Magnetoelectric angular displacement sensor

Abstract

This invention belongs to the field of angular displacement sensor technology, particularly a magnetoelectric angular displacement sensor. It includes an output interface, a housing, a first rotary bearing, a drive shaft, a second rotary bearing, a magnet carrier, a magnet body, a bearing retaining ring body, a magnetic encoder chip, a circuit board body, a wire clip body, and an end cap body. The magnetic encoder chip is mounted in the middle of one side surface of the circuit board body. By employing advanced ARM magnetic induction technology and advanced signal processing technology, it senses changes in the direction of the magnetic field parallel to the surface of the magnetic encoder chip and outputs corresponding angle values. The magnetic encoder chip can output PWM signals, which are converted into current signals through a current output module. Alternatively, it can be connected to a CPU module via an SPI interface, processed by a corresponding algorithm, and output to a communication module, converted into a corresponding output type, and connected to an external receiving device to achieve intelligent and high-precision angle measurement.

Description

Technical Field

[0001] This invention belongs to the field of angular displacement sensor technology, specifically relating to a magnetoelectric angular displacement sensor. Background Technology

[0002] Most existing angular displacement sensors use photoelectric encoders and magnetic encoders.

[0003] In dusty and dirty environments such as industrial applications, contaminants may accumulate on the encoder wheel, preventing LED light from reaching the photosensitive sensor. The reliability and accuracy of the photoelectric encoder can be greatly affected by a dirty code disk. The square wave may become discontinuous or completely lost. LEDs have a limited lifespan and will eventually burn out, leading to encoder failure. In addition, glass or plastic encoders are susceptible to damage from extreme vibrations and temperatures, limiting the application range of photoelectric encoders in harsh environments. Photoelectric encoders have a complex structure, require high installation standards, and have high power consumption during normal operation, which affects other applications on mobile and battery-powered devices. They also rely heavily on mechanical switching, requiring the elimination of errors caused by mechanical backlash.

[0004] Meanwhile, other types of magnetic encoders have disadvantages: fixed accuracy, support for low speeds, low precision, limited application scenarios, single output interface, lack of self-calibration function, inability to implement customized logic functions, and inability to integrate more circuit designs, such as scenarios that use angle information to feed back some discrete quantities.

[0005] Therefore, it is necessary to propose a magnetoelectric angular displacement sensor to effectively improve the above problems. Summary of the Invention

[0006] To address the aforementioned problems in the existing technology, this invention provides a magnetoelectric angular displacement sensor, which features intelligent and high-precision angle measurement capabilities.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a magnetoelectric angular displacement sensor, comprising an output interface, a housing, a first rotary bearing, a drive shaft, a second rotary bearing, a magnet carrier, a magnet body, a bearing retaining ring body, a magnetic encoder chip, a circuit board body, a wire clip body, and an end cap body. The magnetic encoder chip is mounted at the middle position on one side surface of the circuit board body. The housing and the end cap body are fixedly connected by end cap fastening screws. The first rotary bearing, the drive shaft, the second rotary bearing, the magnet carrier, the magnet body, the bearing retaining ring body, the circuit board body, and the wire clip body are sequentially mounted from left to right in the internal space formed by the housing and the end cap body. An adjustment module group is mounted on the side of the circuit board body opposite to the magnetic encoder chip.

[0008] As a preferred technical solution of the magnetoelectric angular displacement sensor of the present invention, the adjustment module group includes a lead wire interface, a CPU module, a power conversion module, a current output module, a communication module, and a magnetic encoder drive module.

[0009] As a preferred technical solution of the magnetoelectric angular displacement sensor of the present invention, the magnetic encoder chip receives the directional changes parallel to the chip surface generated by the rotating magnet carrier, communicates with the CPU via the SPI bus, and transmits the encoded angle signal to the CPU module for processing.

[0010] As a preferred technical solution for the magnetoelectric angular displacement sensor of the present invention, the magnetic encoder chip is MT6835 and the CPU module is a domestically produced chip, GD32F130F6P6.

