A control system for unmanned aerial vehicle launch and braking and a control method thereof

Abstract

The application belongs to the technical field of aircraft catapult take-off support equipment, and particularly relates to a control system for unmanned aerial vehicle catapult braking and a control method thereof. The control system for unmanned aerial vehicle catapult braking optimizes the design of the electric control part in the system in cooperation with the mechanical structure of the braking execution device, brakes and resets the launch vehicle slidingly arranged on the power platform by setting the control assembly including the double-redundancy controller, the electromagnetic valve group, the photoelectric sensor, the angular displacement encoder, the proportional valve group, the hydraulic pump, the hydraulic oil tank and the pressure accumulator. The control method for unmanned aerial vehicle catapult braking adopts the double-redundancy control mode and has high reliability.

Description

Technical Field

[0001] This invention belongs to the technical field of aircraft catapult takeoff support equipment, specifically relating to a control system and control method for catapult braking of unmanned aerial vehicles (UAVs). Background Technology

[0002] Catapult launch is an important method for drone takeoff. Common drone catapult launch methods include elastic catapult, pneumatic-hydraulic catapult, gas catapult, and electromagnetic catapult.

[0003] For example, Chinese invention patent with patent (application) number 201510983657.9 discloses a hydraulic catapult system for unmanned aerial vehicles (UAVs), which provides strong driving force and buffer braking force through hydraulics, and can adapt to the usage requirements of different UAV takeoff weights and takeoff speeds.

[0004] However, after the aircraft is launched, the launching device needs to be braked and reset to meet the requirements of the launch vehicle and the shuttle for repeated aircraft launches. The braking device and method are a critical part of the development of high-performance catapult systems, but there is limited publicly available technical information on this aspect, and the technological layout is relatively weak. Summary of the Invention

[0005] This invention addresses the relatively weak braking technology of aircraft catapult launch devices in the existing technology by proposing a control system and method for UAV catapult braking. The electronic control part of the system is optimized in conjunction with the mechanical structure of the braking actuator. By setting up control components including a dual-redundant controller and solenoid valve group, photoelectric sensor, angular displacement encoder, proportional valve group, hydraulic pump, hydraulic oil tank and accumulator, the launch vehicle slidingly mounted on the power platform is braked and reset.

[0006] The specific implementation details of this invention are as follows: I. This invention provides a control system for the ejection braking of unmanned aerial vehicles (UAVs).

[0007] A control system for launching and braking unmanned aerial vehicles (UAVs) is connected to a braking actuator including a hydraulic brake, an electromagnetic clutch, and a reset drive. The system is used to brake and reset a launch vehicle that is slidably mounted on a power platform by means of a rope-winding drum whose shaft end is fixedly connected to a friction disc and a brake rope wound on the rope-winding drum. The hydraulic brake corresponds to the position of the friction disc whose shaft end is fixedly connected to the rope-winding drum, and the reset drive is engaged and disengaged from the rope-winding drum through the electromagnetic clutch. The control system includes a dual-redundant controller and solenoid valve group, photoelectric sensor, angular displacement encoder, proportional valve group, hydraulic pump, hydraulic oil tank, and accumulator; The photoelectric sensor is disposed on the side of the rope winding drum, independent of the rotatable rope winding drum, and is used to collect the positioning signal of the brake rope exiting the drum; the angular displacement encoder is disposed on the shaft end of the rope winding drum and rotates together with the rotatable rope winding drum, and is used to obtain the rotational displacement of the rope winding drum; the hydraulic oil tank is connected to the hydraulic brake through the hydraulic pump, and is used to provide a hydraulic power source; a proportional valve group for total pressure regulation and an accumulator for pressure holding are also provided on the pipeline between the hydraulic pump and the hydraulic brake; the solenoid valve group includes multiple solenoid valves, and each hydraulic brake and each electromagnetic clutch is connected to one solenoid valve; The dual-redundant controller is electrically connected to the photoelectric sensor and the angular displacement encoder, respectively, and is used to use the positioning signal collected by the photoelectric sensor or the rotational displacement obtained by the angular displacement encoder as the braking criterion. The dual-redundant controller is electrically connected to each solenoid valve in the solenoid valve group, and is used to brake the friction disc by pressurizing the hydraulic brake, and to disconnect / connect the rope winding drum from the reset drive by gaining / losing power through the electromagnetic clutch. The dual-redundant controller is also connected to the reset drive, and through the reset drive and the electromagnetic clutch, the rope winding drum is rotated to wind up the rope, and the launch vehicle is reset by pulling the brake rope.

[0008] Furthermore, in order to better realize the present invention, the dual-redundant controller mainly consists of two CPU controllers, and the fiber optic communication interfaces of the two CPU controllers are interconnected through optical cables to perform redundant data communication.

[0009] Furthermore, in order to better realize the present invention, the optical fiber communication interface adopts a standard LC optical fiber interface with a communication rate of up to 1Gbps, ensuring that the link switching time of the dual-redundancy controller does not exceed 10ms.

