Aerial vehicle comprising a compliant arm

Abstract

An aerial vehicle including a compliant arm. A method for controlling an aerial vehicle including a compliant arm mechanism is disclosed. A propulsion system of the aerial vehicle is controlled (1302) to cause the aerial vehicle to fly in a region proximate to a surface. One or more of the propulsion system and the compliant arm mechanism are controlled (1304) to cause the compliant arm mechanism to contact the surface. The compliant arm mechanism is configured to extend laterally beyond a perimeter of the propulsion system. One or more sensor signals indicative of the compliant arm mechanism contacting the surface are received (1306) by a sensor. A force at which the aerial vehicle is pressing against the surface is determined (1308) based on the one or more sensor signals.

Description

Background Technology

[0001] This disclosure generally relates to the field of aircraft, and more specifically to aircraft including compliant arm mechanisms.

[0002] Robotic arms can be used in various applications, such as picking up and placing objects. Some robotic arms include an actuation system comprising a motor connected to a high gear ratio drive. This actuation system has a high torque density, which allows the robotic arm to effectively lift and move objects. However, such an actuation system has high inherent friction and inertia that reduce the robotic arm's responsiveness to mechanical contact. For example, when the end point of such a robotic arm contacts a hard surface, the contact force (i.e., the force transmitted due to contact) is almost instantaneous, and the actuation system does not allow the robotic arm to have significant compliance with the surface. Summary of the Invention

[0003] According to one aspect of this disclosure, an example method for controlling an aircraft including a compliant arm is disclosed. The propulsion system of the aircraft is controlled to cause the aircraft to fly in a region adjacent to a surface. One or more of the propulsion system and the compliant arm mechanism are controlled such that the compliant arm mechanism contacts the surface. The compliant arm mechanism is configured to extend laterally beyond the periphery of the propulsion system. One or more sensor signals are received via sensors indicating the contact between the compliant arm mechanism and the surface, and the force exerted by the aircraft on the plane is determined based on the one or more sensor signals.

[0004] The features, functions, and advantages discussed can be implemented independently in multiple instances or combined in other instances, and further details can be found in the following description and figures. Attached Figure Description

[0005] Figure 1 This is a schematic diagram of an exemplary example of an aircraft vehicle that includes a compliant arm mechanism.

[0006] Figure 2 This is a schematic diagram of an exemplary example of an active compliant arm mechanism.

[0007] Figure 3 This is a schematic diagram of an exemplary example of a passive compliant arm mechanism.

[0008] Figure 4 This is a schematic diagram of an exemplary example of a compliant arm mechanism that includes three degrees of freedom of motion.

[0009] Figure 5 This is a schematic diagram of an exemplary example of a compliant arm mechanism configured to hold an object in place by an adhesive.

[0010] Figure 6This is a schematic diagram of an exemplary example of a compliant arm mechanism configured to hold an object by vacuum.

[0011] Figure 7 This is a schematic diagram of an exemplary example of a compliant arm mechanism configured to hold an object by means of a magnet.

[0012] Figure 8 This is a schematic diagram of an exemplary instance of a compliant arm mechanism configured to hold an object using a friction-based clamp.

[0013] Figure 9 This is a schematic diagram of an exemplary instance of a compliant arm mechanism configured to hold an object by actuating fingers.

[0014] Figures 10A-10F This is a schematic diagram of an example scenario where an aircraft places an object on a vertical surface using a compliant arm mechanism.

[0015] Figure 11A-11E This is a schematic diagram of an example scenario where an aircraft places an object on an inclined surface using a compliant arm mechanism.

[0016] Figures 12A-12C This is a schematic diagram of an example scenario where an aircraft places an object on a vertical surface using a passive compliant arm mechanism.

[0017] Figure 13 This is a flowchart of an exemplary example of a method for controlling an aircraft including a compliant arm mechanism. Detailed Implementation

[0018] When the end point of a robotic arm driven by an actuation system comprising one or more motors connected to a high gear ratio (e.g., 50:1 or greater) contacts a hard surface, the high inherent friction and inertia of the actuation system do not allow for meaningful active control of the motors(s) to control the mechanical resistance of the robotic arm relative to the hard surface. In scenarios where such a robotic arm is connected to an aircraft such that the forces generated by the robotic arm can severely interfere with the aircraft's flight dynamics, the non-compliance of the robotic arm transmits the contact forces through the robotic arm to the aircraft. Similarly, the aircraft's flight dynamics can interfere with the robotic arm's positioning.

[0019] Therefore, examples relating to compliant arm mechanisms for aircraft, aircraft including compliant arm mechanisms, and methods for controlling such aircraft are disclosed. As described in more detail below, the compliant arm mechanism according to this disclosure controls the mechanical impedance of the endpoints of the aircraft by reducing the contact forces generated due to contact with a surface and decoupling such contact forces from the flight forces of the aircraft. Furthermore, when the compliant arm mechanism contacts a surface to control the mechanical impedance, this compliant arm mechanism can be used to provide force sensing capability. In some instances, this force sensing capability is used to characterize the spatial relationship between the aircraft and a plane, which enables control of the orientation of the aircraft relative to the surface. In other instances, the geometry of the compliant arm mechanism defines the relative position of the aircraft and the surface when the endpoints of the compliant arm mechanism contact the surface. Further, in some instances, this force sensing capability is used to assist in placing an object on said surface. Such a surface can be a substantially vertical surface, such as a wall, or tilted at any suitable angle (inclined or declined). Furthermore, in some instances, the compliant arm mechanism is controlled to contact a surface in order to stabilize the position of the aircraft. For example, if the aircraft experiences a strong wind, the compliant arm mechanism is controlled to contact the surface and / or apply force to the surface to stabilize the aircraft.

