RELATED APPLICATION

The present application claims the benefit of U.S. Provisional Application No. 61/558,290 filed November 10, 2011, which is incorporated herein by reference. TECHNICAL FIELD

The present invention relates to surveillance robots. More particularly, it relates to cutting device accessories for surveillance robots.

BACKGROUND OF THE INVENTION

During combat and other situations when an adversary may be encountered, obtaining visual surveillance of the surrounding environment can be beneficial. Gaining an appropriate visual vantage point, however, often places individuals and equipment in harm's way. For example, peering through a doorway to look into an adjacent room can expose an individual to hostile fire. Personnel ascending and descending stairwells and entering attic spaces may be similarly exposed to hidden or unexpected dangers. Outdoor environments can provide similar obstacles to visual surveillance which, when circumnavigated or avoided, may expose an individual to hostile fire. Such obstacles may include, for example, walls, fences, berms, buildings, rock formations, and the like.

The use of robotic surveillance systems is becoming increasingly common in hostile environments. The robots used in these surveillance systems are utilized to provide visual images. After delivery into an area to be surveilled, such as by throwing, the robots can be remotely maneuvered with an operator control unit to position the robot and operate an embedded camera as desired by a user.

In certain environments, it may be desirable to have robotic surveillance systems interact with features of the environment. For example, wires or strings laid along the ground where the robot is traveling may need be cut or severed for any number of strategic, safety, or operational reasons.

SUMMARY OF THE INVENTION

The device of the present application substantially meets the aforementioned needs of the industry. Embodiments of the device attach to a robot and allow an operator to remotely cut wires or strings laid along the ground. In an embodiment, the robot operates by dragging a hook behind it to catch wires or strings. The hook forms the lower jaw of a wire cutter, which pivots on a cutter housing fixed on the end of an extension or tail off the back of the robot. The upper jaw is fixed to this cutter housing adjacent to the lower jaw, allowing a shearing action when the lower jaw is closed upon the upper jaw. The jaws may also be configured for a cleaving action wherein the jaws contact directly along the cutting surface, rather than sliding past each other.

When a wire is caught by the dragging hook, the wire contacts a switch at the opening of the jaws. This switch can be used to activate an electrical circuit to automatically close the jaws of the cutter, thereby severing the caught wire. The switch can also be connected to the robot's internal electronics and then used to provide feedback to a remote operator or used in a more complex automatic behavior. If provided to a remote operator, the operator may choose to remotely activate the jaws in order to sever the wire. During operation where no cutting or catching is desired, the lower jaw may be closed to prevent the unwanted catching of environmental objects.

In another feature and advantage of embodiments of the invention, because considerable force is required to sever the wire (approximately 300N for a 16AWG copper wire with moderately sharp blades in a shearing configuration), and because the device is intended to be compact in order to fit on a miniature robot, significant mechanical advantage is required to allow small actuators to successfully drive the lower jaw closed. This mechanical advantage is provided by a gearbox powered by a small motor. In this way, a small motor with an appropriately sized gearbox can be used to drive the mechanism, though obtaining this high torque with a small motor results in low actuation speed. In another feature and advantage of embodiments of the invention, the cutting surfaces of embodiments are shaped such that the wire is drawn as close as possible to the lower jaw's pivot point, thereby minimizing the torque necessary to drive the jaw.

In another feature and advantage of embodiments of the invention, all high forces are contained within the cutter housing, allowing the remainder of the robot parts to be sized appropriately for other forces, rather than requiring them to tolerate high loads.

In an embodiment, the switch and motor are connected to electronics internal to the robot, which provide power and, if a sensing configuration is used (rather than simply using an activated switch to directly power the motors), an interface for the switch input to allow the robot to sense the presence of a wire.

Certain applications, such as those employing a robot with the capability to operate either in a normal orientation or inverted orientation (i.e. upside-down), can benefit from the use of a device capable of cutting in either configuration. In embodiments, the device housing is extended upward and a complementary jaw is added in the same manner as the lower jaw, in this new space. In embodiments, the complementary jaw can be driven by the same worm as the lower jaw. Because only one jaw would be engaged with a wire at any time, this places no additional force requirements on the mechanism. In another embodiment, force transfer in the form of a system of levers is provided.

