RELATED APPLICATION

The present application claims the benefit of U.S. Provisional Application No. 61/548,623 entitled IMPACT ABSORBING WHEEL ASSEMBLY, filed October 18, 2011, and U.S. Provisional Application No. 61/679,422 entitled EXTENDED STABILIZING TAIL FOR MICRO-ROBOTS ADAPTED FOR RECONNIAISSANCE OPERATION, filed August 3, 2012, both which are incorporated herein by reference in their entirety.

FIELD OF THE INVENTION The present invention is directed to portable land based surveillance robots that can be thrown for a distance before being driven on to the target. Specifically, the present invention is directed to land based robots having impact absorbing wheel assembly for absorbing the impact of the robot being thrown or falling and having at plurality of molded climbing features for improving the climbing ability of the wheels. The land based robot also having a stabilization tail for stabilizing the robot as the wheel assembly climbs over an obstacle.

BACKGROUND OF THE INVENTION

In combat situations, soldiers can gain considerable advantage over adversaries by learning the location, number and condition of the adversaries. However, the inherent risk of scouting for adversaries or using vantage points to visually observe adversaries is that the adversaries may detect or determine the location of the soldiers and correspondingly gain an advantage over the soldiers. Similarly, in urban situations soldiers may be forced to move through buildings containing adversaries where soldiers may encounter and engage adversaries in close quarters as the soldiers move through building placing the soldiers at considerable risk. In addition, certain building features such as stairwells, doorways and hallways can form bottlenecks in which soldiers are at heightened risk of ambush. Similarly, outdoor environments can also provide similar obstacles to visual surveillance as obstacles such as walls, fences, berms, buildings, rock formations and the like can conceal adversaries while simultaneously exposing soldiers to hostile threats as soldiers maneuver to observe the adversaries. Difficult terrain can bottleneck maneuvering soldiers forcing soldiers in into dangerous choke points where the risk ambush is particularly high. Recently, small scale aerial drones have seen increased use with infantry as a portable means of scouting enemy positioning with minimal risk to the soldiers. Typically, the aerial drones comprise small fixed wing airplanes that orbit over the area of operation to provide a top down view of the area to adversarial positions. The advantage of small scale aerial drones is that the drones are inherently low weight for flight and accordingly are easily transportable by infantry units. However, the inherent drawback of aerial drones is that the aerial drones typically cannot be flown indoors and provide minimal benefit in areas with heavy top cover that prevents the aerial drone from clearly observing the area from above. Small portable land based robots, such as disclosed is US Patent Publication No.

2010/0152,922 and US Patent No. 7,559,385, have also seen increased use as a land based alternative to aerial drones when aerial drones cannot be used or are ineffective. The above references are incorporated herein by reference in their entirety. The land based robots are typically sized to allow the robot to be thrown a portion of the distance between the deployment point and the intended vantage point or through a window or door way before being driven along the ground to scout for adversaries. Throwing the robot improves the versatility of the robot allowing the robot to be quickly positioned proximate to the desired vantage point or allowing the robot to be placed strategically, such as being a possible adversary location. As such, the robot is often thrown a considerable distance or through a window to reach the desired landing point. The wheels of the robot are typically positioned at the sides of the robot and are often the portion of the robot that first strikes the window or the ground taking the brunt of the impact. If the wheels are damaged from the impact the robot will unable to properly move or at all rendering the vehicles effectively useless. While the wheel can be reinforced with metal reinforcements and thicker structural components, the reinforcement substantially increases the weight of the robot and the moment of inertia of the wheel increasing the power required to efficiently rotate the wheel. Accordingly, the structural integrity and survivability of the wheel must be weighed against the corresponding increases in the weight of the wheel and required power output from the motors for rotating the wheel. A similar consideration is that unlike aerial drones that are flown well above the area of operations, the land based robots must be driven over often difficult terrain and obstacles to maneuver around the area of operations. While larger wheels are more effective at navigating obstacles or difficult terrain, the larger wheels are bulkier and can be significantly heavier than smaller wheels making the robot more difficult to transport and throw. Accordingly, larger diameter wheels often have thinner spokes, hubs or rims to reduce the overall weight of the wheel and the power necessary to rotate the wheel. However, the reduced support structure increases the likelihood that the wheel will become damaged when thrown toward the intended target.

