A kind of anti-collision device for rotor unmanned aerial vehicle flight

Abstract

The application belongs to the field of unmanned aerial vehicle, and provides a rotor unmanned aerial vehicle flight anti-collision device, which comprises a buffer system and a multi-mode redundant sensing trigger module, the buffer system is electrically connected with the multi-mode redundant sensing trigger module, the multi-mode redundant sensing trigger module is used for detecting obstacles and triggering the buffer system to expand, and the buffer system is used for absorbing impact energy and protecting the unmanned aerial vehicle body; the buffer system comprises four buffer assemblies and four anti-collision cages; the four buffer assemblies are respectively installed on four supporting arms of the unmanned aerial vehicle body. In the application, the buffer assemblies and the elastic supporting mechanism are in the initial state of folding and folding, the external protective film adopts a streamline design, and the wind resistance coefficient is reduced by 40% compared with the traditional rigid cover; the buffer system adopts lightweight materials such as nickel-titanium super-elastic memory alloy wire and ultra-high molecular weight polyethylene fiber, effectively reduces the overall weight of the device, reduces the flight energy consumption, and greatly improves the flight performance and endurance of the unmanned aerial vehicle.

Description

Technical Field

[0001] This invention belongs to the field of unmanned aerial vehicles (UAVs), and particularly relates to a collision avoidance device for rotorcraft UAVs. Background Technology

[0002] With the rapid development of drone technology, rotary-wing drones have been widely used in various fields such as aerial surveying and mapping, power line inspection, agricultural plant protection, and emergency rescue. However, in actual flight, drones often face complex flight environments, such as low-altitude obstacles, sudden moving objects, and severe weather (rain, fog, sandstorms), which can easily lead to collision accidents, resulting in damage to the drone fuselage and rotors, and even serious consequences such as crashes and equipment loss, causing economic losses.

[0003] Currently, most existing drone collision avoidance technologies are passive collision avoidance technologies. These technologies rely on rigid protective frames, buffer pads, and other structures on the drone's fuselage or arms to absorb impact energy through structural deformation. However, these technologies suffer from drawbacks such as high wind resistance and heavy weight, which can seriously affect the drone's flight performance and endurance. Furthermore, their buffering effect is limited, making it difficult to cope with high-speed collisions and impacts from small obstacles.

[0004] Therefore, developing a collision avoidance device for rotary-wing drones that combines low wind resistance, high response, strong buffering, and high reliability has become a key requirement for solving current technical pain points. Summary of the Invention

[0005] The purpose of this invention is to provide a collision avoidance device for rotorcraft drones, aiming to solve the technical problems of high wind resistance and heavy weight in existing collision avoidance devices using rigid protective frames, buffer pads, and other structures.

[0006] The present invention is implemented as follows: a collision avoidance device for rotorcraft drones includes a buffer system and a multi-mode redundancy sensing trigger module. The buffer system is electrically connected to the multi-mode redundancy sensing trigger module. The multi-mode redundancy sensing trigger module is used to detect obstacles and trigger the deployment of the buffer system. The buffer system is used to absorb impact energy and protect the drone body.

[0007] The drone body is equipped with four arms, which are symmetrically distributed, and each of the four arms has a rotor at its end.

[0008] The buffer system includes four buffer components and four anti-collision cages;

[0009] The four buffer components are respectively installed on the four support arms. The axes of the four buffer components are all coincident. They are folded in the initial state and unfold to form a ring-shaped protective structure after being triggered.

[0010] The buffer assembly includes two arc-shaped frames, both of which are detachably mounted on the support arm via a clamping plate. The two arc-shaped frames are symmetrically distributed on both sides of the support arm. Each arc-shaped frame has a groove at both ends, and a folding buffer wing is movably installed in the groove.

[0011] The folding buffer wing has a rectangular structure, consisting of an internal skeleton and an external protective film. The skeleton is a diamond-shaped mesh structure woven from φ0.5mm nickel-titanium superelastic shape memory alloy wires. Multiple diamond-shaped mesh structures are arranged in parallel and evenly. The ends of the diamond-shaped mesh alloy wires are electrically connected to the multi-mode redundancy sensing trigger module via wires. The external protective film is woven and covered with ultra-high molecular weight polyethylene fiber, with a streamlined surface. Initially, the folding buffer wing is folded in a fan-shaped state and stored in the groove of the arc-shaped frame. When the multi-mode redundancy sensing trigger module detects a collision risk, it energizes the diamond-shaped mesh alloy wires. Utilizing the stress-induced martensitic phase transformation characteristics of the nickel-titanium superelastic shape memory alloy wires, the folding buffer wing unfolds rapidly. The folding buffer wings of the four buffer components work together to form a complete protective ring, providing comprehensive protection for the main body of the UAV.

[0012] The four anti-collision cages are semi-enclosed hollow structures, respectively installed at the ends of the four support arms. The anti-collision cages completely surround the rotor inside, which is used to protect the rotor individually and prevent the rotor from directly colliding with obstacles.

