Electric propulsion systems for aircraft

Abstract

Increase the probability of continued safe operation of the aircraft. An electric propulsion system for an aircraft includes batteries, electric propulsion assemblies, and a power distribution circuit. Each battery is coupled to two or more of the electric propulsion assemblies via a respective one of the power distribution circuits. The electric propulsion assemblies are positioned on the aircraft and are operable to apply balanced forces to the aircraft in the event of a fault, such that the aircraft is not subjected to large changes in roll, pitch, and / or yaw.

Description

[Technical Field]

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 106,197, entitled "VTOL AIRCRAFT FAN TILTING MECHANISMS AND ARRANGEMENTS," filed October 27, 2020, and U.S. Non-Provisional Application No. 17 / 202,855, entitled "POWER DISTRIBUTION CIRCUITS FOR ELECTRICALLY POWERED AIRCRAFT," filed March 16, 2021, which are hereby incorporated by reference in their entireties for all purposes.

[0002] The described embodiments relate generally to electric propulsion systems for aircraft, and more particularly to an electric powered aircraft propulsion system including a power distribution circuit that provides balanced changes in thrust imparted to the aircraft resulting from one or more disturbances in the propulsion system. [Background technology]

[0003] Electrically powered aircraft may include propulsion systems that use multiple propulsion assemblies for reliability and maneuverability, however, the use of multiple propulsion assemblies increases the number of possible points of failure and the associated impact on stability and controllability. Summary of the Invention [Means for solving the problem]

[0004] An electric propulsion system for an aircraft is presented in which a balanced distribution of power among spatially distributed propulsion assemblies is used to ensure that stability and controllability impacts resulting from one or more fault conditions in the propulsion system do not induce large-scale changes in the roll, pitch, and / or yaw of the aircraft, thereby increasing the probability of continued safe operation of the aircraft.

[0005] In one aspect, an electric propulsion system for an aircraft includes batteries, electric propulsion assemblies, and a power distribution circuit. Each of the power distribution circuits couples one of the batteries to two or more of the electric propulsion assemblies. The electric propulsion assemblies coupled to the batteries are operable and positioned on the aircraft to provide a balanced force. For example, in some embodiments, the balanced force is balanced about a propulsion system balance point located within the limits of the aircraft's center of gravity (CG). In many embodiments, the propulsion system balance point is within a relatively small distance from the aircraft's center of gravity (CG), and the location of the CG can change due to variations in payload and fuel size and distribution. In many embodiments, each power distribution circuit is configured such that one or more fault conditions result in two or more of the electric propulsion assemblies ceasing to apply balanced forces to the aircraft, thereby ensuring resulting balanced stability and controllability effects that do not induce substantial changes in the roll, pitch, and / or yaw of the aircraft.

[0006] In some embodiments, the two or more electric propulsion assemblies coupled to the batteries include two electric propulsion assemblies diametrically opposed from one another about a propulsion system balance point of the aircraft, the propulsion system balance point being disposed within the center of gravity (CG) limits of the aircraft. The propulsion system balance point may be located near or on the center of gravity (CG) of the aircraft. In various embodiments, the electric propulsion assemblies include four electric propulsion assemblies operable and positioned to impart forces to the aircraft balanced about the propulsion system balance point. In some embodiments, the electric power propulsion system further includes contactors (e.g., electrical relay switches). Each of the contactors may be coupled between each respective battery and each respective isolated power distribution circuit. In various embodiments, at least one of the electric propulsion assemblies includes a primary controller, a primary winding, a redundant controller, and a redundant winding. The primary controller is coupled to the primary winding. The redundant controller is coupled to the redundant winding.

[0007] In some embodiments, a first one of the batteries is electrically coupled to a primary controller of the first propulsion assembly and a second one of the batteries is electrically coupled to a redundant controller of the first propulsion assembly. In various embodiments, the electric power propulsion system further includes fuses. Each of the fuses may couple two of the isolated power distribution circuits together such that some or all of the isolated power distribution circuits are electrically coupled together.

[0008] In another aspect, an electric propulsion system for an aircraft includes a first battery, a second battery, a first electric propulsion assembly, a second electric propulsion assembly, a third electric propulsion assembly, a fourth electric propulsion assembly, a first isolated power distribution circuit, and a second isolated power distribution circuit. The first electric propulsion assembly generates a first force. The second electric propulsion assembly generates a second force. The first force and the second force can be balanced about a propulsion system balance point located within a center of gravity limit for the aircraft. The third electric propulsion assembly generates a third force. The fourth electric propulsion assembly generates a fourth force. The third force and the fourth force can be balanced about the propulsion system balance point. The first isolated power distribution circuit couples the first battery to the first electric propulsion assembly and the second electric propulsion assembly. A second isolated power distribution circuit couples the second battery to the third electric propulsion assembly and the fourth electric propulsion assembly.

[0009] In some embodiments, the first electric propulsion assembly is mounted to a first wing of the aircraft, and the second electric propulsion assembly is mounted to a second wing of the aircraft. In various embodiments, the third electric propulsion assembly is mounted to the first wing of the aircraft, and the fourth electric propulsion assembly is mounted to the second wing of the aircraft. In some embodiments, the first isolated power distribution circuit and the second isolated power distribution circuit are primary isolated power distribution circuits. The electric propulsion system may further include a first redundant power distribution circuit and a second redundant power distribution circuit. The first redundant power distribution circuit may couple a third battery to the first electric propulsion assembly and the second electric propulsion assembly. The second redundant isolated power distribution circuit may couple a fourth battery to the third electric propulsion assembly and the fourth electric propulsion assembly.

[0010] In some embodiments, the first isolated power distribution circuit is coupled to a primary controller of the first electric propulsion assembly, the second isolated power distribution circuit is coupled to a primary controller of the second electric propulsion assembly, the first redundant isolated power distribution circuit is coupled to a redundant controller of the first electric propulsion assembly, and the second redundant isolated power distribution circuit is coupled to a redundant controller of the second electric propulsion assembly. In some embodiments, at least one of the first, second, third, and fourth electric propulsion assemblies includes a primary controller, a primary winding, a redundant controller, and a redundant winding. The primary controller is coupled to the primary winding. The redundant controller is coupled to the redundant winding. In various embodiments, the electric propulsion system further includes a fuse coupling the first isolated power distribution circuit to the second isolated power distribution circuit.

[0011] In another aspect, a method of powering an aircraft includes providing power to first and second electric propulsion assemblies via a first isolated power distribution circuit coupled to a first battery. The first electric propulsion assembly is mounted to the left wing of the aircraft and the second electric propulsion assembly is mounted to the right wing of the aircraft such that the first and second electric propulsion assemblies provide respective forces balanced about a propulsion system balance point disposed within a center of gravity limit for the aircraft. In various embodiments, the method of powering an aircraft further includes providing power to third and fourth electric propulsion assemblies via a second isolated power distribution circuit coupled to a second battery. The third electric propulsion assembly is operable and mounted to the left wing of the aircraft and the fourth electric propulsion assembly is operable and mounted to the right wing of the aircraft such that the third and fourth electric propulsion assemblies provide respective forces balanced about a propulsion system balance point.

[0012] In some embodiments, the first and second isolated power distribution circuits are primary isolated power distribution circuits. The method may further include (a) providing power to the first and second electric propulsion assemblies via a first redundant isolated power distribution circuit coupled to the third battery, and (b) providing power to the third and fourth electric propulsion assemblies via a second redundant isolated power distribution circuit coupled to the fourth battery. In various embodiments, the method uses contactors (e.g., electrical relay switches). Each of the contractors may be coupled between each respective battery and each respective isolated power distribution circuit. In some embodiments, at least one of the first, second, third, and fourth electric propulsion assemblies includes a primary controller, a primary winding, a redundant controller, and a redundant winding. The primary controller is coupled to the primary winding. The redundant controller is coupled to the redundant winding. In various embodiments, the method further uses a fuse coupling the first isolated power distribution circuit to the second isolated power distribution circuit.

