A multirotor eVTOL nacelle disengageable system

Abstract

The application provides a multi-rotor eVTOL pod detachable system, and relates to the technical field of emergency safety of electric vertical take-off and landing aircrafts, and comprises a detachable system and a rotor system, the detachable system is detachably assembled in the central area of the lower part of the mainframe; the detachable system comprises a pod module, a separation control module, a multi-mode deceleration landing module, an attitude control module, an environment sensing and obstacle avoidance module, a post-landing detachment module and a water floating airbag device, and the independent isolation type lifesaving frame structure: by designing the pod module as a separable independent module, when the mainframe, the rotor system or the power battery has a serious failure, the passengers or important loads can be completely isolated from the danger source, the survival probability under the failure working condition is improved from the root, and the problem that the multi-rotor eVTOL lacks effective technical means for quickly separating the passenger cabin from the failure aircraft body and performing controllable lifesaving under the extreme failure working condition is solved.

Description

Technical Field

[0001] This invention relates to the field of emergency safety technology for electric vertical takeoff and landing (eVTOL) aircraft, and in particular to a multi-rotor eVTOL pod detachable system. Background Technology

[0002] With the booming development of the low-altitude economy, electric vertical takeoff and landing (eVTOL) aircraft have shown broad application prospects in urban air traffic, emergency rescue, and logistics transportation. Multi-rotor eVTOLs have advantages such as vertical takeoff and landing, simple structure, and convenient operation. However, when they lose power or flight control fails, they lack the gliding ability of fixed-wing aircraft or the autorotation descent ability of helicopters, and their attitude is easily out of control, posing significant safety risks.

[0003] To address the aforementioned risks, existing emergency landing technologies mainly encompass whole-aircraft parachute recovery, separate parachute escape, automatic parachute detachment, and detachable cabin concepts. Regarding whole-aircraft parachute detachment, research indicates that while the Parachute Recovery System (PRS) is a mature and widely used technology, its application in manned eVTOL suffers from drawbacks such as excessive descent rate and poor attitude controllability, and it is highly susceptible to collisions with buildings or cables in complex urban environments. To solve this problem, separate escape technology has emerged. Chinese invention patent application CN114248927A discloses a separate parachute emergency detachment system for eVTOL manned unmanned aerial vehicles, achieving escape by separating the upper frame from the lower crew cabin. While this solution establishes the basic concept of "cabin separation + parachute detachment," it lacks a systematic design for the attitude stabilization, multi-mode buffer landing, and environmental perception and obstacle avoidance of the separated cabin section, making it difficult to meet the high safety requirements of complex urban environments. Furthermore, the automatic parachute detachment device disclosed in Chinese utility model CN217022903U mainly focuses on preventing ground dragging after landing and does not have an in-flight emergency escape function; while the concept of detachable cabins in the civil aviation field is still in the conceptual stage and has not yet been engineered for the urban operating environment of multi-rotor eVTOL.

[0004] In summary, the existing technology lacks a comprehensive detachment system for multi-rotor eVTOL aircraft that can reliably separate the cockpit / pod, perform multi-mode buffer landing, and actively avoid obstacles in complex urban environments. Specifically, the following technical problems exist: 1. After a multi-rotor eVTOL malfunctions, attitude control is lost and rescue methods are lacking. Multi-rotor eVTOLs lack the gliding ability of fixed-wing aircraft and the autorotation descent ability of helicopters. Once power failure or flight control failure occurs, attitude control is easily lost and the aircraft will fall freely. Existing technology lacks effective technical means to quickly separate the crew cabin from the malfunctioning aircraft and carry out controlled rescue under extreme failure conditions. 2. Excessive impact of whole-aircraft parachute landing: When the existing whole-aircraft parachute recovery system is applied to manned eVTOL, its descent rate still results in a large landing impact. In complex terrain or urban environments, it is very easy to cause spinal injuries or structural damage to the occupants, which is difficult to meet the safety requirements of manned aircraft for "soft" landing. 3. Uncontrollable landing point and secondary damage during parachute descent: Traditional parachutes are significantly affected by wind fields, resulting in poor landing accuracy. In urban environments, they are prone to colliding with buildings or cables or being dragged in complex terrain, causing secondary damage. Existing technology lacks the ability to actively control the descent trajectory and cannot achieve the function of avoiding obstacles and selecting a safe landing area. 4. Existing separation schemes lack systematic life-saving design. Although existing separation escape schemes achieve cabin separation, they lack active attitude stabilization of the separated cabin sections, multi-mode deceleration backup, and anti-drag design after landing. They are difficult to cope with airflow interference and the risk of main parachute failure, and cannot meet the high reliability requirements for occupant safety in complex urban environments. 5. The separated cabin lacks active obstacle avoidance and trajectory planning methods. In the face of complex urban environments, the separated crew cabin lacks miniaturized environmental perception configuration and online trajectory planning algorithms within a short time window. It cannot work in coordination with attitude control and deceleration systems, making it difficult to achieve active obstacle avoidance and "optimal landing". 6. The reliability and safety of the manned separation mechanism are insufficient. Existing separation mechanisms are difficult to meet the high safety standards of manned aircraft, namely, preventing accidental triggering under normal flight high load, highly reliable unlocking in emergency situations and no impact hazards. It is also difficult to achieve a locking-release mechanism with high load capacity, low impact and redundant design under limited space and weight constraints. 7. Insufficient coordinated control of multi-mode deceleration and buffering. Single parachute deceleration is difficult to meet the escape needs of different altitudes and different failure modes. Existing technology lacks a solution for integrated and coordinated control of deceleration methods such as main parachute, reserve parachute, and buffer airbag, making it difficult to achieve optimal landing impact control within the full envelope. Summary of the Invention

[0005] This invention relates to a detachable multi-rotor eVTOL pod system. Through highly integrated mechanical structure, aerodynamic deceleration, active control and environmental perception technologies, it solves key technical problems of existing manned eVTOLs in complex urban environments, such as lack of emergency escape means, uncontrollable attitude and large landing impact, significantly improving the safety of urban air traffic.