[0011] As a preferred embodiment of the magnetoelectric angular displacement sensor of the present invention, pin 5 of the MT6835 chip is connected to pin 12 of the GD32F130F6P6 chip, pin 6 of the MT6835 chip is connected to pin 13 of the GD32F130F6P6 chip, pin 7 of the MT6835 chip is connected to pin 11 of the GD32F130F6P6 chip, and pin 8 of the MT6835 chip is connected to pin 10 of the GD32F130F6P6 chip.

[0012] As a preferred technical solution for the magnetoelectric angular displacement sensor of the present invention, the communication module adopts the JMAX3485 chip.

[0013] As a preferred technical solution of the magnetoelectric angular displacement sensor of the present invention, the output interface is an adapter body, which is located on one side of the housing and is fixedly connected to it by adapter fastening screws.

[0014] As a preferred technical solution of the magnetoelectric angular displacement sensor of the present invention, the bearing fixing ring body, the circuit board body and the wire clamp body are respectively equipped with bearing fixing ring fastening screws, circuit board fastening screws and wire clamp fastening screws.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention includes a housing, a connecting shaft, a magnet, an output interface, a power conversion module, a CPU module, a magnetic angle encoder chip, a magnetic encoder drive module, a communication module, and a current output module. In use, by employing advanced ARM magnetic induction technology and advanced signal processing technology, the change in the direction of the magnetic field parallel to the surface of the magnetic encoder chip is sensed and the corresponding angle value is output. The magnetic encoder chip can output a PWM signal, which is converted into a current signal through the current output module.

[0016] It can also be connected to the CPU module via the SPI interface, processed by the corresponding algorithm, output to the communication module and converted into the corresponding output type, and connected to the external receiving device to realize intelligent and high-precision angle measurement.

[0017] This invention provides a low-cost, miniaturized, multi-interface, and intelligent angular displacement sensor. Compared to traditional photoelectric encoders, it features a simpler structure, stronger environmental adaptability, higher flexibility, stronger shock resistance, lower power consumption, faster response speed, higher reliability, and lower cost. Compared to other types of magnetically encoded angular displacement sensors, this invention incorporates intelligent software algorithms, enabling it to adapt to high-precision and multi-interface requirements. It is highly suitable for harsh environments, high-speed rotation, and low-cost industrial and military applications, offering the following advantages:

[0018] 1. Multiple interface outputs to meet different protocol requirements;

[0019] 2. Calibration can be performed through external means, and software algorithms improve accuracy;

[0020] 3. The connecting shaft adopts an adapter method, which can meet the needs of multiple scenarios by changing the connecting shaft. Attached Figure Description

[0021] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0022] Figure 1 This is a schematic diagram of the exploded structure of the present invention;

[0023] Figure 2 This is a partial exploded structural diagram of the present invention;

[0024] Figure 3 This is a schematic diagram of the combined structure of the present invention;

[0025] Figure 4 This is a schematic diagram of a partial combination structure of the present invention;

[0026] Figure 5 This is an overall block diagram of the magnetoelectric angular displacement sensor of the present invention;

[0027] Figure 6 This is a system architecture diagram of the present invention;

[0028] Figure 7 This is a partial circuit diagram of the present invention;

[0029] Figure 8 This is a timing diagram for reading angle data using SPI single byte in this invention;

[0030] Figure 9This is a data table diagram corresponding to the absolute angle register of this invention;

[0031] Figure 10 This is a schematic diagram of some of the calculation formulas of this invention;

[0032] Figure 11 This is a schematic diagram of the combined cross-section portion of the present invention;

[0033] Figure 12 This is a schematic diagram of the circuit board body of the present invention.

