Hollow steering wheel angle sensor for agricultural machinery

Abstract

The invention discloses a hollow steering wheel angle sensor for agricultural machinery, which adopts a hollow sensor main body, and four corners of the hollow sensor main body are provided with outer connecting holes, so that the hollow steering wheel angle sensor can be conveniently fixed with a vehicle body; one side of the sensor is provided with a cross-shaped PCB circuit board installation groove, a PCB circuit board and four Hall chips forming 90 degrees with each other are installed in the installation groove, and changes of a magnetic field are sensed in an omnibearing mode. A transmission wheel is arranged in the center hole and matched with the transmission shaft, and an annular magnet is fixed to the wheel and matched with a Hall chip to collect steering wheel turning angle information. An angle detection decoding chip, a microprocessor, a power supply chip and a CAN bus chip are integrated on the PCB, so that multiple functions of signal conversion, data processing, communication and power supply are realized; and the lower cover plate and the sensor main body enclose a sealed cavity which is filled with an insulating sealant, so that the protection grade is improved. The sensor solves the problems of complicated modification, complicated structure and insufficient protection of the steering wheel angle sensor of the agricultural machinery, realizes easy installation, high stability and strong protection, and provides reliable guarantee for the agricultural machinery.

Description

Technical Field

[0001] The invention belongs to the technical field of angle sensors, and in particular relates to a hollow steering wheel angle sensor for agricultural machinery. Background Art

[0002] As a core component in automobiles and non-road vehicles (such as agricultural machinery) that use steering wheel to control steering, the importance of steering wheel angle sensors is self-evident. The main function of this sensor is to accurately convert the steering wheel rotation angle into analog or digital signals through physical principles such as photoelectricity, Hall, and magnetoresistance, and send them to the vehicle's electronic control unit (ECU) in real time. This conversion process provides crucial position feedback for the vehicle's wire-controlled steering system, ensuring the accuracy and real-time nature of the steering operation.

[0003] In recent years, with the booming market of agricultural machinery autonomous driving, more and more agricultural machinery have begun to install steering wheel angle sensors to meet the needs of automated and intelligent steering control. However, in the existing technology, most steering wheel angle sensors used in agricultural machinery are directly derived from automotive parts. Although this "take-it-as-it-is" approach meets basic needs to a certain extent, it also exposes a series of defects and deficiencies.

[0004] First, the complexity of the modification process is a significant problem. Due to the differences in structure and size between agricultural machinery and automobiles, directly using automotive-grade steering wheel angle sensors often requires tedious modification and adaptation of the mechanical structure of the steering column, which not only increases the difficulty of installation, but also may lead to potential mechanical failure risks.

[0005] Secondly, existing sensors also have limitations in the way they obtain steering wheel angles. Most sensors rely on a gear transmission mechanism to transmit the rotation of the steering wheel to the sensor core. This design not only increases the complexity of the structure, but also reduces the reliability and durability of the sensor. At the same time, the gear transmission mechanism has extremely high requirements for precision and assembly. Once a failure or wear occurs, it will directly affect the measurement accuracy of the sensor.

[0006] In addition, the dust and water resistance of existing sensors is also a major shortcoming. Since there is a precise gear transmission mechanism inside the sensor, sealing measures such as rubber rings are required to prevent the intrusion of dust and moisture. However, this sealing method is often difficult to completely isolate the impact of harsh environments on the sensor, especially under the harsh conditions of agricultural machinery operations (such as on-demand vibration, rain, mud splashing, etc.), the performance and life of the sensor will be seriously affected.

[0007] In view of the above problems existing in the prior art, the present invention proposes a steering wheel angle sensor specially used for agricultural machinery. Summary of the invention

[0008] In view of the problems existing in the prior art, the present invention provides a steering wheel angle sensor specifically for agricultural machinery, which solves the problems of complex modification, cumbersome structure and insufficient protection of steering wheel angle sensors for agricultural machinery, and achieves easy installation, high stability and strong protection.

