WO2016103264A1

WO2016103264A1 - A method and apparatus for extending range of small unmanned aerial vehicles - multicopters

Info

Publication number: WO2016103264A1
Application number: PCT/IL2015/051248
Authority: WO
Inventors: Noam Cohen
Original assignee: Noam Cohen
Priority date: 2014-12-24
Filing date: 2015-12-23
Publication date: 2016-06-30

Abstract

The method and apparatus introduced in this invention relies on utility power transmission/distribution lines as a source of energy for extending the mission range of unmanned aerial vehicles, and/or on the deployment of a perched Inductive recharge pod on the power lines.

Description

A METHOD AND APPARATUS FOR EXTENDING RANGE OF SMALL UNMANNED AERIAL VEHICLES - MULTICOPTERS

FIELD OF THE INVENTION

[Para 1 ] The method and apparatus introduced in this invention relies on utility power transmission/distribution lines as a source of energy for extending the mission range of multicopters, and/or on the deployment of a perched Inductive recharge pod on the power lines.

BACKGROUND OF THE INVENTION AND PRIOR ART Claim of Priority:

This This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62/096,782 titled "Extended range multicopter capable of landing on utility power lines to inductively harvest radiated energy and charge its batteries", filed December 24, 201 4, (hereinafter referred to as "App. 62 /096,782"), the disclosure of which is hereby incorporated in its entirety by reference herein.

[Para 2] Multicopters are a type of u nmanned aircraft whose small size and electrical propulsion & control systems allow new form factors and operational envelopes not previously possible by traditional aircraft designs. For example, their small form factors, low costs, and ease of remote piloting potentially allow them to be used for applications such as traffic or border enforcement, agricultural or power line inspection, and parcel delivery, at costs & efficiencies not practical with current helicopters or fixed wing aircraft. As further example, having a vehicle footprint on the order of 1 m² (or less) and vertical takeoff and landing ability, while not having a large central rotor .(requiring safety clearance), allows deploying a mu lticopter from dense urban locations, and allows it to land in crowded or otherwise restrictive locations. [Para 3] Yet a chief limitation of multicopters is their limited operating range and flight time. Being entirely battery operated (as opposed to having a fuel-based power source such as a jet engine), means they are limited by the power density of the batteries, which might be up to few hundreds of Watt-hours per Kilogram of battery (for typically used Lithium Ion batteries); For typical small-footprint, low cost multicopters this would mean an operating range of up to few tens of kilometers, and flight time of less than one hour (often much less), which is insufficient for many applications. The object of this invention, in conjunction and in continuation with, and as an alternative/complementary method to App. 62/096,782, is to remove this limitation of flight range and mission duration and to extend the operating range of multicopters. [Para 4] An embodiment is an example or implementation of the inventions. The various appearances of "one embodiment," "an embodiment" or "some embodiments" do not necessarily all refer to the same embodiments. Although various features of the invention may be described in the context of a single embodiment, the featu res may also be provided separately or in any suitable combination. Conversely, although the invention may be described herein in the context of separate embodiments for clarity, the invention may also be implemented in a single embodiment.

[Para 5] Reference in the specification to "one embodiment", "an embodiment", "some embodiments" or "other embodiments" means that a particular featu re, structure, or characteristic described in connection with the embodiments is included in at least one embodiments, but not necessarily all embodiments, of the inventions. It is u nderstood that the phraseology and terminology employed herein is not to be construed as limiting and are for descriptive purpose only.

SUMMARY OF THE INVENTION

[Para 6] The method and apparatus conceived here relies, in one embodiment, on utility power transmission/distribution lines as a source of energy for extending the mission range of mu lticopters; and in another embodiment, on the deployment of a device hereto referred to as a "Perched Inductive Recharge Pod" (or hereto abbreviation as "Recharge Pod" or "Pod") on the power lines themselves. Long flight missions would be planned to cross or otherwise coincide with power lines or recharging pods, such that prior to the multicopter exhausting its battery power, it would perform a landing directly on one of the conductors of the powerline, or conversely on top of, a recharging pod; The landing would be facilitated by an arrangement of the multicopter that would allow it to balance on top of the line, also described in this application. Having thus landed, an inductor coil (or plurality of such coils) purposely included and situated as part of multicopter's structure wou ld become situated in the magnetic field created by the alternating current in the line, such that an electromotive force is generated in the coil, which wou ld in turn be used to charge mu lticopter's batteries. In an alternative embodiment, the multicopter would make electrical contact to purpose-designed contacting devices extending from a recharging pod, closing an electrical circuit that comprises of an inductive coil(or plurality of such coils) purposely included, which is part of the recharging pod and additional circuitry, partially situated in the multicopter or, in another embodiment of the invention, situated as part of the mu lticopter structure. Here too, the circuit wou ld allow to inductively "Harvest" the magnetic field creating a current to charge mu lticopter's batteries. Such "harvesting" of the magnetic field not only allows increased operational range but also creates beneficial environmental effects, by replacing fossil-fuel based activity (e.g. delivery trucks) with environmentally cleaner electrical vehicles. Upon having thus charged its batteries the multicopter would re-activate its motors, mechanically disengage from the line/ Pod and take off in order to continue its task. [Para 7] As opposed to several other patents, which describe an alternative method of achieving same or similar goal, relying on field- deployed apparatus that comprises of charged/charging batteries and a battery exchange system that performs a battery swap on a visiting vehicle, this invention dispenses with the need for costly deployment of equ ipment in the field: In the embodiment that relies on the multicopter carrying its own coil, no additional investment in the field is needed whatsoever, as the power replenishment will be done directly from existing, un-modified utility power lines. In the embodiment that relies on perched recharging pods, the deployment of field equipment is minimal (yet introduces several advantages vs the preceding embodiment), and none of this equipment requires complex & accurate controlled electromechanical systems. The importance of achieving power replenishment for a visiting vehicle, without the use of such electromechanical apparatus, is one of cost effectiveness, for two reasons: The first is the basic cost of each piece of field-deployed apparatus (a very large nu mber of which need to be deployed); And the second is the reliability & lifetime of such devices, many of which will be deployed in difficult to reach/service locations (indeed - power lines being such a case), hence the value of a very simple and robust field- deployed device.

[Para 8] As with all other aircraft design, in this case as well, it is preferable to minimize weight e.g. by utilizing existing/other structures to implement various features of the invention; For example avoid addition of various mechanical implements for the visiting multicopter to physically engage with the power line, or minimize additional structures needed for optimu m operation of the inductive coils within the given magnetic field of the line.

[Para 9] One preferred arrangement presented below ("Hinged airframe") works by having two halves of the multicopter's structure joined by a hinge or hinge-like mechanism, which allows their relative rotation arou nd an axis parallel to the ground. In landing on a power line, the multicopter would orient itself such that the axis of the hinge be parallel to the line; and upon lowering itself on the line and reducing the power of its rotors for landing, the two halves would partially rotate towards the ground, lowering multicopter's center of gravity to a point below the line (facilitating its balance when suspended on the line), as well as mechanically "grasping" the line for added stability.

BRIEF DESCRIPTION OF THE DRAWINGS [Para 1 0] The following drawings relate to two embodiments of the invention. One embodiment is a multicopter capable of landing on utility power lines to inductively harvest radiated energy and charge its batteries, (hereinafter referred to as "embodiment A" or "EMB. A"), and another embodiment of the invention using perched recharging pod, (hereinafter referred to as "embodiment B" or "EMB. B"). The embodiments will be described in the detailed description and the appended claims that follow, and in the accompanying drawings, wherein:

[Para 1 1 ] Fig. 1 shows a schematic illustration of an exemplary multicopter;

[Para 1 2] FIG.2 relates to EMB.A and illustrates a utility power line and inductive pickup coils.

[Para 1 3] FIG.2a relates to EMB.B and illustrates a different configuration of inductive coils.

[Para 1 4] FIG.3 Relates to EMB A and presents one possible configuration in which a mu lticopter is equipped with said inductive coils.