[0010] Furthermore, in order to better realize the present invention, the control system also includes a heat sink for heat dissipation.

[0011] Furthermore, in order to better realize the present invention, the reset drive adopts a servo drive mechanism, including a reset motor and a reducer connected to each other; the reset motor is connected to the electromagnetic clutch through the reducer.

[0012] Furthermore, in order to better realize the present invention, the electromagnetic clutch engages when the electromagnetic valve connected to the electromagnetic clutch is energized and disengages when the electromagnetic valve connected to the electromagnetic clutch is de-energized; or, the electromagnetic clutch engages when the electromagnetic valve connected to the electromagnetic clutch is de-energized and disengages when the electromagnetic valve connected to the electromagnetic clutch is energized.

[0013] II. This invention provides a control method for catapult braking of unmanned aerial vehicles (UAVs).

[0014] A control method for launching and braking unmanned aerial vehicles (UAVs) employs the aforementioned control system to brake and reset a launch vehicle slidably mounted on a power platform via a braking actuator. Specifically, the control method first uses the positioning signal acquired by a photoelectric sensor or the rotational displacement obtained by an angular displacement encoder as the braking criterion. Then, when the braking condition is met, the dual-redundancy controller controls the hydraulic brake to pressurize via a solenoid valve connected to the hydraulic brake to grip the friction disc for braking. After braking is completed, the dual-redundancy controller controls the electromagnetic clutch to actuate via a solenoid valve connected to the electromagnetic clutch, enabling the reset drive to engage with the rope winding drum. Subsequently, the dual-redundancy controller sends a control command to the reset drive, which drives the rope winding drum to reverse and the retracted brake rope to reset the launch vehicle.

[0015] Furthermore, in order to better realize the present invention, before starting the launch vehicle used for launching the UAV, the dual-redundant controller, solenoid valve group, proportional valve group, hydraulic pump, and accumulator are started. The dual-redundant controller controls the operation of the solenoid valve group, proportional valve group, hydraulic pump, and accumulator. On the one hand, the total pressure is adjusted to the predetermined pressure through the proportional valve group and the pressure is maintained by the accumulator. On the other hand, the electromagnetic clutch is controlled by the solenoid valve group to ensure that the rope winding drum and the reset drive are disengaged.

[0016] Furthermore, in order to better realize the present invention, the rotational displacement obtained by the angular displacement encoder set at the end of the winding drum shaft is used as the primary braking criterion. If the angular displacement encoder fails, the positioning signal collected by the photoelectric sensor set on the side of the winding drum is used as the secondary braking criterion.

[0017] Furthermore, in order to better realize the present invention, when braking is performed using the control system, the braking criterion is dynamically adjusted according to the braking response lag distance to perform lag compensation.

[0018] It should be noted that in this invention, "aircraft" is a general term for both "unmanned aerial vehicles" and "manned aircraft." This invention applies to both "unmanned aerial vehicles" and "manned aircraft," but is not limited to "unmanned aerial vehicles."

[0019] The present invention has the following beneficial effects.

[0020] The UAV ejection braking control system of the present invention optimizes the electronic control part of the system in conjunction with the mechanical structure of the braking actuator. By setting up control components including a dual-redundant controller and solenoid valve group, photoelectric sensor, angular displacement encoder, proportional valve group, hydraulic pump, hydraulic oil tank and accumulator, the system brakes and resets the launch vehicle that is slidably mounted on the power platform.

[0021] The UAV ejection braking control method described in this invention adopts a dual-redundant control approach, sets multiple redundant braking criteria, and performs braking response lag compensation for control, resulting in high reliability. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the connection structure of the brake rope, the drum rope winding module, the brake actuator, and the brake system in this invention.

[0023] Figure 2 This is a three-dimensional structural diagram of the UAV catapult system in this invention.

[0024] Figure 3 This is a schematic diagram showing the correspondence between the main logic and the device control logic flow in this invention.

[0025] Figure 4 This is a schematic diagram of the main logic flow in this invention.

[0026] Figure 5 This is a flowchart of the redundancy criterion control strategy in this invention.

[0027] Figure 6 This is a schematic diagram showing the connection between the two CPUs in the dual-redundant controller of this invention.

[0028] Figure 7 This is a schematic diagram of the variable speed recovery control curve in this invention.

[0029] Among them, 1. Power platform; 2. Launch vehicle; 3. Braking platform; 12. Braking rope; 31. Dual-redundant controller; 32. Radiator; 33. Solenoid valve assembly; 36. Photoelectric sensor; 38. Angular displacement encoder; 312. Proportional valve assembly; 313. Hydraulic pump; 314. Hydraulic oil tank; 315. Accumulator; 141. Hydraulic brake; 154. Friction disc; 155. Rope winding drum; 171. Electromagnetic clutch; 172. Reducer; 173. Reset motor. Detailed Implementation

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the described embodiments are only some embodiments of the present invention, and not all embodiments, and therefore should not be regarded as a limitation on the scope of protection. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1:

[0032] First, it should be noted that the control system and control method described in this invention can only better achieve their intended functions when used in conjunction with a drone catapult system of a specific structure. Therefore, this embodiment first describes the main technical contents related to braking in this specific drone catapult system.

