Failure-resilient redundant fly-by-wire system

Abstract

The present invention provides an aircraft fly-by-wire control system and a related vehicle electrical system. The vehicle electrical system includes a bus arrangement, the bus arrangement includes a plurality of buses; a first control module, the first control module is coupled to a first subgroup of the buses; a second control module, the second control module is coupled to a second subgroup of the buses; and a third control module is coupled to a third subgroup of the buses. The first subgroup includes a first bus, a second bus, a third bus and a fourth bus, the second subgroup includes a third bus, a fourth bus, a fifth bus and a sixth bus, and the third subgroup includes a first bus, a second bus, a fifth bus and a sixth bus.

Description

Technical Field

[0001] The subject matter described herein relates generally to aircraft systems and, more particularly, embodiments of the subject matter relate to redundant fly-by-wire systems configured to achieve failure resiliency in vertical take-off and landing (VTOL) aircraft. Background Art

[0002] In some modern aircraft, traditional mechanical flight control systems have been replaced by electrically controlled actuators (commonly referred to as fly-by-wire). Instead of mechanical connections between cockpit controls and flight control surfaces, propulsion systems, and / or lift systems, electrical signals are used to transmit the movement of cockpit controls to controllers associated with appropriate flight control components or systems. For safety reasons, fly-by-wire systems typically employ redundancy to ensure that they can operate after a failure; however, this typically increases the number of required wiring and interfaces. For smaller aircraft, such as taxis or other urban air mobility (UAM) vehicles, it is typically desirable to minimize the amount of wiring, weight, and associated costs. However, completely avoiding redundant wiring may unexpectedly result in failure modes that are not suitable for unconventional aircraft such as vertical take-off and landing (VTOL) aircraft. Therefore, it is also desirable to minimize the impact on the availability of flight control components in response to a fault condition. Other desired features and characteristics will become apparent from the subsequent specific embodiments and the appended claims, taken in conjunction with the accompanying drawings and the aforementioned technical field and background technology. Summary of the invention

[0003] A vehicle electrical system suitable for use with an aircraft is provided. An exemplary fly-by-wire electrical system suitable for use with a vehicle includes: a bus arrangement including a plurality of buses; a first control module coupled to a first subset of the plurality of buses, the first subset including a first bus, a second bus, a third bus, and a fourth bus; a second control module coupled to a second subset of the plurality of buses, the second subset including a third bus, a fourth bus, a fifth bus, and a sixth bus; and a third control module coupled to a third subset of the plurality of buses, the third subset including a first bus, a second bus, a fifth bus, and a sixth bus. The first subset, the second subset, and the third subset are different from each other. A controller of a flight control component is coupled to two of the six buses. In one or more exemplary embodiments, the bus is implemented as a controller area network (CAN) bus. In one or more exemplary embodiments, the flight control component is a component of an aircraft having vertical take-off and landing (VTOL) capability, such as, for example, a lift fan. In some embodiments, the controller of the flight control component is not connected to a bus pair of the first bus and the second bus, the third bus and the fourth bus, or the fifth bus and the sixth bus.

[0004] Other desirable features and characteristics of the method and system will become apparent from the subsequent detailed description and the appended claims, considered in conjunction with the accompanying drawings and the foregoing background. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Embodiments of the subject matter will be described below in conjunction with the following drawings, wherein like numerals represent like elements, and:

[0006] Figure 1 is a block diagram illustrating a fly-by-wire system suitable for use with an aircraft, according to one or more exemplary embodiments; and

[0007] Figure 2 Shows the suitability with Figure 1 A vertical take-off and landing (VTOL) aircraft that is used in conjunction with a fly-by-wire control system. DETAILED DESCRIPTION

[0008] The following detailed description is merely exemplary in nature and is not intended to limit the subject matter of its application and uses. Furthermore, there is no intention to be bound by any theory presented in the preceding background, summary or the following detailed description.