[0013] Further technical solution: The buffer system also includes four elastic support mechanisms, which are respectively installed around the main body of the UAV and correspond to the junctions of the four buffer components. They are used to provide elastic support for the unfolded folding buffer wings, thereby improving the deformation resistance and buffering effect of the buffer components.

[0014] The elastic support mechanism includes a mounting frame, a mounting plate, and a foldable support assembly. The mounting plate is fixedly mounted on the fuselage of the UAV body by bolts. The mounting frame is fixedly connected above the mounting plate. The foldable support assembly is installed inside the mounting frame and includes two sliders, two support rods, two memory alloy springs, two telescopic support assemblies, and a support block.

[0015] Both sliders are slidably installed inside the mounting frame, and the two sliders are arranged opposite each other. The two support rods are rotatably installed on opposite sides of the two sliders. A torsion spring connects the sliders and the support rods. Initially, the support rods retract into the mounting frame. The two support rods are rotatably connected to a support block through a pin, and the pin is fixedly connected to the support rods.

[0016] Two memory alloy springs are respectively installed on the opposite sides of the two sliders. The memory alloy springs are made of nickel-titanium superelastic memory alloy wire. One end of each memory alloy spring is fixedly connected to the inner wall of the mounting frame, and the other end abuts against the two sliders respectively. Both ends of the memory alloy springs are electrically connected to the multi-mode redundancy sensing trigger module through wires. Initially, the memory alloy springs are in a compressed state. When the multi-mode redundancy sensing trigger module is triggered, the memory alloy springs are energized. The memory alloy springs are heated and stretch from the compressed state, pushing the two sliders to move towards each other. This, in turn, causes the support rod to unfold, pushing the support block away from the mounting frame, so that the support block is in close contact with the side of the folding buffer wing, achieving elastic support for the folding buffer wing. After the impact, the memory alloy springs are de-energized and automatically return to the compressed state. Under the action of the torsion spring, the two sliders move away from each other, the support rod retracts, and the support block adheres to the mounting frame, reducing flight drag.

[0017] Further technical solution: The elastic support mechanism also includes two retractable support components, which are symmetrically distributed about the central axis of the support block to adapt to the width of the folding buffer wing and improve the support stability without increasing wind resistance;

[0018] The retractable support assembly includes a support column, a piston column, a piston plate, a compression spring, and a pressure box. The support block has a storage groove and an air chamber, which are connected to each other through a connecting air hole. The piston column is slidably installed in the storage groove. The support column is fixedly connected to the end of the piston column and extends from the end of the storage groove away from the air chamber. The piston plate is slidably installed in the air chamber. The compression spring is connected between the piston plate and the inner side wall of the air chamber away from the storage groove. The pressure box is fixedly connected to the side of the piston plate away from the storage groove, and one end of the pressure box extends out of the air chamber. A cam is fixedly connected to the side of the pin, and the cam contacts the side of the pressure box.

[0019] When the support rod unfolds, the pin drives the cam to rotate. The cam squeezes the pressure box and pushes the piston plate into the air chamber. The air in the air chamber enters the storage slot through the connecting air hole, pushing the piston column and the support column to extend, thus supporting the upper and lower ends of the folding buffer wing. After the impact, the cam disengages from the pressure box. Under the action of the compression spring, the piston plate returns to its original position, drawing the air in the storage slot back into the air chamber. The support column retracts into the storage slot under atmospheric pressure.

[0020] Further technical solution: The multi-mode redundant perception triggering module, as the core of the collision avoidance system, is used to realize 360° blind-spot-free detection of obstacles, collision risk prediction, and precise triggering of the buffer system, including hardware modules and software modules;

[0021] The hardware module consists of three types of heterogeneous sensors: a millimeter-wave radar unit, an infrared TOF+polarization vision unit, and an ultrasonic array unit, as well as a data processing and control unit. It is deployed in a "far-medium-near" gradient to cover the entire airspace of 360° horizontally and ±45° vertically, achieving no detection blind spots.

[0022] Further technical solutions: Long-range main detection unit: It adopts four groups of 77GHz 4D millimeter-wave radars, symmetrically embedded in the four corners of the UAV fuselage. Each group covers a 90° horizontal field of view and ±45° vertical field of view. The four groups are seamlessly stitched together to form an omnidirectional detection network. Its main functions are long-range early warning (1.5~30m), dynamic tracking of obstacle speed and trajectory, prediction of collision time (TTC), and serving as the main reliable data source in adverse weather conditions.

[0023] Mid-range blind spot filling unit: It adopts 8 sets of infrared TOF + polarized light cameras, one set on each arm and one on the top and bottom, corresponding to the rotor gap and fuselage blind spot. The lens is coated with nano anti-reflection film and has anti-glare function. Its main function is to accurately fill blind spots at mid-range (0.3~1.5m), solve the problem of blurred outline of small obstacles (power lines, fishing lines, tree branches) by millimeter wave radar, identify transparent targets, and make up for radar blind spots;

[0024] Near-field auxiliary unit: It adopts 4 groups of 16-channel ultrasonic arrays, which are respectively deployed at the bottom of the fuselage and the four corners. Each group has 4 channels and uses beamforming directional transmission. Its main function is near-field micro-gap detection (0.05~0.3m), which is specifically designed to capture "invisible obstacles" such as wires and twigs, and achieve redundancy and blind spot filling in low-altitude and indoor environments.

