A system and method for controlling the landing of an unpowered passive adaptive landing gear

Abstract

The application discloses a kind of unloading passive self-adapting landing gear's landing control system and control method, system includes: controller and hydraulic source, and respectively being configured on each landing gear 1 set of adaptive control mechanism;In adaptive control mechanism, controller is electrically connected with electromagnetic valve and servo valve respectively, hydraulic source, electromagnetic valve and reversing valve are sequentially communicated, form control oil circuit;Reversing valve is communicated with servo valve by high-pressure oil circuit, servo valve is communicated with hydraulic lock by servo oil circuit;Hydraulic source is connected to electromagnetic valve, reversing valve, servo valve respectively;Unlocking mechanism is installed in the cavity of the stowing and releasing actuator.The technical scheme of the present application solves the existing control mode of helicopter landing, the response is not timely, it is easy to miss the rest period, and the required sensor type is more, the difficulty of hardware reliability requirement is greater, and the landing safety is poorer and other problems.

Description

TECHNICAL FIELD

[0001] The present application relates to, but is not limited to, the technical field of helicopter landing gear structure, and in particular to a landing control system and method for an empty passive adaptive landing gear. BACKGROUND

[0002] The difficulty of landing a helicopter in a sea environment is different from that in a land environment, which lies in the fact that the helicopter needs to be quickly landed in a short resting period (i.e. the angle between the ship surface and the sea level is within a certain angle) during the ship surface shaking process to ensure the stability of the fuselage. Taking the patent "shipborne helicopter adaptive landing gear landing simulation system" (patent number: CN109094817B) as an example, the scheme of this patent uses a laser radar, an inertial element, a six-dimensional force sensor, a laser ranging sensor and other components to measure the ship surface shaking state, determines the timing of the landing gear attitude lock according to the attitude position, force size and other measurement results, and the subsequent landing energy absorption process is consistent with the traditional landing gear.

[0003] The disadvantages of the active attitude adjustment adaptive landing through multiple sensor measurements lie in the high ship surface shaking frequency and the short resting period. The process from data measurement, analysis and processing to sending landing gear position command and completing the mechanism execution has system delay, which is easy to miss the resting period. In addition, the climate in the sea environment is harsh, and the more types of sensors required, the greater the difficulty of hardware reliability requirements. SUMMARY

[0004] The purpose of the present application is to solve the above problems. The present application provides a landing control system and method for an empty passive adaptive landing gear to solve the existing control method of helicopter landing. Due to the use of active attitude adjustment method, and due to the high ship surface shaking frequency and the short resting period, the response is not timely, which is easy to miss the resting period, and the types of sensors required are many, the difficulty of hardware reliability requirements is great, and the landing safety is poor.

[0005] The technical solution of the present application is as follows:

[0006] The present application provides a landing control system for an empty passive adaptive landing gear, which comprises a controller 1 and a hydraulic source 10, and one set of adaptive control mechanism arranged on each landing gear.

[0007] Each set of adaptive control mechanism comprises an electromagnetic valve 2, a reversing valve 3, a servo valve 4, a hydraulic lock 5, an unlocking mechanism 6, a retractable actuator 9 and a sensor.

[0008] The controller 1 is electrically connected with the electromagnetic valve 2 and the servo valve 4 respectively, the hydraulic source 10, the electromagnetic valve 2 and the reversing valve 3 are communicated in sequence to form a control oil circuit; the reversing valve 3 and the servo valve 4 are communicated through a high-pressure oil circuit, and the servo valve 4 and the hydraulic lock 5 are communicated through a servo oil circuit; the hydraulic source 10 is connected to the electromagnetic valve 2, the reversing valve 3 and the servo valve 4 respectively; the unlocking mechanism 6 is installed in the cavity of the retraction actuator 9.

[0009] Each set of the adaptive control mechanism is used for controlling opening of a control oil circuit in the adaptive control mechanism and connecting a servo oil circuit according to an instruction of the controller 1, so that the unlocking mechanism 6 is opened under the pressure of the hydraulic source 10, the piston rod of the retraction actuator 9 can be freely stretched or compressed, and the landing gear system enters an adaptive state.

[0010] Optionally, in the landing control system of the empty-load passive adaptive landing gear, each set of the adaptive control mechanism further comprises a sliding block lock 11 and a spring 12.