[0033] like Figure 1 , Figure 2 The UAV launch system of the present invention includes a power platform 1, a launch vehicle 2, a brake rope 12, a roller rope winding module, a braking actuator, and a braking system. The roller rope winding module includes a rope winding roller 155 and a friction disc 154 fixed to the shaft end of the rope winding roller 155. The fixed end of the brake rope 12 is disposed on the rope winding roller 155, and the brake rope 12 is wound in an orderly manner around the cylinder of the rope winding roller 155 and then connected to the launch vehicle 2. Typically, the brake rope 12 is a damping rope. The launch vehicle 2 is slidably mounted on the power platform 1. During the launch phase, the power acceleration system on the power platform 1 drives the launch vehicle 2 to accelerate in preparation for launch, at which time the rope winding roller 155 rotates clockwise, resulting in the brake rope 12 being released. During the braking phase, the power acceleration system no longer provides launch power; instead, the braking system, through the braking actuator, drives the rope winding roller 155 in the roller rope winding module to rotate counterclockwise, resulting in the brake rope 12 being wound up.

[0034] Furthermore, the braking actuator includes a hydraulic brake 141, an electromagnetic clutch 171, and a reset drive. The hydraulic brake 141 is positioned corresponding to the friction disc 154 fixed at the shaft end of the rope winding drum 155. When the hydraulic brake 141 engages, it performs rotational friction energy absorption braking. The reset drive is engaged and disengaged from the rope winding drum 155 via the electromagnetic clutch 171. When the electromagnetic clutch 171 is engaged, the reset drive operates, causing the brake rope 12 to drive the launch vehicle 2 back to its original ready-to-launch position, preparing for the next launch.

[0035] This embodiment provides a control system for the ejection braking of an unmanned aerial vehicle (UAV), which is connected to a braking actuator including a hydraulic brake 141, an electromagnetic clutch 171, and a reset drive. The system is used to brake and reset the launch vehicle 2, which is slidably mounted on a power platform 1, by means of a brake rope 12 wound on the brake rope 155 and a friction disc 154 fixed at the end of the brake rope 155. The hydraulic brake 141 corresponds to the friction disc 154 fixed at the end of the brake rope 155, and the reset drive is engaged and disengaged from the brake rope 155 through the electromagnetic clutch 171. The control system includes a dual-redundant controller 31, a solenoid valve group 33, a photoelectric sensor 36, an angular displacement encoder 38, a proportional valve group 312, a hydraulic pump 313, a hydraulic oil tank 314, and an accumulator.

[0036] The photoelectric sensor 36 is disposed on the side of the rope winding drum 155 and is independent of the rotatable rope winding drum 155, and is used to collect the positioning signal of the brake rope 12 exiting the drum; the angular displacement encoder 38 is disposed on the shaft end of the rope winding drum 155 and rotates together with the rotatable rope winding drum 155, and is used to obtain the rotational displacement of the rope winding drum 155; the hydraulic oil tank 314 is connected to the hydraulic brake 141 through the hydraulic pump 313, and is used to provide a hydraulic power source; a proportional valve group 312 for total pressure regulation and an accumulator for pressure holding are also provided on the pipeline between the hydraulic pump 313 and the hydraulic brake 141; the solenoid valve group 33 includes multiple solenoid valves, and each hydraulic brake 141 and each electromagnetic clutch 171 is connected to one solenoid valve.

[0037] The dual-redundant controller 31 is electrically connected to the photoelectric sensor 36 and the angular displacement encoder 38, respectively, and is used to use the positioning signal collected by the photoelectric sensor 36 or the rotational displacement obtained by the angular displacement encoder 38 as the braking criterion. The dual-redundant controller 31 is electrically connected to each solenoid valve in the solenoid valve group 33, and is used to brake the friction disc 154 by pressurizing the hydraulic brake 141, and to disconnect / connect the rope winding drum 155 from the reset drive when the electromagnetic clutch 171 is energized / de-energized. The dual-redundant controller 31 is also connected to the reset drive, and through the reset drive and the electromagnetic clutch 171, the rope winding drum 155 is rotated to wind up the rope, and the launch vehicle 2 is reset by the brake rope 12.

[0038] The UAV ejection braking control system described in this embodiment solves the problem of how to quickly brake and stop the launch vehicle 2 carrying the UAV during high-speed forward movement when the UAV is performing an ejection mission.

[0039] Example 2:

[0040] This embodiment is an optimized design based on Embodiment 1. The dual-redundancy controller 31 mainly consists of two CPU controllers, which simultaneously run the braking control software. The fiber optic communication interfaces of the two CPU controllers are interconnected via optical cables for redundant data communication. The two links operate redundantly; when one link fails and the other is functioning correctly, the system switches to the redundant link. While the two CPU controllers constitute the hardware configuration for dual-redundancy control, software support is also required to truly achieve it.