[0013] In another aspect, an aircraft includes an airframe, a first propulsion assembly, a second propulsion assembly, a third propulsion assembly, a fourth propulsion assembly, a first battery, and a second battery. The airframe has a roll axis. The first propulsion assembly is coupled to the airframe and operable to generate a first lift force imparted to the airframe. The second propulsion assembly is coupled to the airframe and operable to generate a second lift force imparted to the airframe. The third propulsion assembly is coupled to the airframe and operable to generate a third lift force imparted to the airframe. The fourth propulsion assembly is coupled to the airframe and operable to generate a fourth lift force imparted to the airframe. The first battery is connected to the first propulsion assembly to provide power to the first propulsion assembly to generate the first lift force and is connected to the third propulsion assembly to provide power to the third propulsion assembly to generate the third lift force. The second battery is connected to the second propulsion assembly to power the second propulsion assembly to generate a second lift force and to the fourth propulsion assembly to power the fourth propulsion assembly to generate a fourth lift force. The first propulsion assembly, the second propulsion assembly, the third propulsion assembly, and the fourth propulsion assembly are spatially distributed. The first propulsion assembly and the third propulsion assembly are operable such that the first lift force and the third lift force are equal in magnitude and combine to generate a substantially zero roll moment imparted to the aircraft about the roll axis, such that a loss of power from the first battery to the first propulsion assembly and to the third propulsion assembly results in a substantially zero change in the roll moment imparted to the aircraft about the roll axis. The second propulsion assembly and the fourth propulsion assembly are operable such that the second lift force and the fourth lift force are equal in magnitude and combine to generate a substantially zero roll moment imparted to the aircraft about the roll axis, such that a loss of power supply from the second battery to the second propulsion assembly and to the fourth propulsion assembly results in a substantially zero change in the roll moment imparted to the aircraft about the roll axis.

[0014] The first propulsion assembly, the second propulsion assembly, the third propulsion assembly, and the fourth propulsion assembly may have any suitable spatial arrangement, for example, in some embodiments, the first propulsion assembly, the second propulsion assembly, the third propulsion assembly, and the fourth propulsion assembly are spatially arranged in a rectangular array.

[0015] In some embodiments, the aircraft further includes a first battery first switch, a second battery first switch, and a control system. The first battery first switch has a closed state in which the first battery is electrically connected to the first propulsion assembly and the third propulsion assembly. The first battery first switch has an open state in which the first battery is electrically disconnected from the first propulsion assembly and the third propulsion assembly. The second battery first switch has a closed state in which the second battery is electrically connected to the second propulsion assembly and the fourth propulsion assembly. The second battery first switch has an open state in which the second battery is electrically disconnected from the second propulsion assembly and the fourth propulsion assembly. The control system is configured to control operation of each of the first battery first switch and the second battery first switch. The control system causes the first battery first switch to be reconfigured from the closed state to the open state in response to a detected fault in the first propulsion assembly or the third propulsion assembly. The control system causes the first switch of the second battery to reconfigure from a closed state to an open state in response to a detected fault of the second propulsion assembly or the fourth propulsion assembly.

[0016] In some embodiments, the aircraft further includes a first battery second switch and a second battery second switch. The first battery second switch has a closed state in which the first battery is electrically connected to the second propulsion assembly and the fourth propulsion assembly. The first battery second switch has an open state in which the first battery is electrically disconnected from the second propulsion assembly and the fourth propulsion assembly. The second battery second switch has a closed state in which the second battery is electrically connected to the first propulsion assembly and the third propulsion assembly. The second battery second switch has an open state in which the second battery is electrically disconnected from the first propulsion assembly and the third propulsion assembly. The control system is further configured to control operation of each of the first battery second switch and the second battery second switch. The control system causes the first battery second switch to be reconfigured from the closed state to the open state in response to a detected fault in the second propulsion assembly or the fourth propulsion assembly. The control system causes a second switch of the second battery to reconfigure from a closed state to an open state in response to a detected fault in the first propulsion assembly or the third propulsion assembly.

[0017] In some embodiments, the first, second, third, and fourth propulsion assemblies use primary and secondary drive current controllers and associated drive coils. For example, in some embodiments, the first, second, third, and fourth propulsion assemblies each include a primary drive current controller, a primary drive coil, a secondary drive current controller, and a secondary drive coil. Each of the primary drive current controllers controls the supply of drive current to the associated primary drive coil. Each of the secondary drive current controllers controls the supply of drive current to the associated secondary drive coil. The primary drive current controller of each of the first and third propulsion assemblies is electrically connected to a first switch of the first battery to receive power from the first battery. The primary drive current controller of each of the second and fourth propulsion assemblies is electrically connected to a first switch of the second battery to receive power from the second battery. The secondary drive current controller of each of the first and third propulsion assemblies is electrically connected to the second switch of the second battery to receive power from the second battery, and the secondary drive current controller of each of the second and fourth propulsion assemblies is electrically connected to the second switch of the first battery to receive power from the first battery.

[0018] In some embodiments, the aircraft further includes a fifth propulsion assembly, a sixth propulsion assembly, a seventh propulsion assembly, an eighth propulsion assembly, a third battery, and a fourth battery. The fifth propulsion assembly is coupled to the airframe and operable to generate a fifth lift force imparted to the airframe. The sixth propulsion assembly is coupled to the airframe and operable to generate a sixth lift force imparted to the airframe. The seventh propulsion assembly is coupled to the airframe and operable to generate a seventh lift force imparted to the airframe. The eighth propulsion assembly is coupled to the airframe and operable to generate an eighth lift force imparted to the airframe. The third battery is connected to the fifth propulsion assembly to provide power to the fifth propulsion assembly to generate the fifth lift force and is connected to the seventh propulsion assembly to provide power to the seventh propulsion assembly to generate the seventh lift force. The fourth battery is connected to the sixth propulsion assembly to power the sixth propulsion assembly to generate a sixth lift force and to the eighth propulsion assembly to power the eighth propulsion assembly to generate an eighth lift force. The fifth propulsion assembly, the sixth propulsion assembly, the seventh propulsion assembly, and the eighth propulsion assembly are spatially distributed. The fifth propulsion assembly and the seventh propulsion assembly are operable such that the fifth lift force and the seventh lift force are equal in magnitude and combine to generate a substantially zero roll moment imparted to the aircraft about the roll axis, such that loss of power from the third battery to the fifth propulsion assembly and to the seventh propulsion assembly results in a substantially zero change in the roll moment imparted to the aircraft about the roll axis. The sixth propulsion assembly and the eighth propulsion assembly are operable such that the sixth lift force and the eighth lift force are equal in magnitude and combine to generate a substantially zero roll moment imparted to the aircraft about the roll axis such that a loss of power supply from the fourth battery to the sixth propulsion assembly and to the eighth propulsion assembly results in a substantially zero change in the roll moment imparted to the aircraft about the roll axis.In some embodiments, the sixth propulsion assembly, the seventh propulsion assembly, and the eighth propulsion assembly are spatially arranged in a rectangular array.

[0019] In some embodiments, the aircraft further includes a first switch for a first battery, a first switch for a second battery, a first switch for a third battery, a first switch for a fourth battery, and a control system. The first switch for the first battery has a closed state in which the first battery is electrically connected to the first propulsion assembly and the third propulsion assembly. The first switch for the first battery has an open state in which the first battery is electrically disconnected from the first propulsion assembly and the third propulsion assembly. The first switch for the second battery has a closed state in which the second battery is electrically connected to the second propulsion assembly and the fourth propulsion assembly. The first switch for the second battery has an open state in which the second battery is electrically disconnected from the second propulsion assembly and the fourth propulsion assembly. The first switch for the third battery has a closed state in which the third battery is electrically connected to the fifth propulsion assembly and the seventh propulsion assembly. The third battery first switch has an open state in which the third battery is electrically disconnected from the fifth and seventh propulsion assemblies. The fourth battery first switch has a closed state in which the fourth battery is electrically connected to the sixth and eighth propulsion assemblies. The fourth battery first switch has an open state in which the fourth battery is electrically disconnected from the sixth and eighth propulsion assemblies. The control system is configured to control the operation of each of the first battery first switch, the second battery first switch, the third battery first switch, and the fourth battery first switch. The control system causes the first battery first switch to be reconfigured from a closed state to an open state in response to a detected fault of the first propulsion assembly or the third propulsion assembly. The control system causes the second battery first switch to be reconfigured from a closed state to an open state in response to a detected fault of the second or fourth propulsion assembly.The control system causes the first switch of the third battery to be reconfigured from a closed state to an open state in response to a detected fault of the fifth propulsion assembly or the seventh propulsion assembly. The control system causes the first switch of the fourth battery to be reconfigured from a closed state to an open state in response to a detected fault of the sixth propulsion assembly or the eighth propulsion assembly.