[Para 1 5] Fig 4.Relates to EMB A and illustrates an alternative configuration in which coils' orientation is different with respect to the wire and the multicopter, exemplifying one of many such possible configurations.

[Para 1 6] Fig.5 Relates to EMB A and illustrates a preferred embodiment in which two coils (202) are employed. [Para 1 7] Fig. 6 Relates to both EMB. A & B and illustrates a further preferred embodiment hence referred to as a "Hinged airframe".

[Para 1 8] Fig. 7 Relates to both EMB. A & B and fu rther illustrates the "Hinged Airframe" embodiment, in a state of having landed on a power line.

[Para 1 9] Fig. 8 Relates to EMB A and illustrates another preferred embodiment in which a known "Ducted rotor" multicopter design is used.

[Para 20] Fig. 8a Relates to EMB B and further illustrates the concept of "hinged airframe" and how it facilitates the "landed state" of the multicopter on a power line.

[Para 21 ] Fig. 9 Relates to EMB A and illustrates a different preferred embodiment to the inductive coils than shown in figure 2 and the other previous figures.

[Para 22] Fig. 9a Relates to EMB A and illustrates that in the dimension parallel to the power line (204), such a toroidal-like embodiment might be extended to an arbitrary degree

[Para 23] Fig. 1 0. Relates to EMB A and illustrates a preferred embodiment that relies on a coil arrangement illustrated above in figure 9.

[Para 24] Fig. 1 1 & 1 1 a Relate to both EMB A & B and illustrate yet another preferred embodiment in which the body (1 00) of the mu lticopter is of relatively small volume/width, and the spacing of the rotors (1 02) with respect to each other and with respect to the body is achieved by means of structural elements such as strut or poles.

[Para 25] Fig. l l b Relate to EMB A. and shows part of an embodiment similar to that shown in figu re 1 1 , only without the dedicated rotor carrying structures.

[Para 26] Fig. l 2&1 2a show a top and front view of the power line (204) and one of the coils (202) in order to illustrate a particular embodiment which supports a feature called "emergency line disengagement procedu re".

[Para 27] Fig. l 3 Relate to EMB B and illustrates a Perched Inductive Recharge Pod, or exemplary embodiment thereof.

[Para 28] Fig. l 4 Relate to EMB B and describes one embodiment of a perched inductive recharge pod in which a number of such coils are partially symmetrically arranged around the power line.

[Para 29] Fig. l 5 Relate to EMB B and illustrates an embodiment in which the coil 202 consists of a larger number of loops and/or a thicker wire gauge compared to the embodiment in fig. 1 3.

[Para 30] Fig. l 6 illustrates an approach of a multicopter and includes the discharge probe 45 1 , which is an independent and potentially important part of the invention.

[Para 31 ] Fig. l 7 is a flowchart describing several phases of deployment and operation of the invention. DETAILED DESCRIPTION OF THE DRAWINGS

[Para 32] Fig. 1 shows a schematic illustration of an exemplary multicopter; the embodiment shown is a quadcopter (equipped with four rotors), which will be referenced and discussed in subsequent diagrams for simplicity; however the invention is equally applicable and relevant in case of six rotor (hexacopter), 8 rotor or any other nu mber of rotor arrangements, as it is to hybrid rotor-wing type of aircraft designs (i.e. that comprise of rotors together with one or more fixed wings). The multicopter comprises of a body (1 00), rotors (1 02), each of which is affixed to a motor (1 04), optical apparatus such as cameras and other sensors (1 06), antenna(s) (1 08), and landing appendages (1 1 0). Included within the body (1 00) are electronic circuitry, batteries, radio transmitters and receivers, other electronic devices and potentially a payload (not shown).

FIG.2 relates to one embodiment of the invention and illustrates a utility power line (204), the magnetic field produced arou nd it by the electrical current it carries, whose directionality is indicated by the arrows (208), and an exemplary configuration of inductive coils (202) formed by wire loops (206) whose cross-sectional area can be seen to encompass part of the magnetic field. As per Faraday's law, time-varying changes in the current carried by the line (such as in a 50hz AC utility line) will induce an EMF in the coils, a nu mber of whom can be connected in series resulting in higher obtainable EMF. The illustrated configuration consists of coils with a rectangular cross section; however this is merely exemplary and might consist of a differently polygonal or circular form. [Para 33] Fig. 2a relates to EMB B and illustrates an embodiment of the inductive coils as might be configure in case of EMB B. It shows a utility power line (204), the magnetic field produced arou nd it by the electrical current it carries, whose directionality is indicated by the arrows (208), and an exemplary configuration of said coil (202) formed by wire loops (206) whose cross-sectional area can be seen to encompass part of the magnetic field. As per Faraday's law, time-varying changes in the current carried by the line (such as in a 50hz AC utility line) will induce an EMF in the coil. The illustrated configuration consists of a coil with a rectangular cross section, and with a relatively limited number of loops (such that the angular extent of the coil around the power line is very small; i.e. the coil does not surround the wire, to any degree). However this is merely exemplary and might consist of a different (e.g. polygonal or circular) cross sectional form; and/or might form a torus or a section of a torus extending partially or entirely around the power line, too. [Para 34] Fig. 3. Relates to EMB A and presents one possible configuration in which a multicopter is equ ipped with said inductive coils (206) such that when situated in the proximity of a utility power line (204) would allow "harvesting" the varying magnetic field produced by the line in order to charge the multicopter's batteries with the induced EMF and resulting current.

[Para 35] Fig.4 relates to EMB A and illustrates an alternative configuration in which the coils' orientation is different with respect to the wire and the multicopter, exemplifying one of many such possible configurations. Due to the circu lar symmetry of said magnetic fields, the induced EMF in the coils is indifferent to such differences in orientation as illustrated.

[Para 36] It is assumed that during the proposed charging operation, the multicopter and its attached coils are stationary with respect to the wire; all variation in the derivative section of Faraday's law is assumed to originate from the time-varying nature of the current in the utility wire. Likewise it is assumed that orientations of the coils is chosen such that the cross-sectional area of the coils with respect to the magnetic field is chosen to be maximal; Yet changing the orientations in a rotational manner around the wire as illustrated in figure 4 does not influence this cross section with respect to the magnetic field).

[Para 37] Fig.5 Relates to EMB A and illustrates a preferred embodiment in which two coils (202) are employed, and in which said coils are "embedded" within the structure of multicopter's airframe (otherwise needed to house mu lticopters' various electronic components). (note: for further simplicity and clarity, the landing appendages and antenna previously shown are not included in this and in the following diagrams).

[Para 38] Fig. 6 Relates to both EMB. A& B(except for the fact that it includes embedded coils, which relay to EMB A only and do not il lustrate a pod attached to the wire existing in EMB B). Fig. 6 illustrates a fu rther preferred embodiment hence referred to as a "Hinged airframe.

[Para 39] The main/central structure or airframe is now shown to consist of two parts, 1 00a and 1 00b. These two halves are connected by a hinge (300) around which some measure of relative rotation of the two halves can take place. For example, one rotational position is employed when in flight, and a different rotational position after having landed. Specifically, as fu rther explained below, the act of landing on a wire and reducing/extinguishing power/speed of the rotors will cause the two halves to rotate downwards at their edges. This embodiment might also make use of a structural feature ("Powerline Engagement Structu re") such as an elongated slot (31 0) formed between the two airframe halves, which mechanically engages with the with the power line (204) and facilitates landing upon it in a stable manner.