[0011] The retraction actuator 9 is externally provided with an extension nozzle and a retraction nozzle, the extension nozzle is connected with an oil inlet pipeline of the hydraulic lock 5, and the retraction nozzle is connected with an oil return pipeline of the hydraulic lock 5.

[0012] The retraction actuator 9 is provided with the sliding block lock 11 between the main body structure and the piston rod, the piston rod of the retraction actuator 9 is internally provided with the unlocking mechanism 6 at one end of a rodless cavity, and the unlocking mechanism is provided with the spring 12 between the unlocking mechanism and the piston rod; the unlocking mechanism 6 is provided with a clamping groove between the unlocking mechanism and a piston rod installation cavity, and the clamping groove is used for cooperating with the sliding block lock 11 to lock.

[0013] Optionally, in the landing control system of the empty-load passive adaptive landing gear, a locking mode of the piston rod in the retraction actuator 9 in an extension process is as follows:

[0014] When hydraulic oil enters the extension nozzle through the oil circuit of the hydraulic lock 5, the spring 12 is pushed to move the unlocking mechanism 6 until the sliding block lock 11 is embedded into the clamping groove of the unlocking mechanism 6, and the piston rod cannot be further lengthened through the limitation of the sliding block lock 11.

[0015] Optionally, in the landing control system of the empty-load passive adaptive landing gear, a locking mode of the piston rod in the retraction actuator 9 in a contraction process is as follows:

[0016] In the contraction process of the piston rod, the hydraulic oil enters the retraction nozzle through the oil circuit of the hydraulic lock 5, pushes the sliding block lock 11 and the piston rod to move to one side of the rodless cavity, and the sliding block lock 11 returns to the original position under the elastic force of the spring 12 to lock.

[0017] Optionally, in the landing control system of the empty passive adaptive landing gear as described above, the sensor comprises at least one of a displacement sensor 7 and a force sensor 8.

[0018] The displacement sensor 7 is installed on the piston rod of the retraction actuator 9, and the force sensor 8 is installed at the ground contact end of the landing gear.

[0019] Optionally, in the landing control system of the empty passive adaptive landing gear as described above,

[0020] The helicopter to be landed is provided with multiple landing gears, each of which is configured with a set of adaptive control mechanisms, and all the adaptive control mechanisms share the controller 1 and the hydraulic source 10.

[0021] The embodiment of the present application also provides a control method of the landing control system of the empty passive adaptive landing gear, which adopts the landing control system of the empty passive adaptive landing gear as described in any one of the above embodiments to perform a passive adaptive landing control method of the landing gear mechanism, and the passive adaptive landing control method comprises the following steps:

[0022] Step 1. During the landing descent of the machine body, the adaptive control mechanism on each landing gear is turned on, so that the piston rod of the retraction actuator 9 is freely stretched, and the landing gear enters an adaptive state;

[0023] Step 2. The landing gear that has contacted the ship is still passively adjusted in posture as the machine body descends, and the extension amount of the retraction actuator 9 is controlled through the controller 1;

[0024] Step 3. When the ship surface shakes and the landing gear that has contacted the ship is out of the contact state, the controller 1 connects the servo valve 4 to switch the oil circuit, the retraction actuator 9 enters a contraction state, so that the posture of the landing gear is lowered, thereby realizing the ship surface shaking following capability;

[0025] Step 4. After the last landing gear contacts the ground, the controller 1 controls the output of the electromagnetic valve 2 and the servo valve 4 based on the judgment of the extension stroke of all the retraction actuators 9 and the contact load, and the flow locking in the hydraulic lock 5 makes the landing gear enter a locking state, and the posture no longer changes.

[0026] Optionally, in the control method of the landing control system of the empty passive adaptive landing gear as described above, the way of turning on the adaptive control mechanism in step 1 is:

[0027] S11. After receiving the landing instruction, the controller 1 connects the electromagnetic valve 2 and the servo valve 4, so that the hydraulic source 10 is connected through the control oil circuit of the electromagnetic valve 2 to the reversing valve 3;

[0028] S12. The reversing valve 3 is connected, so that the oil circuit of the reversing valve 3 is connected through the servo valve 4 to the hydraulic lock 5;

[0029] S13, the hydraulic lock 5 is opened, the unlocking mechanism 6 is opened under the pressure of the hydraulic source 10, so that the piston rod of the retraction actuator 9 is freely stretched or compressed, and the landing gear enters the adaptive state.