[0009] The present invention is implemented as follows: a hollow steering wheel angle sensor for agricultural machinery, characterized in that: it includes a hollow sensor body, the four corners of the sensor body are provided with external connection holes fixed to the vehicle body, and one side of the sensor body is provided with a cross-shaped PCB circuit board mounting groove; a PCB circuit board is installed in the PCB circuit board mounting groove, and four Hall chips with an angle of 90° to each other are installed on the PCB circuit board; a transmission wheel cooperating with a transmission shaft is provided in the center hole of the sensor body, and a ring magnet cooperating with the Hall chip is fixed on the transmission wheel; the Hall chip and the ring magnet are used to collect the steering wheel angle information; the PCB circuit board is also installed with an angle detection decoding chip, a microprocessor, a power supply chip and a CAN bus chip; wherein the angle detection decoding chip, Used to convert the analog signal output by the Hall sensor into digital angle information; the microprocessor is used to process the angle information in real time and communicate with other devices or systems; the power chip is responsible for providing power supply for the Hall chip, angle detection decoding chip, microprocessor, power chip and CAN bus chip on the PCB circuit board; the CAN bus chip is used to transmit the angle information or other related data to other devices or systems in the form of CAN bus protocol to achieve data sharing and collaborative control; a wire outlet hole is provided on one side of the sensor body, and a wiring terminal connected to the PCB circuit board is installed in the wire outlet hole for the transmission of current, wires and signals; a lower cover is provided on the upper part of the sensor body, and the lower cover encloses the PCB circuit board installation groove to form a sealed chamber, and the chamber is filled with insulating sealant.

[0010] Further preferably, the four Hall chips are all linear Hall chips. 霍尔输出电压峰峰值小于 0.8V。 The peak-to-peak value of the sinusoidal signal must be less than 0.8V, and at the same time, it must be greater than 1V and less than the conversion voltage (VDD) of the power chip -0.3V.

[0011] Further preferably, the Hall chip adopts MT9101A or MT910x series chip or DRV505x series chip.

[0012] Further preferably, the angle detection decoding chip uses MT6709 or MT6728 or MLX90380 to convert the Hall sine and cosine signals into SPI signals.

[0013] Further preferably, the microprocessor adopts a microprocessor of the STM32F103T8U6, GD32F103T8U6 or APM32F103T8U6 model.

[0014] Further preferably, the power chip is XL7005A.

[0015] Further preferably, the CAN bus chip adopts a CAN bus chip of model SN65HVD230.

[0016] Further preferably, the annular magnet is made of neodymium iron boron and is radially magnetized in a single pair of stages.

[0017] Further preferably, a sealing groove for accommodating a sealing rubber ring is provided on the outer periphery of the PCB circuit board mounting groove.

[0018] Further preferably, an X-shaped sealing rubber ring is provided on the outer circumference of the transmission wheel.

[0019] Advantages and technical effects of the present invention: The sensor is designed with full consideration of the characteristics and requirements of agricultural machinery. By optimizing the shape and installation method of the sensor, it achieves perfect matching with the hydraulic steering gear and direct series installation without any modification to the original mechanical structure. At the same time, the present invention adopts the method of arranging Hall sensors around the detected shaft to read the rotation angle, completely abandoning the complex gear transmission mechanism, simplifying the internal structure, reducing costs, and improving the stability and reliability of the product. In addition, in order to adapt to the harsh environment of agricultural machinery operations, the present invention also adopts an overall glue filling process, so that the sensor reaches a higher level of protection and can fully cope with various harsh working conditions faced by agricultural machinery. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of an embodiment of the present invention;

[0021] Figure 2 It is a top view with the lower cover removed;

[0022] Figure 3 It is a schematic diagram of the three-dimensional structure without the lower cover plate;

[0023] Figure 4 Schematic diagram of the lower cover structure;

[0024] Figure 5 It is a control block diagram of an embodiment of the present invention.

