A helicopter landing gear magnetorheological damper and magnetorheological damping control system and method

Abstract

The application discloses a kind of helicopter landing gear magnetorheological buffer and magnetorheological damping control system and method, and magnetorheological buffer includes high-pressure gas cavity, low-pressure gas cavity, coil, piston, oil cavity, wire and piston valve;Control system includes helicopter landing gear, magnetorheological buffer, sensor, main controller, current driver and hall element.Control method includes: the height and fuselage attitude of helicopter and the data of buffer damping force are measured by sensor, and are transmitted to main controller;Main controller calculates the current required for coil in the process of helicopter landing;Main controller outputs PWM wave to current driver, and current driver outputs actual current to coil to change its damping force;Meanwhile, actual current is sensed by hall element and is fed back to main controller, and main controller tracks actual current by adaptive control algorithm.The application structure is simple and can adjust damping force in real time according to the change of helicopter attitude, can effectively reduce the vibration of helicopter when landing, so as to increase the stability and safety of helicopter when landing.

Description

Technical Field

[0001] This invention belongs to the field of helicopter control technology, and in particular to a helicopter landing gear magnetorheological damper and a magnetorheological vibration reduction control system and method. Background Technology

[0002] During aircraft landing, the impact of the aircraft relative to the ground and the collisions encountered while moving on uneven airport surfaces are primarily absorbed by the aircraft's landing gear damping system. The core of damping lies in effectively dissipating the aircraft's kinetic energy within the damping system. The landing gear damping system mainly consists of two parts: tires and shock absorbers. There are various types of landing gear shock absorbers, including steel spring shock absorbers, rubber spring shock absorbers, air shock absorbers, hybrid air-oil shock absorbers, and all-hydraulic shock absorbers. When designing landing gear shock absorbers, it is essential not only to meet the requirements of absorbing the impact energy during landing but also to consider how to more effectively reduce the load during taxiing, which is also an important design consideration.

[0003] Currently, traditional dual-chamber hydropneumatic shock absorbers face multiple requirements: they not only need to control the load during normal landing but also possess good full-maneuverability to prevent ground resonance. Furthermore, the shock absorber must be able to absorb energy during a crash landing and provide stable control in terms of load and travel. However, existing designs often cannot adjust accordingly to changes in the helicopter's fuselage attitude, which places higher demands on their performance.

[0004] Magnetorheological dampers offer advantages such as adjustable damping force, rapid response, and simple structure, making them suitable for vibration reduction design in helicopter landing gear. By adjusting the damping force according to changes in helicopter altitude, attitude, and damper force, the damping force can be effectively compensated, allowing the landing gear to adapt to different crash altitudes and attitudes. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the prior art by providing a magnetorheological damper for helicopter landing gear and a magnetorheological vibration reduction control system and method.

[0006] The technical solution to achieve the objective of this invention is as follows: On one hand, a magnetorheological damper for helicopter landing gear is provided. The magnetorheological damper includes a high-pressure air chamber, a low-pressure air chamber, a coil, a piston, an oil chamber, a wire, and a piston valve. The low-pressure air chamber is located on the left side of the high-pressure air chamber. The piston is filled with the low-pressure air chamber on its right side and with the oil chamber on its left side. The piston has multiple piston valves and a coil. The oil chamber is filled with a magnetorheological fluid. The wire is directly connected to the coil and is used to change the current in the coil, thereby changing the magnetic field inside the damper and thus changing the magnitude of the damping force.

[0007] Furthermore, the magnetorheological buffer is connected to the helicopter wheel.

[0008] Furthermore, the control system includes a magnetorheological buffer, a sensor module, a main controller, a current driver, and a Hall element;

[0009] The sensor module includes a helicopter altitude sensor, a helicopter fuselage attitude sensor, and a damping force sensor;

[0010] The helicopter altitude sensor, helicopter fuselage attitude sensor, and damping force sensor are used to collect helicopter altitude data, fuselage attitude data, and magnetorheological damper damping force data in real time during helicopter flight, and transmit the data to the main controller as input excitation for the main controller.

[0011] The main controller is used to calculate the magnitude of the current that the current driver needs to apply to the coil during the helicopter take-off and landing process based on the data collected by the sensor module and the mechanical model of the magnetorheological buffer; it is also used to output complementary ePWM1 and ePWM1-N waves to the current driver; and it is also used to track the actual current; the ePWM1 and ePWM1-N waves are a pair of PWM signals with opposite logic states.

