Detection unmanned aerial vehicle multi-wheel-leg hydraulic servo self-adaptive system and control method thereof

Abstract

The invention relates to the field of transportation of detection equipment, and provides a detection unmanned aerial vehicle multi-wheel-leg hydraulic servo self-adaptive system and a control method thereof, and the detection unmanned aerial vehicle multi-wheel-leg hydraulic servo self-adaptive system comprises a driving device, a lifting device and a folding and unfolding device. The lifting device and the retracting device are connected in parallel and do not influence each other, and the lifting device adjusts the height of the wheel legs in a self-adaptive mode according to changes of the external environment to maintain stable sliding; and the folding and unfolding device completes folding and unfolding of the wheel legs of the unmanned aerial vehicle according to a given folding and unfolding signal. The loading space in the unmanned aerial vehicle is expanded in a hydraulic driving mode; the self-adaptive height of the wheel legs of the unmanned aerial vehicle is adjusted according to the change of the external environment, stable sliding is kept, and the stability of the take-off and landing process is guaranteed; the height adjustment of the wheel legs of the unmanned aerial vehicle provides a more stable working channel for the probe vehicle carried in the unmanned aerial vehicle.

Description

Technical Field

[0001] The present invention belongs to the field of transportation of detection equipment, and in particular relates to a multi-wheel-leg hydraulic servo adaptive system of a detection unmanned aerial vehicle and a control method thereof. Background Art

[0002] UAV technology has excellent maneuverability and flexibility. UAVs can not only adapt to complex aerial environments and perform efficient patrol missions, but also reach areas that are difficult for humans to reach or enter and perform various key tasks. In the field of environmental exploration, UAVs can transport heavy equipment such as detection vehicles to designated work sites to conduct detailed geological, environmental or meteorological exploration, greatly expanding the scope and depth of exploration. In the process of environmental exploration, to achieve the required tasks, UAVs are required to have not only a strong carrying capacity to ensure the safe transportation of detection equipment and other loads, but also precise take-off and landing functions so that the detection vehicle can smoothly get on and off the UAV and successfully complete the exploration mission. The lifting and landing action of the UAV is the key link in its mission execution, and the lifting and landing process of the UAV mainly depends on the design and performance of its wheel-leg mechanism. The wheel-leg mechanism must not only be able to support the weight and load of the UAV, but also be able to achieve smooth lifting and landing movements in various environmental terrains. This requires the wheel-leg control system of the UAV to have a high degree of accuracy and adaptability, and to be able to make quick and accurate adjustments according to different environmental conditions to ensure the stability and safety of the UAV during take-off, landing and hovering.

[0003] For existing conventional drones, the design of the drone is often based on a bracket fixed to the fuselage, which lacks flexibility and adjustment capabilities. This means that the bracket cannot adjust its lifting position according to the ups and downs or changes in the terrain, making it difficult to achieve smooth takeoff and landing on rugged roads. At the same time, it is also impossible to ensure the smooth transportation of the exploration vehicle, and it is not conducive to the exploration vehicle getting on and off the drone. In addition, when the drone carries heavier objects, the bracket may be damaged due to excessive pressure, showing its insufficient carrying capacity. These problems limit the application of drones in more complex and demanding environments. Summary of the invention

[0004] In view of the problems existing in the prior art of how to improve the adaptability and stability of the lifting and landing of UAVs in different terrain environments, as well as the ability to carry exploration equipment and ensure the smooth entry and exit of exploration equipment, the present invention provides a multi-wheel leg hydraulic servo adaptive system for exploration UAVs and a control method thereof, which replaces conventional electric control with hydraulic control to keep the UAV stable during takeoff and landing in non-smooth paths. The present invention is achieved through the following technical solutions:

[0005] A multi-wheel and leg hydraulic servo adaptive system for a detection unmanned aerial vehicle, comprising a driving device, a lifting device and a retracting device, wherein the lifting device and the retracting device are connected in parallel to the driving device, the driving device comprising an oil tank, a plunger pump, a first fine filter, an accumulator, a safety stop valve and a second pressure gauge, the third port of the oil tank is connected to the fifth port of the plunger pump, the first port, the second port and the third port of the first fine filter are respectively connected to the first port of the plunger pump, the second pressure gauge and the accumulator; the lifting device comprises a first wheel leg hydraulically controlled lifting assembly, a second wheel leg hydraulically controlled lifting assembly, a third wheel leg hydraulically controlled lifting assembly, a fourth wheel leg hydraulically controlled lifting assembly, a fifth wheel leg hydraulically controlled lifting assembly, a sixth wheel leg hydraulically controlled lifting assembly and a seventh wheel leg hydraulically controlled lifting assembly, the first wheel leg hydraulically controlled lifting assembly A lifting and lowering assembly, which includes a two-way control wheel-leg lifting electro-hydraulic servo valve, a wheel-leg lifting hydraulic cylinder, a wheel-leg lifting displacement sensor assembly, and a wheel-leg lifting force sensor assembly. The first port and the second port of the two-way control wheel-leg lifting electro-hydraulic servo valve are respectively connected to the first end and the second end of the wheel-leg lifting hydraulic cylinder, and the first mounting end and the second mounting end of the piston rod of the wheel-leg lifting hydraulic cylinder are respectively connected to the first wheel-leg lifting displacement sensor and the first wheel-leg lifting force sensor; the retracting and extending device includes a wheel-leg retracting and extending hydraulic cylinder assembly, a wheel-leg retracting and extending synchronous valve, and a two-way control wheel-leg retracting and extending hydraulic reversing valve. The first port of the two-way control wheel-leg retracting and extending hydraulic reversing valve is connected to the input end of the wheel-leg retracting and extending hydraulic cylinder assembly through the wheel-leg retracting and extending synchronous valve, and the second port of the two-way control wheel-leg retracting and extending hydraulic reversing valve is connected to the output end of the wheel-leg retracting and extending hydraulic cylinder assembly.