[0025] Further technical solution: The software module adopts AI-integrated voting triggering logic, including a three-level data fusion mechanism and a redundancy fault tolerance mechanism, to achieve millisecond-level closed-loop triggering control;

[0026] 1. Three-level data fusion mechanism (layered filtering + redundancy verification):

[0027] 1) Data layer fusion (bottom layer): Achieve 1μs-level hard synchronization of all sensors to eliminate time deviation; perform validity verification on sensor data and remove outliers such as those exceeding the physical range, signal loss, and noise mutations; and convert all sensor data into the fuselage coordinate system to build a 360° real-time point cloud map.

[0028] 2) Feature layer fusion (middle layer): Improved extended Kalman filter (EKF) is used to fuse multi-source data to accurately estimate the true position, velocity and acceleration of obstacles; sensor weights are dynamically allocated according to the flight environment (rainy weather: radar weight 80%; sunny weather: visual unit weight 60%; close range: ultrasonic array weight 70%); when multi-sensor data are inconsistent, a two-out-of-three voting mechanism is used to ensure data validity.

[0029] 3) Decision-making level integration (top level): Pre-set collision risk model, define risk coefficient R; set three-level trigger thresholds:

[0030] Early warning (R1): When the distance to the obstacle is d=1.5~3m, the flight control system performs pre-deceleration, and the buffer components and elastic support mechanism are pre-energized and ready to go;

[0031] Warning (R2): When the distance to the obstacle is d = 0.3~1.5m, the system enters the standby state;

[0032] Emergency Trigger (R3): When the distance to the obstacle d≤0.3m, the buffer component and elastic support mechanism are immediately triggered, and the timing of triggering the buffer component is 10ms~15ms earlier than the timing of triggering the elastic support mechanism, to ensure that the elastic support mechanism can support the unfolded folding buffer wing in time.

[0033] 2. Redundancy and fault tolerance mechanism (fault isolation + seamless switching): Real-time monitoring of the heartbeat, signal strength and data continuity of all sensors, with fault identification time ≤5ms;

[0034] When a single sensor fails, the faulty sensor is automatically isolated, and the remaining sensors take over the detection and triggering functions without affecting the normal operation of the overall collision avoidance function (for example, when the vision unit fails, the millimeter-wave radar and ultrasonic array work together; when the radar unit fails, the infrared TOF, polarization vision unit and ultrasonic array work together).

[0035] Further technical solution: The workflow of the multi-mode redundancy sensing trigger module is a millisecond-level closed loop, specifically including five stages:

[0036] Phase 1: Normal cruise (no risk); all three types of sensors operate at full power, scanning at 500Hz high frequency; the data processing and control unit outputs an environmental map, with a risk factor R≈0; the buffer system is in a retracted state, minimizing wind resistance;

[0037] Phase 2: Early warning (d=1.5~3m, R=R1); the millimeter-wave radar or vision unit detects the obstacle and predicts the collision time TTC≤1s; the flight control executes pre-deceleration; the buffer components and elastic support mechanism of the buffer system increase the power supply current and enter the preheating standby state, shortening the response time to 3ms;

[0038] Phase 3: Warning (d=0.3~1.5m, R=R2); At least two types of sensors confirm the presence of the obstacle, and the collision time TTC≤0.3s; The data processing and control unit outputs a high-confidence trigger command; The buffer system enters the ready-to-trigger state and can be deployed immediately within 10ms;

[0039] Phase 4: Emergency Trigger (d≤0.3m); when the condition of simultaneous confirmation of obstacles by three types of sensors is met, the trigger command is output with zero delay (command transmission time≤100μs); the folding buffer wing and support column are fully deployed with a deployment time≤12ms, and the protective ring adaptively deflects to absorb impact energy;

[0040] Phase 5: Post-collision reset; after the impact ends, the sensors detect no obstacles and the risk factor is cleared to zero; the buffer components and elastic support mechanism are powered off, and the folding buffer wings and support columns automatically retract and reset; the system performs a self-check, and after the self-check passes, the drone resumes normal flight.

[0041] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0042] 1. Comprehensive detection, rapid response, and high reliability: Employing a multi-mode redundant perception trigger module, it utilizes a three-level perception redundancy design of "long-range pre-detection - mid-range blind spot filling - close-range access," combined with the collaborative work of three types of heterogeneous sensors, to achieve 360° blind-spot-free, all-weather detection. This effectively addresses four major pain points: single sensor failure, misjudgment in harsh environments, missed detection of minute / transparent obstacles, and lag in high-speed collision response. AI-integrated voting trigger logic and redundancy fault-tolerance mechanism ensure the accuracy and reliability of trigger commands. Even if a single sensor fails, the collision avoidance function can still operate normally, with a millisecond-level closed-loop response (deployment time ≤12ms), effectively addressing the risk of sudden collisions.

