Multi-Mode Safety System for Vertical Takeoff and Landing Aircraft

Abstract

An aircraft safety system includes an impact energy reduction system, the impact energy reduction system including: an aircraft parachute, at least one rotor configured to autorotate, and an energy absorption system. An automatic control system uses data from speed and altitude sensors to selectively and sequentially deploy the impact energy reduction system in response to the detection of an emergency based on the aircraft speed and the portion of the altitude flight envelope in which the aircraft is operating.

Description

[0001] Cross - reference to related patent applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 619,422, filed on January 19, 2018, the entire content of which is incorporated herein by reference in its entirety. Background Art

[0003] Many vertical take - off and landing (VTOL) aircraft (such as helicopters) are equipped with rotors that can autorotate to serve as a safety system to address emergency scenarios involving engine power loss to the rotors. These autorotation - based safety systems rely on the functionality of the intact rotors and prevent safe operation in certain parts of the altitude - speed graph that may be required. Summary of the Invention

[0004] In one embodiment, a VTOL aircraft includes multiple safety systems, such as multiple rotors, each rotor configured to autorotate in the event that power is lost to the electric motor driving the rotor; a fuselage parachute that can be used to reduce the descent speed in an emergency scenario; and an airbag system that cushions an emergency landing beneath the fuselage of the aircraft. An automatic emergency control system monitors aircraft performance parameters to detect an emergency scenario. If an emergency scenario is detected, the automatic emergency control system is programmed to evaluate the specific emergency scenario, aircraft altitude, aircraft speed, and aircraft position relative to obstacles to selectively and / or sequentially deploy one or more of the multiple safety systems. The deployment of the multiple safety systems depends in part on the region of the altitude - speed graph in which the aircraft is operating when the emergency scenario is detected.

[0005] In various embodiments, the multiple safety systems include rotors configured for autorotation, a parachute, and energy - absorbing structures built into the fuselage and passenger seating positions.

[0006] In various embodiments, the automatic emergency control system includes programming with a threshold altitude above which, if an emergency scenario is detected, the automatic emergency control system deploys the parachute and below which it does not deploy the parachute.

[0007] In various embodiments, the automatic emergency control system uses data from sensors that measure the altitude of the aircraft above an impact location to control the deployment of an energy - absorbing system (such as an airbag beneath the fuselage).

[0008] In various embodiments, without the assistance of other safety systems such as airbags or autorotating rotors, the parachute is not sized to reduce the impact speed of the aircraft below a threshold speed for passenger safety. In these embodiments, the weight and size of the parachute can be minimized, making the aircraft more efficient.

[0009] In various embodiments, the programming of the automatic emergency control system includes pre-programmed regions of a height - speed graph, where the sequence and deployment of multiple safety systems depend on the height and speed of the aircraft when an emergency scenario is detected.

[0010] In various embodiments, the automatic emergency control system can be activated by a passenger of the aircraft who detects an emergency and interacts with the automatic emergency control system via a user interface.

[0011] In various embodiments, a rotor configured for autorotation includes a centralized control system rather than a cyclic control system.

[0012] In various embodiments, the automatic emergency control system provides an emergency signal to the pilot when an emergency scenario is detected. A time interval is provided such that the pilot can override the automatic deployment sequence of multiple safety systems. The time interval provided to the pilot depends on the region of the height - speed graph in which the aircraft is operating when the emergency scenario is detected, the position of the aircraft relative to an obstacle, and the nature of the detected emergency scenario.

[0013] In various embodiments, the pilot is located away from the aircraft and is provided with the emergency signal via wireless communication.

[0014] In various embodiments, the automatic emergency control system can be activated by a pilot operating the aircraft who remotely detects an emergency scenario and interacts with the automatic emergency control system via a user interface and wireless communication.

[0015] In various embodiments, the multiple safety systems include wings configured to provide aerodynamic lift to allow the aircraft to glide when sufficient airspeed is obtained.

[0016] In various embodiments, the threshold height for parachute deployment depends on the airspeed.

[0017] In various embodiments, the automatic emergency control system uses data regarding the aircraft's attitude to influence the deployment sequence and deployment timing of multiple safety systems.

[0018] In various embodiments, the threshold height is measured relative to the distance between the aircraft and an obstacle and terrain data included in a database.

[0019] In various embodiments, the automatic emergency control system receives data regarding the distance from an obstacle from sensors to evaluate the detection of an emergency scenario.

[0020] In various embodiments, the automatic emergency control system uses sensor data to predictively identify an emergency scenario involving a collision with an obstacle or terrain.

[0021] In various embodiments, an automatic emergency control system utilizes sensor data regarding an on-board fire to sequentially deploy a plurality of safety systems to minimize the time taken to safely place the aircraft on the ground. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a side view of an aircraft having a rotor configured to autorotate, a deployed parachute, and an energy absorption airbag deployed beneath the aircraft fuselage, according to an illustrative embodiment;

[0023] Figure 2 is an isometric view of an aircraft having a deployed parachute, a deployed energy absorption airbag located beneath the aircraft fuselage, and a rotor positioned not to autorotate, according to an exemplary embodiment;

[0024] Figure 3 is a side view of an aircraft having a rotor configured to autorotate and an energy absorption airbag deployed beneath the aircraft fuselage, according to an illustrative embodiment;

[0025] Figure 4 is a height - speed diagram of a helicopter;