A related concern for land based robots is maintaining a stable orientation of the robot as the robot navigates obstacles and over difficult terrain. In particular, robots climbing uneven obstacles are particularly prone to flipping or tipping as one or more of the wheels are in the process of climbing the obstacle. Land based robots are often not directly visible to the operator while the robot is being driven onto the target. Instead, the operator is typically forced to rely solely on a camera mounted on the front or top of the robot to guide the robot to the target. The robot is traveling over difficult terrain the robot may become flipped or awkwardly angled and the operator may be unable to view the robot to determine the exact posture of the robot to correct the orientation of the robot. Similarly, the robot might be oriented following being tipped that the operator may not be able to remotely correct the orientation of the robot.

Accordingly, there is a need for a land based robot capable of surviving the impact of the robot against the ground or window following being thrown and capable of traveling across difficult or uneven terrain. Similarly, there is a need for a land based robot capable of safely climbing obstacles with minimal risk of tipping.

SUMMARY OF THE INVENTION

A land based robot, according to an embodiment of the present invention, can comprise a robot body having an elongated tail and at least one wheel positioned on either side of the robot body. The robot is adapted to be thrown or dropped before being driven onto the desired location. Each wheel has an internal frame having a central hub, an outer ring or rim, a plurality of spokes linking the central hub to the outer ring, wherein the frame comprises a high durometer polymer or composite material for resisting deformation of the frame upon impact with the ground or other object when the robot is thrown. In addition, each wheel is overmolded with a polymer or composite material having a lower durometer than the polymer or composite of the internal frame for absorbing and dissipating the energy from the impact. The combination of the rigid internal frame and softer, more durable overmolded layer was found to improve the survivability of the wheel when the robot is thrown without the aid of heavier metal reinforcements. The lighter weight wheels are more efficiently rotated by the robot motors than heavier metal or metal reinforced wheels thereby improving the overall efficiency and operating time of the robot. Similarly, the lower weight of the wheel reduces the strain on the operator when carrying or throwing the robot.

In an embodiment of the present invention, each wheel can further comprise a plurality of climbing elements positioned along the exterior of the outer rim of the frame. Alternatively, each spoke can comprise a climbing element at the end of the spoke, wherein the ring is positioned between the climbing element and the central hub to maintain the spacing of the spokes. Each climbing element comprises a primary stem extending radially outward along a radial axis transverse to the central rotational axis of the wheel. Each climbing element can also comprise a foot portion extending from the end of each primary stem along a secondary axis transverse the radial axis of the corresponding stem such that each climbing element defines an L-shaped scoop, claw or engagement structure. The foot portion comprises the lower durometer polymer or composite material of overmolded coating and can flex relative to the primary stem when the wheel is rotated such that the tip of the foot portion engages an obstacle or hard surface. The flexing of the foot portion against the obstacle or hard surface provides an opposing spring force against the rotation of the wheel improving the engagement of the climbing element to obstacle or surface as well as providing a spring force for propelling the wheel forward as the climbing element disengages from the obstacle or hard surface. In one aspect, the frame can further comprise a plurality of protrusions extending from the exterior of the rim defining a rigid core for each of the primary stem to prevent flexing of the stem as the foot portion flexes from engaging an obstacle or hard surface. In one aspect, the plurality of climbing elements can comprise a first set of climbing element each having a long stem and a second set of climbing elements each having a short stem, wherein the long stem climbing elements are arranged in an alternating arrangement with the short stem climbing elements. The longer stem of the long stem climbing elements positions the corresponding foot portion further away from the central rotational axis of the wheel than the shorter stems of the short stem climbing elements. The closer proximity of the foot portions of the short stem climbing elements allows the wheel to be rotated closer to an obstacle without engagement of one of the climbing elements to the obstacle. The continued rotation of the wheel can then rotate the foot portion of a long stem climbing element into the engagement with obstacle, wherein the closer proximity of the wheel to the obstacle and the longer stem of the long stem climbing element allows the foot portion of the long stem climbing element to engage the obstacle further from the edge of the obstacle reducing the likelihood that the climbing element will inadvertently disengage as the wheel continues to rotate.

