RELATED APPLICATION

The present application claims the benefit of U.S. Provisional Application No. 61/548,627 entitled MOTORIZED ROBOT TAIL SYSTEM, filed October 18, 2011, which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention is directed to portable land based surveillance robots that can be transported into an area of operation. Specifically, the present invention is directed to ground based robots having a modular motorized robot tail for improving the overall stability and performance of the robot.

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. 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 around or over the obstacles 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 reveal any adversaries. 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 herein incorporated by reference in their entirety. Typically, the land based robots are driven along the ground to scout for adversaries. 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 certain land based robots are intended be thrown over certain obstacles, the robot must still be driven onto the area to be surveyed and overcome the terrain between the landing spot and the area to be surveyed. Larger robots with wider wheel bases and more wheels are often better able to navigate difficult terrain or obstacles. However, the larger robots are typically heavier and bulkier making transport of the robots more arduous and difficult. While smaller robots are more easily transportable, the smaller robots are often unable to navigate the terrain as effectively.

Accordingly, there is a need for land based robot that is small enough to be effectively transported into the field by an infantry unit while being capable of maneuvering over difficult terrain.

SUMMARY OF THE INVENTION

A throwable or aerial droppable land based robot, according to an embodiment of the present invention, comprises a robot body having a first set of motorized wheels defining a front track and a detachable tail assembly having a second set of motorized wheels defining a rear track parallel to the front track. The robot body comprises an elongated housing with one of the first set of motorized wheels positioned at each end of the housing. The housing containing control circuitry, motors, transceiver, and other processing circuitry. The tail assembly comprises an elongated tail having a connecting flange and electrical connector at one end to engage the tail to the elongated housing, wherein the second set of motorized wheels can be positioned at the opposite end of the elongated tail such that the elongated tail defines the wheel base for the robot. An alternate conventional tail and alternate payload tail may also be attached to the robot body.

In one aspect, the robot body houses the essential systems for the land based robot such that the robot body can be maneuvered with only the first set of motorized wheels and is conventional . In this configuration, the connector of the tail assembly comprises a control and power connection for operation the motor systems for the second set of wheels contained within the secondary housing. The tail assembly can be attached to the robot body to space the first and second sets of motorized wheels apart to define an elongated wheel base between the front and rear tracks. When attached, the increased wheel base provided by the tail assembly improves the overall stability of the robot during maneuvering allowing the robot to navigate more difficult terrain and obstacles than with only the first set of motorized wheels.

In one aspect, the second set of wheels can be narrowly spaced such that the rear track is narrower than the front track. In this configuration, each of the second set of wheels can be positioned against or proximate to the end of the elongated tail to streamline the overall footprint of the tail assembly when the tail assembly is disconnected from the robot body. The streamlined footprint of the tail assembly allows the tail assembly to be more efficiently packed and transported by infantry soldiers, while maintaining the stability advantages of three or four contact points between the robot and the ground. In one aspect, the first and second sets of motorized wheels can be operated independently to improve the performance of the robot. The first set of wheels can be operated to engage an obstacle to provide a motive (pulling) force and elevate the robot body while the second set of wheels provides an additional motive (pushing) force to assist the robot in overcoming the obstacle. Similarly, the first and second set of wheels can be operated in tandem to maintain constant motive force as the robot ascends difficult grades or over loose terrain. In addition, depending on the orientation of the robot and the intended direction of travel, the rearmost pair of wheels can be operated such that the primary source of motive force is from the rearmost pair of wheels. The "rear-wheel" drive arrangement allows for more efficient movement of the robot when the robot is moving across level ground thereby reducing the energy consumption of the robot and correspondingly the size of the power source and replacement power sources that must be transported with the land based robots. In one aspect, each wheel of the first and second sets can be individually powered such that the wheels can be independently rotated to assist in the steering of the robot. In this configuration, the left wheels of the first and second sets of wheels and right wheels of the first and second sets of wheels can be rotated in opposite directions to "skid-steer" the robot. Alternatively, each of the wheels can be rotated in the same direction to improve the overall power of the robot.

In one aspect, tail assembly can comprise a flexible joint permitting some angular rotation of the second set of wheels in a horizontal plane around the flexible joint. The side -to-side rotation of the second set of wheels permits the second set of wheels to rotate and pivot around obstacles or find lines through sections of terrain that may otherwise engage the second set of wheels and prevent forward motion of the robot. The flexible joint can allow the secondary housing and second set of wheels to be moved vertically relative to the elongated housing and the first set of wheels. The flexible joint can flex as to raise or lower the second set of wheels as the robot traverses uneven terrain to maintain constant contact between the first and second set of wheels and the ground as the robot moves. The flexible joint is biased to maintain the second set of wheels at a predetermined height relative to the first set of wheels, wherein flexing the joint to raise or lower the second set of wheels creates a spring force for returning the second set of wheels to the original position relative to the first set of wheels. A land based robot, according to an embodiment of the present invention, comprises a robot body and a set of detachable tail assemblies. The robot body further comprises an elongated housing with a first set of motorized wheels defining a front track. The detachable tail assemblies further comprises alternative tails. For example, an elongated tail having a connector assembly at one end for connecting the elongated tail to the housing of the robot body and a second set of motorized wheels at the other end of the elongated tail, wherein the second set of motorized wheels define a rear track. In another example, the tail may have a payload such as an auxiliary battery or sensors, audio capabilities, in another embodiment the tail may be a conventional tail as in Patent Publication US 2001/0152922 incorporated herein by reference. 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 an attached tail assembly according to an embodiment of the present invention.