[0026] Figure 5 is a height - speed diagram of an aircraft equipped with an automatic emergency control system, a parachute, an energy absorption system, and a rotor configured to autorotate, according to an illustrative embodiment;

[0027] Figure 6 is a flow chart showing the operation of an automatic emergency control system according to an illustrative embodiment; and

[0028] Figure 7 is a schematic diagram showing the components of an automatic emergency control system according to an illustrative embodiment. DETAILED DESCRIPTION

[0029] This document describes various embodiments of a multi - mode safety system for a vertical take - off and landing (VTOL) aircraft that utilizes one or more of an automatic emergency control system, a parachute, rotors with autorotation, and an energy absorption system. The systems, methods, and computer - readable media detailed in this specification utilize a combination of multiple safety systems and an automatic emergency control system to selectively deploy one or more of the multiple safety systems upon detection of an emergency scenario. The multi - mode safety system advantageously provides for operation of the VTOL aircraft within a large safety operation envelope on a height - speed diagram and also provides additional redundancy in the event of system failures. Advantageously, the safety operation envelope of the aircraft described herein is larger than that of other aircraft, such as helicopters, as will be discussed in detail below. This advantageously allows the aircraft described herein to operate more safely under various conditions of take - off, landing, and cruise, including various altitudes and speeds that allow the aircraft to operate safely during those various flight phases compared to other types of aircraft.

[0030] For example, there are regions of a helicopter's height - speed diagram where autorotation is not a viable alternative in the event of an engine failure because the altitude and response time available to the pilot may not be sufficient to safely enter autorotation. Autorotation is a flight state in which the rotor system rotates by the action of air moving upward through the rotor rather than by engine - driven control forces that drive the rotor. Autorotation allows energy to be selectively stored in the rotor by increasing its rotational inertia or released by pitching the rotor blades such that the rotational inertia is converted into thrust. Autorotation can also be used to adjust the aerodynamic drag of the rotor to control the rate of descent of an aircraft descending in a power - off manner. During autorotation, the collective control of the rotor is used to store or release energy and to adjust the drag. During autorotation, cyclic control is used to change the direction in which the aircraft travels. As described herein, in the event of an engine failure or other emergency, autorotation can be used to safely land the aircraft. For helicopters, it is necessary to safely avoid regions of the height - speed diagram where autorotation is not possible. This generally dictates using a flat departure profile for helicopters to avoid significant climb until sufficient forward airspeed is achieved. As further discussed below (e.g., see Figure 4 ), this can limit the departure and arrival flight profiles available for a VTOL helicopter that relies on autorotation to fly safely and can require the helicopter to fly closer to obstacles in the departure and arrival areas, creating a safety risk. The multi - mode safety system described herein is expected to minimize the unsafe regions of the height - speed diagram and protect the passengers of the VTOL aircraft from emergency scenarios other than engine failure that are caused by limited take - off and landing profiles (as further described below with respect to Figure 5 ).

[0031] Accordingly, a vertical takeoff and landing (VTOL) aircraft with rotors, as described herein, is desired to permit takeoff and landing from a small area without a runway. A helicopter has a height-velocity diagram (e.g., Figure 4 ) indicating regions of altitude and speed in which autorotation is not a viable means of safely landing the helicopter in the event of a power loss. This region of the height-velocity diagram is commonly referred to as the death curve. There are important low-speed and mid-altitude operating regions where a helicopter cannot autorotate and thus has no safe backup. Additionally, it is often desired to operate a VTOL aircraft in locations where obstacles may be present near the takeoff and landing positions, but a helicopter maintains a flat trajectory during takeoff or landing to ensure that it does not operate within the death curve. Thus, the goals of avoiding obstacles and remaining out of the death curve may work against each other, making many potential takeoff or landing positions unsafe for many helicopters and other VTOL aircraft.

[0032] Autorotation is also of limited use in emergency scenarios not involving power loss. If a rotor is damaged, a helicopter may have no safe way to land, and if the failure occurs more than a few feet above the ground, the probability of fatal injury to passengers is high.

[0033] Parachute systems for aircraft are known, but are difficult to use on a helicopter. Parachute systems for aircraft are typically deployed from the upper surface of the aircraft fuselage, and the cables connecting the parachute to the aircraft should be unobstructed for the parachute system to perform properly. However, a helicopter has rotor blades over substantially its entire body, making it difficult to place a parachute safely. A parachute system large enough to control the impact speed of the entire aircraft is also large and heavy, making it difficult to install in an aircraft where space and weight are both very precious.

[0034] A VTOL aircraft can have multiple rotors configured at many locations around a frame. While this produces the advantages of redundancy and control, it also reduces the total disk area of the rotors compared to a helicopter, such that in some cases, autorotation is not sufficient to safely reduce the impact energy below the threshold for survivability for all desired portions of the height-velocity diagram.

[0035] When compared to helicopters and other types of VTOL aircraft, the systems, methods, and computer-readable media described herein provide multiple benefits to enhance safety. Advantageously, the fatality curve of the aircraft is significantly reduced, enabling the ability to approach and depart at a steeper initial angle, providing increased obstacle clearance, and safely accessing an increased number of takeoff and landing positions. The described aircraft can also advantageously include redundancy from multiple safety systems, including autorotation systems, parachute systems, and energy absorption systems. In the event of rotor damage, the other safety systems can still safely bring the aircraft to the ground. Additionally, the use of an automatic emergency control system reduces the reaction time in deploying the safety systems. Faster deployment allows the safety systems to reduce the speed of the aircraft more quickly, thereby reducing the impact energy applied to the passenger compartment.