[0025] In the figure, 1. External connection hole; 2. PCB circuit board fixing hole; 3. Hall chip; 4. PCB circuit board; 5. Wire outlet hole; 6. Sealing groove; 7. Sensor body; 8. Ring magnet; 9. Transmission wheel; 10. Mutually matching installation holes; 12. Lower cover; 13. Quick release tongue. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] See also Figures 1 to 5A hollow steering wheel angle sensor for agricultural machinery includes a hollow sensor body 7. The hollow design allows the sensor to be easily mounted on the transmission shaft without modifying the original mechanical structure, thereby simplifying the installation process and improving adaptability. The sensor body is provided with external connection holes 1 at the four corners thereof for fixing to the vehicle body. Through the external connection holes at the four corners, the sensor can be firmly fixed to the vehicle body, thereby ensuring stability and reliability during the operation of the agricultural machinery. A cross-shaped PCB circuit board mounting groove is provided on one side of the sensor body; the cross-shaped design not only saves space, but also provides a stable mounting position for the PCB circuit board, thereby ensuring the stability and safety of the circuit board.A PCB circuit board fixing hole 2 is provided in the PCB circuit board mounting groove, a PCB circuit board 4 is installed on the PCB circuit board fixing hole, and four Hall chips 3 are installed on the PCB circuit board at 90 degrees to each other. The four Hall chips are arranged at 90 degrees to each other, and can sense the magnetic field changes in all directions, thereby improving the accuracy and precision of angle measurement; a transmission wheel 9 matched with the transmission shaft is provided in the central hole of the sensor body, and a ring magnet 8 matched with the Hall chip is fixed on the transmission wheel. The cooperation between the transmission wheel and the transmission shaft enables the sensor to directly obtain the rotation information of the steering wheel, and the cooperation between the ring magnet and the Hall chip realizes non-contact angle measurement, thereby improving the stability of the measurement. The Hall chip and the annular magnet are used to collect the steering wheel angle information. This combination realizes the real-time and accurate collection of the steering wheel angle information, and provides a reliable data basis for the subsequent angle calculation and control. The PCB circuit board is also equipped with an angle detection decoding chip, a microprocessor, a power chip and a CAN bus chip. A variety of functional chips are integrated, so that the sensor has multiple functions such as signal conversion, data processing, and communication, which improves the integration and intelligence level of the sensor. Among them, the angle detection decoding chip is used to convert the analog signal output by the Hall sensor into digital angle information, realizing the conversion of analog signals to digital signals, which is convenient for subsequent Digital processing and control improve the accuracy and stability of measurement; the microprocessor is used to process the angle information in real time and communicate with other devices or systems. The introduction of the microprocessor enables the sensor to process the angle information in real time and exchange data with other devices or systems through the communication interface, realizing data sharing and collaborative control; the power chip is responsible for providing power supply for the Hall chip, angle detection decoding chip, microprocessor, power chip and CAN bus chip on the PCB circuit board; the CAN bus chip is used to transmit the angle information or other related data to other devices or systems in the form of CAN bus protocol, realizing data sharing and collaborative control, realizing The fast and reliable transmission of data improves the coordinated control performance of the entire system; a wire outlet hole 5 is provided on one side of the sensor body, and a wiring terminal connected to the PCB circuit board is installed in the wire outlet hole for the transmission of current, wires and signals; a lower cover plate 12 is provided on the sensor body, and a quick-release plug tongue 13 for easy disassembly is provided on the lower cover plate. The sensor body and the lower cover plate are also provided with mutually matching mounting holes 10. The lower cover plate encloses the PCB circuit board mounting groove to form a sealed chamber, and the chamber is filled with insulating sealant. The application of the lower cover plate and insulating sealant improves the protection level of the sensor, so that the sensor can be competent for the harsh environment in agricultural machinery operation, such as dustproof and waterproof.

[0028] Further preferably, the four Hall chips are all linear Hall chips. 霍尔输出电压峰峰值小于 0.8V。

[0029] Further preferably, the Hall chip adopts MT9101A or MT910x series chip or DRV505x series chip.

[0030] Further preferably, the angle detection decoding chip uses MT6709 or MT6728 or MLX90380 to convert the Hall sine and cosine signals into SPI signals.

[0031] Further preferably, the microprocessor adopts a microprocessor of the STM32F103T8U6, GD32F103T8U6 or APM32F103T8U6 model.

[0032] Further preferably, the power chip is XL7005A.

[0033] Further preferably, the CAN bus chip adopts a CAN bus chip of model SN65HVD230.

[0034] Further preferably, the annular magnet is made of neodymium iron boron and is radially magnetized in a single pair of stages.

[0035] Further preferably, a sealing groove 6 for accommodating a sealing rubber ring is provided on the outer periphery of the PCB circuit board mounting groove.

[0036] Further preferably, an X-shaped sealing rubber ring 11 is provided on the outer circumference of the transmission wheel.

[0037] The installation and working principle of the present invention are divided into several key steps and are described as follows:

[0038] 1. Installation and connection Series installation: This angle sensor is installed in series between the steering column and the hydraulic steering gear to ensure that it can accurately sense the rotation information of the steering wheel. Drive shaft connection: The sensor is connected to the steering column through a drive shaft, so that when the steering wheel turns, the drive shaft can transmit the rotation information to the sensor.

[0039] 2. Steering wheel rotation and signal generation Customized magnetic ring rotation: The customized magnetic ring installed on the transmission shaft rotates with the rotation of the steering wheel. This magnetic ring is a key component for generating magnetic field changes. Hall chip sensing: The four Hall chips in the sensor are arranged at 90° to each other, and they can sense the change in magnetic field strength when the magnetic ring rotates. When the magnetic ring rotates, the Hall chip will output sine and cosine signals according to the change in the magnetic field.

