Patent Description:
This application is related to <CIT> and <CIT>, The '<NUM> patent also claims priority to the <NUM>/<NUM>,<NUM> provisional application.

Throwable robots used in military and policing operations need to be robust and able to survive exposure to rugged conditions including exposure to dirt and water and large vertical drops. Providing modularity and flexibility in attaching useful accessories that may be securely attached thereto and that would be protected from damage during use would be welcome by users. The interchangeability of accessories is of particular interest to military and law enforcement personnel as this allows a single robot to be reconfigured to meet certain mission specific needs. Any improvements in adding functionalities, reliability and performance for robots used in high stakes military and police operations are desirable. In particular, improvements in protecting accessories attached to throwable robots, would be well received by users of such robots. Document <CIT> discloses a two wheeled robot with convertibility and accessories. Document <CIT> discloses a robotic two-wheeled vehicle.

A combination throwable two wheeled robot with one or more removable accessory packs provide functional options for the robot that may be swapped out in the field by users. In embodiments, the one or more accessory packs are protected from damage upon impacts resulting from throws or drops by way of utilizing existing features and the geometries of such two wheeled robot and specific features, configurations of the accessories. The accessory, configured as a backpack attachable to the robot, may be secured to the body of the robot where the tail would conventionally be, with the tail then secured to the backpack. In embodiments the accessory may protected from direct impacts when thrown by being positioned within a protected zone or envelope defined by the maximum deflection of the wheels. Additionally, the protected zone may be provided by the rearward projecting tail and its resistance to deflection upon impact. In embodiments, where the accessory protrudes beyond the zone of impact, an elastomeric bumper may be provided to the projection such that the elastomeric material absorbs the shock of impact rather than the accessory.

Known throwable two wheeled robots have an elongate body defining a chassis extending between and supporting a pair of drive wheels and further having a ground engaging tail extending rearwardly from the elongate body. Control circuitry, power circuitry, motors, drive trains, transceivers, cameras may all be located in the elongate body and thereby are protected by the compressible and resilient wheels and the integrity of the elongate body. In certain of such robots, the wheels may be compressed due to impacts from throwing or falls a limited amount, the elongate body is sized such maximum deflection or compression of the wheels upon a flat surface does not allow contact of the elongate body with the impact surface as clearance is provided between the maximum deflection point of the pair of wheels and the elongate body from impacts with flat surfaces. The space between the elongate body and the maximum deflection of the wheels provides a zone of protection to the accessories. The inventors have identified that impacts on accessories mounted to the robot that extend beyond the zone of protection, can directly damage the robot as well as the accessory. In embodiments, where the accessory protrudes beyond the zone of protection, an elastomeric bumper may be added. In embodiments, the accessory may have an elastomeric member sandwiched between the accessory and the elongate body, providing further protection to the robot.

The accessory packs may include a backpack containment that may be mountable on the chassis of the robot. In embodiments, the backpack unit defines a cavity that is covered by a cover. Suitable components are located in the backpack cavity dependent upon the functionalities of the backpack. The components including circuitry, the circuitry may be connected to circuitry in the elongate body by way of cables and connectors such as a USB connector. The accessory may then have an additional externally accessible USB connector. Such a connector may be a power port or a port for charging the robot or batteries in the accessory. In embodiments, the robot includes a tail having a mounting portion that is mountable to either a landing portion of the backpack or a landing portion of the robot chassis. In embodiments, when the backpack unit is placed on a rearward side of the body of the robot without the tail on the robot, before the backpack is secured with threaded fasteners attaching the backpack unit to the robot, the backpack unit has one degree of freedom of motion relative to robot, the one degree of freedom allowing the backpack unit to be pulled outwardly away from the robot. In embodiments, on an end view, both sides of the accessory may be simultaneously separated from the robot in a single outward direction. In embodiments, on an end view, one side of the accessory may be positioned in an undercut region such that the other side of the accessory is rotated outwardly about the one side before the one side may be separated.