[0036] Figure 1 An aircraft 1000 is shown configured with a frame 100, a fuselage 102, a parachute 104, four rotors 106, and an energy absorption system 108. In an emergency event requiring a non-standard landing, a main control unit located within the aircraft 1000 can selectively deploy the parachute 104, initiate autorotation of the rotors 106, and / or deploy the energy absorption system 108 based on the altitude and / or airspeed of the aircraft 1000. An example main control unit 700 is described below and shown in Figure 7 FIG.

[0037] The main control unit can have some, all, and / or additional functions of the main control unit 700 described below, and the main control unit 700 is merely an exemplary embodiment of the main control unit. The rotors 106 can deliver thrust horizontally, vertically, or at an angle between horizontal and vertical. The direction of the thrust delivered by the rotors 106 depends on the orientation / position of the rotors 106 and / or how the rotors 106 are controlled by the main control unit. Since the rotors can generate thrust along an axis and can be configured for centralized and / or cyclic control, the rotors 106 can deliver thrust and torque in multiple directions, and the rotors 106 can deliver thrust and torque individually in different directions.

[0038] In Figure 1 FIG., the rotors 106 are configured to deliver thrust in a substantially vertical direction and are thus positioned to facilitate autorotation to arrest the descent of the aircraft 1000 if necessary. If the aircraft 1000 is airborne and experiences an emergency situation requiring a non-standard landing, the main control unit loaded on the aircraft 1000 evaluates various data to selectively deploy the parachute 104, deploy the energy absorption system 108, and / or initiate autorotation of the rotors 106. According to the various methods, systems, and computer-readable media described herein, including the method according to Figure 6 FIG., various aspects of the safety systems can be utilized and / or deployed.

[0039] The following discusses various sensors that can capture data evaluated by the main control unit to determine which safety systems to activate and / or deploy. In Figure 1 , the energy absorption system 108 includes a series of airbags that can be rapidly deployed from the underside of the fuselage 102 to cushion the impact of the aircraft 1000 with the ground or other objects. If an emergency occurs at a high enough altitude for deployment, the parachute 104 can be deployed, and if the rotor 106 is not already in that position, the rotor 106 can be positioned in the vertical thrust orientation. Both the parachute 104 and the rotor 106 reduce the descent rate of the aircraft 1000. When on-board sensors (such as the sensors described below with respect to Figure 7 ) identify that the aircraft 1000 is approaching impact with the ground, the energy absorption system 108 can be deployed so that it is fully deployed before hitting the ground. The parachute 104, the rotor 106, and the energy absorption system 108 are sized such that when the aircraft 1000 hits the ground, any two of the three systems can reduce the deceleration experienced by the passengers of the aircraft 1000 to a level that the passengers can withstand.

[0040] Figure 1 The energy absorption system 108 in is a deployable airbag. In some embodiments, the energy absorption system 108 can be a passive crumple zone or other shock-absorbing system. In embodiments where the energy absorption system 108 is configured as a passive system, there is no need for the main control unit to activate it before impact. These rotors 106 can be configured for both cyclic control and collective control to facilitate controlled flight during autorotation. Collective control allows the rotors 106 to store and release energy and also provides a variable amount of aerodynamic drag to the aircraft 1000 as it descends in an emergency scenario. Cyclic control allows the rotors 106 to provide directional control over the forces exerted by the rotors 106 on the airframe 100. In different embodiments, one, some, or all of these rotors 106 can be configured only for collective control and not for cyclic control. In the absence of rotors 106 configured for cyclic control, directional control of the aircraft 1000 can be achieved through differential collective control of the individual rotors 106.

[0041] Figure 2 An aircraft 2000 configured with an airframe 200, a fuselage 202, a parachute 204, eight rotors 206, and an energy absorption system 208 is shown. In an emergency event requiring a non-standard landing, the main control unit located within the aircraft 2000 can selectively deploy the parachute 204, initiate autorotation of the rotors 206, and / or deploy the energy absorption system 208 based on the altitude and / or airspeed of the aircraft 2000. The main control unit can be, for example, the main control unit 700 described below with reference to Figure 7 , and the main control unit 700 can performFigure 6 The method will also be described below. The rotor 206 can be positioned to deliver thrust horizontally, vertically, or at an angle between horizontal and vertical. In this illustration, the rotor 206 is configured to deliver thrust in a substantially horizontal direction and is thus positioned in a way that prevents autorotation. In the event of an emergency involving the loss of the ability to position the rotor 206 in a substantially vertical orientation for autorotation, the parachute 204 can be used to arrest the rate of descent of the aircraft 2000. If the main control unit detects an emergency and the rotor 206 cannot be reconfigured to achieve autorotation and the airspeed and altitude of the aircraft 2000 are such that parachute deployment is beneficial, the parachute 204 can be deployed to arrest the rate of descent of the aircraft 2000. When on-board sensors identify that the aircraft 2000 is approaching impact with the ground, the energy absorption system 208 can be fully deployed prior to impact with the ground. The combination of the parachute 204 that arrests the descent speed and the energy absorption system 208 that cushions the impact with the ground ensures that the passengers of the aircraft 2000 experience an acceptable level of deceleration during the impact of the aircraft 2000 with the ground.

