Undercarriage capable of actively inhibiting ground resonance and control method and system thereof

Abstract

The invention provides an undercarriage capable of actively inhibiting ground resonance and a control method and system thereof. In the undercarriage, a magnetoelectric device and a laser displacement sensor are arranged on an outer cylinder of a buffer; the permanent magnet throttle valve is arranged at the upper part of a piston rod of the buffer; the sensing device is arranged on a tire; the magnetoelectric device is electrically connected with an aircraft power supply through the direct current conversion device; the sensing device, the laser displacement sensor and the direct current conversion device are all connected with the controller; the magnetoelectric device is used for generating high-frequency alternating induction electromagnetism under the action of the direct current conversion device; the permanent magnet throttle valve generates a real-time dynamic load under the electromagnetic action of the magnetoelectric device; the laser displacement sensor is used for collecting the actual elongation of the undercarriage buffer; the sensing device is used for collecting the actual compression amount of the tire. According to the invention, the capability of preventing ground resonance of the helicopter can be greatly provided, autonomous adjustment can be carried out on different landing and takeoff environments, aircraft postures, tire vibration, special conditions and the like, the flight burden can be greatly reduced, and the takeoff and landing quality of the helicopter is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of helicopter landing gear design, and in particular relates to a landing gear capable of actively suppressing ground resonance and a control method and system thereof. Background Art

[0002] Due to its special rotor structure, helicopters can take off and land vertically, and the small rotor rotation radius allows them to take off and land in a limited space. This is an important feature that distinguishes helicopters from fixed-wing aircraft. It is also because helicopters have important excitation sources such as rotors and transmissions that the speed will inevitably approach the resonant frequency of the helicopter during the operation from zero to the operating speed, which leads to the risk of ground resonance of the helicopter. With the development of technology, helicopters are constantly evolving into electric and intelligent urban flying vehicles, and the landing and take-off environment is becoming more and more complex. Helicopters have put forward higher and higher requirements for ground resonance. Preventing ground resonance is a very important requirement in the landing and take-off process of helicopters. It is closely related to the flight safety of helicopters and is the first line of defense to protect the lives of pilots.

[0003] In the traditional helicopter design process, the requirements for preventing ground resonance are mainly met by matching the appropriate helicopter stiffness and damping. Other important indicators are often given priority in the design process, resulting in fewer design adjustments for preventing ground resonance. In addition, since the tires that are in direct contact with the ground have a smaller stiffness, during actual takeoff and landing, the tires often produce greater vibrations, causing the landing gear buffers to not work. Summary of the invention

[0004] In order to solve the technical problem that the design adjustment amount for preventing ground resonance in the prior art is small, the tire will produce large vibration and cause the landing gear buffer to not work, the present invention provides a landing gear that actively suppresses ground resonance and a control method and system thereof, which is of great significance for preventing ground resonance during helicopter takeoff and landing, absorbing landing crash energy, and ensuring taxiing stability. The technical solution is as follows:

[0005] In a first aspect, a landing gear for actively suppressing ground resonance is provided, comprising: a magnetoelectric device 2, a permanent magnet throttle valve 3, a tire 6, a sensor device 7, and a laser displacement sensor 8;

[0006] The magnetoelectric device 2 and the laser displacement sensor 8 are arranged on the outer cylinder of the buffer; the permanent magnet throttle valve 3 is arranged on the upper part of the piston rod of the buffer, and the sensor device 7 is arranged on the tire 6; the magnetoelectric device 2 is electrically connected to the aircraft power supply through a DC conversion device, and the sensor device 7, the laser displacement sensor 8, and the DC conversion device are all connected to the controller; the magnetoelectric device 2 is used to generate high-frequency alternating induction electromagnetic under the action of the DC conversion device; the permanent magnet throttle valve 3 generates real-time dynamic load under the electromagnetic action of the magnetoelectric device 2; the laser displacement sensor 8 is used to collect the actual extension of the landing gear buffer; the sensor device 7 is used to collect the actual compression of the tire.

[0007] Optionally, the DC conversion device includes: a power supply and a current converter, the 48V power supply is electrically connected to the aircraft power supply, the 48V power supply is electrically connected to the magnetoelectric device 2 through the current converter, the aircraft power supply provides electrical energy to the 48V power supply, and the current converter provides the electrical energy to the magnetoelectric device 2.