In an embodiment of the present invention, the land based robot can further comprise an elongated tail having a tail member for contacting the ground behind the robot during operation of the robot. The tail member generally extends along a central axis bisecting the central point between the wheels of the robot. The tail member provides a secondary contact point between the robot and the ground that cooperates with the primary contact points provided by the wheels to provide a three or more point connection between the robot and ground, without substantially increasing the weight of the robot. The tail member can comprise two wings engagable to the ground and extending rearward from the end of the elongated tail along an axis transverse to the central axis defined by the tail member. The transverse axis of the wings permits the wings to engage the ground on either side of the central axis limiting rotation of the robot around the central axis during normal travel of the robot or as the robot climbs obstacles. In addition, the spread wings can maintain the alignment of the robot as the wheels of the robot engage an obstacle to the lift the robot. Similarly, the wings are positioned to engage the ground as the robot moves across level ground to prevent rotation of the robot body around the rotational axis of the wheels and maintaining an even camera picture from cameras mounted on the robot body.

In one aspect, the elongated tail can comprise a high durometer polymer or composite material to define a rigid tail to maintain the tail member against the ground as the robot moves across the terrain. Similarly, the tail member can comprise durable polymer or composite material having a lower durometer than the elongated tail to improve the longevity of the tail member. In one aspect, the tail member can comprise an angled front edge to prevent the tail member from catching on their terrain or obstacles as the robot travels over the terrain. In one aspect, the elongated tail comprises a flexible joint that flexes to permit rotation of the tail member in a horizontal plane around the flexible joint. The side-to-side rotation of the tail member can be used to dislodge the wings from any obstacles or debris that may become engaged to the tail member as the robot travels across the ground. In another aspect, the joint is flexed to allow the tail member to rotate in a vertical plane around the joint. In this configuration, climbing an obstacle with the wheels applies a rearward axial force along the length of the tail to engage the end of the tail to the ground. As the robot continues to the climb and the axial angle relative to the ground defined by the elongated tail increases, the weight of the robot can cause the joint to flex creating a spring force pressing the end of the tail into the ground and the wheels into the obstacle being climbed. Upon reaching the top of the climb and a portion of the robot's weight exceeding a predetermined amount supported by the obstacle tail straightens providing a springing force further propelling the robot over the end of the obstacle. In another aspect, the elongated tail is entirely rigid preventing flexing of the tail as the robot climbs. In this configuration, the tail member directly supports the robot body and wheels as the wheels climb the obstacle before being pulled up the obstacle after the wheels reach the top of the obstacle.

A wheel for a land based robot, according to an embodiment of the present invention, comprises a frame, a drive axle connector and a polymer coating, wherein the frame comprises a first polymer having a first durometer and the polymer coating comprises a second polymer having a second durometer less than the first durometer. The frame further comprises a central hub, an outer ring and a plurality of spokes linking the central hub to the outer ring. The drive axle connector is affixable to the central hub and defines a port for receiving a drive axle of a motor for rotating the wheel. The polymer coating is overmolded over the frame and at least a portion of the drive axle connector to affix the adapter to the frame. In one aspect, the adapter comprises a lip positioned against the central hub and providing a larger overlap between the adapter and the frame to reinforce the engagement of the adapter to the frame when the polymer coating is overmolded.

In one aspect, the rigid frame further comprises a plurality of stems extending from the outer ring, wherein each stem extends along a radial axis traverse to the central rotational axis of the wheel. In this configuration, the over molding of the polymer coating also forms a flexible foot extending from the end of each stem, wherein the flexible foot extends along a secondary axis traverse to the radial axis of the corresponding stem. The stems and attached feet define a plurality of paddles positioned around the periphery of the outer ring. In one aspect, the plurality of paddles comprise at least one long paddle and at least one short paddle, wherein the stem of the long paddle is longer than the stem of the short paddle such that the foot of the long paddle is positioned further from the outer ring than the foot of the short paddle. In this configuration, the long paddles and short paddles can be arranged in alternating order around the periphery of the outer ring.

