Patent ID: 12252260

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides novel safety apparatus for an aerial vehicle, whether a manned aerial vehicle or an unmanned aerial vehicle (UAV), which mitigates damage to bystanders and to neighboring aerial vehicles when the given aerial vehicle is experiencing an unanticipated failure. Although the following description relates to a UAV, it will be appreciated that the invention is likewise applicable to a manned aerial vehicle mutatis mutandis.

The safety apparatus comprises a sensor-based, on-board failure detection unit that is capable of identifying a critical UAV failure and various devices, such as parachute deployment apparatus and communication equipment for transmitting distress or alarm signals, which are automatically activated in response to identification of the critical failure. The safety apparatus is operational independently of the conventional flight dependent systems for the UAV, one or more of which may be malfunctioned due to the critical failure.

The parachute deployment apparatus comprises propellable projectiles for rapidly deploying a parachute within a time period significantly less than a second, and even as less as 0.3 sec, to ensure a life saving parachute deployment operation when located at a relatively low altitude such as 20 m above ground level.

The safety apparatus is usable in conjunction with various types of UAV, such as a fixed-wing aircraft for carrying a relatively heavy payload while lift is generated by the forward airspeed provided by a propeller driven by an electric motor, rotorcraft which generates lift by a set of rotors, including multirotor aircraft for example of four, six or eight rotors by which aircraft motion is controlled by varying the relative speed of each rotor, vertical take-off and landing (VTOL) vehicles, a helicopter comprising variable pitch rotors, and a gyrocopter that uses an unpowered rotor in free autorotation to develop lift while forward thrust is provided by an engine-driven propeller. Each of these rotors and propellers may be referred to as a “lift generator”, and the motor or engine configured to drive the lift generator may be referred to as “drive means”.

In other embodiments, the safety apparatus is secured to a fixed or movable platform to mitigate damage to property or to nearby humans.

FIG.1illustrates apparatus10, according to one embodiment of the present invention. Apparatus10comprises a substantially vertically disposed manifold3from which obliquely and upwardly extend a plurality of hollow tubes8, e.g. three or four, in communication with the interior4of manifold3via a corresponding aperture16formed in the inner surface of the manifold. A rod11terminating with a larger surface projectile13, e.g. with an arrow-shaped or tear-shaped head, is inserted into a corresponding tube8. A draw cord is attached between each projectile13and a corresponding peripheral portion of the parachute canopy. These draw cords are in addition to the suspension lines that connect the canopy to the object to be parachuted, as well known to those skilled in the art.

To prevent tearing, the canopy may be made of reinforced netting, for example Nylon 66 ripstop fabric. The undeployed parachute canopy is folded on top of manifold3, and is retained in a chamber illustrated inFIG.13.

Manifold3may have a rectangular vertical cross section as shown, or may be configured in other ways as well.

Tubes8are all oriented at the same angle, e.g. 30 degrees relative to a vertical plane, to ensure uniform opening of the parachute. An intermediate tube14of shorter length and oriented at a larger angle than the rod receiving tubes8may extend from manifold3to a corresponding tube8.

As shown in the exploded version of apparatus10inFIG.2, a single, small sized pressure vessel47constituting a micro gas generator (MGG) is threadedly engageable, by external threading42formed in a bottom region of cylinder41which defines the vessel, with internal threading formed within cylinder24integral with, and extending downwardly from, manifold3. Projectile13is shown to be integrally formed with a corresponding rod11. All components of apparatus10that are exposed to the generated gas, including manifold3, tubes8, rods11and projectiles13are made of heat resistant material. By employing a single MGG that efficiently deploys a parachute, the weight and therefore the cost of the apparatus are significantly reduced with respect to the prior art.

As shown inFIG.3, an aperture49is formed in an upper region of vessel47, e.g. in its circumferential wall, through which the generated gas is dischargeable into the interior of manifold3, when the vessel is fully received within the interior of the manifold, and then through the interior of each tube8, in order to cause the projectiles to be propelled a predetermined distance.

Alternatively, pressure vessel47may be positioned on top of the manifold and the aperture through which the generated gas is dischargeable may be formed in a lower region of the vessel.

Referring now toFIG.4, vessel47contains a solid propellant48consisting of materials that normally do not chemically react with each other and a pyrotechnic device51for initiating a reaction with propellant48.

The vessel47is of sufficiently small dimensions, e.g. having a diameter of 2 cm and a length of 7 cm, in order to be compactly retained in the manifold cylinder when not in use, yet is highly efficient in terms of its gas generating capability. A vessel47is replaceable upon conclusion of a parachute deployment operation.

Pyrotechnic device51may be activated by an electrical current source54for heating a conductor of the device above the ignition temperature of a combustible material in contact therewith. Ignition of the combustible material initiates the MGG, causing a rapid chemical reaction involving propellant48that generates a large volume of pressurized gas G, e.g. nitrogen, within the manifold interior. The materials of propellant48and the current and voltage supplied by electrical current source54may be selected so as cause a highly exothermic reaction.