[0042] Figure 3 An aircraft 3000 is shown configured with a frame 300, a fuselage 302, a rotor 306, an energy absorption system 308, and an undeployed parachute 304 contained within the fuselage 302. If an emergency occurs at an altitude and airspeed where it is not desirable or possible to deploy the parachute 304, the main control unit positions the rotor 306 in a substantially vertical orientation to facilitate autorotation. Autorotation of the rotor 306 reduces the rate of descent of the aircraft 3000 and facilitates control of the direction of the aircraft 3000 to allow selection of a suitable emergency landing location. The main control unit changes the cyclic and / or collective control of the rotor 306 to reduce the descent speed and position the aircraft 3000 at the desired emergency landing location. Immediately above the emergency landing location, the energy absorption system 308 can be deployed to reduce the impact deceleration of the aircraft 3000. The combination of the reduction in the descent speed from autorotation of the rotor 306 and the reduction in deceleration from the energy absorption system 308 reduces the deceleration experienced by the passengers of the aircraft 3000 during impact to a survivable level.

[0043] In various embodiments, the arrangement of the parachute and the configuration of the parachute are such that the deceleration caused by deploying the parachute is designed to be applied to the aircraft, including at the passenger seating position, in a manner that keeps the deceleration of the aircraft below a predetermined threshold. In this way, the deployment of the parachute does not decelerate the aircraft too quickly. That is, the maximum parachute deceleration applied to the aircraft (including at the passenger seating position) is below the deceleration threshold. This can be achieved using various parachute types and deployment methods. The energy absorption system is also designed and placed to impart to the aircraft, and primarily to the passenger seating position, a maximum energy absorption system deceleration. The energy absorption system can also be designed such that the maximum energy absorption deceleration is below a specific threshold. In various embodiments, the maximum energy absorption deceleration threshold can be substantially similar to or different from the threshold of the maximum parachute deceleration. Such a configuration and design provide maximum safety for any passenger. For example, if the aircraft is damaged (e.g., loses a wing), the parachute and the energy absorption system should still be attached to the passenger seating position and provide deceleration to the passenger seating position, rather than to some other part of the aircraft (e.g., a part of the aircraft that has separated from the passenger seating position). The energy absorption system also primarily provides deceleration to the passenger seating position. In this way, for example, in a collision or impact event, if the aircraft breaks apart, the deceleration of the other parts of the aircraft besides the passenger seating position does not need to be maintained below a threshold for survivability when the aircraft breaks apart. Thus, the safety systems are designed and configured to provide their maximum deceleration to the passenger safety position, rather than to some other part of the aircraft that may separate from the passenger seating position during impact. In various embodiments, the magnitude of the maximum parachute deceleration can be substantially similar to the magnitude of the maximum energy absorption system deceleration. In this way, if one of the parachute or the energy absorption system does not deploy or is not used in an emergency scenario for any reason (e.g., cannot be used based on the altitude and speed of the aircraft, cannot be operated or is damaged), the deployed / used system can still provide a deceleration magnitude similar to that of the non-deployed / used system. In other embodiments, the magnitude of the maximum parachute deceleration can be different from the magnitude of the maximum energy absorption system deceleration.

[0044] Figure 4An example of a height - speed diagram of a helicopter is shown. The unshaded region 400 represents combinations of airspeed and height where the helicopter can autorotate to the ground with a survivable impact deceleration. Region 402 represents combinations of airspeed and height where autorotation is not feasible because the combination of relatively low airspeed and height is insufficient to safely arrest the rate of descent of the helicopter in the event of loss of power to the rotor. The reaction time of the helicopter pilot is also a factor in determining the size of region 402. Region 404 represents combinations of airspeed and height where there is not enough time to safely initiate autorotation before impacting the ground if the rotor loses power. The flight profile 406 represents a typical departure or arrival of the helicopter. The helicopter must stay close to the ground as it accelerates to avoid being too high to land safely at low speed. Once the helicopter has accelerated sufficiently to store enough energy in its rotor, it can begin a safe climb. Thus, the helicopter utilizes substantially horizontal departure and arrival paths at the start and end of each flight, which can be challenging in locations where there are obstacles near the takeoff / landing position. Typically, the operation of the helicopter involves a safety compromise between avoiding region 402 and maintaining a clearance from obstacles near the helicopter. Alternatively, some locations may not be suitable for a safe takeoff or arrival in a helicopter.

[0045] Figure 5 A height - speed diagram 5000 of an aircraft using the multi - mode safety system, method, and computer - readable medium described herein is shown. The unshaded region 500 represents combinations of airspeed and height where the aircraft can safely return to the ground in an emergency excluding normal landing. The shaded region 502 represents combinations of airspeed and height where the multi - mode safety system cannot safely reduce the impact deceleration below a survivable threshold. Comparing Figure 5 the shaded region 502 and Figure 4 the shaded region 402, as a result of the safety system, method, and computer - readable medium described herein, region 502 advantageously provides a larger safe operating region (the unshaded region 500). The threshold line 512 represents combinations of airspeed and height above which a parachute can be deployed. Below the threshold line 512, the parachute can be only partially deployed before the aircraft impacts the ground. The threshold line 514 represents the height below which an energy - absorbing system can absorb enough impact energy to reduce the deceleration of the aircraft such that the impact is survivable.