[0020] Figure 1 This is a schematic diagram of an exemplary example of an aircraft vehicle 100 including a compliant arm mechanism 102. The aircraft vehicle 100 includes a frame 104 (e.g., a fuselage or other structure), a plurality of cantilever arms 106A-F extending radially from the frame 104, and corresponding plurality of landing gears 108A-F such that each cantilever provides one landing gear. In some instances, the frame 104 and the plurality of cantilever arms 106A-F may be manufactured as a single unit. In other instances, the frame 104 and the plurality of cantilever arms 106A-F may be manufactured as independent components connected to each other. In various instances, the components of the aircraft vehicle 100 may be manufactured from metals, composite materials, polymeric materials, ceramic materials, and / or combinations thereof.

[0021] The propulsion system 109 is connected to the frame 104. In the example shown, the propulsion system 109 includes a plurality of rotor thrusters 110A-F. Each rotor thruster 100 is connected to the distal end of a corresponding cantilever 106. Each rotor thruster is configured to rotate to direct upward or downward thrust relative to the frame 104 and may include any suitable type of motor to rotate the rotor thruster. The rotor thrusters 110A-F may be selected to rotate clockwise / counterclockwise such that the net yaw moment on the aircraft 100 is zero during normal hovering and forward flight. Although the propulsion system 109 is shown as having six rotor thrusters, it should be understood that the propulsion system 109 may include more or fewer rotor thrusters to achieve a desired function, such as fulfilling a specific thrust requirement. In the example shown, the aircraft may take any other suitable form. The propulsion system 109 is controlled by an aircraft control system (also referred to herein as a controller) 112 to enable flight of the aircraft 100.

[0022] The aircraft is equipped with a compliant arm mechanism 102 to control the mechanical impedance of the end point of the aircraft 100 to form contact forces and to provide force sensing capability when the end point of the aircraft 100 contacts a surface. The compliant arm mechanism 102 is configured to control the mechanical impedance by controlling the compliance (force in response to position) and damping (force in response to velocity) of the compliant arm mechanism 102. In some instances, the compliant arm mechanism 102 is configured to control other force / dynamic relationships. Further, in some instances, this force sensing capability is used to characterize the spatial relationship between the aircraft 100 and the surface, allowing control of the aircraft's orientation relative to the surface. In some instances, this force sensing capability is used to control the flight stability of the aircraft 100. Further, in some instances, the compliant arm mechanism 102 is configured to releasably hold an object, and this force sensing capability is used to assist in placing an object on a surface.

[0023] The compliant arm mechanism 102 is attached to the underside of the frame 104 so that it does not interfere with the operation of the propulsion system 109. The compliant arm mechanism 102 provides a compact configuration during flight of the aircraft 100 to simplify flight dynamics (e.g., the center of gravity of the compliant arm mechanism 102 is located near the center of gravity of the aircraft 100 during flight). Furthermore, the compliant arm mechanism 102 is sized and positioned to allow multiple landing gears 108 to land during landing of the aircraft 100.

[0024] In some instances, the compliant arm mechanism 102 is integrated with the aircraft vehicle 100. In other instances, the compliant arm mechanism 102 is configured as a system to be removably attached to the aircraft vehicle 100 or any other aircraft capable of carrying the compliant arm mechanism 102.

[0025] The compliant arm mechanism 102 provides one or more degrees of freedom of motion to extend laterally from the aircraft 100 beyond the periphery of the propulsion system 109 to interact with the surface, while preventing the propulsion system 109 from contacting the surface.

[0026] The compliant arm mechanism 102 includes a compliant column 114 connected to a hand 116. The compliant column includes a first column portion 115 and a second column portion 117 connected together by an extendable connector 118. The extendable connector 118 is configured to move the compliant column 114 between a retracted position and an extended position. In the retracted position, the second column portion 117 retracts within the first column portion 115. In the extended position, the second column portion 117 moves outward and extends laterally beyond the periphery of the propulsion system 109. For example, the compliant column 114 can be retracted via the extendable connector 118 during dynamic flight of the aircraft 100, and can be extended via the extendable connector 118 when the aircraft 100 hovers near a surface (e.g., a wall). The extendable connector 118 can take any form. For example, the extendable connector may include a prismatic connector or a telescopic connector.

[0027] The compliant arm mechanism 102 includes an elbow connector 120 formed between a compliant column and a hand 116. The elbow connector 120 provides at least one degree of freedom of movement for the compliant hand 116 relative to the compliant column. This at least one degree of freedom of movement of the elbow connector 120 allows the compliant hand 116 to be oriented substantially planar relative to the surface during contact, even if the compliant column 114 is not perpendicular to the surface. In the illustrated example, the elbow connector 120 provides a degree of freedom for the compliant hand 116 such that it can rotate to press against an inclined surface or compensate for a non-perpendicular compliant arm 114. In other examples, the elbow connector 120 provides two or more degrees of freedom of movement. In any case, in some examples, the compliance provided by the elbow connector 120 assists the aircraft 100 in placing objects on a surface. Additionally, the extendable connector 118 and the toggle connector 120 cooperate to reduce the impact of contact forces on the flight dynamics of the aircraft 100 when the compliant arm mechanism 102 contacts the surface.

[0028] In some instances, compliant arm mechanisms include one or more motor-driven actuators to provide active impedance control (e.g., compliance and / or damping). Figure 2 This is a schematic diagram of an exemplary example of an active compliant arm mechanism 200. For example, the active compliant arm mechanism 200 corresponds to... Figure 1The compliant arm mechanism 102 is shown. The active compliant arm mechanism 200 includes a compliant column 202 connected to a hand 204. The compliant column 202 includes an extendable connector 206 configured to actively extend and retract the compliant column 202 via a motor 208. In some examples shown, the motor 208 drives a screw 210 engaging with a nut 211 connected to the compliant connector 206 to extend and retract the compliant column 202. In other examples, the extendable connector is driven by other types of active drive mechanisms, such as a motor-driven rack and pinion or a motor-driven belt.