[0006] This invention provides a detachable system for a multi-rotor eVTOL pod, specifically comprising: a detachment system and a rotor system. The detachment system is detachably mounted in the central area of ​​the lower part of the main frame. The rotor system is symmetrically arranged on the outer periphery of the main frame, fixedly connected to the main frame by a mechanical load-bearing structure, and electrically connected to the power battery and avionics flight control system through an electrical wiring harness. The detachment system includes a pod module, a separation control module, a multi-mode deceleration and landing module, an attitude control module, an environmental perception and obstacle avoidance module, a post-landing detachment module, and a water-floating airbag device. The pod module is an independent cabin module that carries occupants or loads. The pod module is detachably connected to the main frame through the locking and releasing mechanism of the separation control module. The separation control module includes an emergency condition detection unit, a control unit, and a locking and releasing mechanism. The emergency condition detection unit collects real-time data on the aircraft's flight status, power, flight control, and battery status. The control unit has built-in fault tree analysis logic and adopts a triple-redundant fault-tolerant architecture to determine whether preset emergency conditions are met. When the emergency conditions are met, it outputs an unlocking pulse signal to the locking and releasing mechanism, simultaneously cutting off the electrical connection interface between the main frame and the pod module. The locking and releasing mechanism is symmetrically arranged in three or four sets along the pod's center of gravity to form a statically indeterminate constraint structure. The multi-mode deceleration and landing module is located at the top and bottom of the separation system and includes a main parachute, a backup parachute, a cushioning airbag device, a parachute compartment, a parachute compartment canopy, and an ejection mechanism. It is used to achieve gradual deceleration and landing cushioning after emergency separation. The main parachute is folded and stored in the internal cavity of the parachute compartment, and the bottom end of the main parachute's parachute lines is fixedly connected to the main load-bearing joint at the top of the separation system. The top of the main parachute canopy is connected to the guide parachute via a connecting strap, and the guide parachute's traction end is fixedly connected to the traction strap inside the parachute compartment canopy. The backup parachute... The parachutes are configured in two sets, symmetrically arranged in the reserved compartments at the top of the release system on both sides of the parachute compartment. The bottom ends of the parachute lines of the backup parachute are fixed to the independent load-bearing points at the top of the release system. The buffer airbag device is arranged at the bottom and sides of the pod module. The parachute compartment is located in the middle of the top of the release system, and a parachute compartment cover is fitted and fastened to the top opening of the parachute compartment. The ejection mechanism is fixed to the top side wall inside the parachute compartment. The actuating end of the ejection mechanism is connected to the locking structure inside the parachute compartment cover, which locks the parachute compartment cover at the opening of the parachute compartment under normal conditions. The attitude control module is used to actively stabilize the detachment attitude from the system and respond to trajectory correction commands after the pod separates. The environmental perception and obstacle avoidance module is used to build an environmental model in real time, match the map database, plan the optimal descent trajectory, and output trajectory correction instructions to the attitude control module. The post-landing detachment module is used to monitor parachute tension and disconnect the main parachute from the detachment system when there is a risk of ground wind dragging. The floating airbag device is built into the lower side of the pod module and is used to provide buoyancy when landing in water. The pod module includes an electrical connection interface, a cockpit frame, and a seat system. The electrical connection interface is located at the mating surface between the top of the cockpit frame and the main frame, and is electrically connected to the power supply bus and communication bus of the power battery and avionics flight control system. The cockpit frame adopts a hybrid structure of carbon fiber composite material and aluminum alloy frame. The external skin and key load-bearing components are laid and cured with T700 grade carbon fiber prepreg. The main body of the cockpit frame is welded and formed by aerospace-grade 7075 aluminum alloy. The seat system is integrally die-cast and fixed inside the cockpit frame by aerospace-grade 7075 aluminum alloy. The seat system is equipped with safety straps and a seat.

[0007] Furthermore, the locking and releasing mechanism includes a lock body made of high-strength alloy steel, a retractable locking pin, a spring, and an electromagnet; the retractable locking pin is slidably assembled in the guide hole of the lock body, and the shear resistance safety factor of a single retractable locking pin is not less than 1.5, and the impact load it can withstand is not less than 10G; under normal flight conditions, the retractable locking pin is locked in the pod lock hole by the spring preload and the electromagnet holding force, and the overall tensile strength is greater than 20kN; when unlocking, the electromagnet generates a reverse magnetic field to overcome the spring preload and retract the locking pin to complete the unlocking, and simultaneously triggers a mechanical switch to cut off the electrical connection interface.

[0008] Furthermore, the data collected by the emergency condition detection unit includes the three-axis angular velocity and linear acceleration of the inertial measurement unit, the altitude, airspeed, and position information of the barometric altimeter and GPS / BeiDou, the speed, torque, and temperature of the motor controller, the computational redundancy and sensor health of the flight control system, and the voltage, current, temperature, and smoke detection signal of the battery management system. The control unit has preset emergency conditions including any one of the following: Power failure mode: The aircraft's vertical descent rate is greater than 5 m / s and all rotor speeds are below 20% of idle speed; Flight control failure mode: The deviation between flight control commands and attitude angle feedback exceeds the threshold and lasts for 2 seconds, or the flight control calculation margin is exhausted; Thermal runaway / fire mode: The battery temperature rise rate exceeds 5°C / s or the smoke concentration in the cabin triggers the alarm threshold; Structural failure mode: failure of critical connectors in the main frame or structural deformation exceeding a preset threshold; The unlocking pulse signal output by the control unit has a pulse width of 50ms to 100ms.

[0009] Furthermore, the ejection mechanism adopts a miniature explosive cord or spring ejection structure, which can open the parachute canopy and pull out the guide parachute within 20ms; The main parachute adopts a cross-shaped or ring sail structure. Under the condition of a detachment mass of 600kg, the canopy area is 80-100㎡, and the steady-state descent speed under standard atmospheric pressure is no more than 6m / s. The backup parachute canopy area is 50% of the main parachute area. It is independently arranged on both sides of the top of the cockpit and equipped with an independent pyrotechnic ejection mechanism for redundant deceleration in case the main parachute fails, becomes entangled, or is damaged.

[0010] Furthermore, the buffer airbag device is made of aramid Kevlar coated sealing material. The buffer airbag device has a built-in buffer airbag, vent, height sensor and first gas generator. The height sensor triggers the first gas generator at a height of 30m to 50m above the ground. The airbag inflation time is less than 150ms and the steady-state working pressure of the airbag is 0.2MPa to 0.35MPa. The buffer airbag device actively releases pressure and absorbs energy through the vent, controlling the vertical impact load on the occupant to within 25G.