[0012] The current driver is used to output the actual current to the coil in real time according to the output signal of the main controller to change its damping force.

[0013] The Hall element is used to sense the actual current and feed it back to the main controller.

[0014] Furthermore, the internal processes of the main controller include:

[0015] At the start of the program, the main controller executes the loop program once per preset control cycle;

[0016] In the control process within a single cycle, the signals from each sensor are first acquired, then the sensor signals are processed to obtain the control basis; then the desired current is calculated using a neural network; finally, the actual current is tracked by outputting PWM to the current driver.

[0017] Furthermore, the main controller tracks the actual current using an adaptive control algorithm.

[0018] Furthermore, the main controller is connected to the sensor module via an ADC chip.

[0019] Furthermore, the main controller communicates with the ADC chip via SPI.

[0020] On the other hand, a magnetorheological control method for helicopter landing gear is provided, the method comprising the following steps:

[0021] Step 1: The helicopter's altitude and fuselage attitude data, as well as the damping force data of the magnetorheological damper in the helicopter landing gear, are measured in real time by the helicopter altitude sensor, helicopter fuselage attitude sensor, and damping force sensor, and the data is transmitted to the main controller.

[0022] Step 2: Based on the above information and the mechanical model of the magnetorheological buffer, the main controller uses a neural network algorithm to calculate the magnitude of the current that the current driver needs to apply to the coil during the helicopter's takeoff and landing.

[0023] Step 3: The main controller outputs complementary ePWM1 and ePWM1-N waves to the current driver;

[0024] Step 4: The current driver outputs the actual current to the coil to change its damping force, thereby achieving control during the helicopter's takeoff and landing.

[0025] Step 5: The actual current is sensed by the Hall element and fed back to the main controller. The main controller tracks the actual current through an adaptive control algorithm.

[0026] Compared with the prior art, the significant advantages of this invention are:

[0027] (1) The present invention uses magnetorheological fluid instead of liquid in the traditional oil cavity. By utilizing the magnetorheological properties, the magnitude of damping force can be adjusted in real time during the take-off and landing of the helicopter.

[0028] (2) The present invention utilizes sensors, controllers and current drivers to form a control system, so that during the take-off and landing of the helicopter, the magnetorheological buffer can adjust the damping force in real time according to the helicopter's altitude and attitude, thereby effectively improving the buffering effect of the buffer.

[0029] (3) The present invention uses a neural network algorithm to calculate the magnitude and current curve of the current to be applied during the take-off and landing of the helicopter based on the input excitation, so that the control system can adjust the damping force according to the helicopter's altitude and attitude during the take-off and landing process, thereby ensuring the safety of the helicopter during the take-off and landing process.

[0030] The present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of a helicopter landing gear magnetorheological buffer in one embodiment.

[0032] Figure 2 This is a schematic diagram of the installation of a helicopter landing gear magnetorheological damper in one embodiment.

[0033] Figure 3This is a schematic diagram of a helicopter landing gear magnetorheological vibration reduction control system in one embodiment.

[0034] Figure 4 This is a schematic diagram of the control principle in the magnetorheological vibration reduction control system for helicopter landing gear in one embodiment.

[0035] Figure 5 This is a flowchart of the internal program of the AM623 main controller in the magnetorheological vibration reduction control system of a helicopter landing gear in one embodiment.

[0036] Figure 6 This is a schematic diagram illustrating the principle of the neural network algorithm in the magnetorheological vibration reduction control system for helicopter landing gear in one embodiment. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0038] In one embodiment, combined Figure 1 A magnetorheological damper for helicopter landing gear is provided. The magnetorheological damper includes a high-pressure air chamber 1, a low-pressure air chamber 2, a coil 3, a piston 4, an oil chamber 5, a wire 6, and a piston valve 7. The low-pressure air chamber 2 is located on the left side of the high-pressure air chamber 1. The low-pressure air chamber 2 is filled on the right side of the piston 4, and the oil chamber 5 is filled on the left side. The piston 4 has multiple piston valves 7 and coils 3. The oil chamber 5 is filled with magnetorheological fluid. The wire 6 is directly connected to the coil 3 and is used to change the current in the coil 3, thereby changing the magnetic field inside the damper and thus changing the damping force.

[0039] In some embodiments, combined with Figure 2 The magnetorheological damper mounting components include a helicopter wheel 9, a magnetorheological damper 8, a take-up and take-down device 10, and a magnetorheological coil wire 11. The magnetorheological damper 8 is connected to the helicopter wheel 9 and provides a buffering function during helicopter take-off and landing.

