Patent Description:
Battery-powered devices are limited by the duration of their battery charge. Rechargeable batteries extend the usable life of device, but in order to take advantage, the battery should be charged conveniently with minimal interference with the function of the device.

Moreover, as battery-powered drones become more prevalent, they are being employed in various aerial applications such as data gathering, still photography, and video recording. Recreationally, for example, drones are commonly seen recording all-day events like weddings, sporting events, or holiday celebrations. Current drones powered by rechargeable batteries need to visit a charging station to be manually connected to a power source for their batteries to be recharged. A battery charging system according to the preamble of claim <NUM> is described in <CIT>.

In at least a preferred embodiment, the present invention is directed to a charging system, comprising: at least one motor; conductive charging arms rotatably coupled to the at least one motor; a controller operably coupled to the at least one motor and configured to control the at least one motor to rotate the conductive charging arms; and a sensor operably coupled to the controller and configured to sense presence of a powered device and provide a signal to notify the controller of the presence of the powered device; wherein, in response to receiving the signal notifying of the presence of the powered device, the controller controls the at least one motor to rotate the conductive arms to positions of electrical charging contact with the powered device.

In at least one further embodiment of the charging system, the powered device is a drone powered by a rechargeable battery; and the positions of electrical charging contact include electrical connections to terminals of the rechargeable battery. In addition, the charging system may also incorporate the feature of the at least one motor including a respective stepper motor operably coupled to each of the conductive arms.

In another embodiment, the present invention is directed to a charging system, comprising: first and second motors; first and second conductive charging arms rotatably coupled to the first and second motors, respectively; a controller operably coupled to the first and second motors and configured to control the first and second motors to rotate the first and second conductive charging arms, respectively; and a sensor operably coupled to the controller and configured to sense presence of a powered device and provide a signal to notify the controller of the presence of the powered device; circuitry arranged to provide electrical charging power from the first and second conductive arms to respective terminals of a rechargeable battery of the powered device; and first and second conductive attachments configured to be attached to the powered device; wherein, in response to receiving the signal notifying of the presence of the powered device, the controller controls the first and second motors to rotate the first and second conductive arms to positions of electrical contact with the first and second conductive attachments, respectively; and wherein the circuitry is arranged to electrically connect the first and second conductive attachments to respective terminals of the rechargeable battery of the powered device. In at least one variation of this embodiment, the powered device is a drone.

The present invention is illustrated in the accompanying drawings, wherein:.

With the intent to enable long durations of drone charging through automation, embodiments of the charging system described herein will enable users to deploy the system in an array of environments with whatever the expressed interest a user may have to utilize the system. Benefits of various designs include the need for only low precision in drone landing position and orientation, minimal drone modification allowing for arbitrary drone vehicle charging with the same charging device, and a minimal landing surface. In fact, only a flat patch of terrain is sufficient for locating the charger in one or more embodiments.

<FIG> illustrates a charging system <NUM> having two conductive arms <NUM>, <NUM>, for example rods, that are positioned to make electrical contact with corresponding contacts on a drone <NUM> that moves into position to be recharged. Charging arms <NUM>, <NUM> are connected to charging rod motors <NUM>, <NUM> respectively so as to rotate or swing together/apart about corresponding pivots depending on the size and position of the drone <NUM>. The general design of the charging system <NUM> entails a variety of choices for the arms, arm actuation, and onboard controller for the system.

In at least a first embodiment of the present invention, the charging system <NUM> may further include an input power source <NUM> coupled to a battery charger/controller <NUM>. Input power source <NUM> may be line power, a battery, fuel cell, solar panel, or other power source without limitation. The configuration of drone <NUM> is not limited except to the extent that it has a rechargeable battery <NUM> with charging terminals to connect to the charging system <NUM>. Charging system <NUM> may further include a polarity matching circuit <NUM>, which routes the positive and negative voltages from charging arms <NUM>, <NUM> to match the proper terminals on battery <NUM>. This ensures that no matter the orientation of the landing, a positive node and a negative node may make contact and ensure a charge is delivered to the drone. In this first embodiment, the polarity matching circuit is incorporated into the drone <NUM>.