In one implementation as illustrated inFIG.5, a user desiring to deploy a parachute according to the teachings of the present invention triggers the MGG in step31by electrical or mechanical means well known to those skilled in the art, which need not be described for purposes of brevity. As a result of the triggering operation, the pyrotechnic device becomes activated in step32, causing the constituent components of the propellant to react and to generate energy intensive gas. The generated gas simultaneously flows through each tube extending from the manifold in step33, applying an explosive force onto a corresponding projectile. The explosive force is converted into momentum, and each projectile is therefore propelled in a different direction for a predetermined distance in step34. This distance, which is generally the sum of the length of the draw cord and the canopy radius, is reliably achieved by providing a sufficient dose of combustible material and a sufficient amount of activation current, to cause the parachute to be deployed in step35by being expanded to the desired canopy diameter.

After being deployed, ambient air is received in the interior of the parachute, causing the latter to be retained in a buoyancy generating inflated condition. While the canopy is fully expanded, the projectiles remain attached thereto by a corresponding draw cord after having transferring their kinetic energy to the canopy to urge the latter to an expanded condition. The weight of each projectile, e.g. 23 gm, is negligible with respect to the buoyancy force generated by the parachute, and therefore will not significantly impact the buoyancy of the parachute. A parachuting operation is then commenced in step36.

In one embodiment, the projectile head is sealed within the inclined tube. In this fashion, the gas pressure within the tube can be increased, to allow the projectile to be propelled a further distance.

It will be appreciated that the various components that are exposed to the generated gas need not be made of heat resistant material when other types of gas such as carbon dioxide or nitrogen are employed.

FIGS.8-13illustrate another embodiment of the invention whereby the pressurized gas is generated by means of a spring loaded puncturing mechanism for generating pressurized gas, e.g. carbon dioxide, on demand upon puncturing a vessel containing a compressed or liquid gas.

FIG.8illustrates an assembled, ready to trigger parachute deploying apparatus80, which comprises manifold83having three inclined tubes8into each of which a corresponding arrow-headed projectile13is inserted, compressed gas vessel87releasably engaged with the top of manifold83, hollow spring housing89threadedly engageable with manifold83and in which is housed a spring and hammer for driving the puncturing mechanism, an outer tubular rotatable element91for encircling spring housing89and for selectively releasing a vertically displaceable hammer, and a bottom circular plate95positioned above larger circular plate84and below rotatable element91which is formed with a groove96for limiting the angular displacement of element91. At the mouth88of vessel87is formed a pierceable metallic diaphragm, generally near the threading of the vessel.

FIG.9schematically illustrates apparatus80when the spring housing is removed, showing hammer94positioned internally to rotatable element91and which is vertically displaceable, on release of the spring force provided within the spring housing, at a sufficiently high speed to upwardly drive the bottom of pointed striking pin81so as to pierce the diaphragm and cause the liquid gas to change state in order to suitably propel the projectiles. Striking pin81is normally positioned within manifold83below the diaphragm of the gas generating vessel.

FIG.10illustrates striking pin81after it has been upwardly driven. As shown, spring housing89is formed with two opposed vertical grooves97through each of which a corresponding arm of the hammer is able to pass.

FIG.11illustrates the means for selectively releasing hammer94. Rotatable element91has two opposed restrainers92circumferentially extending a limited distance along its inner face86, adjacent to its rim85. After the spring within the spring housing is tensed by an external tensioning device, as well known to those skilled in the art, hammer94is positioned such that the two protrusions99terminating at the end of a corresponding arm98which radially extends from the main central portion of the hammer are below a corresponding restrainer92and prevented from moving. When rotatable element91is circumferentially shifted, protrusions99become unrestrained, allowing hammer94to be vertically displaced.

FIG.12illustrates the disengaging unit, for initiating rotation of rotatable element91and the resulting forceful vertical displacement of the hammer. External spring112is attached at one end to bottom plate84and at the other end to rod108horizontally extending from rotatable element91, for example from block111attached to the outer wall of rotatable element91. After upper plate95is rotated to extend external spring112, vertically oriented pin103in releasable engagement with ring107(FIG.9) protruding outwardly from rotatable element91is inserted within an aperture formed in plate95, to secure rotatable element91while external spring112is tensed. Electrical motor105, e.g. a servomotor, rotatably drives cam109, when activated, to disengage pin103from plate95and to enable angular displacement of rotatable element91upon release of the spring force applied by external spring112.

FIG.13illustrates circular chamber122in which the undeployed parachute is stored. Chamber122has a discontinuous wall, which is provided with a plurality of circumferentially spaced U-shaped portions126extending vertically along the entire height of chamber122. Manifold83is positioned within the interior of chamber122, internally to each of the U-shaped portions126. To facilitate positioning of each projectile rod8within the interior of a corresponding U-shaped portion126in preparation to be propelled, the internal wall of each U-shaped portion126facing manifold83may be formed with a bottom groove. Chamber122is connected to the object to be parachuted.

