Patent Publication Number: US-2023139984-A1

Title: Dual-purpose control moment gyroscope for vehicle control

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. Provisional Patent Application No. 63/273,059, filed Oct. 28, 2021, the entire content of which is incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     The present disclosure generally relates to control moment gyroscopes (CMGs), and more particularly relates to CMGs that use the angular momentum of presently existing rotating machinery in a vehicle. 
     BACKGROUND 
     Historically, spacecraft have used CMGs to implement attitude control. Typically, a CMG consists of a large mass/inertia rotor that is spinning at a fixed speed (e.g., 6000 RPM or higher). The spinning rotor may be rotated with a gimbal (geared or direct drive motor), and the angular rate of the gimballed rotor produces a gyroscopic torque and transfers momentum to and from the spacecraft. 
     Over the past several years, the use of CMGs in non-space applications has been investigated and, in some cases, implemented. For example, CMGs have been implemented in seagoing vessels for roll-stabilization, and have been experimentally implemented in small, 2-wheel motor vehicles for roll axis control. While it would be desirable to implement CMGs in aircraft, since doing so would reduce or eliminate aerodynamic control effectors and associated control surfaces, CMG use in aircraft applications have not been pursued. This, in large part, is due to the significant mass that is required to implement a CMG. 
     Hence, there is a need for a way to implement CMGs in at least aircraft applications (as well as other non-space vehicles) that does not result in significant mass increase to the vehicle. The present disclosure addresses at least this need. 
     BRIEF SUMMARY 
     This summary is provided to describe select concepts in a simplified form that are further described in the Detailed Description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
     In one embodiment, a vehicle includes a vehicle body, a vehicle power source, and an actuator. The vehicle power source includes a housing and a power generator. The housing is rotationally mounted on the vehicle body and is configured to rotate, relative to the vehicle body, about a first rotational axis. The power generator is rotationally mounted within the housing and is configured to rotate about a second rotational axis and generate power. The first rotational axis and the second rotational axis are orthogonally disposed. The actuator is coupled to the housing and is operable to selectively rotate the housing about the first rotational axis. 
     In another embodiment, a vehicle includes a vehicle body, a vehicle power source, a first flexible duct, a second flexible duct, and an actuator. The vehicle power source includes a housing and a power generator. The housing includes an inlet and an outlet and is rotationally mounted on the vehicle body and is configured to rotate, relative to the vehicle body, about a first rotational axis. The power generator is rotationally mounted within the housing and is configured to rotate about a second rotational axis and generate power. The first rotational axis and the second rotational axis are orthogonally disposed. The first flexible duct is coupled to the inlet, and the second flexible duct is coupled to the outlet. The actuator is coupled to the housing and is further coupled to receive actuator commands. The actuator is configured, in response to the actuator commands, to rotate the housing about the first rotational axis. 
     Furthermore, other desirable features and characteristics of the vehicle will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the preceding background. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein: 
         FIG.  1    is a functional block diagram of one embodiment of a vehicle with a dual-purpose control moment gyroscope (CMG); 
         FIG.  2    depicts one embodiment of an auxiliary power unit that may be used to implement the dual-purpose CMG of  FIG.  1   ; and 
         FIG.  3    depicts one embodiment of a gas turbine propulsion engine that may be used to implement the dual-purpose CMG of  FIG.  1   . 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Thus, any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments. All of the embodiments described herein are exemplary embodiments provided to enable persons skilled in the art to make or use the invention and not to limit the scope of the invention which is defined by the claims. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary, or the following detailed description. 
     A CMG typically requires massive, large inertia rotors run at a relatively high speed to provide the desired angular momentum, that is subsequently gimbaled to produce a large gyroscopic torque and transfer momentum to and from the host vehicle. The rotors are typically the largest (and most massive) portion of the CMG. Given that rotating machines are (or can be) already included in aircraft powerplants (e.g., megawatt generator or jet engine), utilizing these rotating machines that are already present for the angular momentum of the CMG, eliminates the need for a dedicated (and heavy) CMG rotor. 