In embodiments, each of the wheels have an undeflected radius, and each wheel is deflectable upon impact when thrown to a maximum deflected or deformed radius defining generally a cylindrical envelope and wherein the space between the elongate body and the outer periphery of the cylindrical envelope defining an annular accessory mounting space. In embodiments, the backpack unit is entirely within the annular accessory mounting space, when the robot interfacing portion of the backpack body is mated with the landing portion of the chassis and the tail interfacing portion of the backpack body is mated with mounting portion of the tail. In embodiments, the backpack body extends rearwardly from the robot chassis and the tail extends rearwardly from the backpack. In embodiments, the tail providing an additional protective envelope portion continuous with the accessory mounting space in that the tail has rigidity that precludes both wheels from simultaneously contacting or fully compressing to the maximum deflection level when the impact is on the tail side of the robot impacting a flat.

In embodiments, the body has four sides, a top side, a bottom side, a rearward side, and a forward side. The body comprising a chassis with sidewalls and exterior sidewall surfaces and providing an accessory mounting interface. The chassis having a side with a planar landing having a matrixical arrangement of threaded holes. The landing having an outwardly facing landing surface with hole openings at the landing surface. The landing having landing sides with sidewall surfaces extending in an inward direction for the landing. In embodiments, the landing with a planar landing surface has recesses therein spaced from the threaded holes. In embodiments the accessory mounting interface comprising at least two adjacent sides, each side having planar side surfaces with the planar surface on one of the two adjacent sides being perpendicular to the planar surface on the other of the two adjacent sides.

In embodiments, each of the at least two adjacent side surfaces have projections with outwardly facing landings, and the landings have a matrixical arrangement of threaded holes, the threaded holes extending toward the open interior but not into the open interior. In embodiments, the landing having a planar outwardly facing surface. The threaded holes being perpendicular to an outer surface of the landing. The projections having projection sidewall surfaces leading to the respective landing surface. The projections of each side being unitary with one of the chassis portions.

In embodiments, the accessory is attached within the cylindrical envelope. The accessory having mating projections that extend below the landing surfaces and are positioned to abut against projection sidewalls or positioned in recesses.

The accessory, when positioned on the exterior surface of the robot, may have a single degree of freedom. In embodiments the single degree of freedom is in the same direction as the axis of at least on threaded hole. The accessory may be attached with a plurality of threaded fasteners extending inwardly and being within the cylindrical envelope. The accessory may have surfaces for abutting with the projection sidewall surfaces and/or for fitting into recesses on the respective sides of the robot.

In embodiments the projections have a landing with projection side walls, the projection defining a rail attachment portion aligned with the axis of the elongate body, in embodiments the rail having a dovetail cross-section. In embodiments the rail may be configured as a Picatinny rail extending in a direction from wheel to wheel. The accessory having a clamp for attachment to the rail. The projections being unitary with chassis portions, the chassis portions defining a chassis interior that secures therein at least one motor, at least one battery, radio and control circuitry.

In embodiments, the at least one landing having inwardly extending recesses for capturing portions of the accessory. The recesses extending inwardly in the same direction as the threaded holes.

In embodiments, a forwardly directed camera is supported by the robot body. In embodiments, a plurality of robot components are mounted in an open interior of the chassis. In embodiments, the plurality of components include at least one motor, a circuit board with processing circuitry, and a battery.

In embodiments, a throwable robot has only two motorized wheels supported by a body, the body comprising a housing with a matrixical arrangement of threaded holes extending into an exterior surface of the housing, the matrixical arrangement extending at least most of the distance between the two wheels. In embodiments, the matrixical arrangement has at least one row of threaded holes in alignment, the at least one row comprising at least four holes. In embodiments, the row comprises at least three holes in alignment. In embodiments, the matrixical arrangement comprises at least two rows of threaded holes, with adjacent pairs of holes having equal spacing between the holes. In embodiments, at least two adjacent sides each have a matrixical arrangement of holes. The threaded holes not extending through the walls of the housing thereby maintaining a watertight integrity of the enclosure. In embodiments, the entries of the threaded holes comprising the matrixical arrangement are coplanar.