[Para 40] Fig.7 Relates to both EMB A & B (except for the fact that it includes embedded coils, which relay to EMB A only, and do not illustrate a pod attached to the wire existing in EMB B). Fig. 7 further illustrates the "Hinged Airframe" embodiment, in a state of having landed on a power line, showing the role of the two hinged halves and of the power line engagement structu re (31 0). Upon approaching a power line on which a landing is planned, the multicopter would align itself with respect to the power line (204) such that the Powerline Engagement Structure is oriented to mechanically engage the line. In the illustrated embodiment, as in figure 2 , here too the powerline engagement structure is in the form of an elongated slot, oriented such that it is in parallel to the power line. Once such aligned, the multicopter would lower itself onto the line such that a section of the line wou ld be located wholly or partially within the elongated slot; Further reduction of power to the rotors would now cause the multicopter's weight to be partially supported by the powerline; Still further reduction, or extinction, of power would now practically eliminate the lift provided by the rotors, which (in lieu of the location of the rotors on the extremities of the multicopter) would in turn extinguish the upwards force acting against gravity on the extremities of the multicopter. At the same time, having the central portion of the multicopter supported by the power line (204) results in an upwards force being applied (by the power line) to the center of the multicopter. The net result of this change in forces acting on the extremities and the center of the multicopter's airframe will now cause the two halves (1 00a, 1 00b) of the airframe to rotate downwards arou nd hinge (300), resu lting in the illustrated state. It should be highlighted that in this state, the center of gravity of the mu lticopter moves to a lower position, such as a position located vertically below the power line, creating a balancing effect that stabilizes the multicopter in this position on the power line. A further feature of this embodiment is the elongated slot (31 0), which in this state, becomes narrower and mechanically grasps the power line (204), adding to the mechanical stability of the "landing" position on the power line,

Upon need (such as for example upon having determined that the batteries have been sufficiently charged), re-powering the rotors would create an u pwards force that, in lieu of the rotors being positioned on the extremities of the airframe, would raise the extremities of the airframe, causing airframe halves (1 00a, 1 00b) to rotate around hinge (300) in the opposite direction to the one described above, releasing the power line and allowing the multicopter to dis-engage from it and take off.

[Para 41 ] Fig.8 relates to EMB A and illustrates another preferred embodiment in which a known "Ducted rotor" multicopter design is used. In this arrangement and embodiment, each of the rotors (1 02) is su rrounded by a portion of the airframe (1 00a or 1 00b) that forms a duct (1 04) around the rotor, one advantage of which is to protect the rotors from striking external objects & surfaces in the event of in-flight collision, preventing or reducing damage to the rotors or to said external objects & surfaces. In the context of this invention, a practical implication of such is that the airframe extends further away from the centerline of the multicopter, so as to surround the rotors. This creates a larger area within the airframe that encompasses the power line's (204) magnetic field. According to Faraday's law, the magnitude of the electro motive force induced in the coils is proportional, amongst other things, to the area of the coil which encompasses the magnetic field; Thus it becomes advantageous to embed the coils (202) within the two halves (1 00a, 1 00b) of such a larger airframe, allowing for larger cross sectional area of the coils and this faster/more efficient charging of the multicopter's batteries. As stated before, this preferred embodiment and its advantages are not affected by the cross-sectional shape of the coils, which cou ld be rectangular (as shown), polygonal with a smaller or larger number of facets, rounded or any other shape, e.g., as per the other requirements from the airframe.

[Para 42] Fig.8a relates to EMB B and illustrates another embodiment in which a known "Ducted rotor" multicopter design is used, (the Pod was omitted for sake of clarity/simplicity). In this arrangement and embodiment, each of the rotors (1 02) is surrou nded by a portion of the airframe (1 00a or 1 00b) that forms a duct (1 04) arou nd the rotor, one advantage of which is to protect the rotors from striking external objects & surfaces in the event of in-flight collision, preventing or reducing damage to the rotors or to said external objects & surfaces. The isometric perspective of figure 4 further illustrates the concept of "hinged airframe" and how it facilitates the "landed state" of the multicopter on a power line, with the two airframe halves 1 00a and 1 00b straddling power line 204 and assuming a lower position vs the "non-landed", flying state. For sake of simplicity, several previously mentioned featu res such as antenna, landing appendages, and cameras and sensors have been omitted from this diagram.

[Para 43] Fig.9 relates to EMB A and illustrates a different preferred embodiment to the inductive coils than shown in figure 2 and the other previous figures. Viewed on-end it appears as a semi-toroidal form; Indeed this embodiment might be seen as an evolution or generalization of a torus. The figure illustrates the power line (204) and surrounding tangential magnetic field (208), part of which field travels through the loops (306) of the coil arranged around a former (302) of semi-toroidal shape, and in doing so create the possibility of generating an induced Electro Motive Force according to Faraday's law.

[Para 44] Fig.9a relates to EMB A and illustrates that in the dimension parallel to the power line (204), such a toroidal-like embodiment might be extended to an arbitrary degree, by "extruding" (=extending) the semi-toroidal coil in one dimension along the power line. This has the effect of enlarging the cross section of the coils and thus the area of the encompassed magnetic field, and thus (as per Faraday's law) the magnitude of the induced electro motive force. It should be noted that while the illustration refers to an exactly semi-toroidal (i.e. - 1 80 degrees out of the full 360 degrees required for the torus to completely encompass the power line), any other fraction of a full torus is possible and has no material impact on the invention. Indeed, the embodiment illustrated in figure 2 might be seen as consisting of two very short sections (i.e. ~1 0 degrees out of 360) of a torus. Yet the importance of this particular embodiment is that it allows using an inductor area with a smaller area, compensated for by the much larger number of loops (as stated by Faraday's law; Em xNA, A being the area of the inductor encompassing the magnetic field within a plane perpendicular to the magnetic field lines, and N being the number of loops of coil).

[Para 45] Fig. 1 0. Relates to EMB A and illustrates a preferred embodiment that relies on a coil arrangement illustrated above in figure 9. An extended semi-toroidal (or partially toroidal) induction coil (302), or plurality thereof, is embedded within the two halves of the airframe (1 00a, 1 00b) close to its center, around the Powerline Engagement Structure (31 0) and thus, upon having landed on power line (204), in close proximity to the line; As the intensity of the magnetic field su rrounding the line decreases with the reciprocal of the distance from the line, it is of advantage to some arrangements to minimize the size (and consequently weight) of the induction coil, harvesting energy from only the strongest part of the field, closer to the line. In particular, in such an embodiment, the former of coil (302), on which the wire loops are wound, might be made of a flexible (e.g. ru bber-like) material so that it's flexing complies with the relative rotation of airframe halves (1 00a, 1 00b) when engaging/disengaging from line (204) as described above.

[Para 46] Fig. l 1 & 1 l a Relate to both EMB A & B.Fig. l 1 illustrates coils 202 which belong to EMB A only, and neither of the two illustrate the Pod, which wou ld be there in case of EMB B. and illustrate yet another preferred embodiment in which the body (1 00) of the mu lticopter is of relatively small volume/width, and the spacing of the rotors (1 02) with respect to each other and with respect to the body is achieved by means of structu ral elements such as strut or poles (400) that extend outwards from body (1 00) and carry the rotor motors (1 04) at their ends. Figs 1 1 and 1 1 a exemplifies such an embodiment utilizing four rotors and a corresponding number of struts, yet the embodiment described heretofore refers and is applicable to any nu mber of such mou nted rotors. In EMB A, (Fig. 1 1 ), induction coils (202) are not embedded within the body (1 00) of the multicopter, nor are their extent limited by the geometrical extent of the body (1 00). Rather, the coils extend outwards from the center of the multicopter's geometry (i.e. from the area where power line (204) would be situated during a recharging stop) reaching up to or close to the extremity of the rotor-carrying structures (400). These same rotor carrying structures (400) also act as mechanical su pport/anchoring points for the outer portions of the coils. As with the embodiments illustrated in figures 6, 7, 8 and 9, this embodiment too is equ ipped with a hinge-like device allowing said rotor carrying structures together with affixed rotors to rotate with respect to each other as part of the power line landing procedure described in this patent, as well as with a powerline engagement structu re similar to the one described above. The hinge mechanism (as well as other structures such as landing appendages, aerials, powerline engagement structu re, cameras and sensors) is omitted from the diagram for clarity only; however arrows (402) illustrate the down and up rotational motion of the multicopter's extremities around such a hinge. [Para 47] Fig. l l b relate to EMB A. and shows part of an embodiment similar to that shown in figu re 1 1 , only without the dedicated rotor carrying structures (i.e. the coil members themselves, sufficiently mechanically strengthened, serve as the rotor carrying structures); Fig. l l b shows an enlarged view of part of this embodiment only, omitting approximately half of it, in order to focus and emphasize the ability to replace the motor carrying struts by a mechanical load bearing (mechanically strengthened) coil structure.

