Device for air recovery of large spacecraft and control method

Abstract

The invention relates to the recycling problem of spacecrafts in the field of spaceflight, and discloses a device scheme capable of being installed on a helicopter or a fixed-wing aircraft to implement spacecraft air recycling and a control method. According to the device, the spacecraft is hooked in the air through the hook, winding and unwinding of the mooring rope are controlled through a whole set of system such as the controller, the servo motor, the speed reducer, the roller and the mooring rope hook, accurate hooking of the spacecraft in the air and stable mounting flight are achieved, and then lossless recycling of the spacecraft is achieved. The controller has the capacity of obtaining the positions of the spacecraft and the hook and providing guidance for the hooking process, and the controller further has the capacity of controlling the cable to be wound and unwound smoothly so as to guarantee recovery safety. In the recovery process, the instantaneous hooking impact is relieved through the buffer device in the equipment, and the tension of the cable is smoothed through the compliance control of the controller, so that the stability and reliability of the whole recovery process are ensured. The system comprises a locking device and a safety mechanism, so that the safety of the system can be further improved. The device is used for realizing in-air lossless recovery of recyclable spacecrafts and carrier rocket sub-stages, and is beneficial to safety of the recyclable spacecrafts and recycling of the carrier rocket sub-stages.

Description

Technical Field

[0001] The present invention relates to the field of aerial recovery of spacecraft, and in particular to a device and a control method for hooking a target in the air and implementing recovery. Background Art

[0002] Spacecraft that need to be recovered include recoverable satellites, spacecraft and rocket sub-stages. Recoverable satellites and spacecraft are generally recovered by parachute. They still have a certain speed when landing, which will produce a certain impact. However, recoverable satellites and spacecraft generally do not need to consider the issue of reuse, so the demand for lossless recovery is not urgent. However, lossless recovery in the air is of great significance to ensure the safety of the payload.

[0003] With the continuous development of the aerospace market, the requirements for controlling launch costs are getting higher and higher. In order to reduce launch costs, the reuse of launch vehicles has once again attracted attention. The premise of rapid reuse of rockets is to achieve lossless recovery. At present, the technology of full rocket reuse has not yet been realized, but there have been successful cases of recovery and reuse of the first stage of the rocket. The existing recovery methods mainly include parachute recovery, winged return, and vertical recovery. Parachute recovery is difficult to ensure the integrity and reusability of rocket stages; the winged return method has a large change in the aerodynamic shape of the rocket, and the structural efficiency is not high. This method has only been realized during the return of the space shuttle and is difficult to use for the recovery of existing rocket stages; vertical recovery is currently the most reliable method for recovering rocket stages, which has been realized by SpaceX, but this method has strict requirements on the control system and requires a certain amount of fuel to be reserved, which reduces the carrying efficiency of the rocket.

[0004] The air non-destructive recovery method is a new recovery method. This method can make full use of mature flight platforms and has many advantages. For the recovery of launch vehicles, it can effectively overcome the weakness of the vertical recovery of launch vehicle sub-stages; for the recovery of other large spacecraft, it can largely avoid the problem of spacecraft landing impact. The device described in the present invention is a core device for air non-destructive recovery.

[0005] When the speed of the recovered spacecraft is adjusted to a reasonable range, an airplane or helicopter carrying the device of the present invention is used to implement aerial hooking, thereby achieving non-destructive recovery of the spacecraft. When the spacecraft is large in size and mass (such as the first stage of a rocket), aerial recovery faces at least three challenges: first, it is difficult to achieve accurate hooking during the recovery process; second, a large impact force will be generated on the cable at the moment of hooking the spacecraft, which may damage the structure and affect flight safety; then, the speed change law of the cable tightening will cause changes in the cable tension, and abnormal cable tension will affect the safety of the recovered aircraft. The device and control method described in this patent can solve these three problems and achieve safe and non-destructive recovery in the air.

[0006] There are inventions and research papers that also aim to achieve the aerial recovery of rocket sub-stages. For example, Technology 1, "A device for helicopter recovery of rockets", has a core device consisting of a cable and a capture rod, and also includes an independent rocket recovery monitoring system. The cable length is fixed, the entire device does not consider the buffer function, the rocket recovery monitoring system is not related to the capture device, and the entire system does not have active control. Related Technology 2, "Design and Simulation Analysis of the Hanging Scheme of the Tail Cabin of a Launch Vehicle Based on Aerial Recovery (Zheng Zhenglu et al., Missile and Space Launch Technology (Chinese and English), 2024, No. 2)", introduces an aerial recovery main hanging device, which includes a tension sensor, an overload protection device, a load reduction device, a hook, and a cable connecting them in series. The system uses an overload protection device to avoid the impact of excessive abnormal loads on the flight safety of the aircraft, and uses a load reduction device to achieve buffering at the moment of hooking, but the cable length of the device is fixed, and it is impossible to achieve accurate hooking of the spacecraft and accurate control of the tension of the recovery cable through active control of the cable, and reliability and safety are difficult to guarantee. Summary of the invention