[0020] In some embodiments, the aircraft further includes a first battery second switch, a second battery second switch, a third battery second switch, and a fourth battery second switch. The first battery second switch has a closed state in which the first battery is electrically connected to the second propulsion assembly and the fourth propulsion assembly. The first battery second switch has an open state in which the first battery is electrically disconnected from the second propulsion assembly and the fourth propulsion assembly. The second battery second switch has a closed state in which the second battery is electrically connected to the first propulsion assembly and the third propulsion assembly. The second battery second switch has an open state in which the second battery is electrically disconnected from the first propulsion assembly and the third propulsion assembly. The third battery second switch has a closed state in which the third battery is electrically connected to the sixth propulsion assembly and the eighth propulsion assembly. The third battery second switch has an open state in which the third battery is electrically disconnected from the sixth and eighth propulsion assemblies. The fourth battery second switch has a closed state in which the fourth battery is electrically connected to the fifth and seventh propulsion assemblies. The fourth battery second switch has an open state in which the fourth battery is electrically disconnected from the fifth and seventh propulsion assemblies. The control system is further configured to control operation of each of the first battery second switch, the second battery second switch, the third battery second switch, and the fourth battery second switch. The control system causes the first battery second switch to be reconfigured from a closed state to an open state in response to a detected fault of the second propulsion assembly or the fourth propulsion assembly. The control system causes the second battery second switch to be reconfigured from a closed state to an open state in response to a detected fault of the first or third propulsion assembly.The control system causes the third battery second switch to be reconfigured from a closed state to an open state in response to a detected fault of the sixth propulsion assembly or the eighth propulsion assembly. The control system causes the fourth battery second switch to be reconfigured from a closed state to an open state in response to a detected fault of the fifth propulsion assembly or the seventh propulsion assembly.

[0021] In some embodiments of the aircraft, each of the first propulsion assembly, the second propulsion assembly, the third propulsion assembly, the fourth propulsion assembly, the fifth propulsion assembly, the sixth propulsion assembly, the seventh propulsion assembly, and the eighth propulsion assembly includes a primary drive current controller, a primary drive coil, a secondary drive current controller, and a secondary drive coil. Each of the primary drive current controllers controls the supply of drive current to an associated primary drive coil. Each of the secondary drive current controllers controls the supply of drive current to an associated secondary drive coil. The primary drive current controller of each of the first propulsion assembly and the third propulsion assembly is electrically connected to a first switch of the first battery to receive power from the first battery. The primary drive current controller of each of the second propulsion assembly and the fourth propulsion assembly is electrically connected to a first switch of the second battery to receive power from the second battery. The primary drive current controller of each of the fifth and seventh propulsion assemblies is electrically connected to a first switch of the third battery to receive power from the third battery. The primary drive current controller of each of the sixth and eighth propulsion assemblies is electrically connected to a first switch of the fourth battery to receive power from the fourth battery. The secondary drive current controller of each of the first and third propulsion assemblies is electrically connected to a second switch of the second battery to receive power from the second battery. The secondary drive current controller of each of the second and fourth propulsion assemblies is electrically connected to a second switch of the first battery to receive power from the first battery. The secondary drive current controller of each of the fifth and seventh propulsion assemblies is electrically connected to a second switch of the fourth battery to receive power from the fourth battery. The secondary drive current controller of each of the sixth propulsion assembly and the eighth propulsion assembly is electrically connected to the third battery second switch for receiving power from the third battery.

[0022] For a better understanding of the nature and advantages of the present disclosure, reference should be made to the following description and accompanying figures. It should be understood, however, that each of the figures is provided for purposes of illustration only and is not intended as a definition of the limits of the scope of the present disclosure. Also, as a general rule, and unless otherwise apparent from the description, when elements in different figures use the same reference numerals, the elements are generally either identical, or at least similar, in function or purpose. [Brief explanation of the drawings]

[0023] [Figure 1A] FIG. 1 is a simplified isometric view of an electrically powered aircraft in a vertical flight configuration according to an embodiment of the present disclosure. [Figure 1B] FIG. 1 is a simplified isometric view of an electrically powered aircraft in a horizontal flight configuration according to an embodiment of the present disclosure. [Figure 2] FIG. 1C is a simplified schematic diagram of an electric propulsion system including six isolated primary power distribution circuits and six isolated redundant power distribution circuits for the electronically powered aircraft shown in FIGS. 1A and 1B. [Figure 3] FIG. 3 is a schematic diagram of the electric propulsion system shown in FIG. 2 illustrating the effects of a battery failure. [Figure 4] FIG. 3 is a schematic diagram of the electric propulsion system shown in FIG. 2 illustrating the effects of a contactor failure or a short circuit in the power distribution bus. [Figure 5] FIG. 3 is a schematic diagram of the electric power propulsion system shown in FIG. 2, illustrating the effects of a shorted inverter or motor winding. [Figure 6] FIG. 3 is a schematic diagram of the electric propulsion system shown in FIG. 2 showing the effects of a suddenly stopped motor. [Figure 7] FIG. 1C is a simplified schematic diagram of an electric propulsion system including six isolated primary power distribution circuits and no redundant power distribution circuits for the electronically powered aircraft shown in FIGS. 1A and 1B. [Figure 8]FIG. 1C is a simplified schematic diagram of an electric power propulsion system including six primary power distribution circuits and six redundant power distribution circuits coupled together via fuses to form a common power bus for the electronically powered aircraft shown in FIGS. 1A and 1B. [Figure 9] FIG. 1C is a simplified schematic diagram of an electric propulsion system including six isolated primary power distribution circuits coupled together via fuses to form a common power bus for the electronically powered aircraft shown in FIGS. 1A and 1B. DETAILED DESCRIPTION OF THE INVENTION

[0024] Systems and techniques disclosed herein generally relate to electrically powered vertical takeoff and landing (VTOL) aircraft. More specifically, the systems and techniques disclosed herein relate to an electrically powered propulsion system and method for a VTOL aircraft, in which power from batteries is distributed to multiple propulsion assemblies such that one or more faults in the electric propulsion system do not result in destabilizing changes in the roll, pitch, and / or yaw of the aircraft. In many embodiments, each battery powers a subset of the aircraft's propulsion assemblies, via associated power distribution circuitry, that are operable to generate and apply counter-balancing thrust, such that one or more fault conditions in the propulsion systems do not result in the loss of corresponding counter-balancing thrust, thereby producing any destabilizing changes in the roll, pitch, and / or yaw of the aircraft. Various inventive embodiments, including methods, processes, systems, devices, and the like, are described herein.

[0025] To better appreciate the features and aspects of the power distribution system for an electric-powered aircraft according to the present disclosure, further background to the present disclosure is provided in the sections that follow by discussing specific implementations of an electric-powered vertical take-off and landing (VTOL) aircraft according to examples of the present disclosure. These examples are for illustrative purposes only, and the power distribution system may be used in types of electric-powered vehicles other than those depicted herein.

[0026] Several illustrative embodiments will now be described with reference to the accompanying drawings, which form a part of this specification. The following description merely provides examples and is not intended to limit the scope, applicability, or configuration of the present disclosure. Rather, the following description of the embodiments will provide those skilled in the art with an enabling description for implementing one or more embodiments. It will be understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the present disclosure. In the following description, for purposes of explanation, specific details are set forth in order to provide a thorough understanding of certain inventive embodiments. It will be apparent, however, that various embodiments may be practiced without these specific details. The figures and descriptions are not intended to be limiting. The words "exemplary" or "exemplary" are used herein to mean "serving as an example, instance, or illustration." Any embodiment or design described herein as "exemplary" or "illustrative" is not necessarily to be construed as preferred or advantageous over other embodiments or designs.

[0027] 1A and 1B depict simplified isometric views of an electrically powered VTOL aircraft 100 with twelve tilting electronic propulsion assemblies 105(1)-105(12), according to an embodiment of the present disclosure. More specifically, FIG. 1A depicts the aircraft 100 in a vertical flight configuration, and FIG. 1B depicts the aircraft 100 in a horizontal flight configuration.

[0028] As shown in FIGS. 1A and 1B , in some embodiments, aircraft 100 may be configured to carry one or more passengers and / or cargo and may be automatically and / or remotely controlled (e.g., may not require an onboard pilot to operate the aircraft). In the illustrated example, aircraft 100 includes a fuselage 110, which may include a cabin section for carrying passengers and / or cargo. Propulsion assemblies 105(1)-105(12) may be mounted on opposite ends of booms 115. One or more booms 115 may be coupled to each wing 120, 125 of aircraft 100 to enable aircraft 100 to have any number of propulsion assemblies 105. For example, each wing 120, 125 may include three booms 115, each including a pair of tilting electronic propulsion assemblies 105 mounted thereon.

[0029] 1A and 1B using three mutually perpendicular coordinate axes, X, Y, and Z, at the intersection of which is a propulsion system balance point 130 for the aircraft 100. In many embodiments, the propulsion system balance point 130 is located within the center of gravity limits of the aircraft 100 and may be located within a relatively small distance from the aircraft center of gravity (CG). As is known, the location of an aircraft's center of gravity (CG) typically varies due to differences in the quantity and location of payload details (e.g., fuel, crew, luggage, etc.). Variations in the location of the center of gravity (CG) relative to the aircraft 100 during operation of the aircraft 100 are typically constrained by applicable airworthiness regulations such that the location of the center of gravity (CG) relative to the aircraft 100 remains within prescribed limits. In many embodiments, the propulsion system balance point 130 is located at a suitable location within the specified location limits of the center of gravity (CG) to minimize changes in aircraft roll, pitch, and / or yaw resulting from one or more propulsion system faults, as further described herein.