[0006] Preferably, the wheel-leg retracting and extending hydraulic cylinder assembly comprises a first wheel-leg retracting and extending hydraulic cylinder assembly, a second wheel-leg retracting and extending hydraulic cylinder assembly, a third wheel-leg retracting and extending hydraulic cylinder assembly, a fourth wheel-leg retracting and extending hydraulic cylinder assembly, a fifth wheel-leg retracting and extending hydraulic cylinder assembly, a sixth wheel-leg retracting and extending hydraulic cylinder assembly and a seventh wheel-leg retracting and extending hydraulic cylinder assembly, and the first mounting end and the second mounting end of the piston rod of the first wheel-leg retracting and extending hydraulic cylinder assembly are respectively connected to the first wheel-leg retracting and extending displacement sensor and the first wheel-leg retracting and extending force sensor, and the first wheel-leg retracting and extending hydraulic cylinder assembly realizes the retraction and extension of the first wheel leg of the UAV through the movement of the piston.

[0007] Preferably, the first wheel leg retracting hydraulic cylinder assembly, the second wheel leg retracting hydraulic cylinder assembly, the third wheel leg retracting hydraulic cylinder assembly, the fourth wheel leg retracting hydraulic cylinder assembly, the fifth wheel leg retracting hydraulic cylinder assembly, the sixth wheel leg retracting hydraulic cylinder assembly and the seventh wheel leg retracting hydraulic cylinder assembly have the same structure and the same connection control method.

[0008] Preferably, the first wheel-leg hydraulically-controlled lifting assembly controls the lifting distance of the first wheel-leg through the movement of a piston rod, and the wheel-leg hydraulically-controlled lifting assemblies in the lifting device are connected in parallel with each other, and the wheel-leg hydraulically-controlled lifting assemblies can be controlled separately, and the structure and connection control method of each wheel-leg hydraulically-controlled lifting assembly are the same.

[0009] Preferably, the driving device further comprises a first cooler, a second cooler, a first pressure gauge, a relief valve, a thermometer, a heater, a hydraulic pressure gauge, a servo motor and a coarse filter, the first port, the second port, the fourth port, the fifth port, the sixth port, the seventh port, the eighth port and the ninth port of the oil tank are respectively connected to the first cooler, the first pressure gauge, the coarse filter, the relief valve, the thermometer, the heater, the second cooler and the hydraulic pressure gauge, the second port, the third port, the fourth port and the fifth port of the plunger pump are sequentially connected to the relief valve, the output end of the servo motor, the coarse filter and the third port of the oil tank, the second port, the third port, the fourth port and the fifth port of the first fine filter are respectively connected to the second pressure gauge, the accumulator, the lifting device and the retracting device. The accumulator, the safety stop valve and the second pressure gauge constitute a hydraulic pressure monitoring device.

[0010] A second aspect of the present invention provides a control method for the multi-wheeled leg hydraulic servo adaptive system of the aforementioned detection drone, which includes a drone take-off control step S1 and a drone landing control step S2;

[0011] The control step S1 of the drone takeoff process specifically includes the following sub-steps:

[0012] S11, adaptive lifting of wheel legs of UAV: ​​the wheel leg lifting force sensor and the wheel leg lifting displacement sensor corresponding to each wheel leg of the UAV receive the pressure change of the wheel leg by the external environment, and realize the adaptive lifting of all wheel legs of the UAV by changing the working position of the bidirectional control wheel leg lifting electro-hydraulic servo valve;

[0013] S12, UAV wheel leg recovery: the control center gives a wheel leg recovery signal, and realizes the recovery of all UAV wheel legs by changing the working direction of the hydraulic reversing valve for bidirectionally controlling wheel leg retraction;

[0014] The control step S2 of the drone landing process specifically includes the following sub-steps:

[0015] S21, the UAV wheel legs are released; the control center gives a wheel leg release signal, and all the UAV wheel legs are released by changing the working position of the hydraulic reversing valve for bidirectionally controlling the wheel leg retraction;

[0016] S22. Adaptive lifting of UAV wheel legs: The wheel leg lifting force sensor and the wheel leg lifting displacement sensor corresponding to each wheel leg of the UAV receive the pressure changes of the wheel legs from the external environment, and realize adaptive lifting of all UAV wheel legs by changing the working position of the bidirectionally controlled wheel leg lifting electro-hydraulic servo valve.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] 1. The UAV wheel-leg hydraulic servo adaptive lifting system of the present invention realizes adaptive adjustment of the UAV wheel legs according to the detection environment through a lifting device to bidirectionally control the wheel-leg lifting electro-hydraulic servo valve. The wheel-leg lifting displacement sensor and the wheel-leg lifting force sensor sense the road conditions, and analyze the vertical displacement change of the lifting hydraulic cylinder and the force on the wheel legs, and transmit the signal to the bidirectional control wheel-leg lifting electro-hydraulic servo valve. After receiving the signal, the electro-hydraulic servo valve will accurately adjust the valve opening size, thereby realizing fine adjustment of the fluid pressure and flow, thereby adjusting the lifting height of the wheel legs, so that the wheel legs can always adapt to the road conditions, which is more conducive to the take-off and landing of the UAV.