[Para 48] Fig. l 2&1 2a show a top and front view of the power line (204) and one of the coils (202) in order to illustrate a particular embodiment which supports a feature called "emergency line disengagement procedu re", described later in this docu ment. In figure 1 2 a top view is shown, whereby the exemplary rectangu lar cross section of coil (202) is clearly seen. Each of the 4 sides of said exemplary rectangu lar shape locates a different geometrical d istance from powerl ine (204); and since the mag netic field wh ich rad iates from powerl ine (204) decreases with the reciprocal of the distance from the powerli ne, each of said 4 sides experiences a d ifferent magnetic field strength. Now considering a single cu rrent carrying wire within each of the 4 sides, given the d irections of cu rrent flow and magnetic field as illustrated , said wire wou ld experience a force as per each of Fi -F₄, for the correspond ing fou r sides, as illustrated; Wherein F3 and F₄ are of equal magnitude and opposite directions, thereby cancelling each other out; and wherein Fi and F₄ are also of opposite di rections but with Fi > F₄ due to the different magnetic field strengths acting on the correspond ing two sides of the coil. Consequently the net force "felt" by the entire coil, is shown as Ftotai. Figu re 1 2a now shows same powerline (204) and coil (202) from the front direction of the mu lticopter, i.e. parallel to the axis of the powerline. Force Ftotai is also marked. Th is front view now hig hlights that in th is embod iment the location of the coil (or a portion thereof) with respect to the power line is such that a mechanical/geometrical offset exists between the centerline of the coil, on which Ftotai acts, and the power line (marked as Doffset ). Si nce the mu lticopter is resting balanced on the powerl ine, the effect of Ftotai acting in such an off-center man ner with respect to the powerline on which the mu lticopter rests is to create a rotational moment, i llustrated as ■"moment, which, i n lieu of the coil being connected to the rest of multicopter's body will translate into a rotational force of the multicopter, or at least of one half of multicopter's body with respect to the other half (their connection point and therefore the pivot, being located off-center from the powerline itself). The net effect of this is, qualitatively speaking, to cause an upward relative rotation of half of multicopter's body towards an "u n-engaged" position with respect to the power line, and to furthermore "flip" (= rotate) the multicopter off the power line.

Fig. l 3Relate to EMB B and illustrates a Perched Inductive Recharge Pod, or exemplary embodiment thereof. It comprises of coil 202 formed by wire loops 206; of one or a plurality of perching device(s) 2 1 0, by which it is mechanically suspended from the power line 204 while being held in close proximity to it, in order for it to encompass a portion of the power line's magnetic field which is of highest intensity (closest to the power line); and of contacting devices 220 which wou ld allow a multicopter to form an electrical connection to the coil. Similar to figu re 6, here too the Recharge Pod comprises a coil of rectangu lar cross section; It also comprises of a relatively small number (e.g. more than 1 0 but less than 1 000) of loops, such that it's dimension in one direction perpendicular to the power line is similar to that of the power line itself. This might typically be more than one centimeter but less than thirty centimeters. In the second perpendicular direction (i.e. the direction of being suspended - Vertically, towards the ground) it might typically be of a dimension which is more than five centimeters but less than one meter; And in the direction parallel to the power line it might typically be of a dimension of more than half a meter but less than ten meters; Said dimensions being chosen so as to maximize the generated EMF and amount of power obtainable from the coil, while at the same time complying with safety, mechanical, weight and other restrictions which might be required by the company owning and operating the power line. It should be stressed that the illustrated embodiment is purely exemplary, and other geometries (such as two or more coils symmetrically balanced on both sides of the power line; or a toroidal coil of smaller cross section but which encompasses the power line, etc.) are equally viable and deemed equally part of this invention.

[Para 49] Fig.1 4 relates to EMB B and in particular, describes one embodiment of a perched inductive recharge pod in which a number of such coils are partially symmetrically arranged around the power li ne such that their extending horizontally the sides of the power line might be utilized as a mechanical platform for the landing of a multicopter not equ ipped with an arrangement such as "hinged airframe" described above, which might in certain cases be deemed as an advantage (e.g. allowing use of the recharging pod to 3^rd party multicopters based on different design). [Para 50] Fig.1 5 relate to EMB B and illustrates an embodiment in which the coil 202 consists of a larger number of loops and/or a thicker wire gauge compared to the embodiment in fig.1 3, such that it extends partially around power line 204 in a toroidal geometry, still possessing the featu res and functionality previously mentioned (e.g. perching device 21 0 and contacting devices 220). A potential advantage of such an embodiment is that the larger number of loops in the coil will enable reducing the area and the radial extend of the loops away from the power line, such that the overall radial extension of the pod away from the power line might be reduced without compromising power generation ability. Such a more compact device might be desirable by the power company for reasons of safety, detailed below.

[Para 51 ] Fig. 1 6. illustrates an approach of multicopter 1 01 , comprising of body 1 00, motor-carrying structures 400, motors 1 04 and rotors 1 02, a hinge-like device allowing motor-carrying structure 400 to rotate downwards as part of landing on a power line (not illustrated, as well as other featu res not illustrated, for clarity) approaching a perched inductive recharging pod 201 . It also includes the discharge probe 451 , which is an independent and potentially important part of the invention. [Para 52] The multicopter approaches the recharging pod and power line from above. Fig.1 6 fu rther illustrates two additional features of the multicopter which are part of the invention. The multicopter is also equ ipped with contacting devices 222 , designed to interface mechanically and electrically with contacting devices 220 of the recharging pod; And with a static electricity discharge wand 45 1 , designed to safely discharge static charge owing to the high voltage potential likely to exist between the mu lticopter and the power line. Since the power line might have a potential of hundreds of thousands of volts with respect to grou nd potential (at which the multicopter is likely to have been at, u pon its initial takeoff), a brief but significant discharge might take place as the multicopter will approach the power line for landing. In order to avoid damage by such discharge to various elements of the multicopter, a discharge wand is designed included such that it will safely absorb said discharge. The wand comprises of conductive wand body 451 ; of wand tip 452 , which in some embodiments might be made of a durable material not damaged by repeated discharges; and of wand coupling 450 by which the wand is connected to multicopter body 1 00 and might be of a stationary/flexible mechanical nature or a controllable movable nature. The wand might also be connected to means of verifying the occurrence of a discharge, such as an electronic current sensor and/or a computerized vision system to also aid with its controlled contacting of the line.

[Para 53] Fig.1 7. is a flowchart describing several phases of deployment and operation of the invention. DETAILED DESCRIPTION AND BEST MODE OF IMPLEMENTATION

[Para 54] This invention consists of a method and an arrangement intended to extend the operating range of small u nmanned flying vehicles known as "Multicopters", which have to date been used mostly as toys, whose flight time and range is limited by battery capacity. These vehicles have potential in various commercial or government sector applications such as traffic enforcement, border/security surveillance, agricu ltural/infrastructure inspection (e.g. inspection of utility power lines), ultra-rapid delivery of commercial items and more - however many of which will require flight times & ranges in excess of what is possible today. The main bottleneck to longer flight times and higher ranges is the energy density of batteries. Current best practices make use of Lithium Ion or Lithium Polymer (LiPo) batteries which can provide close to 200 watt-hours per kilogram of battery (but usually less). This might typically allow for flight times of around half an hou r, and often less so when carrying significant payloads. And when translated into operating range, it works out to few kilometers, or at most few l O's of km. In order to successfully perform many of the roles such as mentioned above, a very significant increase in flight time and operating range is needed, for which there are currently no effective solutions. [Para 55] For the sake of clarity, the usage of the term "multicopter" herein refers to an unmanned flying vehicle equ ipped with plurality flight rotors.