[0046] The region between the threshold lines 512 and 514 is the region where autorotation of the rotor is used to first reduce the rate of descent before deploying the energy - absorbing system to ensure that the magnitude of the impact deceleration is below the threshold for survivability. In Figure 5In the example of, the energy absorption system is designed to have a threshold height represented by threshold line 512, which is substantially equal to the height for deploying a parachute above a threshold speed (i.e., threshold 512 and 514 are the same above a certain speed). Alternatively, in some embodiments, the substantially horizontal threshold line 514 can be completely below the threshold line 512 at any airspeed. Above the threshold line 512, either autorotation or the parachute can be sufficient to reduce the descent rate of the aircraft to a speed low enough for the energy absorption system to reduce the impact deceleration below the threshold for survivability. Alternatively, in the case of not using the energy absorption system, the combined reduction in the descent speed from both the parachute and autorotation in the region above the threshold line 512 can be sufficient to reduce the impact deceleration below the threshold for survivability. Below the threshold line 514, the energy absorption system is configured to cushion the impact of the aircraft without the assistance of autorotation or the parachute. In Figure 5 the region 502 of Figure 4 the reduction of the fatality curve in the region 402 of Figure 6 is due to the following circumstances: the energy absorption system pushes the lower boundary of this region upward with the threshold line 514, while the parachute pushes the upper boundary downward with the threshold line 512, and by using an automatic control system (such as the automatic control system described below regarding Figure 7 and Figure 4 ), moving the boundary to the left, which reduces the reaction time for deploying / utilizing the safety system. Therefore, when compared with the region 402, the implementation of the multi-mode safety features described herein significantly reduces the size of the unsafe region 502, and also provides a redundant way to safely bring the aircraft to the ground in some parts of the altitude-speed graph, while the helicopter according to Figure 5 completely relies on the function of the rotor system after an emergency situation has occurred. Figure 4 Only one of the altitude-speed graphs of the aircraft described herein is shown. According to various embodiments of the present description, other varying thresholds, airspeeds, and altitudes are possible and are expected. However, any aircraft according to the embodiments described herein can have an altitude-speed graph that has the significant advantages described herein compared to the altitude-speed graph of

[0047] Figure 5 It is also shown that an aircraft using a multi-mode safety system has a wider array of departure and arrival paths than a helicopter or other VTOL aircraft that does not use a multi-mode safety system. The steep departure path 506 shows an exemplary departure where the aircraft climbs steeply to avoid nearby obstacles while remaining out of the region 502 on the altitude-speed graph 5000. The intermediate departure path 508 is a less steep climb compared to the departure path 506, while the shallow departure path 510 is similar to as Figure 4The exemplary safe departure path of a helicopter. As described herein, the ability of the aircraft to depart from and / or reach an altitude-speed profile within the range between departure path 506 and departure path 510 provides significantly greater ability and flexibility for safe maneuvering around obstacles near the takeoff and landing positions, and allows the use of takeoff and landing positions that may be unsafe for a helicopter or other VTOL aircraft. Such various departure paths may not be possible to execute safely with an aircraft having Figure 4 the altitude-speed diagram. In addition to Figure 5 the three departure paths shown, according to various embodiments of the systems, methods, and computer-readable media described herein, other departure paths are possible and expected.

[0048] Figure 6 is a flowchart of an aircraft emergency control method 6000 according to an illustrative embodiment. In alternative embodiments, fewer, additional, and / or different operations may be performed. Moreover, the use of the flowchart does not imply a limitation on the order of the operations performed. Method 6000 may be implemented in an aircraft as described herein. For example, an aircraft such as Figure 1 aircraft 1000, Figure 2 aircraft 2000, or Figure 3 aircraft 3000 may have a main control unit, such as the main control unit 700 discussed below with respect to Figure 7 , which implements aspects of a multimode safety system according to the various methods, systems, and computer-readable media described herein. Method 6000 illustrates one possible way in which a multimode safety system may be implemented. A computer-readable medium according to method 6000 may be stored in a memory and executed by a processor such as the main control unit 700 discussed below.

[0049] At block 605, the system receives sensor and interface data. For example, the sensor data may include airspeed, altitude, proximity, pressure, temperature, power loss, fire, fault indication, fuel status, or any other sensor data. The system also monitors the interface data. The aircraft may, for example, have a graphical user interface (GUI) that allows a passenger, pilot, or more generally a user of the aircraft to input certain data to be monitored. The user may be on the aircraft or may be away from the aircraft. Similarly, an interface such as a GUI may be on the aircraft or may be away from the aircraft. The data may be input through a GUI such as a touch screen, or through other inputs such as buttons, switches, etc. Thus, the data provided to the system may be measurement data from sensors or manual input data from the user. Thus, the system can automatically or manually detect an emergency situation based on the sensor data or through the input of the user.

[0050] At block 610, the system evaluates the sensor data and compares the data with an internal database. The internal database includes information regarding the altitude - speed profile of the aircraft. The altitude - speed profile of the aircraft can be the altitude - speed profile 5000 discussed above with respect to Figure 5 the altitude - speed profile discussed above. In other embodiments, different aircraft can have different altitude - speed profiles as the altitude - speed profile of an aircraft is specific to the precise parameters of the aircraft and the capabilities of the various safety systems installed thereon. Further at block 610, the system monitors the terrain and / or obstacle positions, such as buildings, ground, water, other aircraft, etc. Further at block 610, the system monitors the information in the database indicating an emergency. The database can indicate which parameters, sensor data, etc. indicate an emergency. Other aspects monitored by the system at block 610 (such as monitoring of terrain / obstacles and sensor data and interface data) help determine whether an emergency exists.