[0029] Hand 204 is connected to the compliant column 202 elbow connector via an elbow connector 212 configured to actively rotate hand 204 by motor 214. Motor 214 is configured to drive drive belt 216 connected to hand 204. For example, motor 214 rotates drive belt 216 counterclockwise to rotate hand 204 upward and rotates drive belt 216 clockwise to rotate hand 204 downward.

[0030] The active drive mechanism (e.g., a drive screw 210 driven by motor 208 and / or a drive belt 216 driven by motor 214) is configured to have a degree of compliance or built-in damping, such that when the active compliant arm mechanism 200 contacts a surface, the contact force is transmitted through and absorbed by the drive mechanism. Furthermore, this contact force is determined based on a force from one or more sensor signals received by one or more sensors on the aircraft, and one or more motors 208 and 214 are controlled based on these sensor signals to adjust the active compliant arm mechanism 200 to counteract the determined force. In this way, when the active compliant arm mechanism 200 contacts a surface, it mitigates the impact of the contact force on the aircraft's flight dynamics.

[0031] The drive screw 210 and drive belt 216 are examples of active compliant components driven by one or more motors, which control the primary mechanical resistance properties of the compliant arm mechanism. In other examples, the active compliant arm mechanism 200 may include components driven by any suitable type of active compliant motor. In the illustrated example, the active compliant arm mechanism 200 includes movement in two degrees of freedom, but in other examples, the compliant arm mechanism may have three or more degrees of freedom.

[0032] In some instances, compliant arm mechanisms include one or more passive components to provide passive compliance through physical deformation of the passive components. Figure 3 This is a schematic diagram of an exemplary example of a passive compliant arm mechanism 300, which is suitable for use as... Figure 1The compliant arm mechanism 102 is shown in the figure. The passive compliant arm mechanism 300 includes a compliant column 302 connected to a hand 304. The compliant column 302 includes a compressible connector 306 configured to passively compress the compliant column 302 in response to a contact force applied to the passive compliant arm mechanism 300. In this example, the compressible connector 306 includes a coil spring 308 configured to laterally outwardly bias the compliant column 302 and compress in response to a contact force greater than the elastic force of the coil spring 308. In some examples, a damper is also used as a compliant component in addition to the coil spring 308 in the compliant arm mechanism 300, or a damper is used in place of the coil spring 308 in the compliant arm mechanism 300.

[0033] Hand 304 is connected to toggle connector 310, which is configured to passively rotate hand 304 in response to a contact force applied to hand 304. Specifically, toggle connector 310 includes a pair of opposing torsion springs 312 that cooperatively bias hand 304 in a central position when passive compliant arm mechanism 300 is not in contact with a surface. Further, the pair of opposing torsion springs 312 allows hand 304 to rotate in a specific direction in response to a contact force not perpendicular to the surface of hand 304 exceeding the spring force of the torsion springs. As an example, hand 304 rotates upward in response to contact with a surface that is not parallel to the contact surface of hand 304 and is inclined outward toward the passive compliant arm mechanism 300. As another example, hand 304 rotates downward in response to contact with a surface that is not parallel to the contact surface of hand 304 and is inclined away from the passive compliant arm mechanism 300.

[0034] In some instances, including fully passive compliant arm mechanisms, the compliant arm mechanism is configured to extend laterally beyond the periphery of the propulsion system in a permanent manner, in contrast to extension and retraction.

[0035] The helical spring 308 and the pair of torsion springs 312 are examples of passive compliant components, and the passive compliant arm mechanism 300 may include any suitable type of passive compliant component. For example, the passive compliant arm mechanism may include one or more other types of springs and / or one or more dampers. In the example shown, the passive compliant arm mechanism 300 provides two degrees of freedom of motion. The impedance control characteristics (e.g., elasticity, damping force) of the passive compliant component can be selected such that when the compliant arm mechanism contacts a surface, the contact force of the compliant arm mechanism is not excessive and interferes with the position of the aircraft.

[0036] In some instances, compliant arm mechanisms include both active and passive compliant components. For example, a compliant column may include both a helical spring that passively absorbs contact forces and a motor that actively extends and retracts the compliant column.

[0037] Figure 4 It is suitable for providing three degrees of freedom of motion. Figure 1 This is a schematic diagram of an exemplary example of a compliant arm mechanism 400, specifically a compliant arm mechanism 102. The compliant arm mechanism 400 includes a compliant column 402 connected to a toggle connector 404. The toggle connector 404 is connected to a hand 406. The compliant column 402 includes an extendable connector 408 configured to actively extend and retract the compliant column 402 via a motor 410. The compliant column 402 can be driven by the motor 410 via any suitable drive mechanism. The toggle connector 404 is configured to actively rotate the hand 406 to any suitable radial position within 360 degrees via a motor 412, and can be actively rotated via any suitable drive mechanism. Further, the hand 406 is configured to actively rotate upwards and downwards via a motor 414. The motor 414 can actively rotate the hand 406 via any suitable mechanism. Furthermore, motors 410, 412, and 414 are controlled collaboratively in three degrees of freedom to orient the hand 406 in any suitable position to interact with the surface.

[0038] Go to Figure 1 The compliant arm mechanism 102 includes one or more sensors 122 configured to output one or more sensor signals indicative of the force applied by the compliant arm mechanism to the surface when the compliant arm mechanism 102 contacts and / or presses against the surface. The one or more sensors 122 can take any suitable form. For example, the one or more sensors may include one or more of a linear potentiometer, a decoder, a strain gauge, and a Hall effect sensor. As an example, one or more sensors sense the operation of a motor configured to actuate an extendable connector 118. The compliant arm mechanism 102 may additionally or optionally include additional sensors located on other connectors of the compliant arm mechanism. Such additional sensors may include position sensors—configured to measure the position of components of the compliant arm mechanism 102 (e.g., elbow connector, hand, fingers)—and / or force sensors—configured to measure the force applied to these components of the compliant arm mechanism 102. In some instances, signals from both the force sensor and the position sensor can be used to collaboratively control the mechanical impedance of the compliant arm mechanism.