     The addition of a gimbal system to apply a desired angular rate to the turbomachine, along with flexible ducting on the inlet and outlet such that these do not change locations. CMGs in this application may be limited angle devices utilized to apply torques and transfer momentum to one or more axes. The simplest solution utilizes a scissored-pair (e.g., two generators or jet engines), where the rotating inertia of these devices serves as the CMG rotating inertia. Torque (T) is generated as T=‘w’×‘h’ (where, ‘w’=gimbal rate, ‘h’=rotor momentum, x=vector cross product), per a standard CMG. The momentum of the pair is controlled via the momentum vectors of the two devices (e.g., the rotation axes). 
     Referring to  FIG.  1   , a functional block diagram of one embodiment of a vehicle  100  with a dual-purpose CMG is depicted and includes a vehicle body  102 , a vehicle power source  104 , and an actuator  106 . The vehicle  100  may be any one of numerous vehicles that are non-spacecraft vehicles. For example, the vehicle  100  may be any one of numerous types of aircraft, any one of numerous types of terrestrial vehicles, or any one of numerous types of seagoing vessels or vehicles. 
     The vehicle power source  104  is disposed on or within the vehicle body and may be any one of numerous types of power sources. For example, it may be a gas turbine propulsion engine, an auxiliary power unit (APU), a generator, or any one of numerous other types power sources with a rotating mass. For completeness, two examples of potential vehicle power sources  104  are depicted in  FIGS.  2  and  3   . In particular,  FIG.  2    depicts an APU and  FIG.  3    depicts a gas turbine propulsion engine. 
     Returning to  FIG.  1   , regardless of how the vehicle power source  104  is specifically implemented, it includes a housing  108  and a power generator  112 . The housing  108  is rotationally mounted on the vehicle body  102  via, for example, a set of bearings  114 . The housing  108  is thus configured to rotate, relative to the vehicle body  102 , about a first rotational axis  118 . The power generator  112 , which may be a Propulsion turbine engine, an internal combustion engine, an electrical generator whose primary mover could be a turbine or internal combustion engine, just to name a few, is rotationally mounted within the housing  108  and is configured to rotate about a second rotational axis  116  and generate power. As  FIG.  1    depicts, the first rotational axis  118  and the second rotational axis  116  are orthogonally disposed. 
     The actuator  106  is coupled to the housing  108  and is operable to selectively rotate the housing  108  about the first rotational axis  118 . As such, and as noted above, the rotating inertia of the vehicle power source  104 , in which the power generator  112  is rotating about the second rotational axis  116 , serves as the CMG rotating inertia. In the depicted embodiment, the actuator  106  is responsive to actuator commands it receives to rotate the housing  108  about the first rotational axis  118 . 
     The actuator commands received by the actuator  106  are, at least in the depicted embodiment, supplied from a controller  122 . The controller  122  is in operable communication with the actuator  106  configured to generate and supply the actuator commands More specifically, the controller  122  is coupled to receive input commands and is configured, in response to the input commands, to generate and supply the actuator commands. 
     As  FIG.  1    further depicts, the controller  122  is coupled to receive the input commands from, for example, an interface  124 . The interface  124  may vary depending, for example, on the type of vehicle  100 . The user interface  124  can be one of many analog or digital electrical interfaces providing commands to the controller  122 , as well as the desired feedback signals (sensors  128 , internally calculated in controller  122 , etc.) back to the source of the interface. It is most likely that the interface  124  is comprised of 2-way signals from the host vehicle&#39;s automatic control system. The controller  122 , as already noted, is configured, in response to the input commands supplied from the interface  124 , to generate and supply the actuator commands to the actuator  106 . 
     The controller  122  is also coupled to receive input from one or more sensors  128 . Although the number and types of sensors  128  may vary, the depicted embodiment includes three types of sensors  128 , which include one or more attitude sensors  128 - 1  one or more rate sensors  128 - 2 , and one or more rotational speed sensors  128 - 3 . The one or more attitude sensors  128 - 1  are configured sense vehicle attitude. The one or more rate sensors  128 - 2  are configured to sense the rotational rate of the vehicle power sources  104  relative to the vehicle body  102 . The one or more rotational speed sensors  128 - 3  are configured to sense the rotational speed of the power generator  112  relative to housing  108 . The sensors  128  supply sensor signals, to the controller  122 , that are representative of the parameters that each sensor senses. The controller  122  is configured, in response to the sensor signals, to control the gyroscopic torque supplied to the vehicle body  102  as commanded via interface  124 , so that the gyroscopic torque is stable and within allowable limits. 