[0030] Aircraft 100 has six degrees of freedom, including forces Fx, Fy, and Fz in the directions of each coordinate axis and moments Mx, My, and Mz about each coordinate axis. Aircraft 100 includes a left wing 125 opposite a right wing 120, both of which are attached to fuselage 110. In this embodiment, propulsion assemblies 105 are distributed along each wing 120, 125 in a manner that there are an equal number on the left wing 125, an equal number on the right wing 120, an equal number at the front of each wing, and an equal number at the rear of each wing, thereby resulting in an equal distribution of propulsion assemblies 105 about propulsion system balance point 130. Equal distribution of propulsion assemblies 105 about a propulsion system balance point 130 located within defined location limits of the center of gravity (CG), combined with the power distribution techniques described herein, can be used to minimize changes in aircraft roll, pitch, and / or yaw resulting from one or more propulsion system failures, as further described herein.

[0031] Aircraft 100 includes a power distribution system (not shown in FIGS. 1A and 1B ) that delivers power from the batteries to propulsion assemblies 105, as described in more detail below. In many embodiments, the power distribution system includes power distribution circuits. Each of the power distribution circuits distributes power from at least one battery to at least two of the propulsion assemblies 105 that are balanced about propulsion system balance point 130 such that, when a corresponding fault condition of the propulsion system occurs, the forces imparted to the aircraft from the propulsion assemblies that are interrupted as a result of the fault condition are balanced or substantially balanced about propulsion system balance point 130, thereby resulting in a balanced reduction in the forces imparted to aircraft 100. For example, in the illustrated embodiment, propulsion assemblies 105(1) and 105(12) may be supplied with power through one power distribution circuit, and propulsion assemblies 105(6) and 105(7) may be supplied with power through a different power distribution circuit.

[0032] 1A , if any power distribution circuit fails, the aircraft 100 will experience a change in force along the Z axis (Fz), and the resulting changes in other forces or moments (Fx, Fy, Mx, My, or Mz) will be relatively small due to the proximity of the propulsion system balance point 130 to the aircraft's center of gravity (CG), thereby reducing the resulting roll, pitch, and / or yaw of the aircraft 100 compared to conventional propulsion systems. Other examples of balanced propulsion assemblies are, among others: 2, 11; 5, 8; 3, 10; 4, 9; 1, 6, 7, 12; 2, 5, 8, 11, and 3, 4, 9, 10. Those skilled in the art will recognize that the number and locations of electronic propulsion assemblies 105 are not limited to those illustrated in FIGS. 1A-1B and that the aircraft may include fewer or more propulsion assemblies located at other locations on the aircraft, etc.

[0033] FIG. 2 illustrates a simplified power distribution system 200 for the aircraft 100 illustrated in FIGS. 1A and 1B. As shown in FIG. 2, power distribution system 200 includes twelve isolated power distribution circuits 205(1)-205(12), each coupled to one of six batteries 220(1)-220(6) through contactors 215(1)-215(12), as described in more detail below, and arranged to supply power to two or more propulsion assemblies 105 balanced about propulsion system balance point 130 (see FIGS. 1A and 1B). More specifically, in this particular embodiment, there are six primary isolated power distribution circuits 205(1)-205(6) and six redundant isolated power distribution circuits 205(7)-205(12). Each power distribution circuit 205 supplies power to a balanced pair of propulsion assemblies.

[0034] For example, primary power distribution circuit 205(1) is coupled to battery 1 220(1) through contactor 215(1) and supplies power to balanced propulsion assemblies 105(1) and 105(12). As shown in FIGURES 1A and 1B, propulsion assemblies 105(1) and 105(12) are balanced about propulsion system balance point 130 (see FIGURES 1A and 1B) because propulsion system 105(1) is the same distance along port wing 125 (e.g., the +Y-axis) from propulsion system balance point 130 as propulsion system 105(12) is along starboard wing 120 from the center of gravity, resulting in a balanced moment Mx about the X-axis. Furthermore, propulsion system 105(1) is the same distance forward (along the +X axis) of propulsion system balance point 130 as propulsion system 105(12) is aft of the CG (along the -X axis), resulting in a balancing moment My about the Y axis. A balanced propulsion assembly may also be referred to as "diametrically opposed" about propulsion system balance point 130.

[0035] In this particular embodiment, each propulsion system 105 includes a primary controller 225(1)-225(12) coupled to a primary winding 230(1)-230(12) and a redundant controller 235(1)-235(12) coupled to a redundant winding 240(1)-240(12). The primary windings 230(1)-230(12) and the redundant windings 240(1)-240(12) each couple power to a respective shaft 245(1)-245(12), which rotates a respective propeller 250(1)-250(12). The primary controller 225 and primary winding 230 are electrically isolated from the redundant controller 235 and the redundant winding 240 so that if one controller or winding fails, the shaft 245 still receives half the power from the other controller and winding.

[0036] For example, propulsion system 105(1) may receive half power from battery 220(1) through primary power distribution circuit 205(1), which is coupled to primary controller 225(1) and primary winding 230(1), and half power from battery 220(6) through redundant power distribution circuit 205(12), which is coupled to redundant controller 235(1) and redundant winding 240(1). Thus, if battery 220(1) fails, propulsion system 105(1) may still receive half power from battery 6 220(6). Because propulsion assemblies 105(1) and 105(12) are balanced, the power to each propulsion system may be the same. In some embodiments, control or computing system 255 may be used to compensate and boost the power provided to propulsion assemblies 105(1) and 105(12) from Battery 6 220(6) to compensate for the loss of half power due to a failure of Battery 1 220(1).

[0037] In a similar manner, battery 2 220(2) supplies power to propulsion assemblies 105(2) and 105(11) through primary power distribution circuit 205(2), battery 3 220(3) supplies power to propulsion assemblies 105(3) and 105(10) through primary power distribution circuit 205(3), battery 4 220(4) supplies power to propulsion assemblies 105(4) and 105(9) through primary power distribution circuit 205(4), battery 5 220(5) supplies power to propulsion assemblies 105(5) and 105(8) through primary power distribution circuit 205(5), and battery 6 220(6) supplies power to propulsion assemblies 105(6) and 105(7) through primary power distribution circuit 205(6).

[0038] In this embodiment, there are also six redundant power distribution circuits 205(7)-205(12). Battery 1 220(1) supplies power to propulsion assemblies 105(6) and 105(7) through redundant power distribution circuit 205(7), battery 2 220(2) supplies power to propulsion assemblies 105(5) and 105(8) through redundant power distribution circuit 205(8), battery 3 220(3) supplies power to propulsion assemblies 105(4) and 105(9) through redundant power distribution circuit 205(9), battery 4 220(4) supplies power to propulsion assemblies 105(3) and 105(10) through redundant power distribution circuit 205(10), battery 5 220(5) supplies power to propulsion assemblies 105(2) and 105(11) through redundant power distribution circuit 205(5), and battery 6 220(6) supplies power to propulsion assemblies 105(1) and 105(12) through redundant power distribution circuit 205(6). Other arrangements of primary and redundant power distribution circuits and propulsion assemblies are within the scope of this disclosure, as will be recognized by those skilled in the art with the benefit of this disclosure.

[0039] As shown in FIG. 2 , each primary and redundant power distribution circuit 205 is coupled to a respective battery 220 via a respective contactor 215(1)-215(12). That is, each contactor 215 controls the power provided to a balanced pair of propulsion assemblies 105 via its respective power distribution circuit 205. In some embodiments, each contactor 215 is an electromechanical relay, while in other embodiments, the contactor may be a different device, including, but not limited to, one or more solid-state switches. In various embodiments, the contactors 215 may be controlled by a current sensing circuit that senses current flowing into or out of each battery 220. When the current reaches a predetermined threshold, the contactor 215 may open, severing the connection between the battery 220 and its respective power distribution circuit 205. Each power distribution circuit 205, represented in FIG. 2 by a single line, represents a DC circuit including at least a power conductor and a ground conductor. In some embodiments, a common ground conductor may be used for more than one power distribution circuit 205. In various embodiments, contactors 215 may be located between only the positive or ground conductor and battery 220, while in other embodiments, the contactors may be located between both the power and ground conductors. In further embodiments, fuses may be used in place of or in addition to contactors 215.

[0040] In some embodiments, control system 255 may be coupled to controllers 225, 235, contactors 215, and / or batteries 220 to control one or more functions of power distribution system 200, as described in more detail below. In one embodiment, control system 255 may make adjustments in one or more controllers 225, 235 to maintain batteries 220 at a similar state of charge. More specifically, in some embodiments, one or more batteries 220 may be aging (e.g., being older or having experienced more discharge cycles) and have a reduced charge capacity, and / or one or more batteries may be replaced with freshly charged batteries, causing the batteries to have unequal states of charge. Control system 255 may receive information from each battery 220 related to that battery's state of charge and adjust the operation of one or more controllers 225, 235 to adjust the power drawn from each battery.