[0019] 2. The UAV wheel-leg hydraulic servo adaptive lifting system of the present invention ensures the stability of the UAV's take-off and landing through an adaptive adjustment mechanism, and provides a stable transportation platform for the exploration vehicle carried inside the UAV. In addition, the UAV wheel-leg hydraulic servo adaptive lifting system of the present invention can freely adjust the lifting height of the wheel legs according to the operator's command information to achieve the most suitable fuselage inclination, making it convenient for the exploration vehicle loaded inside the UAV to smoothly enter and exit the UAV.

[0020] 3. The UAV wheel-leg hydraulic servo adaptive lifting system of the present invention changes the electric drive mode of traditional detection UAVs. By adopting hydraulic drive, the detection UAV can achieve greater carrying capacity and stability with a smaller size and weight. In addition, the hydraulic drive mode enables the detection UAV to have a larger loading space inside, which can carry multiple exploration vehicles or other exploration equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is the hydraulic diagram of the hydraulic servo adaptive system of the multi-wheeled legs of the UAV of the present invention;

[0022] Figure 2 This is a diagram of the hydraulic control lifting assembly of the first wheel leg in the multi-wheel leg hydraulic servo adaptive system of the UAV of the present invention;

[0023] Figure 3 It is a left-right position diagram of the hydraulic reversing valve for bidirectionally controlling wheel-leg retraction in the multi-wheel-leg hydraulic servo adaptive system of the UAV of the present invention;

[0024] Figure 4It is a control flow chart of the UAV multi-wheel leg hydraulic servo adaptive system of the present invention during the UAV take-off process;

[0025] Figure 5 This is a main control flow chart of the UAV multi-wheel leg hydraulic servo adaptive system of the present invention during the UAV landing process;

[0026] Figure 6 The present invention is a flowchart of the hydraulic servo adaptive system for the multi-wheeled legs of the unmanned aerial vehicle.

[0027] Main reference numerals:

[0028] Oil tank 1, thermometer 2, heater 3, liquid level gauge 4, first cooler 51, second cooler 52, first pressure gauge 61, second pressure gauge 62, accumulator 7, safety stop valve 8, first fine filter 91, second fine filter 92, servo motor 10, plunger pump 11, overflow valve 12, coarse filter 13, drive device 14, lifting device 15, first wheel leg hydraulic control lifting assembly 151, second wheel leg hydraulic control lifting assembly 152, third wheel leg hydraulic control lifting assembly 153, fourth wheel leg hydraulic control lifting assembly 154, fifth wheel leg hydraulic control lifting assembly 155, sixth wheel leg hydraulic control lifting assembly 156, seventh wheel leg hydraulic control lifting assembly 157, first two-way control wheel leg lifting electro-hydraulic servo valve 1511, The first wheel leg lifting hydraulic cylinder 1512, the first wheel leg lifting displacement sensor 1513, the first wheel leg lifting force sensor 1514, the retracting device 16, the wheel leg retracting hydraulic cylinder assembly 161, the wheel leg retracting synchronization valve 162, the two-way control wheel leg retraction hydraulic reversing valve 163, the first wheel leg retracting hydraulic cylinder assembly 1611, the second wheel leg retracting hydraulic cylinder assembly 1612, the third wheel leg retracting hydraulic cylinder assembly 1613, the fourth wheel leg retracting hydraulic cylinder assembly 1614, the fifth wheel leg retracting hydraulic cylinder assembly 1615, the sixth wheel leg retracting hydraulic cylinder assembly 1616, the seventh wheel leg retracting hydraulic cylinder assembly 1617, the first wheel leg retracting hydraulic cylinder 16111, the first wheel leg retracting displacement sensor 16112, the first wheel leg retracting force sensor 16113. DETAILED DESCRIPTION

[0029] In order to fully describe the technical content, objectives and effects of the present invention, the following will be described in detail with reference to the accompanying drawings.

[0030] The present invention provides a multi-wheel leg hydraulic servo adaptive system for detecting unmanned aerial vehicles, such as Figure 1-Figure 3 As shown, it includes a driving device 14, a lifting device 15 and a retracting device 16. The lifting device 15 and the retracting device 16 are connected to the driving device 14 in parallel.