[0030] Optionally, in the control method of the landing control system of the empty passive adaptive landing gear as described above, in step 4, based on the judgment of the extension stroke of all retraction actuators 9 and the landing load, the controller 1 immediately cuts off the output of the electromagnetic valve 2 and the servo valve 4 in the following way:

[0031] The controller 1 obtains the extension amount of all landing gear retraction actuators 9 through the displacement sensor 7; when the extension stroke of the retraction actuator 9 exceeds the threshold value 1, and the maximum value of the difference between the actuator extension strokes is less than the threshold value 2, it is determined that all landing gear attitudes are consistent;

[0032] The controller 1 obtains the load feedback of all landing gear force sensors 8, and the maximum value of the difference between the loads of all force sensors 8 is less than the threshold value 3, then the controller 1 cuts off the output of the electromagnetic valve 2 and the servo valve 4.

[0033] The beneficial effects of the present application are:

[0034] The embodiment of the present application provides a landing control system and control method of an empty passive adaptive landing gear, through the design of control lines, control oil circuits and servo oil circuits in the adaptive control mechanism configured for each landing gear, the adaptive landing gear has landing balance control function and arbitrary position attitude locking ability, can keep the aircraft attitude stable on a certain range of unstable and shaking platform, so as to realize the landing of the helicopter on the unstable and shaking platform, and the landing gear attitude does not need to be pre-adjusted before landing, and the landing process is more direct and fast. The technical scheme provided by the embodiment of the present application has the following key technical points:

[0035] 1) The present application provides a landing control method of an empty passive adaptive landing gear, the key point of which is that the landing gear attitude rising process is realized by the contact pushing of the ship surface and does not bear the load, and the landing gear attitude descending process uses the force sensor to judge the landing state and assists the hydraulic assistance, so that the landing gear has the ability to follow the unstable and shaking platform.

[0036] 2) The landing gear attitude adjustment is passive, without additional measurement equipment to measure and analyze the ship surface shaking frequency to calculate the landing gear position, the control system is changed from the previous measurement sensor active control optimization to passive control of the retraction actuator, reduces the attitude adjustment delay, and improves the accuracy of attitude adjustment.

[0037] 3) By controlling the working state of various hydraulic elements (solenoid valve, servo valve, hydraulic lock, unlocking mechanism) in the hydraulic circuit, the hydraulic flow direction and flow of the landing gear actuator are controlled, and the rapid locking of the landing gear posture is realized.

[0038] 4) The adaptive landing gear landing control method has an automatic capture function in the static period of the shaking deck. When all the landing gears complete the touch with the ship, whether the postures of the landing gears are consistent is judged according to the maximum difference of the strokes of all the landing gear extension and retraction actuators, and after the set threshold is met, a locking instruction is automatically sent to the controller to complete the posture locking. BRIEF DESCRIPTION OF DRAWINGS

[0039] The accompanying drawings are used to provide a further understanding of the technical solutions of the present application, and constitute a part of the specification, and are used together with the embodiments of the present application to explain the technical solutions of the present application, and do not constitute a limitation on the technical solutions of the present application.

[0040] Figure 1 It is a system architecture schematic diagram of the landing control system of the empty load passive adaptive landing gear of the present application.

[0041] Figure 2 It is a schematic diagram of the landing control system of the empty load passive adaptive landing gear provided by the embodiment of the present application applied to a helicopter.

[0042] Figure 3 It is a structural relationship schematic diagram of the slider lock, unlocking mechanism and extension and retraction actuator in the embodiment of the present application.

[0043] Figure 4 It is a flow chart of the implementation process of the control method of the landing control system of the empty load passive adaptive landing gear provided by the embodiment of the present application. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0045] As described above in the background, the existing control mode of the helicopter landing has the disadvantage that the active posture adjustment of the adaptive landing is performed through the measurement of multiple sensors, the frequency of the deck shaking is high, the static period is short, and the system delay exists in the process from the data measurement, analysis and processing to the sending of the landing gear posture instruction and the completion of the mechanism execution, so that the static period is easily missed. In addition, the sea environment is harsh, the more types of sensors required, the greater the difficulty of the hardware reliability requirement.