[0011] Furthermore, the attitude control module includes an attitude control thruster, an attitude sensor, and an attitude control controller. The attitude control thruster is arranged in an H-shape or a cross shape around the separation system. It adopts a cold gas jet propulsion system or a micro solid rocket engine, with a single-unit thrust of 100N to 300N and a specific impulse of not less than 50s. The attitude sensor includes a high-precision fiber optic gyroscope and a MEMS accelerometer, with a sampling rate of not less than 200Hz; The attitude control controller employs a robust PID or adaptive control algorithm, calculates the control torque based on attitude feedback, and adjusts the pulse width jet to suppress roll, pitch, and yaw oscillations, ensuring an upright landing attitude. The attitude control controller receives trajectory correction commands from the environmental perception and obstacle avoidance module, and forms a glide ratio through lateral thrust to achieve 100m to 200m lateral displacement obstacle avoidance.

[0012] Furthermore, the environmental perception and obstacle avoidance module includes a solid-state lidar, a millimeter-wave radar, a binocular vision sensor, and a processing unit. The solid-state lidar has a horizontal field of view ≥120°, a vertical field of view ≥30°, and a detection range >100m, and is used to construct a three-dimensional terrain point cloud. The millimeter-wave radar operates in the 77GHz frequency band and is used for altitude measurement and detection of small obstacles such as cables. The binocular vision sensor is configured as two sets, symmetrically arranged on the front and left and right sides of the bottom of the pod module, and fixed to the mounting base at the bottom of the cockpit frame by a vibration damping bracket. The lens faces diagonally downward, and the field of view covers the landing area directly below and in front of the cockpit. The processing unit is an embedded computing platform that runs SLAM and path planning algorithms, integrates multi-sensor data, urban digital maps, and a safe landing area database, and generates obstacle avoidance trajectory correction commands when it detects obstacles or crowds below and sends them to the attitude control module.

[0013] Furthermore, the post-landing detachment module includes a tension sensor and a mechanical release hook. The tension sensor monitors the tension of the main parachute lines in real time. When the tension is continuously greater than 50N for more than 3 seconds, it is determined to be a risk of ground wind drag. The control unit triggers the electromagnetic release mechanism of the mechanical release hook to disconnect the main parachute connection. The mechanical release hook has both electric unlocking and manual emergency unlocking functions and is equipped with a manual unlocking handle.

[0014] Furthermore, the floating airbag device includes a water-sensitive sensor, a floating airbag, and a second gas generator; after the water-sensitive sensor detects the bottom immersion signal, it triggers the second gas generator to quickly inflate, and the floating airbag forms a floating boat structure on both sides and the bottom of the cabin, with a total buoyancy of not less than 1.5 times the weight of the system detached from the cabin.

[0015] This invention provides a detachable multi-rotor eVTOL pod system, which has the following advantages: 1. Independent isolation rescue architecture: By designing the pod module as a separable independent module, it can completely isolate the crew or important load from the source of danger in the event of a serious failure of the main frame, rotor system or power battery, thereby improving the survival probability under failure conditions from the root.

[0016] 2. Multi-mode coordinated deceleration and buffering: The system employs a multi-mode deceleration scheme that combines the main parachute, backup parachute, and buffer airbag device with active attitude control to achieve adjustable descent speed and controllable landing attitude. The "inflation-decompression" energy absorption mechanism of the buffer airbag controls the landing impact within the physiological tolerance limit of the human body, significantly reducing the risk of landing damage.

[0017] 3. Active obstacle avoidance capability in urban environments: By introducing an environmental perception and obstacle avoidance module, a three-dimensional model of the environment below is constructed in real time through multi-sensor fusion. Combined with a pre-set safe landing area database, the trajectory is planned online. In complex urban environments, it can actively select a better landing point and avoid obstacles such as buildings and cables, while ensuring the safety of people and property on the ground.

[0018] 4. All-scenario post-processing safety design: After landing, the parachute can automatically detach to prevent secondary damage from ground wind drag. It also integrates a water-floating airbag device, which can adapt to various geographical environments such as land and water, and comprehensively reduce the risk of secondary damage. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings of the embodiments will be briefly described below.

[0020] The accompanying drawings described below are only related to some embodiments of the invention and are not intended to limit the invention.

[0021] In the attached diagram: Figure 1A schematic diagram of the external structure of the multi-rotor eVTOL of the present invention is shown; Figure 2 A schematic diagram of the internal structure of the multi-rotor eVTOL of the present invention is shown; Figure 3 A schematic diagram of the bottom structure of the multi-rotor eVTOL of the present invention is shown; Figure 4 A schematic diagram of the detachment system structure of the multi-rotor eVTOL of the present invention is shown; Figure 5 This diagram shows the structure of the multi-rotor eVTOL of the present invention in the detachment system detachment state; Figure 6 This diagram shows the structure of the multi-rotor eVTOL detachment system in the landing state of the present invention; Figure 7 The present invention is shown Figure 6 A magnified view of the structure at point A in the middle; Figure 8 A schematic diagram of the connection and locking / releasing mechanism between the pod module and the main frame of the present invention is shown. Figure 9 This diagram illustrates the multi-mode deceleration landing and attitude control principle framework of the detached pod module of the present invention. Figure 10 This diagram illustrates the working principle framework of the environmental perception and obstacle avoidance module of the present invention. Figure 11 A flowchart of the emergency escape control method of the present invention is shown; List of reference numerals 1. Detachment System; 2. Main Frame; 3. Rotor System; 4. Power Battery and Avionics / Flight Control System; 11. Pod Module; 111. Electrical Connection Interface; 112. Cockpit Frame; 113. Seat System; 1131. Safety Straps; 1132. Seat; 12. Detachment Control Module; 121. Emergency Condition Detection Unit; 122. Control Unit; 123. Locking Release Mechanism; 1231. Lock Body; 1232. Retractable Locking Pin; 1233. Spring; 1234. Electromagnet; 13. Multi-Mode Deceleration and Landing Module; 131. Main Parachute; 132. Backup Parachute; 133. Cushioning Airbag Device; 1331. Altitude Sensor; 1332. First Gas Generator; 1333. Exhaust Port; 133 4. Buffer airbag; 134. Parachute compartment; 135. Parachute compartment cover; 136. Ejection mechanism; 14. Attitude control module; 141. Attitude control thruster; 1411. Cold gas jet propulsion system; 1412. Attitude sensor; 14121. High-precision fiber optic gyroscope; 14122. MEMS accelerometer; 15. Environmental perception and obstacle avoidance module; 151. Solid-state lidar; 152. Millimeter-wave radar; 153. Binocular vision sensor; 154. Processing unit; 16. Post-landing release module; 161. Tension sensor; 162. Mechanical release hook; 1621. Electromagnetic release mechanism; 17. Water-floating airbag device; 171. Water-sensitive sensor; 172. Floating airbag; 173. Second gas generator. Detailed Implementation