[0051] At block 615, the system determines whether an emergency exists based on the various data evaluated and monitored at block 610. If no emergency exists, the system returns to block 605 to continue receiving sensor and interface data at block 605 and continue evaluating the data at block 610. At block 615, the system can determine the existence of an emergency based on input from the user. The system can also determine the existence of an emergency based on sensor data. For example, the sensors can indicate that the aircraft has no fuel and / or battery power. In one example, the sensors can indicate that there is a fire on or inside the aircraft. In one example, the sensors can indicate that certain equipment of the aircraft, such as rotors, motors, or aerodynamic control surfaces, has lost functionality and / or has been damaged. Other aspects or parameters of the aircraft can also be monitored to detect and determine an emergency scenario. For example, various types of sensors can be used to monitor one or more engines, motors, actuators, etc. of the aircraft. For example, the system can detect whether one or more engines powering one or more rotors are not operating properly, whether the cyclic and / or collective control of one or more rotors is not operating properly, whether the systems of the wing and / or nacelle of the rotating rotor are not operating properly, etc. Any one or a combination of these factors can be used by the system to determine the existence of an emergency. In various embodiments, information regarding the status of these or other various systems of the aircraft can also be used to determine which safety systems to deploy as described herein. For example, if the system for the wing and / or nacelle of the rotating rotor is not operating properly, the emergency system can determine that autorotation cannot be achieved based on the current position of the rotor. Thus, the sensors of the aircraft can also monitor various aspects of the safety systems. If an aspect of the safety system is unavailable, an emergency can be triggered and / or this can affect how other aspects of the system are deployed and / or utilized.

[0052] At block 620, the system evaluates sensor, interface, and database data to control emergency system deployment as described herein. In operations not shown in method 6000, a user is able to override an emergency scenario via the interface. For example, an emergency situation can be detected, a warning sent to the interface, and the user can have a threshold amount of time to input an override signal into the interface. In other embodiments, the user may not be able to override the emergency detection and subsequent actions taken by the system. In some embodiments, the option to override an emergency scenario is only presented to the user in certain types of emergency scenarios detected by the system. When evaluating sensor, interface, and database data to control emergency system deployment, each of blocks 625, 635, and 645 is performed to continuously monitor the aircraft, sensor data, interface data, and database data to ensure that aspects of the multimode safety system are properly deployed and / or utilized to protect the passengers / users of the aircraft.

[0053] At block 625, the system determines whether the ground is close enough to deploy an energy absorption system. Proximity sensor data can be used to determine how close the aircraft is to the ground. Airspeed sensor data can be used to determine the speed at which the aircraft is traveling. Proximity and airspeed data can be used to determine when the aircraft will impact the ground and when the energy absorption system should be deployed (typically just prior to impact with the ground). In one embodiment, proximity data can also be monitored over time to estimate when the aircraft will impact the ground. In some embodiments, when an emergency scenario has been determined, the system can deploy the energy absorption system within a specific proximity to the ground regardless of the speed or acceleration at which the aircraft is moving towards the ground. That is, deployment of the energy absorption system can be based only on the immediate data from the proximity sensor. In an alternative embodiment, the energy absorption system can be deployed based on altitude sensor / data alone or in combination with other sensor data. If the system determines at block 625 that the ground is close enough to deploy the energy absorption system, the system does so at block 630 and then returns to block 620. If not, the system returns directly to block 620 and continues to perform blocks 625, 635, and 645 to monitor when and how aspects of the multimode safety system are deployed and / or utilized.

[0054] At block 635, the system determines whether the altitude above the terrain / ground and the airspeed of the aircraft are sufficient to deploy a parachute. For example, referring to an aircraft with a Figure 5 height - speed graph 5000, when the aircraft is above threshold 512, the aircraft can have an appropriate altitude and airspeed to deploy a parachute. In other words, as Figure 5As shown, the parachute can be deployed based on a threshold height, where the threshold height depends on the airspeed of the aircraft. In another way, according to this embodiment, the height at which the parachute can be deployed varies according to the airspeed of the aircraft. If the system determines at block 635 that the height and airspeed of the aircraft are sufficient to deploy the parachute, the system deploys the parachute at block 640 and returns to block 620. If it is not determined that the aircraft is at an appropriate height and airspeed to deploy the parachute, the system returns to block 620 and does not deploy the parachute.

[0055] At block 645, the system determines whether the rotor is functioning to control autorotation. If the rotor of the aircraft is not functioning to control autorotation, the system returns to block 620. Although not shown here, the system can also take measures to allow the rotor to have an autorotation function. For example, if the rotor is positioned to provide thrust substantially in the (relative to the ground) horizontal direction as Figure 2 shown, the system can rotate the wing and / or rotor such that autorotation is available (if rotation of the wing and / or rotor is possible). Similarly, if the rotor is in a position to provide thrust between substantially horizontal and vertical directions, the rotor and / or wing can be adjusted to provide better functionality regarding autorotation.