<FIG> further illustrates charging boots <NUM>, <NUM> which operate as the terminals for the rechargeable battery <NUM> that connect to the charging system <NUM>. In one or more embodiments, charging boots <NUM>, <NUM> are configured to be attached to appropriate locations on drone <NUM> so as to be accessible to the conductive arms <NUM>, <NUM> without the conductive arms interfering with or damaging any other part of the drone <NUM>. Further, the charging boots <NUM>, <NUM> are positioned such that, when the drone is in place in front of the charging system <NUM>, the conductive arms <NUM>, <NUM> are rotated into contact with the charging boots <NUM>, <NUM>, respectively. The presence of the drone <NUM> is detected via a sensor <NUM> connected to the charger/controller <NUM>. When the sensor <NUM> detects the presence of the drone <NUM>, the charger/controller <NUM> activates the motors <NUM>,<NUM> such that the conductive arms <NUM>, <NUM> are rotated via the motors <NUM>, <NUM>, respectively, which are connected to the conductive arms. The motors <NUM>, <NUM> are controlled by a charger/controller <NUM> so as to rotatively move the conductive arms <NUM>,<NUM> to contact the charging boots <NUM>,<NUM>. In at least one embodiment, when electrical contact between the conductive arms <NUM>,<NUM> and the charging boots <NUM>,<NUM> is made, the charger/controller <NUM> detects the electrical contact and can begin charging power from input source <NUM> to the drone battery <NUM>. In this first embodiment, the power inputted through the charging boots <NUM>,<NUM> is fed through the polarity matching circuit <NUM> in the drone <NUM>. The polarity matching circuit <NUM> detects the polarity of the voltages inputted into it from the respective conductive arms <NUM>,<NUM>, and configures its outputs (i.e., via a switching circuit) to match the polarities of the inputted voltages to the corresponding terminals of the rechargeable battery <NUM>, thereby charging the battery.

<FIG> is a top view schematically showing the operation of a drone <NUM> proximate to charging station <NUM>. For example, drone <NUM> may land near charging station <NUM>. In the illustrated example, conductive arms <NUM>, <NUM> are rotatably mounted to a base unit <NUM> that may incorporate the motors <NUM>, <NUM> controlled by an onboard system in charger/controller <NUM> to help drive operation of charging system <NUM>. There are a variety of ways which this may be achieved. In one or more examples, a Raspberry Pi device or other processor circuit is used to act as an onboard computer regulating actions for swinging charging arms <NUM>, <NUM>, detecting drone <NUM>, and processing / sharing data collected from drone <NUM> at the end of each flight. The case of base station <NUM> may be light yet durable, enabling it to be deployed in a wide range of environments. In one or more embodiments, some form of detection be used in determining whether the drone has arrived. For example, as shown in <FIG>, the sensor <NUM> operatively connected to the charger/controller <NUM> through the base unit <NUM> may be used to determine whether or not drone <NUM> has approached the charging station <NUM>. There are a variety of detection techniques that may be employed, including a motion sensor, direct communication with the drone <NUM> (i.e., the drone communicates that it has landed in the target area and charging system <NUM> takes over swinging charging arms <NUM>, <NUM>), an optical beam detector (i.e., the drone <NUM> interrupts or reflects an optical beam emitted by the detector), or other detection devices similar to those used to detect the presence or motion of moving objects in other applications.

The charging system <NUM> may be configured to work with many, most, or all drones if appropriately modified or configured to incorporate at least a rechargeable battery circuit with charging boots <NUM>,<NUM> that correctly positioned to align with the charging system <NUM>. Example modifications may include clamping charging boots <NUM>, <NUM> on the drone legs (for example, where conductive arms <NUM>, <NUM> contact with the drone legs). On the charger side, the heights of the charging arms <NUM>,<NUM> may be adjustable to match the charging boot height. In one or more embodiments, charging boots <NUM>, <NUM> may be attached to the drone at the height of conductive arms <NUM>, <NUM>, in which case all drones provided with the charging boots at the same height can all be charged by the same charging station.

Charging boots <NUM>, <NUM> may be applied to the legs of drone <NUM> as they are commonly structural vertical components of the drone, although other locations suitable to the positioning and motion of charging arms <NUM>, <NUM> and structure of drone <NUM> are contemplated. For example, a small pole (not shown) that stands up above drone <NUM> with charging boots <NUM>, <NUM> built into it could be arranged to make the same electrical contact with charging arms <NUM>, <NUM> as though charging boots <NUM>, <NUM> were attached to the drone legs. Such an arrangement might be particularly advantageous in instances where the user might not be able to easily clamp charging boots <NUM>, <NUM> on the legs.

In another example, charging boots <NUM>, <NUM> could be more invasively attached such as with screws or nuts/bolts, instead of or in addition to clamps. but clamp-on charging boots avoid the need to drill into the drone body and charging boots <NUM>, <NUM>. Another option is replacement drone legs having charging boots <NUM>, <NUM> already attached, but such replacement legs might need to be customized to the drone <NUM>, whereas clamp-on charging boots might have greater universality. Regardless of the charging boot scheme, the drone <NUM> will need an electrical connection to be made between the battery connections on drone <NUM> and charging boots <NUM>, <NUM> to route charging voltage to the battery <NUM> from the charging system <NUM>.