[0034] In the diagram: 1. Adapter fastening screw; 2. Adapter body; 3. Housing; 4. Rotary bearing one; 5. Drive shaft; 6. Rotary bearing two; 7. Magnet carrier; 8. Magnet body; 9. Bearing retaining ring body; 10. Bearing retaining ring fastening screw; 11. Magnetic encoder chip; 12. Circuit board body; 13. Circuit board fastening screw; 14. Cable clamp fastening screw; 15. Cable clamp body; 16. End cap body; 17. End cap fastening screw. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0036] Working principle of the invention: In use, the magnetoelectric angular displacement sensor is used in various fields such as motor position feedback control, absolute angle position sensor, DC brushless motor control, servo motor control, replacement of photoelectric encoder, and rotation control.

[0037] This invention employs a new generation of high-speed, high-precision angle encoder chip based on advanced anisotropic magnetoresistive technology. The chip integrates a sensing element composed of two pairs of Wheatstone bridges placed at 45° to each other, as well as a high-performance dedicated signal processing circuit. Since ARM devices operate in the saturation region when used for angle measurement applications, in actual operation, the chip only responds to the direction of the magnetic field parallel to the chip surface, regardless of the magnetic field strength. The peripheral CPU reads the 21-bit absolute angle value inside the chip through the SPI communication bus, while the single-wire output PWM can also provide 12-bit absolute angle data, which is converted into a current signal commonly used in industry.

[0038] This invention provides a magnetoelectric angular displacement sensor, see reference. Figure 1-12 As shown,

[0039] A magnetoelectric angular displacement sensor includes an output interface, a housing 3, a first rotary bearing 4, a drive shaft 5, a second rotary bearing 6, a magnet carrier 7, a magnet body 8, a bearing retaining ring body 9, a magnetic encoder chip 11, a circuit board body 12, a wire clip body 15, and an end cap body 16. The magnetic encoder chip 11 is mounted at the middle position on one side surface of the circuit board body 12. The housing 3 and the end cap body 16 are fixedly connected by end cap fastening screws 17. The first rotary bearing 4, drive shaft 5, second rotary bearing 6, magnet carrier 7, magnet body 8, bearing retaining ring body 9, circuit board body 12, and wire clip body 15 are sequentially installed from left to right within the internal space formed by the housing 3 and the end cap body 16. An adjustment module group is mounted on the side of the circuit board body 12 opposite to the magnetic encoder chip 11. The adjustment module group includes a lead wire interface, a CPU module, a power conversion module, a current output module, a communication module, and a magnetic encoder drive module. The module arrangement is as follows: Figure 12 As shown, the magnetic encoder chip 11 receives the directional changes parallel to the chip surface generated by the rotating magnet carrier 7, communicates with the CPU via the SPI bus, and transmits the encoded angle signal to the CPU module for processing.

[0040] The output interface is the adapter body 2, which is located on one side of the housing 3 and is fixedly connected to it by the adapter fastening screw 1. The bearing retaining ring body 9, the circuit board body 12 and the wire clamp body 15 are respectively equipped with bearing retaining ring fastening screw 10, circuit board fastening screw 13 and wire clamp fastening screw 14, so that the components can be stably connected together.

[0041] Meanwhile, the magnetic encoder chip 11 can be an MT6835, and the CPU module is a domestically produced GD32F130F6P6 chip. Pin 5 of the MT6835 chip is connected to pin 12 of the GD32F130F6P6 chip, pin 6 of the MT6835 chip is connected to pin 13 of the GD32F130F6P6 chip, pin 7 of the MT6835 chip is connected to pin 11 of the GD32F130F6P6 chip, and pin 8 of the MT6835 chip is connected to pin 10 of the GD32F130F6P6 chip. According to the circuit diagram, one end of capacitor C6 and Zener diode D1 are both grounded, and the other end of capacitor C6 is connected to the 3.3V power supply terminal and pin 9 of the MT6835 chip. Pins 11 and 12 of the MT6835 chip are both grounded, and pin 2 of the GD32F130F6P6 chip is connected to pin 3 of crystal oscillator Y1.