[0056] If the system determines at block 645 that the rotor is functioning to control autorotation, the system proceeds to block 650, where the system determines whether the height above the terrain is low enough for the aircraft to flare. If the height above the terrain determined at block 650 is low enough, the system flares the aircraft using the autorotation of the rotor at block 660 and reduces the impact speed. If the height above the terrain determined at block 650 is not low enough for flaring, at block 655, the system uses autorotation to adjust the descent rate of the aircraft and / or maneuver the aircraft. For example, it may be desirable to maneuver the aircraft to a position more suitable for a non-standard / emergency landing than the current position of the aircraft. In addition to using autorotation to maneuver the aircraft and / or adjust the descent, the system returns to block 620 to continue evaluating data related to the aircraft and potentially deploy various aspects of the multimode safety system according to blocks 625, 635, and 645.

[0057] Figure 7An aircraft emergency control system 7000 is shown, which includes a main control unit 700 that receives data from an air data system 702, a proximity sensor 704, a human-machine interface 706, a terrain and obstacle database 708, and internal sensors 710. The air data system 702 may include sensors for airspeed and altitude. The proximity sensor 704 may include lidar, radar, and / or vision systems. The human-machine interface 706 may include a display of emergency scenarios and a graphical user interface and / or buttons / keys for user input to the main control unit 700. The terrain and obstacle database 708 may include data on terrain altitude, obstacle locations and heights, and water locations. The internal sensors 710 may include sensors for power loss, fire, system failures, structural failures, and fuel status. The main control unit 700 utilizes the available data to control the deployment of autorotation by interacting with the aircraft autopilot 720. The aircraft autopilot 720 controls the rotor 722 by commanding the periodic and collective control of the rotor to achieve the desired control of the aircraft commanded by the main control unit 700. The main control unit 700 also interacts with a parachute system 730 and may control the deployment of the parachute. The main control unit 700 also interacts with an energy absorption system 740 and may command the deployment of the energy absorption system 740. When an emergency situation is detected based on the sensors / inputs 702, 704, 706, 708, and 710, the parachute system 730, the rotor 722, and the energy absorption system 740 are controlled by the main control unit 700. Thus, the emergency system of the aircraft can be controlled using the Figure 7 aircraft emergency control system 7000 described herein.

[0058] The aircraft control system 7000 may include a memory on which a computer-readable medium is stored. Such a computer-readable medium may be computer-executable code that is executed by the main control unit 700 to implement the various methods and systems described herein, including the various aspects of the multi-mode safety described herein. The main control unit 700 may be, for example, a computer processor. The instructions stored in the memory and executable by the processor may be implemented to perform various methods, such as those associated with Figure 6A method associated with the aircraft emergency control method 6000 shown and described above. In various embodiments, aspects of the aircraft emergency control system 7000 (such as the main control unit 700, the human-machine interface 706, the terrain and obstacle database 708, and / or the aircraft autopilot 720) may be located in the aircraft and / or may be entirely or partially remote from the aircraft. Some components / aspects may also be redundant. For example, instances of the main control unit 700 may be present in the aircraft and remotely, such that the aircraft itself may determine an emergency scenario, but an external system may also determine the emergency scenario. Thus, some or all of the control of the emergency system may be remotely controlled, such as at a remote flight control center.

[0059] In an illustrative embodiment, any operation described herein may be at least partially implemented as computer-readable instructions stored on a computer-readable medium or memory. When the processor executes the computer-readable instructions, the computer-readable instructions may cause the computing device to perform the operation.

[0060] The foregoing description of the illustrative embodiments has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the precise forms disclosed, and modifications and variations are possible in light of the above teachings or in accordance with the practice of the disclosed embodiments. The scope of the invention is intended to be defined by the appended claims and their equivalents.

Claims

1. An aircraft having a safety system, the aircraft comprising: A fuselage; A passenger seating position located within the fuselage; A rotor configured to autorotate; A parachute attached to the aircraft; An energy absorption system configured to reduce the impact acceleration applied to the passenger seating position when the fuselage impacts the ground in a substantially horizontal attitude; and An automatic emergency control system configured to: Determine the altitude of the aircraft and the airspeed of the aircraft; Detect an emergency; And In response to the detection of the emergency: When the aircraft is above a threshold altitude at the time of detection of the emergency, deploy the parachute and rotor autorotation to control the speed of the fuselage at or below a threshold speed, wherein the threshold altitude depends on the airspeed of the aircraft; And When the aircraft is at or below the threshold altitude at the time of detection of the emergency, deploy rotor autorotation without deploying the parachute to control the speed of the fuselage at or below the threshold speed, Wherein the threshold speed is determined such that the deployment of rotor autorotation alone or the deployment of both rotor autorotation and the parachute in combination with the deployment of the energy absorption system maintains the impact acceleration applied to the passenger seating position during impact below a threshold acceleration.

2. The aircraft according to claim 1, wherein, The parachute is sized such that when the parachute is deployed, the parachute alone is not sufficient to maintain the speed of the fuselage below the threshold speed.

3. The aircraft according to claim 1, Wherein the energy absorption system is further configured to deploy from below the fuselage.

4. The aircraft according to claim 1, wherein, The automatic emergency control system includes instructions stored in a memory and executable by a processor, the instructions configured to cause the processor to control the conditional deployment of rotor autorotation, the parachute, and / or the energy absorption system.

5. The aircraft according to claim 1, wherein within a predetermined range of the operating airspeed and altitude parameters of the aircraft, the parachute is not sized to reduce the impact acceleration of the passenger seating position below the threshold acceleration without being deployed in combination with at least one of the energy absorption system or rotor autorotation.