[0009] Embodiments of the subject matter described herein relate to electronically controlled vehicle systems. For purposes of explanation, the subject matter is described herein primarily in the context of an aircraft that uses electrical signals to control flight control components, however the subject matter is not necessarily limited to use with aircraft and can be implemented in an equivalent manner for other types of vehicles (e.g., automobiles, marine vessels, etc.).

[0010] Figure 1An exemplary embodiment of a fly-by-wire system 100 suitable for use with an aircraft is shown. The fly-by-wire system 100 includes a plurality of communication buses 101, 102, 103, 104, 105, 106, a plurality of flight control modules 110, 112, 114, and a plurality of controllers 120, 122, 124, 126, 128, 130 associated with a plurality of flight control components. In the illustrated embodiment, a first flight control module 110 is coupled to a first subset of the buses (e.g., buses 101, 102, 103, and 104), a second flight control module 112 is coupled to a second subset of the buses (e.g., buses 103, 104, 105, and 106), and a third flight control module 114 is coupled to a third subset of the buses (e.g., buses 101, 102, 105, and 106), wherein each of the bus subsets is unique, special, or otherwise different from one another. In other words, the flight control modules 110, 112, 114 are not coupled to a common subgroup of the buses 101, 102, 103, 104, 105, 106, and since there is no physical electrical connection to the corresponding isolated bus, each of the flight control modules 110, 112, 114 is isolated from at least two of the buses 101, 102, 103, 104, 105, 106 (for example, the first flight control module 110 is isolated from the fifth bus 105 and the sixth bus 106, the second flight control module 112 is isolated from the first bus 101 and the second bus 102, and the third flight control module 114 is isolated from the third bus 103 and the fourth bus 104).

[0011] It should be noted that although Figure 1 A fly-by-wire system 100 is shown including six buses 101, 102, 103, 104, 105, 106 and three flight control computers 110, 112, 114, but it should be understood that the subject matter described herein is not necessarily limited to any particular number of buses, flight control computers, or controllers 120, 122, 124, 126, 128, 130. For example, other embodiments may include more than three flight control computers, and / or more than one controller per flight control component, as may be desired to achieve the level of redundancy or reliability required for a particular application.

[0012] In an exemplary embodiment, the controllers 120, 122, 124, 126, 128, 130 manage flight control components that provide lift, propulsion, and / or attitude control for the aircraft, such as flight control surface actuators, lift fans, motors, or similar flight control components that can adjust or otherwise affect the position or orientation of the aircraft. In this regard, in one or more embodiments, each controller 120, 122, 124, 126, 128, 130 manages a unique flight control component (or set of flight control components) that is different from those managed by other controllers 120, 122, 124, 126, 128, 130. That is, other embodiments may employ redundancy, wherein more than one controller 120, 122, 124, 126, 128, 130 is capable of operating common flight control components. In an exemplary embodiment, each controller 120, 122, 124, 126, 128, 130 is coupled to a particular or unique subset of the buses 101, 102, 103, 104, 105, 106 relative to the other controllers 120, 122, 124, 126, 128, 130. In one or more embodiments, the buses 101, 102, 103, 104, 105, 106 are logically grouped or paired with each other (e.g., a first pairing of the first bus 101 and the second bus 102, a second pairing of the third bus 103 and the fourth bus 104, and a third pairing of the fifth bus 105 and the sixth bus 106), and none of the controllers 120, 122, 124, 126, 128, 130 is connected to both buses in the respective bus pair. For example, the first controller 120 can be connected to the first bus 101 and the third bus 103, while the second controller 122 is connected to the buses 101 and 105, the third controller 124 is connected to the buses 103 and 105, the fourth controller 126 is connected to the buses 102 and 104, the fifth controller 128 is connected to the buses 102 and 106, and the sixth controller 130 is connected to the buses 104 and 106.

