Eccentric shaft position sensing system for low-altitude economical rotor engine and using method

Abstract

The invention discloses an eccentric shaft position sensing system for a low-altitude economical rotor engine and a using method, and belongs to the technical field of engine control. The thin-wall disc type magnetic induction wheel is fixed to the front end of the eccentric output shaft, a special magnetization area and a dense magnetization area are arranged on the working face, the Hall sensor is installed on a front shell of an engine through a fastening screw, an air gap is reserved between the Hall sensor and the magnetic induction wheel, digital square waves capable of being directly read by an ECU are output, and the Hall sensor and the magnetic induction wheel cooperate to form an anti-interference link. During use, the magnetic induction wheel rotates to enable the sensor to generate a square signal, the ECU identifies a reference signal to lock the position and stroke of the rotor, calculates the rotating speed and angle and dynamically compensates for the ignition oil injection moment; when the signal is abnormal, the part is checked and replaced through the processes of fault code reading, electrical detection, waveform observation and the like. According to the invention, the defects of a traditional sensor are overcome, the advantages in the aspects of environmental adaptability, control precision, anti-interference capability, structural adaptability and the like are obvious, the application potential of a rotor engine can be released, and safe and efficient operation of a low-altitude aircraft power system is ensured.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of engine control, and particularly relates to an eccentric shaft position sensing system for a low-altitude economic rotor engine and a use method. BACKGROUND

[0002] As a new strategic industry, the core carriers such as unmanned aerial vehicles and vertical take-off and landing aircraft have extremely strict requirements for power systems. The rotor engine is considered as one of the ideal power sources for low-altitude aircraft due to its inherent high power density, low vibration and compact structure.

[0003] However, the traditional crankshaft position sensor, such as a magneto sensor or a variable reluctance sensor, has obvious shortcomings such as weak anti-electromagnetic interference and poor temperature resistance when applied to the rotor engine, which further affects the key parameters of ignition and fuel injection timing control, and the failure of ignition or control may lead to serious consequences. Therefore, there is an urgent need for a sensing scheme that can adapt to the special working environment of the rotor engine, provide stable, accurate and real-time position signals, and fully release the potential of the rotor engine in the low-altitude economic field. SUMMARY

[0004] To solve the problems in the background art, the application provides an eccentric shaft position sensing system for a low-altitude economic rotor engine and a use method.

[0005] To achieve the above-mentioned purpose, the application adopts the following technical scheme: an eccentric shaft position sensing system for a low-altitude economic rotor engine, comprising a Hall-type eccentric shaft position sensor, a magnetic sensing wheel and an engine front housing. The magnetic sensing wheel is a thin-walled disc structure adapted to the internal space of the engine housing, and is fixedly installed at the front end of the eccentric output shaft of the rotor engine and rotates synchronously with the shaft. The working surface of the magnetic sensing wheel is provided with a plurality of magnetized areas, which include a special magnetized area for providing a top dead center reference and a densely distributed magnetized area adapted to the control accuracy of the engine. The Hall-type eccentric shaft position sensor is fixedly installed on the engine front housing by two fastening screws. An air gap is provided between the sensing end of the Hall-type eccentric shaft position sensor and the working surface of the magnetic sensing wheel. The output signal of the Hall-type eccentric shaft position sensor is a digital square wave, which can be directly read by the ECU. The magnetic sensing wheel and the Hall-type eccentric shaft position sensor cooperatively form an anti-interference sensing link.

[0006] The preset air gap range between the Hall-type eccentric shaft position sensor and the magnetic sensing wheel is 0.5mm to 1.5mm.

[0007] The magnetization area distribution angle of the magnetic sensing wheel matches the working characteristics of the rotor engine, realizes phase matching optimization, supports the ECU to compensate the rotor engine angular acceleration dynamic process in real time, and guarantees the accuracy of ignition and fuel injection under variable speed conditions.

[0008] The special magnetization area on the magnetic sensing wheel has a magnetic field variation rule that is significantly different from the rest of the magnetization area, which can be quickly identified by the ECU and determine the absolute phase of the engine, providing a basis for fuel injection and ignition sequence control.