[Para 56] This invention relies on existing deployed infrastructu res, namely utility power lines, which carry very significant amounts of electrical power, of which a minute fraction of which might be "harvested" in order to recharge it's batteries and extend its flight time and range; and in EMB. B, on "recharging pods" that are deployed at chosen locations on the power lines, and who inductively convert a fraction of the power line's magnetic field into an AC voltage made available at its electrical terminals for multicopters to recharge on.

[Para 57] One part of the invention is the method of planning multicopter flight/ mission routes alongside or in the vicinity of or intersecting with utility power lines, (and in case of EMB B around or at the deployed recharging pods), such that the flight/mission route might include "recharging stops" on said powerlines or at the recharging pods. These stops will be planned according to "Maximal Flight Segment" based on flight time & distance available to the multicopter and its internal batteries, and flight conditions such as payload weight, weather conditions and of course the requ ired destination. The path from multicopter's originating/base station to the required destination will be divided into segments, each of which is equal to or shorter in length than the Maximal Flight Segment. The point at which one segment ends and the next segment begin may be located on utility power or on a previously deployed recharging pod, at which location the multicopter will perform a recharging stop. [Para 58] Such above mentioned planning activity will take place based on a purposely prepared map that describes data such as paths of utility power lines, their type (e.g. operating voltage, number of phases carried), their mechanical structure (e.g. exact location of pylons, type and height of pylons, type and gauge of cables used, geometrical arrangement of the carried phases, etc.) and parameters related to potential or existing commercial agreements with the owner/operator of the utility power lines.

[Para 59] In addition to above said map, fu rther infrastructures for the enablement of this activity, deemed as part of the invention, are software applications, data reporting and collection procedu res, and one or a plurality of databases for storing and managing flight and recharging- stop related data; such data comprising of (but not limited to) flight itineraries, recharging stops made, their timing, location, duration, and amount of power harvested du ring a recharging stop (i.e. in watt-hours), allotment of landing locations and landing "windows" (i.e. time slots); recharging stop landing authorizations (whether automated, manually sent, in advance/ahead of time or in "real time"/du ring flight mission, sent directly to a multicopter or to a mu lticopter control center, or whether sent by the utility power line operating/owning company, or by the multicopter operating/owning company, by a regulatory or traffic control authority, or by a related third party); other billing related information such as but not limited to landing fees paid by multicopter operating/owning company to the utility company operating/owning company or invoices relating to such fees; the transactional/commercial model agreed upon between specific utility power company and a specific owner/operator of multicopters, such as but not limited to fixed periodic payments, per-landing stop payments, per watt-hou r payments, etc.; alternate routing/landing spot allocation; recharging stop queuing; emergency situation reports/instructions such as but not limited to technical faults or other situations affecting the ability to perform planned recharging stops (such as but not limited to weather conditions, electrical load conditions, and others); requests for unschedu led/unplanned recharging stops arising out of situations such as but not limited to change in weather conditions, change in commercial priorities, technical malfunctions and others - as well as the requisite approvals and/or instructions relating to such unscheduled/unplanned stops; planned recharging power load per given future timeframe per given power line/state/sector/ region/other subdivision; All such data requ ired to manage, regulate, transact, su pervise and monitor the collective activity of the multicopters' relying on and making use of recharging stops on said power lines or on the charging pods which are deployed on utility power lines.

[Para 60] In case of EMB. B, the deployment of said Perched Inductive Recharging Pods will take place u nder agreement with and in coordination with the entity that owns and/or operates the powerlines. Locations of deployment will be chosen by the owner/operator of the multicopters based on its existing or anticipated business and operational needs, in agreement and coordination with the powerline company. The mu lticopter fleet operator might choose the locations according to considerations such as (but not limited to) the deployment and geography of its logistical centers (i.e. locations from which the multicopters are dispatched); the location and geographical spread of specific customers and/or customer popu lations; flight paths that might be employed by the multicopters, for example as a function of flight path restrictions (e.g. closed air spaces) or weather conditions; power-line owning and operating companies with whom suitable commercial agreements are in place; operational range limitations imposed by battery/ multicopter technology; expected scheduling of activity, and other considerations. The pods might be deployed (i.e. perched and secured on the powerline) by several means, including but not limited to helicopters or linesmen (i.e. manually) belonging to the utility power company or a contractor to thereof; or by purpose designed multicopters belonging to the owner/operator of the multicopter fleet, or a contractor to thereof. Once thus placed, a Pod might be semi-permanently located on the power line, for extended periods of time, as necessitated by operational and commercial considerations, and possibly replaced or retrieved for maintenance purposes.

[Para 61 ] Each recharging cycle will consist of the following automated or remotely human-supervised steps, as illustrated in fig.1 7: Flight approach to the wire or to a predetermined location on the wire where, in embodiment B, a recharging pod has been deployed; inspection/verification of clear approach path; visual identification of the specific wire on which landing is to be performed or of the recharging pod itself, on the wire; alignment of multicopter's airframe with respect to the wire in a manner required to mechanically engage with it; verification (e.g. by magnetic sensing, or by wirelessly communicating with the recharging pod) of the existence of power in the line or in the anticipated magnetic field; a flight maneuver (e.g. descent) that will bring the multicopter to land and mechanically engage with the line or, directly on top of or next to the recharging pod; controlled discharge of static electricity between the line/pod and the multicopter, using multicopter's discharge wand; confirmation of adequate stable positioning and mechanical engagement with the line, or of electrical contact with the recharging pod; a reduction or cessation of power applied to flight rotors; commencement of battery charging; monitoring of charging levels and of stable positioning and engagement with the line or with the pod; Determination that recharging has concluded; re-powering of flight rotors, disengagement and take-off.

[Para 62] The recharging itself will take place, either via one or more coreless induction coils with which the multicopter is equipped, (as exemplified in figs 3, 4, 5 and 6) or, via one or more induction coils that are part of the recharging pod (e.g. as exemplified in figures 1 3, 1 4, 1 5 and 1 6). The arrangement of these coils will be such as to maximize the extent & intensity of the portion of the harvested magnetic field emanating from and surrounding the power line on which the multicopter has landed; while at the same time minimizing the weight of the coils. As is known from physics the magnetic field of a current carrying conductor is of circular direction, i.e. the field lines are tangential to any circle drawn in a plane perpendicular to the wire with its center coinciding with the conductor; thus the loops of the coil(s) should be within planes that are perpendicular to such field lines. Furthermore due to the inverse radial distance relationship in Ampere's law, the intensity of the field is strongest near the conductor itself, hence making it desirable to locate the coils (or as large as possible portion of their area) as close as possible to the conductor (= the power line on which the multicopter has landed).

[Para 63] An exemplary calcu lation illustrating the capability of such coils in said situation to recharge the batteries is presented henceforth. Multicopters typically use Lithium Polymer batteries, constructed of cells whose individual voltage is around 4 Volts, and which require at least a similar voltage to recharge. Thus it needs to be shown that a corresponding electromotive force (or EMF) can be induced in the situation u nder discussion. Faraday's law will be used to calculate the EMF; To use Faraday's law, the intensity of the magnetic field radiated from the utility power line should first be ascertained. This can be done using Ampere's law which states that the field of a current carrying wire is

B =≠^■ >i - With Uo being the vacuum permeability, or 4π x l O^-7 Tesla-

Meters/Ampere; I being the current in the wire, and r being the distance from the wire.

Taking 1= 1 000 amperes and r=0.1 meters we obtain B = 2 x 1 0^-3 Tesla.