[0039] In some instances, the compliant arm mechanism is configured to releasably hold an object, allowing the aircraft to place the object on a surface. In one instance, the aircraft is used to place a surveillance camera on a vertical surface, such as the wall of a building that is difficult for people to access. The compliant arm mechanism can be configured to releasably hold any suitable type of object for placing it on a surface. Figure 5-9 It is suitable for use as Figure 1A schematic diagram of a compliant arm mechanism, having different configurations for releasably holding an object.

[0040] exist Figure 5 In one example, the compliant arm mechanism 500 includes a hand 502 configured to hold an object 504 by an adhesive 506. The adhesive 506 has adhesive properties that allow the object to be released from the hand 502. In some examples, the object 504 is configured with a mechanical attachment mechanism and / or other adhesives to allow the object to attach to and be released from the adhesive 506. Any suitable adhesive can be used to releasably hold the object 504 to the hand 502.

[0041] exist Figure 6 In one example, the compliant arm mechanism 600 includes a hand 602 configured to hold an object 604 via a vacuum 606. In another example, the compliant arm mechanism 600 includes a pump that forms a vacuum 606 between the hand 602 and the object 604. In other examples, the vacuum 606 is maintained passively, for example by a suction cup applied to the hand 602 and / or the object 604 or by an external vacuum generator (e.g., evacuation before flight).

[0042] exist Figure 7 In some examples, the compliant arm mechanism 700 includes a hand 702 configured to hold an object 704 by a magnet 706, wherein the object comprises a material attracted by magnetic force. In some examples, the magnet 706 is a ferromagnet, such as a rare-earth magnet. In other examples, the magnet 706 is an electromagnet. Further, in some examples, the object 704 comprises a ferromagnet or an electromagnet and the hand 702 comprises a material attracted by magnetic force. Further, in some examples, the object 704 is configured to be attached to a surface by magnetic attraction of the surface.

[0043] exist Figure 8 In one example, the compliant arm mechanism 800 includes a hand 802 comprising a plurality of fingers 804. The plurality of fingers 804 are configured to hold an object 806 by a friction-based gripper. Specifically, the size and shape of the plurality of fingers 804 are set to match the shape of the object 806 such that the plurality of fingers 804 can releasably hold the object 806. In the depicted example, the plurality of fingers 804 have fixed positions to create a friction-based grip on the object 806. In some examples, the object 806 includes adhesive or mechanical fastening mechanisms for attaching the object 806 securely enough to overcome the friction-based gripping of the hand 804.

[0044] exist Figure 9In one example, the compliant arm mechanism 900 includes a hand comprising a plurality of actuated fingers 904 configured to hold an object 906, the plurality of actuated fingers 904 being actively driven by a motor 908. In some examples, multiple motors are used such that each of the fingers 904 can be individually actuated to open or close around the object 906. Further, in some examples, each actuated finger 904 is hinged to form different grips around objects of different shapes.

[0045] The examples provided above are examples, and the compliant arm mechanism can be configured to releasably hold an object in any suitable manner. In any of these examples, the compliant arm mechanism provides a compact configuration during normal flight to simplify flight dynamics and offers sufficient degrees of freedom of motion to extend and compliantly place the object on a surface. The compliant arm mechanism has inherent compliant control that provides favorable dynamics to both the aircraft and the compliant arm mechanism when the object is placed on the surface.

[0046] In some instances, the compliant arm mechanism is configured to releasably hold multiple objects for placement in different locations. As an example, the compliant arm mechanism includes a reservoir configured to hold multiple objects. The reservoir is configured such that when one object is placed, the next object in the reservoir moves to the position to be placed. Further, in some instances, the aircraft includes multiple compliant arm mechanisms. In some such instances, each of the multiple compliant arm mechanisms is configured to releasably hold a different object. Additionally, in some instances, the multiple compliant arm mechanisms are configured to collaboratively and releasably hold a single object. In some instances, the different compliant arm mechanisms may have different functions. In one instance, one compliant arm mechanism is used to sense contact and pressure on a surface, and another compliant arm mechanism is used to place an object on the surface.

[0047] Back Figure 1 The aircraft control system 112 is configured to control various aircraft components and functions of the aircraft vehicle 100. For example, the aircraft control system 112 is configured to control the operation of various actuators (e.g., rotor thrusters 110, actuators of the compliant arm mechanism 102, sensors (e.g., optical sensors)) in response to commands from an operator, autopilot, navigation, or other advanced systems. During operation, the aircraft control system 112 is configured to dynamically (i.e., in real-time or near real-time) and independently adjust the thrust from each of the rotor thrusters 110 to control the roll, pitch, or yaw of the aircraft vehicle during various phases of flight (e.g., takeoff, flight, and landing). In one example, the aircraft control system 112 individually changes the speed (revolutions per minute (RPM)) of the rotor thrusters 110 to control the flight of the aircraft vehicle 100.

[0048] The aircraft control system 112 includes one or more processors communicatively connected to one or more storage devices. The one or more processors are configured to execute instructions stored in the one or more storage devices. For example, the one or more processors may be configured to execute instructions that are part of one or more applications, services, programs, routines, libraries, objects, components, data structures, or other logical constructs. The one or more processors may be configured to execute software instructions. Additionally or alternatively, the one or more processors may be configured to execute hardware or firmware instructions. The one or more processors may be single-core or multi-core, and the instructions executed thereon may be configured for sequential, parallel, and / or distributed processing. The one or more storage devices may include volatile, non-volatile, dynamic, static, read / write, read-only, random access, sequential access, location-addressable, file-addressable, and / or content-addressable devices. Aspects of the one or more processors and the one or more storage devices may be integrated together into one or more hardware logic components. For example, such hardware logic components may include field-programmable gate arrays (FPGAs), application-specific integrated circuits (PASICs / ASICs), application-specific standard products (PSSPs / ASSPs), systems-on-a-chip (SOCs), and complex programmable logic devices (CPLDs).