In one or more embodiments, and without limitation, charging arms <NUM>, <NUM> may be constructed of carbon fiber, graphite, or metal tubing, or with a non-conductive material provided with an electrically conductive material such as by plating or wiring (external or internal) connected to appropriate contacts at either end of charging arms <NUM>, <NUM>. By way of nonlimiting example, electrical conduction through charging arms <NUM>, <NUM> may be accomplished either through the graphite or metal if used as the rod material, or through a gold coating on the rod to minimize corrosion of electrical contacts. Charging arm actuation may be through one or more electrical motors such as a DC or stepper motor driving charging arms <NUM>, <NUM> directly or through a gearbox to match the motor speed to the desired arm swinging speed.

Additionally or alternatively, the charging station <NUM> may be controlled remotely. Example implementations may involve connecting the charging station <NUM> to an internet network either with a direct internet connection or through wifi, enabling remote control, operation, and monitoring.

In one or more embodiments, the drone <NUM> may have an augmentation applied to it enabling the conductive arms <NUM>, <NUM> to better interface with the battery <NUM>. By way of nonlimiting example, attached to each of the drones landing legs may be a conductive coupling with a v-cut groove matching the depth of the charging arms.

One or more constituent components of the charging station <NUM> may be contained within a suitable housing. In one or more embodiments, battery charger <NUM>, charging rod motors <NUM>, <NUM>, and related electrical and mechanical couplings between them and between charging rod motors <NUM>, <NUM> and charging arms <NUM>, <NUM> may be housed in an acrylic casing. Charging arms <NUM>, <NUM> may be provided with a conductive adhesive to carry out the charge. In one or more embodiments, power may be inputted to the charging station <NUM> via USB connection. The input power may be provided by one or more of line power, batteries, fuel cells, or solar panels. To conserve power, the charging station <NUM> may be configured with a sleep mode, in which the charging station <NUM> powers down or off after a predetermined time of inactivity. The charging station <NUM> may be awakened from its sleep mode by a signal from the drone <NUM> or upon sensing the drone <NUM>, for example.

In one or more embodiments, the charging station <NUM> may be provided with a platform that is easily broken down and transported to a new site. For even greater portability, a small motor/controller box and detachable charging arms may be used.

In one or more embodiments, the charging station <NUM> may include data uplink hardware controlled by the charger/controller <NUM>. Data, including but not limited to environmental conditions, photographic data, video data, or audio data may be retrieved from drone <NUM> and transmitted via wifi or Bluetooth for example. With this capability, charging station <NUM> enables long-ranged data collection over extended intervals of time. For example, a user can simply deploy the charging station <NUM>, collect the aerial data that is needed, and pack up from the site, potentially reducing or eliminating labor costs associated with, e.g., a pilot, a drone technician, and other staff that may be required to charge the drone and redeploy it back into the field.

<FIG> illustrate examples of the disclosed battery charging system, including examples suitable for charging a battery-powered drone, although other applications are contemplated. Specifically, <FIG> shows a side view of the base unit <NUM> and charging arms <NUM>,<NUM> of the charging system <NUM>, while <FIG> shows a top view of the base unit <NUM> and charging arms <NUM>,<NUM>, and <FIG> shows a general top view of an example implementation of the interior circuitry of the base unit <NUM> of the charging system <NUM>.

<FIG> shows a first front perspective view of a drone <NUM> proximate to the base unit <NUM> of the charging station <NUM> in an example operation. <FIG> shows a second front perspective view of the drone <NUM> proximate to the base unit <NUM> of the charging station <NUM> in operation. <FIG> shows a side perspective view of a drone <NUM> proximate to the base unit <NUM> of the charging station <NUM>. Lastly, <FIG> shows a front perspective view of an example of the interior circuitry of the base unit <NUM> of the charging station <NUM> in operation according to the present invention.

Claim 1:
A charging system (<NUM>), comprising:
two motors (<NUM>, <NUM>);
two arms each rotatably (<NUM>, <NUM>) coupled to the motors (<NUM>, <NUM>) respectively;
a controller (<NUM>) operably coupled to the motors (<NUM>, <NUM>) and configured to control the motors (<NUM>, <NUM>) respectively to rotate said arms (<NUM>, <NUM>); and
a sensor (<NUM>) operably coupled to the controller (<NUM>) and configured to sense presence of a powered device (<NUM>) and provide a signal to notify the controller (<NUM>) of the presence of the powered device (<NUM>);
wherein, in response to receiving the signal notifying of the presence of the powered device (<NUM>), the controller (<NUM>) controls the at least one motor (<NUM>, <NUM>) to rotate the arms (<NUM>, <NUM>) to positions of electrical charging contact depending on the size and position of the powered device (<NUM>),
characterized in that
said rotatably arms (<NUM>, <NUM>) are conductive charging arms,
wherein the powered device (<NUM>) is a drone powered by a rechargeable battery (<NUM>); and
wherein the positions of electrical charging contact include electrical connections to terminals of the rechargeable battery (<NUM>).