[0040] 3. Signal processing and transmission Angle detection decoding: The angle detection decoding chip receives the sine and cosine signals output by the Hall chip, and resolves these analog signals into digital signals. This process ensures the accuracy and digitization of the angle information, which is convenient for subsequent processing. Microprocessor analysis: Through the SPI interface, the angle detection decoding chip transmits the digital signal to the microprocessor. The microprocessor has a built-in algorithm that can process these digital signals in real time and finally obtain the angle signal of the steering wheel rotation. CAN bus transmission: The microprocessor transmits the resolved angle signal to other required devices through the CAN bus according to the requirements of the protocol. This process realizes data sharing and collaborative control, allowing the entire steering system to respond to the rotation of the steering wheel more accurately.

[0041] 4. Synergy of steering column: The steering column serves as a bridge between the steering wheel and the steering system, and plays a role in transmitting steering torque when the steering wheel turns. This angle sensor accurately measures the steering wheel rotation angle by sensing the rotation information during this transmission process. Synergistic control: Through the synergy with the steering column, this angle sensor can provide high-precision and high-real-time position feedback for the entire steering system. This enables agricultural machinery to more accurately control the steering angle and steering speed in automatic driving or assisted driving mode, thereby improving work efficiency and safety.

[0042] In summary, the angle sensor is installed in series between the steering column and the hydraulic steering gear, and uses the Hall chip to sense the change in magnetic field strength when the magnetic ring on the transmission shaft rotates, and converts the steering wheel rotation information into digital signals for transmission through a series of signal processing processes. This working principle not only ensures the accuracy and real-time performance of angle measurement, but also improves the operating efficiency and safety of agricultural machinery in complex environments.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A hollow steering wheel angle sensor for agricultural machinery, characterized in that: It comprises a hollow sensor body, wherein the four corners of the sensor body are provided with external connection holes fixed to the vehicle body, and one side of the sensor body is provided with a cross-shaped PCB circuit board mounting groove; a PCB circuit board is mounted in the PCB circuit board mounting groove, and four Hall chips are mounted on the PCB circuit board at 90 degrees to each other; A transmission wheel matched with the transmission shaft is arranged in the central hole of the sensor body, and a ring magnet matched with the Hall chip is fixed on the transmission wheel; The Hall chip and the ring magnet are used to collect the steering wheel angle information; The PCB circuit board is also equipped with an angle detection decoding chip, a microprocessor, a power chip and a CAN bus chip; Among them, the angle detection decoding chip is used to convert the analog signal output by the Hall sensor into digital angle information; A microprocessor for real-time processing of angle information and communication with other devices or systems; The power chip is responsible for providing power supply for the Hall chip, angle detection decoding chip, microprocessor, power chip and CAN bus chip on the PCB circuit board; CAN bus chip, used to transmit angle information or other related data to other devices or systems in the form of CAN bus protocol, to achieve data sharing and collaborative control; A wire outlet hole is provided on one side of the sensor body, and a wiring terminal connected to the PCB circuit board is installed in the wire outlet hole for transmitting current, wire and signal; A lower cover plate is arranged on the sensor body, and the lower cover plate encloses the PCB circuit board installation groove to form a sealed chamber, and the chamber is filled with insulating sealant.

2. The hollow steering wheel angle sensor for agricultural machinery according to claim 1, characterized in that: The four Hall chips are all linear Hall chips, and the peak-to-peak value of the Hall output voltage is less than 0.8V.

3. The hollow steering wheel angle sensor for agricultural machinery according to claim 1, characterized in that: The Hall chip adopts MT9101A or MT910x series chip or DRV505x series chip.

4. The hollow steering wheel angle sensor for agricultural machinery according to claim 1, characterized in that: The angle detection decoding chip uses MT6709 or MT6728 or MLX90380 to convert Hall sine and cosine signals into SPI signals.

5. The hollow steering wheel angle sensor for agricultural machinery according to claim 1, characterized in that: The microprocessor adopts a microprocessor of the STM32F103T8U6, GD32F103T8U6 or APM32F103T8U6 model.

6. The hollow steering wheel angle sensor for agricultural machinery according to claim 1, characterized in that: The power chip is XL7005A.

7. The hollow steering wheel angle sensor for agricultural machinery according to claim 1, characterized in that: The CAN bus chip adopts the SN65HVD230 CAN bus chip.

8. The hollow steering wheel angle sensor for agricultural machinery according to claim 1, characterized in that: The annular magnet is made of neodymium iron boron and is magnetized radially in single-pair stages.

9. The hollow steering wheel angle sensor for agricultural machinery according to claim 1, characterized in that: A sealing groove for accommodating a sealing rubber ring is provided on the outer periphery of the PCB circuit board mounting groove.

10. The hollow steering wheel angle sensor for agricultural machinery according to claim 1, characterized in that: An X-shaped sealing rubber ring is arranged on the outer circumference of the transmission wheel.

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