[0007] The present invention describes a recovery device that can be installed on a helicopter or fixed-wing aircraft and a control method based on cable tension and length feedback. The structure of the device is as follows: Figure 1 As shown. The purpose of the invention is to achieve non-destructive recovery of large spacecraft in the air while ensuring the safety of the recovered aircraft. The spacecraft to be recovered includes large-mass spacecraft such as launch vehicle sub-stages, returning spacecraft and recoverable satellites. Before using this device to recover the spacecraft, it is necessary to use a deceleration parachute to slow the spacecraft to a reasonable range, and then a helicopter or fixed-wing aircraft carrying this device will perform the recovery action.

[0008] This recovery device is a set of mechanical and electronic systems that realize two actions: hooking and recovery. In order to accurately hook the spacecraft to be recovered, it is necessary to know the position of the spacecraft and the position of the hook. The position of the spacecraft is obtained through the spacecraft position marker. The spacecraft position marker needs to be installed in advance at a suitable position on the spacecraft to be recovered and used in conjunction with the receiving device connected to the recovery device controller. When the spacecraft to be recovered enters a specific airspace, the position marker starts working and sends the position information of the spacecraft via radio. The receiving device connected to the controller receives the spacecraft position information and transmits it to the controller. The position of the hook can be obtained through the hook position marker, or it can be solved by measuring the angle and length of the cable. According to the position information of the two, navigation information is obtained to guide the flight of the aircraft and realize accurate hooking of the spacecraft.

[0009] The instantaneous impact during the hooking process can be alleviated by the buffer devices in the drum and the hook structure to avoid damage to the structure of the recovery system and the recovery aircraft.

[0010] When the spacecraft to be recovered is hooked, under the control of the controller, the servo motor drives the drum to rotate through the reducer, and the drum twists the cable to achieve the retraction and release of the spacecraft. During the recovery process, the controller controls the retraction and release of the cable according to the torque feedback from the torque sensor and the length of the cable according to a specific control law, achieving smooth control, so that the tension on the cable changes smoothly and is limited to a reasonable range to ensure the safety of the aircraft during the recovery process. When the controller is sensitive to abnormal cable tension and affects the flight safety of the aircraft, an alarm is issued to remind the operator to operate the insurance mechanism and abandon the spacecraft to ensure the safety of the aircraft and personnel.

[0011] The advantages of the invention are:

[0012] This device is suitable for large spacecraft aerial recovery operations;

[0013] The controller has the function of receiving a variety of feedback information. The controller's smooth control ensures that the spacecraft is subjected to stable force during the recovery process, making the recovery flight safer.

[0014] The controller has the ability to sense the position of the spacecraft to be recovered and the hook position, and provide guidance for accurately hooking the spacecraft;

[0015] The system is equipped with locking devices and insurance mechanisms to improve the safety of the recycling process;

[0016] The impact when hooking the spacecraft is mitigated by a buffer device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is the composition of the recovery device system; in the figure, 1 is the insurance mechanism, 2 is the roller support, 3 is the roller, 4 is the buffer device, 5 is the hook, 6 is the locking device, 7 is the reducer, 8 is the torque sensor, 9 is the servo motor, 10 is the controller, 11 is the position marker information receiver, and 12 is the position marker of the spacecraft to be recovered;

[0018] Figure 2 Schematic diagram of a hook and a buffer device; 51 is a hook position marker, and 52 is a hook buffer device. DETAILED DESCRIPTION

[0019] One of the specific implementation methods is Figure 1 The specific work of each part is described as follows:

[0020] The hook 5 is connected to the cable, the cable is wound on the drum 3, and the other end of the cable is fixed by a clamping device, which can be manually controlled by the locking device 1. Under the control of the controller 10, the drum 3 is driven to rotate by the motor 9 and the reducer 7 to realize the retraction and release of the cable.

[0021] Specifically, the controller 10 adjusts the retraction and extension of the cable according to the feedback value of the torque sensor 8 and the length of the cable, so that the tension of the cable is smooth and within a reasonable range, so as to ensure the flight safety of the recovery aircraft during the recovery process;

[0022] The controller 10 obtains the information of the spacecraft's position marker 12 and the position information of the hook or calculates the position of the hook, and displays their positions on the screen to guide the flight of the recovery aircraft and realize the aerial hooking of the spacecraft to be recovered. The controller 10 receives the position information sent by the position marker on the spacecraft through the wireless receiving device 11; the controller can obtain the position of the hook by installing a hook position marker on the hook (see Figure 2 Component 51) can also be calculated using the length and angle of the cable.

[0023] The controller 10 has the function of sensitively recovering the position and attitude of the aircraft or has a reserved interface for receiving the position and attitude information of the aircraft.