[0046] To address the aforementioned problems, embodiments of the present invention provide a shipboard landing control system and control method for an unloaded passive adaptive landing gear.

[0047] The present invention provides the following specific embodiments, which can be combined with each other. For the same or similar concepts or processes, they may not be described again in some embodiments.

[0048] Figure 1 This is a schematic diagram of the system architecture of the ship landing control system for an unloaded passive adaptive landing gear provided in an embodiment of the present invention. The ship landing control system for an unloaded passive adaptive landing gear provided in an embodiment of the present invention comprises: a controller 1 and a hydraulic source 10, and an adaptive control mechanism respectively configured on each landing gear.

[0049] like Figure 1 As shown, each adaptive control mechanism in this invention includes: a solenoid valve 2, a directional valve 3, a servo valve 4, a hydraulic lock 5, an unlocking mechanism 6, a retraction actuator 9, and a sensor. Figure 1 Only one adaptive control mechanism is shown in the diagram.

[0050] like Figure 1 As shown, in this embodiment of the invention, the controller 1 is electrically connected to the solenoid valve 2 and the servo valve 4 respectively. The hydraulic source 10, the solenoid valve 2 and the directional valve 3 are connected in sequence to form a control oil circuit. The directional valve 3 and the servo valve 4 are connected through a high-pressure oil circuit, and the servo valve 4 and the hydraulic lock 5 are connected through a servo oil circuit. The hydraulic source 10 is connected to the solenoid valve 2, the directional valve 3 and the servo valve 4 respectively. The unlocking mechanism 6 is installed in the cavity of the retraction actuator 9.

[0051] Each adaptive control mechanism can be controlled by the controller 1 to open the control oil circuit in the adaptive control mechanism and connect the servo oil circuit, so that the unlocking mechanism 6 opens under the pressure of the hydraulic source 10, allowing the piston rod of the retraction actuator 9 to be freely stretched or compressed, thereby enabling the landing gear system to enter the adaptive state.

[0052] It should be noted that the helicopters waiting to land on the ship are equipped with multiple landing gears, each with an adaptive control mechanism, such as... Figure 2 The diagram shown illustrates the application of the shipboard landing control system for the unloaded passive adaptive landing gear provided in this embodiment of the invention on a helicopter. All adaptive control mechanisms can share the controller 1 and the hydraulic power source 10.

[0053] In one implementation of this invention, each adaptive control mechanism further includes: a slider lock 11 and a spring 12; together with the unlocking mechanism 6, they form a locking and unlocking mechanism for the retractable actuator 9. Figure 3 The diagram shown illustrates the structural relationship between the slider lock, the unlocking mechanism, and the retraction actuator in an embodiment of the present invention.

[0054] In the implementation, the extension nozzle and the retraction nozzle are arranged outside the main structure of the retraction actuator 9, the extension nozzle is connected with the oil inlet pipeline of the hydraulic lock 5, and the retraction nozzle is connected with the oil return pipeline of the hydraulic lock 5.

[0055] The slider lock 11 is arranged between the main structure of the retraction actuator 9 and the piston rod, the unlocking mechanism 6 is arranged inside one end of the piston rod of the retraction actuator 9 in the rodless cavity, and the spring 12 is arranged between the unlocking mechanism and the piston rod; the unlocking mechanism 6 and the piston rod installation cavity are provided with a clamping groove for cooperating with the slider lock 11 to be locked.

[0056] Based on the structure and assembly relationship of the slider lock, the unlocking mechanism and the retraction actuator, in the embodiment of the present application, the locking mode of the piston rod in the retraction actuator 9 during the extension process is as follows:

[0057] When the hydraulic oil enters the extension nozzle through the oil path of the hydraulic lock 5, the spring 12 is pushed to move the unlocking mechanism 6 until the slider lock 11 is embedded into the clamping groove of the unlocking mechanism 6, and the piston rod cannot be elongated any more through the limitation of the slider lock 11.

[0058] The locking mode of the piston rod in the retraction actuator 9 during the retraction process is as follows:

[0059] During the retraction process of the piston rod, after the hydraulic oil enters the retraction nozzle through the oil path of the hydraulic lock 5, the slider lock 11 and the piston rod are pushed to move to one side of the rodless cavity, and the slider lock 11 returns to the original position under the elastic force of the spring 12 to be locked.