[0022] Example: Please refer to Figures 1 to 11 : This invention proposes a detachable multi-rotor eVTOL pod system, applicable to low-altitude scenarios such as urban air traffic, emergency rescue, and material delivery. It addresses industry pain points such as loss of overall attitude control and lack of reliable rescue methods in the event of power failure or flight control malfunction in multi-rotor eVTOL systems. The system includes: a detachment system 1, a main frame 2, a rotor system 3, and a power battery and avionics / flight control system 4. The detachment system 1 is detachably mounted in the lower central area of ​​the main frame 2. The rotor system 3 is symmetrically arranged on the outer periphery of the main frame 2 and is rigidly connected to the main frame 2 via a high-rigidity mechanical load-bearing structure. It is electrically connected to the power battery and avionics / flight control system 4 via electrical wiring harnesses, providing the lift and control torque required for vertical takeoff and landing and maneuvering flight.

[0023] The detachment system 1, as an independent rescue unit, can achieve physical and electrical dual isolation from the faulty main frame. It includes a pod module 11, a separation control module 12, a multi-mode deceleration landing module 13, an attitude control module 14, an environmental perception and obstacle avoidance module 15, a post-landing detachment module 16, and a water-floating airbag device 17.

[0024] The pod module 11 is an independent cabin module that carries occupants or payloads. The pod module 11 is detachably connected to the main frame 2 via the locking and releasing mechanism 123 of the separation control module 12. The pod module 11 includes an electrical connection interface 111, a cockpit frame 112, and a seat system 113. The electrical connection interface 111 is located at the mating surface between the top of the cockpit frame 112 and the main frame 2, and is electrically connected to the power supply bus and communication bus of the power battery and avionics flight control system 4 to realize the power supply and signal interaction of the whole aircraft under normal flight conditions. The cockpit frame 112 adopts a hybrid structure of carbon fiber composite material and aluminum alloy frame. The external skin and key load-bearing components are laid and cured with T700 grade carbon fiber prepreg. The main body of the cockpit frame 112 is welded and formed with aerospace-grade 7075 aluminum alloy. The overall structural strength meets the emergency landing crash load resistance index of airworthiness regulations and can withstand the impact load under emergency fall conditions without structural disintegration. The seat system 113 is integrally die-cast with aerospace-grade 7075 aluminum alloy and fixed inside the cockpit frame 112. The seat system 113 is equipped with safety straps 1131 and seats 1132, which can reliably restrain the occupants on the seats 1132 and reduce secondary injuries caused by landing impact.

[0025] The separation control module 12 is the decision-making center of this system, including an emergency condition detection unit 121, a control unit 122, and a locking and releasing mechanism 123. The emergency condition detection unit 121 collects multi-dimensional data on the aircraft's flight status, power, flight control, and battery status in real time. The control unit 122 incorporates fault tree analysis logic and adopts a triple-redundant fault-tolerant architecture. It relies on a multi-channel majority voting mechanism to avoid the risk of false triggering or failure to act due to single-point failures. It is used to determine whether preset emergency conditions are met, and when the emergency conditions are met, it outputs an unlocking pulse signal to the locking and releasing mechanism 123, simultaneously cutting off the electrical connection interface 111 between the main frame 2 and the pod module 11, achieving synchronous mechanical and electrical disconnection and avoiding the risks of wiring harness pulling, short circuits, and sparking during the separation process. Three or four sets of locking and releasing mechanisms 123 are symmetrically arranged along the pod's center of gravity to form a statically indeterminate constraint structure. The synchronous action of multiple mechanisms eliminates the risk of separation tilt and failure caused by jamming of a single mechanism.

[0026] The locking and releasing mechanism 123 includes a lock body 1231 made of high-strength alloy steel, a retractable locking pin 1232, a spring 1233, and an electromagnet 1234. The retractable locking pin 1232 is slidably assembled in the guide hole of the lock body 1231. The shear resistance safety factor of a single retractable locking pin 1232 is not less than 1.5, and the impact load it can withstand is not less than 10G. Under normal flight conditions, the retractable locking pin 1232 is locked in the pod lock hole by the preload of the spring 1233 and the holding force of the electromagnet 1234, resulting in a high overall tensile strength. With a current of 20kN, the pod is designed to prevent unexpected detachment of the aircraft under conditions of severe maneuvering and strong airflow disturbance. During unlocking, the electromagnet 1234 generates a reverse magnetic field to overcome the preload of the spring 1233 and retract the locking pin to complete the unlocking. Simultaneously, a mechanical switch is triggered to cut off the electrical connection interface 111. The electromagnet 1234 drive serves as the main unlocking path and can be equipped with an auxiliary pyrotechnic unlocking system as a hot backup. When the electromagnet 1234 circuit fails, the locking pin is forcibly released by the pyrotechnic drive, further enhancing the safety redundancy in manned scenarios.

