a comparison circuit, and determines the initial position information of the linear stator module or the arc stator module where the mover sensing head is located through the absolute position decoding table built into the MCU control chip.

[0041] The receiving coil assembly comprises at least two layers of coil units stacked on top of each other, with the two layers of coil units 90 degrees out of phase. The transmitting coil assemblies are connected in series and connected to a drive circuit, with the coils of the transmitting coil assemblies having the same winding direction. The receiving coil assemblies are connected in series, with the coils of adjacent receiving coil assemblies having opposite winding directions.

[0042] In other embodiments, the transmitting coil groups may also be connected in parallel to the driving circuit, with the coils of the transmitting coil groups having the same winding direction; the receiving coil groups may be connected in series, with the coils of adjacent receiving coil groups having opposite winding directions.

[0043] The steps for detecting the position of the mover sensor head are as follows:

[0044] Step 1: Power on and initialize;

[0045] Step 2: The MCU control chip reads the digital IO level status;

[0046] Step 3: The MCU control chip determines the absolute position of the mover sensor head according to the coding table;

[0047] Step 4: MCU controls the chip to read the ADC value;

[0048] Step 5: Decode to obtain the relative position of the mover sensor head;

[0049] Step 6: Update the position information of the mover sensor head;

[0050] By repeating steps 2 to 5 continuously, the position information of the mover sensor head can be updated in real time.

[0051] The following uses 10 coils as an example to explain in detail the changes in the signals collected by the MCU control chip when the actuator does not enter the coil sensing area and when it enters the corresponding coil sensing area:

[0052] 1. When no mover enters the coil induction area:

[0053] Coils 1, 3, 5, 7, and 9 have signals that are in phase with the excitation signal; coils 2, 4, 6, 8, and 10 have no level signals.

[0054] 2. When a mover enters the induction area of ​​coil 3:

[0055] Coils 1 and 3 have signals; coil 2 has no signal, and coil 4 has a signal; the signal of coil 10 is in phase with the excitation signal; the MCU control chip performs AD sampling on coil 10 and decodes it.

[0056] 3. When a mover enters the induction area of ​​coil 4:

[0057] Coils 1 and 3 have signals; coil 2 has no signal, and coil 4 has a signal; the signal of coil 10 is in anti-phase with the excitation signal; the MCU control chip performs AD sampling on coil 10 and decodes it.

[0058] In the method of the present invention, the mover of the linear motor is made of conductive material, the transmitting coil generates an alternating magnetic field, the alternating magnetic field generates eddy currents inside the mover induction shield, weakening the receiving magnetic field of the receiving coil, and then the total magnetic field induced voltage and the logic voltage of each position are sampled, and finally the mover position is calculated by the MCU control chip.

[0059] The method of the present invention has good manufacturing consistency and high PCB coil processing accuracy; and does not require a permanent magnetic head, greatly reducing system costs and having high consistency.

[0060] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0061] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are illustrative and cannot be understood as limiting the present invention. Those skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for detecting the position of a linear motor rotor based on the principle of magnetic induction, characterized in that: The invention comprises a stator assembly, a movable induction head, an MCU control chip, a drive circuit, a power drive circuit, a filter / buffer circuit and an amplifier circuit. The stator assembly comprises a linear stator module and an arc-shaped stator module connected in sequence. The linear stator module and the arc-shaped stator module are both provided with a stator coil group, a transmitting coil group and a receiving coil group. When the movable induction head moves on the stator assembly, the receiving magnetic field of the receiving coil group changes. The MCU control chip samples the total magnetic field induced voltage and the logic voltage of each stator module position through the filter / buffer circuit and the amplifier circuit, and calculates and obtains a control signal, which is transmitted to the control stator coil group through the power drive circuit, thereby driving the movable induction head to move. At the same time, the MCU control chip also provides a control signal to the transmitting coil group through the drive circuit. The steps for detecting the position of the mover sensor head are as follows: Step 1: Power on and initialize; Step 2: The MCU control chip reads the digital IO level status; Step 3: The MCU control chip determines the absolute position of the mover sensor head according to the coding table; Step 4: MCU controls the chip to read the ADC value; Step 5: Decode to obtain the relative position of the mover sensor head; Step 6: Update the position information of the mover sensor head; By repeating steps 2 to 5 continuously, the position information of the mover sensor head can be updated in real time.

2. The method for detecting the position of a linear motor rotor based on the magnetic induction principle according to claim 1, characterized in that: It also includes a comparison circuit. The IO port of the MCU control chip collects information through the comparison circuit, and determines the initial position information of the linear stator module or the arc stator module where the mover sensing head is located through the absolute position decoding table built into the MCU control chip.

3. The method for detecting the position of a linear motor rotor based on the magnetic induction principle according to claim 1, characterized in that: The transmitting coil groups are sequentially connected in series and connected to the drive circuit, and the coil winding directions of the transmitting coil groups are consistent; the receiving coil groups are sequentially connected in series, and the coil winding directions of adjacent receiving coil groups are opposite.

4. The method for detecting the position of a linear motor rotor based on the magnetic induction principle according to claim 1, wherein: The transmitting coil groups are connected in parallel to the driving circuit, and the coil winding directions of the transmitting coil groups are consistent; the receiving coil groups are connected in series in sequence, and the coil winding directions of adjacent receiving coil groups are opposite.

5. The method for detecting the position of a linear motor rotor based on the magnetic induction principle according to claim 1, wherein: The receiving coil assembly includes at least two layers of coil units stacked on each other, and the phase difference between the two layers of coil units is 90°.

6. The method for detecting the position of a linear motor rotor based on the magnetic induction principle according to claim 1, characterized in that: The mover induction head is made of magnetic conductive material.

Images