Alternatively, the puncturing mechanism is also operable when the compressed gas vessel is releasably engaged with the bottom of the manifold.

A parachute deployment operation may be initiated by a user who is entrapped within a skyscraper during a catastrophic event. As no other means of rescue is anticipated, the user mounts a harness to which is attached the apparatus of the present invention onto his upper torso. After the user jumps from an upper story, the MGG is triggered in midair while the projectiles are propelled behind, and rearwardly from, the user, allowing the parachute to be deployed within 0.3 sec following the triggering action due to the fast acting apparatus. This parachute deploying duration corresponds to a falling distance of only approximately 2 m. By virtue of the fast acting apparatus, a user will be assured of being protected even when jumping from a relatively low altitude such as 20 m above ground level, i.e. at a low story of a building. After descending to safety, the used vessel that generated the projectile propelling gas is replaced and the deployed parachute is folded, in anticipation of another parachute deployment operation, if necessary.

It will be appreciated that a parachute deployment operation may be initiated in response to many other scenarios that require an object to be parachuted.

Alternatively, the parachute deploying apparatus may be provided on light aviation aircraft, including an unmanned aerial vehicle (UAV) and Personal Aerial Vehicle (PAV), regardless of shape, construction material and geometry.

In this embodiment, as schematically illustrated inFIGS.6and7A-B, safety apparatus15is retained within a chamber17attached to a support element14of the aircraft and has a detachable lid18. Safety apparatus15may comprise expandable parachute assembly20shown in a folded condition, parachute deploying apparatus10for instantly deploying parachute assembly20, e.g. made of Kevlar®, upon demand, a wireless communication unit27for remotely controlling operation of the safety apparatus, and a rotor deactivation unit29synchronized with parachute deploying apparatus10for preventing damage to the parachute when being expanded. Lid18becomes detached from chamber17when the parachute becomes sufficiently expanded so as to apply a force onto the lid.

An operator interacting with a remote flight controller may transmit a wireless duress indicating signal W to the transceiver of communication unit27upon detection that the UAV has been subjected to conditions of duress requiring deployment of the parachute. After receiving signal W, communication unit27transmits a deactivation signal D for operating rotor deactivation unit29, which is in electrical communication with a controller39of the rotor drive means. Deactivation of the rotors will ensure that the expanding parachute will not become entangled with the rotating blades. Simultaneously with the transmission of signal D, or shortly thereafter, communication unit27transmits an initiation signal I to current source54, which in turn generates a suitable current C for activating pyrotechnic device51. Current C flows to the pyrotechnic device51of vessel47via contacts61extending from the bottom end of the vessel. Activation of pyrotechnic device51causes the constituent components of propellant48to react and to generate gas G, which is discharged into manifold3in order to propel the plurality of projectiles.

The conditions of duress may be detected remotely by the operator in conjunction with a remote processor, or, alternatively, may be determined by an on-board failure detection unit135, as shown inFIG.7B. Failure detection unit135of communication unit27receives a signal V output from each on-board sensor136, which is configured to detect a different UAV-associated flight related characteristic, and an analysis module139processes and analyzes all received signals V according to predetermined stored instructions. A wireless duress indicating signal W will be generated by analysis module139upon determination that the UAV has become subjected to a failure that requires termination of a current flight, whether a relative low-degree failure or a relative high-degree failure. A relative high-degree failure is generally uncorrectable and has a risk of being catastrophic and endangering nearby UAVs or bystanders, and therefore requires deployment of the parachute. The transceiver141of communication unit27transmits parachute deployment apparatus initiation signal I, rotor deactivation signal D, and an encrypted signal E transmittable to a remote station as will described hereinafter, following generation of duress indicating signal W.

One way of distinguishing between a relative low-degree failure and a relative high-degree failure is by the amplitude of vibrations reflective of vibrations experienced by the UAV body during flight. Another way is by the magnitude of angular motion such as roll, pitch and yaw experienced by the UAV body during flight, which may be indicative of a mechanical failure, such as when a rotor arm is insufficiently tightened to the UAV body.

It will be appreciated that a remote processor accessible to the operator may also receive a signal V output from each on-board sensor136.

The fully deployed parachute will be able to intercept moving aircraft fragments, if any, and to sufficiently slow the descent of the disabled aircraft so as to minimize damage of a collision involving the aircraft.

The entire safety apparatus may weigh as little as 1-1.5 kg when the object to be parachuted is a human, or even less for lighter parachuted objects. For example, the safety apparatus may weigh 260 gm for a parachuted object weighing 3.5 kg or 450 gm for a parachuted object weighing 7 kg.