[0027] The emergency condition detection unit 121 collects data including the three-axis angular velocity and linear acceleration of the inertial measurement unit, the altitude, airspeed, and position information of the barometric altimeter and GPS / BeiDou, the speed, torque, and temperature of the motor controller, the calculation redundancy and sensor health of the flight control system, and the voltage, current, temperature, and smoke detection signals of the battery management system. The multi-source sensor data are cross-checked to avoid misjudgment of faults caused by the failure of a single sensor. The control unit 122 presets any of the following emergency conditions: Power failure mode: The vertical descent rate of the aircraft is greater than 5 m / s and the rotational speed of all rotors is less than 20% of the idle speed, indicating that the entire aircraft has lost thrust and is entering an uncontrollable fall; Flight control failure mode: The deviation between the flight control command and the attitude angle feedback exceeds the threshold and lasts for 2 seconds, or the flight control calculation margin is exhausted, and the aircraft loses its three-axis attitude control capability; Thermal runaway / fire mode: The battery temperature rise rate exceeds 5℃ / s or the smoke concentration in the cabin triggers the alarm threshold, indicating a risk of fire and explosion; Structural failure mode: The key connecting parts of the main frame 2 are broken or the structural deformation exceeds the preset threshold, and the load-bearing structure of the entire aircraft is damaged; The unlocking pulse signal output by the control unit 122 has a pulse width of 50ms to 100ms. This pulse width range can ensure that the locking and releasing mechanism 123 can reliably complete the unlocking action, and can also avoid the overheating of the device and the ineffective loss of electrical energy caused by prolonged power supply.

[0028] The multi-mode deceleration and landing module 13 is located at the top and bottom of the separation system 1, and includes a main parachute 131, a backup parachute 132, a buffer airbag device 133, a parachute compartment 134, a parachute compartment cover 135, and an ejection mechanism 136. It is used to achieve gradual deceleration and landing buffer after emergency separation, accommodating both high-altitude long-duration stable descent and low-altitude emergency rescue scenarios. The main parachute 131 is folded and stored in the internal cavity of the parachute compartment 134, and the bottom end of the parachute lines of the main parachute 131 is fixedly connected to the main load-bearing joint at the top of the separation system 1. The top of the canopy of the main parachute 131 is connected to the guide parachute via a connecting strap, and the traction end of the guide parachute is fixedly connected to the traction strap inside the parachute compartment cover 135. Two sets of backup parachutes 132 are symmetrically arranged. The spare parachute 132 has its parachute ropes fixed to an independent load-bearing point on the top of the release system 1 on both sides of the parachute compartment 134, with the bottom end of the ropes fixed to the independent load-bearing point on the top of the release system 1, independent of the main parachute's force transmission path; the buffer airbag device 133 is arranged at the bottom and sides of the pod module 11, taking into account both bottom vertical impact and lateral collision protection; the parachute compartment 134 is located in the middle of the top of the release system 1, and the top opening of the parachute compartment 134 is fitted with a parachute compartment cover 135; the ejection mechanism 136 is fixed to the top side wall inside the parachute compartment 134, and the actuating end of the ejection mechanism 136 is connected to the locking structure inside the parachute compartment cover 135, locking the parachute compartment cover 135 at the opening of the parachute compartment 134 under normal conditions, preventing the parachute compartment cover 135 from being accidentally opened during flight.

[0029] The ejection mechanism 136 adopts a miniature explosive cord or spring ejection structure, which can eject the parachute canopy 135 and pull out the guide parachute within 20ms. The main parachute 131 adopts a cross-shaped or ring sail parachute structure, which has the advantages of high opening stability and small swing amplitude. Under the condition of a detachment mass of 600kg, the canopy area is 80-100㎡, and the steady-state descent speed under standard atmospheric pressure is no more than 6m / s. The backup parachute 132 has a canopy area of ​​50% of that of the main parachute 131. It is independently arranged on both sides of the top of the cockpit and equipped with an independent pyrotechnic ejection mechanism. It is used for redundant deceleration in case of main parachute failure, entanglement or damage, and serves as a backup deceleration method after main parachute failure.

[0030] The airbag device 133 is made of aramid Kevlar coated sealing material, which is tear-resistant and impact-resistant. The airbag device 133 contains an airbag 1334, an exhaust port 1333, a height sensor 1331, and a first gas generator 1332. The height sensor 1331 triggers the first gas generator 1332 at a height of 30m to 50m above the ground. The airbag inflation time is less than 150ms, and the steady-state working pressure of the airbag is 0.2MPa to 0.35MPa. The airbag device 133 actively releases pressure and absorbs energy through the exhaust port 1333. When the airbag is compressed at the moment of landing impact, the internal gas is released directionally from the exhaust port 1333, realizing the controllable dissipation of impact energy, controlling the vertical impact load of the occupant to within 25G, meeting the physiological tolerance limit of the human body, and reducing the risk of spinal cord injury.

[0031] Attitude control module 14 is used to actively stabilize the attitude of the separation system 1 after the pod separates and respond to trajectory correction commands, overcoming the roll and yaw problems caused by mechanical disturbances and high-altitude wind disturbances at the moment of separation, while providing lateral maneuverability for obstacle avoidance; attitude control module 14 includes attitude control thruster 141, attitude sensor 1412 and attitude control controller. Attitude control thruster 141 is arranged in an H-shape or cross shape around the separation system 1, using a cold gas jet propulsion system 1411 or a micro solid rocket motor, with a single-unit thrust of 100N to 300N and a specific impulse of not less than 50s; attitude sensor 14... The system includes a high-precision fiber optic gyroscope 14121 and a MEMS accelerometer 14122 with a sampling rate of no less than 200Hz, which can capture and separate transient attitude disturbances at high speed. The attitude control controller adopts a robust PID or adaptive control algorithm, calculates the control torque based on attitude feedback and adjusts the pulse width jet to suppress roll, pitch and yaw oscillations and ensure an upright landing attitude. The attitude control controller receives trajectory correction commands from the environmental perception and obstacle avoidance module 15 and forms a glide ratio through lateral thrust to achieve lateral displacement obstacle avoidance of 100m to 200m, thus overcoming the limitation of traditional parachutes that can only passively drift with the wind.