[0031] The driving device is the power source of the hydraulic servo adaptive system of the multi-wheeled legs of the UAV of the present invention. Figure 1 The figure includes an oil tank 1, a thermometer 2, a heater 3, a liquid level gauge 4, a cooler assembly, a pressure gauge assembly, an accumulator 7, a safety stop valve 8, a first fine filter 91, a servo motor 10, a plunger pump 11, an overflow valve 12 and a coarse filter 13, wherein the first port and the eighth port of the oil tank 1 are connected to the first cooler 51 and the second cooler 52 respectively, the first cooler 51 is connected to the retractable device 16 through an oil return pipeline, and the second cooler 52 is connected to the lifting device 15 through an oil return pipeline, and the first cooler 51 and the second cooler 52 cool the low-pressure hydraulic oil in the retractable device 16 and the lifting device 15 and return it to the oil tank 1 to form a closed loop. The second port of the oil tank 1 is connected to the first pressure gauge 61, and the first pressure gauge 61, the accumulator 7 and the safety stop valve 8 constitute a hydraulic pressure monitoring device. The third port, the fourth port and the fifth port of the oil tank 1 are respectively connected to the plunger pump 11, the coarse filter 13 and the relief valve 12. The first port, the second port, the third port and the fourth port of the plunger pump 11 are connected to the first fine filter 91, the relief valve 12, the output end of the servo motor 10 and the coarse filter 13 in sequence. The first output port, the second output port, the third output port and the fourth output port of the first fine filter 91 are respectively connected to the second pressure gauge 62, the accumulator 7, the lifting device and the retracting device. The sixth port, the seventh port and the ninth port of the oil tank 1 are respectively connected to the thermometer 2, the heater 3 and the liquid level gauge 4 to monitor and adjust the temperature and pressure in the system in real time. The first port, the second port, the third port, the fourth port and the fifth port of the first fine filter 91 are respectively connected to the first port of the plunger pump 11, the second pressure gauge 62, the accumulator 7, the lifting device 15 and the retracting device 16. In addition, the lifting device 15 is connected to the fourth port of the first fine filter 91 through the second fine filter 92. The lifting device 15 has a high control accuracy and is easily affected by impurities, so it needs to be filtered again by the second fine filter 92.

[0032] Specifically, during the operation of the UAV multi-wheel leg hydraulic servo adaptive system, the hydraulic oil in the oil tank 1 first enters the high-pressure oil circuit through the plunger pump 11 and then passes through the coarse filter 13 and the first fine filter 91 in turn. After filtering out the particles and impurities in the hydraulic oil, the hydraulic pressure of the hydraulic oil is adjusted through the relief valve 12. When the hydraulic oil pressure in the system is high, the relief valve 12 controls the flow of the hydraulic oil to reduce the pressure of the hydraulic oil in the system. On the contrary, when the hydraulic oil pressure in the system is low, the relief valve 12 will not hinder the flow of the hydraulic oil. The hydraulic oil adjusted by the relief valve 12 enters the lifting device and the retracting device through the high-pressure oil pipeline to drive the operation of each actuator component, and finally returns the hydraulic oil in the system to the oil tank 1 through the low-pressure oil circuit, and flows into the oil tank 1 after the oil temperature is reduced by the cooler 5. The thermometer 2, the second pressure gauge 62, and the level gauge 4 respectively monitor the oil temperature and pressure value in the high-pressure oil circuit and the level of the hydraulic oil in the oil tank 1 during the operation of the system. The heater 3 is responsible for heating the hydraulic oil in a low-temperature environment to prevent the hydraulic oil from being overcooled and affecting the normal operation of the hydraulic system; the accumulator 7 in the hydraulic pressure monitoring device stores hydraulic energy to balance the system pressure fluctuations; the safety shut-off valve 8 automatically cuts off the fluid flow in the event of system overpressure or emergency to protect the hydraulic system and equipment from damage.

[0033] The lifting device and the retracting device are the control systems of the main functions of the present invention, such as Figure 1 As shown, the lifting device 15 and the retracting device 16 are connected in parallel to each other, and are connected to the oil tank 1 through the low-pressure oil circuit with the first cooler 51 and the second cooler 52 respectively. The lifting device 15 includes a first wheel leg hydraulic control lifting assembly 151, a second wheel leg hydraulic control lifting assembly 152, a third wheel leg hydraulic control lifting assembly 153, a fourth wheel leg hydraulic control lifting assembly 154, a fifth wheel leg hydraulic control lifting assembly 155, a sixth wheel leg hydraulic control lifting assembly 156 and a seventh wheel leg hydraulic control lifting assembly 157, wherein Figure 2As shown, the components in the lifting device are connected in parallel with each other, and the lifting height of the wheel legs of the drone can be adjusted separately. The first wheel leg hydraulically controlled lifting component 151, the second wheel leg hydraulically controlled lifting component 152, the third wheel leg hydraulically controlled lifting component 153, the fourth wheel leg hydraulically controlled lifting component 154, the fifth wheel leg hydraulically controlled lifting component 155, the sixth wheel leg hydraulically controlled lifting component 156 and the seventh wheel leg hydraulically controlled lifting component 157 have the same structure. Specifically, the first wheel leg hydraulically controlled lifting component includes a first bidirectional control wheel leg lifting component. The electro-hydraulic servo valve 1511, the first wheel-leg lift hydraulic cylinder 1512, the first wheel-leg lift displacement sensor 1513 and the first wheel-leg lift force sensor 1514, the T port and the P port of the two-way control wheel-leg lift electro-hydraulic servo valve 1511 are respectively connected to the low-pressure oil circuit and the high-pressure oil circuit, the first port and the second port are connected to the first wheel-leg lift hydraulic cylinder 1512, the first displacement sensor 1513 and the first wheel-leg lift force sensor 1514 of the wheel-leg lift system are connected in parallel to the second end of the piston rod of the first wheel-leg lift hydraulic cylinder 1512.