A first lever inverts the motion of a pull cable (turning a pulling action into a pushing action), while a second lever is rigidly coupled to the lower jaw, and connected to the first lever by a follower link. To keep the system compact and to keep components off of the ground, the force input to the lower jaw can be above its pivot point; it can also extend away from the robot in order to close the jaws. The above-described system of levers allows this to be done with a cable, which is advantageous over a push rod in that it cannot buckle under the system's load. Thus, only the robot's tail must be designed to take compressive loading, rather than both the tail and the actuating piece, allowing the system to be more compact. Additionally, such an embodiment enables the lower jaw to enter a default position when the device is powered off with the inclusion of a return spring, which is safer for handling.

A feature and advantage of embodiments of the invention is that a user can maintain a safe standoff distance from a suspect wire. Further, the user can remotely eliminate any threat the suspect wire may pose by cutting it. Another feature and advantage of embodiments of the invention is that wires can be cut selectively. Because the wire cutter can be user-controlled and the user can view multiple at-issue wires using the visual images provided by the robot, wires can be subsequently distinguished and selectively cut.

The above summary of the invention is not intended to describe each illustrated embodiment or every implementation of the present invention. The figures and the detailed description that follow more particularly exemplify these embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention, in connection with the accompanying drawings, in which: FIG. 1 A is a perspective view of a robot device according to an embodiment of the present invention.

FIG. IB is a side view of the robot device of FIG. 1A.

FIG. 2 is a side view of a robot device with a wire cutter engaged with a wire, according to an embodiment. FIG. 3 is a cross sectional view of the wire cutter of FIG. 2.

FIG. 4 is a side view of a robot device with a wire cutter having a closed jaw, according to an embodiment.

FIG 5A is a view of a connector including a connecting flange and an electrical connector for connecting a tail to a robot device body according to an embodiment of the present invention.

FIG. 5B is a rear elevational view of a connector portion of a robot body according to an embodiment of the present invention..

While the invention is amenable to various modifications and alternative forms, specifics thereof have by shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE DRAWINGS Referring to FIGS. 1A-4, a robot device 201 having a cutter-coupleable tail interface is depicted according to an embodiment of the present invention. Robot 201 generally includes a body 203, a tail assembly 204, and one or more wheel assemblies 206. As depicted, robot 201 includes a generally elongated body 203, but can comprise any desirable body shape. Robot 201 includes two wheel assemblies 206 for locomotion, with individual wheel assemblies 206 positioned on opposite sides of body 203. Tail assembly 204 extends roughly intermediate body 203 so that body 203 can be stabilized and oriented. Body 203 can include a camera for remote surveillance, a power supply for powering robot and a communication system for receiving remote commands. Additional information regarding two-wheeled robots can be found in U.S. Patent Publication No. 2010/0152922, and U.S. Patent No. 7,559,385, each of which is incorporated herein by reference.

In some embodiments, tail assembly 204 can include a fastening mechanism, a tail extension, and a weight. The tail extension can be rigid or flexible such that the weight acts as a counterweight to the rotation of the robot vehicle body 203 when the wheel assemblies 206 rotate. Tail assembly 204 can attach to robot body 203 with any of a variety of mechanisms. In some embodiments, the tail can be fixed rigidly to the robot's body by screws or other fasteners. As shown in FIGS. 5 A and 5B in one aspect, the connector assembly 22 of the tail assembly 204 comprises a mount configured as a connecting flange 26, an electrical connector 28 and fasteners 30, such as screws. In this configuration, the robot body 203 can define a port 32 for receiving the flange 26 and an electrical connector 34 for cooperatively engaging the electrical connector 28 of the tail. The electrical connection providing power, control functions for the rear wheels and motors. Alternatively, the connector can provide power and control for other accessories in tail. Various tails can have similar mounts to selectively allow attachment to the robot body and the mounts are suitably usable in the field at points of surveillance. An embodiment of the invention is a kit with a plurality of selectively attachable tails with differing functions and or capabilities.