[0013] In an exemplary embodiment, each of the controllers is coupled to at least two of the flight control modules 110, 112, 114 such that a respective controller 120, 122, 124, 126, 128, 130 is coupled to each of the flight control modules 110, 112, 114 without triple bus connections or interfaces in the controllers 120, 122, 124, 126, 128, 130. Also, in an exemplary embodiment having six buses 101, 102, 103, 104, 105, 106 in a dual triple arrangement, each of the controllers 120, 122, 124, 126, 128, 130 is isolated from four of the buses 101, 102, 103, 104, 105, 106 due to the lack of physical electrical connections to the respective isolated buses.

[0014] The flight control modules 110, 112, 114 generally represent processing systems, processing devices, hardware, circuits, logic, software, firmware and / or other components that are configured to receive signals indicating a sensed or measured position, orientation, or adjustment to a user interface device in an aircraft cockpit, and convert the input or adjustment received at the user interface device into a corresponding command signal for one or more flight control components, and output or otherwise provide the command signal to the one or more flight control components via a subset of buses 101, 102, 103, 104, 105, 106 to which the respective flight control modules 110, 112, 114 are coupled. For purposes of explanation, the flight control modules 110, 112, 114 may alternatively be referred to herein as flight control computers (FCCs). Each flight control computer 110, 112, 114 may be implemented or realized using any suitable processing system and / or device, such as, for example, one or more processors, central processing units (CPUs), controllers, microprocessors, microcontrollers, processing cores and / or other hardware computing resources configured to support the operations described herein. In this regard, each flight control computer 110 , 112 , 114 may include or have access to a data storage element (or memory) capable of storing programming instructions for execution that, when read and executed by the flight control computer 110 , 112 , 114 , causes the flight control computer 110 , 112 , 114 to support operation of the fly-by-wire system 100 .

[0015] The cockpit user interface device onboard the aircraft may be implemented as a keypad, touchpad, keyboard, mouse, touch panel (or touch screen), joystick, control rod, switch, knob, line selection key, or other suitable device suitable for receiving input from a user. For example, the cockpit user interface device may be implemented as a joystick, which includes a corresponding group of redundant sensors configured to sense the position of the corresponding joystick in a first reference direction (e.g., horizontal or x reference direction), and an additional group of sensors configured to sense the position of the corresponding joystick in a second reference direction (e.g., vertical or y reference direction), each sensor in each group is coupled to one of the flight control computers. It should be noted that while the subject matter may be primarily described herein in the context of sensor data associated with pilot input or other input received via a user interface device for operating flight control components in a fly-by-wire aircraft, the subject matter described herein is not intended to be limited to sensor data or any particular type of sensing device, and may be used in the context of other sensors (e.g., inertial reference sensors) or any other type of measurement or command data (e.g., flight plan data) that may be input to a flight control module for the purpose of determining flight control component commands. Thus, the present subject matter may be implemented in an equivalent manner for autonomous or remotely controlled aircraft.One or more exemplary arrangements of cockpit user interface devices, sensors, and flight control computers are described and depicted in U.S. Patent Application Serial No. 16 / 048,612, which is incorporated herein by reference.

[0016] One or more avionics systems are also communicatively coupled to each of the flight control computers 110, 112, 114 via a data bus. The avionics systems support navigation, flight planning, and other aircraft control functions in a conventional manner and provide real-time data and / or information about aircraft operations to the flight control computers 110, 112, 114 for analysis in conjunction with sensed user interface device data received from sensors. A practical implementation will likely include one or more of the following avionics systems appropriately configured to support aircraft operations: a flight management system (FMS), a navigation system, a communication system, an autopilot system, an autothrust system, a weather system, an air traffic management system, a radar system, a traffic avoidance system, a hydraulic system, a pneumatic system, an environmental system, an electrical system, an engine system, a trim system, a lighting system, a crew alert system, an electronic checklist system, an electronic flight bag, and / or another suitable avionics system. One or more exemplary arrangements of avionics systems and flight control computers are described and depicted in U.S. Patent Application Serial No. 16 / 048,612, which is incorporated herein by reference.