[0043] 2. Excellent buffering effect and comprehensive protection: The buffering system adopts a diamond-shaped mesh skeleton woven from nickel-titanium superelastic shape memory alloy wire, combined with an ultra-high molecular weight polyethylene fiber protective film. The impact energy absorption efficiency is ≥85%, and the tensile strength is high, which can realize rapid recovery after large deformation collision and effectively absorb impact energy. When the four buffer components are deployed, they form a complete protective ring. Combined with the double buffering effect of four elastic support mechanisms, it can achieve comprehensive protection for the main body of the UAV. At the same time, the semi-enclosed hollow structure anti-collision cage protects the rotor separately to avoid direct collision damage to the rotor, further improving the comprehensiveness of protection.

[0044] 3. Low drag and lightweight design enhance flight performance and endurance: The buffer components and elastic support mechanism are initially folded and stowed, and the external protective film adopts a streamlined design, reducing the drag coefficient by 40% compared to traditional rigid covers; the buffer system uses lightweight materials such as nickel-titanium superelastic shape memory alloy wire and ultra-high molecular weight polyethylene fiber, effectively reducing the overall weight of the device and reducing flight energy consumption, thereby greatly improving the flight performance and endurance of the UAV.

[0045] 4. Reasonable structure, retractable and adaptable, highly practical: The retractable support component in the elastic support mechanism achieves automatic extension and retraction of the support column through the coordinated action of the cam, pressure box, and piston structure. It can adapt to the width of the folding buffer wing, providing stable support, and reduce wind resistance when folded, thus solving the technical contradiction between "wide buffer wings require tall support blocks" and "tall support blocks increase wind resistance". The buffer component adopts a detachable clamp installation, which is convenient for maintenance and replacement, and is compatible with different models of multi-rotor UAVs, making it highly practical.

[0046] 5. Automatic reset and reusable: After a collision, the buffer components and elastic support mechanism can be automatically powered off and reset. The folding buffer wings and support columns can be quickly retracted. After the system self-checks, it can immediately resume normal flight without manual intervention. It can be reused, reducing operating costs. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0048] Figure 2 This is a schematic diagram of the cross-sectional structure of the buffer component in this invention.

[0049] Figure 3 This is a schematic diagram of the elastic support mechanism in this invention.

[0050] Figure 4 This is a schematic diagram of a partial cross-sectional structure of the elastic support mechanism in this invention.

[0051] In the attached diagram: 1. UAV body; 2. Support arm; 3. Rotor; 4. Collision cage; 5. Buffer assembly; 51. Arc frame; 52. Clamping plate; 53. Folding buffer wing; 6. Elastic support mechanism; 61. Mounting frame; 62. Foldable support assembly; 621. Slider; 622. Support rod; 623. Support block; 624. Air chamber; 625. Connecting air hole; 626. Cam; 627. Pressure box; 628. Piston column; 629. Piston plate; 6210. Compression spring; 6211. Storage slot; 6212. Pin; 6213. Support stop; 6214. Memory alloy spring; 63. Mounting plate. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0053] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0054] like Figures 1-4As shown, this invention provides a collision avoidance device for rotorcraft drones, including a buffer system and a multi-mode redundant sensing trigger module. The buffer system includes four buffer components 5 and four collision cages 4. The four buffer components 5 are all installed on the drone body 1. The drone body 1 is provided with four support arms 2, which are arranged in a cross-shaped symmetrical distribution. The ends of the four support arms 2 are all equipped with rotors 3 via motors. The four buffer components 5 are respectively installed on the four support arms 2, and the axes of the four buffer components 5 are all coincident.

[0055] The buffer assembly 5 includes two arc-shaped frames 51, both of which are mounted on the support arm 2 via a clamping plate 52. Each arc-shaped frame 51 has slots at both ends, and folding buffer wings 53 are installed within these slots. The folding buffer wings 53 are cuboid structures, consisting of an internal frame and an external protective film. The frame is made of φ0.5mm material. A diamond-shaped mesh structure woven from nickel-titanium superelastic shape memory alloy wires is constructed, with multiple wires evenly arranged in parallel. The ends of these wires are electrically connected to a multi-mode redundant sensing trigger module via wires. Initially, the folding buffer wing 53 is in a fan-shaped folded state. When the multi-mode redundant sensing trigger module detects that the UAV body 1 is about to collide with an object, it energizes the diamond-shaped mesh wires through two wires. Resistance heat is generated, and utilizing the stress-induced martensitic phase transformation characteristics of the nickel-titanium wires, the folding buffer wing 53 rapidly unfolds. This causes the four buffer components 5 to form a protective ring, protecting the main body of the UAV body 1. The nickel-titanium superelastic shape memory alloy wires have a tensile strength of 850-1400 MPa and an impact energy absorption efficiency ≥85%. After a large deformation collision, they can automatically reset within 1 second, causing the folding buffer wing 53 to automatically fold and retract into the arc-shaped frame 51. The nickel-titanium superelastic shape memory alloy wires exhibit no permanent plastic deformation and can cyclically buffer over 1000 times. Secondly, the outer protective film is made of ultra-high molecular weight polyethylene fiber woven covering, which is wear-resistant and scratch-resistant, with a smooth and streamlined surface, and the wind resistance coefficient is reduced by 40% compared with traditional rigid covers;

[0056] The four anti-collision cages 4 are semi-enclosed hollow structures made of lightweight aluminum alloy. They are installed at the ends of the four support arms 2 respectively. The anti-collision cages 4 completely surround the rotor 3 inside them to protect the rotor 3 individually and prevent the rotor 3 from colliding directly with obstacles. At the same time, the hollow structure can reduce wind resistance.