Figure la is a plan view of a robot body without an attached tail. Figures lb, lc, and Id are different tail assemblies attachable to the robot body.

Figure le is a view of the connector including a connecting flange and an electrical connector of the tails of Figures lb and Id.

Figure If is a rear elevational view of the connector portion of the robot body.

Figure 2 is a top view of the land based robot depicted in Figure 1. Figure 3 is a bottom view of the land based robot depicted in Figure 1.

Figure 4 is a front view of the land based robot depicted in Figure 1.

Figure 5 is a side view of the land based robot depicted in Figure 1.

Figure 7 is a schematic view 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 shown in FIGS. 1-5, a land based robot 10, according to an embodiment of the present invention, comprises a robot body 12 and a detachable tail assembly 14. The robot body 12 can further comprise an elongated housing 16 and a first set of motorized wheels 18 defining a front track, wherein a wheel of the first set of motorized wheels 18 is positioned at each end of the elongated housing 16. The detachment tail assembly 14 further comprises an elongated tail 20 having a connector assembly 22 at one end of the tail 20 and a secondary housing 23 at the opposite end of the tail 20. The tail assembly 14 also comprises a second set of motorized wheels 24 defining a rear track parallel to the front track when the tail assembly 14 is mounted to the robot body 12, wherein a wheel 24 of the second set of motorized wheels 24 is positioned on either side of the secondary housing 22. Typically the robot will be throwable, for example a robot weighing less than 3 pounds with the attached tail assembly. In other embodiments less than 5 pounds. In other embodiments less than 2 pounds.

As shown in FIGS. 1-5, in one aspect, the connector assembly 22 of the tail assembly 14 comprises a mount configured as a connecting flange 26, an electrical connector 28 and fasteners 30, such as screws. In this configuration, the elongated housing 16 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. The various tails will have similar mounts to selectively allow attachment to the robot body and the mounts are suitably usable in the field at points of surveillance. The tail of Figure lc is conventional, the tail of Figure Id allows a payload such as an auxiliary battery or accessory electronics to be carried by the robot and selectively attached. An embodiment of the invention is a kit with a plurality of selectively attachable tails with differing functions and or capabilities.

As shown in FIGS. 1-5, in one aspect, each wheel 18, 24 of the first and second set of wheels 18, 24 comprises a plurality of radial climbing elements 36 extending radially outward from the edge of the wheel 18, 24. The radial climbing elements 36 allows for improved traction of the wheel 18, 24 as well as an engagement surface for gripping obstacles and lifting the wheel 18, 24 up the obstacle. In one aspect, the radial climbing element 36 can be aligned with a spindle 38 of the wheel 18, 24, wherein the radial climbing element 36 is an extension of the spindle 38. In one aspect, each radial climbing element 36 further comprises a secondary protrusion 40 angled from the end of the radial climbing element 36 to further improve the engagement of the wheel 18, 24 to obstacles and terrain to further improve the traction of each wheel 18, 24. The secondary protrusion 40 is adapted to flex relative to the radial climbing element 36 to further grip obstacles and provide a springing force for assisting the wheel 18, 24 as the wheel 18, 24 climbs the obstacle.

In one aspect, each wheel 18, 24 is individually motorized such that each wheel 18, 24 can be individually rotated. The wheels 18, 24 can be operated in the same direction to four wheeled propulsion of the robot 10. Alternatively, either the first set of wheels 18 or the second set of wheels 24 can be operated independently to provide either "front-wheel drive" or "rear-wheel drive" operation of the robot 10. The wheels 18, 24 can be used to turn the robot 10 by rotating one wheels 18, 24 of each pair of wheels 18, 24 in the opposite direction of the other wheel 18, 24 of the corresponding pair of wheels 18, 24 to skid turn the robot 10. Alternatively, only the wheels 18, 24 of one of the pair of the wheels 18, 24 are rotated in opposite direction to turn the robot 10. In one aspect, the first set of wheels 18 can be rotated at a different rotational speed than the second set of wheels 24. When climbing an obstacle, the first set of wheels 18 can be rotated at a slower rotational speed to maintain constant contact and engagement of the first set of wheels 18 to obstacle while the second set of wheels 24 rotates more quickly to generate forward motive force.