FIG.14schematically illustrates an exemplary UAV150equipped with safety apparatus180of the invention, when operating, autonomously or in conjunction with a remote operator, in one of the following three modes:A. Monitoring mode—The failure detection unit monitors the signals output from each on-board sensor to determine whether they are representative of conditions of duress.The sensors generally include an inertial measurement unit (IMU) having one or more of an accelerometer, gyroscope, and magnetometer to determine a current airborne orientation and acceleration of the UAV.A predetermined flight path stored in a memory device of the failure detection unit is also monitored by receiving signals indicative of current UAV altitude which are output from a barometer, signals indicative of current UAV geographical location output from a GPS sensor, and signals indicative of current UAV speed output from an airspeed sensor.Environmental sensors, such as an UV sensor, temperature sensor and humidity sensor, may be used to estimate the deterioration of the UAV body for purposes of predictive maintenance.Monitoring continuity of wireless communication with respect to the UAV is made possible by a serial communication unit.B. Flight Abnormality mode—A flight abnormality, or a relative low-degree failure, is detected in this mode. When a relative low-degree failure, such as a crack in a rotor blade, is detected in response to sensor readings, an updated flight path is transmitted to the memory device to force the UAV to fly to a specified ground station, to undergo a repair or maintenance operation.The following is a non-limiting list of relative low-degree failures:a) deviation from a predetermined angular orientation;b) deviation from a predetermined change in angular orientation;c) deviation from predetermined translational or angular acceleration;d) deviation from predetermined altitude;e) deviation from predetermined flight path;f) predetermined drop in UAV battery voltage as determined by a voltage sensor; andg) loss in communication as evidenced by an inability to be properly guided.C. Critical Failure mode—A critical, or relative high-degree, irreversible UAV failure is detected in this mode. A relative high-degree failure may be detected when the value of a sensor reading, or a combination of sensor readings, is significantly greater than a predetermined threshold relative to that which is indicative of a relative low-degree failure. Alternatively, the profile of a signal output, such as a predetermined spike, is uniquely characteristic of a relative high-degree failure.In this mode, the UAV rotors or other flight generators are deactivated in step C1, a critical failure alert signal J is transmitted to an unmanned aircraft traffic management system (UTM) to make neighboring UAVs aware of the critical failure and an alert signal K is transmitted to bystanders in step C2to prevent occurrence of a catastrophic event, the UAV-equipped parachute is deployed as described hereinabove in step C3, and a smart landing procedure is performed, for example as described in copending WO 2018/173040 by the same Applicant, whereby a safety-ensuring processing unit is operable in conjunction with a downwardly facing collision avoidance system to calculate a required direction of descent in order to avoid a detected obstacle and to cause a sufficient number of airfoils to become circumferentially displaced, to cause the descending UAV to change its direction of descent in order to avoid the obstacle, for example autonomously, in step C4.

Safety apparatus180may be an add-on device, configured as one or more interconnected housings which are mounted on an existing UAV, in order to upgrade the existing UAV.

The failure detection unit may be provided at the bottom of the same housing in which the parachute deployment apparatus is retained.

FIG.15illustrates a UAV-based damage avoidance system200. Although only one UAV150is shown, system200is configured to communicate with a plurality of UAVs150simultaneously.

Damage avoidance system200comprises a damage avoidance base station170in data communication with the safety apparatus180of each UAV150in order to sample UAV-specific data P at a frequency of at least once a second, for example five times a second. Safety apparatus180communicates with damage avoidance base station170by one of various mobile communication technology means such as cellular, LTE, 5G, WiMax and Zigbee. Damage avoidance base station170, which is embodied by one or more computerized devices such as a web server, smartphone, laptop computer, or any other platform suitable for communicating with safety apparatus180, is able to sample UAV-specific information such as instantaneous location, direction, height, flight speed and descent rate.

Damage avoidance base station170is also in data communication by means of an Application Programming Interface (API) with at least one server, such as cellular base station server236, national hazard warning server237, vehicle navigation warning server238, social network server239and UTM cloud server240, in order to transmit thereto, generally in parallel, alarm signals in response to identification of a UAV-specific critical failure. The API is configured to prioritize transmissions sent by base station170. Damage avoidance base station170is able to communicate with servers236-240by one of various mobile communication technology means such as cellular, LTE, 5G, WiMax and Zigbee.

A corresponding communication channel is continuously established between base station170and each of servers236-240. A corresponding network monitoring device, such as a Ping WatchDog, may be used to verify that base station170is interconnected with a given server or with the airborne safety apparatus180by using Internet Control Message Protocol (ICMP) ping replies. The system administrator immediately corrects a failure related to a lack of interconnectivity if a ping rely is not returned.

System200may also comprise ground control station (GCS)230, which is manned with one or more operators, usually interacting with a remote flight controller to generate a beacon234, characterized by a broadband video and data link, to control the flight path or various components of a UAV150. One operator may control more than one UAV.

It will be appreciated that system200is operable without GCS230, when a UAV150operates autonomously.