A feature and advantage of embodiments is that a robot and accessory combination having a weight that allows the combination to be thrown over obstacles such as fences and/or walls. In embodiments, the robot and accessory combination has a weight of less than five pounds.

In embodiments, the wheels are separated from each other a distance between <NUM> and <NUM> millimetres. The matrixical arrangement of mounting holes for backpack accessories have a separation between adjacent holes of about <NUM> millimetres. In embodiments, the hole separation is <NUM> to <NUM>,<NUM> millimetres. In embodiments, the length of the backpack accessory that seats on the top and/or back side of the elongate body is between <NUM> millimetres and <NUM>,<NUM> millimetres. The attachment holes are separated by <NUM> millimetres or a multiple of <NUM> millimetres such that the holes mate with the accessory backpack mounting holes on the elongate chassis.

A feature and advantage of embodiments is that a robot and accessory combination with a level of impact resistance/shock absorbing that allows the robot to continue a mission after experiencing a significant drop, such as driving off a floor of a multiple story building dropping to a floor below. In embodiments, the robot and accessory is configured to experience a three story drop without loss of functionality. The maximum deflectibility of the wheels when the robot is dropped <NUM> metres can define the zone of protection or annular mounting space for accessories.

In embodiments, the robot and accessory combination has a <NUM> metres drop rating, indicating that the combination can be dropped a distance of <NUM> metres without damage. In embodiments, each of the wheels deflect to a maximum deflection in a radial direction when dropped from <NUM> metres, and wherein when each of the wheels deflect said maximum deflection, the chassis and payload do extend outwardly to or past said maximum deflection. A feature and advantage of embodiments is that a robot with an accessory mounted thereto by threaded fasteners, such as screws, may be thrown and the accessory/robot interface distributes shear forces from impact of the robot with a floor or ground to abutting surfaces between the accessory and the robot rather than to the screws or threaded fasteners securing the accessory to the robot.

A feature and advantage of embodiments is that the matrixical arrangement of holes may be utilized for adjustable mounting accessories and portions of the robot. For example different tails may be utilized. And a specific tail may be mounted in different orientations to angularly position a forward facing fixed camera or accessory on the robot as desired. For example, the tail may be rotated <NUM> degrees to provide a different angle of viewing for a camera directed forwardly from the housing.

A feature and advantage of embodiments is a two wheeled robot having a chassis extending between two motorized radially deformable resilient wheels, and a tail extending rearwardly. The radially deformable resilient wheels having an undeformed radius, a flat surface operational deflection, and a maximum radial deformation on impact. The maximum radial deformation defining a cylindrical component protection envelope extending between the wheels. The flat surface operational deflection defining a cylindrical region and an obstacle clearance below the chassis. The two wheeled robot having with an integral accessory backpack assembly that is positioned on a top surface of the robot chassis and on a back side of the robot chassis. The integral accessory backpack assembly having an inverted L shape. In embodiments the chassis in cross section having a generally square shape with each of the top, bottom, front and back sidewalls having exterior planar surfaces. In embodiments the top sidewall and back sidewall having planar surfaces for mounting the L shaped accessory backpack assembly. The corner of the "L" positioned at an upper rear corner of the chassis. A feature and advantage of embodiments is that the mounting of the L shaped accessory backpack assembly on the top sidewall and back sidewall is such that it does not impede the clearance for obstacles below the chassis. A further feature and advantage is that optimal use of the component protection region is provided with the L-shaped integral accessory backpack assembly. In embodiments the component protection envelope is enlarged in a rearward direction by way of the tail extending from the upright leg of the L-shaped integral accessory backpack assembly, that is, the rearward portion of the backpack assembly. The tail having sufficient stiffness to preclude impact of the rearward components on the chassis with an impact surface. The tail and each wheel cooperating to extend the component protection envelope rearwardly allowing the rearward portion of the backpack assembly to extend rearwardly out of the cylindrical component protection envelope defined by the maximum deflection radius of the wheels. In embodiments, the component protection envelope can be adjusted rearwardly by swapping out tails of different rigidity, or lateral flexibility, or length, or physical configuration. Alternatively, the component protection envelope can be adjusted rearwardly by adding an additional tail. Similar to the wheels, each tail having a maximum deformation limit which provides a minimal distance from the chassis that the tail will extend in deformation upon impact with a surface. The component protection envelope defined by the geometric space about the robot that a flat surface that is impacted by the robot in all different impact orientations, will not intrude. A generally rigid tail will provide a component protection envelope that extends from a deformation radius of each wheel, taken at the outermost portion of the wheel at that radius, to the full length of the tail.