A robot tail, according to an embodiment of the present invention, comprises a mount at one end for affixing the robot tail to a robot body and a tail member positioned at the other end. The tail member further comprises at least two wings extending rearward from the tail member along an axis transverse to the central axis of the robot. In one aspect, the wings can further comprise a swept back front edge of the tail member to defect debris or obstacles away from the contact element to prevent the tail member from catching on the terrain or obstacles. In one aspect, the tail member can comprise at least one unpowered wheel that maintains the secondary contact point between the tail member and the ground while reducing the friction associated with dragging a contacting element along the ground. Similarly, the tail member can comprise at least one tab extending generally rearward from the tail member and having an edge parallel to the central rotational axis, wherein the tab proves an elongated engagement point between the tail member and the ground as the wheels climb the obstacle to prevent tipping of the robot.

The above summary of the various representative embodiments of the invention is not intended to describe each illustrated embodiment or every implementation of the invention. Rather, the embodiments are chosen and described so that others skilled in the art can appreciate and understand the principles and practices of the invention. The figures in the detailed description that follow more particularly exemplify these embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which:

Figure 1 is a perspective view of a land based robot with a pair of wheels according to embodiment of the present invention without detachable tail.

Figure 2 is an exterior side view of a wheel according to an embodiment of the present invention.

Figure 3 is an exterior perspective view of the wheel depicted in Figure 2. Figure 4 is a top view of the wheel depicted in Figure 2.

Figure 5 is an interior side view of a wheel depicted in Figure 2.

Figure 6 is an interior perspective view of the wheel depicted in Figure 2.

Figure 7 is a schematic side view of a wheel according to an embodiment of the present invention.

Figure 8 is a schematic view of a wheel, according to an embodiment of the present invention, climbing an obstacle.

Figure 9 is a schematic view of a wheel, according to an embodiment of the present invention, climbing an obstacle.

Figure 10 is an exploded perspective view of a wheel according to an embodiment of the present invention.

Figure 11 is a cross-sectional side view of a wheel according to an embodiment of the present invention.

Figure 12 is a perspective view of a wheel according to an embodiment of the present invention.

Figure 13 is a perceptive view of a wheel frame according to an embodiment of the present invention with a rim attached.

Figure 14 is a perceptive view of a wheel frame according to an embodiment of the present invention with the rim removed.

Figure 15 is a perspective view of a robot having an elongated tail according to an embodiment of the present invention.

Figure 16 is a top view of the robot depicted in Figure 15.

Figure 17 is a front view of the robot depicted in Figure 15.

Figure 18 is a side view of the robot depicted in Figure 15.

Figure 19 is perspective view of an elongated tail for a robot according to an embodiment of the present invention.

Figure 20 is perspective view of tail member for a robot according to an embodiment of the present invention. Figure 21 is a schematic diagram of a robot illustrating the spacing of the wings according to an embodiment of the present invention.

Figure 22 is a schematic diagram of a robot illustrating the spacing of the wings according to an embodiment of the present invention. Figure 23 is a top view of a tail member having a plurality of stabilization tabs according to an embodiment of the present invention.

Figure 24 is a top view of a tail member having a longitudinal support according to an embodiment of the present invention.

Figure 25 is a top view of a tail member having two secondary supports according to an embodiment of the present invention.

Figure 26 is a top view of a tail member having a free spinning wheel positioned at the end of each wing according to an embodiment of the present invention.

Figure 27 is a top view of a tail member having a free spinning wheel positioned at the end of each wing and an additional free-spinning wheel at the center of the cross- support according to an embodiment of the present invention.