[0017] Based on data or information received from the corresponding avionics system and the sensed position or adjustment of the corresponding user interface device, each of the flight control computers 110, 112, 114 redundantly determines commands for controlling the position of one or more flight control components or otherwise operating one or more flight control components to adjust the position and / or attitude of the aircraft. The controllers 120, 122, 124, 126, 128, 130 generally represent processing systems, processing devices, hardware, circuits, logic, software, firmware and / or other components of the corresponding systems 120, 122, 124, 126, 128, 130, which are capable of receiving commands for the corresponding flight control components and generating corresponding commands to operate motors or other actuators associated therewith to adjust or otherwise control the corresponding flight control components to track the commands provided by one or more of the flight control computers 110, 112, 114. In this regard, the controller may be implemented or realized using any suitable processing system and / or device, such as, for example, one or more processors, central processing units (CPUs), controllers, microprocessors, microcontrollers, processing cores and / or other hardware computing resources configured to support the operations described herein.

[0018] In an exemplary embodiment, each of the buses 101, 102, 103, 104, 105, 106 is implemented as a controller area network (CAN) bus, wherein each of the flight control computers 110, 112, 114 and the controllers 120, 122, 124, 126, 128, 130 includes a CAN transceiver (or similar communication interface) (or is coupled to the corresponding CAN bus 101, 102, 103, 104, 105, 106 via a corresponding CAN transceiver). For example, the first controller 120 may include or be coupled to a first CAN transceiver 140 coupled to the first CAN bus 101 and a second CAN transceiver 142 coupled to the third CAN bus 103. Similarly, the first flight control computer 110 may include or be coupled to a first CAN transceiver 144 coupled to the first CAN bus 101, a second CAN transceiver 146 coupled to the second CAN bus 102, a third CAN transceiver 148 coupled to the third CAN bus 103, and a fourth CAN transceiver 150 coupled to the fourth CAN bus 104. It should be noted that although the subject matter is primarily described herein in the context of a CAN bus, the subject matter described herein is not limited to a CAN bus and may be implemented in an equivalent manner using other types of communication buses (e.g., Avionics Full Duplex Switched Ethernet (AFDX)), including communication buses or configurations including more than one transmitter and receiver sharing a common physical communication medium.

[0019] During aircraft operation, each of the flight control computers 110, 112, 114 continuously analyzes the outputs of the user interface sensors and the onboard avionics systems to determine, in substantially real time, corresponding commands for how the corresponding flight control components should operate in response to adjustments or changes to the user interface devices. For each corresponding flight control component, each of the flight control computers 110, 112, 114 generates a corresponding command, which is encoded into a CAN message having a header that identifies the appropriate controller 120, 122, 124, 126, 128, 130 and / or flight control component as the intended recipient of the command, and each of the flight control computers 110, 112, 114 outputs, transmits, or otherwise provides the resulting message to a corresponding subset of the CAN buses 101, 102, 103, 104, 105, 106 to which the corresponding flight control computer 110, 112, 114 is connected. Each of the controllers 120, 122, 124, 126, 128, 130 continuously monitors the corresponding CAN bus 101, 102, 103, 104, 105, 106 to which it is connected for messages identifying the flight control component associated therewith as the intended recipient. In response to identifying a message intended for its associated flight control component, the controller 120, 122, 124, 126, 128, 130 decodes, parses, or otherwise analyzes the message to identify a command adjustment for its associated flight control component and generates a corresponding command for operating a motor or other actuator to achieve the desired response from the flight control component. In an exemplary embodiment, a cyclic redundancy check (CRC) or similar encoding scheme may be utilized to prevent communication errors and improve or ensure the integrity of messages received by the controllers 120, 122, 124, 126, 128, 130.