[0041] Furthermore, the optical fiber communication interface adopts a standard LC optical fiber interface with a communication rate of up to 1Gbps, ensuring that the link switching time of the dual-redundancy controller 31 does not exceed 10ms. A switching time of no more than 10ms improves the reliability of continuous system operation. Figure 6 As shown, the two CPU controllers are denoted as the master CPU and the slave CPU. The two fiber optic interfaces of the master CPU are denoted as: Channel 1 transmitter, TX1; Channel 2 receiver, RX2. The two fiber optic interfaces of the slave CPU are denoted as: Channel 2 transmitter, TX2; Channel 1 receiver, RX1. The channel 1 transmitter TX1 is connected to the channel 1 receiver RX1; the channel 2 transmitter TX2 is connected to the channel 2 receiver RX2.

[0042] In another specific embodiment, an external system control cabinet is typically used to protect the dual-redundant controller 31. Setting up a control cabinet for protection within the control system is a conventional technique in this field and can be adapted to meet specific needs; therefore, it will not be elaborated further.

[0043] In another specific embodiment, the control system further includes a heat sink 32 for heat dissipation. During operation, the heat dissipated by various components needs to be dissipated promptly to control the ambient temperature and ensure the normal operation of the entire control system. Incorporating a heat sink 32 into the control system is a conventional technique in the art and can be adapted to specific needs; therefore, it will not be described in detail further.

[0044] The other parts of this embodiment are the same as those in Embodiment 1, so they will not be described again.

[0045] Example 3:

[0046] This embodiment is an optimized design based on Embodiment 1 or Embodiment 2. The reset drive adopts a servo drive mechanism, including a reset motor 173 and a reducer 172 connected to each other; the reset motor 173 is connected to the electromagnetic clutch 171 through the reducer 172.

[0047] When the electromagnetic clutch 171 is energized / de-energized, it disconnects / engages the rope winding drum 155 with the reset drive, representing two main types of corresponding structures: The first type is where the electromagnetic clutch 171 engages when the solenoid valve connected to it is energized, and disengages when the solenoid valve is de-energized; the second type is where the electromagnetic clutch 171 engages when the solenoid valve connected to it is de-energized, and disengages when the solenoid valve is energized. These two types of structures are typically determined by the installation method of the solenoid valve used to control the switching of the working state of the electromagnetic clutch 171. Both types of structures are conventional techniques in this field and will not be described in detail further.

[0048] In another specific implementation, such as Figure 2 As shown, two sets of roller rope winding modules are provided. Each set of roller rope winding modules has one rope winding roller 155. Each rope winding roller 155 has a friction disc 154 at each of its two shaft ends, and each friction disc 154 has a hydraulic brake 141 positioned on either side of its axis. Therefore, Figure 2 The schematic diagram of the internal structure of the braking platform 3 shown indicates that it has eight hydraulic brakes 141. At this time, the solenoid valve group 33 is equipped with nine solenoid valves, denoted as: DCF0, DCF1, DCF2, DCF3, DCF4, DCF5, DCF6, DCF7, and DCF8. Solenoid valves DCF1, DCF2, DCF3, DCF4, DCF5, DCF6, DCF7, and DCF8 are electrically connected to each of the eight hydraulic brakes 141 in a one-to-one correspondence; while solenoid valve DCF0 is electrically connected to the accumulator. The eight hydraulic brakes 141 correspond to eight branches: 1#, 2#, 3#, 4#, 5#, 6#, 7#, and 8#; each branch is equipped with one solenoid valve, in a one-to-one correspondence.

[0049] The other parts of this embodiment are the same as those in Embodiment 1 or Embodiment 2, so they will not be described again.

[0050] Example 4:

[0051] This embodiment provides a control method for the ejection braking of an unmanned aerial vehicle (UAV). The control system described in Embodiment 1 uses a braking actuator to brake and reset the launch vehicle 2, which is slidably mounted on the power platform 1. The reset drive employs a servo drive mechanism.

[0052] In this embodiment, the control method first uses the positioning signal collected by the photoelectric sensor 36 or the rotational displacement obtained by the angular displacement encoder 38 as the braking criterion; then, when the braking condition is reached, the dual-redundancy controller 31 controls the hydraulic brake 141 to pressurize through the solenoid valve connected to the hydraulic brake 141 to grip the friction disc 154 for braking; after braking is completed, the dual-redundancy controller 31 controls the electromagnetic clutch 171 to operate through the solenoid valve connected to the electromagnetic clutch 171, so that the reset drive can engage with the rope winding drum 155. Then, the dual-redundancy controller 31 sends a control command to the reset drive, and the reset drive drives the rope winding drum 155 to reverse and the retracted brake rope 12 to pull the launch vehicle 2 to reset.

[0053] Example 5:

[0054] Based on Embodiment 4, the main logic of the control method corresponds to the braking and reset processes in the device control logic. The corresponding content of the braking process in the main logic of the control method and the device control logic is as follows: Figure 3 , Figure 4 As shown in Table 1.

[0055]

[0056] The main logic of the control method corresponds to the reset process in the device control logic, such as... Figure 3 , Figure 4 As shown in Table 2.