Figure 28 is a top view of a tail member having a free spinning wheel positioned at the end of each wing and an additional free-spinning wheel at the center of the cross- support, wherein the center free-spinning wheel is contained within a cage according to an embodiment of the present invention. Figure 29 is a side view of a free-spinning wheel with a ratchet assembly according to an embodiment of the present invention.

Figure 30 is a top view of a tail member having a mesh contact surface according to an embodiment of the present invention.

Figure 31 is a schematic diagram of a robot according to an embodiment of the present invention.

While the invention is amenable to various modifications and alternative forms, specifics thereof have been 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

As depicted in FIG. 1, a land based robot 10 for use with at least one wheel 12, according to an embodiment of the present invention, comprises a robot body 14 containing control systems, communications systems 16 and a motor system for rotating the wheels 12. As depicted, the robot 10 comprises a dual wheel robot 10 with a single wheel 12 positioned on either end of the robot body 14. In this configuration, the motor system comprises a motor corresponding to each wheel 12 and having a drive axle for rotating the corresponding wheel 12. In one aspect, the diameter of the wheels 12 can comprise about 4 inches (10 cm) to 8 inches (20 cm) in diameter and about 6 inches (15 cm) in diameter. In one aspect, each wheel 12 can comprise between 0.20 lbs and 0.300 lbs, wherein the overall weight of the robot 10 can range from about 1.0 to 1.3 lbs. In another aspect, the robot 10 can be less than 5 lbs or weight that can be easily thrown. As depicted in FIGS. 1-7, each wheel 12, according to an embodiment of the present invention, comprises a frame 18, a drive axle connector 20 and an overmolded polymer coating. The frame 18 comprises a central hub 22, an outer ring 24 and a plurality of spokes 26 supporting the outer ring 24 on the central hub 22. As depicted in FIGS. 10- 12, in one aspect, the outer ring 24 can be positioned between the end of the spokes 26 and the central hub 22 such that a portion of each spoke 26 extends radially past the outer ring 24. In this configuration, the outer ring 24 can be separate component attached to spokes 26 of the frame 18. The ring 24 can comprise a metal that when combined with the high durometer polymer or composite frame 18 can increase the impact absorption and survivability of the wheel 12. The drive axle connector 20 is affixed to the central hub 22 of the frame 18 and defines a port 26 for receiving the end of the drive axle for the corresponding motor, wherein the rotating the drive axle rotates the outer ring 24 of the frame 18 around a central rotational axis a-a defined by the drive axle.

The frame 18 comprises a rigid polymer including, but not limited to, a nylon polymer having a durometer of about 110 on the Rockwell scale. The rigid polymer or composite material provides the structural support for the wheel 12 to maintain the shape of the wheel 12 during normal operation of the wheel 12. Specifically, the rigid outer ring 24 distributes impact energy across the wheel 12 to portions of the wheel 12 not directly impacted as the robot 10 is thrown, wherein the distributed impact energy is dissipated over a larger portion of the wheel 12 to further minimize risk of deformation or damage to the wheel 12. In one aspect, the spokes 26 can comprise an energy dissipative material including, but not limited to urethanes, elastomeric polymer or thermoplastics. Similarly, the polymer coating comprises a durable polymer overmolded onto the frame 18 including, but limited to polyurethane having a durometer between 15A to 95 A or 38D to 80D on the shore durometer scale. In one aspect, the adapter 20 further comprises a lip 28 shaped to interface with the central hub 22, wherein the over-molding of the polymer coating onto the frame 18 and the adapter 20 seals the lip 28 to the central hub 22. As depicted in FIG. 10, in one aspect, the adapter 20 can comprise a threaded end 56 insertable through the central hub 22 and secured with a threaded fastener 58 and a washer 60 attached to the threaded end 56.

As depicted in FIGS. 1-7, each wheel 12, according to an embodiment of the present invention, further comprises a plurality of climbing elements 30 spaced along the periphery of the outer ring 24. In one aspect, each climbing element comprises a primary stem 32 extending radially outward from the frame 18 along a radial axis b-b transverse to the central rotational axis a-a and a flexible foot 34 extending from the end of the primary stem 32, wherein the foot 34 extends along a secondary axis c-c transverse to the radial axis b-b. In one aspect, the secondary axis c-c is offset by 30 to 90 degrees from the radial axis b-b. As depicted in FIGS. 12-14, the climbing elements 30 can be positioned at the end of each spoke 26.