[0042] The communication module can use a JMAX3485 chip. Pins 2 and 3 of the JMAX3485 chip are connected to resistor R10, and the other end of resistor R10 is connected to 3.3V. Pin 4 of the JMAX3485 chip is connected to resistor R13, and the other end of resistor R13 is connected to pin 8 of the GD32F130F6P6 chip. Pin 5 of the JMAX3485 chip is connected to ground. Pins 6 and 7 of the JMAX3485 chip are connected to both ends of resistor R12. Pin 7 is pulled up by resistor R11 and connected to 3.3V, and pin 6 is pulled down by resistor R11 and connected to ground. Pin 8 of the JMAX3485 chip is connected to 3.3V and one end of capacitor C13, and capacitor C13 is connected to ground.

[0043] The product structure design of this invention adopts a double-row bearing optimized design scheme;

[0044] The internal drive shaft 5 of the product has a rotary bearing 4 and a rotary bearing 6 installed at both ends. The drive shaft 5, rotary bearing 4 and rotary bearing 6 are pressed into the shaft socket inside the housing 3, and then the bearing retaining ring body 9 is used to press the outer ring of the bearing. The above design increases the length of the rotation constraint surface and optimizes and reduces the bearing clearance and shaft swing. The output shaft of the sensor adopts an adapter connection method. This method can solve the adaptation problem of different application scenarios. By changing the output interface, it can meet the use of multiple scenarios.

[0045] Multiple positioning points are used in the installation of the internal circuit board body 12 to ensure consistency and accuracy in mass production; reduce the shaking of the circuit board body 12 and increase shock resistance; the internal circuit board body 12 is designed with miniaturized connectors, which makes the assembly process simpler and increases the maintainability of the sensor in the later stage.

[0046] This invention provides a low-cost, miniaturized, multi-interface, and intelligent angular displacement sensor. Compared to traditional photoelectric encoders, it features a simpler structure, stronger environmental adaptability, higher flexibility, stronger shock resistance, lower power consumption, faster response speed, higher reliability, and lower cost. Compared to other types of magnetically encoded angular displacement sensors, this invention incorporates intelligent software algorithms, enabling it to adapt to high-precision and multi-interface requirements. It is highly suitable for harsh environments, high-speed rotation, and low-cost industrial and military applications, offering the following advantages:

[0047] Multiple interface outputs to meet different protocol requirements;

[0048] Calibration can be performed through external means, while software algorithms improve accuracy.

[0049] The connecting shaft uses an adapter method, and by changing the connecting shaft, it can meet the needs of multiple scenarios.

[0050] The overall block diagram of the magnetoelectric angular displacement sensor is as follows: Figure 5As shown in the figure below, the overall block diagram of the magnetoelectric angular displacement sensor is as follows; the magnetoelectric angular displacement chip has an operating voltage of 3.3~5V, an accuracy of 21 bits, and provides absolute angle measurement from 0° to 360° based on the rotation angle of the magnetic field.

[0051] The sensor is powered by 5-15VDC, which is achieved through an internal 3.3V low dropout (LDO) voltage regulator. The internal power supply voltage is always taken from the output of the LDO, which means that the internal module always operates at 3.3V. In addition to powering the magnetic angle encoder, the power module also powers the CPU module, communication module, and current output module.

[0052] The CPU module uses the domestically produced GD32F130F6P6 chip. It outputs a clock signal via the SPI communication bus interface to acquire angle information from the magnetic encoder. After reading the angle signal, the CPU converts the encoded data into angle information and uses a high-precision interpolation algorithm to calibrate the angle information. Finally, the angle signal is output via the communication module using a pre-defined communication protocol and transmission rate. Another output interface allows the current output module to convert the PWM signal output by the magnetic encoder chip 11 into a 0-20mA or 4-20mA current signal.

[0053] The system architecture is as follows: Figure 6 As shown.

[0054] The peripheral components of the magnetoelectric angular displacement sensor circuit are selected from 7-star and above military grade capacitors, and the resistors are surface-mount resistors. Its circuit diagram is shown in Figure 7.

[0055] The power supply is connected to the VCC_IN pin, and VCC must be buffered by a 2.2-10µF capacitor, which should be placed close to the power supply pin; a 10µF capacitor is chosen for buffering here.