[0057] This invention uses lightweight materials such as nickel-titanium superelastic shape memory alloy wire and ultra-high molecular weight polyethylene fiber, and the buffer system is folded before the impact, which reduces wind resistance and thus greatly improves the performance and endurance of the drone.

[0058] The buffer system also includes four elastic support mechanisms 6, which are installed around the main body of the UAV 1. The elastic support mechanisms 6 are used to provide elastic support for the unfolded folding buffer wings 53 so that the folding buffer wings 53 can better protect the UAV 1.

[0059] The elastic support mechanism 6 includes a mounting frame 61 and a mounting plate 63. The mounting frame 61 is connected above the mounting plate 63. The mounting plate 63 is bolted to the fuselage of the UAV body 1. A foldable support assembly 62 is installed inside the mounting frame 61. The foldable support assembly 62 includes two sliders 621. Both sliders 621 are slidably installed inside the mounting frame 61. Support rods 622 are rotatably installed on opposite sides of the two sliders 621. A torsion spring is connected between the sliders 621 and the support rods 622. Initially, the support rods 622 retract into the mounting frame 61. Both support rods 622 are rotatably connected to support blocks 623 through pins 6212. The pins 6212 are fixedly connected to the support rods 622.

[0060] The foldable support assembly 62 also includes two shape memory alloy springs 6214. The two shape memory alloy springs 6214 are respectively mounted on opposite sides of the two sliders 621. One end of each shape memory alloy spring 6214 is connected to the mounting frame 61, and the other end of each shape memory alloy spring 6214 abuts against the two sliders 621. Both ends of each shape memory alloy spring 6214 are electrically connected to the multi-mode redundancy sensing trigger module via wires. The shape memory alloy springs 6214 are made of nickel-titanium superelastic shape memory alloy wire. Initially, the shape memory alloy springs 6214 are in a compressed state. When the multi-mode redundancy sensing trigger module supplies power to the shape memory alloy springs 6214, current flows through the shape memory alloy springs 6214, causing the shape memory alloy springs 6214 to compress. Heat is generated, and the shape memory alloy spring 6214 extends from the compressed state, providing a pushing force to the slider 621, causing the two sliders 621 to move towards each other. This pushes the support block 623 away from the mounting frame 61 and makes the support block 623 contact the side of the folding buffer wing 53 to provide elastic support for the folding buffer wing 53. When the folding buffer wing 53 contacts the impacting object, the folding buffer wing 53 performs the first buffering, and then the support block 623 performs the second buffering. The shape memory alloy spring 6214 provides the buffering force. After the impact, the shape memory alloy spring 6214 is de-energized and automatically returns to the compressed state. Under the action of the torsion spring, the two sliders 621 move away again, causing the support block 623 to stick to the mounting frame 61, reducing the resistance of the elastic support mechanism 6.

[0061] To protect the entire fuselage of the drone body 1, the width of the folding buffer wing 53 needs to be large enough. To better support the folding buffer wing 53, the height of the support block 623 needs to be compatible with the width of the folding buffer wing 53. However, a taller support block 623 would significantly increase wind resistance, affecting the flight performance of the drone body 1. Therefore, the foldable support assembly 62 also includes two retractable support assemblies. Each retractable support assembly includes a support column 6213, a piston column 628, and a piston plate 629. The support block 623 has a storage slot 6211 and an air chamber 624. The piston column 628 is slidably mounted on the storage slot 621. Inside 1, the support column 6213 is fixedly connected to the end of the piston column 628. The support column 6213 extends from one end of the receiving groove 6211. The piston plate 629 is slidably installed in the air chamber 624. A compression spring 6210 is connected between the piston plate 629 and the air chamber 624. The air chamber 624 is connected to the end of the receiving groove 6211 through a connecting air hole 625. A pressure box 627 is fixedly connected to the side of the piston plate 629 away from the receiving groove 6211. One end of the pressure box 627 extends out of the air chamber 624. A cam 626 is fixedly connected to the side of the pin 6212. The cam 626 contacts the side of the pressure box 627.

[0062] Specifically, the two retractable support components are symmetrically distributed about the central axis of the support block 623, so that the two support posts 6213 extend from the upper and lower end faces of the support block 623 respectively to support the folding buffer wing 53.