A feature and advantage of embodiments is an L-shaped integral accessory backpack assembly that is attached to both a top wall and a back wall of the chassis providing a highly robust connection that even if there is an impact on the backpack assembly, the integrity of the connection is maintained. In embodiments, the L-shaped integral accessory backpack assembly comprises a backpack unit that is attachable and removable to the back wall of the chassis with one degree of freedom, an operational unit is attached to the top wall and also attached to the backpack unit thereby providing an integrated L-shaped backpack accessory assembly.

In embodiments, the integral backpack assembly comprises a hermetically sealed backpack unit and a hermetically sealed operational top wall mounted unit. In embodiments, the backpack unit and the operation top wall mounted unit are electrically connected by a cable. In embodiments, the backpack unit is electrically connected to the robot. In embodiments, when the backpack unit is electrically connected to the robot, a port on the accessory can receiving charging power for charging the robot batteries.

The accessory interfaces may be utilized for mounting accessories such as sensor devices, munitions, communication hardware, illumination devices, gas dispensing devices, or devices with other functionalities. The accessory may be operated remotely by way of a remote controller that operates the robot. Communications circuitry and operational circuitry may be separate from or included in the remote controller that operates the robot. In embodiments, the accessories have a cooperating robot interface allowing the accessory to be attached directly to, or by way of an intermediate bracket, to the accessory interface of the robot. The accessory having surfaces that abut with the planar landing surface and surfaces that engage the chassis in the landing recesses or on the landing sidewall surfaces. Such an arrangement minimizes transfer of impact forces to fasteners attaching the accessory to the robot. In embodiments, the backpack units as described herein may be mounted on the topside and/or the backside of the elongate body of the two wheeled throwable robot.

As described herein, accessories are attached to throwable robots used in military and policing operations with the robot and attached accessory maintaining essentially the same robustness and the survivability of the robot without the mounted accessory thereby allowing the robot and attached accessory to survive exposure to rugged conditions including exposure to dirt and water and large vertical drops. As described herein, accessories attached to throwable robots provide modularity, flexibility, and interchangeability allowing a single robot to be reconfigured to meet certain mission specific needs.

Referring to <FIG>, a throwable two wheeled robot <NUM> that generally comprises an elongate body <NUM>, a pair of motorized wheels <NUM>, <NUM>, and a tail <NUM> centrally positioned between the wheels. The elongate body defining a chassis <NUM> for supporting componentry, such as a camera <NUM>, and having a forward side <NUM>, a rearward side <NUM>, a top side <NUM>, and a bottom side <NUM>. The chassis <NUM>, in embodiments, may be comprised of a pair of clam shell portions <NUM>, <NUM>. A seal ring <NUM> may provide sealing. One portion, a rear portion, having a deep recess <NUM> and the other a shallow recess <NUM>. The chassis defining an interior <NUM> that contains a pair of motors <NUM>, batteries, <NUM> and a circuit board <NUM>. The robot may be actuated by withdrawing a key <NUM> from a key slot <NUM>. The robot having an axis α extending through the rotational axis of the wheels and through the elongate body <NUM>. The robot is remotely controlled by radio from a user interface <NUM>. <FIG> illustrate a backpack accessory mounted on the rearward side <NUM> with the tail <NUM> mounted on the backpack accessory <NUM>.