[0057]

[0058] In the figure, "brake" refers to the general term for hydraulic brake 141, electric brake, and pneumatic brake. Although the control system provided in Embodiment 1 preferably uses hydraulic brake 141, in practice, using electric brake or pneumatic brake instead of hydraulic brake 141 and making adaptive adjustments to the power source can also achieve a similar braking function.

[0059] Similarly, in the figure, "clutch" refers to the general term for hydraulic clutches, electric clutches, and pneumatic clutches. Although the control system provided in Embodiment 1 preferably uses an electromagnetic clutch 171, in practice, a similar on / off function can be achieved by using a hydraulic clutch or a pneumatic clutch instead of an electromagnetic brake and making adaptive adjustments to the power source.

[0060] The "contactor" in the figure includes the electromagnetic relay in this embodiment, but it can also be other electronic switches. This is a conventional technique in the field, so it will not be described in detail here.

[0061] It should be noted that the radiator 32 can be directly installed or externally configured. If the radiator 32 is directly installed in the control system, a solenoid valve for controlling the operation of the radiator 32 needs to be added. This is a conventional technique in the field and will not be described in detail here.

[0062] In addition, the overall control signals, including the overall control catapult start signal, are usually issued by the overall control center of the entire aircraft catapult system. In this embodiment, the dual-redundant controller 31 can receive and respond to such signals. Therefore, the overall control signals are not part of the technical content of this invention and will not be described in detail.

[0063] Example 6:

[0064] This embodiment optimizes the control method based on any one of Embodiments 1, 2, 3, 4, and 5 to improve control accuracy.

[0065] Before the launch vehicle 2 used for launching UAVs is started, the dual-redundant controller 31, solenoid valve group 33, proportional valve group 312, hydraulic pump 313, and accumulator are started. The dual-redundant controller 31 controls the operation of solenoid valve group 33, proportional valve group 312, hydraulic pump 313, and accumulator. On the one hand, the total pressure is adjusted to the predetermined pressure through proportional valve group 312 and the pressure is maintained by accumulator. On the other hand, the electromagnetic clutch 171 is controlled by solenoid valve group 33 to ensure that the rope winding drum 155 and the reset drive are disengaged.

[0066] During the ejection process, it is determined in advance whether the UAV can reach the takeoff speed when the launch vehicle 2 reaches the braking position. The pressure adjustment is based on whether the UAV can take off, and the pressure is adjusted through the proportional valve group 312 set in each proportional valve of each pipeline.

[0067] In this embodiment, "using the position signal collected by the photoelectric sensor 36 or the rotational displacement obtained by the angular displacement encoder 38 as the braking criterion" means that either the position signal collected by the photoelectric sensor 36 or the rotational displacement obtained by the angular displacement encoder 38 can be used as the braking criterion. That is, the dual-redundancy controller 31 uses either the position signal collected by the photoelectric sensor 36 or the rotational displacement obtained by the angular displacement encoder 38 as the braking criterion to enter the braking mode. At this time, the order of the position signal collected by the photoelectric sensor 36 and the rotational displacement obtained by the angular displacement encoder 38 is not limited; the dual-redundancy controller 31 will enter the braking mode as long as it detects either of the two braking criteria.

[0068] To further improve the accuracy of braking control, in another specific embodiment, the rotational displacement acquired by the angular displacement encoder 38 located at the shaft end of the rope winding drum 155 is used as the primary braking criterion. If the angular displacement encoder 38 fails, the positioning signal collected by the photoelectric sensor 36 located on the side of the rope winding drum 155 is used as the secondary braking criterion. In this case, the "positioning signal collected by the photoelectric sensor 36" has higher priority than the "rotational displacement acquired by the angular displacement encoder 38". Therefore, a multi-redundancy criterion strategy is adopted to ensure reliable braking of the system.

[0069] The braking criterion is also a judgment condition. When the judgment condition is triggered, the dual-redundancy controller 31 issues a control command to activate the solenoid valve in the solenoid valve group 33. The hydraulic brake 141 applies pressure to grip the friction disc 154 and brake until the launch vehicle 2 stops moving forward.

[0070] It should be noted that, in another embodiment, a wireless piezoelectric acceleration sensor is installed on the vehicle body of the launch vehicle 2, which is configured to measure the operating speed of the launch vehicle 2 in real time. When the launch vehicle 2 reaches the expected braking position set by the first-level braking criterion, the control system determines whether the speed of the launch vehicle 2 at this time meets the UAV launch speed requirement. If the UAV cannot be launched, the control system needs to perform braking according to the total weight of the launch vehicle 2 plus the aircraft, and the main branch pressure of the hydraulic pipeline in the control system is set to Y2; if the UAV is successfully launched, the control system performs braking according to the weight of the launch vehicle 2, and the main branch pressure of the hydraulic pipeline in the control system is set to Y1, where Y1<Y2. If the control system still performs braking according to the total weight of the launch vehicle 2 plus the aircraft after the UAV is successfully released, great overload impact will be caused to the structure of the launch vehicle 2, resulting in structural looseness of the launch vehicle 2 and affecting the service life of the launch vehicle 2.