Tail 204 can also provide an interface for coupling any number of accessories. Various accessories and tail configurations that can be used with a robot device are disclosed in PCT Application NO. PCT/US 12/60902, which is hereby incorporated by reference. A robot device having a tail-mounted cutting accessory 202 according to an embodiment of the present invention is depicted generally in FIGS. 1 A-4.

A robot device 201 having a tail-mounted cutting accessory 202 is depicted. Cutting accessory 202 can be mounted on the tail of robot 201 and extend distally from the robot body. Cutting accessory 202 can generally include cutter housing 216, lower jaw 217, motor 218, dowel pin 219, worm 210, and upper jaw 213. Cutter housing 216 can form the housing or container for several of the components of cutting accessory 202. In one embodiment, cutter housing 216 houses motor 218, dowel pin 219, worm 210, and a portion of lower jaw 217. In other embodiments, some or all of the aforementioned components can be housed inside or outside of cutter housing 216. Cutter housing 216 can be fixed on the end of an extension or tail off the back of the robot. Cutting accessory 202 can therefore be coupled to any tail, including on existing robots or newly manufactured robots.

In one embodiment, lower jaw 217 is substantially C-shaped, thereby having a hook 224 as one of the ends of the C-shape that forms a cutting portion of lower jaw 217 of cutting accessory 202. The opposite end of the C-shape of lower jaw 217 comprises worm gear 211. Worm gear 211 is disposed on the outside of the C-shape and distal the hook end of lower jaw 217. Worm gear 211 comprises one or more teeth that are configured to interlock with the threads of worm 210 and generally comprise a portion of a full gear, or a sector gear. In an embodiment, worm gear 211 extend from the non-hook end of lower jaw 217 all the way to the opposite, hook end 224 of the jaw 217. In another embodiment, and as depicted in FIG. 3, worm gear 211 extend from the non-hook end of lower jaw 217 to a position intermediate the outside length of lower jaw 217, thereby forming a shorter sector gear. As depicted in FIG. 3, the portion of lower jaw 217 containing worm gear 211 can be contained within cutter housing 216, while the hook portion of lower jaw 217 extends outside of cutter housing 216. Lower jaw 217 further comprises an aperture 226 for receiving dowel pin 219. Lower jaw 217 aperture 226 is positioned intermediate the hook end 224 of lower jaw 217 and the non-hook, worm gear 211 end such that the hook portion 224 and worm gear 211 can rotate about dowel pin 219. As depicted in FIG. 3, worm 210 and the corresponding worm gear 211 form a traditional worm drive. As depicted, and as described above, worm 210 can be housed within cutter housing 216. Worm 210 can comprise a traditional single thread or single start worm, or, in another embodiment, can comprise one or more threads in a multiple thread or multiple start worm. Worm 210 and the corresponding worm gear 211 that forms a sector gear therefore provide a simple and compact way to achieve a high torque, low speed gear ratio for the action for the hook of lower jaw 217. Motor 218 can also be housed within cutter housing 216. Motor 218 can be any appropriately-sized motor or actuator configured to interface with worm 210. Motor 218 powers worm 210 at a low speed such that worm 210 is driven and thereby rotated.

Dowel pin 219 can extend from a secured portion outside of cutter housing 216 through the aperture of lower jaw 217, and is likewise secured to the opposite outside end of cutter housing. Thus, a portion of dowel pin 219 is housed within cutter housing 216 and portions remain outside. In embodiments, dowel pin 219 can be secured on the inside sides of cutter housing 216. Dowel pin 219 provides the axle about which lower jaw 217 rotates. Referring again to FIG. 2, cutting accessory 202 can further comprise switch assembly 212 connected to accessory with screws 222. Switch assembly 212 generally comprises switch lever 213 and control/communication wires 218. Switch lever 213 is disposed near the opening of lower jaw 217 and upper jaw 223 and connected to switch assembly 212. Switch lever 213 provides a sensing interface for the switch to allow robot 201 to sense the presence of a wire. Switch assembly 212 can comprise any electrical or mechanical component that can break the electrical circuit of motor 218 to power worm 210. Effectively, switch assembly 212 operates as a gate between power from robot 201 (or controller) to motor 218. Control/power wires 214 therefore provide power and control to motor 218 when activated by switch assembly 212. In an embodiment, switch assembly 212 can be configured to automatically close the jaws 217 and 223 of cutting accessory 202. In another embodiment, switch assembly 212 can be configured to be connected to the internal electronics of robot 201 and used to provide feedback to a remote operator or used in a more complex automatic behavior. In embodiments, an operator can remotely interface with switch assembly 212 to remotely activate the jaws 217 and 223. Referring to FIG. 4, upper jaw 223 can be fixed to cutter housing 216 adjacent to lower jaw 217. Such a configuration allows for a shearing action when lower jaw 217 is closed upon upper jaw 223. The jaws 217 and 223 can also be configured for a cleaving action wherein the jaws 217 and 223 contact directly along the cutting surface, rather than sliding past each other. In one embodiment, upper jaw 223 is unitarily formed as a part of cutter housing 216.