UTM cloud server240comprises sophisticated communication and processing equipment that are configured to allocate low-altitude airspace to each of a plurality of UAVs150, so that each can fly along a unique flight path.FIG.17schematically illustrates the generation of three different-altitude flight paths251-3by UTM240, along which UAVs150a-c, respectively, are authorized to fly. For example, UAV150amay be a police UAV that allows law enforcement agents to observe an event from a different view, UAV150bmay be a UAV that is commissioned by a news agency, and UAV150cmay provide delivery services. The capabilities of UTM240are advantageously enhanced by system200, whereby it communicates with neighboring UAV as to the onset of a critical failure event involving one of the registered UAVs.

Safety apparatus180of UAV150is configured with three main units: (1) processing unit210for processing the on-board sensor outputs to determine the existence of a relative low-degree or high-degree failure, generally in conjunction with failure detection unit135and analysis unit137shown inFIG.76, (2) remote communication unit215for generating and transmitting an encrypted signal E provided with a UAV identifier to GCS230, if in data communication therewith, in order to transmit the data associated with the output from each on-board sensor, or to damage avoidance base station170so as to be indicative of a critical failure alarm signal, or to receive an encrypted command signal F from base station170, and (3) activation unit220for activating the flight generator deactivation unit, parachute deployment apparatus, warning devices for bystanders, and emergency landing equipment, if necessary.

After base station170receives critical failure indicating alarm signal E from airborne safety apparatus180, the base station in turn transmits an encrypted critical failure indicating alarm signal L to each of the servers236-240with which it is registered, generally in parallel, in accordance with the instantaneous location identifier of UAV150. All entities in communication with one the servers and in danger range of a failed UAV will be warned by the given server through a suitable emergency alert to immediately change location and to avoid damage or injury. For example, cellular base station server236will notify its subscribers who are in danger range of a failed UAV by a pop-up text message.

As schematically illustrated inFIG.18, immediately following detection of a relative high-degree failure, the UAV150dexperiencing the critical failure event (referred to herein as the “failed UAV”) transmits a critical failure alarm signal J by means of the damage avoidance base station to UTM240. The critical failure alarm signal J generally includes a current location and altitude of the failed UAV150das well as its instantaneous calculated descent path246. Since the failed UAV150dcommences a descending operation after having terminating its flight and deploying its parachute20, the failed UAV is liable to pass through the airspace of UAVs flying at lower altitudes and cause a dangerous collision. To prevent such a dangerous occurrence, UTM240transmits update signals Ua-c, each of which being representative of an UAC-specific updated flight path, simultaneously to all UAVs150a-c, respectively, which are predicted to cross, or to be in the vicinity of, e.g. within 5 meters, the descent path246of the failed UAV150d, so that these neighboring UAVs150a-cwill fly away from the vicinity of the descent path. The failed UAV150dmay generate its descent path246, which may be dynamic for example in response to visualized obstacles, following initiation of the parachute deploying operation and transmit the instantaneous descent path to UTM240.

UTM240is also adapted to alert bystanders259as to the approaching failed UAV. UTM240is able to access the local cellular base station and to determine which mobile phones (MP)248, such as smartphones, held by corresponding users are in the vicinity of the forecasted descent path246of failed UAV150d, generally at ground level243. An alert signal M is then transmitted to these mobiles phones248over the cellular network to allow the users to find immediate shelter. These users are generally afforded up to 10 seconds to find shelter since the descent rate of a parachuted UAV is on the order of 3-4 m/s and the UAV generally fly at an altitude of 50-100 m. An alert signal5may also be transmitted by UTM240to the receiver of an on-ground siren257, so that a loud warning sound will be immediately emitted thereby, to indicate to bystanders located in the vicinity of the descent path of failed UAV150dthat they must immediately significantly change their location or seek shelter.

Alternatively, UTM240alerts the neighboring UAVs and each neighboring UAV generates its own updated flight path.

In one embodiment, if the UTM fails to be interconnected to the system, as detected by the network monitoring device, the base station transmits update signals Ua-c to all UAVs150a-c, respectively, and to alert bystanders259as to the approaching failed UAV.

When failed UAV150dis a fixed-wing aircraft, parachute20may be deployed during the course of a descending operation as a fixed-wing aircraft is configured to glide following deactivation of each lift generator by the lift generator deactivation unit. The failed UAV150dtransmits the glide path by means of the damage avoidance base station to UTM240to alert the neighboring UAVs150a-c. When the failure detection unit detects a UAV acceleration that is greater than a predetermined value, e.g. 3.0 m/s2, which is indicative of the commencement of a free fall rather than of a gliding operation, a parachute deploying operation is then automatically initiated.

The descent path of the failed UAV is calculated by a processor of the damage avoidance base station.