[0032] The environmental perception and obstacle avoidance module 15 is used to build environmental models in real time, match map databases, plan the optimal descent trajectory, and output trajectory correction commands to the attitude control module 14, adapting to complex low-altitude environments with dense urban buildings and cables. The environmental perception and obstacle avoidance module 15 includes a solid-state lidar 151, a millimeter-wave radar 152, a binocular vision sensor 153, and a processing unit 154. The solid-state lidar 151 has a horizontal field of view ≥120°, a vertical field of view ≥30°, and a detection range >100m, and is used to build three-dimensional terrain point clouds. The millimeter-wave radar 152 operates in the 77GHz frequency band and has the ability to penetrate rain, fog, and smoke, and is used for altimetry and line detection. Small obstacles such as cables; the binocular vision sensor 153 is configured in two sets, symmetrically arranged on the front and left and right sides of the bottom of the pod module 11, and fixed to the mounting base at the bottom of the cabin frame 112 by vibration damping brackets, with the lens facing diagonally downward, and the field of view covering the landing area directly below and in front of the cabin; the processing unit 154 is an embedded computing platform that runs SLAM and path planning algorithms, integrates multi-sensor data, urban digital maps and safe landing area databases. The database pre-stores suitable landing areas such as squares, green spaces, rooftop helipads, and water areas. When obstacles or crowds are detected below, obstacle avoidance trajectory correction commands are generated and sent to the attitude control module 14.

[0033] The post-landing release module 16 monitors parachute line tension and disconnects the main parachute 131 from the release system 1 when there is a risk of ground wind dragging, preventing the parachute from being dragged by the wind and causing the gondola to roll and resulting in secondary injury to the occupants. The post-landing release module 16 includes a tension sensor 161 and a mechanical release hook 162. The tension sensor 161 monitors the parachute line tension of the main parachute 131 in real time. When the tension is greater than 50N for more than 3 seconds, it is determined to be a risk of ground wind dragging. The control unit 122 triggers the electromagnetic release mechanism 1621 of the mechanical release hook 162 to disconnect the main parachute. The mechanical release hook 162 has both electric unlocking and manual emergency unlocking functions. It is equipped with a conspicuous manual unlocking handle, which allows the occupants or ground rescue personnel to manually perform the parachute release operation, achieving electric-manual dual redundancy.

[0034] The floating airbag device 17 is built into the lower side of the gondola module 11 to provide buoyancy when landing in water. The floating airbag device 17 includes a water sensor 171, a floating airbag 172 and a second gas generator 173. After the water sensor 171 detects the bottom water immersion signal, it triggers the second gas generator 173 to inflate rapidly. The floating airbag 172 forms a floating boat structure on both sides and the bottom of the cabin. The total buoyancy is not less than 1.5 times the weight of the detached system 1. It has buoyancy redundancy to ensure that the gondola floats stably in the positive direction after landing in the water, prevents water from entering and sinking, and buys time for rescue on the water.

[0035] This embodiment also provides an emergency detachment control method for a multi-rotor eVTOL pod detachable system, including the following steps: Step 1, real-time monitoring and data fusion: After the system is powered on, the detachment control module 12 collects IMU data, barometric altimeter data, GPS / BeiDou positioning data, motor controller feedback signals, and battery management system status data in real time at a frequency of 100Hz; the control unit 122 performs Kalman filtering fusion on the multi-source data, eliminates sensor outliers, and estimates the current true position, speed, and attitude of the aircraft; Step 2, Fault Diagnosis and Decision-Making: The control unit 122 performs diagnosis based on the preset fault judgment logic, cross-verifies the data from multiple sources of sensors to reduce the probability of false alarms; when any preset emergency condition is met, it is determined to be an unrecoverable emergency state and triggers the escape procedure. Step 3, Separation and Initial Attitude Adjustment: Within 10ms after determining that the emergency conditions are met, the control unit 122 outputs an unlocking signal, and the locking and releasing mechanism 123 operates synchronously. Under the action of gravity and the thrust of the separation spring 1233, the pod module 11 separates from the main frame 2 at a relative speed of 2m / s to 3m / s. The attitude control module 14 starts immediately in sync with the unlocking signal, and outputs maximum thrust to suppress the angular velocity disturbance at the moment of separation, ensuring that the attitude angle of the separation system 1 is stable within the error range of ±5° before the parachute opens, and avoiding attitude tilting that could cause the parachute to wrap around the pod. Step 4, Multi-mode deceleration sequence execution: 0.5 to 1 second after separation, after the separation system 1 and main frame 2 have maintained a safe distance of more than 20 meters to avoid the risk of the faulty main frame colliding with the pod, the ejection mechanism 136 launches the guide parachute and pulls out the main parachute 131 canopy; if the separation altitude is below 50 meters, which is a low-altitude dangerous condition, the control unit 122 directly triggers the early deployment of the buffer airbag 1334 and activates the backup parachute 132 to assist in deceleration; during the descent, when the altitude above the ground drops to 50 meters, the buffer airbag 1334 is fully inflated; Step 5, Environmental Perception and Trajectory Guidance: During the stable descent phase of the main parachute 131, the environmental perception and obstacle avoidance module 15 continuously scans the ground, generates a digital elevation model, and identifies dangerous targets such as buildings, high-voltage lines, and crowds, as well as safe zones such as green spaces and squares. If the environment directly below is harsh, the system calculates the location of the nearest safe zone, and the attitude control module 14 controls the attitude control thruster 141 to generate lateral force, corrects the landing point coordinates, and guides the pod to glide towards a safe area. Step Six: Landing Buffer and Post-Landing: Upon impact, the buffer airbag 1334 rapidly depressurizes and absorbs energy through the exhaust port 1333, reducing the peak impact. After landing and stabilization, the post-landing release module 16 detects the tension of the parachute lines. If there is a risk of wind dragging, the connection is automatically cut off, or the parachute can be manually released. If the landing point is in water, the floating airbag 172 automatically inflates, completing the entire emergency release process.