[0008] In the present invention, a separate power supply is provided for the magnetoelectric device 2, which does not occupy the power supply of the aircraft itself.

[0009] Optionally, the magnetoelectric device 2 includes: an inner insulating sleeve and an outer insulating sleeve, and a magnetoelectric coil located therebetween.

[0010] Optionally, the sensing device 7 comprises: a pressure-variable layer arranged on the inner side of the tire and a conductive layer arranged on the outer side of the tire.

[0011] In a second aspect, a control method for a landing gear that actively suppresses ground resonance is provided, which is used for any landing gear described in the first aspect, and the method comprises:

[0012] Step 1: When the sensor device 7 detects that the aircraft has touched the ground, the controller determines the target load that needs to be applied to ensure the aircraft's attitude is stable;

[0013] Step 2, the controller controls the DC conversion device to drive the magnetoelectric device 2 to apply a target load to the permanent magnet throttle valve 3, so that the length of the landing gear buffer changes;

[0014] Step 3: When the preset conditions are met, stop applying the target load.

[0015] Optionally, in step 1, when the sensing device 7 detects that the aircraft has touched the ground, the laser displacement sensor 8 collects the actual extension L2 of the landing gear buffer, and the sensing device 7 collects the actual compression S2 of the tire. The laser displacement sensor 8 and the sensing device 7 send the collected data to the controller; the controller obtains the rotor lift and the aircraft weight and calculates the theoretical extension L1 of the landing gear buffer and the theoretical compression S1 of the tire in the current state according to the landing gear static pressure curve by interpolation calculation; the controller calculates the target load F that needs to be applied to ensure the stability of the aircraft attitude based on L1, S1, L2, and S2t and the overall extension difference of the landing gear R t ;

[0016] R t =K*L2-S2-(K*L1-S1), where K is the landing gear force transmission coefficient and R is the overall extension difference of the landing gear. t is positive, the target load is acting in the positive Z direction (the z direction is perpendicular to the heading); R t If it is negative, the target load acts in the negative Z direction, F t =f(-R t / K+L2)-f(L2),F t is the target load at time t, and f is the load difference function.

[0017] Optionally, in step 2, the controller sends a load application instruction to the DC conversion device, the load application instruction carries the current magnitude and current direction, and the DC conversion device drives the magnetoelectric device 2 to apply the target load F to the permanent magnet throttle valve 3. t , the action time is δt, at which time the length of the landing gear buffer changes.

[0018] Optionally, in step 3, when the controller detects that any of the following conditions is met, the controller stops applying the target load, otherwise, the above steps 1 and 2 are repeated:

[0019] Condition 1: Landing gear overall extension difference R t The absolute value is less than the threshold (for example, 5mm),

[0020] Condition 2: The tire is off the ground.

[0021] Condition 3: The rotor lift is 0.

[0022] In a third aspect, a system for actively suppressing ground resonance is provided, comprising a landing gear for actively suppressing ground resonance as described in any one of the first aspects, as well as a DC conversion device, an aircraft power supply and a controller.

[0023] The beneficial effects of the present invention are at least:

[0024] This scheme aims to actively suppress the ground resonance of the helicopter. In addition, when the helicopter is parked on the ground, this scheme can achieve the lifting and kneeling of the helicopter by applying electromagnetic force to the permanent magnet throttle valve, which is convenient for loading cargo; when the helicopter is taxiing on the ground, this scheme can filter the uneven ground load by applying electromagnetic force to the permanent magnet throttle valve to improve driving comfort; when the helicopter crashes, this scheme can assist in absorbing the crash energy by applying electromagnetic force to the permanent magnet throttle valve. It can be seen that this scheme is particularly important for preventing ground resonance during helicopter takeoff and landing, absorbing landing crash energy, and ensuring taxiing stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the assembly of the present invention;

[0026] Figure 2 This is the schematic diagram of the landing gear;

[0027] Figure 3 is a schematic diagram of the sensing device;

[0028] Figure 4 Schematic diagram of the magnetoelectric device.

[0029] Among them, 1-oil chamber, 2-magnetoelectric device, 3-permanent magnet throttle valve, 4-floating piston, 5-air chamber, 6-tire, 7-sensing device, 8-laser displacement sensor. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below through specific implementation modes and drawings.