As depicted in FIGS. 8-9, during operation, the wheel 12 is rotated by the drive axle such that the climbing elements 30 are rotated around the periphery of the wheel 12, wherein the angled foot 34 acts as a scoop for gripping soft terrain to propel the robot 10 forward. When engaging an obstacle or hard surface, the foot 34 flexes to increase area of engagement between the paddle 30 and the obstacle or hard surface as depicted in FIG. 9. The increased engagement area improves the force transfer through the paddle 30 as the wheel 12 rotates. The flexing of the foot 34 also provides a spring force as the foot 34 returns to its original position as the paddle 30 disengages from the obstacle or hard surface as the wheel 12 continues to rotate.

As depicted in FIGS. 1-8, in one aspect, the climbing elements 30 further comprises a set of long stem climbing elements 30a and a second short stem climbing elements 30b arranged in an alternating configuration around the periphery of the outer ring 24. The long climbing elements 30a comprise a long primary stem 32a, while the short climbing elements 30b comprise a short primary stem 32b shorter than the long primary stem 32b. The short primary stem 32b of the short climbing elements 30b allows the wheel 12 to be rotated closer to the obstacle or hard surface without engaging the obstacle with the short paddle 30b as depicted in FIG. 8. The continued rotation of the wheel 12 then engages the subsequent long paddle 30a into engagement with the obstacle, wherein the closer proximity of the wheel 12 to the obstacle increases the engagement area of the long paddle 30a to the obstacle as depicted in FIG. 9. The increased engagement area further improves the force transfer through the paddle 30a from the rotation of the wheel 12.

As depicted in FIGS. 15-18, in an embodiment of the present invention, the robot 10 can further comprise an elongated tail 36 having a mount 38 for affixing the end of the tail 36 to the robot body 14 and a tail member 40 at the opposite end of the tail 36. The tail 36 is affixable to the robot body 14 and also generally defines a center axis d-d that intersects the central rotational axis a-a of the wheels 12. In one aspect, the tail member 40 can further comprise at least two wings 42 for engaging the ground and extending radially outward from the end of the tail 36 along an axis e-e transverse to the center axis d-d defined by the tail 36. As depicted in FIGS. 21-22, in one aspect each transverse axis e-e can be about 45 to 60 degrees offset from the center axis d-d. As depicted in FIGS. 19-20 and 28, the tail member 38 can further comprise a tether point 62 for securing a leader, tether or other lead line to the robot 10.

In operation, the elongated tail 36 positions the tail member 40 to engage the ground behind the robot 10, wherein the tail member 40 prevents the rotation of the robot 10 around the central rotational axis a-a of the wheels 12. Similarly, the offset of the wings 42 prevents the rotation of the robot 10 around the center axis d-d as the robot 10 moves around the ground, thereby limiting ability of the robot 10 to tip. When the wheels 12 are lifted off the ground while climbing an obstacle, the weight of the robot 10 creates an axial force that is transmitted through the tail 36 and along the transverse axes of the wings 42. The offset angle of the wings 42 creates countering horizontal forces that prevent the robot 10 from tipping horizontally as the robot 10 climbs the obstacle.

As depicted in FIGS. 23-25, in one aspect, the tail member 40 can further comprise at least one cross-support 44 extending between the ends of the wings 42 such that the tail member 40 defines a generally triangular shape. The cross-support 44 provides an elongated engagement point extending along an axis parallel to the central drive axis a-a. The elongated engagement point further prevents the tipping of the robot 10 around the center axis d-d or side to side tipping of the robot 10 when the wheels 12 are climbing an obstacle. In one aspect, the tail member 40 can further comprise at least one longitudinal support member 68 extending between the cross-support 44 and the junction of the wings 42 as depicted in Figure 23. The longitudinal support member 68 strengthens the tail member 40 preventing flexing of the tail member 40. In one aspect, the tail member 40 can further comprise at least one secondary support member 70 extending between the cross-support 44 and at least one of the wings 42 as depicted in Figure 24. The secondary support member 70 strengthens the tail member 40 preventing flexing of the tail member 40.