[0009] The use method includes the following steps: S1: The magnetic sensing wheel rotates synchronously with the eccentric output shaft of the rotor engine, and the different magnetization areas of its working surface alternately pass through the sensing end of the Hall-type eccentric shaft position sensor, so that the sensor outputs a digital square wave pulse signal with alternating high and low levels; S2: The ECU receives the square wave pulse signal, identifies the reference signal generated by the special magnetization area of the magnetic sensing wheel, and quickly locks the rotor top dead center position and the current working stroke of the engine; S3: The ECU accurately calculates the instantaneous speed of the eccentric shaft by counting the number of square wave pulses received per unit time; at the same time, by counting the number of pulses after the reference signal, the accurate rotation angle of the eccentric shaft is determined, and based on the characteristics of the rotor engine and the dynamic change of angular acceleration, the ignition and fuel injection time are compensated in real time to ensure accurate control under all conditions; S4: When the ECU detects signal abnormalities, or the engine has symptoms such as starting difficulty, acceleration weakness, shaking, misfire, and instrument panel check engine light, etc., use a diagnostic scanner to connect the engine OBD interface, read the fault codes related to the Hall-type eccentric shaft position sensor, the fault codes include P0335 and P0336; S5: Disconnect the plug of the Hall-type eccentric shaft position sensor, turn on the ignition switch but do not start the engine, and use a multimeter to measure the voltage between the power pin and ground, the resistance between the grounding pin and ground, and the voltage of the signal pin, to verify whether the circuit connection is normal; S6: Connect the probe of channel one of the oscilloscope to the signal output pin of the Hall-type eccentric shaft position sensor, and connect the probe clip to the ground. After starting the engine, observe the output waveform to determine whether the waveform is uniform, clean, and the upper and lower edges are steep, and whether the reference signal is normal; S7: Check whether there is physical damage, cracks or oil stains on the surface of the Hall-type eccentric shaft position sensor, and use a non-magnetic feeler gauge to detect whether the air gap between the sensor and the magnetic sensing wheel meets the requirements of 0.5mm to 1.5mm, and at the same time check whether the magnetic sensing wheel has problems such as missing teeth, broken teeth or foreign matter adsorption that affect signal transmission; S8: If the Hall effect eccentric shaft position sensor or magnetic wheel is found to be damaged, replace the corresponding parts, tighten the fastening screws to the standard torque and reconnect the plug. Clear the fault code with a diagnostic tool or perform ECU reset and position learning to restore the system to the normal working state of S1-S3.

[0010] Compared with the prior art, the beneficial effects of the present invention are: 1. Excellent environmental adaptability: The Hall sensor itself is resistant to high temperature, vibration, and pollution. Combined with a specially designed magnetic wheel, the entire system can work stably for a long time in the harsh internal environment of a rotary engine with high temperature and high vibration. It has a long lifespan and requires no maintenance, making it perfectly suited for the demanding operating conditions of low-altitude aircraft. 2. Precise control under all operating conditions: Through the signal coordination design of the magnetic wheel and Hall sensor, combined with the phase matching optimization of the rotor engine's three combustion power per revolution, and the real-time compensation of the rotor engine's angular acceleration dynamic process by the ECU, stable and clear digital signals can be output from zero speed start to rapid acceleration and deceleration, ensuring the accuracy of ignition and fuel injection under all operating conditions of low-altitude aircraft such as hovering, climbing, and cruise, and smooth and reliable power response.

[0011] 3. Strong anti-electromagnetic interference capability: Through the digital square wave signal output characteristics of the Hall sensor, combined with the coordinated magnetic circuit adaptation design of the magnetic wheel and the sensor, a strong anti-interference sensing link is formed, which can effectively resist the electromagnetic interference generated by high-power equipment such as ESC and communication systems on low-altitude aircraft, significantly improve the signal-to-noise ratio, and adapt to the airborne environment with dense electrical equipment.

[0012] 4. Excellent system integration and adaptability: The entire sensing system adopts a compact assembly design. Through the optimization of the spatial layout of sensors and magnetic wheels, it makes full use of the limited axial space at the end of the rotor engine to achieve efficient integration with the engine casing. It is not a simple transplantation of existing technology, but rather a system-level structural adaptation and signal coordination innovation for the special operating conditions of low-altitude economic rotor engines, realizing integrated "mechanical-electrical-magnetic" collaborative work.

[0013] 5. Convenient and efficient use and maintenance: The sensor output signal can be directly read by the ECU, simplifying circuit design; the supporting fault diagnosis (fault code reading, electrical inspection, waveform detection) and replacement matching process is clear and standardized, which can quickly locate and solve system problems and reduce maintenance costs.