In operation, robot 201 operates by dragging its tail and the hook portion of lower jaw 217 behind it to catch wire 215. Once caught, as depicted in FIG. 2, wire 215 contacts switch assembly 212 via switch lever 213 to thereby signal to robot 201 that wire 215 is positioned adjacent lower jaw 217 and upper jaw 223. Effectively, switch lever 213 has sensed that wire 215 is in a cutting position. As described above, switch assembly 212 can moderate the cutting motion of jaws 217 and 223. Switch 212 can therefore automatically instruct motor 218, wait for the operator to instruct motor 218, or be configured to sense wire 215, among other configurations.

If activated to sever wire 215, motor 218 is powered and controlled via control/power wires 214. Switch assembly 212, as described above, allows motor 218 to be operated. Power is thus provided over control/power wires 214 from robot 201 to motor 218. In an embodiment, motor 218 actuates or otherwise powers worm 210 at a low speed such that worm 210 is driven and thereby rotated. Following activation of the motor to close the jaws, the device can include logic that activates the motor in the reverse direction to return the jaws to the open position after the wire is cut.

As described above, worm gear 211 interlock with the threads of worm 210. Worm 210 is rotated in such a direction that the non-hook end of lower jaw 217 moves distal the body of robot 201. As a result of the C-shape of lower jaw 217, the hook end of lower jaw 217 moves proximate the body of robot 201, and specifically, towards upper jaw 223. This rotation is possible due to the axle provided by dowel pin 219. To completely sever wire 215, lower jaw 217 is closed upon upper jaw 223. The blade of the hook end of lower jaw 217 allows for the shearing of wire 215. Jaws 217 and 223 can also be configured for a cleaving action wherein jaws 217 and 223 contact directly along the cutting surface, rather than sliding past each other.

Once wire 215 is severed, lower jaw 217 can be rotated back to its hook position by the opposite operation of motor 218 and thus worm 210. For example, motor 218 actuates or otherwise powers worm 210 to rotate in such a direction that the non-hook end of lower jaw 217 moves proximate the body of robot 201. As a result of the C-shape of lower jaw 217, the hook end of lower jaw 217 moves distal the body of robot 201, and specifically, away from upper jaw 223. In an embodiment, during operation where no cutting or catching is desired, lower jaw 217 can be closed or remain closed after wire 215 severing to prevent the unwanted catching of environmental objects, as depicted in FIG. 4.

The embodiments above are intended to be illustrative and not limiting. Additional embodiments are within the claims. In addition, although aspects of the present invention have been described with reference to particular embodiments, those skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the invention, as defined by the claims.

Persons of ordinary skill in the relevant arts will recognize that the invention may comprise fewer features than illustrated in any individual embodiment described above. The embodiments described herein are not meant to be an exhaustive presentation of the ways in which the various features of the invention may be combined. Accordingly, the embodiments are not mutually exclusive combinations of features; rather, the invention may comprise a combination of different individual features selected from different individual embodiments, as understood by persons of ordinary skill in the art.

Any incorporation by reference of documents above is limited such that no subject matter is incorporated that is contrary to the explicit disclosure herein. Any incorporation by reference of documents above is further limited such that no claims included in the documents are incorporated by reference herein. Any incorporation by reference of documents above is yet further limited such that any definitions provided in the documents are not incorporated by reference herein unless expressly included herein.