[0034] Specifically, each wheel leg in the lifting device realizes the adaptive height change of the UAV wheel leg to different detection environments according to the specific signal obtained by the control end of the two-way control wheel leg lifting electro-hydraulic servo valve, thereby improving the safety of take-off and landing. Taking the first wheel leg hydraulic control lifting component 151 as an example, when the two-way control wheel leg lifting electro-hydraulic servo valve of the first wheel leg hydraulic control lifting component is in the initial position, the UAV wheel leg is at a normal height. When the external detection environment hinders the current height of the UAV wheel leg, the first displacement sensor 1513 and the first force sensor 1514 of the first wheel leg hydraulic control lifting component collect data on the current external detection environment and transmit it back to the control end of the first two-way control wheel leg lifting electro-hydraulic servo valve 1511, so that the first port of the first two-way control wheel leg lifting electro-hydraulic servo valve 1511 is connected to the P port, and the second port is connected to the T port. Since the first port is indirectly connected to the low-pressure oil circuit and the second port is indirectly connected to the high-pressure oil circuit, the change in oil pressure causes the first wheel leg lifting hydraulic cylinder 151 to 2, the piston moves upward, thereby realizing the adaptive rise of the wheel leg of the UAV to the external detection environment; on the contrary, when the current height of the wheel leg of the UAV is difficult to take off or land smoothly in this external detection environment, the first displacement sensor 1513 and the first force sensor 1514 of the first wheel leg hydraulic control lifting assembly collect data of the existing external detection environment and transmit it back to the control end of the first two-way control wheel leg lifting electro-hydraulic servo valve 1511, thereby realizing the first port of the first two-way control wheel leg lifting electro-hydraulic servo valve 1511 is connected to the T port, and the second port is connected to the P port. In this case, the first port is indirectly connected to the high-pressure oil circuit, and the second port is indirectly connected to the low-pressure oil circuit, causing the piston of the first wheel leg lifting hydraulic cylinder 1513 to move downward, thereby realizing the adaptive descent of the wheel leg of the UAV to the external detection environment.

[0035] The retracting device 16 includes a wheel leg retracting hydraulic cylinder assembly 161, a wheel leg retracting synchronous valve 162 and a two-way control wheel leg retracting hydraulic reversing valve 163. The two-way control wheel leg retracting hydraulic reversing valve 163 is connected to the wheel leg retracting hydraulic cylinder assembly 161 through the wheel leg retracting synchronous valve 162. The components of the wheel leg retracting hydraulic cylinder assembly 161 are connected in parallel. The wheel leg retracting hydraulic cylinder assembly 161 includes a first wheel leg retracting hydraulic cylinder assembly 1611, a second wheel leg retracting hydraulic cylinder assembly 1612, and a third wheel leg retracting hydraulic cylinder assembly 1613. The wheel-leg retracting and extending hydraulic cylinder assembly 1613, the fourth wheel-leg retracting and extending hydraulic cylinder assembly 1614, the fifth wheel-leg retracting and extending hydraulic cylinder assembly 1615, the sixth wheel-leg retracting and extending hydraulic cylinder assembly 1616 and the seventh wheel-leg retracting and extending hydraulic cylinder assembly 1617, the first wheel-leg retracting and extending hydraulic cylinder assembly realizes the retraction and extension of the first wheel legs of the UAV through the movement of the piston, and the first wheel-leg retracting and extending hydraulic cylinder assembly is composed of the first wheel-leg retracting and extending hydraulic cylinder 16111, the first wheel-leg displacement sensor 16112 and the first wheel-leg force sensor 16113.

[0036] like Figure 3 As shown, the first wheel leg retracting hydraulic cylinder assembly 1611, the second wheel leg retracting hydraulic cylinder assembly 1612, the third wheel leg retracting hydraulic cylinder assembly 1613, the fourth wheel leg retracting hydraulic cylinder assembly 1614, the fifth wheel leg retracting hydraulic cylinder assembly 1615, the sixth wheel leg retracting hydraulic cylinder assembly 1616 and the seventh wheel leg retracting hydraulic cylinder assembly 1617 are respectively connected to the first port, the second port, the third port, the fourth port, the fifth port, the sixth port and the seventh port of the output end of the wheel leg retracting synchronization valve 162, and the components of the wheel leg retracting hydraulic cylinder assembly 161 are connected in parallel with each other and connected to the second port of the two-way control wheel leg retracting hydraulic reversing valve 163, and the input end of the wheel leg retracting synchronization valve 162 is connected to the first port of the two-way control wheel leg retracting hydraulic reversing valve.

[0037] Specifically, when the two-way control wheel leg retraction and retraction hydraulic reversing valve 163 is in the middle position, the first port and the second port are disconnected from the P port and the T port, and the oil pressure of the hydraulic oil circuit cannot directly affect the retraction and extension device. When the two-way control wheel leg retraction and retraction hydraulic reversing valve 163 is in the left position, the first port is connected to the P port, and the second port is connected to the T port. In this case, the input end of the wheel leg retraction and extension synchronization valve 162 is connected to the high-pressure oil circuit, so that the N port of each component of the wheel leg retraction and extension hydraulic cylinder assembly 161 connected to the output end of the wheel leg retraction and extension synchronization valve 162 is in a high-pressure state, while the M port is in a low-pressure state. , driving the piston of the wheel-leg retraction and extension hydraulic cylinder assembly 161 to retract upward, thereby realizing the recovery of the UAV's wheel legs; when the two-way control wheel-leg retraction and extension hydraulic reversing valve 163 is in the right position, the first port is connected to the T port, and the second port is connected to the P port. In this case, the input end of the wheel-leg retraction and extension synchronization valve 162 is connected to the low-pressure oil circuit, so that the N port of each component of the wheel-leg retraction and extension hydraulic cylinder assembly 161 connected to the output end of the wheel-leg retraction and extension synchronization valve 162 is in a low-pressure state, and the M port is in a high-pressure state, driving the piston of the wheel-leg retraction and extension hydraulic cylinder assembly 161 to move downward, so as to realize the extension of the UAV's wheel legs.