[0014] In summary, this invention effectively overcomes the shortcomings of traditional sensors through synergistic innovation in structure, magnetic circuit, and control logic. It has significant advantages in environmental adaptability, control accuracy, anti-interference capability, structural adaptability, and ease of maintenance. It can fully unleash the application potential of rotary engines in the low-altitude economic field and ensure the absolute safety and efficient operation of the power system of low-altitude aircraft. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a waveform diagram of the signal output of the magnetic induction wheel and the Hall effect eccentric shaft position matching of the present invention. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0017] This embodiment describes an eccentric shaft position sensing system for a low-altitude economic rotary engine, including a Hall-type eccentric shaft position sensor 1, a magnetic wheel 2, and an engine front housing 4. The magnetic wheel 2 is a thin-walled disc structure adapted to the internal space of the engine housing. The magnetic wheel 2 is fixedly installed at the front end of the eccentric output shaft of the rotary engine and rotates synchronously with the shaft. The working surface of the magnetic wheel 2 has multiple sets of magnetization areas, including a special magnetization area for providing a top dead center reference and a densely distributed magnetization area adapted to the engine control precision. The Hall effect eccentric shaft position sensor 1 is fixedly installed on the front housing 4 of the engine by two fastening screws 3. There is an air gap between the sensing end of the Hall effect eccentric shaft position sensor 1 and the working surface of the magnetic wheel 2. The output signal of the Hall effect eccentric shaft position sensor 1 is a digital square wave, which can be directly read by the ECU. The magnetic wheel 2 and the Hall effect eccentric shaft position sensor 1 work together to form an anti-interference sensing link.

[0018] The preset air gap range between the Hall effect eccentric shaft position sensor 1 and the magnetic wheel 2 is 0.5mm to 1.5mm.

[0019] The magnetization region distribution angle of the magnetic wheel 2 is matched with the working characteristics of the rotary engine, realizing phase matching optimization, supporting the ECU to perform real-time compensation for the dynamic process of angular acceleration of the rotary engine, and ensuring the accuracy of ignition and fuel injection under variable speed conditions.

[0020] The special magnetized area on the magnetic wheel 2 has a magnetic field variation pattern that is significantly different from that of the other magnetized areas. It can be quickly identified by the ECU and the absolute phase of the engine can be determined, providing a basis for fuel injection and ignition sequence control.

[0021] The method of use includes the following steps: S1: The magnetic wheel 2 rotates synchronously with the eccentric output shaft of the rotor engine. Different magnetized areas of its working surface alternately pass through the sensing end of the Hall-type eccentric shaft position sensor 1, causing the sensor to output digital square wave pulse signals with alternating high and low levels. S2: The ECU receives the square wave pulse signal, identifies the reference signal generated by the special magnetization area of ​​the magnetic wheel 2, and quickly locks the rotor top dead center position and the current working stroke of the engine. S3: The ECU accurately calculates the instantaneous rotational speed of the eccentric shaft by counting the number of square wave pulses received per unit time; at the same time, it determines the precise rotation angle of the eccentric shaft by counting the number of pulses after the reference signal, and performs real-time compensation for ignition and fuel injection timing based on the characteristics of the rotary engine and the dynamic changes in angular acceleration, ensuring precise control under all operating conditions. S4: When the ECU detects an abnormal signal, or when the engine has symptoms such as difficulty starting, weak acceleration, shaking, stalling, and the dashboard indicator light illuminating, use a diagnostic scanner connected to the engine OBD interface to read the fault codes related to Hall effect eccentric shaft position sensor 1. The fault codes include P0335 (eccentric shaft position sensor circuit fault) and P0336 (eccentric shaft position sensor circuit range or performance problem). S5: Disconnect the plug of Hall-effect eccentric shaft position sensor 1, turn on the ignition switch but do not start the engine, and use a multimeter to measure the voltage to ground of the sensor power supply pin (should be 5V reference voltage), the resistance to ground of the ground pin (should be close to 0 ohms), and the voltage of the signal pin (0V or 5V) to verify whether the circuit connection is normal. S6: Connect the oscilloscope channel one probe to the signal output pin of Hall effect eccentric shaft position sensor 1, connect the probe clip to ground, start the engine and observe the output waveform to determine whether the waveform is uniform, clean, has steep upper and lower edges and whether the reference signal is normal. S7: Check whether there is physical damage, cracks or oil stains on the surface of Hall effect eccentric shaft position sensor 1. Use a non-magnetic feeler gauge to check whether the air gap between it and magnetic wheel 2 meets the requirement of 0.5mm to 1.5mm. At the same time, check whether there are problems such as missing teeth, broken teeth or foreign objects adsorbed on magnetic wheel 2 that affect signal transmission. S8: If the Hall effect eccentric shaft position sensor 1 or magnetic wheel 2 is found to be damaged, replace the corresponding parts, tighten the fastening screw 3 to the standard torque and reconnect the plug, clear the fault code with a diagnostic tool or perform ECU reset and position learning to restore the system to the normal working state of S1-S3.