[0071] As Figure 5 shown, the first-level braking criterion is that when the launch vehicle 2 moves to the expected braking position S1, the hydraulic brake 141 pressurizes to brake the friction disc 154, the rope winding drum 155 starts to rotate at a reduced speed, slowly pays out the braking rope 12, and the launch vehicle 2 decelerates to a stop through the braking rope 12 hung below its vehicle body. The second-level braking criterion is that when the launch vehicle 2 moves to the expected braking position S2, the hydraulic brake 141 pressurizes to brake the friction disc 154, the rope winding drum 155 starts to rotate at a reduced speed, slowly pays out the rope, and the launch vehicle 2 decelerates to a stop through the braking rope 12 hung below its vehicle body. Generally, the braking rope 12 is a high-strength nylon rope. Further, the expected braking position S1 is less than the expected braking position S2, and the second-level braking criterion plays a protective role to prevent the system from failing to brake and the launch vehicle 2 rushing out of the runway when the angular displacement encoder 38 malfunctions, and the hydraulic system does not receive the hydraulic braking signal after the launch vehicle 2 reaches the braking position set by the first-level braking criterion. After the first-level braking criterion is triggered, the second-level braking criterion can still be triggered. The angular displacement encoder 38, also called angle encoder, is a type of displacement sensor.

[0072] Other parts of this embodiment are the same as any one of Embodiment 1, Embodiment 2, Embodiment 3, Embodiment 4 and Embodiment 5, so they will not be repeated here.

[0073] Example 7:

[0074] In this embodiment, the control method is optimally designed based on Embodiment 4, Embodiment 5 or Embodiment 6.

[0075] As Figure 2 shown, two sets of drum rope winding modules are provided, each set of drum rope winding module is provided with one rope winding drum 155, two shaft ends of each rope winding drum 155 are respectively provided with one friction disc 154, and each friction disc 154 is correspondingly provided with one hydraulic brake 141 on the left and right along its axis. Therefore, Figure 2 In the schematic diagram of the internal structure of the braking platform 3 shown, two sets of roller rope winding modules are equipped with two sets of reset modules and eight hydraulic brakes 141. At this time, the solenoid valve group 33 is equipped with nine solenoid valves, denoted as: solenoid valve DCF0, solenoid valve DCF1, solenoid valve DCF2, solenoid valve DCF3, solenoid valve DCF4, solenoid valve DCF5, solenoid valve DCF6, solenoid valve DCF7, and solenoid valve DCF8. Solenoid valves DCF1, DCF2, DCF3, DCF4, DCF5, DCF6, DCF7, and DCF8 are electrically connected to the eight hydraulic brakes 141 in a one-to-one correspondence; while solenoid valve DCF0 is electrically connected to the accumulator.

[0076] Taking the catapult launch of a 1.3-ton drone as an example, the control method includes the following specific steps: Step 1: Control system preparation phase, confirm information such as launch vehicle 2 number, weight, and weight of the UAV it carries; Step 2: Adjust the pressure of the relief valve in the proportional valve group 312 to 11 MPa, and adjust the pressure of the other proportional valves to 10 MPa; Step 3: De-energize solenoid valve DCF0 to ensure complete pressure release inside the accumulator; Step 4: Start the hydraulic pump 313 and radiator 32, and the hydraulic system will start working; Step 5: The solenoid valve DCF0 is energized, the accumulator is pressurized to 10 MPa, and the system maintains pressure; Step 6: Electromagnetic clutch 171 is de-energized, and the winding drum and reducer 172 disengage; Step 7: Control system ejection phase, receive the UAV ejection mission launch signal; Step 8: Determine in advance whether the UAV can reach takeoff speed when the launch vehicle 2 reaches the braking position; Step 9: Based on whether the drone can take off, adjust the pressure value of the proportional valve on each branch of the hydraulic system to change the magnitude of the braking force acting on the friction disc 154. Step 10: During the braking phase of the control system, based on the detection signal of the photoelectric sensor 36 or the displacement calculated by the angular displacement encoder 38 as the judgment condition, the eight solenoid valves DCF1-DCF8 are energized, and the corresponding hydraulic brakes 1#-8# are pressurized to the working pressure to brake the friction disc 154. Step 11: After the launch vehicle 2 stops, de-energize the eight solenoid valves DCF0-DCF8, release the pressure of the hydraulic brake 141 and the accumulator, and shut down the hydraulic pump 313 and the radiator 32. Step 12: During the control system recovery phase, the electromagnetic clutch 171 is energized, and the winding drum and reducer 172 are connected.

[0077] Step 13: When the reset servo motor is powered on, it can perform dual-axis synchronous control and adopt a variable speed recovery method to flexibly wind the brake rope 12 back onto the winding rope drum 155 until the launch vehicle 2 returns to the origin and the reset servo motor stops moving.

[0078] like Figure 7 As shown, the variable speed recovery method is divided into two stages: high-speed recovery and low-speed recovery.