[0040] In one embodiment, combined Figure 3 and Figure 4 A magnetorheological control system for helicopter landing gear is provided, including a magnetorheological buffer, a sensor module, a main controller, a current driver, and a Hall element;

[0041] The sensor module includes a helicopter altitude sensor, a helicopter fuselage attitude sensor, and a damping force sensor;

[0042] The helicopter altitude sensor, helicopter fuselage attitude sensor, and damping force sensor are used to collect helicopter altitude data, fuselage attitude data, and magnetorheological damper damping force data in real time during helicopter flight, and transmit the data to the main controller as input excitation for the main controller.

[0043] The main controller is used to calculate the magnitude of the current that the current driver needs to apply to the coil during the helicopter take-off and landing process based on the data collected by the sensor module and the mechanical model of the magnetorheological buffer; it is also used to output complementary ePWM1 and ePWM1-N waves to the current driver; and it is also used to track the actual current; the ePWM1 and ePWM1-N waves are a pair of PWM signals with opposite logic states.

[0044] Here, PWM stands for Pulse Width Modulation, which is a pulse waveform with a variable duty cycle. Pulse Width Modulation is a method of digitally encoding analog signal levels. By using a high-resolution counter, the duty cycle of a square wave is modulated to encode the level of a specific analog signal.

[0045] The current driver is used to output the actual current to the coil in real time according to the output signal of the main controller to change its damping force.

[0046] Here, a motor driver is a key device used to control and manage the operation of an electric motor. It is widely used in various fields, including industrial production, transportation, and household appliances. Through a motor driver, users can precisely control parameters such as the motor's speed, torque, and power output, achieving high-efficiency, low-noise, and stable operation.

[0047] The Hall element is used to sense the actual current and feed it back to the main controller.

[0048] Here, a Hall element is a magnetic field sensor that utilizes the Hall effect and is widely used to detect magnetic fields and their changes. Its working principle is that when a magnetic field acts on charge carriers in a conductive metal or semiconductor, a transverse voltage difference is generated; this is the manifestation of the Hall effect.

[0049] Preferably, in some embodiments, combined with Figure 5 The internal processes of the main controller include:

[0050] At the start of the program, the main controller executes the loop program once per preset control cycle (e.g., 0.5ms).

[0051] In the control process within a single cycle, the signals from each sensor are first acquired, then the sensor signals are processed to obtain the control basis; then the desired current is calculated using a neural network; finally, the actual current is tracked by outputting PWM to the current driver.

[0052] Preferably, in some embodiments, the main controller uses a neural network algorithm to calculate the amount of current that the current driver needs to apply to the coil during helicopter takeoff and landing. Here, neural networks are an important algorithm in the field of machine learning. Inspired by the structure of the human brain, they simulate the organizational structure of the human brain's nervous system to process complex data patterns in a highly flexible manner, and are widely used in many cutting-edge technology fields such as image recognition, speech processing, natural language understanding, recommendation systems, and autonomous driving.

[0053] Combination Figure 6 The principle of neural network algorithms is that neural networks distinguish the importance of different information by assigning different weight values ​​to the input information. During model training, by adjusting the corresponding weights of the linear function, the weights of valuable information are increased, while the weights of other less valuable information are decreased, thereby calculating the required current value of the magnetorheological buffer in real time and accurately.

[0054] Preferably, in some embodiments, the main controller tracks the actual current using an adaptive control algorithm.

[0055] Here, the type of adaptive control algorithm is not limited. Adaptive control algorithms are a class of control methods used to handle uncertainties and changes in dynamic systems. These algorithms can automatically adjust the control strategy when system parameters change or external disturbances affect system performance, thereby ensuring system stability and performance.

[0056] Preferably, in some embodiments, the main controller is an AM623 and the current driver is a DRV8262-Q1.

[0057] Preferably, in some embodiments, the main controller is connected to the sensor module via an ADC chip.

[0058] Preferably, in some embodiments, the main controller communicates with the ADC chip via SPI.

[0059] In one embodiment, a magnetorheological control method for helicopter landing gear is provided, the method comprising the following steps:

[0060] Step 1: The helicopter's altitude and fuselage attitude data, as well as the damping force data of the magnetorheological damper in the helicopter landing gear, are measured in real time by the helicopter altitude sensor, helicopter fuselage attitude sensor, and damping force sensor, and the data is transmitted to the main controller.

[0061] Step 2: Based on the above information and the mechanical model of the magnetorheological buffer, the main controller uses a neural network algorithm to calculate the magnitude of the current that the current driver needs to apply to the coil during the helicopter's takeoff and landing.