[0031] See also Figure 1 and Figure 2 The active ground resonance suppression landing gear provided by an embodiment of the present invention comprises a magnetoelectric device 2, a permanent magnet throttle valve 3, a floating piston 4, a tire 6 and a sensor device 7; the aircraft power supply, controller and DC conversion device are arranged on the aircraft, and can dynamically output instructions to the magnetoelectric device 2; the magnetoelectric device 2 is arranged on the outer cylinder of the landing gear, and can generate high-frequency alternating induction electromagnetic; the permanent magnet throttle valve 3 is arranged on the upper part of the piston rod, and can generate real-time dynamic load under the action of induction electromagnetic; the sensor device 7 is arranged on the tire 6, and can detect whether the tire touches the ground and dynamically monitor the compression of the tire; the laser displacement sensor 8 is arranged at the lower part of the magnetoelectric device 2, and can dynamically detect the displacement of the piston rod. The floating piston 4 is arranged inside the landing gear, and is used to separate the oil chamber 1 and the air chamber 5, the oil chamber 1 is located inside the outer cylinder, and the air chamber 5 is located inside the piston rod.

[0032] In one embodiment, the DC conversion device includes: a power supply and a current converter, the 48V power supply is electrically connected to the aircraft power supply, the 48V power supply is electrically connected to the magnetoelectric device 2 through the current converter, the aircraft power supply provides electrical energy to the 48V power supply, and the current converter provides the electrical energy to the magnetoelectric device 2.

[0033] In one embodiment, see Figure 4 The magnetoelectric device 2 includes: an inner insulating sleeve and an outer insulating sleeve, and a magnetoelectric coil located therebetween.

[0034] In one embodiment, see Figure 3 The sensing device 7 includes: a pressure-changing layer arranged on the inner side of the tire and a conductive layer arranged on the outer side of the tire.

[0035] When the landing gear is working normally, the landing energy is absorbed by the gas spring force and the oil damping force generated by the throttle valve. The gas provides appropriate stiffness to ensure that the helicopter does not have ground resonance under normal circumstances. The oil damping force provides a certain damping force to consume the tiny vibrations generated during the operation of the helicopter, preventing the vibration from diverging and causing the whole machine to have ground resonance. The specific implementation process is as follows:

[0036] Step 1: At time t, when the sensor device 7 detects that the aircraft has touched the ground, the laser displacement sensor 8 collects the actual extension L2 of the landing gear buffer, and the sensor device 7 collects the actual compression S2 of the tire. The laser displacement sensor 8 and the sensor device 7 send the collected data to the controller. The controller obtains the rotor lift and the weight of the aircraft and calculates the theoretical extension L1 of the landing gear buffer and the theoretical compression S1 of the tire in the current state by interpolation calculation according to the landing gear static pressure curve. The controller calculates the target load F that needs to be applied to ensure the stability of the aircraft attitude based on L1, S1, L2, and S2. t and the overall extension difference of the landing gear R t ; R t =K*L2-S2-(K*L1-S1), where K is the landing gear force transmission coefficient and R is the overall extension difference of the landing gear. t is positive, the target load is acting in the positive Z direction (the z direction is perpendicular to the heading); R t If F is negative, the target load acts in the negative Z direction. t =f(-R t / K+L2)-f(L2),F t is the target load at time t, and f() is the load difference function.

[0037] The specific process of calculating the theoretical extension of the landing gear buffer and the theoretical compression of the tire in the current state by interpolation calculation according to the landing gear static pressure curve can refer to the relevant technology, for example, according to the following formula:

[0038] The theoretical elongation L is: L = fl (Mg-F L ),

[0039] Theoretical compression S = fs(Mg-F L ), where M is the weight of the aircraft, F L is the rotor, fl and fs are the extension difference function and compression difference function respectively.

[0040] Step 2: The magnetoelectric device 2 generates a high-frequency alternating induction electromagnetic under the action of the DC conversion device; the permanent magnet throttle valve 3 generates a real-time dynamic load under the electromagnetic action of the magnetoelectric device 2; at time t, the controller sends a load application instruction to the DC conversion device, and the load application instruction carries the current magnitude and current direction, and the DC conversion device drives the magnetoelectric device 2 to apply the target load F to the permanent magnet throttle valve 3. t , the action time is δt, at which time the length of the landing gear buffer changes;

[0041] Step 3: When the controller detects that any of the following conditions is met, the controller stops applying the target load; otherwise, the above steps 1 and 2 are repeated.