[0022] The eccentric shaft position sensing system for a low-altitude economical rotary engine comprises a Hall-effect eccentric shaft position sensor 1, a magnetic wheel 2, fastening screws 3, and an engine front housing 4. The specific assembly and operation are as follows: The thin-walled disc-type magnetic wheel 2 (which can be made of neodymium iron boron permanent magnet alloy with a galvanized anti-corrosion surface) is fixedly installed at the front end of the eccentric output shaft of the rotary engine, allowing it to rotate synchronously with the eccentric shaft. This installation method fully utilizes the limited axial space inside the engine housing, achieving a compact fit. The working surface of the magnetic wheel 2 has multiple sets of magnetized areas that are compatible with the Hall-effect eccentric shaft position sensor. Magnetization creates north and south poles, which include angle signal teeth (…). A total of 58 special narrow teeth (each tooth angle is 6°±0.2°) and the tooth-missing area of ​​the top dead center reference signal (two tooth-missing areas) are optimized by phase matching to fully adapt to the characteristics of the rotor engine's three combustions per revolution, providing a structural basis for the system to output high-precision position signals; Hall-effect eccentric shaft position sensors 1 (selectable models with wide temperature range (-40℃-125℃) and high sensitivity (magnetic field sensitivity ≥10mV / mT, response frequency ≥1MHz)) are fixedly installed on the front housing 4 of the engine by two M5 specification fastening screws 3, so that the sensor sensing end and the working surface of the magnetic wheel 2 maintain a preset air gap of 0.5mm-1.5mm to ensure stable sensing of magnetic field signals.

[0023] When the system is working, the magnetic wheel 2 rotates with the eccentric shaft. The teeth and grooves on its working surface alternately pass through the sensing end of the Hall effect eccentric shaft position sensor 1. When the teeth pass through, they cut the magnetic lines of force, causing the sensor to output a low level of 0V. When the grooves pass through, the magnetic lines of force converge, causing the sensor to output a high level of 5V. This continuously generates a digital square wave pulse signal that can be directly read by the ECU (Engine Control Unit, the core control module of the rotary engine, responsible for receiving various sensor signals and executing key control commands such as ignition and fuel injection). (This signal improves the signal-to-noise ratio through the innovative magnetic circuit design of the magnetic wheel, and can resist electromagnetic interference generated by high-power equipment such as ESCs and communication systems on low-altitude aircraft). After receiving the square wave signal, the ECU first identifies... The reference signal generated by the missing tooth area of ​​the magnetic induction wheel 2, which is significantly different from other pulse widths, quickly locks the rotor top dead center position and the current intake, compression, power, and exhaust strokes of the engine. At the same time, it accurately calculates the instantaneous rotational speed of the eccentric shaft by statistically analyzing the number of pulses received per unit time, determines the precise rotation angle of the eccentric shaft by counting the number of pulses after the reference signal, and calculates the angular acceleration in real time based on the pulse interval change (dynamic compensation is activated when the absolute value of the angular acceleration exceeds 50 rad / s²). It performs real-time compensation for the special dynamic process of angular acceleration of the rotor engine, and adjusts the ignition and fuel injection advance angle by 0.5°-2° according to the compensation results to ensure that the ignition and fuel injection timing of the low-altitude aircraft is accurate in all operating conditions such as hovering, climbing, cruise, and rapid acceleration and deceleration.