Referring to <FIG>, <FIG>, and <FIG>, details of an exterior surface <NUM> of the chassis <NUM> are illustrated providing accessory mounting interfaces <NUM>, <NUM>, one on the top side of the body and one on the rear side of the body. The interface surfaces each comprising a projection <NUM> that has a landing <NUM> with a planar landing surface <NUM>, one or more threaded holes <NUM> extending from the planar landing surface <NUM>, and landing sidewall portions <NUM> with landing sidewall surfaces <NUM>. The landings may also have recesses <NUM> with chassis wall surfaces <NUM> defining the recesses. The holes defining a matrixical arrangement <NUM> of the holes having a length L1 that more than half (most of) the length L2 of the elongate body portion and more than half (most of) the distance between the wheels L3. In embodiments, there will be a line of threaded holes spaced about <NUM> millimetres apart in the direction of an axis of the elongate body. Additionally, holes will be spaced <NUM> millimetres from each other in a direction perpendicular to the line of holes parallel to the elongate body axis. In embodiments, particularly where the backpack accessory <NUM> is in the zone of protection provided by the maximum deflection of the wheels and/or the deflection resistance of the tail, as illustrated by <FIG>, the interface of the backpack accessory may be essentially planar, as best shown in <FIG> without the cooperating projection and recess structure described. <NUM> illustrates the planar seating surface <NUM> and the seating region <NUM> for the backpack accessory <NUM> as illustrated in <FIG>.

Referring to <FIG>, the elongate body <NUM> of the robot may provide a power supply port <NUM>, such as a USB port, for providing power to the backpack accessory. In embodiment, the housing may also have a pogo connector pad <NUM> for providing power to the backpack accessory. In embodiments, the power supply port may also be a charging port for the robot <NUM>.

Referring to <FIG>, illustrates a backpack accessory attached to the topside <NUM> of the elongate body. As illustrated, in embodiments, the tail may be attached to the rearward side <NUM> by selected ones of one of the matrixical arrangements of the threaded holes at a landing <NUM> by way of threaded fasteners such as screws <NUM> and may be rotated <NUM> degrees to put the tail at a different position indicated by the dashed lines labeled <NUM>. Another embodiment of a backpack accessory <NUM> may be attached to the chassis by a robot mounting interface <NUM> that includes surfaces <NUM> that abut the outwardly facing planar surfaces of the landing <NUM>. Projections <NUM> may fit into one of the recesses <NUM>. The accessory may wrap around and engage the rearward facing surface <NUM> of the rearward side of the chassis. The abutment of the accessory along surfaces that extend in the same direction as the axis <NUM> of the screws <NUM> allow the accessory to chassis interfaces to absorb shock that occurs upon impact after throwing the robot, rather than the screws. The arrangement of <FIG> provides, when the screws <NUM> are not connected, a one degree of freedom of movement, essentially moving the accessory in the direction D1.

The robot mounting interface of the accessory configured to cooperate with the accessory mounting interface of the robot chassis for providing the single degree of freedom of movement when the accessory is placed on the robot chassis for attachment thereto. The one degree of freedom may be provided by a C-shaped portion <NUM> as indicated by the dotted lines of <FIG>. The portions of the C-shape portion corresponding to the upper and lower legs of a C may extend on opposite sides of a landing, or more generally a projection, providing protection from the screw shearing off or coming out of the threaded hole. Although <FIG> is in two dimensions, as can be seen from the perspective figures the mounting structure of the chassis is in three dimensions.