As depicted in FIGS. 23-25, in one aspect, the tail member 40 can comprise a plurality of stabilization tabs 46 extending rearward from the cross-support 44, wherein the ends of each stabilization tab 46 are aligned along an axis parallel to the central drive axis a-a. The stabilization tabs 46 effectively provide the elongated engagement point of the continuous edge of the cross-support 44, while reducing the actual contact surface area between the tail member 40 and the ground to reduce the friction between the tail member 40 and the ground during movement of the robot 10.

As depicted in FIGS. 26-28, in one aspect, the tail member 40 can further comprise at least one free-spinning wheel 48. The wheel 48 provides the secondary contact point between robot 10 and the ground to stabilize the robot 10 without the added friction of dragging a stabilizing element across the ground. As depicted in FIG. 29, in one aspect, the wheel 48 can comprise a ratcheting assembly 50 that only allows the wheel 48 to freely spin in one direction. Specifically, the wheel 48 is adapted to spin in the forward direction with the robot 10 as the robot 10 is moving forward. When the robot 10 is moving in reverse or climbing an obstacle creating a rearward axial force against the tail member 40, the ratcheting assembly 50 locks to prevent the wheel 48 from rotating and allowing the wheel 48 to act as a static stabilizer supporting the robot 10. As depicted in FIG. 28, in one aspect, the tail member 40 can further comprise a wheel cage 52 encircling at least one of the wheels 48. The wheel cage 52 provides a contact surface for engaging the ground as well as protecting the wheel 48.

In one aspect, each wing 42 can further comprise a swept back front edge 54 for preventing engagement of obstacles and debris to the tail member 40 is pulled along the ground. Similarly, as depicted in FIG. 19, in one aspect, the elongated tail 36 can comprise a flexible joint 54 permitting rotation of the tail member 40 in a horizontal plane around the flexible joint 54. The side -to-side rotation of the tail member 40 permits the wings 42 to rotate and pivot around obstacles that may otherwise engage the wings 42 and prevent forward motion of the robot 10.

In one aspect, the flexible joint 54 can allow the tail member 40 to be elevated or lowered relative to the robot body 14 as the tail member 40 travels over uneven terrain. The joint 54 is biased to return the tail member 40 to the same relative position to robot body 14. In one aspect, the tail member 40 can brace the wheels 12 as the wheels 12 engage a climb and an obstacle. The weight of the robot body 14 and wheels 12 flex the joint 54 creating a spring force that braces the tail member 40 against the ground beneath the robot 10 and pushing the wheels 12 into the obstacle improving the engagement of the wheels 14 to the obstacle. Once the wheels 14 clears the obstacle the flexed joint 54 will straighten to further propel the wheels 14 onto the obstacle. As depicted in FIG. 30, the tail member 38 can alternatively comprise a frame 64 and a mesh 66 stretched across the frame 64. The mesh 66 provides a secondary contact point that can engage the ground to effectively provide a second contact point with less actual contact area to reduce the friction between the tail element 40 and the ground. In this configuration, the tail element 40 can further comprise stabilization tabs 46 for supporting the robot 10 when the wheels 12 climb an obstacle.

In one aspect, as depicted in FIG. 31, the robot body 14 can comprise a power supply 72, a controller system 74 and a communication system 78 for wirelessly linking the robot 10 to a remote control 80. The remote control 80 is adapted to communicate instructions to the controller system 74 for operation of the robot 10. In one aspect, the robot body 14 can further comprise a surveillance system 82 comprising at least one camera 84 for communicating images or video to the remote control 80.

While the invention is amenable to various modifications and alternative forms, specifics thereof have been depicted by way of example in the drawings and described in detail. It is 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.