[0024] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. An eccentric shaft position sensing system for a low-altitude economical rotary engine, characterized in that: Includes Hall effect eccentric shaft position sensor (1), magnetic wheel (2) and engine front housing (4); The magnetic wheel (2) is a thin-walled disc structure adapted to the internal space of the engine housing. The magnetic wheel (2) is fixedly installed at the front end of the eccentric output shaft of the rotor engine and rotates synchronously with the shaft. The working surface of the magnetic wheel (2) is provided with multiple sets of magnetization areas. The multiple sets of magnetization areas include a special magnetization area for providing the top dead center reference and a densely distributed magnetization area adapted to the engine control precision. The Hall-type eccentric shaft position sensor (1) is fixedly installed on the front housing (4) of the engine by two fastening screws (3). There is an air gap between the sensing end of the Hall-type eccentric shaft position sensor (1) and the working surface of the magnetic wheel (2). The output signal of the Hall-type eccentric shaft position sensor (1) is a digital square wave, which can be directly read by the ECU. The magnetic wheel (2) and the Hall-type eccentric shaft position sensor (1) work together to form an anti-interference sensing link.

2. The eccentric shaft position sensing system for a low-altitude economic rotary engine according to claim 1, characterized in that: The preset air gap range between the Hall-type eccentric shaft position sensor (1) and the magnetic wheel (2) is 0.5 mm to 1.5 mm.

3. The eccentric shaft position sensing system for a low-altitude economic rotary engine according to claim 1, characterized in that: The magnetization region distribution angle of the magnetic wheel (2) matches the working characteristics of the rotor engine, realizing phase matching optimization, supporting the ECU to perform real-time compensation for the dynamic process of angular acceleration of the rotor engine, and ensuring the accuracy of ignition and fuel injection under variable speed conditions.

4. The eccentric shaft position sensing system for a low-altitude economic rotary engine according to claim 1, characterized in that: The special magnetized area on the magnetic wheel (2) has a magnetic field change pattern that is significantly different from the other magnetized areas. It can be quickly identified by the ECU and the absolute phase of the engine can be determined, providing a basis for fuel injection and ignition sequence control.

5. A method of using the eccentric shaft position sensing system for a low-altitude economic rotary engine as described in claim 1, characterized in that: The method of use includes the following steps: S1: The magnetic wheel (2) rotates synchronously with the eccentric output shaft of the rotor engine. Different magnetized areas of its working surface pass alternately through the sensing end of the Hall-type eccentric shaft position sensor (1), causing the sensor to output a digital square wave pulse signal with alternating high and low levels. S2: The ECU receives the square wave pulse signal, identifies the reference signal generated by the special magnetization area of ​​the magnetic wheel (2), and quickly locks the rotor top dead center position and the current working stroke of the engine; S3: The ECU accurately calculates the instantaneous rotational speed of the eccentric shaft by counting the number of square wave pulses received per unit time; at the same time, it determines the precise rotation angle of the eccentric shaft by counting the number of pulses after the reference signal, and performs real-time compensation for ignition and fuel injection timing based on the characteristics of the rotary engine and the dynamic changes in angular acceleration, ensuring precise control under all operating conditions. S4: When the ECU detects an abnormal signal, or when the engine has symptoms such as difficulty starting, weak acceleration, shaking, stalling, and the dashboard lighting up the engine check light, a diagnostic scanner is used to connect to the engine OBD interface to read the fault codes related to the Hall-type eccentric shaft position sensor (1). The fault codes include P0335 and P0336. S5: Disconnect the plug of the Hall-type eccentric shaft position sensor (1), turn on the ignition switch but do not start the engine, use a multimeter to measure the voltage to ground of the sensor power supply pin, the resistance to ground of the ground pin and the voltage of the signal pin respectively, and verify whether the circuit connection is normal. S6: Connect the oscilloscope channel one probe to the signal output pin of the Hall-type eccentric shaft position sensor (1), connect the probe clip to ground, start the engine and observe the output waveform to determine whether the waveform is uniform, clean, has steep upper and lower edges and whether the reference signal is normal. S7: Check whether there is physical damage, cracks or oil stains on the surface of the Hall-type eccentric shaft position sensor (1). Use a non-magnetic feeler gauge to check whether the air gap between it and the magnetic wheel (2) meets the requirement of 0.5mm to 1.5mm. At the same time, check whether there are problems such as missing teeth, broken teeth or foreign matter adsorption on the magnetic wheel (2) that affect signal transmission. S8: If the Hall effect eccentric shaft position sensor (1) or magnetic wheel (2) is found to be damaged, replace the corresponding parts, tighten the fastening screw (3) to the standard torque and reconnect the plug, clear the fault code through the diagnostic tool or perform ECU reset and position learning, so that the system can be restored to the normal working state of S1-S3.

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