Claims

1. A detachable multi-rotor eVTOL pod system, characterized in that, include: The system includes a disengagement system (1) and a rotor system (3). The disengagement system (1) is detachably mounted in the central area of ​​the lower part of the main frame (2). The rotor system (3) is symmetrically arranged on the outer periphery of the main frame (2), and is fixed to the main frame (2) by a mechanical load-bearing structure. It is also electrically connected to the power battery and the avionics flight control system (4) through an electrical wiring harness. The detachment system (1) includes a pod module (11), a separation control module (12), a multi-mode deceleration landing module (13), an attitude control module (14), an environmental perception and obstacle avoidance module (15), a post-landing detachment module (16), and a water-floating airbag device (17). The pod module (11) is an independent cabin module that carries occupants or loads. The pod module (11) is detachably connected to the main frame (2) through the locking and releasing mechanism (123) of the separation control module (12). The separation control module (12) includes an emergency condition detection unit (121), a control unit (122), and a locking release mechanism (123). The emergency condition detection unit (121) collects real-time data on the flight status, power, flight control, and battery status of the aircraft. The control unit (122) has built-in fault tree analysis logic and adopts a triple-redundant fault-tolerant architecture to determine whether the preset emergency conditions are met. When the emergency conditions are met, it outputs an unlocking pulse signal to the locking release mechanism (123) and simultaneously cuts off the electrical connection interface (111) between the main frame (2) and the pod module (11). The locking release mechanism (123) is symmetrically arranged in three or four sets along the center of gravity of the pod to form a statically indeterminate constraint structure. The multi-mode deceleration landing module (13) is arranged at the top and bottom of the release system (1), including a main parachute (131), a backup parachute (132), a buffer airbag device (133), a parachute compartment (134), a parachute compartment cover (135), and an ejection mechanism (136), used to achieve step-by-step deceleration and landing buffer after emergency separation; the main parachute (131) is folded and stored in the internal cavity of the parachute compartment (134), and the bottom end of the parachute lines of the main parachute (131) is fixedly connected to the main load-bearing joint at the top of the release system (1); the top of the canopy of the main parachute (131) is connected to the guide parachute through a connecting strap, and the traction end of the guide parachute is fixedly connected to the traction strap inside the parachute compartment cover (135); the backup parachute (132) The system is configured in two sets, symmetrically arranged in the reserved compartments on the top of the release system (1) on both sides of the parachute compartment (134). The bottom end of the parachute rope of the backup parachute (132) is fixed to the independent load-bearing point on the top of the release system (1). The buffer airbag device (133) is arranged at the bottom and side of the pod module (11). The parachute compartment (134) is located in the middle of the top of the release system (1). The top opening of the parachute compartment (134) is fitted with a parachute compartment cover (135). The ejection mechanism (136) is fixed to the top side wall inside the parachute compartment (134). The actuating end of the ejection mechanism (136) is connected to the locking structure inside the parachute compartment cover (135). Under normal conditions, the parachute compartment cover (135) is locked at the opening of the parachute compartment (134). The attitude control module (14) is used to actively stabilize the attitude of the detachment system (1) after the pod separates and respond to trajectory correction commands; The environmental perception and obstacle avoidance module (15) is used to build an environmental model in real time, match the map database, plan the optimal descent trajectory, and output trajectory correction instructions to the attitude control module (14). The post-landing detachment module (16) is used to monitor the tension of the parachute lines and disconnect the main parachute (131) from the detachment system (1) when there is a risk of ground wind drag. The floating airbag device (17) is built into the lower side of the pod module (11) to provide buoyancy when landing in water. The pod module (11) includes an electrical connection interface (111), a cockpit frame (112), and a seat system (113). The electrical connection interface (111) is located at the docking surface between the top of the cockpit frame (112) and the main frame (2), and is electrically connected to the power supply bus and communication bus of the power battery and avionics flight control system (4). The cockpit frame (112) adopts a hybrid structure of carbon fiber composite material and aluminum alloy frame. The outer skin and key load-bearing components are laid and cured with T700 grade carbon fiber prepreg. The main body of the cockpit frame (112) is welded and formed by aviation grade 7075 aluminum alloy. The seat system (113) is integrally die-cast and fixed inside the cockpit frame (112) by aviation grade 7075 aluminum alloy. The seat system (113) is equipped with a safety strap (1131) and a seat (1132).

2. The detachable multi-rotor eVTOL pod system according to claim 1, characterized in that, The locking and releasing mechanism (123) includes a lock body (1231) made of high-strength alloy steel, a retractable locking pin (1232), a spring (1233), and an electromagnet (1234). The retractable locking pin (1232) is slidably assembled in the guide hole of the lock body (1231). The shear resistance safety factor of a single retractable locking pin (1232) is not less than 1.5, and the impact load it can withstand is not less than 10G. Under normal flight conditions, the retractable locking pin (1232) is locked in the pod lock hole by the pre-tightening force of the spring (1233) and the holding force of the electromagnet (1234). The overall tensile strength is greater than 20kN. When unlocking, the electromagnet (1234) generates a reverse magnetic field to overcome the pre-tightening force of the spring (1233) and retract the locking pin to complete the unlocking. At the same time, it triggers the mechanical switch to cut off the electrical connection interface (111).

3. The detachable multi-rotor eVTOL pod system according to claim 1, characterized in that, The data collected by the emergency condition detection unit (121) includes the three-axis angular velocity and linear acceleration of the inertial measurement unit, the altitude, airspeed and position information of the barometric altimeter and GPS / BeiDou, the speed, torque and temperature of the motor controller, the calculation redundancy and sensor health of the flight control system, and the voltage, current, temperature and smoke detection signal of the battery management system. The control unit (122) has preset emergency conditions including any one of the following: Power failure mode: The aircraft's vertical descent rate is greater than 5 m / s and all rotor speeds are below 20% of idle speed; Flight control failure mode: The deviation between flight control commands and attitude angle feedback exceeds the threshold and lasts for 2 seconds, or the flight control calculation margin is exhausted; Thermal runaway / fire mode: The battery temperature rise rate exceeds 5°C / s or the smoke concentration in the cabin triggers the alarm threshold; Structural failure mode: main frame (2) key connectors break or structural deformation exceeds preset threshold; The unlocking pulse signal output by the control unit (122) has a pulse width of 50ms to 100ms.

4. The multi-rotor eVTOL pod detachable system according to claim 1, characterized in that, The ejection mechanism (136) adopts a miniature explosive cord or spring ejection structure, which can open the parachute compartment cover (135) and pull out the guide parachute within 20ms; The main parachute (131) adopts a cross-shaped or ring sail structure. Under the condition of a detached system mass of 600kg, the canopy area is 80-100㎡, and the steady-state descent speed under standard atmospheric pressure is no more than 6m / s. The backup parachute (132) has a canopy area of ​​50% of that of the main parachute (131), and is independently arranged on both sides of the top of the cockpit and equipped with an independent pyrotechnic ejection mechanism for redundant deceleration when the main parachute fails, gets tangled or is damaged.

