Accurate positioning of an end effector on housing structure coupled to aerial vehicle

Abstract

A system for steering an end effector on a tether comprises a housing structure with a set of fan blades, a first motor to rotate the fan blades, a second motor to change the orientation of the fan blades for steering, a reaction wheel, and a third motor to rotate the reaction wheel for yaw control. One or more sensors are coupled to the housing structure and provide signals to a controller. The controller operates the motors in response to the sensor signals to precisely guide the housing structure to a target location for pickup or delivery of an item. The system may be deployed from an aerial vehicle via a winch and tether and can interact with ground-based tags to determine its position.

Description

PATENTAttorney Docket No. 107723-1542732-P00528WO01Client Ref. No. P00528WO01ACCURATE POSITIONING OF AN END EFFECTOR ON HOUSING STRUCTURE COUPLED TO AERIAL VEHICLECROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application is a PCT application which claims priority to U. S. Provisional Application No. 63 / 778,287, filed on March 26, 2025, which is herein incorporated by reference in its entirety for all purposes.BRIEF SUMMARY

[0002] Embodiments of the invention are directed to a system for precisely controlling the position of an end effector (e.g., a hook, grabber, etc.) at a bottom of a housing structure. The housing structure can be at the end of a tether deployed from an aerial vehicle such as a drone. The housing structure houses a set of fan blades, a first motor to rotate the fan blades about a first axis to generate thrust, and a second motor to move the fan blades about a second, orthogonal axis to steer the housing structure. A third motor is configured to rotate a reaction wheel (e.g., a flywheel) to control the yaw and stability of the housing structure and the end effector while the housing structure and the end effector are in the air. One or more sensors, such as ultrawideband sensors, are coupled to the housing structure and provide signals to a controller. The controller uses these signals to operate the motors and guide the housing structure to a predetermined location.

[0003] One embodiment of the invention includes a system comprising: a housing structure; a set of fan blades in the housing structure; a first motor operationally coupled to the set of fan blades and configured to rotate the set of fan blades about a first axis; a second motor operationally coupled to the set of fan blades, the second motor configured to cause the set of fan blades to move about a second axis orthogonal to the first axis; a reaction wheel within the housing structure; a third motor configured to rotate the reaction wheel; one or more sensors coupled to the housing structure; and a controller, wherein the controller is configured to control operation of the first motor, the second motor, and the third motor in response to signals from the one or more sensors.179528296V.1

[0004] Another embodiment of the invention includes a method of using a system comprising a housing structure, a set of fan blades in the housing structure, a first motor operationally coupled to the set of fan blades and configured to rotate the set of fan blades about a first axis, a second motor operationally coupled to the set of fan blades, the second motor configured to cause the set of fan blades to move about a second axis orthogonal to the first axis, a reaction wheel within the housing structure, a third motor configured to rotate the reaction wheel, one or more sensors coupled to the housing structure, and a controller, wherein the controller is configured to control operation of the first motor, the second motor, and the third motor in response to signals from the one or more sensors. The method comprises: determining, by the one or more sensors, a location underneath the housing structure; and controlling, by the controller, in response to signals from the one or more sensors, the first motor, the second motor, and the third motor to guide the housing structure proximate the location.

[0005] Another embodiment of the invention includes a method for making a system, the method comprising: assembling a set of fan blades and a first motor, the first motor operationally coupled to the set of fan blades and configured to rotate the set of fan blades about a first axis; coupling a second motor to the set of fan blades, the second motor configured to cause the set of fan blades to move about a second axis orthogonal to the first axis; assembling a reaction wheel and a third motor configured to rotate the reaction wheel; electrically coupling a controller to the first motor, the second motor, and the third motor to one or more sensors; and assembling the set of fan blades, the first motor, the second motor, the third motor, the reaction wheel, and the controller in a housing structure.

[0006] These and other embodiments of the invention are described in detail below.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] FIG. 1 shows a diagram illustrating the overall environment in which a system according to an embodiment of the invention operates.

[0008] FIG. 2 shows a diagram illustrating some of the internal components of the steerable system according to an embodiment.

[0009] FIG. 3 shows a block diagram of some of system components according to an embodiment.279528296V.1

[0010] FIG. 4 shows a diagram of the system interacting with an item to be picked up or delivered according to an embodiment.DETAILED DESCRIPTION

[0011] Embodiments of the present invention is directed to the field of unmanned aerial vehicle (UAV) or drone delivery. A number of unsolved technical and business problems exist in this field. One major challenge relates to the pickup of goods, specifically the exchange of items between the ground and the air in a manner that is compatible with existing merchant operations, is feasible within merchant capital constraints, does not require significant or burdensome infrastructure modifications on a merchant's property, and exposes the public to an acceptable level of risk and noise, especially considering the operation of an approximately 50-pound aircraft.

[0012] Another major challenge lies in the precision of the delivery itself. Delivery accuracy is often defined by a statistical measure, such as a circle on the ground that contains 99% of all deliveries. Wind is a primary factor that increases the size of this circle, reducing the number of properties a drone can successfully and safely deliver to. While reducing the drone's altitude during drop-off can mitigate wind effects, it significantly increases noise exposure and safety risks to the public. Embodiments of the invention described herein address these problems with a novel, cost-effective, and highly scalable solution.

[0013] Embodiments of the invention provide for a steerable end effector on a housing structure that has positional awareness relative to a target ground station. This allows an aerial vehicle to remain at a high, safe altitude (e.g., 200 feet or more) while the end effector and housing structure, attached to the end of a tether, performs precise maneuvers for pickup or delivery. This approach provides significant benefits, including the ability to perform a precision hover pickup, which enables a very small and low-cost ground infrastructure at merchant locations. Embodiments of the invention are expected to be over one hundred times less expensive and require less than ten times the space as compared to other solutions. The high operational altitude of the drone is inherently safer, providing sufficient time and height for a parachute to deploy in the unlikely event of a flight failure.

[0014] Some embodiments of the invention include a three-dimensional sensing anchor on the end of a winch, such that this “active hook” has positional awareness of itself relative to the ground station at which it is intending to dock. In some embodiments, a ground station can379528296V.1be defined in part by 3 to 4 tags (e.g., ultrawideband tags), which can be powered. As the three-dimensional anchor gets within close proximity (~10 m or less) of a target location, it begins a closed loop navigation process based upon its sensed relative position.

[0015] FIG. 1 shows a diagram illustrating the overall system and its operating environment. The system includes ground hardware 150 and an aerial vehicle 100. The aerial vehicle 100, which may be a drone, includes a winch 102. A tether 106 is coupled to the winch 102 at one end and to the active end effector hardware 104 at the other. The active end effector hardware 104 can be a self-contained system that includes a propulsion apparatus 108 including a housing structure 208, one or more sensors 110 attached to the housing structure 208, and an end effector 112, such as a hook, attached to a bottom portion of the housing structure 208. In this example, the housing structure 208 has a cylindrical shape. However, it can have other shapes in other embodiments (e.g., a parallelepiped).

[0016] FIG. 1 also shows a propulsion apparatus 108. The propulsion apparatus 108 can include a number of motors, a fan, a rotating turntable, a reaction wheel, and a controller. As will be explained in further detail below, these features can allow the active end effector hardware 104 to move in a desired manner.

[0017] The end effector 112 can be any suitable device, which can used be to manipulate an object in the air and on the ground. Examples of end effectors include hooks, magnets, grabbers, containers (e.g., a scooper), and the like.

[0018] The ground hardware 150 is located on a stationary platform 152. The ground hardware includes a plurality of tags 154, for instance, three to four ultrawideband (UWB) tags, which may be permanently powered. These tags 154 define a target area and create a virtual center 156, which is the in-plane center of the plane defined by the tags 154. The sensor 110 on the active end effector hardware 104 is configured to communicate with these tags 154. As the active end effector hardware 104 gets within a predetermined distance (e.g., 10 meters or less) of the platform 152, the sensor 110 detects the tags 154 and initiates a closed-loop navigation process to autonomously guide the end effector 112 to the virtual center 156. This virtual center 156 can represent the target location for the end effector 112 (e.g., the hook).

[0019] The one or more sensors 110 can include one or more ultrawideband sensors, each of which may include an ultrawideband transceiver and an ultrawideband processor. In embodiments of the invention, an ultrawideband sensor, located in the active end effector hardware, sends out a very' short, coded radio pulse (an ultrawideband signal). The UWB tags 479528296V.1on the ground station receive this pulse and instantly send a reply pulse back. The ultrawideband sensor receives the reply pulse and then measures the incredibly short time that elapsed between sending the initial pulse and receiving the reply. This is known as " Time-of- Flight" (ToF). By getting distance readings from at least three or four tags on the ground, the system can triangulate (or more accurately, trilaterate) its exact 3D position in space with high accuracy.

[0020] While the use of ultrawideband (UWB) sensors and tags is described as a preferred embodiment, it will be apparent to those skilled in the art that other sensing modalities can be used to achieve the same closed-loop positional guidance without departing from the scope of the invention. For example, the system could utilize a vision-based guidance system. In such an embodiment, the sensor on the housing structure would be a digital camera, and the tags on the ground would be passive visual markers, such as high-contrast fiducial markers (e.g., QR codes) or a simple geometric pattern. An image processing algorithm executed by the controller would analyze the video feed from the camera to identify the marker, calculate its position and orientation relative to the end effector, and guide the system to the target. Alternatively, an infrared (IR) guidance system could be employed, wherein the sensor is an IR camera and the ground tags are active IR-emitting beacons (e.g., LEDs). This approach would offer enhanced robustness in various lighting conditions, including darkness. In another embodiment, a laser-based system could be used, where a LIDAR sensor or an array of laser time-of-flight sensors on the housing structure would detect passive retroreflectors on the ground to determine position with very high precision. Further still, the system could use high-precision GPS, such as a Real-Time Kinematic (RTK) GPS system, where a stationary base station on the ground provides correction data to a rover GPS unit on the end effector to achieve centimeter-level accuracy. Finally, a magnetic guidance system could be used for short-range homing, wherein one or more magnetometers on the end effector detect the field from one or more powerful permanent magnets or electromagnets at the target location.

[0021] FIG. 2 shows a view of some the internal components of the active end effector hardware 104 and the propulsion apparatus 108 in FIG. 1. The components are contained within the housing structure 200. The housing structure 208 may comprise an upper portion 208A, which can be defined at least in part by a protective cage, and a lower portion 208B, which can be defined at least in part by solid walls to protect the internal components. The housing structure 208 can be made of any suitable material including plastic or metal.579528296V.1

[0022] A set of fan blades 210 is located within the upper portion 208A of the housing structure 200. A first motor (shown as 310 in FIG. 3) is operationally coupled to the set of fan blades 210 and is configured to rotate them about a hub 209 aligned with a first axis 202 to generate the thrust required to steer the system. The set of fan blades 210 can be mounted on a turntable 220 and secured to it by a vertical axial rod (not shown) along a second axis 204. A second motor (shown as 312 in FIG. 3) is configured to rotate the axial rod and the turntable 220, and consequently the set of fan blades 210 about the second axis 204. This rotation causes the fan assembly to move about a second axis 204, which is orthogonal to the first axis 202. By rotating the turntable 220, the direction of the thrust generated by the fan blades 210 can be vectored, allowing the housing structure 200 to be steered horizontally. To permit continuous, 360-degree rotation of the turntable and fan assembly without tangling wires, slip rings (not shown) may be used to provide power and data connections.

[0023] To counteract rotational loads from the steering motor (e.g., the second motor) and to actively control the yaw of the housing structure 200, the system includes a reaction wheel 230 (also referred to as a flywheel). A third motor (shown as 314 in FIG. 3) is configured to rotate the reaction wheel 230. By precisely controlling the rotational speed of the reaction wheel 230, an onboard controller can manage the orientation of the housing structure 200 about its vertical axis.

[0024] More specifically, the third motor can be used for stability and fine-tuned rotational control (yaw). By precisely speeding up or slowing down the (heavy) spinning reaction wheel, it creates a counter-torque that rotates the housing structure 200 and the active end effector hardware around its vertical axis. This prevents the device from spinning out of control and allows it to precisely aim its sensors and face the correct direction for pickup or delivery.

[0025] FIG. 3 shows a block diagram of exemplary hardware in the propulsion apparatus 300 according to embodiments of the invention. In the propulsion apparatus 300, a controller 315 is electrically coupled to the first motor 310, the second motor 312, and the third motor 314. A position sensor 320, which corresponds to sensor 110 in FIG. 1, provides signals to the controller 315. The position sensor 320 may be one or more ultrawideband sensors, such as a TRR 250 LAVB transceiver, capable of detecting the tags 154 on the ground. A power source 316, such as an onboard battery module, supplies power to the first, second, and third motors 310, 312, 314 and the controller 315. The battery may be trickle-charged via a powered679528296V.1tether from the aerial vehicle 100. In other embodiments, the power source 316 can be in the form of a power line in the tether from the aerial vehicle. The system may also include a computer readable medium in a memory within or coupled to the controller 315 that comprises code, executable by a processor unit in the controller 315 to perform the methods described herein.

[0026] The system includes a communication interface 318 for communicating with the main aerial vehicle 100. The physical interface between the sensing system and propulsion apparatus may be serial (UART). The system's application programming interface (API) can communicate several states, such as [no tag detected], [tag lock not achieved], or [tag lock achieved with the vector to the virtual center]. The physical form factor of the UWB sensor and its associated application processor may be compact, for example, within the boundary of a standard deck of cards.

[0027] In some embodiments, the components of the propulsion apparatus 300 can be in the housing structure 200. In other embodiments, some components in the propulsion apparatus 300 can be outside of the housing structure 208.

[0028] FIG. 4 shows the system in a use case, such as picking up or delivering an item. A tether 280 connects the upper portion 208A of the housing structure to the aerial vehicle. The end effector 112, shown as a hook, is attached to a lower portion 208B of the housing structure. The housing structure is comprised of an upper portion 208A and a lower portion 208C. The upper portion 208A can be defined in part by a cage to allow the passage of air to and from the set of fan blades in the upper portion 208A of the housing structure, and an upper cap 208C. A tether 106 is attached to the upper cap 208C.

[0029] The end effector 112 can be configured to capture an item, such as a container 290. The container 290 may be a delivery bag with a body portion 290B and handles 290A that can be easily engaged by the end effector 112. The container 290 may contain food items for delivery or non-perishable items for delivery or returns.

[0030] In an embodiment, a method of using the system is described. The process begins when the system, suspended by the tether from the aerial vehicle, is lowered toward a target location. The one or more sensors on the housing structure begin determining the location underneath the housing structure. For example, the sensor 110 (e.g., a UWB sensor) communicates with the plurality of tags 154 on the ground to determine the precise vector to the virtual center 156. The sensors provide this location data as signals to the controller. The 779528296V.1controller, in response to these signals, then actively controls the first, second, and third motors to guide the housing structure and the attached end effector proximate to the location. The controller may command the first motor to increase or decrease thrust, command the second motor to rotate the turntable to vector the thrust in the correct direction, and command the third motor to adjust the speed of the reaction wheel to maintain the correct heading and counteract any unwanted rotation. This closed-loop control continues until the end effector is aligned with the predetermined location.

[0031] The method may further comprise using the end effector to pick up or drop off an item at the location. For a pickup operation, the controller would guide the end effector 112 to engage with an item, such as the handles 290A of the container 290. For a delivery operation, the controller would guide the end effector to the location and then actuate it to release the item.

[0032] In another embodiment, a method for making the system is described. The method begins with the sub-assembly of the propulsion and control components. A set of fan blades and a first motor are assembled, where the first motor is operationally coupled to the fan blades to rotate them about hub aligned with a first axis. A second motor is coupled to the fan blades, for example by mounting the first motor and fan blades on a turntable that is driven by the second motor, such that the second motor can cause the fan blades to move about a second, orthogonal axis. Concurrently, a reaction wheel and a third motor are assembled, with the third motor configured to rotate the reaction wheel. The next step involves electrically coupling a controller to the first motor, second motor, third motor, and to the one or more sensors. Finally, these assembled components---the set of fan blades, the three motors, the reaction wheel, and the controller — are assembled and secured within the housing structure to produce the completed system. One or more sensors can be provided within or may be attached to the housing structure.

[0033] A number of uses cases can be envisioned. For example, a merchant pickup box which takes up no more than 1’ by 1’ on the ground can be used. It can be collapsed down for storage when it is not in use (e.g., to a height no more than 5’). It can be deployed outside to enable a near-passive implementation of a ground to air interface for payloads. While possible to do without a steerable end, a large safety keep out zone would have to be placed around the ground hardware as to reliably hit the same capture area for the end effector on the end of the winch. This would require an altitude for which it is difficult to safety control the velocity of879528296V.1the aircraft in the event of a failure. It would also present an annoying and frustration experience for nearby people given the noise exposure and threat of harm.

[0034] Another use case is the active handoff between a drone and a ground robot. With a steerable end, and a ground robot (i.e., city hopper), one could “steer” the package into the ground robot’s payload receptacle, and complete the last few feet of the delivery without any additional mechanism to do the transfer.

[0035] A final use case is the actual delivery of the product to a doorstep. With precision guidance technology, it is possible to land on a “dinner plate” at an altitude of -200 feet. This enables a premium customer experience.

[0036] One advantage of embodiments of the invention can include the ability to do a hover pickup with precision, which enables very a small ground infrastructure at a merchant or other entity. To date, there are no drone delivery solutions that enables a safe, low footprint, low cost pickup modality at a merchant that is also operationally tractable. With a steerable end, embodiments of the invention can use a mechanical capture area of about 1 meter in diameter, which makes it tractable to set up a ground interfacing hardware anywhere with access to the sky and immediately have access to a drone delivery platform, without ever coming within 200 feet from a drone. It also requires little or no additional infrastructure, and is inherently safe due to the high altitude at which the drone is operating (e.g., there is sufficient time and height for a parachute to deploy in the highly unlikely event of a failure of the drone during flight).

[0037] Any of the software components or functions described in this application may be implemented as software code to be executed by a processor using any suitable computer language such as, for example, Java, C, C++, C#, Objective-C, Swift, or scripting language such as Perl or Python using, for example, conventional or object-oriented techniques. The software code may be stored as a series of instructions or commands on a computer readable medium for storage and / or transmission, suitable media include random access memory (RAM), a read only memory (ROM), a magnetic medium such as a hard-drive or a floppy disk, or an optical medium such as a compact disk (CD) or DVD (digital versatile disk), flash memory, and the like. The computer readable medium may be any combination of such storage or transmission devices.

[0038] Such programs may also be encoded and transmitted using carrier signals adapted for transmission via wired, optical, and / or wireless networks conforming to a variety 979528296V.1of protocols, including the Internet. As such, a computer readable medium according to an embodiment of the present invention may be created using a data signal encoded with such programs. Computer readable media encoded with the program code may be packaged with a compatible device or provided separately from other devices (e.g., via Internet download). Any such computer readable medium may reside on or within a single computer product (e.g., a hard drive, a CD, or an entire computer system), and may be present on or within different computer products within a system or network. A computer system may include a monitor, printer, or other suitable display for providing any of the results mentioned herein to a user.

[0039] The above description is illustrative and is not restrictive. Many variations of the invention will become apparent to those skilled in the art upon review of the disclosure. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the pending claims along with their full scope or equivalents.

[0040] One or more features from any embodiment may be combined with one or more features of any other embodiment without departing from the scope of the invention.

[0041] As used herein, the use of "a," "an," or "the" is intended to mean "at least one," unless specifically indicated to the contrary.1079528296V.1

Claims

WHAT IS CLAIMED IS:

1. A system comprising:a housing structure;a set of fan blades in the housing structure;a first motor operationally coupled to the set of fan blades and configured to rotate the set of fan blades about a first axis;a second motor operationally coupled to the set of fan blades, the second motor configured to cause the set of fan blades to move about a second axis orthogonal to the first axis;a reaction wheel within the housing structure;a third motor configured to rotate the reaction wheel;one or more sensors coupled to the housing structure; anda controller, wherein the controller is configured to control operation of the first motor, the second motor, and the third motor in response to signals from the one or more sensors.

2. The system of claim 1, further comprising a turntable within the housing structure, wherein the set of fan blades is attached to the turntable via an axial rod parallel to the second axis.

3. The system of claim 1, wherein the housing structure further comprises an upper portion and a lower portion, the upper portion defined in part by a cage and the lower portion is defined in part by solid walls.

4. The system of claim 3, further comprising:an end effector attached to the lower portion of the housing structure, the end effector configured to capture an item or deliver the item to a location.

5. The system of claim 4, wherein the end effector comprises a hook, a magnet, or a grabber.

6. The system of claim 1, wherein the one or more sensors comprise one or more ultrawideband sensors.1179528296V.

17. The system of claim 1, wherein the first motor, the second motor, the third motor, and the controller are in the housing structure.

8. The system of claim 1, wherein the housing structure further comprises an upper portion and a lower portion, and the system further comprises:a tether coupled to the upper portion of the housing structure.

9. The system of claim 8, further comprising:an end effector attached to the lower portion of the housing structure, the end effector configured to capture an item or deliver the item to a predetermined location below the housing structure, andwherein the controller is configured to control operation of the first motor, the second motor, and the third motor in response to signals from the one or more sensors in order to align the end effector with the predetermined location.

10. The system of claim 9, further comprising:a plurality of tags disposed proximate the predetermined location, the plurality of tags capable of communicating with the one or more sensors to allow the one or more sensors to determine the predetermined location with respect to one or more positions of the one or more sensors.

11. The system of claim 10, the system further comprises:an aerial vehicle, wherein a first end of the tether is coupled to the upper portion of the housing structure and a second end of the tether is coupled to the aerial vehicle via a winch in the aerial vehicle.

12. The system of claim 11, wherein the aerial vehicle is a drone.

13. The system of claim 12, wherein the item is a container comprising another item to be delivered.

14. The system of claim 13, wherein the first motor is configured to control a thrust to push the housing structure horizontally, the second motor is configured to 1279528296V.1control an orientation of the set of fan blades to steer the housing structure, and the third motor is configured to control the reaction wheel within the housing structure to control yaw rotation of the housing structure.

15. The system of claim 1, further comprising a power source configured to supply power to the first motor, the second motor, the third motor, and the controller.

16. The system of claim 15, wherein the power source is a battery.

17. A method of using a system comprising a housing structure, a set of fan blades in the housing structure, a first motor operationally coupled to the set of fan blades and configured to rotate the set of fan blades about a first axis, a second motor operationally coupled to the set of fan blades, the second motor configured to cause the set of fan blades to move about a second axis orthogonal to the first axis, a reaction wheel within the housing structure, a third motor configured to rotate the reaction wheel, one or more sensors coupled to the housing structure, and a controller, wherein the controller is configured to control operation of the first motor, the second motor, and the third motor in response to signals from the one or more sensors the method comprising:determining, by the one or more sensors, a location underneath the housing structure; andcontrolling, by the controller, in response to signals from the one or more sensors, the first motor, the second motor, and the third motor to guide the housing structure proximate the location.

18. The method of claim 17, wherein the system comprises end effector coupled to the housing structure, and the method further comprises:using the end effector to pick up or drop off an item at the location.

19. The method of claim 18, wherein the item is in a container.

20. A method for making a system, the method comprising: assembling a set of fan blades and a first motor, the first motor operationally coupled to the set of fan blades and configured to rotate the set of fan blades about a first axis;1379528296V.1coupling a second motor to the set of fan blades, the second motor configured to cause the set of fan blades to move about a second axis orthogonal to the first axis;assembling a reaction wheel and a third motor configured to rotate the reaction wheel;electrically coupling a controller to the first motor, the second motor, and the third motor to one or more sensors; andassembling the set of fan blades, the first motor, the second motor, the third motor, the reaction wheel, and the controller in a housing structure.1479528296V.1

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