Referring to <FIG>, in embodiments, the wheels have an undeformed or undeflected radius R1 and a maximum deformed radius condition that occurs under shock, such as upon impact when the robot is thrown or dropped to take the wheel to a maximum deflected radius R2. The radius R2 defining a cylindrical envelope E1. In operation, the wheels may slightly deform from the weight of the robot to an operational deflected radius R3, such as by tips <NUM> of the wheels slightly bending upon engagement with the floor or ground or other operational surface. The component protection envelope E1 is reflective of the maximum deflection expected of the wheels under normal impact conditions. The space between the envelope E1 and the body or chassis <NUM> defining the zone of protection or accessory mounting region <NUM>. The sizing of the accessory <NUM> may within the accessory mounting region <NUM> thereby protecting the accessory from impact when throwing the robot with attached accessory. As illustrated in <FIG>, the accessory may have a projecting portion <NUM> that extends beyond the zone of protection. In such an instance, impact with the accessory when the robot is thrown, can damage the accessory and/or the robot. An elastomeric bumper <NUM> may be installed on the projecting end of the accessory or other convenient location such that impact when thrown will most likely be at the elastomeric bumper <NUM> rather than with a non-resilient accessory housing or component.

The accessory may be a sensor device, a munition, communication hardware, illumination device, gas dispensing device, or devices with other functionalities. The accessory may be powered by the robot or may have its own power source. The accessory may have its own communications module for communicating with a remote operator or may utilize communications provided by the robot. In embodiments, the accessory mounting region <NUM> below the chassis is not utilized thereby providing clearance for obstacles such as rocks during forward movement of the robot.

Referring to <FIG>, in embodiments, a combination throwable two wheeled robot and backpack unit includes a backpack unit <NUM> coupled to a robot chassis <NUM>. For purposes of clarity of illustration, the wheels are removed from the robot in <FIG>. The robot <NUM> generally comprises an elongate body <NUM> and a pair of motorized wheels <NUM>, <NUM>. The backpack unit <NUM> may be mountable on the chassis <NUM> of the robot <NUM> using cooperating interfaces <NUM>, <NUM>. One interface <NUM> is configured as an elongate projection <NUM> with serpentine edges <NUM> and the other interface <NUM> has a recess <NUM> with serpentine edges <NUM>. The interfaces are conformingly shaped for providing a single freedom of movement for placement and removal of the backpack unit on the chassis. In embodiments, the backpack unit <NUM> has a backpack body <NUM> that defines a cavity <NUM> with backpack componentry <NUM>, such as circuitry, and control processors, radios, such as recievers or transceivers, and memory, and that is coverable by a cover <NUM>. The robot includes a tail <NUM> having a mounting portion configured as a flange <NUM> that is mountable to either a landing portion <NUM> of the cover <NUM> or a landing portion <NUM> of the robot chassis <NUM>. In embodiments, when the backpack unit is placed on the robot without threaded fasteners attaching the backpack unit to the robot, the backpack unit has one degree of freedom of motion relative to robot, the one degree of freedom allowing the backpack unit to be pulled outwardly away from the robot. In embodiments, the direction of removal is transverse to the axis of the elongate body. In embodiments, the direction of removal is perpendicular to the longest axis of the elongate body. In embodiments, the direction of removal is perpendicular to a rotational axis of the robot wheels.

