Helicopter undercarriage magneto-rheological buffer and magneto-rheological vibration reduction control system and method

Abstract

The invention discloses a magneto-rheological buffer of a helicopter undercarriage and a magneto-rheological vibration reduction control system and method. The magneto-rheological buffer comprises a high-pressure air cavity, a low-pressure air cavity, a coil, a piston, an oil cavity, a wire and a piston valve. The control system comprises a helicopter undercarriage, a magneto-rheological buffer, a sensor, a main controller, a current driver and a Hall element. The control method comprises the following steps: measuring data of the height and the body posture of the helicopter and the damping force of the buffer through the sensor, and transmitting the data to the main controller; the main controller calculates the current required by the coil in the rising and falling process of the helicopter; the main controller outputs PWM waves to the current driver, and the current driver outputs actual current to the coil to change the damping force of the coil; meanwhile, actual current is sensed through a Hall element and fed back to the main controller, and the main controller tracks the actual current through a self-adaptive control algorithm. The damping device is simple in structure, damping force can be adjusted in real time according to changes of the helicopter attitude, vibration of the helicopter during landing can be effectively reduced, and therefore the stability and safety of the helicopter during landing are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of helicopter control, in particular to a magnetorheological buffer of a helicopter landing gear and a magnetorheological vibration reduction control system and method. Background Art

[0002] When the aircraft lands, the impact of the aircraft relative to the ground and the collision encountered when moving on an uneven airport are mainly borne by the aircraft's landing gear buffer system. The core of buffering is to effectively dissipate the kinetic energy of the aircraft in the buffer system. The landing gear buffer system is mainly composed of two parts: tires and buffers. There are many types of landing gear buffers, including steel spring buffers, rubber spring buffers, air buffers, oil-air hybrid buffers, and full oil buffers. When designing a landing gear buffer, it is not only necessary 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] At present, traditional dual-chamber oil-pneumatic buffers face multiple requirements: not only do they need to control the load during normal landing, but they also need to have good full maneuverability characteristics to prevent ground resonance. In addition, the buffers need to be able to absorb the energy during crash landing and provide stable control in terms of load and travel. However, existing designs often cannot make corresponding adjustments according to changes in the helicopter fuselage attitude, which puts higher requirements on their performance.

[0004] Magnetorheological dampers have the advantages of adjustable damping force, rapid response and simple structure, and are suitable for use in the vibration reduction design of helicopter landing gear. By adjusting according to the changes in helicopter altitude, attitude and damping force of the damper, the damping force can be effectively compensated, so that the landing gear can adapt to different crash altitudes and different attitudes. Summary of the invention

[0005] The object of the present invention is to provide a magnetorheological buffer for helicopter landing gear and a magnetorheological vibration reduction control system and method in view of the problems existing in the above-mentioned prior art.

[0006] The technical solution to achieve the purpose of the present invention is as follows: on the one hand, a magnetorheological buffer for helicopter landing gear is provided, and the magnetorheological buffer 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 provided on the left side of the high-pressure air chamber; the low-pressure air chamber is filled on the right side of the piston, and the oil chamber is filled on the left side; there are multiple valves and coils on the piston; the interior of the oil chamber is filled with magnetorheological liquid; the wire is directly connected to the coil, and is used to change the current on the coil, thereby changing the magnetic field inside the buffer, thereby changing the damping force.

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

[0008] Further, 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 body attitude sensor and a damping force sensor;

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

[0011] The main controller is used to calculate the current size that the current driver needs to apply to the coil during the helicopter take-off and landing process according to 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; it is also used to track the actual current; the ePWM1 and ePWM1-N waves are a pair of PWM signals with mutually inverted logical 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 process of the main controller includes:

[0015] When the program starts, the main controller executes the cyclic program once per cycle according to the preset control cycle;