[0063] In use, the shape memory alloy spring 6214 pushes the two sliders 621 closer together, causing the two support rods 622 to drive the pin 6212 to rotate. The pin 6212 compresses the pressure box 627 through the cam 626, squeezing the pressure box 627 and the piston plate 629 into the air chamber 624. The air in the air chamber 624 enters the storage slot 6211 through the connecting air hole 625 and pushes the support column 6213 to extend, thus supporting the folding buffer wing 53. When restoring, the two support rods 622 unfold again, and the support rods 622 drive the cam 626 to move away from the side of the pressure box 627. Under the action of the compression spring 6210, the piston plate 629 moves away from the inner wall of the air chamber 624, thereby drawing the air in the storage slot 6211 back into the air chamber 624. Under the action of atmospheric pressure, the support column 6213 retracts back into the storage slot 6211.

[0064] The multi-mode redundant perception trigger module is the "nerve ending + decision center" of the collision avoidance system. It solves four major pain points: single sensor failure, misjudgment in harsh environments, missed detection of small / transparent obstacles, and lag in high-speed collision response. Through a three-level perception redundancy of "long-range pre-detection - mid-range blind spot filling - close-range arrival" + AI fusion voting trigger logic, it achieves 360° blind-spot-free, all-weather, millisecond-level collision avoidance triggering, which is the core guarantee for the safety and reliability of the entire system.

[0065] The multi-mode redundancy sensing trigger module includes hardware and software modules;

[0066] Hardware module: Three types of sensors deployed omnidirectionally (without blind spots or redundancy)

[0067] The hardware module consists of three types of heterogeneous sensors: a millimeter-wave radar unit, an infrared TOF+polarization vision unit, and an ultrasonic array unit, as well as a data processing and control unit. It is deployed in a "far-medium-near" gradient, covering the entire airspace of 360° horizontally and ±45° vertically, with no detection blind spots.

[0068] 1. Long-range main detection unit: 77GHz 4D millimeter-wave radar (4 groups)

[0069] Deployment: The four groups are symmetrically embedded at the front, rear, left and right corners of the fuselage, each covering a 90° horizontal field of view and a ±45° vertical field of view. The four groups are seamlessly spliced ​​together to form an omnidirectional detection network.

[0070] Core parameters:

[0071] Frequency band: 77GHz (industrial grade, resistant to rain, fog, dust, and backlight interference);

[0072] Detection distance: 0.2~30m, ranging accuracy ±3cm, speed accuracy ±0.1m / s;

[0073] Output: obstacle distance, relative velocity, azimuth angle, pitch angle, and outline point cloud;

[0074] Refresh rate: 50Hz (20ms / frame), can penetrate plastic, thin wood, rain and fog;

[0075] Functions: Long-range early warning (1.5-30m), dynamic tracking of obstacle speed / trajectory, prediction of collision time (TTC), and serving as a primary and reliable data source in severe weather (rain / snow / fog / dust).

[0076] 2. Mid-range blind spot compensation unit: Infrared TOF + polarized light camera (8 sets, accurate ranging)

[0077] Layout: There are 1 set on each of the upper and lower arms 2 (8 sets in total), corresponding to the gap of rotor 3 and the blind spot of the fuselage. The lens is attached with a nano-anti-reflective coating to prevent glare.

[0078] Core parameters:

[0079] Infrared TOF: 850nm infrared invisible light, detection distance 0.1~10m, accuracy ±1cm, works normally in low light / night;

[0080] Polarized light camera: 4-channel polarized imaging to identify targets that traditional visual detection methods miss, such as glass, transparent plastic, and water surfaces;

[0081] Blending output: obstacle depth map, outline, material properties (transparent / non-transparent);

[0082] Refresh rate: 100Hz (10ms / frame);

[0083] Function: Mid-range precision blind spot filling (0.3~1.5m), solving the problem of blurred outlines of small obstacles (power lines, fishing lines, tree branches) by millimeter waves, identifying transparent targets, and compensating for radar blind spots.

[0084] 3. Close-range auxiliary unit: 16-channel ultrasound array (4 groups, extremely close-range anti-collision)

[0085] Deployment: One set at the bottom of the fuselage and one at each of the four corners, with four channels in each set, using beamforming for directional transmission.

[0086] Core parameters:

[0087] Detection distance: 0.05~5m, accuracy ±5mm, response time ≤1ms;

[0088] Features: Extremely high sensitivity to very fine wires (φ0.1~2mm) and high sound-absorbing materials;

[0089] Refresh rate: 200Hz (5ms / frame);

[0090] Function: Close-range micro-gap detection (0.05~0.3m), specifically designed to detect "invisible obstacles" such as wires and twigs, providing redundancy and blind spot compensation in low-altitude / indoor environments.

[0091] Software module: AI-integrated voting trigger logic

[0092] 1. Three-level data fusion mechanism (layered filtering + redundancy check)

[0093] 1) Data layer fusion (bottom layer)

[0094] Timestamp synchronization: All sensors are hard synchronized (1μs level), eliminating time deviation;

[0095] Validity verification: Remove outliers (outside physical range, signal loss, sudden noise changes);

[0096] Coordinate normalization: uniformly convert to the fuselage coordinate system to construct a 360° real-time point cloud map;

[0097] 2) Feature layer fusion (middle layer)

[0098] An improved extended Kalman filter (EKF) is used to fuse multi-source data to estimate the true position, velocity, and acceleration of obstacles.