As illustrated in the method ofFIG.18Aaccording to an embodiment, after a critical failure alarm signal is generated and a parachute is deployed in step171, data representative of the current flight conditions including UAV platform altitude, UAV location, UAV direction, UAV descent rate, wind speed, and wind direction is acquired in step173by on-board sensors. Data related to wind speed or wind direction is acquired from a local meteorological station if the safety apparatus lacks the corresponding sensor. This acquired data is transmitted in step177to the damage avoidance base station together with the critical failure alarm signal. In order to ensure reliable transmission of the alarm signal and of the acquired data to the base station even when the main battery voltage is low, or the failed aerial vehicle is suffering from a failure that prevents it from being properly guided, a backup power unit that is independent of the main UAV battery is switched on to continue powering the wireless communication equipment in step175.

The processor of the base station then calculates the descent path of the failed UAV in step179according to stored instructions from the starting altitude acquired in step173to an anticipated landing area, taking into account drift due to wind gusts and the starting UAV descent rate and direction. The base station transmits in step181a critical failure indicating alarm signal to each server with which it is in data communication, together with data representative of the calculated descent path, commanding the servers to transmit an emergency alert signal in step183to all entities, whether neighboring UAVs or bystanders located within danger range from the calculated descent path, at any point thereof. When the server is the UTM server, the emergency alert signal may be an update signal that is indicative of an aerial vehicle specific updated flight path that causes each of the neighboring aerial vehicles to urgently change its flight path to avoid collision with the failed aerial vehicle. The danger range may be a radius of up to three times the starting altitude.

Rather than landing at the end of the calculated descent path, the failed UAV is able to be maneuvered relative to the calculated descent path during landing by maneuvering apparatus, such as circumferentially displaceable airfoils in step185. The smart landing controller, which acquires the calculated descent path from the base station, is operable to divert the failed UAV from the calculated descent path during an emergency landing procedure to land on an open area, such as one having an open area of at least twice the projected area of the failed UAV and which is free from obstacles or humans, for example a roof or a plot of land.

FIG.16schematically illustrates components of safety apparatus180. Safety apparatus180need not comprise all of the illustrated components; the number of types of components provided with safety apparatus180is dependent upon the desired implementation.

Processing unit210may comprise the following on-board sensors: IMU136a, barometer136b, magnetometer136c, GPS sensor136dfor determining real-time UAV locations and for purposes of geo-fencing, UV sensor136e, temperature sensor136f, humidity sensor136g, airspeed sensor136h, and vision sensor136iand LiDAR sensor136jfor use in conjunction with a smart landing procedure. The location identifier detected by GPS sensor136dis sampled sufficiently frequently for at least once a second, for example five times a second, to be considered a real-time or instantaneous identifier, and may be transmitted in accordance with a 5G communication system. The battery voltage may be determined through the serial communication unit216of remote communication unit215, or alternatively through a voltage sensor. If the battery voltage is low, a backup power unit207continually connected to processing unit210that is independent of the UAV battery may be employed. Backup power unit207is activated by means of an internal interface, and is used to power the entire safety apparatus180, including communication unit215and the on-board sensors. All of these sensor outputs may be recorded in one or more loggers208that are protected in a black box-type arrangement. Some sensor outputs are processed by a CPU211, and some are processed by an image processor212.

In remote communication unit215, wireless communication equipment214is used to establish a data link with the GCS or with the UTM. Any time a data link is made, a UAV identifier stored in module217is included in the transmitted signal, which is encrypted by unit218. Serial communication unit216is in communication with the UAV controller201, i.e. autopilot, via bus202and with the UAV electronic speed controller (ESC)203via bus204.

Activation unit220comprises safety module activation unit221, generally configured with a rotor deactivation unit, or a deactivation unit for any other lift generator, and parachute deploying apparatus226, or deploying apparatus for any other type of fabric used for a damage mitigating operation. Activation unit220may also comprise a hazard indicator activation unit223that includes warning devices224for bystanders, such as a strobe light and a buzzer. The strobe light is visible when the UAV is located at a significant height above ground level, e.g. 150 m, and the buzzer is audible when the UAV is located at a relatively low height above ground level, e.g. 50 m, yet the bystander is afforded sufficient time to be distanced from the descending UAV after sensing the alarm signal generated by a warning device224as the descent rate of the UAV under the influence of a deployed parachute is less than 5 m/s. Activation unit220may also comprise a smart landing mechanism247configured to perform emergency landing under the guidance of a smart landing controller244, which may also command the deployment of an airbag249to reduce the impact with an existing surface during an emergency landing procedure.

In other implementations, the safety apparatus according to any embodiment described herein may be used not only for deploying a parachute, but also for deploying other damage mitigating fabric types that are retained in a chamber attached to the UAV body. For example, a net mesh made from a strong fiber such as Kevlar® or Dyneema®, when deployed, may be used to entrap a malicious UAV. Alternatively, a fire suppressing fabric, such as one made of Kevlar® and interspersed with fiberglass, may be deployed.