As depicted in FIGS. 1-6, in one aspect, the second set of wheels 24 can comprise a smaller diameter than the first set of wheels 18. In one aspect, the diameter of the first set of wheels 18 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, the diameter of the wheels 24 of the second set of wheels 24 can be less than 75% of the diameter of the wheels 18 of the first set of wheels 18. In other aspects, the second set of wheels 24 can by less then 66% or 50% of the diameter of the first set of wheels 18. In this configuration, the larger first set of wheels 18 can more easily climb obstacles or difficult terrain. Similarly, the smaller second set of wheels 24 serves to provide forward motive force during travel across level terrain or while the first set of wheels 18 climbs or overcomes obstacles. In one aspect, the tail 20 can be shaped to provide clearance for the elongated housing 16 and the secondary housing 22 while maintaining contact with the ground with both sets of wheels 18, 24. As depicted in FIG. 3, the elongated tail 20 can comprise a flexible joint 44 permitting rotation of the secondary housing 23 and second set of wheels 24 in a horizontal plane around the flexible joint 44. The side-to-side rotation of the second set of wheels 24 permits the second set of wheels 24 to rotate and pivot around obstacles or find lines through sections of terrain that may otherwise engage the second set of wheels 24 and prevent forward motion of the robot 10.

In one aspect, the flexible joint 44 can allow the secondary housing 22 to be elevated or lowered relative to the elongated housing 16 and correspondingly moving the second set of wheels 24 vertically relative to the first set of wheels 18. The joint 44 is biased to return the second set of wheels 24 to the same relative position to the first set of wheels 18. In this configuration, the second set of wheels 24 can move vertically as the robot 10 moves to adapt to changing or uneven terrain. In one aspect, the second set of wheels 24 can brace the first set of wheels 18 as the first set of wheels 18 engage a climb and obstacle. The weight of the elongated housing 16 and the first set of wheels 18 as the first set of wheels 18 climb an obstacle will flex the joint 44 creating a spring force that braces the second set of wheels 24 against the ground beneath the robot 10 and pushing the first set of wheels 18 onto the obstacle improving the engagement of the first set of wheels 18 to the obstacle. Once the first set of wheels 18 clears the obstacle the flexed joint 44 will straighten to further propel the first set of wheels 18 onto the obstacle.

As depicted in FIGS. 1-6, in one aspect, the front track defined by the first set of wheels 18 can be longer than the rear track defined by the second set of wheels 24. The more closely spaced second set of wheels 24 reduces the overall footprint of the tail assembly 14 when disengaged from the elongated housing 16 for more efficient packing of the disassembled robot 10. In one aspect, the first set of the wheels 18 can be spaced about 4 inches (10 cm) to 8 inches (20 cm) apart. In one aspect, the distance between the second set of wheels 24 can be less than or about 75% of the distance between the first set of wheels 18. In another aspect, the distance between the second set of wheels 24 can be less than or about 50% of the distance between the first set of wheels 18. The triangular shape defined by the ends of the front track and the narrow rear track provides the advantages of a wide wheel base for the robot 10 without the large foot print required for large rectangular shaped wheel bases with equal length front and back tracks.

In one aspect, as depicted in FIG. 6 the elongated housing 16 can comprise a power supply 46, a controller system 48 and a communication system 26 for wirelessly linking the robot 10 to a remote control 50. The remote control 50 is adapted to communicate instructions to the controller system 48 for operation of the robot 10. The connector assembly 22 can further comprise at least one power connector 42 for linking the second set of the wheels 24 to the power systems contained within the elongated housing 16. In one aspect, the secondary housing 22 can comprise a secondary or backup power supply 54 for operating the second set of wheels 24 alone or both sets of wheels 18, 24. Similarly, the connector assembly 22 can further comprise at least one controller connector 44 for linking the control systems for the motors of the second set of the wheels 24 to the controller system contained within the housing 16. In one aspect, the elongated housing 16 of the robot 10 can further comprise a surveillance system 52 comprising at least one camera 52 for communicating images or video to the remote control 50.

In one aspect, the elongated housing 16 contains all the essential system for operating the robot 10 such that the robot 10 can be operated with or without the tail assembly 14. Operating the robot 10 without the tail assembly 14 allows the robot 10 to be thrown a greater distance or with more accuracy. In one aspect, the weight of the robot 10 without the tail assembly can be less than or about 4 lbs and alternatively less than or about 2 lbs. Alternatively, the tail assembly 14 can be attached to the robot 10 to allow for improved maneuverability and handling of the robot 10 over open or difficult terrain. In one aspect, the weight of the robot 10 with the tail assembly can be less than or about 6 lbs and alternatively less than or about 4 lbs such that the robot 10 can still be thrown even with the attached tail assembly 14. The flexibility of the robot 10 allows operators to adjust the robot 10 configuration according to the particular situation.

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.