6. The aircraft according to claim 1, wherein, Within a predetermined range of the operating airspeed and altitude parameters of the aircraft, rotor autorotation is not sufficient to reduce the impact acceleration of the passenger seating position below the threshold acceleration without being deployed in combination with at least one of the energy absorption system or the parachute.

7. The aircraft according to claim 1, wherein, Within the operating range of the operating airspeed and altitude parameters of the aircraft, only two of the three safety systems including rotor autorotation, the parachute, and the energy absorption system must be operable to reduce the impact acceleration of the passenger seating position below the threshold acceleration.

8. The aircraft according to claim 4, wherein, The instructions are further configured to cause the processor of the automatic emergency control system to access a database to selectively determine a deployment order of at least two of autorotation of the rotor, the parachute, and / or the energy absorption system based at least in part on a relative position of the aircraft with respect to terrain or an obstacle, and store information about the terrain or the obstacle in the database, where the database includes at least one of a terrain position, a terrain altitude, a terrain type, an obstacle position, an obstacle altitude, or an obstacle type.

9. The aircraft according to claim 4, wherein, The instructions are also configured to cause the processor of the automatic emergency control system to send a notification to a user interface when an emergency scenario is detected.

10. The aircraft according to claim 9, wherein the instructions are further configured to cause the processor of the automatic emergency control system to receive an emergency override signal from the user interface within a predetermined amount of time starting from when the emergency scenario is detected or the notification is sent, where the emergency override signal is configured to override a deployment of one or more of the parachute, autorotation of the rotor, or the energy absorption system.

11. The aircraft according to claim 9, wherein the instructions are further configured to cause the processor of the automatic emergency control system to deploy one or more of the parachute, autorotation of the rotor, or the energy absorption system when no emergency override signal is received within a predetermined amount of time starting from when the emergency scenario is detected or the notification is sent.

12. The aircraft according to claim 9, wherein the user interface is remotely located outside the aircraft and the notification is made via wireless communication.

13. The aircraft according to claim 1, wherein the aircraft further includes a plurality of rotors, a portion of an upper side of the fuselage is not blocked by the plurality of rotors, and a deployment system of the parachute is located in the unblocked portion of the upper side of the fuselage.

14. The aircraft according to claim 1, wherein, The parachute is configured to impart a maximum parachute deceleration to the passenger seating position, and further, wherein the energy absorption system is configured to impart a maximum energy absorption system deceleration to the passenger seating position, and wherein an amplitude of the maximum parachute deceleration is substantially similar to an amplitude of the maximum energy absorption system deceleration.

15. The aircraft according to claim 1, wherein the aircraft further includes a plurality of rotors, and the rotors are positioned such that autorotation of the rotors can occur when the parachute is in a deployed configuration.

16. The aircraft according to claim 1, wherein, The threshold acceleration is a threshold acceleration for survivability.

17. A method of controlling an aircraft having a safety system, the method comprising: determining, by a processor, an altitude of the aircraft and an airspeed of the aircraft; detecting, by the processor, an emergency of the aircraft, where the aircraft includes: a fuselage; a passenger seating position located within the fuselage; a rotor configured for autorotation; a parachute attached to the aircraft; and an energy absorption system configured to reduce an impact acceleration applied to the passenger seating position when the fuselage impacts the ground in a substantially horizontal attitude; and In response to the detection of the emergency: When the aircraft is above a threshold altitude upon detection of the emergency, deploy the parachute and autorotate the rotors to control the speed of the fuselage at or below a threshold speed, where the threshold altitude depends on the airspeed of the aircraft; and When the aircraft is at or below the threshold altitude upon detection of the emergency, deploy autorotation of the rotors without deploying the parachute to control the speed of the fuselage at or below the threshold speed, wherein the threshold speed is determined such that the deployment of autorotation of the rotors alone or the deployment of both autorotation of the rotors and the parachute in combination with the deployment of the energy absorption system maintains the impact acceleration applied to the passenger seating position during impact at below a threshold acceleration.

18. The method according to claim 17, wherein, The threshold acceleration is a threshold acceleration for survivability.

19. A non-transitory computer-readable medium having instructions stored thereon that, when executed by a computing device, cause the computing device to perform operations, wherein the instructions include: Instructions for a processor to determine the altitude of the aircraft and the airspeed of the aircraft; Instructions for the processor to detect an emergency of the aircraft, wherein the aircraft includes: A fuselage; A passenger seating position located within the fuselage; Rotors configured for autorotation; A parachute attached to the aircraft; and An energy absorption system configured to reduce the impact acceleration applied to the passenger seating position when the fuselage impacts the ground in a substantially horizontal attitude; and Instructions to perform the following operations in response to the detection of the emergency: When the aircraft is above a threshold altitude upon detection of the emergency, deploy the parachute and autorotate the rotors to control the speed of the fuselage at or below a threshold speed, where the threshold altitude depends on the airspeed of the aircraft; and When the aircraft is at or below the threshold altitude upon detection of the emergency, deploy autorotation of the rotors without deploying the parachute to control the speed of the fuselage at or below the threshold speed, wherein the threshold speed is determined such that the deployment of autorotation of the rotors alone or the deployment of both autorotation of the rotors and the parachute in combination with the deployment of the energy absorption system maintains the impact acceleration applied to the passenger seating position during impact at below a threshold acceleration.

20. The non-transitory computer-readable medium according to claim 19, wherein, The threshold acceleration is a threshold acceleration for survivability.

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