As shown inFIG.19, the fabric271is retained in a folded undeployed condition within chamber122. Fabric271may be folded in the same way for any desired implementation of the safety apparatus. A group of folded portions274of fabric271is retained within chamber122between two adjacent U-shaped, or otherwise hollow, e.g. concave, portions126of chamber122(FIG.13), such that a first folded portion274ais separated without contact from a second folded portion274badjacent to folded portion274a, with the exception of an expandable crease277between folded portions274aand274b. Projectile rod281is insertable within an oblique tube that is secured within the interior of a corresponding portion126, and a peripheral portion279of fabric271is attached by attachment means286to a corresponding projectile283at the distal end of rod281.

The number of projectiles283employed is dependent upon the weight or size of fabric271. For example, if fabric271has a weight of 500 g, four projectiles283that are circumferentially and evenly spaced around the periphery of circular chamber122by an angular spacing of 90 degrees and attached to a peripheral portion279of fabric271will be used to ensure an optimal uniform ejection of the fabric from chamber122.

Although not shown, fabric271is continuous with other groups of folded portions each of which retained between a different pair of hollow portions126. Chamber122may have any desired shape, for example circular or polygonal.

An exemplary folded condition is shown, such that second folded portion274bis positioned to the side of first folded portion274a, but it will be appreciated that any other suitable folded portion orientation and condition is within the scope of the invention, insofar as each folded portion274is able to be expanded uninhibitedly and rapidly upon ejection of the projectiles283from chamber122.

Fabric271is able to achieve a desired expanded dimension simultaneously with ejection of the plurality of projectiles283from chamber122by virtue of a combination of the following factors: (a) a rapidly reacting gas generator, (b) the obliquely extending hollow tubes through which the generated gas flows applies an explosive force onto each projectile, causing each projectile to be propelled distally in a different direction by a distance designed to cause the fabric to become tensioned when expanded and to perform a desired damage mitigating action, and (c) the undeployed fabric is stored within the chamber in a folded condition such that each folded portion of the fabric is separated without contact from another folded portion, allowing each folded portion to be expanded uninhibitedly and rapidly. For example, the fabric is fully deployable within less than a second, e.g. within less than 0.3 sec, following a gas generator triggering event initiated remotely by an operator or by other means, such as imaging means. The imaging means may be configured to identify a malicious UAV, or one that has intruded into an unauthorized flight zone, or to identify the presence of a fire, and to deploy fabric271once the initiating UAV provided with the safety apparatus and the imaging means is within deploying range of a target.

It will be appreciated that fabric271may also be satisfactorily expanded to perform a damage mitigating operation even when the hollow tubes through which the generated gas flows do not extend obliquely with respect to the manifold, but rather extend substantially parallel to the longitudinal axis of the manifold.

FIGS.20and21illustrate the secured positioning of safety apparatus280, which may comprise one or more components of safety apparatus180ofFIG.16, on top of a region of the platform285of UAV290which is central to the plurality of rotor arms287. Each rotor arm287carries one or more rotors289functioning as a lift generator. The fabric-retaining chamber including the hollow portions thereof may be connected to the housing of safety apparatus280. Alternatively, safety apparatus280may be securely positioned to the underside of platform285. The retained fabric may be unconnected to the housing of safety apparatus280or to the body of UAV290so as not to limit the distance to which the fabric may be propelled.

As shown inFIG.22, a damage mitigating operation may be performed after the safety apparatus is secured to a platform in step330, whether a fixed platform or a movable platform. Following triggering the MGG in step331by electrical or mechanical means, the pyrotechnic device becomes activated in step332, causing the constituent components of the propellant to react and to generate energy intensive gas. The generated gas simultaneously flows through each tube extending from the manifold in step333, applying an explosive force onto a corresponding projectile. The explosive force is converted into momentum, and each projectile is therefore distally propelled in a different direction for a predetermined distance in step334. This distance is reliably achieved by providing a sufficient dose of combustible material and a sufficient amount of activation current, to cause the fabric to be deployed in step335by being expanded to a desired dimension. The predetermined distance to which the projectiles are propelled by the explosive force may range from 15-50 m, e.g. 20 m, when the projectiles are ejected upwardly, and may be up to 100 m when the projectiles are ejected downwardly.

While the fabric is fully expanded, the projectiles, whether upwardly ejected projectiles, downwardly ejected projectiles or laterally ejected projectiles, remain attached by the attached peripheral portion of the fabric after having transferring their kinetic energy to the fabric to urge the latter to an expanded condition. Since the projectiles are propelled a significant distance, the expanded fabric is ensured of not becoming entangled with a rotating lift generator, and therefore is no need for deactivating the lift generator. A damage mitigating operation is then commenced in step336through the intervention of the expanded fabric.

FIG.23illustrates an implementation of deploying a net in order to intercept an unwanted UAV351. When unwanted UAV351is discovered, for example when found by an imaging system to be dangerously close to a security facility such as an army base or an airport, safety apparatus280of intercepting UAV350is activated. Safety apparatus280is mounted below the platform285of intercepting UAV350, so that when intercepting UAV350is located above unwanted UAV351and safety apparatus280is activated in response to an autonomously or remotely generated triggering signal, net357will be downwardly ejected to intercept and entrap unwanted UAV351. Net357may be configured with auxiliary parachute deploying apparatus359, which is configured to be automatically deployed when net357becomes engaged with unwanted UAV351, such as by means of one or more sensors, to prevent damage to underlying bystanders if the intercepted UAV351were to undergo a dangerous free fall. Alternatively, net357may remain connected to safety apparatus280or to the body of intercepting UAV350by a tow line, to facilitate the towing of intercepted UAV351to a ground station.