[0041] In some embodiments, each controller 225, 235 includes an inverter that receives DC power from the power distribution circuit 205 and converts the DC power to AC power supplied to the motor windings 230, 240 in terms of torque, rpm, blade pitch, etc. In various embodiments, each propulsion system 105 includes an AC motor; however, in other embodiments, the propulsion system may include multiple motors coupled to a single shaft, and in further embodiments, may be a DC motor. In some embodiments, such as shown in FIGS. 1A and 1B, the aircraft 100 is overactuated, i.e., the aircraft has more propulsion assemblies 105 (e.g., 12) than degrees of freedom (e.g., 6); therefore, the control system 255 may adjust numerous combinations of the controllers 225, 235 to discharge individual batteries 220 faster or slower than others to maintain an equal state of charge among all of the batteries. Thus, the control system 255 may use forces and moments (e.g., Fx, Fy, Fz, Mx, My, Mz) and the state of charge of the battery 220 as inputs and may output commands to the controllers 225, 235 to optimize the state of charge and power usage.

[0042] In some embodiments, a balanced arrangement of the propulsion assemblies 105 on the aircraft 100 allows for even discharge of the batteries 220 during crosswinds and other conditions. For example, as shown in FIG. 1A , a crosswind approaching from the left (e.g., from propulsion assemblies 105(1) and 105(7) toward propulsion assemblies 105(6) and 105(12)) causes a decrease in power draw from propulsion assemblies 105(1) and 105(7) and an increase in power draw from propulsion assemblies 105(6) and 105(12). However, as shown in FIG. 2 , a crosswind approaching from the left (e.g., from propulsion assemblies 105(1) and 105(7) toward propulsion assemblies 105(6) and 105(12)) causes a decrease in power draw from propulsion assemblies 105(1) and 105(7) and an increase in power draw from propulsion assemblies 105(6) and 105(12). 105(1) and 105(12) are coupled to the same battery (e.g., batteries 220(1) and 220(6)), so that the increased power draw of 105(12) offsets the decreased power draw of 105(1), so that batteries 220(1) and 220(6) maintain a relatively similar rate of discharge as batteries 220(2) through 220(5). Similarly, propulsion assemblies 105(6) and 105(7) are balanced.

[0043] In some embodiments, one or more diodes may be coupled in series with the power distribution circuit so that current can only flow out of the battery and not into it to protect the power distribution system in the event of a shorted battery. In other embodiments, the power distribution system enables regenerative charging, where the propulsion assemblies generate energy (e.g., during descent) and transfer power to the battery.

[0044] 3-6 illustrate the operation of power distribution system 200 during example failure modes. While not shown, other failure modes and responses to failure modes by the power distribution system are within the scope of this disclosure. FIG. 3 illustrates power distribution system 200 as shown in FIG. 2; however, in FIG. 3, battery 220(1) is shown as having failed. As shown in FIG. 3, failed battery 220(1) causes contactor 215(1) and contactor 215(7) to open, such that power is no longer supplied to propulsion system 105(1) via primary controller 225(1), to propulsion system 105(12) via primary controller 225(12), to propulsion system 105(6) via redundant controller 235(6), and to propulsion system 105(7) via redundant controller 235(7). Thus, propulsion assemblies 105(1), 105(6), 105(7), and 105(12) may receive half the power they received before the failure of battery 220(1).

[0045] As described above, in some embodiments, control system 255 may detect a fault, open contactors 215(1), 215(7), and immediately increase power from battery 220(6) to propulsion assemblies 105(1), 105(6), 105(7), and 105(12) to restore 100% power to the aircraft. Alternatively, due to the balanced nature of power distribution circuit 205, control system 255 may increase power to propulsion assemblies 105(1) and 105(12) to compensate for the entire power loss from battery 220(1), or alternatively, increase power to propulsion assemblies 105(6) and 105(7). Alternatively, control system 255 may take more complex actions to compensate for the fault, such as increasing power from battery 220(2) to propulsion assemblies 105(2) and 105(11). Those skilled in the art having the benefit of this disclosure will recognize many different options that the controller may use to compensate for the loss of battery 220(1).

[0046] FIG. 4 illustrates the power distribution system 200 shown in FIG. 2; however, in FIG. 4, battery contactor 215(1) has failed and / or a short circuit exists in power distribution circuit 205(1). As shown in FIG. 3, contactor 215(1) may be opened when a fault is detected, which disconnects power from power distribution circuit 205(1) that supplies power to balanced propulsion assemblies 105(1) and 105(12). In this manner, power to aircraft 100 is reduced in a balanced manner. Because contactor 215(1) disconnects the connection between the fault and battery 220(1), the battery may still supply power to power distribution circuit 205(7) and propulsion assemblies 105(6) and 105(7) via contactor 215(7).

[0047] Figure 5 illustrates the power distribution system 200 shown in Figure 2; however, in Figure 5, primary controller 225(1) and / or primary winding 230(1) have failed. As shown in Figure 5, contactor 215(1) can be opened when a fault is detected, which cuts power from power distribution circuit 205(1) and from battery 220(1) to primary controller 225(1) and primary winding 230(1). Propulsion system 105(1) can still receive half power from battery 220(6) via redundant power distribution circuit 205(12).

[0048] FIG. 6 illustrates the power distribution system 200 shown in FIG. 2; however, in FIG. 6, shaft 245(1) of first propulsion system 105(1) has stopped suddenly. As shown in FIG. 6, contactor 215(1) may be opened when a fault is detected, which disconnects power from power distribution circuit 205(1) and from battery 220(1). Similarly, contactor 215(12) may be opened, which disconnects power from redundant power distribution circuit 205(12) and from battery 220(6). Due to the balanced arrangement, opening contactors 215(1), 215(12) also results in a complete loss of power delivered to propulsion system 105(12). Because the loss of power to propulsion assemblies 105(1) and 105(12) is balanced, aircraft 100 will not rotate in response to the fault and will only lose altitude or speed. The control system 255 can compensate for disturbances in a myriad of ways, as explained above.

[0049] FIG. 7 illustrates a power distribution system 700 that is similar to power distribution system 200 shown in FIG. 2; however, in FIG. 7, redundant power distribution circuits 205(7)-205(12) have been eliminated. As shown in FIG. 7, each propulsion system 705(1)-705(12) has only a primary controller 225 and a primary winding 230. Primary power distribution circuits 205(1)-205(6) still supply power to propulsion assemblies 105 in a balanced manner. However, if a primary power distribution circuit 205(1)-205(6) fails, there is no redundant power distribution circuit to continue supplying power to propulsion assembly 705. For example, if battery 220(1) fails, contactor 215(1) opens and balanced propulsion assemblies 705(1) and 705(12) cease operation. Control system 255 may compensate by increasing power from battery 220(6) to balanced propulsion assemblies 705(6) and 705(7), or by taking a myriad of other actions.

[0050] Figure 8 illustrates a power distribution system 800 that is similar to the power distribution system 200 shown in Figure 2; however, in Figure 8, each primary power distribution circuit 205(1) through 205(6) and each redundant power distribution circuit 205(7) through 205(12) is integrally coupled with a fuse 805(1) through 805(10). As shown in Figure 8, a first fuse 805(1) couples the first and second primary power distribution circuits 205(1), 205(2), respectively, a second fuse 805(2) couples the second and third primary power distribution circuits 205(2), 205(3), respectively, and similar connections are made for the third through fifth fuses, 805(3) through 805(5), respectively. Similarly, the redundant power distribution circuits 205(7) to 205(12) are integrally coupled with a sixth fuse 805(6) that couples the first and second redundant power distribution circuits 205(7), 205(8), respectively, and a seventh fuse 805(7) that couples the second and third redundant power distribution circuits 205(8), 205(9), respectively, and similar connections are made to the eighth through tenth fuses, 805(8) to 805(10), respectively.

[0051] Fuse 805 electrically couples all power distribution circuits 205 together, resulting in the power distribution circuits having a common voltage level. This arrangement allows for uniform discharge of batteries 220 and power sharing along a common bus. In the event of a shorted battery fault, such as battery 220(2), first fuse 805(1), second fuse 805(2), sixth fuse 805(6), and seventh fuse 805(7) blow, which isolates first battery 220(1) from batteries 220(3)-220(6). Essentially, the fault causes the faulted power distribution circuit to become "islanded" as a result of fuses on either side of the fault blowing. In some embodiments, contactors may be included, as shown in FIG. 2, to disconnect each battery from the primary and / or redundant power distribution circuits.