[Para 64] Faraday's law now calculates the EMF induced in a coil bisecting a time-varying magnetic field as ε = -M X— [BA]

With N being the number of loops in the coil, B the magnetic field strength and A the area of the field bisected by the coil's loops. Taking

N = 1 00, A being fixed, and can be taken outside the derivative, an exemplary value being 0.3 meters², and the field itself B having a peak value of 2 x 1 0^-3 Tesla as ascertained above but time varying as a cosine function, with 50 Hertz frequency;

Resulting in _E = -IQO x 0.3 x (2 x 1 0^"3) x 2πχ50 = 1 8.8 volts (the 2πχ50 is from the derivative of Cos (2πί x t)). (note: This oversimplified calculation neglects several points, e.g. the spatially non-uniform intensity of B across area A of the coil, due to portions of the coil extending further away than 0.1 meters from the power line; Yet, it is also possible to use a coil with N> 1 00 loops, or to forego some of the 1 8.8 volts and use a lower voltage, etc.; The exemplary calculation merely indicates order-of-magnitude practicality of the invention).

[Para 65] Preferred embodiment A of such coil arrangement is exemplified in figs 2 , 3, 4 This arrangement focuses on maximizing the area of the coils at least as far as the airframe of the multicopter already extends (i.e. in order to house or support the motors and electronic components), with a relatively small nu mber of loops in each coil in order to minimize weight. Portions of the coils might also extend beyond the airframe itself.

[Para 66] Preferred embodiment B of such coil arrangement is exemplified in figs 2a, 1 3 and 1 6. This arrangement focuses on maximizing the area of the coils along the direction of the power line, with a relatively small number of loops in each coil in order to minimize both weight as well as mechanical projections of the coil (and the recharging pod in which it is contained) away from the power line. While mechanically robust, there would still be a desire to minimize additional mechanical loading on the power line, as well as to minimize risks of arcing (e.g. by creating a conductive path and/or projecting sharp edges that extend towards other wires and/or the towers that carry the power lines).

[Para 67] As illustrated by figs.4 &1 4, the spatial orientation of the coil(s) can be such that the area encompassed by the coil can be in any geometrical plane that contains the power line (i.e. rotational invariance around the power line), due to the circular symmetrical nature of the magnetic field lines around the power line. Specifically, this also includes a configuration (not illustrated) whereby the coil is situated in an upright position, i.e. vertical and perpendicular to the ground; specifically this might also include said oriented single coil situated in a position whereby it extends above or below the centerline of mu lticopter's body. [Para 68] A particu lar embodiment of this is a configuration whereby coils project symmetrically for a short distance (e.g. more than 5cm but less than one meter) on both sides of the power line, thereby potentially constituting a small mechanical "stage" that might assist in the landing of a multicopter on the power line.

[Para 69] Another embodiment of such coil arrangement is exemplified in figs 9 &1 5 whereby a coil with smaller cross section of loops is used (so that the loops extend only a very short distance in a radial direction away from the power line), yet with a larger number of loops in order to compensate for the smaller area (the two are interchangeable, as stated by Faraday's law; EmfocNA, A being the area of the inductor encompassing the magnetic field within a plane perpendicular to the magnetic field lines, and N being the number of loops of coil); the area and mass of the coil limited to the volume of space closest to the power line (thus intersecting the strongest portion of its magnetic field) and extending in an arc partially arou nd the power line.

[Para 70] One preferred embodiment of the overall mu lticopter arrangement is shown in Fig. l 1 , relying on a typical use case in which the rotors and their motors are mounted on long support structures extending out from multicopter's body. In this embodiment, said support structures are also used to support coils of a large area arrangement, said coils spanning the area out until (or close to) the outer edges of said rotor su pport structures. Fig.1 1 exemplifies such an arrangement based on 4 rotors, a corresponding number of support structures, and coils of rectangular-shaped area, yet this embodiment may also be implemented in arrangements with larger number of rotors, support structu res, and differently shaped coil areas.

[Para 71 ] An additional preferred embodiment might dispense with such above dedicated rotor support structures, instead of relying on mechanical arrangement of coils (or in particular the members on which the coils are wound) to carry the mechanical load of the rotors; In other words, the rotor motors are attached not to dedicated rotor support structures but to the (adequately strengthened) coil structures themselves, such coil structures extending out from the body of the multicopter as described in Fig. l i b, with the advantage of saving the weight of the dedicated rotor su pport structures. [Para 72] The mechanical engagement with the line will take place with the assistance of a Powerline Engagement Structu re. A preferred embodiment of the Powerline Engagement Structu re is illustrated in figures 6, 7 and 8, whereby this feature is implemented as an elongated slot, or trench, located in the lower surface of mu lticopter's body, that physically rests upon as well as grasps the line during the "landed" state of the multicopter (i.e. during a recharging stop). This embodiment assumes a landing from above, i.e. on top of the power line, providing several advantages with respect to alternative approaches which describe "hanging" on the line from below (e.g. as in US771 4536 to Silberg); Namely, not relying on an inductive harvesting device (e.g. coil) that is borne by the multicopter for mechanical suspension, too, thus saving the extra weight; of creating a firm engagement with the line (via a mechanical clasping of the line), that provides for stability & prevents accidental disengagement or unwanted movement (e.g. in condition of wind gusts, during a recharging stop); and of simplifying the landing approach and maneuver, in the case of flying altitudes that are above (i.e. higher than) the height at which power lines are suspended. Additional advantages (e.g. with respect to an embodiment described in US731 8564 to Marshall) are larger savings in weight due to the absence of an inductor core (typically iron - heavy) in a combined latch +core design as well as an additional solenoid mechanism for closing and opening of the latch. Moreover both above cited patents do not address the need to perform the recharging in a short period of time (in the interest of mission/equ ipment utilization efficiency) and consequently the need to include induction devices capable of generating a sufficiently high electro motive force (needed for fast charging) - not to mention doing so without incurring excessive weight.

[Para 73] An additional feature of the invention is the change of shape of the mu lticopter's body as a result of landing on a powerline (thusly situated beneath the centerline of multicopter's body as described), lowering the extremities of multicopter's airframe and correspondingly lowering the multicopter's center of gravity with respect to the powerline. The aim of this feature is to enhance the stability of the landed craft while on the power line, reducing the likeliness of falling off or moving (potentially affecting the charging process), for example due to a gust of wind. If the center of gravity of the multicopter is sufficiently lowered such that while in a landed, "recharging stop" position, it is located below the power line itself, a mechanical balance occurs that counteracts tipping forces (e.g. gusts of wind) and acts to stabilize the resting of the multicopter on the line. This is in addition to the mechanical grasping of the line described above; resulting in a stable and secure landed "recharging" state.

[Para 74] A preferred embodiment for this balancing feature, combined with a mechanical grasping of the powerline and not necessitating complex mechanics or dedicated actuators is described in figures 6, 7, 8, 1 0 and 1 1 . It comprises of dividing multicopter's mass/components/airframe (or part thereof) into two mechanically separate halves, connected by a hinge or hinge-like mechanism, that allows partial and limited rotational movement of the two halves around the geometrical center of the mu lticopter. [Para 75] While in flight, the u pward force exerted by the rotors (who are connected to the extremities of the airframe) keeps the two halves in an "un-rotated" (or "upwards rotated") position, for example within the same geometrical plane. However if the central portion of the multicopter mechanically rests on a thin long object (such as a power line) and power is removed/reduced from the rotors, the sides of the airframe will 'droop' (=rotate) downwards with respect to the central portion (that is resting on the power line). This change of shape creates both the balance-inducing lowering of center of gravity, as well as the mechanical grasping of the line on which the multicopter is resting, as described in fig.7.