[0099] Confidence weighting: Weights are dynamically assigned based on the environment (rainy day: radar weight 80%; sunny day: visual weight 60%; near range: ultrasound weight 70%).

[0100] Conflict resolution: When data from multiple sensors is inconsistent, a two-out-of-three voting method is used (at least two types of sensors must be consistent for the decision to be valid).

[0101] 3) Integration at the decision-making level (top level)

[0102] Preset collision risk model: Risk coefficient R;

[0103] Grading threshold:

[0104] Early warning (R1): When the distance d = 1.5~3m, the flight control pre-deceleration, buffer component 5 and elastic support mechanism 6 are pre-energized and ready to go;

[0105] Warning (R2): When d = 0.3~1.5m, the system enters the standby state;

[0106] Emergency Trigger (R3): When d≤0.3m, the buffer component 5 and the elastic support mechanism 6 are triggered immediately, but the triggering time of the buffer component 5 is 10ms~15ms earlier than the triggering time of the elastic support mechanism 6, so that the elastic support mechanism 6 can support the folding buffer wing 53.

[0107] 2. Redundancy and fault tolerance mechanism (fault isolation + seamless switching)

[0108] Fault detection: Real-time monitoring of sensor heartbeat, signal strength, and data continuity; fault identification time ≤ 5ms.

[0109] Isolation and degradation: When a single sensor fails, it is automatically isolated and the remaining sensors take over without affecting the triggering function;

[0110] Example: Visual failure → Radar + ultrasound function normally;

[0111] Example: Radar failure → Vision + Ultrasound function normally;

[0112] Workflow (millisecond-level closed loop):

[0113] Phase 1: Normal cruise (no risk); all three types of sensors operate at full power, 500Hz high-frequency scanning; the data processing and control unit outputs an environmental map, with a risk factor R≈0; buffer system: buffer component 5 and elastic support mechanism 6 are retracted, minimizing wind resistance;

[0114] Phase 2: Early warning (d=1.5~3m, R=R1); Radar / visual detection of obstacles, predicted collision time TTC≤1s; Flight control executes pre-deceleration; Buffer system: The power supply current of buffer component 5 and elastic support mechanism 6 is increased, and it is preheated and ready (response shortened to 3ms).

[0115] Phase 3: Warning (d=0.3~1.5m, R=R2); at least two types of sensors confirm the obstacle, TTC≤0.3s; high-confidence trigger command for data processing and control unit; buffer system: buffer component 5 and elastic support mechanism 6 are in a ready-to-trigger state (can be deployed immediately within 10ms);

[0116] Phase 4: Emergency Trigger (d≤0.3m); Conditions: Simultaneous confirmation by radar, vision, and ultrasound; Zero-delay output of trigger command (command transmission time≤100μs); Folding buffer wing 53 and support column 6213 fully deployed, deployment time≤12ms, protective ring adaptively deflects to absorb energy;

[0117] Phase 5: Post-collision reset; after the impact ends, the sensors detect no obstacles and the risk is cleared; the buffer assembly 5 and the elastic support mechanism 6 are de-energized, the folding buffer wing 53 and the support column 6213 retract and reset → system self-test → go-around.

[0118] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0119] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A collision avoidance device for rotary-wing unmanned aerial vehicles (UAVs), comprising a buffer system and a multi-mode redundancy sensing trigger module, wherein the buffer system is electrically connected to the multi-mode redundancy sensing trigger module, characterized in that, The multi-mode redundant perception trigger module is used to detect obstacles and trigger the deployment of the buffer system, which is used to absorb impact energy and protect the UAV body. The buffer system includes four buffer components and four anti-collision cages; The four buffer components are respectively installed on the four arms of the UAV body, and the axes of the four buffer components are all coincident. The four anti-collision cages are semi-enclosed hollow structures, respectively installed at the ends of the four arms, and surround the rotor of the UAV body inside them. The buffer assembly includes two arc-shaped frames, both of which are mounted on the support arm via a clamping plate. Each arc-shaped frame has a groove at both ends, and a folding buffer wing is installed inside the groove. The folding buffer wing includes an internal skeleton and an external protective film. The internal skeleton is a diamond-shaped mesh structure woven from nickel-titanium superelastic shape memory alloy wires. Multiple diamond-shaped mesh structures are arranged in parallel and evenly. The beginning and end of the diamond-shaped mesh alloy wires are electrically connected to a multi-mode redundant sensing trigger module via wires. The external protective film is woven and covered with ultra-high molecular weight polyethylene fiber.