[0060] In the specific implementation of the embodiment of the present application, the sensor includes at least one of a displacement sensor 7 and a force sensor 8;

[0061] The displacement sensor 7 is installed on the piston rod of the retraction actuator 9, and the force sensor 8 is installed on the ground contact end of the landing gear.

[0062] Based on the above-mentioned embodiment of the present application, the embodiment of the present application further provides a control method of the landing control system of the empty passive adaptive landing gear, and the passive adaptive landing control method of the landing gear mechanism is performed by using the landing control system of the empty passive adaptive landing gear provided by any one of the above-mentioned embodiments, as shown in the figure. Figure 4 The embodiment process flowchart of the control method of the landing control system of the empty passive adaptive landing gear provided by the embodiment of the present application is shown in the figure. The passive adaptive landing control method includes the following steps:

[0063] Step 1: during the landing descent of the aircraft body, the adaptive control mechanism on each landing gear is started, so that the piston rod of the retraction actuator 9 is freely stretched, and the landing gear enters the adaptive state.

[0064] Step 2, the landing gear that has touched the ship still descends with the body and is adjusted passively, and the extension amount of the retraction actuator 9 is controlled by the controller 1;

[0065] Step 3, when the ship surface shakes and the landing gear that has touched the ship is separated from the state of touching the ship, the controller 1 connects the servo valve 4 to switch the oil circuit, and the retraction actuator 9 enters the retracted state, so that the landing gear position is lowered, thereby realizing the ship surface shaking following capability;

[0066] Step 4, after the last landing gear touches the ground, the controller 1 controls the output of the electromagnetic valve 2 and the servo valve 4 based on the judgment of the extension stroke of all retraction actuators 9 and the touch load, the flow locking in the hydraulic lock 5 makes the landing gear enter the locked state, and the attitude no longer changes.

[0067] In an implementation manner of the embodiment of the application, the manner of starting the adaptive control mechanism in step 1 is as follows:

[0068] S11, after the controller 1 receives the landing instruction, the electromagnetic valve 2 and the servo valve 4 are connected, so that the hydraulic source 10 is connected to the control oil circuit of the reversing valve 3 through the electromagnetic valve 2;

[0069] S12, the reversing valve 3 is connected, so that the oil circuit of the reversing valve 3 to the hydraulic lock 5 through the servo valve 4 is connected;

[0070] S13, the hydraulic lock 5 is opened, the unlocking mechanism 6 is opened under the pressure of the hydraulic source 10, so that the piston rod of the retraction actuator 9 is freely stretched or compressed, and the landing gear enters the adaptive state.

[0071] In an implementation manner of the embodiment of the application, in step 4, based on the judgment of the extension stroke of all retraction actuators 9 and the touch load, the manner that the controller 1 immediately cuts off the output of the electromagnetic valve 2 and the servo valve 4 is as follows:

[0072] The controller 1 obtains the extension amount of all landing gear retraction actuators 9 through the displacement sensor 7; when the extension stroke of the retraction actuator 9 exceeds the threshold 1, and the maximum value of the difference between the extension strokes of the actuators is less than the threshold 2, it is determined that the attitudes of all landing gears are consistent;

[0073] The controller 1 obtains the load fed back by all landing gear force sensors 8, and the maximum value of the difference between the loads of all force sensors 8 is less than the threshold 3, so that the controller 1 cuts off the output of the electromagnetic valve 2 and the servo valve 4.

[0074] The ship landing control system and method for an unloaded passive adaptive landing gear provided in this invention, through the design of control circuits, control oil circuits, and servo oil circuits in the adaptive control mechanisms configured in each landing gear, enables the adaptive landing gear to possess ship landing balance control functions and the ability to lock attitude at any position. This allows the helicopter to maintain a stable aircraft attitude on a swaying ship deck platform within a certain range, thereby enabling helicopter landings on unstable, swaying platforms. No pre-adjustment of the landing gear attitude is required before landing, making the landing process more direct and faster. The technical solution provided in this invention has the following key technical points:

[0075] 1) This invention proposes an unloaded passive adaptive landing gear landing control method. Its key point is that by combining hydraulic control with sensor measurement, the landing gear attitude rise process is achieved by contacting the ship deck and does not bear load. During the landing gear attitude descent process, the force sensor is used to determine the contact state with the ship and assists with hydraulic power, so that the landing gear has the ability to follow the unstable swaying platform.