Referring to <FIG>, and as discussed with reference to <FIG> above, in embodiments, each of the wheels <NUM>, <NUM> have an undeflected radius R1, and each wheel is deformable upon impact when thrown to a maximum deformed radius R2. In embodiments, the maximum deformed radius defines a cylindrical component protection envelope E1 extending between the wheels and the space between the elongate body and the cylindrical envelope defines an annular accessory mounting space <NUM>. In embodiments, the backpack unit <NUM> is entirely within the annular accessory mounting space when the robot interfacing portion of the backpack body is mated with the landing portion of the chassis and the tail interfacing portion of the backpack body is mated with mounting portion of the tail. The backpack body extends rearwardly from the robot chassis and the tail extends rearwardly from the cover of the backpack. In embodiments, the tail provides an additional component protection envelope E2 continuous with the accessory mounting space as best illustrated in <FIG>. The rigidity of the tail can be tailored to adjust the size of the additional component protection envelope E2.

Referring to <FIG>, in embodiments, the backpack unit may be attached to an additional operational unit <NUM> for providing components/sensors for selected functionality, including but not limited to TDS (Distraction / Gas / Explosives), speakers, cameras (thermal, backup, etc), CBRNE sensors, flashlights / strobe lights, microphone arrays, motion sensors / range finders, various actuators (e.g., actuators that pick up objects and actuators that release a payload), various radios, and explosives such as Thermite. The operational unit <NUM> may be secured to both the top wall of the robot and to the backpack unit. Referring to <FIG>, the operational unit is illustrated as having a portion <NUM> that extends out of the cylindrical component protection envelope E1 but is still contained within the tail extended component protection envelope E2.

Flashbang type munitions that may be suitable to be used as part of the backpack, some requiring modified actuation mechanisms are, for example <CIT>; <CIT>; <CIT>; <CIT>; <CIT>; and <CIT>.

Referring to <FIG>, various operational units suitable for attachment to the chassis of the robot and the backpack unit <NUM> are illustrated. <FIG> illustrate an LED unit <NUM> with a housing <NUM> defining a cavity <NUM>, backpack unit interface <NUM>, circuitry with LED's <NUM>. The LED unit <NUM> is secured to the backpack unit forming an integrated backpack assembly <NUM>. In profile, an end view, the assembly <NUM> has an L-shape. A cable, not shown, may extend from the LED unit to the backpack unit for powering the unit and otherwise integrating them.

Referring to <FIG>, another LED unit <NUM> is illustrated with a LED orienting portion <NUM> directing the LED's more forwardly than the embodiment of <FIG>. The LED unit attaches to the backpack unit <NUM> with screws <NUM> and extends over the top <NUM> of the robot and may be attached to the robot by screws <NUM> extending into select threaded holes of the matrixical arrangement of holes. In the example embodiment of <FIG>, the backpack unit <NUM> has a plurality of tail mounting interfaces <NUM>, and two of the interfaces are utilized for attachment of two tails <NUM>, <NUM>. Referring to <FIG>, utilization of two tails may adjust the component protection envelope E3 provided by the two tails enlarging the component protection envelope relative to the component protection envelope provided by one tail. <FIG> illustrates the LED unit <NUM> protected by elastomeric bumpers <NUM>, <NUM> that expand the zone of protection beyond that provided by the maximum wheel deflection diameter. The elastomeric bumpers may be attached by fasteners, such as screws, or rivets, or by way of adhesives or other methods known to those skilled in the art.

Referring to <FIG>, a backpack accessory <NUM> has an inverted L-shape when viewed on end, has a rearward or backside portion <NUM> and a topside portion <NUM>. The backside portion having a forward facing robot interface surface <NUM> for mounting on the robot. The topside portion having a lower surface <NUM> that confronts and may seat or mount on the topside of the robot. In embodiments, the topside portion has components that provides environmental effects or environmental sensing and the back side has housing <NUM> containing, for example, control circuitry, communications componentry, battery power. The back side may be securely attached to the rearward side <NUM> of the elongate body and has complex interface structure <NUM> comprising landings <NUM>, recesses <NUM>, and projections <NUM>, that cooperate with corresponding structure on the backside of the elongate body of the robot. Additionally, an attachment region <NUM> with threaded holes <NUM> is provided for attachment of the tail <NUM>. The topside portion having a chassis <NUM>, configured as a housing that contains operative elements <NUM>, <NUM> for sensing or effecting the environment into which the robot is thrown. The operative elements may be for example, speakers, munition cartridges, including flashbang cartridges, or sensors. The backpack accessory may have a connector <NUM>, such as a USB connector, for plugging into a power port <NUM> on the robot, such as shown in <FIG>. In embodiments, the power port of the two wheeled throwable robot operates as a charging port as well as a power out port. The backpack accessory may have a USB port <NUM> that allows the robot to be charged when the backpack accessory is mounted on the robot and the power port is utilized by the backpack accessory. That is, the backpack accessory circuitry allows the charging power provided to the accessory port <NUM> to be provided to the robot charging port <NUM>, as shown in <FIG>.