[0079] In another specific embodiment, an electronic cam function is used to achieve dual-axis synchronous control. After the cam command is issued, the cam function is immediately activated with the current main shaft position as the start position, issuing motion commands to the cam main shaft to drive its movement. At this time, the cam driven shaft performs corresponding linkage actions. When the main shaft reciprocates within the effective stroke range of the cam, the driven shaft also performs reciprocating linkage actions. During the recovery process of launch vehicle 2, the left and right heading electromagnetic clutches 171 are first energized and engaged, connecting the rope winding drum 155 and the servo motion mechanism. Then, the recovery process is divided into two stages: high-speed recovery and low-speed recovery. When the torque in the low-speed recovery stage exceeds the set torque threshold of the reset motor 173, the reset motor 173 stops moving, and the recovery process of launch vehicle 2 ends. The trigger condition for stopping the reset motor 173 at the end of the recovery is that the torque of the reset motor 173 exceeds the set threshold. If the entire recovery process is carried out at high speed, the electromagnetic clutch 171 will experience severe gear wear due to inertia at the moment the reset motor 173 stops, which will significantly reduce the service life of the electromagnetic clutch 171 over time. Using a variable speed recovery method can solve this problem.

[0080] The other parts of this embodiment are the same as any one of embodiments 4-6, so they will not be described again.

[0081] Example 8:

[0082] This embodiment optimizes the control method based on any one of Embodiments 4-7.

[0083] In this embodiment, when the control system is used for braking, the braking criterion is dynamically adjusted according to the braking response lag distance to perform lag compensation.

[0084] The parameters involved in the lag compensation are as follows: The signal response delay time t1 of the angular displacement encoder 38 is 1 / p = 1 / 2500 = 0.4ms, where p is the number of output pulses per revolution of the angle encoder; The signal response delay time T1 of the photoelectric sensor 36 is T1 = 1 / f = 1 / 3000 = 0.3ms, where f is the response frequency of the photoelectric sensor 36; When the control system code size is calculated as 50,000 instructions, the CPU operation delay time t2 = 50,000 * 0.02 = 1 ms; The response delay time of the digital output module is t3 = 2ms; Solid-state relay response delay time t4 = 1ms; The energizing time of solenoid valve assembly 33 is t5 = 40ms; The hydraulic cylinder of the brake has a stroke of 2mm and a volume of 0.01L. The hydraulic system flow rate is 50L / min. The time required for the 8 brakes to extend is t6=96ms. The bulk modulus of hydraulic oil is K = -(V / ΔV)*Δp. The bulk modulus K is taken as 1 GMPa, the pressure change rate Δp = 10 MPa, and the oil volume in the pipeline is taken as 1 L. The calculated volume change rate ΔV = 0.01 L. When the hydraulic brake 141 pressure builds up to 10 MPa, the required time t7 = 12 ms.

[0085] When the system brakes, taking the actual distance traveled by the catapult vehicle reaching 70m, the first-level criterion condition is triggered, and the hydraulic brake 141 begins braking; and the actual distance traveled by the catapult vehicle reaching 80m, the second-level criterion condition is triggered, and the hydraulic brake 141 begins braking, as an example, the expected braking distance triggered by the first-level criterion condition should be set as follows: (Calculated when the catapult vehicle's speed reaches 70m / s) S1= 70-v*( t1+ t2+ t3+ t4+ t5+ t6+ t7)=70-70*0.1524=59.332m; The expected braking distance triggered by the secondary criterion condition should be set as follows: S2=80- v*( T1+ t2+ t3+ t4+ t5+ t6+ t7)=80-70*0.1523=69.339m.

[0086] The other parts of this embodiment are the same as any one of embodiments 4-7, so they will not be described again.

[0087] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A control system for launching and braking unmanned aerial vehicles (UAVs), connected to a braking actuator including a hydraulic brake (141), an electromagnetic clutch (171), and a reset drive, for braking a rope roller (155) with a friction disc (154) fixed at the end of the brake shaft and braking and resetting a launch vehicle (2) slidably mounted on a power platform (1) via a brake rope (12) wound on the rope roller (155); the hydraulic brake (141) corresponds to the friction disc (154) with the end shaft fixed to the rope roller (155), and the reset drive is engaged and disengaged from the rope roller (155) via the electromagnetic clutch (171); Its features are: The control system includes a dual-redundant controller (31), a solenoid valve group (33), a photoelectric sensor (36), an angular displacement encoder (38), a proportional valve group (312), a hydraulic pump (313), a hydraulic oil tank (314), and an accumulator; The photoelectric sensor (36) is disposed on the side of the rope winding drum (155) and is independent of the rotatable rope winding drum (155) to collect the positioning signal of the brake rope (12) exiting the rope; the angular displacement encoder (38) is disposed on the shaft end of the rope winding drum (155) and rotates together with the rotatable rope winding drum (155) to obtain the rotational displacement of the rope winding drum (155); the hydraulic oil tank (314) is connected to the hydraulic brake (141) through the hydraulic pump (313) to provide a hydraulic power source; a proportional valve group (312) for total pressure regulation and an accumulator for pressure holding are also provided on the pipeline between the hydraulic pump (313) and the hydraulic brake (141); the solenoid valve group (33) includes multiple solenoid valves, and each of the hydraulic brakes (141) and each of the electromagnetic clutches (171) is connected to one of the solenoid valves; The dual-redundant controller (31) is electrically connected to the photoelectric sensor (36) and the angular displacement encoder (38) respectively, and is used to use the position signal collected by the photoelectric sensor (36) or the rotational displacement obtained by the angular displacement encoder (38) as the braking criterion; the dual-redundant controller (31) is electrically connected to each solenoid valve in the solenoid valve group (33), and is used to hold the friction disc (154) for braking when the hydraulic brake (141) is pressurized, and to disconnect / connect the rope winding drum (155) from the reset drive when the electromagnetic clutch (171) is energized / de-energized; the dual-redundant controller (31) is also connected to the reset drive, and through the reset drive and the electromagnetic clutch (171) drive the rope winding drum (155) to flip and wind the rope, and pull the launch vehicle (2) to reset through the brake rope (12).