[0024] The locking device 6 is a manual device with an operating handle. When the cable for mounting and recovering the spacecraft is retracted to a suitable length, the locking handle is pulled down to lock the roller 3 to ensure the safe transportation of the spacecraft.

[0025] The roller support 2 is used to support the roller and is the main load-bearing component of the system.

[0026] The safety mechanism 1 is a manual device for handling special situations. When encountering recovery anomalies and the spacecraft to be recovered has a fatal impact on the safety of the recovery aircraft, the operator manually abandons the recovered spacecraft according to the alarm issued by the controller to ensure the safety of the aircraft and personnel. When in a dangerous scene, the operator pulls down the handle of the safety mechanism, and the safety mechanism 1 releases the cable clamping mechanism (not shown in the figure) through the linkage mechanism, releasing the cable and the hooked load to ensure the safety of the recovery aircraft.

[0027] The buffer device is a mechanical structure device, which can be installed in at least two places: between the roller and the shaft (such as Figure 1 4), on the hook handle (see Figure 2 52 in FIG. 1 ). According to the weight level of the system to be recovered, a buffer device can be installed at one or two locations. The function of the device is to act as a buffer at the moment of hooking the spacecraft to be recovered, so as to avoid excessive impact that harms the structure of the recovery system and the flight safety of the spacecraft.

[0028] The servo motor 9, the reducer 7 and the torque sensor 8 are standard industrial components, and the connection of the torque sensor signal is realized by a slip ring. The position marker 12 and its signal transmission and receiving device 11 can be realized by using existing mature technology.

[0029] Figure 2Only two barbs are drawn on the middle hook for illustration only. In practice, three or four barbs are preferred. The connection between the barbs and the hook body can be fixed or a retractable hinge mechanism containing elastic elements.

[0030] The hook marker is used to identify the position of the hook during spacecraft recovery, but it is an optional device and can be omitted when the hook position is calculated by the cable angle and length.

[0031] Figure 1 The torque sensor 8 can be installed at other feasible places, such as between the reducer and the roller.

[0032] Figure 1 The servo motor and reducer may also be replaced by a servo motor reducer assembly or other components with equivalent functions.

[0033] Figure 1 The coaxial arrangement of the middle drum and the motor reducer is only one of the implementation methods. The drum shaft and the motor reducer shaft can also be arranged in parallel through a transmission mechanism.

[0034] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A device for recovering large spacecraft in mid-air, characterized in that: include: Safety mechanism, roller support, roller, buffer device, cable and hook, locking device, reducer, torque sensor, servo motor, controller, position marker information receiver and position marker of the spacecraft to be recovered.

2. The device for recovering a large spacecraft in mid-air according to claim 1, characterized in that: The recovery system includes a buffer device, which is installed on the roller and the hook to cushion the impact force at the moment of hooking, thereby ensuring the structural safety of the recovery system and the flight safety of the aircraft.

3. The device for recovering a large spacecraft in mid-air according to claim 1, characterized in that: One end of the cable is fixed to the side wall of the drum through a clamping mechanism, and the clamping mechanism can be unlocked by a safety mechanism.

4. The device for recovering a large spacecraft in mid-air according to claim 1, characterized in that: The recovery system includes a safety mechanism that has the function of loosening the cable clamping mechanism and releasing the cable. When the recovery mission is abnormal and threatens flight safety, the recovered spacecraft can be abandoned by manually operating the safety mechanism to ensure the safety of the recovery aircraft and personnel.

5. The device for recovering a large spacecraft in mid-air according to claim 1, characterized in that: The recovery system includes a locking device, which can lock the roller by manually operating the locking device to ensure the safety and reliability of the mounting flight process.

6. A control method for a large spacecraft air recovery device, characterized in that: include: Control the rotation of the servo motor in the recovery device, display the position of the spacecraft and the position of the hook, sense the position and attitude of the aircraft, input the position and attitude of the aircraft through the electrical interface, receive the position information of the spacecraft and the hook, and calculate the hook position according to the cable length and angle.

7. A control method for a large spacecraft air recovery device according to claim 6, characterized in that: The controller automatically adjusts the retraction and extension of the cable according to the spacecraft and hook position to achieve precise hooking.

8. A control method for a large spacecraft air recovery device according to claim 6, characterized in that: The compliant control strategy based on torque feedback and cable length ensures that the cable tension changes smoothly during the recovery process, effectively ensuring the flight safety of the aircraft.

9. A control method for a large spacecraft aerial recovery device according to claim 6, characterized in that: By obtaining the information of the position marker and the position of the hook of the spacecraft to be recovered, and displaying their positions on the screen, it is used to guide the flight of the recovery vehicle and achieve reliable hooking of the spacecraft.

10. A control method for a large spacecraft air recovery device according to claim 6, characterized in that: The controller uses the sensitive or received aircraft position and attitude information to calculate the absolute position of the hook.

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