2. The anti-collision device for rotorcraft unmanned aerial vehicle (UAV) flight according to claim 1, characterized in that, The buffer system also includes four elastic support mechanisms, which are respectively installed around the main body of the UAV. The elastic support mechanism includes a mounting frame, a mounting plate, and a foldable support assembly. The mounting plate is mounted on the fuselage of the drone body, the mounting frame is connected above the mounting plate, and the foldable support assembly is installed inside the mounting frame. The foldable support assembly includes two sliders, two support rods, two shape memory alloy springs, and a support block. The two sliders are slidably mounted inside the mounting frame. The two support rods are rotatably mounted on opposite sides of the two sliders. A torsion spring connects the sliders and the support rods. The two support rods are rotatably connected to the support block via pins, which are fixedly connected to the support rods. The two shape memory alloy springs are mounted on opposite sides of the two sliders. One end of each shape memory alloy spring is connected to the mounting frame, and the other end abuts against the two sliders. Both ends of the shape memory alloy springs are electrically connected to a multi-mode redundant sensing trigger module via wires.

3. The anti-collision device for rotorcraft unmanned aerial vehicle (UAV) flight according to claim 2, characterized in that, The elastic support mechanism also includes two retractable support components; The retractable support assembly includes a support column, a piston column, a piston plate, a compression spring, and a pressure box. The support block has a storage groove and an air chamber. The piston column is slidably installed in the storage groove. The support column is fixedly connected to the end of the piston column. The piston plate is slidably installed in the air chamber. The compression spring is connected between the piston plate and the air chamber. The air chamber is connected to the storage groove through a connecting air hole. The pressure box is fixedly connected to the side of the piston plate away from the storage groove. A cam is fixedly connected to the side of the pin shaft, and the cam contacts the side of the pressure box.

4. The anti-collision device for rotorcraft unmanned aerial vehicle (UAV) flight according to claim 3, characterized in that, The two retractable support components are symmetrically distributed about the central axis of the support block, and the two support posts extend from the upper and lower end faces of the support block, respectively.

5. The anti-collision device for rotorcraft unmanned aerial vehicle (UAV) flight according to claim 1, characterized in that, The multi-mode redundancy sensing trigger module includes a hardware module and a software module; The hardware module consists of a millimeter-wave radar unit, an infrared TOF+ polarization vision unit, an ultrasonic array unit, and a data processing and control unit, which are deployed in a "far-medium-near" gradient. The software module adopts AI-integrated voting triggering logic, including a three-level data fusion mechanism and a redundancy fault tolerance mechanism.

6. The anti-collision device for rotorcraft unmanned aerial vehicle (UAV) flight according to claim 5, characterized in that, The millimeter-wave radar unit uses four 77GHz 4D millimeter-wave radars, symmetrically embedded at the four corners of the UAV fuselage, with each group covering a 90° horizontal field of view and ±45° vertical field of view. The infrared TOF+ polarization vision unit consists of 8 groups, with 1 group arranged on each of the upper and lower arms. The ultrasonic array unit consists of four groups, which are respectively located at the bottom and four corners of the machine body.

7. The anti-collision device for rotorcraft unmanned aerial vehicle (UAV) flight according to claim 5, characterized in that, The three-level data fusion mechanism includes data layer fusion, feature layer fusion, and decision layer fusion. The data layer fusion enables 1μs-level hard synchronization of each sensor, data validity verification, and coordinate normalization. The feature layer fusion employs an improved extended Kalman filter to fuse multi-source data, and performs confidence weighting and conflict resolution. The decision-making layer integrates a preset collision risk model and sets three levels of thresholds: pre-warning, early warning, and emergency trigger.

8. The anti-collision device for rotorcraft unmanned aerial vehicle (UAV) flight according to claim 5, characterized in that, The redundancy fault-tolerance mechanism can monitor the sensor status in real time, with a fault identification time of ≤5ms. When a single sensor fails, the faulty sensor is automatically isolated, and the remaining sensors take over the detection and triggering functions.

9. The anti-collision device for rotorcraft unmanned aerial vehicle (UAV) flight according to claim 5, characterized in that, The workflow of the multi-modal redundancy sensing triggering module includes five stages: Phase 1, Normal Cruise Operation: All three types of sensors operate at full power, the data processing and control unit outputs an environmental map, the buffer system is in a retracted state, and wind resistance is reduced to a minimum; Phase 2, Early Warning: When the millimeter-wave radar or vision unit detects an obstacle and predicts a collision time TTC ≤ 1s, the flight control system performs pre-deceleration, the buffer system enters a preheating standby state, and the response time is shortened to 3ms; Phase 3, Warning: At least two types of sensors confirm the presence of an obstacle, the collision time TTC is ≤0.3s, the data processing and control unit outputs a high-confidence trigger command, the buffer system enters the ready-to-trigger state, and can be deployed immediately within 10ms; Phase 4, Emergency Trigger: All three types of sensors simultaneously detect the obstacle, triggering a zero-delay output command that fully deploys the folding buffer wings and support columns; Phase 5, Post-Collision Reset: After the impact, the sensors detect no obstacles and the risk factor is cleared to zero. The buffer system is reset, the system performs a self-check, and after the self-check is passed, the drone resumes normal flight.

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