[Para 76] An additional embodiment, or an additional feature to the embodiments described in figs 6, 7, 8, 1 0, 1 1 calls for portions of the multicopter's mass to be fixedly located at points in the airframe which are below the part of the airframe that rests on the power line. For example, the electrical batteries (typically a su bstantial part of the multicopter's weight), and/or any or part of the payload that the multicopter might be carrying, can be attached to the lower part of landing appendages (appearing as 1 1 0 in figure 1 ) or to that of dedicated downward-extending structures. This too wou ld lower the center of gravity with respect to the power line on which the multicopter lands, improving its balance and stability while in a landed "charging" state. [Para 77] An additional featu re of this invention is an "emergency line disengagement procedure". This feature relates to a situation whereby a multicopter has landed on a power line but is not able to take off and disengage from the line due to a technical fault of some sort. The risk of such possibility occurring presents a hazard of both equipment (multicopter) loss, as well as a maintenance hazard to the utility power company, due to the difficulty of retrieving such an object stranded on a power line. As part of the emergency line disengagement procedure, a pulse of current or a plurality of such pulses are internally applied by the multicopter's on-board controller (whether through a command sent externally by a hu man operator, or generated automatically as a preprogrammed emergency procedure) to one or more of said induction coils. Such a current-energized coil, in the presence of the magnetic field of the power line now feels a mechanical force as a resu lt of the interaction between the magnetic field surrounding the power line and the magnetic field generated by said cu rrent pulses in the coil; It will in effect become a "motor", and as such impart a corresponding force to the portion of the mu lticopter body to which it is attached, as illustrated in figs. 1 2 and 1 2a. More specifically, this feature relies on the non- uniformity of the magnetic field, which weakens with the reciprocal of the distance from the powerline. Referring by way of example to the rectangular coils as illustrated in fig. 1 1 , This force (and/or that creating by subsequent pu lses) have the effect of (1 ) disengaging the Powerline Engagement Structu re from the powerline, e.g. from an engaged state illustrated in fig. 7, to a disengaged state such as shown in fig. 6, by affecting a partial relative rotation of one half of multicopter's body with respect to the other half; (2) while having reverted to this state, multicopter's center of gravity also shifts upwards, towards and above the powerline, eliminating the stable balance on the multicopter on the line, and (3) creating a rotational inertia or torque of the multicopter around the power line, effectively knocking it off the line and allowing it to drop from the line towards the ground (where, for example, a retrieval net might be deployed to catch it in mid fall). Such a feature may be further enhanced by including a dedicated power source (e.g. capacitor and/or photovoltaic cell); by operating through a series of controlled (as opposed to one single) pulses; combined with real time sensing and analysis of direction of the fields with respect to multicopter's body, for example (but not limited to) timing the pulse(s) with respect to the momentary direction of the alternating magnetic field, to ensure effective disengagement and 'flipping' off the line.

[Para 78] In preceding discussions and descriptions of the invention, it should be noted that "Powerline" refers to an embodiment of the utility power line where each phase consists of a single conductor, e.g. a bundle of spun metal wires with a circular cross section and a total diameter of more than one but less than twelve centimeters; However it also refers to an embodiment of the utility power line consists of bundles of three or fou r separate (but mechanically connected and electrically identical) such wires. In said "bundle" type of utility power line, the overall (outer) diameter of the bundle is more than ten but less than fifty centimeters, constituting a wider landing support for the multicopter. In such cases the powerline engagement structure might either mechanically grasp a single wire out of the bundle; Or alternatively the hinge-like mechanism connecting multicopter's two halves operates such that when in the downward-rotated "landing" state, the two halves extend away from each other and from multicopter's geometrical center, thus forming a wider slot or trench in the center of the multicopters body, allowing said bundle to partially fit inside said slot/trench, facilitating a firm engagement with the bundle in the landed/"recharging" position.

[Para 79] In yet another preferred embodiment of the Perched Inductive Recharging Pod, the pod is also equipped with a control mechanism that selectively allows the initiation of recharging a "visiting" multicopter, based on positive identification of said multicopter's identity. The purpose of such a feature wou ld be to prevent misuse and un-approved power harvesting and recharging by multicopters or any other vehicles not approved to do so, e.g. not belonging to an organization that has a suitable commercial agreement with the powerline owner/operator. In such an embodiment, the recharge pod would also comprise of an identification mechanism, an onboard controller, a power switch and an internal power supply. The identification mechanism might for example be implemented using short-range means of wireless communication, such as active or passive RFID, Bluetooth, NFC or others, either of which will work with a corresponding/ matching transponder on the mu lticopters themselves; Or it might be based on visual means of identification, such as a combination of camera and visual coding (e.g. barcode); Or it might be based on a coding mechanism that operates via the circuit which is closed by the aforementioned contacting mechanism such as appears in figure 7; or other means of identification or a combination thereof. The onboard controller would fulfill the task of activating, processing and controlling the identification sequence. The power switch (such as a relay, an SCR, a power transistor, an IGBT or other switching device) would operate under the control of said onboard controller, it's task being to electrically connect the contacting mechanism to the coil itself (i.e. allow recharging), in the presence of having verified the identity of the visiting multicopter; or to disconnect them (prevent recharging) in the absence of such verification. The internal power supply's task is to provide power as needed to above said components of the recharging pod, relying on a small measure of energy harvested via the induction coil, from the power line itself; or from other means such as photovoltaic power. [Para 80] In yet another embodiment, the Perched Inductive Recharging Pod might also contain the battery recharging control circuitry (e.g. AC to DC conversion, charge sensing, charge controller), in order to allow further reduction of weight (the weight of said circuitry) from the multicopter itself.

In yet another embodiment, in order to improve the performance of an inductive recharging coil in terms of ratio of delivered power to weight of the coil, a material with a low as possible ratio of weight to conductivity should be selected. A known and often used material meeting this definition is Aluminum. Calcium and Sodium also have good conductivity: weight ratios (better than that of aluminum) but are environmentally unstable. However they can be used in conjunction with Aluminum in a "composite wire", for example a wire whose cross section is such that there is a core made of very light weight and high conductivity material, such as Calcium or Sodiu m, surrou nded by a "sheath" of slightly lower conductivity/weight material such as Alu minum, said sheath protecting said core from exposure to moisture and oxygen naturally existing in the environment while at the same time also contributing to the conductive cross-section of the wire. Alternatively, a specially engineered material such as Graphene, which possesses even significantly larger conductivity/weight ratio, might be used as the conducting medium for the loops of the coil. One preferred embodiment (in lieu of the processes requ ired to manufacture Graphene, which are of a "thin film deposition" nature, as opposed to processes used to manufacture metal wires - such as extrusion) is a "flat ribbon coil" whereby the conducting material (Graphene) has been deposited as a thin wide strip (for example more than 1 millimeter but less than 1 0 centimeters wide, and more than 1 micron but less than 1 millimeter thick) on a thin and flexible substrate (for example made of insu lating plastic, or paper) which is subsequently wound into a coil form.

Claims

WHAT IS CLAIMED IS:

1 . An apparatus for extending the operating range of small unmanned aerial vehicles, comprising: a body, a plurality of rotors each affixed to a motor, optical apparatus, sensors, antennas, landing appendages, electronic circuitry included within the body, batteries, radio transmitters and receivers, electronic devices, a utility power line, inductive coils formed by wire loops whose cross-sectional area encompasses part of the magnetic field produced around the utility power line by the electrical current it carries, an electrostatic discharge wand, and where coils are not present, the pod

2. The apparatus of claim 1 comprising a payload;

3. The apparatus of claim 1 may further comprise one or more fixed wings;

4. The apparatus of claim 1 further comprising a "Hinge-like" structure of aerial vehicle's body, allowing its two halves to droop lower than the line when landing on it to create a stable mechanical balance, and may further comprise an elongated slot, "powerline engagement structure", for gripping the line when the two halves droop at its sides;

5. The apparatus of claim 1 wherein, the spatial orientation of the coils may be such that the area encompassed by the coil is in any geometrical plane that contains the power line (rotational invariance around the power line) due to the circular symmetrical nature of the magnetic field lines around the power line;

6. A method for extending the operating range of small unmanned aerial vehicles, comprising: planning flight/mission routes alongside or in the vicinity of or intersecting with utility power lines, such that the flight/mission route includes "recharging stops" on said powerlines.