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

[0017] Furthermore, the main controller tracks the actual current through 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, using a helicopter altitude sensor, a helicopter fuselage attitude sensor and a damping force sensor to measure in real time the helicopter altitude and fuselage attitude data and the damping force data of the magnetorheological buffer in the helicopter landing gear during the flight of the helicopter, and transmit the data to a 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 current that the current driver needs to apply to the coil during the helicopter take-off and landing process;

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

[0024] Step 4, the current driver outputs actual current to the coil to change its damping force, thereby achieving control during the helicopter take-off and landing process;

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

[0026] Compared with the prior art, the present invention has the following significant advantages:

[0027] (1) The present invention uses magnetorheological fluid to replace the liquid in the traditional oil chamber, and utilizes the magnetorheological properties to adjust the damping force in real time during the take-off and landing process 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 process of the helicopter, the magnetorheological buffer can adjust the damping force in real time according to the height and attitude of the helicopter, thereby effectively improving the buffering effect of the buffer.

[0029] (3) The present invention uses a neural network algorithm to calculate the current size and current curve required to be applied during the helicopter take-off and landing process based on input excitation, so that the control system can ensure that the damping force is adjusted according to information such as the helicopter's height and posture 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 is further described in detail below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0032] Figure 2 The figure is a schematic diagram of the installation of a magnetorheological buffer for a helicopter landing gear in one embodiment.

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

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

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

[0036] Figure 6 The figure is a schematic diagram of the principle of a neural network algorithm in a magnetorheological vibration reduction control system for a helicopter landing gear in one embodiment. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0038] In one embodiment, in combination Figure 1 , provides a magnetorheological buffer for helicopter landing gear, the magnetorheological buffer comprising 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 provided 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; there are multiple valves and a coil 3 on the piston 4; the oil chamber 5 is filled with magnetorheological liquid; the wire 6 is directly connected to the coil 3, and is used to change the current on the coil 3, thereby changing the magnetic field inside the buffer, thereby changing the damping force.

[0039] In some embodiments, in combination Figure 2 The magnetorheological buffer installation components include a helicopter wheel 9, a magnetorheological buffer 8, a retracting device 10 and a magnetorheological coil wire 11. The magnetorheological buffer 8 is connected to the helicopter wheel 9 and plays a buffering function during the helicopter take-off and landing process.

[0040] In one embodiment, in combination Figure 3 and Figure 4 , provides a magnetorheological control system for helicopter landing gear, 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 body attitude sensor and a damping force sensor;

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

[0043] The main controller is used to calculate the current size that the current driver needs to apply to the coil during the helicopter take-off and landing process according to 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; it is also used to track the actual current; the ePWM1 and ePWM1-N waves are a pair of PWM signals with mutually inverted logical states;

[0044] Here, PWM is pulse width modulation, which is a pulse waveform with a variable duty cycle. Pulse width modulation is a method of digitally encoding the level of an analog signal. Through the use of 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, the motor driver is a key device used to control and manage the operation of the motor, and is widely used in various fields, including industrial production, transportation, household appliances, etc. Through the motor driver, users can accurately control the motor's speed, torque, power output and other parameters to achieve high efficiency, low noise, and good stability.

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

[0048] Here, the Hall element is a magnetic field sensor that uses 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 carriers in a conductive metal or semiconductor, a transverse voltage difference is generated, which is the manifestation of the Hall effect.

[0049] Preferably, in some embodiments, Figure 5 , the internal process of the main controller includes:

[0050] When the program starts, the main controller executes the cyclic program once per cycle according to the preset control cycle (such as 0.5ms, etc.);

[0051] In the control process within a single cycle, the sensor signals are first collected, and then processed to obtain the control basis; then the expected current is calculated using the 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 current size that the current driver needs to apply to the coil during the helicopter take-off and landing process. Here, neural network is an important algorithm in the field of machine learning. It is inspired by the structure of the human brain and simulates the organizational structure of the human brain nervous system to process complex data patterns in a highly flexible way. It is 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 the neural network algorithm is that the neural network distinguishes the importance of different information by assigning different weights to the input information. During the model training process, the corresponding weights of the linear function are adjusted to increase the weight of valuable information and reduce the weight of other information with lower value, so as to accurately calculate the current value required by the magnetorheological buffer in real time.