[0056] The PWM pin can be converted into a current signal using an external PAC chip GP8102S. A PWM signal with a 0%-100% duty cycle is input and linearly converted into a current signal output. A suitable sampling resistor Rs=250Ω is selected, resulting in an analog current output of 4-20mA / 0-20mA. For port protection, a unidirectional TVS is placed at the port, with a TVS voltage close to the power supply voltage placed outside pin 7. This method can directly replace the traditional current loop.

[0057] The interface for communication with the CPU unit uses the standard synchronous serial interface SPI. By reading the 24-bit data, the absolute angle position data and status information of the sensor can be obtained. Figure 4The SPI command shown reads only one byte of data per SPI communication, reading 21 bits of absolute angle data from the magnetic encoder chip 11 via SPI. The magnetic encoder chip 11 has an external latching mechanism for the current angle data. When the falling edge of the chip select signal CSN of the SPI communication is detected by the magnetic encoder chip 11, the data in the internal angle register 0x003-0x006 is latched until the data is read away. The chip can also define the 0° position of the output angle by setting the zero point register.

[0058] The timing diagram for reading angle data by SPI single byte is as follows: Figure 8 As shown.

[0059] The data table corresponding to the absolute angle register is as follows: Figure 9 As shown; where the absolute angle θ from 0 to 360° can be used Figure 10 The formula is used for calculation.

[0060] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A magnetoelectric angular displacement sensor, characterized in that, The device includes an output interface, a housing (3), a first rotary bearing (4), a drive shaft (5), a second rotary bearing (6), a magnet carrier (7), a magnet body (8), a bearing retaining ring body (9), a magnetic encoder chip (11), a circuit board body (12), a wire clip body (15), and an end cap body (16). The magnetic encoder chip (11) is installed at the middle position on one side surface of the circuit board body (12). The housing (3) and the end cap body (16) are fixedly connected by end cap fastening screws (17). The first rotary bearing (4), the drive shaft (5), the second rotary bearing (6), the magnet carrier (7), the magnet body (8), the bearing retaining ring body (9), the circuit board body (12), and the wire clip body (15) are installed from left to right in the internal space formed by the housing (3) and the end cap body (16). An adjustment module group is installed on the side of the circuit board body (12) opposite to the magnetic encoder chip (11).

2. The magnetoelectric angular displacement sensor according to claim 1, characterized in that: The adjustment module group includes a lead-out interface, a CPU module, a power conversion module, a current output module, a communication module, and a magnetic encoder drive module.

3. The magnetoelectric angular displacement sensor according to claim 2, characterized in that: The magnetic encoder chip (11) receives the directional changes parallel to the chip surface generated by the rotating magnet carrier (7), communicates with the CPU via the SPI bus, and transmits the encoded angle signal to the CPU module for processing.

4. The magnetoelectric angular displacement sensor according to claim 3, characterized in that: The magnetic encoder chip (11) is MT6835, and the CPU module is a domestic chip GD32F130F6P6.

5. The magnetoelectric angular displacement sensor according to claim 4, characterized in that: Pin 5 of the magnetic encoder chip (11) is connected to pin 12 of the CPU module, pin 6 of the magnetic encoder chip (11) is connected to pin 13 of the CPU module, pin 7 of the magnetic encoder chip (11) is connected to pin 11 of the CPU module, and pin 8 of the magnetic encoder chip (11) is connected to pin 10 of the CPU module.

6. The magnetoelectric angular displacement sensor according to claim 4, characterized in that: The communication module uses the JMAX3485 chip.

7. The magnetoelectric angular displacement sensor according to claim 1, characterized in that: The output interface is an adapter body (2), which is located on one side of the outer shell (3) and is fixedly connected to it by an adapter fastening screw (1).

8. The magnetoelectric angular displacement sensor according to claim 1, characterized in that: The bearing retaining ring body (9), the circuit board body (12), and the wire clamp body (15) are respectively equipped with bearing retaining ring fastening screws (10), circuit board fastening screws (13), and wire clamp fastening screws (14).

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