[0020] This article is in Figure 1The subject matter described in the context of providing an independent communication path that achieves relatively high availability by maintaining support for communication between at least one flight control computer and all controllers 120, 122, 124, 126, 128, 130 in the event of an adverse condition or another anomaly or problem relative to two or more other flight control computers. For example, in an embodiment with three flight control computers, after a problem occurs in any one or any two flight control computers, the remaining third flight control computer still has the ability to transmit commands to all controllers 120, 122, 124, 126, 128, 130. In addition, a problem relative to any individual flight control computer or controller does not adversely degrade all CAN buses 101, 102, 103, 104, 105, 106 because no control module is connected to each of the CAN buses 101, 102, 103, 104, 105, 106. In this regard, avoiding fully redundant physical electrical connections between all flight control computers and controllers 120, 122, 124, 126, 128, 130 helps ensure that a potential common cause electrical short or high voltage fault does not propagate across all CAN buses 101, 102, 103, 104, 105, 106 and / or all flight control computers. Relatively high data integrity can also be achieved using CRCs of CAN messages addressed to individual controllers 120, 122, 124, 126, 128, 130 (in addition to electrical or other isolation between CAN buses 101, 102, 103, 104, 105, 106). Available bus bandwidth is also improved for aircraft with a large number of controllers 120, 122, 124, 126, 128, 130 relative to a configuration using fewer CAN buses 101, 102, 103, 104, 105, 106.

[0021] It should be noted that the subject matter described herein also mitigates potential single point failure conditions that may affect multiple CAN buses (e.g., a short between two CAN buses, a controller spamming a CAN bus to which it is connected, etc.) by maintaining increased operational availability in response to the failure condition. In this regard, Figure 2A VTOL aircraft 200 is depicted having twelve flight control components 202 (e.g., lift fans), each of which has a control system 204 (e.g., one or more motor controllers), connected to flight control computers (e.g., flight control computers 110, 112, 114) of the VTOL aircraft 200 via six different CAN buses configured in accordance with the fly-by-wire system 100. For example, a controller for a first lift fan 210 may include a first motor controller 212 connected to a first subset of flight control computers (e.g., flight control computers 110 and 114) via a first CAN bus (e.g., bus 101) labeled A1, and further connected to a different subset of flight control computers (e.g., flight control computers 110 and 112) via a different CAN bus (e.g., bus 103) labeled B1, and so on.

[0022] refer to Figure 2 And continue to refer to Figure 1 Due to the dual-triple wiring configuration of the fly-by-wire system 100, there are twelve different combinations or subgroups of two of the six CAN buses, such that each lift fan control system can be connected to a unique subgroup of the six CAN buses relative to the other lift fan control systems. Therefore, a fault condition relative to any two CAN buses only affects the operation of one of the twelve lift fans 202. For example, if a fault affects both the B1 and C1 CAN buses (e.g., buses 103 and 105), only one lift fan (e.g., lift fan 220 whose motor controller 222 is connected to the B1 CAN bus 103 and the C1 CAN bus 105) may be damaged, while the remaining lift fans 202 will maintain communication with at least one flight control computer via at least one CAN bus. For example, in the event that the B1 CAN bus 103 loses availability, the first motor controller 212 of the first lift fan 210 maintains communication with at least two of the flight control computers via the A1 CAN bus 101. Therefore, Figure 1 The fly-by-wire system 100 is advantageous for VTOL aircraft or other aircraft that are less resilient or less tolerant to the loss of flight control components by limiting the potential loss of the control system to one-twelfth of the total.

[0023] For the sake of brevity, conventional techniques related to fly-by-wire systems, avionics systems, avionics standards, avionics installations, communication buses, communication protocols, encoding and / or decoding, formatting, and other functional aspects of the systems (and the individual operating components of the systems) may not be described in detail herein. In addition, the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and / or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in embodiments of the described subject matter. Therefore, although Figure 1 Direct electrical connections between components may be depicted, but alternative embodiments may employ intervening circuit elements and / or components while functioning in a substantially similar manner.