[0054] Preferably, in some embodiments, the main controller tracks the actual current through 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 deal with uncertainty 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 model of the main controller is AM623, and the model of the current driver is 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, using a helicopter altitude sensor, a helicopter fuselage attitude sensor and a damping force sensor to measure in real time the helicopter altitude and fuselage attitude data and the damping force data of the magnetorheological buffer in the helicopter landing gear during the flight of the helicopter, and transmit the data to a 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 current that the current driver needs to apply to the coil during the helicopter take-off and landing process;

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

[0063] Step 4, the current driver outputs actual current to the coil to change its damping force, thereby achieving control during the helicopter take-off and landing process;

[0064] Step 5, the actual current is sensed by the Hall element and fed back to the main controller, and 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 change of the helicopter's posture, and can effectively reduce the vibration of the helicopter during take-off and landing, thereby increasing the stability and safety of the helicopter during take-off and landing.

[0066] The above shows and describes 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 by the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A magnetorheological buffer for helicopter landing gear, characterized in that: The magnetorheological buffer comprises 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 provided 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; a plurality of valves and a coil (3) are provided on the piston (4); the interior of 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 magnitude of the current on the coil (3), thereby changing the magnetic field inside the buffer, and thus changing the magnitude of the damping force.

2. The helicopter landing gear magnetorheological buffer according to claim 1, characterized in that: The magnetorheological buffer is connected to the helicopter wheel.

3. A magnetorheological control system for helicopter landing gear based on the magnetorheological buffer according to claim 1, characterized in that: The control system includes a magnetorheological buffer, a sensor module, a main controller, a current driver and a Hall element; The sensor module includes a helicopter altitude sensor, a helicopter body attitude sensor and a damping force sensor; The helicopter altitude sensor, helicopter fuselage attitude sensor and damping force sensor are used to respectively collect the helicopter altitude data, fuselage attitude data and magnetorheological buffer damping force data in real time during the flight of the helicopter, and transmit the data to the main controller as input excitation of the main controller; The main controller is used to calculate the current size that the current driver needs to apply to the coil during the helicopter take-off and landing process according to 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; it is also used to track the actual current; the ePWM1 and ePWM1-N waves are a pair of PWM signals with mutually inverted logical 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.

4. The magnetorheological control system for helicopter landing gear according to claim 3, characterized in that: The internal process of the main controller includes: When the program starts, the main controller executes the cyclic program once per cycle according to the preset control cycle; In the control process within a single cycle, the sensor signals are first collected, and then processed to obtain the control basis; then the expected current is calculated using the neural network; finally, the actual current is tracked by outputting PWM to the current driver.

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

6. The magnetorheological control system for helicopter landing gear according to claim 3, characterized in that: The model of the main controller is AM623, and the model of the current driver is DRV8262-Q1.

7. The magnetorheological control system for helicopter landing gear according to claim 3, characterized in that: The main controller is connected to the sensor module via an ADC chip.

8. The magnetorheological control system for helicopter landing gear according to claim 7, characterized in that: The main controller communicates with the ADC chip via SPI.

9. A magnetorheological control method for helicopter landing gear based on the control system according to any one of claims 3 to 8, characterized in that: The method comprises the following steps: Step 1, using a helicopter altitude sensor, a helicopter fuselage attitude sensor and a damping force sensor to measure in real time the helicopter altitude and fuselage attitude data and the damping force data of the magnetorheological buffer in the helicopter landing gear during the flight of the helicopter, and transmit the data to a 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 current that the current driver needs to apply to the coil during the helicopter take-off and landing process; Step 3, the main controller outputs complementary ePWM1 and ePWM1-N waves to the current driver; Step 4, the current driver outputs actual current to the coil to change its damping force, thereby achieving control during the helicopter take-off and landing process; Step 5, the actual current is sensed by the Hall element and fed back to the main controller, and the main controller tracks the actual current through an adaptive control algorithm.

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