FIGS.24and25illustrate an implementation of deploying fire suppressing fabric362for extinguishing a burning motor vehicle364by means of downwardly directed safety apparatus280mounted on an initiating UAV360. This arrangement may likewise be used for helping to extinguish a fire of serious ramifications, for example one that is burning within a high-story structure or at a forest.

Fabric362is made of an inflammable material, which, after being deployed in a spread and expanded condition and having been positioned to cover substantially the entire source of fire, will smother the fire by limiting or altogether excluding the exposure of the fire to oxygen.

Fire suppressing fabric362is shown inFIG.24after having been ejected downwardly from the safety apparatus by the generated gas366while the projectiles283gravitationally direct the expanded fabric onto the fire369that is burning within motor vehicle364. The predetermined angular disposition relative to a horizontal plane of the plurality of projectiles283, defined by the safety apparatus, is dependent upon the weight and size of fabric362; a larger fabric requires a correspondingly larger angle relative to a horizontal plane, and vice versa for a smaller fabric. Fabric362is shown inFIG.25to completely cover the motor vehicle364while the fire is being smothered.

FIG.26illustrates an implementation of deploying fire suppressing fabric for extinguishing a fire that is burning within a parking lot372, or within any other indoor structure, by means of a plurality of downwardly directed safety apparatus units280mounted on the ceiling376of the parking lot372. A plurality of heat sensors377interspersed within parking lot372may be the stimulus of the triggering signal, in order to deploy a fabric located proximately to the source of the detected fire.

The use of fire suppressing fabric is advantageous relative to a sprinkler system or fire extinguishers since the widespread damage caused by discharged water or powder is able to be avoided.

FIG.27illustrates an implementation of deploying fire suppressing fabric by means of downwardly directed safety apparatus280mounted at the end of a fire truck ladder382.

FIG.28illustrates an implementation of deploying fire suppressing fabric by means of hand-held safety apparatus390, which may be configured similarly to safety apparatus10ofFIGS.1-4. When user392has become aware of fire399, the handle393of apparatus390is held such that the distal end394of apparatus390is facing the fire399, whether distal end394is downwardly directed, upwardly directed or laterally directed. A triggering action is then initiated by depressing a dedicated button398, or otherwise manipulating a suitable input device, to activate the gas generator. Since the projectiles are designed to be propelled a relatively small distance on the order of up to only a few meters, often less than one meter, the corresponding recoil force experienced by user392is of a sufficiently relatively small magnitude to be dissipated by the user's body.

Example 1

The parachute deploying apparatus weighing 450 gm was carried by a multi-rotor UAV having a weight of 7 kg, a diameter of 1.10 m and a height of 0.5 m. The canopy was made of Nylon 66 ripstop fabric, and had a diameter of 1.75 m. Six suspension lines, each having a length of 1.6 m, were connected to the aircraft. Three draw cords, each having a length of 25 cm, were connected to a corresponding projectile configured with an arrow-shaped head.

Three inclined tubes extended from the manifold. A projectile having a weight of 23 gm, and an arrow-shaped head connected to a rod having a length of 6 cm was inserted within a corresponding tube. Flexible polymeric material was applied to the tubes, providing sealing after insertion of the corresponding projectile therewithin.

The single MGG that was threadedly engageable with the manifold was the Autoliv A7Zr2.1, IMI-Type 610258300, manufactured by Autoliv, Ogden, Utah. The MGG had a diameter of 1.5 cm and a length of 4 cm. The pyrotechnic device produced 8 liters of nitrogen.

The projectiles were propelled a distance of 112.5 cm within a time period of 0.28 seconds after the trigger was initiated.

Example 2

During the flight of a six-rotor UAV, a crack developed in one of the rotor blades. The failure detection unit initiated the Flight Abnormality mode, and the UAV was forced to fly to a specified ground station, in order to repair the crack.

An accelerometer operable in the 200 Hz range was employed to acquire vibration amplitude readings. Vibration amplitude of less than 0.5 m/s2is reflective of normal UAV operation. Vibration amplitude of greater than 0.5 m/s2is reflective of an anomalous flight condition, such as the development of a crack in a rotor blade. Vibration amplitude of greater than 3.0 m/s2is reflective of a critical failure that requires the immediate termination of flight and the deployment of a parachute.

While some embodiments of the invention have been described by way of illustration, it will be apparent that the invention can be carried out with many modifications, variations and adaptations, and with the use of numerous equivalents or alternative solutions that are within the scope of persons skilled in the art, without exceeding the scope of the claims.