[0062] Step 3: The main controller outputs complementary ePWM1 and ePWM1-N waves to the current driver;

[0063] Step 4: The current driver outputs the actual current to the coil to change its damping force, thereby achieving control during the helicopter's takeoff and landing.

[0064] Step 5: The actual current is sensed by the Hall element and fed back to the main controller. The main controller tracks the actual current through an adaptive control algorithm.

[0065] The present invention has a simple structure and can adjust the damping force in real time according to the changes in the helicopter's attitude, which can effectively reduce the vibration of the helicopter during takeoff and landing, thereby increasing the stability and safety of the helicopter during takeoff and landing.

[0066] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention without departing from its spirit and scope should be included within the protection scope of the present invention.

Claims

1. A magnetorheological control system for helicopter landing gear, characterized in that, The control system includes a magnetorheological buffer, a sensor module, a main controller, a current driver, and a Hall element; The magnetorheological damper includes a high-pressure air chamber (1), a low-pressure air chamber (2), a coil (3), a piston (4), an oil chamber (5), a wire (6), and a piston valve (7); the low-pressure air chamber (2) is located on the left side of the high-pressure air chamber (1); the low-pressure air chamber (2) is filled on the right side of the piston (4), and the oil chamber (5) is filled on the left side; the piston (4) has multiple piston valves (7) and coils (3); the oil chamber (5) is filled with magnetorheological fluid; the wire (6) is directly connected to the coil (3) and is used to change the current in the coil (3), thereby changing the magnetic field inside the damper and thus changing the damping force. The magnetorheological damper is connected to the helicopter wheel; The sensor module includes a helicopter altitude sensor, a helicopter fuselage attitude sensor, and a damping force sensor; The helicopter altitude sensor, helicopter fuselage attitude sensor, and damping force sensor are used to collect helicopter altitude data, fuselage attitude data, and magnetorheological damper damping force data in real time during helicopter flight, and transmit the data to the main controller as input excitation for the main controller. The main controller is used to calculate the magnitude of the current that the current driver needs to apply to the coil during the helicopter take-off and landing process based on the data collected by the sensor module and the mechanical model of the magnetorheological buffer; it is also used to output complementary ePWM1 and ePWM1-N waves to the current driver; and it is also used to track the actual current; the ePWM1 and ePWM1-N waves are a pair of PWM signals with opposite logic states. The current driver is used to output the actual current to the coil in real time according to the output signal of the main controller to change its damping force. The Hall element is used to sense the actual current and feed it back to the main controller.

2. The helicopter landing gear magnetorheological control system according to claim 1, characterized in that, The internal processes of the main controller include: At the start of the program, the main controller executes the loop program once per preset control cycle; In the control process within a single cycle, the signals from each sensor are first acquired, then the sensor signals are processed to obtain the control basis; then the desired current is calculated using a neural network; finally, the actual current is tracked by outputting PWM to the current driver.

3. The helicopter landing gear magnetorheological control system according to claim 1, characterized in that, The main controller tracks the actual current using an adaptive control algorithm.

4. The helicopter landing gear magnetorheological control system according to claim 1, characterized in that, The main controller is model AM623, and the current driver is model DRV8262-Q1.

5. The helicopter landing gear magnetorheological control system according to claim 1, characterized in that, The main controller is connected to the sensor module via an ADC chip.

6. The helicopter landing gear magnetorheological control system according to claim 5, characterized in that, The main controller communicates with the ADC chip via SPI.

7. A helicopter landing gear magnetorheological control method based on the control system described in any one of claims 1 to 6, characterized in that, The method includes the following steps: Step 1: The helicopter's altitude and fuselage attitude data, as well as the damping force data of the magnetorheological damper in the helicopter landing gear, are measured in real time by the helicopter altitude sensor, helicopter fuselage attitude sensor, and damping force sensor, and the data is transmitted to the main controller. Step 2: Based on the above information and the mechanical model of the magnetorheological buffer, the main controller uses a neural network algorithm to calculate the magnitude of the current that the current driver needs to apply to the coil during the helicopter's takeoff and landing. Step 3: The main controller outputs complementary ePWM1 and ePWM1-N waves to the current driver; Step 4: The current driver outputs the actual current to the coil to change its damping force, thereby achieving control during the helicopter's takeoff and landing. Step 5: The actual current is sensed by the Hall element and fed back to the main controller. The main controller tracks the actual current through an adaptive control algorithm.

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