2. The control system for ejection braking of an unmanned aerial vehicle according to claim 1, characterized in that, The dual-redundant combination controller (31) mainly consists of two CPU controllers. The fiber optic communication interfaces of the two CPU controllers are interconnected through optical cables to perform redundant data communication.

3. A control system for ejection braking of an unmanned aerial vehicle according to claim 2, characterized in that, The optical fiber communication interface adopts a standard LC optical fiber interface with a communication rate of up to 1Gbps, ensuring that the link switching time of the dual-redundancy controller (31) does not exceed 10ms.

4. A control system for ejection braking of an unmanned aerial vehicle according to any one of claims 1-3, characterized in that, The control system also includes a radiator (32) for heat dissipation.

5. A control system for ejection braking of an unmanned aerial vehicle according to any one of claims 1-3, characterized in that, The reset drive adopts a servo drive mechanism, including a reset motor (173) and a reducer (172) connected to each other; the reset motor (173) is connected to the electromagnetic clutch (171) through the reducer (172).

6. A control system for ejection braking of an unmanned aerial vehicle according to any one of claims 1-3, characterized in that, When the electromagnetic valve connected to the electromagnetic clutch (171) is energized, the electromagnetic clutch (171) engages; when the electromagnetic valve connected to the electromagnetic clutch (171) is de-energized, the electromagnetic clutch (171) disengages; or, when the electromagnetic valve connected to the electromagnetic clutch (171) is de-energized, the electromagnetic clutch (171) engages; when the electromagnetic valve connected to the electromagnetic clutch (171) is energized, the electromagnetic clutch (171) disengages.

7. A control method for catapult braking of an unmanned aerial vehicle (UAV), characterized in that, The control system described in claim 1 uses a braking actuator to brake and reset the launch vehicle (2) that is slidably mounted on the power platform (1). Specifically, the control method first uses the position signal collected by the photoelectric sensor (36) or the rotational displacement obtained by the angular displacement encoder (38) as the braking criterion. Then, when the braking condition is met, the dual-redundant controller (31) controls the hydraulic brake (141) to pressurize through the solenoid valve connected to the hydraulic brake (141) to hold the friction disc (154) for braking. After braking is completed, the dual-redundant controller (31) controls the electromagnetic clutch (171) to operate through the solenoid valve connected to the electromagnetic clutch (171), so that the reset drive can engage with the rope winding drum (155). Then, the dual-redundant controller (31) sends a control command to the reset drive, and the reset drive drives the rope winding drum (155) to reverse and the retracted brake rope (12) to pull the launch vehicle (2) to reset.

8. A control method for ejection braking of an unmanned aerial vehicle according to claim 7, characterized in that, Before the launch vehicle (2) used for launching UAVs is started, the dual-redundant controller (31), solenoid valve group (33), proportional valve group (312), hydraulic pump (313), and accumulator are started. The dual-redundant controller (31) controls the operation of solenoid valve group (33), proportional valve group (312), hydraulic pump (313), and accumulator. On the one hand, the total pressure is adjusted to the predetermined pressure through proportional valve group (312) and the pressure is maintained by accumulator. On the other hand, the electromagnetic clutch (171) is controlled by solenoid valve group (33) to ensure that the rope winding drum (155) and the reset drive are disengaged.

9. A control method for ejection braking of an unmanned aerial vehicle according to claim 7, characterized in that, The rotational displacement obtained by the angular displacement encoder (38) installed at the shaft end of the rope winding drum (155) is used as the first-level braking criterion. If the angular displacement encoder (38) fails, the position signal collected by the photoelectric sensor (36) installed on the side of the rope winding drum (155) is used as the second-level braking criterion.

10. A control method for ejection braking of an unmanned aerial vehicle according to claim 7, characterized in that, When braking is performed using the aforementioned control system, the braking criteria are dynamically adjusted based on the braking response lag distance to perform lag compensation.

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