[0049] The aircraft control system 112 may include various sensors, including a Global Positioning System (GPS), an inertial navigation system, and / or an inertial measurement unit (IMU) that may include one or more gyroscopes and / or accelerometers. These sensors indicate inertial stability data used to control the orientation of the aircraft 100. In some instances, the aircraft 100 may be equipped with cameras (e.g., optical instruments for recording or capturing images and / or video, including light detection and ranging (LIDAR) devices), audio equipment (e.g., microphones, echolocation sensors, etc.), and other sensors such as motion capture sensors, radio beacons, infrared sensors, acoustic sensors, etc.

[0050] In some instances, the aircraft control system 112 includes a wireless transceiver configured to conduct data communication between the aircraft 100 and a remote device (e.g., a smartphone, desktop computer, laptop computer, base station). For example, the wireless transceiver is configured to communicate with the remote device via a wireless network using one or more wireless standards, such as Bluetooth, Near Field Communication (NFC), Wi-Fi, etc. In some instances, the remote device facilitates monitoring and / or control of the aircraft 100. In other instances, the aircraft 100 may be partially or fully automated.

[0051] The aircraft control system 112 is configured to control the aircraft 100 to perform multiple operations associated with positioning the aircraft 100 relative to a surface (e.g., a wall). The aircraft control system 112 uses one or more sensors 122 of the compliant arm mechanism 102 to provide feedback for controlling the aircraft 100 relative to the surface. In some instances, the aircraft control system 112 is configured to place an object held by the compliant arm mechanism 102 onto a surface based on feedback provided by the one or more sensors 122.

[0052] Figure 10-12 are schematic diagrams of different example scenarios in which an aircraft interacts with a surface through a compliant arm mechanism. Figures 10A-10F This is a schematic diagram of an example scenario in which an aircraft 1000 places an object 1006 on a vertical surface 1002 via a compliant arm mechanism 1004.

[0053] exist Figure 10A In this scenario, the aircraft 1000 flies to an area adjacent to the vertical surface 1002. This area can be identified, for example, by optical sensors, beacons positioned on the surface, visual observation by a human controller, or other identification methods. Figure 10B In this configuration, an aircraft 1000 extends a compliant arm mechanism 1004 laterally toward a vertical surface 1002 beyond the periphery 1008 of its propulsion system 1010. The aircraft 1000 controls the propulsion system 1010 and / or the compliant arm mechanism 1004 such that the compliant arm mechanism 1004 contacts the vertical surface 1002 via an object 1006. The aircraft 1000 receives one or more sensor signals via one or more sensors 1012 instructing the compliant arm mechanism 1004 to contact the vertical surface 1002 via the object 1006. The aircraft 1000 determines the force at the location of contact with the vertical surface 1002 based on the one or more sensor signals. In some instances, the same sensors (one or more) are used to determine both contact and force. In other instances, different sensors are used to determine contact and force.

[0054] exist Figure 10C In this scenario, the aircraft 1000 rebounds from the vertical surface 1002 due to contact with the compliant arm mechanism 1004. The contact with the vertical surface 1002 causes a change in the orientation of the aircraft 1000 relative to the vertical surface 1002. The aircraft 1000 receives the rebound based on force characteristics determined by one or more sensor signals from one or more sensors 1012. In this scenario, although the compliant arm mechanism 1004 absorbs a certain degree of force from contact with the vertical surface 1002, the overall force is large enough to cause the aircraft 1000 to leave the vertical surface 1002. It should be noted that in some instances, the impedance control characteristics of the compliant arm mechanism can be selected so that the contact force is not excessive and interferes with the position of the aircraft.

[0055] In 10D, the aircraft 1000 controls one or more of the propulsion system 1010 and the compliant arm mechanism 1004 to move backward toward a vertical surface 1002, causing an object 1006 to contact the vertical surface 1002. Because the orientation of the aircraft 1000 changes due to the bounce, the object 1006 is no longer aligned flush with the vertical surface 1002, which is determined by the aircraft 1000 via sensor signals from one or more sensors 1012. Since the force generated due to the previous contact is known, the aircraft 1000 can control one or more of the propulsion system 1010 and the compliant arm mechanism 1004 based on this force to mitigate the disruptive force when the aircraft 1000 re-engages with the vertical surface. Rotating the hand 1014 of the compliant arm mechanism 1004 aligns the object 1006 with the vertical surface 1002. Depending on the configuration of the aircraft 1000, the hand 1014 can be actively rotated by a motor or passively rotated based on the control of the propulsion system 1010. Alternatively or additionally, the aircraft 1000 may reorient itself under the control of the propulsion system 1010 to help align the object 1006 with the vertical surface 1002. Based on one or more sensor signals indicative of the force exerted by the object 1006 on the vertical surface 1002 when it is placed on the vertical surface 1002, the aircraft 1000 controls one or more of the propulsion system 1010 and the compliant arm mechanism 1004 to control the force exerted by the object 1006 on the vertical surface 1002 during placement. In some instances, controlling the force exerted on the vertical surface 1002 during placement includes maintaining the force above a threshold force for at least a threshold time period. The threshold force and threshold time period can be set to appropriate levels to allow the object 1006 to attach to the vertical surface 1002.

[0056] In some instances, the force determined based on the contact between the compliant arm mechanism and the vertical surface can optionally be used by the aircraft to control flight stability. For example, if the aircraft is subjected to a lateral disturbance of ten Newtons (e.g., due to the contact surface), the aircraft can respond more quickly to the force measured by the compliant arm mechanism than to waiting for the center of mass position to be measured by sensors of the aircraft control system, so that the deviation due to the disturbance is large enough to compensate for the disturbance.