[0052] FIG. 9 illustrates a power distribution system 900 that is similar to the power distribution system 800 shown in FIG. 8 and the power distribution system 200 shown in FIG. 2; however, in FIG. 9, the redundant power distribution circuits 205(7)-205(12) have been eliminated. As shown in FIG. 9, each propulsion assembly 905 has only a primary controller 225 and a primary winding 230. The primary power distribution circuits 205(1)-205(6) are each coupled together via fuses 805(1)-805(5) to form a common bus and supply power to the propulsion assemblies 905 in a balanced manner. The fuses 805 result in all power distribution circuits 205 having a common voltage level because they are all electrically coupled together. This arrangement allows for uniform discharge of the batteries 220 and power sharing along the common bus. Similar to Figure 8, in the event of a fault, the failed power distribution circuit and / or battery is "islanded" by blowing one or more fuses on either side of the fault. In some embodiments, contactors may be included, as shown in Figure 2, to disconnect each battery from the primary and / or redundant power distribution circuit.

[0053] Although aircraft 100 (see FIG. 1 ) is described and illustrated as one particular configuration of aircraft, embodiments of the present disclosure are suitable for use with a variety of aircraft. For example, any aircraft that uses two or more electronic propulsion assemblies may be used with embodiments of the present disclosure. In some applications, embodiments of the present disclosure are particularly well suited for use with aircraft carrying one or more people due to the need for reliability; however, the power distribution systems disclosed herein are not limited to “manned” aircraft and may be used in any “manned” and “unmanned” aircraft of any size.

[0054] For simplicity, various electrical components of the power distribution system, such as capacitors, current sensing circuits, controller details, processor communication buses, memory, storage devices, and other components, are not shown in the figures.

[0055] In the foregoing specification, embodiments of the present disclosure have been described with reference to numerous specific details that may vary from implementation to implementation. Accordingly, the specification and drawings should be considered in an illustrative rather than a restrictive sense. The sole and exclusive indication of the scope of the present disclosure, and what is intended by the applicant to be the scope of the present disclosure, is the set of claims issuing from this application, in the specific form in which such claims issue, including any subsequent amendments, and the literal and equivalent scope of such claims. Specific details of individual embodiments may be combined in any suitable manner without departing from the spirit and scope of the embodiments of the present disclosure.

[0056] Additionally, spatial relationship terms such as "bottom" or "top," and the like, may be used to describe the relationship of an element and / or feature to another element and / or feature, for example, as illustrated in the figures. It will be understood that spatial relationship terms are intended to encompass different orientations of the device in use and / or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, an element described as having a "bottom" surface may be oriented "above" the other element or feature. The device may be oriented in other ways (e.g., rotated 90 degrees or at other orientations), and the spatial relationship descriptors used herein may be interpreted accordingly.

[0057] With reference to the accompanying figures, components that may include memory (e.g., control or computing system 255, controllers 225, 235, etc.) may include non-transitory machine-readable media. As used herein, the terms “machine-readable medium” and “computer-readable medium” refer to any storage medium that participates in providing data that causes a machine to operate in a specific manner. In the examples provided herein above, various machine-readable media may be involved in providing instructions / code to a processor and / or other device for execution. Additionally, or alternatively, machine-readable media may be used to store and / or transport such instructions / code. In many implementations, computer-readable media are physical and / or tangible storage media. Such media may take many forms, including, but not limited to, non-volatile media, volatile media, and transmission media. Common forms of computer-readable media include, for example, magnetic and / or optical media, punch cards, paper tape, any other physical medium with a pattern of holes, RAM, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), Flash EPROM, any other memory chip or cartridge, a carrier wave as described hereinafter, or any other medium from which a computer can read instructions and / or code.

[0058] The methods, systems, and devices discussed herein are illustrative. Various embodiments may omit, substitute, or add various procedures or components as appropriate. For example, features described in a particular embodiment may be combined in various other embodiments. Different aspects and elements of the embodiments may be combined in a similar manner. Various components of the diagrams provided herein may be embodied in hardware and / or software. Also, technology evolves, and therefore many of the elements are illustrative, without limiting the scope of the disclosure to those specific examples.

[0059] It has proven convenient at times, principally for reasons of common usage, to refer to such signals as bits, information, values, elements, symbols, characters, variables, terms, numbers, numerals, or the like. It should be understood, however, that all of these or similar terms are to be associated with appropriate physical quantities and are merely convenient labels. Unless specifically stated otherwise, and as will be apparent from the above discussion, it will be recognized that throughout this specification, discussion utilizing terms such as "processing," "calculating," "computing," "determining," "determining," "identifying," "associating," "measuring," "performing," or the like refers to the actions or processes of a specific apparatus such as a special purpose computer, controller, or similar special purpose electronic computing device. Therefore, in the context of this specification, a special purpose computer or similar special purpose electronic computing device is capable of manipulating or transforming signals, which are typically represented as physical electronic, electrical, or magnetic quantities, in the memories, registers, or other information storage, transmission, or display devices of the special purpose computer or similar special purpose electronic computing device.

[0060] Those skilled in the art will recognize that the information and signals used to convey the messages described herein may be represented using any of a variety of different technologies and techniques. For example, the data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0061] The terms "and," "or," and "one / or," as used herein, can have a variety of meanings that are also expected to depend, at least in part, on the context in which such terms are used. Typically, "or," when used to link a list, such as A, B, or C, is intended to mean A, B, and C, as used herein, in an inclusive sense, as well as A, B, or C, as used herein in an exclusive sense. Additionally, the term "one or more," as used herein, may be used to describe any feature, structure, or characteristic in the singular, or may be used to describe any combination of features, structures, or characteristics. However, it should be noted that this is merely an illustrative example, and claimed subject matter is not limited to this example. Furthermore, the term "at least one of," when used to relate a list, such as A, B, or C, may be interpreted to mean any combination of A, B, and / or C, such as A, B, C, AB, AC, BC, AA, AAB, ABC, AABBCCC, etc.

[0062] References throughout this specification to "one example," "one example," "a particular example," or "exemplary implementation" mean that the individual feature, structure, or characteristic described in connection with the feature and / or example may be included in at least one feature and / or example of the claimed subject matter. Thus, appearances of the phrases "in one example," "one example," "in a particular example," "in a particular implementation," or other similar phrases in various places throughout this specification do not necessarily all refer to the same feature, example, and / or limitation. Furthermore, individual features, structures, or characteristics may be combined in one or more examples and / or features.

[0063] In the foregoing detailed description, numerous specific details have been set forth to provide a thorough understanding of the claimed subject matter. However, it will be understood by those skilled in the art that the claimed subject matter may be practiced without these specific details. In other instances, methods and apparatuses that would be known by those skilled in the art have not been described in detail so as not to obscure the claimed subject matter. Therefore, it is intended that the claimed subject matter not be limited to the particular examples disclosed, but that such claimed subject matter may include all aspects falling within the scope of the appended claims and equivalents of those aspects.

[0064] For implementations involving firmware and / or software, the methodologies may be implemented with modules (e.g., procedures, functions, etc.) that perform the functions described herein. Any machine-readable medium tangibly embodying instructions may be used in implementing the methodologies described herein. For example, software code may be stored in a memory and executed by a processor unit. The memory may be implemented within the processor unit or external to the processor unit. As used herein, the term "memory" may refer to any type of long-term, short-term, volatile, non-volatile, or other memory and should not be limited to any particular type of memory or number of memories or the type of medium on which the memory is stored.

[0065] If implemented in firmware and / or software, the functions may be stored as one or more instructions or code on a computer-readable storage medium. Examples include computer-readable media encoded with a data structure and computer-readable media encoded with a computer program. Computer-readable media include physical computer storage media. A storage medium may be any available medium that can be accessed by a computer. By way of example, and not limitation, such computer-readable media may include RAM, ROM, EEPROM, compact disc read-only memory (CD-ROM) or other optical disk storage, magnetic disk storage, semiconductor storage, or other storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer; disk and disc, as used herein, include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs; disks typically reproduce data magnetically, while discs reproduce data optically with a laser. Combinations of the above should also be included within the scope of computer-readable media.

[0066] In addition to being stored on a computer-readable storage medium, the instructions and / or data may be provided as signals on a transmission medium included in a communications device. For example, the communications device may include a transceiver having signals indicating instructions and data. The instructions and data are configured to cause one or more processors to implement the functions outlined in the claims. That is, the communications device includes a transmission medium with signals indicating information for performing the disclosed functions. At a first time, the transmission medium included in the communications device may include a first portion of information for performing the disclosed functions, while at a second time, the transmission medium included in the communications device may include a second portion of information for performing the disclosed functions.