Referring to <FIG>, in another embodiment, a thermal imaging camera unit <NUM> is integrated with the backpack unit and in profile has an L shape. The backpack unit <NUM> is illustrated with a pair of antennas <NUM>, <NUM>. The backpack unit may have a supplemental transmitting and receiving functionality separate from the transmitting and receiving functionality of the robot. In embodiments, the antennas of the backpack unit may replace the antennas of the robot such as the antennas shown in <FIG>.

In embodiments, the backpack may have mounting holes and an area to route cables for each of the capabilities to be configured in manufacturing. In embodiments, the backpack is attached to robot through four screws and is powered through a USBC cable connected to the charging port on the robot.

In embodiments, the backpack is dimensioned and configured to fit between two wheels of the throwable robot. In embodiments, the backpack/accessory within the standard wheels may be rated to the same <NUM> metres drop rating as the throwable robot. In embodiments, the drop rating of the backpack/accessory is such that users may use the robot the same way every time whether or not the backpack/accessory is attached to the throwable robot. That is, particular accessory units may be contained within the component protection envelope. In embodiments, the backpack may be used with attachments that are too large to fit within an defined by the wheels and tail of the throwable robot. In such a case, the wheels may be replaced with larger wheels having a greater maximum deformation radius thereby increasing the size of the component protection envelope. Alternatively or additionally, a different or additional tail may be added to increase the envelope rearwardly. In embodiments, "maximal deformation" may be at the intended maximum drop distance. That is, the component protection envelope may be defined by the maximum deformation of the wheels and tail when the robot is dropped from <NUM> metres.

In embodiments, the backpack and/or accessory may be triggered though an operator control unit (OCU). In embodiments, the OCU has two buttons associated with backpack/accessory capabilities. In embodiments, a pushbutton may be used to trigger a desired action. In embodiments, a pushbutton may be pressed to enable a speaker, microphone, thermal camera, etc. In embodiments, a safety mechanism (e.g., a toggle switch and toggle guard in this case) is associated with a switch used to trigger a desired function. In embodiments, a switch with a safety mechanism is used to arm a TDS attachment.

<FIG> depict a backpack assembly <NUM> with POGO pins <NUM> and mounting structure suitable for particular functional units such as TDS payloads (Distraction / Gas / Explosives), not shown except with respect to the generic unit of <FIG> and <FIG>. With reference to <FIG>, mounting holes are seen on the top surface and the hole on the top left is used to route cables if needed.

Claim 1:
Two wheeled throwable robot (<NUM>) and backpack accessory (<NUM>) comprising:
a pair of motorized wheels (<NUM>, <NUM>) mounted on each end of an elongate body; (<NUM>)
a backpack accessory providing active sensing or environmental effects and having a forward facing surface of the rearward portion attached to the rearward side (<NUM>) of the elongate body, a stabilizing tail (<NUM>) extending from a rearward surface of the rearward portion of the backpack accessory, the backpack accessory electrically connected to the elongate body;
characterized in that
the backpack accessory is attached to an interface at the rearward side of the throwable robot, and in that the interface also receives a tail when the backpack accessory is not in place.