[0057] exist Figure 10E In this process, object 1006 is attached to vertical surface 1002. Aircraft 1000 releases object 1006 from compliant arm mechanism 1004 and moves compliant arm mechanism 1004 from an extended position to a retracted position within the periphery 1008 of the propulsion system 1010 of aircraft 1000. Figure 10FIn the middle, the aircraft 1000 controls the propulsion system 1010 to fly off the vertical surface 1002 to perform another task.

[0058] Figure 11A-11E This is a schematic diagram of an example scenario where an aircraft 1100 places an object 1106 on an upwardly inclined surface 1102 via a compliant arm mechanism 1104. Figure 11A In the middle, the aircraft 1100 flies to an area close to the upward-sloping surface 1102. Figure 11B In this configuration, an compliant arm mechanism 1104 extends laterally beyond the periphery 1108 of the propulsion system 1110 of the aircraft 1100, extending beyond the upwardly tilted surface. The aircraft 1100 controls one or more of the propulsion system 1110 and the compliant arm mechanism 1104 such that the compliant arm mechanism 1104 contacts the upwardly tilted surface 1102 via an object 1106. The aircraft 1100 receives one or more sensor signals 1112 instructing the compliant arm mechanism 1104 to contact the upwardly tilted surface 1102 via the object 1106. The aircraft 1100 determines the force at the point of contact with the upwardly tilted surface 1102 based on the one or more sensor signals.

[0059] exist Figure 11C The hand 1114 of the compliant arm mechanism 1104 rotates based on the determined force to align the object with the upwardly inclined plane. Depending on the configuration of the aircraft 1100, the hand 1114 can be actively rotated by a motor or passively rotated based on the control of the propulsion system 1110. Alternatively or additionally, the aircraft 1100 can reorient itself by controlling the propulsion system 1110 to help align the object 1106 with the inclined surface 1102. Based on one or more sensor signals indicating the force exerted by the object 1106 on the upwardly inclined surface 1102 when the object 1106 is placed on the upwardly inclined surface 1102, the aircraft 1100 controls the force exerted by the object 1106 on the upwardly inclined surface 1102 during the placement of the object 1106 on the upwardly inclined surface 1102.

[0060] exist Figure 11D In this configuration, object 1106 is attached to an upwardly inclined surface 1102. The aircraft 1100 releases object 1106 from the compliant arm mechanism 1104 and moves the compliant arm mechanism 1104 from an extended position to a retracted position within the periphery 1108 of the propulsion system 1110 of the aircraft 1100. Figure 11E In the middle, the aircraft 1100 controls the propulsion system 1110 to fly away from the upwardly tilted surface 1102 to return to the base or fly another mission.

[0061] Figures 12A-12CThis is a schematic diagram of an example scenario where an aircraft 1200 places an object 1206 on a vertical surface 1202 via a passive compliant arm mechanism 1204. In contrast to active movement between a retracted position and an extended position, the passive compliant arm mechanism 1204 is configured to extend laterally beyond the periphery 1208 of the propulsion system 1210 of the aircraft 1200 in a permanent manner. Figure 12A In the middle, aircraft 1200 flies to an area adjacent to vertical surface 1202. Figure 12B In this configuration, the aircraft 1200 controls the propulsion system 1210 to cause the passive compliant arm mechanism 1024 to contact the vertical surface 1202 via the object 1206. The aircraft 1200 receives one or more sensor signals via one or more sensors 1212 instructing the passive compliant arm mechanism 1204 to contact the vertical surface 1202 via the object 1206. The aircraft 1200 determines the force at the point of contact with the vertical surface 1202 based on the one or more sensor signals. Based on the one or more sensor signals instructing the force exerted by the object 1206 on the vertical surface 1202 when the object 1206 is placed on the vertical surface 1202, the aircraft 1200 controls the force exerted by the object 1206 on the vertical surface 1202 during the placement of the object 1206 on the vertical surface 1202. Figure 12C In this process, object 1206 is attached to vertical surface 1202, and aircraft 1200 controls propulsion system 1210 to fly off vertical surface 1202 to return to base or fly another mission.

[0062] Figure 13 This is a flowchart of an example method 1300 for controlling an aircraft including a compliant arm mechanism. For example, method 1300 can be achieved through... Figure 1 The illustrated aircraft vehicle 100 is in operation. At 1302, the propulsion system of the aircraft vehicle is controlled to fly the aircraft vehicle to a region adjacent to the surface. At 1304, one or more of the propulsion system and the compliant arm mechanism of the aircraft vehicle are controlled to contact the surface. The compliant arm mechanism is configured to passively or actively extend laterally beyond the periphery of the propulsion system to contact the surface. In some instances, controlling the compliant arm mechanism includes moving the compliant arm mechanism from a retracted position to an extended position via an extendable connector. In some instances, controlling the compliant arm mechanism includes moving a toggle connector to control the force applied to the surface by the hand of the compliant arm mechanism.

[0063] At 1306, one or more sensor signals are received from one or more sensors. For example, the sensors(s) may be located on an aircraft, a surface, or other aircraft. The one or more sensor signals indicate the contact surface of the compliant arm mechanism. At 1308, the force at the aircraft's compression surface is determined based on the one or more sensor signals.

[0064] In some instances, at 1310, optionally, the propulsion system of the aircraft can be controlled to orient the aircraft relative to a surface based on forces determined by one or more sensor signals. For example, the propulsion system can be controlled to orient the surface of the compliant arm mechanism parallel to the surface. In another instance, the compliant arm mechanism can be controlled to orient the surface of the compliant arm mechanism parallel to the surface.