[0038] like Figure 4-Figure 6 As shown, the present invention also includes a control method applied to the aforementioned detection UAV multi-wheel leg hydraulic servo adaptive system, which includes a UAV take-off process control step S1 and a UAV landing process control step S2.

[0039] The control step S1 of the drone takeoff process specifically includes the following sub-steps:

[0040] S11. Adaptive lifting of UAV wheel legs: The wheel leg lifting force sensors and wheel leg lifting displacement sensors corresponding to each wheel leg of the UAV receive the pressure changes of the wheel legs from the external environment, and realize the adaptive lifting of all UAV wheel legs by changing the working position of the wheel leg lifting electro-hydraulic servo valve through bidirectional control.

[0041] S12, UAV wheel and leg recovery: The control center gives a wheel and leg recovery signal, and realizes the recovery of all UAV wheel and legs by changing the working position of the hydraulic reversing valve that controls the wheel and leg retraction in both directions.

[0042] The control step S2 of the drone landing process specifically includes the following sub-steps:

[0043] S21, UAV wheel legs are extended; the control center gives a wheel leg extension signal, and by changing the working direction of the hydraulic reversing valve that controls the wheel leg retraction and retraction in both directions, all UAV wheel legs are extended.

[0044] S22. Adaptive lifting of UAV wheel legs: The wheel leg lifting force sensors and wheel leg lifting displacement sensors corresponding to each wheel leg of the UAV receive the pressure changes of the wheel legs from the external environment, and realize adaptive lifting of all UAV wheel legs by bidirectionally controlling the change of the working position of the wheel leg lifting electro-hydraulic servo valve.

[0045] In a preferred embodiment of the present invention, when the drone is in the process of taking off, the drone multi-wheel leg hydraulic servo adaptive system first adjusts the height of each wheel leg during the take-off run-up process through the lifting device 15, and then the drone enters a stable flight process, and the retracting device 16 retracts each wheel leg to complete the take-off process. Figure 4As shown in the figure, the working flow chart of the hydraulic servo adaptive system of the UAV multi-wheel leg, during the take-off run-up and taxiing process, the taxiing road surface restricts the seven wheel legs of the UAV, generating pressure signals and distance signals, and the force sensor and displacement sensor transmit the received mechanical signals and displacement signals to the control center of the corresponding restricted wheel leg, driving the corresponding wheel leg to generate corresponding displacement. Taking the first wheel leg hydraulic lifting assembly 151 as an example, when the sliding road surface is smooth and has no bumps, the first wheel leg lifting displacement sensor 1513 maintains a constant distance from the sliding road surface, and the first wheel leg lifting force sensor 1514 gives the first wheel leg control center a constant initial pressure. At this time, the first two-way control wheel leg lifting electro-hydraulic servo valve 1511 of the first wheel leg hydraulic lifting assembly is in an intermediate state, and the first wheel leg does not produce any lifting distance; if a raised position appears on the sliding road surface, when the external sensor of the first wheel leg detects the raised position, the first wheel leg lifting force sensor 1514 receives a positive pressure value, and the first wheel leg lifting displacement sensor 1513 measures the height of the road surface raised and transmits it to the control center of the first wheel leg. The control center of the first wheel leg makes the first two-way control wheel leg lifting electro-hydraulic servo valve 1511 of the first wheel leg hydraulic lifting assembly in the right working state, the first port is connected to the T port, and the second port is connected to the P port. Under the action of hydraulic pressure, the first wheel leg The legs rise, and the rising distance is adjusted according to the protrusion height measured by the first wheel leg lifting displacement sensor 1513. On the contrary, if the sliding road surface is concave, the first wheel leg lifting displacement sensor detects the concave position, and the first wheel leg lifting force sensor 1514 receives a pressure value lower than the normal level. The first wheel leg lifting displacement sensor measures the depth of the concave surface of the road surface and transmits it to the control center of the first wheel leg. The control center of the first wheel leg makes the first two-way control wheel leg lifting electro-hydraulic servo valve of the first wheel leg hydraulic lifting assembly in the left working state, the first port is connected to the P port, and the second port is connected to the T port. Under the action of hydraulic pressure, the first wheel leg is lowered, and the descending distance is adjusted according to the concave depth measured by the first wheel leg lifting displacement sensor 1513. In addition, for the multi-wheel leg hydraulic servo adaptive system of the drone, the lifting direction and lifting distance of the drone's wheel legs can be controlled by external equipment to prevent the stability of the entire drone from being affected by problems in the control center of the local wheel legs.

[0046] In addition, the UAV multi-wheel leg hydraulic servo adaptive system includes seven independent wheel leg control centers, namely the first wheel leg, second wheel leg, third wheel leg, fourth wheel leg, fifth wheel leg, sixth wheel leg and seventh wheel leg, which can be arranged in various lifting states to cope with various sliding surface heights, and the lifting mechanism of each wheel leg is the same as that of the first wheel leg.