7. A method for extending the operating range of small unmanned aerial vehicles of claim 6, wherein said planning flight/mission routes is around or at the deployed recharging pods such that the flight/mission route includes "recharging stops" on said recharging pods.

8. A method for extending the operating range of small unmanned aerial vehicles of claims 646 & 7, wherein these stops are planned according to "Maximal Flight Segment" based on flight time & distance available to the aerial vehicles and its internal batteries, and flight conditions such as payload weight, weather conditions and the required destination.

9. The method of claim 88 wherein the path from aerial vehicles' originating/base station to required destination is divided into segments,

1 0. The method of claim 9 wherein each segment is equal to or shorter in length than the Maximal Flight Segment.

1 1 . The method of claim 1 01 0 wherein the point at which one segment ends and the next segment begin is located on a utility power line or on a previously deployed recharging pod, where aerial vehicle performs a recharging stop.

1 2. The method of claim 1 01 1 1 1 wherein the planning activity takes place based on a prepared map describing data such as paths of utility power lines, their type (operating voltage, number of phases carried), their mechanical structure (exact location of pylons, type and height of pylons, type and gauge of cables used, geometrical arrangement of the carried phases, etc.) and parameters related to commercial agreements with the owner/operator of utility power lines.

1 3. The method of claims 6-1 2 further comprises, software applications, data reporting, collection procedures, one or a plurality of databases for storing and managing flight and recharging-stop related data; such data comprising of, but not limited to, flight itineraries, recharging stops made, their timing, location, duration, and amount of power harvested during a recharging stop, allotment of landing locations and landing "windows" (time slots); recharging stop landing authorizations, sent in advance/ahead of time or in "real time'Vduring flight mission directly to aerial vehicle's control center, other billing related information, alternate routing/landing spot allocation; recharging stop queuing; emergency situation reports/instructions or other situations affecting planned recharging stops, any other data required to manage, regulate, transact, supervise and monitor the collective activity of aerial vehicle's relying on and making use of recharging stops on said power lines or on the charging pods which are deployed on utility power lines.

1 4. The method of claims 7-1 2, wherein the deployment of Perched Inductive Recharging Pods takes place under agreement with and in coordination with the entity that owns and/or operates the powerlines; locations of deployment is based on, but not limited to, business, ownership and operational needs, geography of logistical centers, flight paths restrictions (closed air spaces) or weather conditions; technology operational range limitations; expected scheduling of activity, and other considerations.

1 5. The method of claims 7-1 4, wherein the pods maybe deployed (perched and secured on the powerline) by several means, including but not limited to helicopters or linesmen (manually) belonging to the utility power company or a contractor to thereof; or by purposely designed aerial vehicles.

1 6. The method of claims 477-1 5, wherein a Pod maybe semipermanently located on a power line for extended periods of time and replaced or retrieved for maintenance purposes.

1 7. The method of claims 6-1 6, wherein each recharging cycle comprises automated or remotely human-supervised steps: flight approach to the wire or to a predetermined location on the wire or a recharging pod, inspection/verification of clear approach path, visual identification of the specific wire on which landing is to be performed or of the recharging pod on the wire, alignment of vehicle's airframe with respect to the wire in a manner required to mechanically engage with it, verification by magnetic sensing or by wirelessly communicating with the recharging pod of the existence of power in the line or in the anticipated magnetic field, a flight descent to land and mechanically engage with the line or, directly on top of or next to the recharging pod, controlled discharge of static electricity between the line/pod and the vehicle, using vehicle's discharge wand, confirmation of adequate stable positioning and mechanical engagement with the line, or of electrical contact with the recharging pod, a reduction or cessation of power applied to flight rotors, commencement of battery charging, monitoring of charging levels and of stable positioning and engagement with the line or with the pod, determination that recharging has concluded, re-powering of flight rotors, disengagement and take-off.

1 8. The method of claims 4776-1 7, wherein the recharging takes place, via one or more coreless induction coils or via one or more induction coils that are part of the recharging pod; the arrangement of these coils maximizes the extent & intensity of the portion of the harvested magnetic field emanating from and surrounding the power line on which the vehicle has landed, while at the same time minimizing the weight of the coils.

1 9. The method of claim 4771 21 41 51 61 71 81 8, wherein, achieving the low weight of the coils is by constructing their loops from materials with low weight/conductivity ratio, such as Calcium or Sodium; likely sheathed in an outer protective core made of lightweight metal; or by using especially engineered materials.

20. The method of claim 4771 21 41 51 61 71 81 8, wherein the loops of the coils are within planes that are perpendicular to field lines.

21 . The method of claim 4771 21 41 51 61 71 82020, wherein a configuration whereby coils project symmetrically for a short distance on both sides of the power line, constitute a small mechanical "stage" assisting in landing on the power line.

22. The method of claims 6 & 77, wherein coils with smaller cross section of loops are used so that the loops extend only a very short distance in a radial direction away from the power line, yet with a larger number of loops in order to compensate for the smaller area; the area and mass of the coil limited to the volume of space closest to the power line, intersecting the strongest portion of its magnetic field and extending in an arc partially around the power line.

23. The method of claims 6 & 77, wherein the rotors and their motors are mounted on long support structures extending out from vehicle's body; wherein said support structures are used to support coils of a large area arrangement, wherein said coils span the area out until (or close to) the outer edges of said rotor support structures.

24. The method of claim 4771 21 41 51 61 71 82021 222323, wherein, the rotor motors are attached not to dedicated rotor support structures but to the adequately strengthened coil structures themselves, thus saving the weight of the dedicated rotor support structures.

25. The method of claim 2424, wherein, the mechanical engagement with the line will take place with the assistance of a Powerline Engagement Structure implemented such as an elongated slot, or trench, located in the lower surface of vehicle's body, physically resting upon and grasping the line when landing from above during a recharging stop.

26. The method of claim 66 wherein, as part of the emergency line disengagement procedure, a pulse of current or a plurality of such pulses are internally applied by vehicle's on-board controller, either through a command sent externally by a human operator, or generated automatically as a pre-programmed emergency procedure, to one or more of said induction coils; such a current-energized coil, in the presence of the magnetic field of the power line receives a mechanical force as a result of the interaction between the magnetic field surrounding the power line and the magnetic field generated by said current pulses in the coil; It will in effect become a "motor" and impart a corresponding force to the portion of vehicle body to which it is attached; this force disengages the Powerline Engagement Structure from the powerline by affecting a partial relative rotation of one half of vehicle's body with respect to the other half; vehicle's center of gravity also shifts upwards, towards and above the powerline, eliminating the stable balance of vehicle on the line and creating a rotational inertia or torque of vehicle around the power line, effectively knocking it off the line and allowing it to drop from the line towards the ground, where means of retrieval may be deployed to catch it in mid fall; such feature may include a dedicated power source; wherein, by operating through a series of controlled pulses combined with real time sensing and analysis of direction of the fields with respect to vehicle's body, ensure effective disengagement and 'flipping' off the line

27. The method of claim 7 wherein, the pod is equipped with a control mechanism that selectively allows the initiation of recharging a "visiting" vehicle, based on positive identification of its identity; wherein, the recharge pod comprise: an identification mechanism, an onboard controller, a power switch and an internal power supply, wherein, the identification mechanism may be implemented using short-range means of wireless communication, working with a corresponding/ matching transponder based on the vehicle, or on visual means of identification, or on a coding mechanism operating via a circuit close by the contacting mechanism, or any other means of identification or a combination thereof; the onboard controller fulfills the task of activating, processing and controlling the identification sequence. The power switch operates under the control of said onboard controller to electrically connect the contacting mechanism to the coil allowing recharging if identification is verified, or disconnect preventing recharging in absence of verification; the internal power supply provides power to recharging pod, relying on a small measure of energy harvested via the induction coil from the power line or from any other means.