[0024] The subject matter can be described herein according to functions and / or logic block components and reference to symbolic representations of operations, processing tasks and functions that can be performed by various computing components or devices. It should be understood that the various block components shown in the figure can be implemented by any number of hardware components configured to perform a specified function. For example, the implementation scheme of the system or component can adopt various integrated circuit components, such as memory elements, digital signal processing elements, logic elements, lookup tables, etc., which can perform multiple functions under the control of one or more microprocessors or other control devices. In addition, the implementation scheme of the subject matter described herein can be stored on any suitable non-transient computer-readable medium, encoded thereon or otherwise embodied thereon as computer executable instructions or data stored thereon, which, when executed (e.g., by a processing system), are conducive to the above process.

[0025] The foregoing description refers to the element or node or feature that is "coupled" together. As used herein, unless otherwise clearly indicated, "coupling" refers to an element / node / feature that is directly or indirectly connected (or communicates directly or indirectly) to another element / node / feature, and not necessarily by mechanical means. Therefore, although the accompanying drawings may depict an exemplary arrangement of elements directly coupled to each other, additional intermediate elements, equipment, feature or parts may be present in the embodiment of the depicted theme. In addition, certain terms may also be used in the following description for reference only, and are therefore not intended to be limited. For example, unless the context clearly indicates, the terms "first", "second" and other such numerical terms related to the structure do not imply an order or sequence.

[0026] Although at least one exemplary embodiment has been presented in the aforementioned specific embodiments, it should be understood that there are a large number of variations. It should also be understood that an exemplary embodiment or multiple exemplary embodiments are only examples and are not intended to limit the scope, applicability or configuration of the subject matter in any way. On the contrary, the aforementioned specific embodiments will provide a convenient roadmap for implementing the exemplary embodiments of the subject matter for those skilled in the art. It should be understood that, without departing from the scope of the subject matter as set forth in the attached claims, various changes can be made to the functions and arrangements of the elements described in the exemplary embodiments. Therefore, in the absence of a clear intention to the contrary, the details of the above exemplary embodiments or other restrictions should not be interpreted into the claims.

Claims

1. A vehicle electrical system, comprising: a bus arrangement, the bus arrangement comprising a plurality of buses; a first control module coupled to a first subset of the plurality of buses, the first subset comprising a first bus, a second bus, a third bus, and a fourth bus; a second control module coupled to a second subset of the plurality of buses, the second subset including the third bus, the fourth bus, the fifth bus, and the sixth bus; and a third control module coupled to a third subgroup of the plurality of buses, the third subgroup comprising the first bus, the second bus, the fifth bus, and the sixth bus, a control system coupled to a fourth subset of the plurality of buses; and a second control system coupled to a fifth subset of the plurality of buses, wherein: The first subgroup, the second subgroup, the third subgroup, the fourth subgroup and the fifth subgroup are different from each other; The fourth subgroup includes the first bus and the third bus; and The fifth subgroup includes the second bus and the fourth bus. 2 . The vehicle electrical system of claim 1 , further comprising a first flight control component coupled to the control system and a second flight control component coupled to the second control system.

3. The vehicle electrical system of claim 1 , further comprising a flight control component coupled to the control system, wherein: The plurality of buses include a plurality of controller area network (CAN) buses; and Each of the first control module, the second control module and the third control module is configured to: determining commands for operating the flight control components; generating a CAN message addressed to the flight control component and containing the command; as well as The CAN message is output to a respective one of the first sub-group, the second sub-group, and the third sub-group coupled to a respective one of the first control module, the second control module, and the third control module.

4. The vehicle electrical system of claim 3, wherein the flight control component comprises a lift fan of a vertical take-off and landing (VTOL) aircraft.

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