[0065] In some instances, at 1312, optionally, one or more of the propulsion system and compliant arm mechanism may be controlled based on force determined by one or more sensor signals, such that the compliant arm mechanism compresses the surface to stabilize the aircraft.

[0066] In some instances, the compliant arm mechanism can be configured to releasably hold an object. Thus at 1314, optionally, after receiving one or more sensor signals indicating that the object is in contact with a surface, one or more of the propulsion system and the compliant arm mechanism can be controlled to control the force exerted by the object on the surface during the placement of the object on the surface, based on one or more sensor signals indicating the force exerted by the object on the surface when the object is placed on the surface.

[0067] The concepts described in this article can be broadly applied to any suitable type of aircraft, including fixed-wing aircraft and manned and unmanned aircraft.

[0068] Furthermore, this disclosure includes examples pursuant to the following provisions:

[0069] Clause 1. A method for controlling an air vehicle (1300), the method comprising:

[0070] Control (1302) the propulsion system of the aircraft to make the aircraft fly to an area adjacent to the surface;

[0071] Controlling one or more of the propulsion system and compliant arm mechanism of the (1304) aircraft vehicle such that the compliant arm mechanism contacts a surface, the compliant arm mechanism being configured to extend laterally beyond the periphery of the propulsion system;

[0072] The sensor receives (1306) one or more sensor signals indicating that the compliant arm mechanism is in contact with the surface; and

[0073] Based on the signals from one or more sensors, the force at the extrusion surface of the aircraft (1308) is determined.

[0074] Clause 2. In accordance with the method of Clause 1 (1300), it further includes:

[0075] A force-controlled (1310) propulsion system based on one or more sensor signals is used to orient an aircraft relative to a surface.

[0076] Clause 3. The method (1300) according to Clause 1 or 2, wherein the compliant arm mechanism is configured to releasably hold an object, wherein one or more sensor signals indicate that the object is in contact with a surface, and wherein the method further includes, upon receiving one or more sensor signals indicating that the object is in contact with a surface, controlling (1314) one or more of the propulsion system and the compliant arm mechanism to control the force exerted by the object on the surface during the placement of the object on the surface, based on one or more sensor signals indicating the force exerted by the object on the surface when the object is placed on the surface.

[0077] Clause 4. The method (1300) according to Clause 3, wherein controlling the force applied to the surface during the placement of the object on the surface includes maintaining the force above a threshold force for at least a threshold time period.

[0078] Clause 5. The method (1300) according to any one of Clauses 1-4, wherein controlling the compliant arm mechanism includes moving the compliant arm mechanism from the retracted position to the extended position via an extendable connector.

[0079] Clause 6. The method (1300) according to any one of Clauses 1-5, wherein the compliant arm mechanism includes a column, an elbow joint connected to the column, and a hand connected to the elbow joint, the elbow joint including at least one degree of motion freedom, and wherein controlling the compliant arm mechanism includes moving the elbow joint to control the force applied by the hand to a surface.

[0080] Clause 7. An aircraft carrier (100) comprising:

[0081] Skeleton (104);

[0082] The propulsion system (109) is connected to the frame (104); and

[0083] A compliant arm mechanism (102) is connected to the frame (104), the compliant arm mechanism (102) including a column (114), an elbow joint (120) connected to the column, and a hand (116) connected to the elbow joint (120), wherein the compliant arm mechanism (102) includes at least one degree of freedom of motion, and the compliant arm mechanism (102) is configured to extend laterally beyond the periphery of the propulsion system (109) to contact the surface.

[0084] Clause 8. The aircraft (100) pursuant to Clause 7 further includes:

[0085] A sensor configured to output a sensor signal indicating the force applied to a surface by the compliant arm mechanism; and

[0086] The controller is configured as follows

[0087] One or more of the control propulsion system (109) and the compliant arm mechanism (102) cause the compliant arm mechanism (102) to contact the surface.

[0088] The sensor (122) receives one or more sensor signals indicating that the compliant arm mechanism (102) is in contact with the surface, and

[0089] The force at the extrusion surface of the aircraft (100) is determined based on signals from one or more sensors.

[0090] Clause 9. An aircraft (100) pursuant to Clause 8, wherein a controller (112) is configured to control a propulsion system (109) based on force determined by one or more sensor signals to orient the aircraft relative to a surface.

[0091] Clause 10. An aircraft according to Clause 8 or 9, wherein the hand (116) is configured to releasably hold an object, wherein one or more sensor signals indicate that the object is in contact with a surface, and wherein the controller (112) is configured, upon receiving one or more sensor signals indicating that the object is in contact with a surface, to control one or more of the propulsion system (109) and the compliant arm mechanism (102) to control the force exerted by the object on the surface during the placement of the object on the surface, based on one or more sensor signals indicating the force exerted by the object on the surface when the object is placed on the surface.

[0092] Clause 11. An aircraft (100) pursuant to any one of Clauses 7-10, wherein the compliant arm mechanism (102) includes an extendable connector (118) configured to move between a retracted position and an extended position, wherein in the extended position the compliant arm mechanism (102) extends laterally beyond the periphery of the propulsion system.

[0093] Clause 12. An aircraft (100) pursuant to any one of Clauses 7-11, wherein the compliant arm mechanism (102) comprises one or more of a spring (308) and a damper to provide passive compliance.

[0094] Clause 13. An aircraft (100) under any of Clauses 7-12, wherein the compliant arm mechanism (102) includes one or more motor-driven actuators (208) to provide active compliance.

[0095] Clause 14. An aircraft (100) pursuant to any of Clauses 7-13, wherein the toggle connector (120) is passively compliant.

[0096] Clause 15. An aircraft (100) pursuant to any of Clauses 7-14, wherein the toggle connector (120) comprises at least two degrees of freedom of motion.

[0097] Clause 16. A compliant arm mechanism (102) removably attached to an aircraft carrier (100) frame (1040), the compliant arm mechanism (102) comprising:

[0098] String (115);

[0099] The elbow connector (120) connected to the string (115), and

[0100] The hand (116) connected to the toggle connector (120) has an compliant arm mechanism (102) including at least one degree of freedom of motion, and the compliant arm mechanism (102) is configured to extend laterally beyond the periphery of the propulsion system (109) of the aircraft (100) to contact the surface.

[0101] Clause 17. The compliant arm mechanism (102) according to Clause 16, wherein the hand (116) is configured to releasably hold an object, and the compliant arm mechanism (106) is configured to extend laterally beyond the periphery of the propulsion system (109) to place the object on a surface.

[0102] Clause 18. The compliant arm mechanism (102) pursuant to Clause 16 or 17, wherein the column (115) includes an extendable connector (120) configured to move between a retracted position and an extended position, wherein in the extended position the compliant arm mechanism (102) extends laterally beyond the periphery of the propulsion system (109).

[0103] Clause 19. A compliant arm mechanism (102) pursuant to any of Clauses 16-18, wherein the compliant arm mechanism (102) includes one or more springs (308) and dampers to provide passive compliance.

[0104] Clause 20. A compliant arm mechanism (102) pursuant to any one of Clauses 16-19, wherein the compliant arm mechanism (102) includes one or more motor-driven actuators (208) to provide active compliance.

[0105] This disclosure includes all novel and non-obvious combinations and sub-combinations of the various features and techniques disclosed herein. The various features and techniques disclosed herein are not necessary for all instances of this disclosure. Furthermore, the various features and techniques disclosed herein may define patentable subject matter beyond the disclosed instances, and utility may be found in other embodiments not expressly disclosed herein.

Claims

1. A method of controlling an aerial vehicle, the aerial vehicle comprising a compliant arm mechanism configured to extend laterally beyond a perimeter of a propulsion system of the aerial vehicle and releasably hold a plurality of objects for placement at different locations, the method comprising: controlling the propulsion system of the aerial vehicle to fly the aerial vehicle to a first region proximate a first surface; controlling an extendable link of the compliant arm mechanism of the aerial vehicle to extend the compliant arm mechanism so that a first object of the plurality of objects contacts the first surface, wherein the plurality of objects are held by a storage, wherein the storage is configured so that when the first object is placed, a second object in the storage is moved to a location to be placed; receiving, by a sensor, one or more sensor signals indicative of the compliant arm mechanism contacting the first surface; determining, based on the one or more sensor signals, a force at which the aerial vehicle is pressing against the first surface; controlling, based on the force determined from the one or more sensor signals, the propulsion system to orient the aerial vehicle relative to the first surface; controlling, based on the one or more sensor signals, the extendable link of the compliant arm mechanism to control a force exerted on the first surface by the first object during placement of the first object on the first surface; controlling the propulsion system of the aerial vehicle to fly the aerial vehicle to a second region proximate a second surface; controlling an extendable link of the compliant arm mechanism of the aerial vehicle to extend the compliant arm mechanism so that a second object of the plurality of objects contacts the second surface; receiving, by the sensor, one or more sensor signals indicative of the compliant arm mechanism contacting the second surface; determining, based on the one or more sensor signals, a force at which the aerial vehicle is pressing against the second surface; controlling, based on the force determined from the one or more sensor signals, the propulsion system to orient the aerial vehicle relative to the second surface; controlling, based on the one or more sensor signals, the extendable link of the compliant arm mechanism to control a force exerted on the second surface by the second object during placement of the second object on the second surface.

2. The method of claim 1, wherein controlling the force exerted on the first surface during placement of the first object on the first surface comprises maintaining the force above a threshold force for at least a threshold period of time.

3. An aerial vehicle comprising a chassis; a propulsion system connected to the chassis; a compliant arm mechanism connected to the chassis, the compliant arm mechanism configured to extend laterally beyond a perimeter of the propulsion system to contact a surface and releasably hold a plurality of objects for placement at different locations, the compliant arm mechanism comprising an extendable link, a tube column connected to the extendable link, an elbow link connected to the tube column, and a hand connected to the elbow link, the hand configured to releasably hold a first object of the plurality of objects; and a sensor. a storage configured to hold the plurality of objects, wherein the storage is configured such that when the first object is placed, a second object in the storage is moved to a position to be placed; a sensor configured to output a sensor signal indicative of a force exerted by the compliant arm mechanism on the surface; and a controller configured to control the extendable link of the compliant arm mechanism to extend the compliant arm mechanism such that the first object contacts the surface, receive, by the sensor, one or more sensor signals indicative of the compliant arm mechanism contacting the surface, and determine, based on the one or more sensor signals, a force at which the aerial vehicle is pressing against the surface; control, based on the one or more sensor signals, the extendable link of the compliant arm mechanism to control a force exerted by the first object on the surface during placement of the first object on the surface.

4. The aerial vehicle of claim 3, wherein the controller is configured to control the propulsion system to orient the aerial vehicle relative to the surface based on the force determined from the one or more sensor signals.

5. A compliant arm mechanism removably attached to a skeleton of an aerial vehicle, the compliant arm mechanism comprising: a tube column configured to releasably hold a plurality of objects; an elbow link connected to the tube column, a hand connected to the elbow link, the hand configured to releasably hold a first object of the plurality of objects; and an extendable link connected to the tube column and configured to extend the compliant arm mechanism such that the first object contacts a surface adjacent to the aerial vehicle, wherein the extendable link of the compliant arm mechanism is electronically controllable to control a force exerted by the first object on the surface during placement of the first object on the surface by the aerial vehicle.

6. The compliant arm mechanism of claim 5, wherein the compliant arm mechanism is configured to extend laterally beyond a perimeter of a propulsion system of the aerial vehicle to place one of the plurality of objects on the surface.

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