[0047] When the UAV completes the takeoff and run-up process and enters a stable flight process, the wheels and legs of the UAV need to be retracted to reduce flight resistance. At this time, the two-way electro-hydraulic servo valves for controlling the lifting of the wheel legs in the lifting device are in the middle position. At this time, the lifting device is in an interrupted state and has no effect on the retraction and extension of the wheel legs of the UAV. When the central control area of ​​the retraction and extension device 16 receives the wheel leg recovery signal, the two-way control wheel leg retraction and extension electro-hydraulic reversing valve 163 is connected to the left position. At this time, the first port is connected to the P port, and the second port is connected to the T port. At this time, under the action of hydraulic pressure, the input end of the wheel leg retraction and extension synchronization valve 162 is connected to the output end of the second port, and the first oil port, the second oil port, the third oil port, the fourth oil port, the fifth oil port, the sixth oil port and the seventh oil port at the output end of the wheel leg retraction and extension synchronization valve 162 are in a high oil pressure state. Taking the first wheel leg retraction and extension hydraulic cylinder assembly 1611 as an example, Figure 1 As shown, the second port of the first wheel leg retraction and extension hydraulic cylinder assembly is connected to the first oil port at the output end of the wheel leg retraction and extension synchronization valve and is in a high-pressure state. The first port of the first wheel leg retraction and extension hydraulic cylinder assembly is connected to the low-pressure oil circuit and is in a low-pressure state. Due to the hydraulic pressure difference, the first wheel leg retraction and extension hydraulic cylinder assembly contracts inward to achieve the recovery of the first wheel leg. The recovery principles of the second wheel leg, third wheel leg, fourth wheel leg, fifth wheel leg, sixth wheel leg and seventh wheel leg are the same as the recovery principle of the first wheel leg and are in a synchronous state.

[0048] In another preferred embodiment of the present invention, when the drone is in the process of landing, the drone multi-wheel leg hydraulic servo adaptive system first extends each wheel leg of the drone through the retracting device 16, and then the drone enters the landing process, and the lifting device 15 adjusts the height of each wheel leg during the landing braking and sliding process to complete the landing process. Figure 5 and Figure 6As shown, during the landing process, the working process of the hydraulic servo adaptive system of the multi-wheel legs of the UAV is that when the UAV is in a normal navigation state, the wheel legs of the UAV are in a retracted state. At this time, the hydraulic reversing valve of the two-way control wheel leg retraction of the retracting and extending device and the two-way control wheel leg lifting and lowering electro-hydraulic servo valve of the lifting device are in the middle position, and the wheel legs of the UAV remain stable; when the UAV enters the landing preparation from a stable flight, the wheel legs of the UAV need to be retracted and extended. During this process, the two-way control wheel leg lifting and lowering electro-hydraulic servo valve of the lifting device is in the middle position, the hydraulic oil circuit is interrupted, and the lifting device has no effect on the wheel legs of the UAV. When the external command regulates the central control area of ​​the retracting and extending device, the hydraulic reversing valve of the two-way control wheel leg retraction of the retracting and extending device is in the right position when the wheel legs send out a signal. The specific impact mode is the same as the above embodiment. At this time, the first port is connected to the T port, and the second port is connected to the P port. At this time, under the action of hydraulic pressure, the input end of the wheel leg retraction and extension synchronization valve is connected to the output end of the first port, and the first oil port, the second oil port, the third oil port, the fourth oil port, the fifth oil port, the sixth oil port and the seventh oil port of the wheel leg retraction and extension synchronization valve output end are in a low oil pressure state. Taking the first wheel leg retraction and extension hydraulic cylinder assembly as an example, the first wheel leg retraction and extension hydraulic cylinder assembly expands outward due to the hydraulic pressure difference, realizing the outward extension of the first wheel leg. The second wheel leg, the third wheel leg, the fourth wheel leg, the fifth wheel leg, the sixth wheel leg and the seventh wheel leg are in a synchronous state with the first wheel leg.

[0049] After the retraction and extension process of the UAV wheel legs is completed, the UAV enters the landing braking and sliding process. At this time, the two-way control hydraulic reversing valve of the retraction and extension device for the wheel legs is in the middle position and stops working, which has no effect on the lifting and lowering of the UAV wheel legs. The lifting device enters the working state. The retraction and extension height of each wheel leg during the landing braking and sliding process of the UAV is determined according to the specific convexity of the sliding road surface. The detailed implementation process is as described in the above embodiment.

[0050] The embodiments described above are only descriptions of the preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A multi-wheeled leg hydraulic servo adaptive system for a detection drone, comprising a driving device, a lifting device and a retracting device, characterized in that: The lifting device and the retracting device are connected in parallel to the driving device, the driving device includes an oil tank, a plunger pump, a first fine filter, an accumulator, a safety stop valve and a second pressure gauge, the third port of the oil tank is connected to the fifth port of the plunger pump, the first port, the second port and the third port of the first fine filter are respectively connected to the first port of the plunger pump, the second pressure gauge and the accumulator; The lifting device comprises a first wheel-leg hydraulically controlled lifting assembly, a second wheel-leg hydraulically controlled lifting assembly, a third wheel-leg hydraulically controlled lifting assembly, a fourth wheel-leg hydraulically controlled lifting assembly, a fifth wheel-leg hydraulically controlled lifting assembly, a sixth wheel-leg hydraulically controlled lifting assembly and a seventh wheel-leg hydraulically controlled lifting assembly, the first wheel-leg hydraulically controlled lifting assembly comprises a two-way control wheel-leg lifting electro-hydraulic servo valve, a wheel-leg lifting hydraulic cylinder, a wheel-leg lifting displacement sensor assembly and a wheel-leg lifting force sensor assembly, the first port and the second port of the two-way control wheel-leg lifting electro-hydraulic servo valve are respectively connected to the first end and the second end of the wheel-leg lifting hydraulic cylinder, the first mounting end and the second mounting end of the piston rod of the wheel-leg lifting hydraulic cylinder are respectively connected to the first wheel-leg lifting displacement sensor and the first wheel-leg lifting force sensor; The retracting and extending device includes a wheel-leg retracting and extending hydraulic cylinder assembly, a wheel-leg retracting and extending synchronous valve, and a two-way control wheel-leg retracting and extending hydraulic reversing valve. The first port of the two-way control wheel-leg retracting and extending hydraulic reversing valve is connected to the input end of the wheel-leg retracting and extending hydraulic cylinder assembly through the wheel-leg retracting and extending synchronous valve, and the second port of the two-way control wheel-leg retracting and extending hydraulic reversing valve is connected to the output end of the wheel-leg retracting and extending hydraulic cylinder assembly.

2. The multi-wheeled leg hydraulic servo adaptive system of the detection UAV according to claim 1 is characterized in that: The wheel-leg retracting and extending hydraulic cylinder assembly comprises a first wheel-leg retracting and extending hydraulic cylinder assembly, a second wheel-leg retracting and extending hydraulic cylinder assembly, a third wheel-leg retracting and extending hydraulic cylinder assembly, a fourth wheel-leg retracting and extending hydraulic cylinder assembly, a fifth wheel-leg retracting and extending hydraulic cylinder assembly, a sixth wheel-leg retracting and extending hydraulic cylinder assembly and a seventh wheel-leg retracting and extending hydraulic cylinder assembly, a first mounting end and a second mounting end of a piston rod of the first wheel-leg retracting and extending hydraulic cylinder assembly are respectively connected to the first wheel-leg retracting and extending displacement sensor and the first wheel-leg retracting and extending force sensor, and the first wheel-leg retracting and extending hydraulic cylinder assembly realizes the retraction and extension of the first wheel leg of the UAV through the movement of the piston.

3. The multi-wheeled leg hydraulic servo adaptive system of the detection UAV according to claim 1 or 2 is characterized in that: The first wheel leg retracting hydraulic cylinder assembly, the second wheel leg retracting hydraulic cylinder assembly, the third wheel leg retracting hydraulic cylinder assembly, the fourth wheel leg retracting hydraulic cylinder assembly, the fifth wheel leg retracting hydraulic cylinder assembly, the sixth wheel leg retracting hydraulic cylinder assembly and the seventh wheel leg retracting hydraulic cylinder assembly have the same structure and the same connection control method.

4. The multi-wheeled leg hydraulic servo adaptive system of the detection drone according to claim 1 is characterized in that: The first wheel-leg hydraulically controlled lifting assembly controls the lifting distance of the first wheel-leg through the movement of the piston rod. The wheel-leg hydraulically controlled lifting assemblies in the lifting device are connected in parallel with each other, and the wheel-leg hydraulically controlled lifting assemblies can be controlled separately, and the structure and connection control method of each wheel-leg hydraulically controlled lifting assembly are the same.

5. The multi-wheeled leg hydraulic servo adaptive system of the detection UAV according to claim 1 is characterized in that: The driving device also includes a first cooler, a second cooler, a first pressure gauge, a relief valve, a thermometer, a heater, a hydraulic gauge, a servo motor and a coarse filter. The first port, the second port, the fourth port, the fifth port, the sixth port, the seventh port, the eighth port and the ninth port of the oil tank are respectively connected to the first cooler, the first pressure gauge, the coarse filter, the relief valve, the thermometer, the heater, the second cooler and the hydraulic gauge. The second port, the third port, the fourth port and the fifth port of the plunger pump are connected to the relief valve, the output end of the servo motor, the coarse filter and the third port of the oil tank in sequence. The second port, the third port, the fourth port and the fifth port of the first fine filter are respectively connected to the second pressure gauge, the accumulator, the lifting device and the retracting device; the accumulator, the safety stop valve and the second pressure gauge constitute a hydraulic pressure monitoring device.

6. A control method for the multi-wheeled leg hydraulic servo adaptive system of a detection UAV according to any one of claims 1 to 5, characterized in that: It includes a control step S1 for the drone take-off process and a control step S2 for the drone landing process; The control step S1 of the drone takeoff process specifically includes the following sub-steps: S11, adaptive lifting of wheel legs of UAV: ​​the wheel leg lifting force sensor and the wheel leg lifting displacement sensor corresponding to each wheel leg of the UAV receive the pressure change of the wheel leg by the external environment, and realize the adaptive lifting of all wheel legs of the UAV by changing the working position of the bidirectional control wheel leg lifting electro-hydraulic servo valve; S12, UAV wheel leg recovery: the control center gives a wheel leg recovery signal, and realizes the recovery of all UAV wheel legs by changing the working direction of the hydraulic reversing valve for bidirectionally controlling wheel leg retraction; The control step S2 of the drone landing process specifically includes the following sub-steps: S21, the UAV wheel legs are released; the control center gives a wheel leg release signal, and all the UAV wheel legs are released by changing the working position of the hydraulic reversing valve for bidirectionally controlling the wheel leg retraction; S22. Adaptive lifting of UAV wheel legs: The wheel leg lifting force sensor and the wheel leg lifting displacement sensor corresponding to each wheel leg of the UAV receive the pressure changes of the wheel legs from the external environment, and realize adaptive lifting of all UAV wheel legs by changing the working position of the bidirectionally controlled wheel leg lifting electro-hydraulic servo valve.

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