[0076] 2) The landing gear attitude adjustment is passive, eliminating the need for additional measuring equipment to measure and analyze the ship deck sway frequency before calculating the landing gear position and attitude. The control system has been optimized from the previous active control by measurement sensors to passive control by the retraction and extension actuators, reducing attitude adjustment delay and improving the accuracy of attitude adjustment.

[0077] 3) By controlling the working status of various hydraulic components (solenoid valves, servo valves, hydraulic locks, and unlocking mechanisms) in the hydraulic circuit, the hydraulic flow direction and flow rate of the landing gear actuator are controlled to achieve rapid locking of the landing gear attitude.

[0078] 4) The adaptive landing gear landing control method has an automatic capture function for the rest period of the ship's sway deck. After all landing gears have completed the touch-down, the maximum difference in the stroke of all landing gear retraction actuators is used to determine whether the attitude of each landing gear is consistent. After the set threshold is met, a locking command is automatically sent to the controller to complete the attitude locking.

[0079] The following is a schematic description of the implementation of the ship landing control system and control method for the unloaded passive adaptive landing gear provided by the present invention through a specific embodiment.

[0080] Example

[0081] The carrier landing control system for an unloaded passive adaptive landing gear provided in this embodiment comprises the following components: a controller 1, a solenoid valve 2, a reversing valve 3, a servo valve 4, a hydraulic lock 5, an unlocking mechanism 6, a displacement sensor 7, a force sensor 8, a retraction actuator 9, and a hydraulic source 10; wherein, the displacement sensor 7 is mounted on the piston rod of the retraction actuator 9, and the force sensor 8 is mounted on the ground contact end of the landing gear.

[0082] likeFigure 1 The oil circuit of the landing control system of the passive self-adaptive landing gear is shown in the figure, and the control principle is as follows:

[0083] After the helicopter is in the hovering position, the controller 1 receives the landing instruction and turns on the electromagnetic valve 2 and the servo valve 4. At this time, the control oil circuit is opened, so that the hydraulic source 10 is connected to the control oil circuit of the reversing valve 3 through the electromagnetic valve 2, the reversing valve 3 is connected, so that the oil circuit of the reversing valve 3 is connected to the hydraulic lock 5 through the servo valve 4, the hydraulic lock 5 is opened, the unlocking mechanism 6 is opened under the pressure of the hydraulic source 10, so that the piston rod of the retractable actuator 9 can be freely stretched or compressed, and the landing gear system enters the adaptive state, such as Figure 3 The posture of the adaptive state is shown in the figure.

[0084] It should be noted that the piston rod of the retractable actuator 9 in this embodiment will not be locked in the limit compression position and the limit extension position.

[0085] As shown in Figure 3 The retractable actuator 9 main body structure is provided with an extension nozzle and a retraction nozzle outside, and the extension nozzle and the retraction nozzle are connected with the oil inlet pipeline and the oil return pipeline of the hydraulic lock 5 respectively. The retractable actuator 9 main body structure and the piston rod are provided with a sliding block lock 11, the unlocking mechanism 6 is in the rodless cavity, which is installed inside the piston rod at one end of the rodless cavity, and the unlocking mechanism and the piston rod are provided with a spring 12.

[0086] When the hydraulic oil enters the extension nozzle through the oil circuit of the hydraulic lock 5, the unlocking mechanism 6 is pushed to move against the spring force, when the end surface of the unlocking mechanism 6 contacts with the end surface of the rodless cavity, the unlocking mechanism 6 and the piston rod are pushed together by the oil pressure and move to the side of the rod cavity, until the sliding block lock 11 is embedded into the locking slot of the unlocking mechanism 6, so that the piston rod cannot be stretched any more through the limitation of the sliding block lock 11. In the process of retracting the piston rod, the hydraulic oil enters the retraction nozzle through the oil circuit of the hydraulic lock 5, pushes the sliding block lock 11 and the piston rod to move to the side of the rodless cavity, and the sliding block lock 11 returns to the original position under the action of the spring 12.

[0087] The landing implementation process of the passive self-adaptive landing gear is shown in the figure. Figure 4

[0088] During the process of the aircraft landing and descending, when one landing gear first touches the ship, the landing gear still descends with the aircraft to passively adjust the posture. It should be noted that the landing instruction has been received before touching the ship, and the adaptive control mechanism starts to work. After landing, the displacement sensor 7 and the force sensor 8 feed back signals to the controller 1.