Claims

1. 1. An electric propulsion system for an aircraft, comprising: Multiple batteries and a plurality of electric propulsion assemblies; a plurality of isolated power distribution circuits, each coupling a battery of the plurality of batteries to two or more electric propulsion assemblies of the plurality of electric propulsion assemblies, the plurality of isolated power distribution circuits being positioned on the aircraft such that the two or more electric propulsion assemblies impart a balanced force to the aircraft; An electric propulsion system comprising:

2. 2. The electric powered propulsion system of claim 1, wherein the balanced forces imparted to the aircraft are balanced about a propulsion system balance point located within a center of gravity (CG) limit of the aircraft.

3. 10. The electric powered propulsion system of claim 1, wherein the two or more electric propulsion assemblies comprise two electric propulsion assemblies diametrically opposed from each other about a propulsion system balance point located within a center of gravity (CG) limit of the aircraft.

4. 10. The electric powered propulsion system of claim 1, wherein the two or more electric propulsion assemblies comprise four electric propulsion assemblies arranged to impart forces to the aircraft balanced about a propulsion system balance point located within a center of gravity (CG) limit of the aircraft.

5. The electric power propulsion system of claim 1 , further comprising a plurality of contactors, each contactor coupled between a respective battery and a respective isolated power distribution circuit.

6. an electric propulsion system of at least one of the plurality of electric propulsion assemblies including a primary controller coupled to a primary winding and a redundant controller coupled to a redundant winding; 10. The electric power propulsion system of claim 1.

7. 10. The electric power propulsion system of claim 1, wherein a first battery of the plurality of batteries is electrically coupled to a primary controller of a first propulsion system and a second battery of the plurality of batteries is electrically coupled to a redundant controller of the first propulsion system.

8. 2. The electric power propulsion system of claim 1, further comprising a plurality of fuses, each fuse coupling two isolated power distribution circuits of the plurality of isolated power distribution circuits together such that the plurality of isolated power distribution circuits are electrically coupled together.

9. 1. An electric propulsion system for an aircraft, comprising: a first battery and a second battery; a first electric propulsion assembly that generates a first force and a second electric propulsion assembly that generates a second force, the first force and the second force being balanced about a center of gravity of the aircraft; a third electric propulsion assembly generating a third force and a fourth electric propulsion assembly generating a fourth force, the third force and the fourth force being balanced about the center of gravity of the aircraft; a first isolated power distribution circuit coupling the first battery to the first electric propulsion assembly and the second electric propulsion assembly; a second isolated power distribution circuit coupling the second battery to the third electric propulsion assembly and the fourth electric propulsion assembly; and An electric propulsion system comprising:

10. 10. The electric power propulsion system of claim 9, wherein the first electric propulsion assembly is mounted to a first wing of the aircraft and the second electric propulsion assembly is mounted to a second wing of the aircraft.

11. 11. The electric power propulsion system of claim 10, wherein the third electric propulsion assembly is mounted to the first wing of the aircraft and the fourth electric propulsion assembly is mounted to the second wing of the aircraft.

12. The first insulated power distribution circuit and the second insulated power distribution circuit are primary insulated power distribution circuits, and the power distribution circuits are a first redundant isolated power distribution circuit coupling a third battery to the first electric propulsion assembly and the second electric propulsion assembly; a second redundant isolated power distribution circuit coupling a fourth battery to the third electric propulsion assembly and the fourth electric propulsion assembly; and The electric power propulsion system of claim 9 further comprising:

13. the first isolated power distribution circuit and the second isolated power distribution circuit are coupled to a primary controller of the first electric propulsion assembly and a primary controller of the second electric propulsion assembly, respectively; the first redundant isolated power distribution circuit and the second redundant isolated power distribution circuit are coupled to a redundant controller of the first electric propulsion assembly and a redundant controller of the second electric propulsion assembly, respectively; 13. The electric power propulsion system of claim 12.

14. 10. The electric power propulsion system of claim 9, wherein at least one electric propulsion assembly of the first, second, third, and fourth electric propulsion assemblies includes a primary controller coupled to a primary winding and a redundant controller coupled to a redundant winding.

15. The electric power propulsion system of claim 9 , further comprising a fuse coupling the first isolated power distribution circuit to the second isolated power distribution circuit.

16. 1. A method of powering an aircraft, comprising: providing electrical power to a first electric propulsion assembly and a second electric propulsion assembly via a first isolated power distribution circuit coupled to a first battery, the first electric propulsion assembly being mounted on a left wing of the aircraft and the second electric propulsion assembly being mounted on a right wing of the aircraft, the first electric propulsion assembly and the second electric propulsion assembly being operable to provide respective lift forces balanced about a centerline of the aircraft; providing electrical power to a third electric propulsion assembly and a fourth electric propulsion assembly via a second isolated power distribution circuit coupled to a second battery, the third electric propulsion assembly being mounted on a left wing of the aircraft and the fourth electric propulsion assembly being mounted on a right wing of the aircraft, the third electric propulsion assembly and the fourth electric propulsion assembly being operable to provide respective lift forces balanced about the centerline of the aircraft; A method comprising:

17. the first insulated power distribution circuit and the second insulated power distribution circuit are primary insulated power distribution circuits, and the method includes: providing power to the first electric propulsion assembly and the second electric propulsion assembly via a first redundant isolated power distribution circuit coupled to a third battery; providing power to the third electric propulsion assembly and the fourth electric propulsion assembly via a second redundant isolated power distribution circuit coupled to a fourth battery; 17. The method of claim 16, further comprising:

18. 17. The method of claim 16, further comprising contactors, each contactor coupled between one of the first battery and the second battery and one of the first isolated power distribution circuit and the second isolated power distribution circuit.

19. 17. The method of claim 16, wherein at least one of the first, second, third, and fourth electric propulsion assemblies includes a primary controller coupled to a primary winding and a redundant controller coupled to a redundant winding.

20. 17. The method of claim 16, further comprising a fuse coupling the first isolated power distribution circuit to the second isolated power distribution circuit.

21. An aircraft, an airframe having a roll axis; a first propulsion assembly coupled to the airframe and operable to generate a first lift force imparted to the airframe; a second propulsion assembly coupled to the vehicle body and operable to generate a second lift force imparted to the vehicle body; and a third propulsion assembly coupled to the vehicle and operable to generate a third lift force imparted to the vehicle; and a fourth propulsion assembly coupled to the vehicle body and operable to generate a fourth lift force imparted to the vehicle body; and a first battery connected to the first propulsion assembly to provide power to the first propulsion assembly to generate the first lift, and connected to the third propulsion assembly to provide power to the third propulsion assembly to generate the third lift; a second battery connected to the second propulsion assembly to power the second propulsion assembly to generate the second lift, and connected to the fourth propulsion assembly to power the fourth propulsion assembly to generate the fourth lift; Equipped with the first propulsion assembly, the second propulsion assembly, the third propulsion assembly, and the fourth propulsion assembly are spatially distributed; the first propulsion assembly and the third propulsion assembly are operable such that a loss of a supply of electrical power from the first battery to the first propulsion assembly and the third propulsion assembly results in a substantially zero roll moment being imparted to the aircraft about the roll axis, and the first lift force and the third lift force are equal in magnitude and combine to generate a substantially zero roll moment being imparted to the aircraft about the roll axis; the second propulsion assembly and the fourth propulsion assembly are operable such that a loss of power supply from the second battery to the second propulsion assembly and the fourth propulsion assembly results in a substantially zero roll moment being imparted to the aircraft about the roll axis, and such that the second lift force and the fourth lift force are equal in magnitude and combine to generate a substantially zero roll moment being imparted to the aircraft about the roll axis.

22. 22. The aircraft of claim 21, wherein the first propulsion assembly, the second propulsion assembly, the third propulsion assembly, and the fourth propulsion assembly are spatially arranged in a rectangular array.

23. a first battery first switch having a closed state in which the first battery is electrically connected to the first propulsion assembly and the third propulsion assembly and an open state in which the first battery is electrically disconnected from the first propulsion assembly and the third propulsion assembly; a second battery first switch having a closed state in which the second battery is electrically connected to the second propulsion assembly and the fourth propulsion assembly and an open state in which the second battery is electrically disconnected from the second propulsion assembly and the fourth propulsion assembly; a control system configured to control operation of each of the first battery first switch and the second battery first switch, the control system causing the first battery first switch to reconfigure from the closed state to the open state in response to a detected fault of the first propulsion assembly or the third propulsion assembly, and causing the second battery first switch to reconfigure from the closed state to the open state in response to a detected fault of the second propulsion assembly or the fourth propulsion assembly; 22. The aircraft of claim 21, further comprising:

24. a first battery second switch having a closed state in which the first battery is electrically connected to the second propulsion assembly and the fourth propulsion assembly and an open state in which the first battery is electrically disconnected from the second propulsion assembly and the fourth propulsion assembly; a second switch for a second battery having a closed state in which the second battery is electrically connected to the first propulsion assembly and the third propulsion assembly and an open state in which the second battery is electrically disconnected from the first propulsion assembly and the third propulsion assembly; and Furthermore, the control system is further configured to control operation of each of a second switch of the first battery and a second switch of the second battery; the control system causes a second switch of the first battery to reconfigure from the closed state to the open state in response to a detected fault of the second propulsion assembly or the fourth propulsion assembly; 24. The aircraft of claim 23, wherein the control system causes a second switch of the second battery to reconfigure from the closed state to the open state in response to a detected fault of the first propulsion assembly or the third propulsion assembly.