5. A detachable multi-rotor eVTOL pod system according to claim 1, characterized in that, The buffer airbag device (133) is made of aramid Kevlar coated sealing material. The buffer airbag device (133) has a built-in buffer airbag (1334), an exhaust port (1333), a height sensor (1331), and a first gas generator (1332). The height sensor (1331) triggers the first gas generator (1332) at a height of 30m to 50m above the ground. The airbag inflation time is less than 150ms, and the steady-state working pressure of the airbag is 0.2MPa to 0.35MPa. The buffer airbag device (133) actively releases pressure and absorbs energy through the exhaust port (1333), controlling the vertical impact load of the occupant to within 25G.

6. The detachable multi-rotor eVTOL pod system according to claim 1, characterized in that, The attitude control module (14) includes an attitude control thruster (141), an attitude sensor (1412), and an attitude control controller. The attitude control thruster (141) is arranged in an H-shape or cross shape around the separation system (1). It adopts a cold gas jet propulsion system (1411) or a micro solid rocket engine, with a single thrust of 100N to 300N and a specific impulse of not less than 50s. The attitude sensor (1412) includes a high-precision fiber optic gyroscope (14121) and a MEMS accelerometer (14122), with a sampling rate of not less than 200Hz; The attitude control controller adopts a robust PID or adaptive control algorithm, calculates the control torque based on attitude feedback and pulse width adjustment jet to suppress roll, pitch and yaw oscillations and ensure a vertical landing attitude; the attitude control controller receives trajectory correction instructions from the environmental perception and obstacle avoidance module (15), and forms a glide ratio through lateral thrust to achieve 100m to 200m lateral displacement obstacle avoidance.

7. A detachable multi-rotor eVTOL pod system according to claim 1, characterized in that, The environmental perception and obstacle avoidance module (15) includes a solid-state lidar (151), a millimeter-wave radar (152), a binocular vision sensor (153), and a processing unit (154). The solid-state lidar (151) has a horizontal field of view ≥120°, a vertical field of view ≥30°, and a detection range >100m, and is used to construct a three-dimensional terrain point cloud. The millimeter-wave radar (152) operates in the 77GHz band and is used for height measurement and detection of small obstacles such as cables. The binocular vision sensor (153) is configured with two sets. The lenses are symmetrically arranged on the front and left and right sides of the bottom of the pod module (11), and fixed to the mounting base at the bottom of the cockpit frame (112) by vibration damping brackets. The lenses face diagonally downwards, and the field of view covers the landing area directly below and in front of the cockpit. The processing unit (154) is an embedded computing platform that runs SLAM and path planning algorithms, integrates multi-sensor data, urban digital maps and safe landing area databases, and generates obstacle avoidance trajectory correction instructions when it detects obstacles or crowds below and sends them to the attitude control module (14).

8. A detachable multi-rotor eVTOL pod system according to claim 1, characterized in that, The post-landing release module (16) includes a tension sensor (161) and a mechanical release hook (162). The tension sensor (161) monitors the tension of the parachute lines of the main parachute (131) in real time. When the tension is greater than 50N for more than 3 seconds, it is determined to be a risk of ground wind drag. The control unit (122) triggers the electromagnetic release mechanism (1621) of the mechanical release hook (162) to disconnect the main parachute connection. The mechanical release hook (162) has both electric unlocking and manual emergency unlocking functions and is equipped with a manual unlocking handle.

9. A detachable multi-rotor eVTOL pod system according to claim 1, characterized in that, The floating airbag device (17) includes a water sensor (171), a floating airbag (172), and a second gas generator (173). After the water sensor (171) detects the bottom immersion signal, it triggers the second gas generator (173) to inflate rapidly. The floating airbag (172) forms a floating boat structure on both sides and the bottom of the cabin, and the total buoyancy is not less than 1.5 times the weight of the detached system (1).

10. The emergency detachment control method for a multi-rotor eVTOL pod detachable system as described in any one of claims 1-9, characterized in that, Includes the following steps: Step 1: Real-time monitoring and data fusion: After the system is powered on, the separation control module (12) collects IMU data, barometric altimeter data, GPS / BeiDou positioning data, motor controller feedback signals and battery management system status data in real time at a frequency of 100Hz; the control unit (122) performs Kalman filtering fusion on the multi-source data to estimate the current real state of the aircraft; Step Two: Fault Diagnosis and Decision Making The control unit (122) performs diagnosis based on preset fault judgment logic. When any preset emergency condition is met, it is determined to be an unrecoverable emergency state and triggers the escape procedure. Step 3: Separation and Initial Attitude Adjustment Within 10ms after the emergency conditions are met, the control unit (122) outputs an unlocking signal, the locking and releasing mechanism (123) operates synchronously, and the pod module (11) separates from the main frame (2) at a relative speed of 2m / s to 3m / s under the action of gravity and the thrust of the separation spring (1233); the attitude control module (14) is immediately activated to suppress the angular velocity disturbance at the moment of separation with the maximum thrust output, ensuring that the attitude angle of the separation system (1) is stable within the error range of ±5° before the parachute opens; Step 4: Execution of the multi-mode deceleration sequence: 0.5 to 1 second after separation, after the separation system (1) and the main frame (2) have a safe distance of more than 20 meters, the ejection mechanism (136) launches the guide parachute and pulls out the canopy of the main parachute (131); if the altitude is less than 50 meters at the time of separation, the control unit (122) directly triggers the buffer airbag (1334) to deploy in advance and activates the backup parachute (132) to assist in deceleration; during the descent, when the altitude above the ground drops to 50 meters, the buffer airbag (1334) is fully inflated; Step 5: Environmental Perception and Trajectory Guidance During the stable descent phase of the main parachute (131), the environmental perception and obstacle avoidance module (15) continuously scans the ground, generates a digital elevation model, and identifies obstacles and safe zones. If the environment directly below is harsh, the system calculates the location of the nearest safe zone, and the attitude control module (14) controls the attitude control thruster (141) to spray air, generating a lateral force to correct the landing point coordinates. Step Six: Landing Buffer and Post-processing Upon impact, the buffer airbag (1334) quickly releases pressure and absorbs energy through the exhaust port (1333) to reduce the peak impact. After landing and stabilizing, the landing detachment module (16) detects the tension of the parachute ropes. If there is a risk of wind dragging, the connection is automatically cut off. If the landing point is in water, the floating airbag (172) automatically inflates to complete the entire emergency detachment process.

Images