[0089] ​Based on the landing gear structure, the landing gear does not bear load in the passive attitude adjustment process, the attitude adjustment process is realized by the self-adaptive structure of the landing gear, and the controller 1 controls the extension amount of the retraction actuator 9. The controller 1 obtains the extension amount of the retraction actuator 9 by collecting the data of the displacement sensor 7 in real time, and the force sensor 8 obtains the landing load of the landing gear.

[0090] When the ship surface shakes to the other side, the landing gear is out of the landing state, and the force sensor 8 has no load measurement value; at this time, the controller 1 connects the servo valve 4 to switch the oil circuit, the retraction actuator 9 enters the contraction state, and the landing gear position and posture are lowered, thereby realizing the ship surface shaking following capability.

[0091] When the last landing gear touches the ground, the controller 1 obtains the extension amount of all the retraction actuators 9 of the landing gear through the displacement sensor 7. The stroke of all the retraction actuators 9 exceeds the threshold 1 (for example, 10 mm), and the maximum value of the difference between the strokes of the actuators is less than the threshold 2 (5 mm), so it is considered that the attitudes of all the landing gears are consistent; the controller 1 obtains the load feedback of the force sensor 8 on all the landing gears, the maximum value of the difference between the loads of all the force sensors 8 is less than the threshold 3 (for example, several hundred Newton, 300 N), the controller 1 immediately cuts off the output of the electromagnetic valve 2 and the servo valve 4, the flow locking in the hydraulic lock 5 makes the landing gear enter the locking state, and the attitude no longer changes, and the subsequent landing process is consistent with the conventional landing gear.

[0092] Although the embodiments of the present application are disclosed as above, the content is only the embodiment adopted for the purpose of understanding the present application, and is not used to limit the present application. Any person skilled in the art of the present application can make any modification and change in the implementation form and details without departing from the spirit and scope of the present application, but the patent protection scope of the present application should be subject to the scope defined by the attached claims.

Claims

1. A system for controlling the landing of an unpowered, passive, self- adaptive landing gear, characterized in that, The system comprises a controller (1) and a hydraulic source (10), and one set of adaptive control mechanism arranged on each landing gear respectively; Each set of adaptive control mechanism comprises an electromagnetic valve (2), a reversing valve (3), a servo valve (4), a hydraulic lock (5), an unlocking mechanism (6), a retractable actuator (9) and a sensor; The controller (1) is electrically connected with the electromagnetic valve (2) and the servo valve (4) respectively, the hydraulic source (10), the electromagnetic valve (2) and the reversing valve (3) are sequentially communicated to form a control oil circuit, the reversing valve (3) and the servo valve (4) are communicated through a high-pressure oil circuit, the servo valve (4) and the hydraulic lock (5) are communicated through a servo oil circuit, and the hydraulic source (10) is connected to the electromagnetic valve (2), the reversing valve (3) and the servo valve (4) respectively; the unlocking mechanism (6) is arranged in the cavity of the retractable actuator (9); Each set of adaptive control mechanism is used for controlling opening of the control oil circuit in the adaptive control mechanism and connection of the servo oil circuit according to the instruction of the controller (1), so that the unlocking mechanism (6) is opened under the pressure of the hydraulic source (10), the piston rod of the retractable actuator (9) can be freely stretched or compressed, and the landing gear system enters an adaptive state; Each adaptive control mechanism further comprises a slider lock (11) and a spring (12); The retractable actuator (9) is provided with an extension nozzle and a retraction nozzle outside the main structure, the extension nozzle is connected with an oil inlet pipeline of the hydraulic lock (5), and the retraction nozzle is connected with an oil return pipeline of the hydraulic lock (5); The slider lock (11) is arranged between the main structure of the retractable actuator (9) and the piston rod, the unlocking mechanism (6) is arranged inside one end of a rodless cavity of the piston rod, and the spring (12) is arranged between the unlocking mechanism and the piston rod; a clamping groove is arranged between the unlocking mechanism (6) and a piston rod mounting cavity, and is used for cooperation locking with the slider lock (11). In the extension process of the piston rod in the retractable actuator (9), the locking mode is as follows:

2. The control system for the unpowered passive self- adaptive landing gear of claim 1, wherein, After the hydraulic oil enters the extension nozzle through the oil circuit of the hydraulic lock (5), the spring (12) is pushed to move the unlocking mechanism (6) until the slider lock (11) is embedded into the clamping groove of the unlocking mechanism (6), and the piston rod cannot be elongated any more through the limitation of the slider lock (11). In the contraction process of the piston rod in the retractable actuator (9), the locking mode is as follows:

3. The control system for the unpowered passive self- adaptive landing gear of claim 2, wherein, In the contraction process of the piston rod, after the hydraulic oil enters the retraction nozzle through the oil circuit of the hydraulic lock (5), the slider lock (11) and the piston rod are pushed to move to one side of the rodless cavity, and the slider lock (11) returns to the original position under the elastic force of the spring (12) to lock. The sensor comprises at least one of a displacement sensor (7) and a force sensor (8); 4. The control system for the unpowered passive adaptive landing gear of any one of claims 1 to 3, wherein, The displacement sensor (7) is arranged on the piston rod of the retractable actuator (9), and the force sensor (8) is arranged at a ground contact end of the landing gear.

5. The system according to any one of claims 1-3, wherein ​ The landing helicopter is provided with multiple landing gears, each of which is provided with a set of adaptive control mechanisms, and all the adaptive control mechanisms share a controller (1) and a hydraulic source (10).

6. A control method of a control system of an unpowered passive adaptive landing gear for a carrier landing, characterized in that, The passive adaptive landing control method for the landing gear mechanism is performed by using the landing control system of the idle passive adaptive landing gear according to any one of claims 1-5, and the passive adaptive landing control method comprises the following steps: Step 1: during the landing descent of the aircraft body, the adaptive control mechanism of each landing gear is started, so that the piston rod of the retraction actuator (9) is freely stretched, and the landing gear enters an adaptive state; Step 2: the landing gear that has touched the ship is still passively adjusted in posture during the descent of the aircraft body, and the extension amount of the retraction actuator (9) is controlled through the controller (1); Step 3: when the ship surface shakes and the landing gear that has touched the ship is out of the touch state, the controller (1) connects the servo valve (4) to switch the oil circuit, the retraction actuator (9) enters the contraction state, so that the landing gear posture is lowered, thereby realizing the ship surface shaking following capability; Step 4: after the last landing gear touches the ground, the controller (1) judges the extension stroke and the touch load of all retraction actuators (9), and immediately cuts off the output of the electromagnetic valve (2) and the servo valve (4), and the flow locking in the hydraulic lock (5) makes the landing gear enter the locking state, and the posture no longer changes.

7. The control method of the control system of the unpowered passive adaptive landing gear for aircraft according to claim 6, characterized in that, The starting mode of the adaptive control mechanism in step 1 is as follows: S11: after the controller (1) receives the landing instruction, the electromagnetic valve (2) and the servo valve (4) are connected, so that the hydraulic source (10) is connected through the control oil circuit of the electromagnetic valve (2) to the reversing valve (3); S12: the reversing valve (3) is connected, so that the oil circuit of the reversing valve (3) is connected through the servo valve (4) to the hydraulic lock (5); S13: the hydraulic lock (5) is opened, the unlocking mechanism (6) is opened under the pressure of the hydraulic source (10), so that the piston rod of the retraction actuator (9) is freely stretched or compressed, and the landing gear enters the adaptive state.

8. The control method of the control system of the unpowered passive adaptive landing gear for aircraft according to claim 6, characterized in that, In step 4, based on the judgment of the extension stroke and the touch load of all retraction actuators (9), the controller (1) immediately cuts off the output of the electromagnetic valve (2) and the servo valve (4) in the following manner: The controller (1) obtains the extension amount of all landing gear retraction actuators (9) through the displacement sensor (7); when the extension stroke of the retraction actuator (9) exceeds the threshold value 1, and the maximum value of the difference between the extension strokes of the actuators is less than the threshold value 2, it is determined that the postures of all landing gears are consistent; The controller (1) obtains the load feedback of all landing gear force sensors (8), and when the maximum value of the difference between the loads of all force sensors (8) is less than the threshold value 3, the controller (1) cuts off the output of the electromagnetic valve (2) and the servo valve (4).

Images