25. each of the first propulsion assembly, the second propulsion assembly, the third propulsion assembly, and the fourth propulsion assembly comprises a primary drive current controller, a primary drive coil, a secondary drive current controller, and a secondary drive coil, each of the primary drive current controllers controlling the supply of drive current to the associated primary drive coil, and each of the secondary drive current controllers controlling the supply of drive current to the associated secondary drive coil; the primary drive current controller of each of the first propulsion assembly and the third propulsion assembly is electrically connected to a first switch of the first battery to receive power from the first battery; the primary drive current controller of each of the second propulsion assembly and the fourth propulsion assembly is electrically connected to a first switch of the second battery to receive power from the second battery; the secondary drive current controller of each of the first propulsion assembly and the third propulsion assembly is electrically connected to a second switch of the second battery to receive power from the second battery; the secondary drive current controller of each of the second propulsion assembly and the fourth propulsion assembly is electrically connected to a second switch of the first battery to receive power from the first battery.

25. The aircraft of claim 24.

26. a fifth propulsion assembly coupled to the vehicle and operable to generate a fifth lift force imparted to the vehicle; and a sixth propulsion assembly coupled to the vehicle and operable to generate a sixth lift force imparted to the vehicle; and a seventh propulsion assembly coupled to the vehicle and operable to generate a seventh lift force imparted to the vehicle; and an eighth propulsion assembly coupled to the vehicle body and operable to generate an eighth lift force imparted to the vehicle body; and a third battery connected to the fifth propulsion assembly to power the fifth propulsion assembly to generate the fifth lift, and connected to the seventh propulsion assembly to power the seventh propulsion assembly to generate the seventh lift; a fourth battery connected to the sixth propulsion assembly to power the sixth propulsion assembly to generate the sixth lift, and connected to the eighth propulsion assembly to power the eighth propulsion assembly to generate the eighth lift; and Furthermore, the fifth propulsion assembly, the sixth propulsion assembly, the seventh propulsion assembly, and the eighth propulsion assembly are spatially distributed; the fifth propulsion assembly and the seventh propulsion assembly are operable such that a loss of power supply from the third battery to the fifth propulsion assembly and the seventh propulsion assembly results in a substantially zero roll moment being imparted to the aircraft about the roll axis, and the fifth lift force and the seventh lift force are equal in magnitude and combine to generate a substantially zero roll moment being imparted to the aircraft about the roll axis; 22. The aircraft of claim 21, wherein the sixth propulsion assembly and the eighth propulsion assembly are operable such that the sixth lift force and the eighth lift force are equal in magnitude and combine to generate a substantially zero roll moment imparted to the aircraft about the roll axis such that a loss of power supply from the fourth battery to the sixth propulsion assembly and the eighth propulsion assembly results in a substantially zero roll moment imparted to the aircraft about the roll axis.

27. 27. The aircraft of claim 26, wherein the fifth propulsion assembly, the sixth propulsion assembly, the seventh propulsion assembly, and the eighth propulsion assembly are spatially arranged in a rectangular array.

28. a first battery first switch having a closed state in which the first battery is electrically connected to the first propulsion assembly and the third propulsion assembly and an open state in which the first battery is electrically disconnected from the first propulsion assembly and the third propulsion assembly; a second battery first switch having a closed state in which the second battery is electrically connected to the second propulsion assembly and the fourth propulsion assembly and an open state in which the second battery is electrically disconnected from the second propulsion assembly and the fourth propulsion assembly; a third battery first switch having a closed state in which the third battery is electrically connected to the fifth propulsion assembly and the seventh propulsion assembly and an open state in which the third battery is electrically disconnected from the fifth propulsion assembly and the seventh propulsion assembly; a fourth battery first switch having a closed state in which the fourth battery is electrically connected to the sixth propulsion assembly and the eighth propulsion assembly and an open state in which the fourth battery is electrically disconnected from the sixth propulsion assembly and the eighth propulsion assembly; a control system configured to control operation of each of a first switch of the first battery, a first switch of the second battery, a first switch of the third battery, and a first switch of the fourth battery; Furthermore, the control system causes a first switch of the first battery to reconfigure from the closed state to the open state in response to a detected fault of the first propulsion assembly or the third propulsion assembly; the control system causes a first switch of the second battery to reconfigure from the closed state to the open state in response to a detected fault of the second propulsion assembly or the fourth propulsion assembly; the control system causes a first switch of the third battery to reconfigure from the closed state to the open state in response to a detected fault of the fifth propulsion assembly or the seventh propulsion assembly; 27. The aircraft of claim 26, wherein the control system causes a first switch of the fourth battery to reconfigure from the closed state to the open state in response to a detected fault of the sixth propulsion assembly or the eighth propulsion assembly.

29. a first battery second switch having a closed state in which the first battery is electrically connected to the second propulsion assembly and the fourth propulsion assembly and an open state in which the first battery is electrically disconnected from the second propulsion assembly and the fourth propulsion assembly; a second switch for a second battery having a closed state in which the second battery is electrically connected to the first propulsion assembly and the third propulsion assembly and an open state in which the second battery is electrically disconnected from the first propulsion assembly and the third propulsion assembly; a third battery second switch having a closed state in which the third battery is electrically connected to the sixth propulsion assembly and the eighth propulsion assembly and an open state in which the third battery is electrically disconnected from the sixth propulsion assembly and the eighth propulsion assembly; a fourth battery second switch having a closed state in which the fourth battery is electrically connected to the fifth propulsion assembly and the seventh propulsion assembly and an open state in which the fourth battery is electrically disconnected from the fifth propulsion assembly and the seventh propulsion assembly; and Furthermore, the control system is further configured to control operation of each of the first battery second switch, the second battery second switch, the third battery second switch, and the fourth battery second switch; the control system causes a second switch of the first battery to reconfigure from the closed state to the open state in response to a detected fault of the second propulsion assembly or the fourth propulsion assembly; the control system causes a second switch of the second battery to reconfigure from the closed state to the open state in response to a detected fault of the first propulsion assembly or the third propulsion assembly; the control system causes the third battery second switch to reconfigure from the closed state to the open state in response to a detected fault of the sixth propulsion assembly or the eighth propulsion assembly; 29. The aircraft of claim 28, wherein the control system causes the fourth battery second switch to reconfigure from the closed state to the open state in response to a detected fault of the fifth propulsion assembly or the seventh propulsion assembly.

30. each of the first propulsion assembly, the second propulsion assembly, the third propulsion assembly, the fourth propulsion assembly, the fifth propulsion assembly, the sixth propulsion assembly, the seventh propulsion assembly, and the eighth propulsion assembly comprises a primary drive current controller, a primary drive coil, a secondary drive current controller, and a secondary drive coil, each of the primary drive current controllers controlling the supply of drive current to the associated primary drive coil and each of the secondary drive current controllers controlling the supply of drive current to the associated secondary drive coil; the primary drive current controller of each of the first propulsion assembly and the third propulsion assembly is electrically connected to a first switch of the first battery to receive power from the first battery; the primary drive current controller of each of the second propulsion assembly and the fourth propulsion assembly is electrically connected to a first switch of the second battery to receive power from the second battery; the primary drive current controller of each of the fifth propulsion assembly and the seventh propulsion assembly is electrically connected to a first switch of the third battery to receive power from the third battery; the primary drive current controller of each of the sixth propulsion assembly and the eighth propulsion assembly is electrically connected to a first switch of the fourth battery to receive power from the fourth battery; the secondary drive current controller of each of the first propulsion assembly and the third propulsion assembly is electrically connected to a second switch of the second battery to receive power from the second battery; the secondary drive current controller of each of the second propulsion assembly and the fourth propulsion assembly is electrically connected to a second switch of the first battery to receive power from the first battery; the secondary drive current controller of each of the fifth propulsion assembly and the seventh propulsion assembly is electrically connected to the fourth battery second switch for receiving power from the fourth battery; the secondary drive current controller of each of the sixth propulsion assembly and the eighth propulsion assembly is electrically connected to the third battery second switch for receiving power from the third battery.

30. The aircraft of claim 29.

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