[0042] Condition 1: Landing gear overall extension difference R t The absolute value is less than the threshold (for example, 5mm),

[0043] Condition 2: The tire is off the ground.

[0044] Condition 3: The rotor lift is 0.

[0045] When any of the above conditions is met, the stability of the aircraft can be ensured and the possibility of ground resonance can be eliminated.

[0046] For example, in one embodiment, the force transmission coefficient K is 1. Aircraft take-off process:

[0047] 1. At time t, the tire touches the ground and the rotor lift is 15000N. The aircraft weight is 8500Kg. The difference calculation shows that the buffer extension L1 should be 200mm and the tire compression S1 is 30mm. The sensor monitors that L2 is 180mm and S2 is 40mm. Calculate R t = -30mm, the target load direction is negative, the difference calculation F t Equal to 5000N;

[0048] 2. The controller controls the DC conversion device to generate the corresponding current, and the electromagnetic device to generate the corresponding electromagnetic. t Acts on the permanent magnet throttle valve for a period of time δt.

[0049] 3. At the time t+δt, the rotor lift is 16000N. At this time, the aircraft weight is 8500Kg. The difference calculation buffer extension L1 should be 201mm, and the tire compression S1 is 29mm. The sensor monitors that L2 is 185mm and S2 is 41mm. Calculate R t = -28mm, the target load direction is negative, the difference calculation F t Equal to 4800N;

[0050] 4. The controller controls the DC conversion device to generate the corresponding current, and the electromagnetic device to generate the corresponding electromagnetic t Acts on the permanent magnet throttle valve for a period of time δt.

[0051] 5. Until time t1, the tire is detected to be off the ground and the program stops.

[0052] For example, in one embodiment, the force transmission coefficient K is 1. Aircraft landing process:

[0053] 1. At time t, the tire touches the ground and the rotor lift is 15000N. The aircraft weight is 8500Kg. The difference calculation shows that the buffer extension L1 should be 200mm and the tire compression S1 is 30mm. The sensor monitors that L2 is 220mm and S2 is 20mm. Calculate R t Equal to 30mm, the target load direction is positive, the difference calculation F t Equal to 5000N;

[0054] 2. The controller controls the DC conversion device to generate the corresponding current, and the electromagnetic device to generate the corresponding electromagnetic. t Acts on the permanent magnet throttle valve for a period of time δt.

[0055] 3. At the time t+δt, the rotor lift is 14000N. At this time, the aircraft weight is 8500Kg. The difference calculation buffer extension L1 should be 199mm, and the tire compression S1 is 31mm. The sensor monitors that L2 is 215mm and S2 is 22mm. Calculate R t Equal to 25mm, the target load direction is positive, the difference calculation F t Equal to 4500N;

[0056] 4. The controller controls the DC conversion device to generate the corresponding current, and the electromagnetic device to generate the corresponding electromagnetic t Acts on the permanent magnet throttle valve for a period of time δt.

[0057] 5. Until time t1, the rotor lift is detected to be 0 and the program stops.

[0058] The present invention adopts the coupling of electromagnetic force, oil damping force and gas spring force to maximize the efficiency of the buffer in preventing ground resonance; the magnetoelectric device is designed on the outer cylinder of the landing gear, and the permanent magnet throttle valve is designed on the upper end of the piston rod, which does not affect the normal working performance of the buffer; the magnetoelectric device adopted in the present invention has the outstanding advantages of fast response speed and large adjustment margin.

[0059] The use of the device of the present invention can greatly improve the ability of the helicopter to prevent ground resonance, and can autonomously adjust to different landing and take-off environments, aircraft attitudes, tire vibrations and special situations, greatly reducing the flight burden and improving the take-off and landing quality of the helicopter.

[0060] The above only expresses the implementation mode of the present invention, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. In addition, the parts not detailed in the present invention are all conventional technologies.