     Because the vehicle power source  104  is mounted to rotate relative to the vehicle body  102 , the vehicle  100  may also be equipped with flexible ducting  132  on the inlet and outlet or input and output, depending on how the vehicle power source  104  is implemented. The flexible ducting  132  permits the angular rotation of the vehicle power source  104  over the required angular range of motion, which may be, for example, ±5-175 degrees. 
     Although the vehicle  100  in  FIG.  1    is depicted with only one vehicle power source  104  and one associated actuator  106 , it will be appreciated that the vehicle  100  could be implemented with two or more vehicle power sources  104  and associated actuators  106 . Moreover, in some embodiments, a single actuator  106  could be used to rotate more than one vehicle power source  104 . It is additionally noted that, although not depicted, power and signal transfer across the rotating interface between the vehicle body  102  and vehicle power source  104  is provided using any one of numerous known techniques such as, for example, flexible cable, or slip ring assemblies, as is known in the art. 
     Those of skill in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. Some of the embodiments and implementations are described above in terms of functional and/or logical block components (or modules) and various processing steps. However, it should be appreciated that such block components (or modules) may be realized by any number of hardware, software, and/or firmware components configured to perform the specified functions. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention. For example, an embodiment of a system or a component may employ various integrated circuit components, e.g., memory elements, digital signal processing elements, logic elements, look-up tables, or the like, which may carry out a variety of functions under the control of one or more microprocessors or other control devices. In addition, those skilled in the art will appreciate that embodiments described herein are merely exemplary implementations. 
     The various illustrative logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. 
     When implemented in software or firmware, various elements of the systems described herein are essentially the code segments or instructions that perform the various tasks. The program or code segments can be stored in a processor-readable medium or transmitted by a computer data signal embodied in a carrier wave over a transmission medium or communication path. The “computer-readable medium”, “processor-readable medium”, or “machine-readable medium” may include any medium that can store or transfer information. Examples of the processor-readable medium include an electronic circuit, a semiconductor memory device, a ROM, a flash memory, an erasable ROM (EROM), a floppy diskette, a CD-ROM, an optical disk, a hard disk, a fiber optic medium, a radio frequency (RF) link, or the like. The computer data signal may include any signal that can propagate over a transmission medium such as electronic network channels, optical fibers, air, electromagnetic paths, or RF links. The code segments may be downloaded via computer networks such as the Internet, an intranet, a LAN, or the like. 
     In this document, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Numerical ordinals such as “first,” “second,” “third,” etc. simply denote different singles of a plurality and do not imply any order or sequence unless specifically defined by the claim language. The sequence of the text in any of the claims does not imply that process steps must be performed in a temporal or logical order according to such sequence unless it is specifically defined by the language of the claim. The process steps may be interchanged in any order without departing from the scope of the invention as long as such an interchange does not contradict the claim language and is not logically nonsensical. 
     Furthermore, depending on the context, words such as “connect” or “coupled to” used in describing a relationship between different elements do not imply that a direct physical connection must be made between these elements. For example, two elements may be connected to each other physically, electronically, logically, or in any other manner, through one or more additional elements. 
     As used herein, the term “axial” refers to a direction that is generally parallel to or coincident with an axis of rotation, axis of symmetry, or centerline of a component or components. For example, in a cylinder or disc with a centerline and generally circular ends or opposing faces, the “axial” direction may refer to the direction that generally extends in parallel to the centerline between the opposite ends or faces. In certain instances, the term “axial” may be utilized with respect to components that are not cylindrical (or otherwise radially symmetric). For example, the “axial” direction for a rectangular housing containing a rotating shaft may be viewed as a direction that is generally parallel to or coincident with the rotational axis of the shaft. Furthermore, the term “radially” as used herein may refer to a direction or a relationship of components with respect to a line extending outward from a shared centerline, axis, or similar reference, for example in a plane of a cylinder or disc that is perpendicular to the centerline or axis. In certain instances, components may be viewed as “radially” aligned even though one or both of the components may not be cylindrical (or otherwise radially symmetric). Furthermore, the terms “axial” and “radial” (and any derivatives) may encompass directional relationships that are other than precisely aligned with (e.g., oblique to) the true axial and radial dimensions, provided the relationship is predominantly in the respective nominal axial or radial direction. As used herein, the term “substantially” denotes within 5% to account for manufacturing tolerances. Also, as used herein, the term “about” denotes within 5% to account for manufacturing tolerances. 
     While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention. It being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims.