Energy harvesting roller assembly

An energy harvesting roller for a cargo handling system may comprise a shaft and a sleeve located on the shaft. A piezoelectric member may be coupled to the sleeve. A shell may be located radially outward of the piezoelectric member and configured to rotate relative to the sleeve. A radially inward surface of the shell may define at least one of a plurality of grooves or a plurality of protrusions.

CROSS REFERERENCE TO RELATED APPLICATIONS

This application claims priority to, and the benefit of, India Patent Application No. 201941041265 filed on Oct. 11, 2019 and entitled “ENERGY HARVESTING ROLLER ASSEMBLY,” which is hereby incorporated by reference in its entirety.

FIELD

The present disclosure relates generally to cargo management systems, and more specifically, to an energy harvesting roller.

BACKGROUND

Cargo handling systems, such as those used by aircraft for transport of containerized cargo or pallets, also referred to as unit load devices (ULDs), typically include roller trays containing transport rollers positioned along a cargo bay floor to facilitate movement of the ULDs relative to the bay floor. The power demands of cargo handling systems and aircrafts in general are increasing due to, for example, the use of smart electric systems and an increased number of active sensors, which draw power throughout a flight cycle. Conventional power generation may add more weight to the system which may reduce the systems performance and efficiency.

SUMMARY

An energy harvesting roller for a cargo handling system is disclosed herein. In accordance with various embodiments, the energy harvesting roller may comprise a shaft, a sleeve located on the shaft, a piezoelectric member coupled to the sleeve, and a shell located radially outward of the piezoelectric member and configured to rotate relative to the sleeve. A radially inward surface of the shell may define at least one of a plurality of grooves or a plurality protrusions.

In various embodiments, a wire may be electrically coupled to the piezoelectric member. In various embodiments, the wire may extend through a channel defined by the shaft. In various embodiments, a bearing may be located between the shaft and the shell, and a bushing may be located between the shaft and the bearing.

In various embodiments, the sleeve may comprise an electrically insulating material. In various embodiments, the piezoelectric member may be configured to vibrate in response to the shell rotating about the shaft. In various embodiments, a printed circuit board may be located radially inward of the shell and electrically coupled to the piezoelectric member.

An energy harvesting system for a cargo handling system is also disclosed herein. In accordance with various embodiments, the energy harvesting system may comprise a roller including a piezoelectric member configured to vibrate in response to rotation of the roller, a first energy storage device electrically coupled to the piezoelectric member, a controller in communication with the first energy storage device, and a tangible, non-transitory memory configured to communicate with the controller. The tangible, non-transitory memory may have instructions stored thereon that, in response to execution by the controller, cause the controller to perform operations, which may comprise: determining, by the controller, if a charge of the first energy storage device is greater than or equal to a first threshold charge; and directing, by the controller, power from the first energy storage device to a first application if the charge of the first energy storage device is greater than or equal to the first threshold charge.

In various embodiments, an energy conversion module may be electrically coupled between the piezoelectric member and the first energy storage device.

In various embodiments, the operations may further comprise: determining, by the controller, if the charge of the first energy storage device is greater than or equal to a second threshold charge, the second threshold charge being greater than the first threshold charge; and directing, by the controller, power from the first energy storage device to a second application if the charge of the first energy storage device is greater than or equal to the second threshold charge.

In various embodiments, the operations may further comprise: determining, by the controller, if the charge of the first energy storage device is greater than or equal to a third threshold charge, the third threshold charge being greater than the second threshold charge; and directing, by the controller, power from the first energy storage device to a third application if the charge of the first energy storage device is greater than or equal to the third threshold charge.

In various embodiments, the third application may comprise a second energy storage device. In various embodiments, the roller may further comprise a shaft, a sleeve located on the shaft, and a shell located radially outward of the piezoelectric member and configured to rotate relative to the sleeve. The piezoelectric member may be coupled to the sleeve. A radially inward surface of the shell may define at least one of a plurality of grooves or a plurality protrusions.

In various embodiments, a wire may be electrically coupled to the piezoelectric member. The wire may extend through a channel defined by the shaft. In various embodiments, a printed circuit board may be located radially inward of the shell. The printed circuit board may include the controller.

In various embodiments, the energy harvesting system may further comprise a roller tray. The roller may be located between a first vertical wall and a second vertical wall of the roller tray. A printed circuit board may be coupled to the roller tray. The printed circuit board may include the controller.

A roller tray is also disclosed herein. In accordance with various embodiments, the roller tray may comprise a first vertical wall, a second vertical wall, and a first energy harvesting roller located between the first vertical wall and the second vertical wall. The first energy harvesting roller may comprise a shaft, a sleeve located on the shaft, a piezoelectric member coupled to the sleeve, and a shell located radially outward of the piezoelectric member and configured to rotate relative to the sleeve. A radially inward surface of the shell may define at least one of a plurality of grooves or a plurality protrusions. An energy storage device may be electrically coupled to the first energy harvesting roller.

In various embodiments, a second energy harvesting roller may be electrically coupled to the energy storage device. In various embodiments, a controller may be in communication with the energy storage device, and a tangible, non-transitory memory may be configured to communicate with the controller. The tangible, non-transitory memory may have instructions stored thereon that, in response to execution by the controller, cause the controller to perform operations, which may comprise: determining, by the controller, if a charge of the energy storage device is greater than or equal to a first threshold charge; and directing, by the controller, power from the energy storage device to a first application if the charge of the energy storage device is greater than or equal to the first threshold charge.

In various embodiments, the operations may further comprise: determining, by the controller, if the charge of the energy storage device is greater than or equal to a second threshold charge, the second threshold charge being greater than the first threshold charge; and directing, by the controller, power from the energy storage device to a second application if the charge of the energy storage device is greater than or equal to the second threshold charge.

DETAILED DESCRIPTION OF THE DRAWINGS

Throughout the present disclosure, like reference numbers denote like elements. Accordingly, elements with like element numbering may be shown in the figures, but may not necessarily be repeated herein for the sake of clarity.

A first component that is “radially outward” of a second component means that the first component is positioned at a greater distance away from a common axis of the first and second components as compared to the second component. A first component that is “radially inward” of a second component means that the first component is positioned closer to a common axis of the first and second components as compared to the second component.

An energy harvesting roller, as disclosed herein, may include piezoelectric material. In accordance with various embodiments, the piezoelectric material is configured to vibrate in response to rotation of the roller shell. In this regard, as cargo is translated over the roller, the shell will rotate and the piezoelectric material will develop vibration energy. In various embodiments, the vibration energy may be converted into electrical energy and stored in a storage device (e.g., a supercapacitor). The energy generated by the roller may be provided to components (e.g., sensors, lights, energy storage devices, etc.) of the cargo handling system and/or of the aircraft. The energy harvesting roller may thus provide a supplementary power source for the cargo handling system and/or for the aircraft.

With reference toFIG.1, an aircraft90is illustrated having a cargo compartment92. A cargo door94provides access to cargo compartment92from outside aircraft90. In various embodiments, cargo compartment92may be equipped with one or more power drive units (PDUs)96configured to propel cargo and/or ULDs across cargo compartment92. Cargo compartment92may include one or more ball mats98having a plurality of freely rotating conveyance balls. Cargo compartment92further includes one or more roller trays100extending longitudinally along a length of cargo compartment92.

With reference toFIG.2, a roller tray100is illustrated. Roller tray100includes a pair of vertical walls, including first vertical wall102and second vertical wall104. First and second vertical walls102,104extend from a floor105of roller tray. In various embodiments, first and second vertical walls102,104and floor105may be part of a single extrusion profile. In accordance with various embodiments, roller tray100further includes one or more energy harvesting rollers110(referred to herein as rollers110). Rollers110are located between and may be coupled to first vertical wall102and second vertical wall104. Roller110are configured to roll or spin in response to cargo and/or ULDs translating over roller tray100. In this regard, conveyance of cargo over roller tray100causes rollers110to spin.

With reference toFIG.3, a roller110is illustrated. In accordance with various embodiments, roller includes a shell112and a shaft114. Shell112may rotate relative to shaft114. Shaft114may be coupled to first and second vertical walls102,104, with momentary reference toFIG.2. A pair of bearings116may be located between shell112and shaft114. Bearing116may facilitate rotation of shell112relative to shaft114. A wire118may be located through shaft114.

Referring toFIGS.4A and4B, roller110is illustrated with shell112removed to illustrate internal features of roller110. Roller110includes one or more piezoelectric member(s)120. Piezoelectric members120are formed of a piezoelectric material such as lead zirconate titanate, barium titanate, lithium niobate, quartz, or any other suitable piezoelectric material. In various embodiments, piezoelectric members120comprise each comprise a piezoelectric bimorph having a passive layer between two active layers of piezoelectric material.

Roller110further includes a sleeve122and pair of bushings124. InFIG.4Bone of the bushings124and one of the bearings116have been removed to illustrate better illustrate wire118. Sleeve122may be located over and around shaft114. Bushings124may be located at the axial ends of sleeve122Bushing124may be located radially between shaft114and bearings116.

In accordance with various embodiments, wire118is in direct contact with each of the piezoelectric members120. In this regard, wire118is electrically coupled to each of the piezoelectric members120. In various embodiments, wire118may be routed through shaft114. Stated differently, wire118may be located in a channel130defined by shaft114.

With reference toFIG.5, an axial end134of shaft114is illustrated. In accordance with various embodiments, an inlet132of channel130may be formed in axial end134of shaft114, and one or more outlet(s)136of channel130may be formed in the outer circumferential surface138of shaft114. The number of outlets136may correspond to (i.e., be equal to) the number of piezoelectric members120.

In accordance with various embodiments, sleeve122defines one or more sleeve grooves140. Sleeve grooves140are configured to receive piezoelectric members120. The number of sleeve grooves140may correspond to (i.e., be equal to) the number of piezoelectric members120. Sleeve122comprises an electrically insulating material. For example, sleeve122may be formed of rubber, polyvinyl chloride, polypropylene, or other suitable electrically insulating material.

With reference toFIG.6, shell112is illustrated. In accordance with various embodiments, shell112includes a radially outward surface142and a radially inward surface144. Radially inward surface144is oriented away from (i.e., opposite) radially outward surface142and towards the axis of rotation of roller110. In various embodiments, shell112may comprise a metal or metal alloy. In various embodiments, shell112may be aluminum or an aluminum alloy. Radially inward surface144defines a plurality of grooves146. In various embodiments, the number of grooves146may be equal to or greater than the number of piezoelectric members120, with momentary reference toFIG.4A.

Referring toFIG.7A, in accordance with various embodiments, rotation of shell112about sleeve122is configured to generate vibrational energy in piezoelectric members120. For example, as shell112rotates in direction150, piezoelectric member120, which is located in groove146, deflects from a neutral position152to a second position154. As shell112continues to rotate in direction150, piezoelectric member120translates out groove146. The piezoelectric member120may then vibrate freely between second position154and a third position156. Piezoelectric member120may continue to vibrate until the next groove146ais located radially outward of piezoelectric member120, at which point, groove146amay receive piezoelectric member120. Piezoelectric member120rotates with groove146auntil piezoelectric member120deflects to second position154, at which point, piezoelectric member120translates out groove146aand vibrates freely until the next groove146is located radially outward of piezoelectric member120. In this regard, as shell112rotates, piezoelectric member120will be received by the next groove146and piezoelectric member120will vibrate between second position154and third position156each time piezoelectric member120exits a groove146. For example, during a cargo loading or unloading, shell112rotates in response to a ULD translating over roller110, thereby causing piezoelectric member120to vibrate and generate vibrational energy. As described in further detail below, the vibrational energy generated in piezoelectric member120is converted into electrical energy and stored in a storage device, for example, a supercapacitor.

WhileFIGS.6and7Aillustrate radially inward surface144of shell112defining grooves146, it is further contemplated and understood that shell112may include any structure configured to cause vibration of piezoelectric members120. For example, and with reference toFIG.7B, in various embodiments, radially inward surface144may define one or more protrusions346. Protrusions346may extend radially inward from radially inward surface144of shell112. Protrusions346are configured to cause piezoelectric member120to vibrate between second position154and third position156in response to rotation of shell112about shaft114.

Referring toFIG.8A, and with continued reference toFIG.4B, an energy harvesting system200is illustrated. In accordance with various embodiments, energy harvesting system200includes an energy source202. Energy source202comprises one or more rollers110including piezoelectric members120. Energy harvesting system200further includes an energy conversion module204. Energy conversion module204converts the vibration energy from piezoelectric member120to electrical energy. Energy conversion module204may include a rectifier206and a voltage regulator208. Rectifier206comprises an alternating current (AC) to direct current (DC) converter, for example, an AC to DC bridge rectifier. Rectifier206is electrically coupled to piezoelectric members120(e.g., via wire118). Rectifier206may convert the energy (e.g., AC) received from piezoelectric members120to DC. Voltage regulator208may be electrically coupled to an output of rectifier206.

Energy harvesting system200further includes an energy storage module210. Energy storage module210is configured to temporarily store the electrical energy generated by energy source202. Energy storage module210may comprise a storage device212. Storage device212comprises a rechargeable battery. In various embodiments, storage device212comprises a supercapacitor (e.g., an electrostatic double layer capacitor, hybrid capacitor, etc.). Storage device212is configured to store the energy generated by energy source202and output from energy conversion module204. Energy storage module210further includes a controller214electrically coupled to an output of storage device212. Controller214may be configured to control the storage and disbursement of energy generated by rollers110.

Controller214may comprise a processor and a tangible, non-transitory memory216. The processor can be 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 a combination thereof. As used herein, the term “non-transitory” is to be understood to remove only propagating transitory signals per se from the claim scope and does not relinquish rights to all standard computer-readable media that are not only propagating transitory signals per se. Stated another way, the meaning of the term “non-transitory computer-readable medium” and “non-transitory computer-readable storage medium” should be construed to exclude only those types of transitory computer-readable media which were found in In re Nuijten to fall outside the scope of patentable subject matter under 35 U.S.C. § 101.

Controller214may comprise one or more logic modules that implement energy harvesting and disbursement logic. An energy utilization phase220of energy harvesting system200includes one or more applications222electrically coupled to controller214. Controller214is configured to output energy (e.g., voltage) stored in storage device212to applications222.

In various embodiments, one or more over voltage protection, over current protection, and/or reverse voltage protection circuits may be located between controller214and applications222. In various embodiments, energy conversion module204and energy storage module210and/or circuitry for applications222may be located on a printed circuit board (PCB)224. PCB224may be located within in roller110. For example, PCB224may be located radially inward of shell112. In various embodiments, PCB224may be located on or within roller tray100, with momentary reference toFIG.2. In various embodiments, PCB224may be mounted to first vertical wall102. Mounting PCB224to roller tray100may allow multiple to rollers110to be connect to a single PCB224and/or to a single storage device212. With reference toFIG.9, an exemplary circuit250, which may be included on PCB224, is illustrated, in accordance with various embodiments. Piezoelectric members120are electrically coupled to an input of circuit250. Circuit250may include storage device212and circuitry for energy conversion module204. Circuit250may further include application circuitry252. In various embodiments, application circuitry252may include wireless sensor circuits coupled to a wireless transmitter256. In this regard, energy harvesting system200may be employed to power wireless communication for an autonomous cargo handling system. In various embodiments, the output of application circuitry252may be a wired connection. In various embodiments, one or more over voltage protection, over current protection, and/or reverse voltage protection circuits254may be located between controller214and application circuitry252. In various embodiments, application circuitry252may not be located on PCB224. For example, an output of circuit250and PCB224may be electrically coupled to an input of application circuitry located off PCB224.

With reference toFIG.8B, exemplary energy distribution logic, which may be applied by controller214, is illustrated, in accordance with various embodiments. In accordance with various embodiments, controller214determines where to distribute energy (e.g., output voltage) based on energy (e.g., charge) within storage device212. At time T1, controller214determines the charge C of storage device212. If controller214determines charge C is greater than or equal to a first threshold charge, controller214directs power232from storage device212to a first application234. In various embodiments, first application234may be a health monitoring circuit and sensors. At time T1controller214may also determine if charge C is greater than a second threshold charge. The second threshold charge may be the sum of the voltage associated with powering first application234and the voltage associated with powering a second application238. If controller214determines charge C is greater than or equal to the second threshold charge, controller214directs power236from storage device212to second application238and power232to first application234. If controller214determines charge C is less than the second threshold charge, controller214only directs power232to first application234and sets the next time controller214will determine the charge of storage device212to time T2.

The power generated by roller110may be greater than the power supplied to first application234and the charge of storage device212may increase. Controller214may be configured to determine at time T2if the charge C of storage device212is greater than or equal to the second threshold charge and less than a third threshold charge. If controller214determines charge C is greater than or equal to the second threshold charge and less than the third threshold charge, controller214directs power236from storage device212to second application238. In various embodiments, second application238may be illumination of lights in the cargo deck.

As roller110continues to spin, the power generated by piezoelectric members120may be greater than the power supplied to first and second applications234,238and the charge of storage device212may increase. Controller214may be configured to determine at time T3if the charge C of storage device212is greater than or equal to the third threshold charge. If controller214determines charge C is greater than or equal to the third threshold charge, controller214directs power240from storage device212to a third application242. The third threshold charge may be the sum of the voltage associated with powering first application234, second application238, and third application242. In various embodiments, third application242is a power storage device (e.g., a supplementary power source). In this regard, energy generated by roller110may be provided to other cargo handling and/or aircraft power sources. In accordance with various embodiments, the priority of first application234, second application238, and third application242can be interchangeable. For example, controller214may be configured to provide power to third application242prior to first application234and/or second application238.

Energy harvesting system200may provide supplementary power for the cargo handling system. Energy harvesting system200may be employed to power various cargo handling and/or aircraft sensors, such as proximity sensors, smoke sensor, automatic latch sensors, water ingress sensors, etc. Energy harvesting system200may be employed to power visual indicators and lights of the cargo handling system. Excess power generated by energy harvesting system200may be stored and/or used to replenish other aircraft power source. Energy harvesting system200tends to reduce the amount power consumed from other the aircraft power sources, which may allow the size and capacity of the other aircraft power sources to be reduced.

Benefits, other advantages, and solutions to problems have been described herein with regard to specific embodiments. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in a practical system. However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of the disclosure. The scope of the disclosure is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” It is to be understood that unless specifically stated otherwise, references to “a,” “an,” and/or “the” may include one or more than one and that reference to an item in the singular may also include the item in the plural. All ranges and ratio limits disclosed herein may be combined.

Moreover, where a phrase similar to “at least one of A, B, or C” is used in the claims, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B and C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C. Elements and steps in the figures are illustrated for simplicity and clarity and have not necessarily been rendered according to any particular sequence. For example, steps that may be performed concurrently or in different order are illustrated in the figures to help to improve understanding of embodiments of the present disclosure.