Claims

1. A landing gear for actively suppressing ground resonance, characterized in that: include: A magnetoelectric device (2), a permanent magnet throttle valve (3), a tire (6), a sensor device (7), and a laser displacement sensor (8); The magnetoelectric device (2) and the laser displacement sensor (8) are arranged on the outer cylinder of the buffer; the permanent magnet throttle valve (3) is arranged on the upper part of the piston rod of the buffer, and the sensor device (7) is arranged on the tire (6); the magnetoelectric device (2) is electrically connected to the aircraft power supply through a DC conversion device, and the sensor device (7), the laser displacement sensor (8) and the DC conversion device are all connected to a controller; the magnetoelectric device (2) is used to generate high-frequency alternating induction electromagnetic under the action of the DC conversion device; the permanent magnet throttle valve (3) generates real-time dynamic load under the electromagnetic action of the magnetoelectric device (2); the laser displacement sensor (8) is used to collect the actual extension of the landing gear buffer; and the sensor device (7) is used to collect the actual compression of the tire.

2. The active ground resonance suppression landing gear according to claim 1, characterized in that: The DC conversion device comprises: a power supply and a current converter, the 48V power supply is electrically connected to the aircraft power supply, the 48V power supply is electrically connected to the magnetoelectric device (2) through the current converter, the aircraft power supply provides electrical energy to the 48V power supply, and the current converter provides the electrical energy to the magnetoelectric device (2).

3. The active ground resonance suppression landing gear according to claim 1, characterized in that: The magnetoelectric device (2) comprises an inner insulating sleeve and an outer insulating sleeve, and a magnetoelectric coil located therebetween.

4. The active ground resonance suppression landing gear according to claim 1, characterized in that: The sensing device (7) comprises: a pressure-changing layer arranged on the inner side of the tire and a conductive layer arranged on the outer side of the tire.

5. A method for controlling a landing gear for actively suppressing ground resonance, characterized in that: For the landing gear according to any one of claims 1 to 4, the method comprises: Step 1: When the sensing device (7) detects that the aircraft has touched the ground, the controller determines the target load that needs to be applied to ensure that the aircraft has a stable attitude; Step 2: The controller controls the DC conversion device to drive the magnetoelectric device (2) to apply a target load to the permanent magnet throttle valve (3), so that the length of the landing gear buffer changes; Step 3: When the preset conditions are met, stop applying the target load.

6. The method according to claim 5, characterized in that In step 1, when the sensing device (7) detects that the aircraft has touched the ground, the laser displacement sensor (8) collects the actual extension L2 of the landing gear buffer, and the sensing device (7) collects the actual compression S2 of the tire. The laser displacement sensor (8) and the sensing device (7) send the collected data to the controller; the controller obtains the rotor lift and the weight of the aircraft and calculates the theoretical extension L1 of the landing gear buffer and the theoretical compression S1 of the tire in the current state by interpolation calculation according to the landing gear static pressure curve; the controller calculates the target load F that needs to be applied to ensure the stability of the aircraft attitude based on L1, S1, L2, and S2 t and the overall extension difference of the landing gear R t ; R t =K*L2-S2-(K*L1-S1), where K is the landing gear force transmission coefficient and R is the overall extension difference of the landing gear. t is positive, the target load acts in the positive direction of Z; R t If it is negative, the target load acts in the negative Z direction, F t =f(-R t / K+L2)-f(L2),F t is the target load at time t, and f is the load difference function.

7. The method according to claim 6, characterized in that In step 2, the controller sends a load application instruction to the DC conversion device, the load application instruction carries the current magnitude and current direction, and the DC conversion device drives the magnetoelectric device (2) to apply the target load F to the permanent magnet throttle valve (3). t , the action time is δt, at which time the length of the landing gear buffer changes.

8. The method according to claim 7, characterized in that In step 3, the controller stops applying the target load when it detects that any of the following conditions are met. Otherwise, the above steps 1 and 2 are repeated: Condition 1: Landing gear overall extension difference R t The absolute value is less than the threshold. Condition 2: The tire is off the ground. Condition 3: The rotor lift is 0.

9. A system for actively suppressing ground resonance, characterized in that: The invention comprises a landing gear for actively suppressing ground resonance as described in any one of claims 1 to 4, as well as a DC conversion device, an aircraft power supply and a controller.

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