Ground pressure detonation device

A ground pressure detonation device includes a housing, a foot coupled to the housing, and an oscillation subsystem associated with the housing configured to oscillate the housing such that the foot impacts the ground with sufficient oscillating force to ensure detonation of one or more pressure sensitive explosive devices in and/or on the ground.

FIELD OF THE INVENTION

This invention relates to a ground pressure detonation device.

BACKGROUND OF THE INVENTION

Pressure sensitive explosive devices buried in or on the ground, such as land mines, ground surface Improvised Explosive Devices (IEDs) detonators, and the like, may be cleared by vehicles equipped with a mine flail. A typical mine flail includes a rotating drum adorned with metal chains. The chains impact the ground with substantial force as the drum spins, causing land mines to detonate. Mine flails may have many sizes, e.g., from large tank-mounted devices to smaller devices attached to robots. However, conventional small, robot-mounted devices may have difficulty generating enough force to guarantee mine detonation.

Another conventional approach to clearing and/or detonating the pressure sensitive explosive devices described above may be to use heavy ground rollers. As the name implies, these devices typically include of one or more rolling mass(es) which impart a ground pressure as they are moved across terrain of interest for clearing. The ground pressures from the rollers are designed to be sufficiently high so as to detonate the mines, IEDs, detonators and similar devices in the path. However, achieving sufficient pressures may be difficult and may often require extremely massive roller systems.

BRIEF SUMMARY OF THE INVENTION

In one aspect, a ground pressure detonation device is featured. The device includes a housing, a foot coupled to the housing, and an oscillation subsystem associated with the housing configured to oscillate the housing such that foot impacts the ground with sufficient oscillatory force sufficient to ensure detonation of one or more pressure sensitive explosive devices in and/or on the ground.

In one embodiment, oscillation subsystem may be configured to oscillate the housing such that the housing and the foot bounce up and down off the ground and the foot impacts the ground with the sufficient oscillatory force. The oscillation subsystem may include at least one moveable mass and a drive subsystem configured to oscillate the housing. The subsystem may include two wheels and the at least one moveable mass includes a mass attached to each of the two wheels. The drive system may include a motor coupled to the two wheels configured to rotate the two wheels in a counter-rotating direction with respect to each other such that the masses on each of the two rotating wheels oscillate the housing. The device may include a spring between the foot and the housing configured to store energy to the oscillation subsystem when the housing contacts the foot and the foot contacts the ground and configured to return energy to the oscillation subsystem as the foot and the housing bounce away from the ground. The spring and/or the drive subsystem may be configured to tune the amount of the oscillating force and/or the amount of the bounce. The spring and/or the drive subsystem may be configured to create a resonant condition that transfers energy into the oscillating force. The frame may be configured as a cylinder and the at least one moveable mass is in the cylinder. The drive subsystem may include a detonation subsystem configured to create repeated explosions in the cylinder to drive the mass in a downward vertical direction. The device may include a spring in the cylinder configured to drive the mass in an upward vertical direction. The downward vertical direction and the upward vertical direction of the mass may create the oscillating force. At least one moveable mass may be in the housing and the drive system may be configured to move the mass in a downward vertical direction and an upward vertical direction to create the oscillating force. The drive system may include a voice coil actuator subsystem configured to move the mass in a downward vertical direction and a spring configured to move the mass in an upward vertical direction to create the oscillating force. The drive subsystem may include a crank and a connecting rod coupled to the at least one mass configured to move the mass in a downward vertical direction and an upward vertical direction to create the oscillating force. The oscillation subsystem may include a plurality of arms extending from the housing each having masses coupled thereto and a drive system for moving the arms and masses to create the oscillating force. The drive system may include a motor coupled to the a ns. The oscillation subsystem may include torsional springs coupled to the arms configured to control the motion of the arms. The device may include a spring between the foot and the housing configured to store energy to the oscillation subsystem when the housing contacts the foot and the foot contacts the ground and configured to return energy to the oscillation subsystem as the foot and the housing bounce away from the ground. The spring and/or the drive subsystem may be configured to tune the amount of the oscillating force and/or the amount of the bounce. The spring and/or the drive subsystem may be configured to create a resonant condition that transfers energy into the oscillating force. The drive system may include a flexure extending through the housing configured to form said arms and a motor configured to drive a cam in contact with the flexure to deflect the flexure and drive the arms to create the oscillating force. The housing may include an upward port and a downward port and the drive system includes a jet engine and a spinning plate in the housing configured to alternately direct thrust to the upward port and the downward port to oscillate the housing to create the oscillating. The device may include a spring between the foot and the housing configured to store energy to the oscillation subsystem when the housing contacts the foot and the foot contacts the ground and configured to return energy to the oscillation subsystem as the foot and the housing bounce away from the ground. The spring and/or the drive subsystem may be configured to tune the amount of the oscillating force and/or the amount of the bounce. The spring and/or the drive subsystem may be configured to create a resonant condition that transfers energy into the oscillating force. The housing may be tilted in a predetermined direction such that the ground pressure device bounces in a desired direction. The housing may be titled in a predetermined direction such that the ground pressure device bounces over one or more obstacles.

In another aspect, a ground pressure detonation device is featured. The device includes at least one mass, a foot coupled to the mass, a spring coupled between the foot and the mass, and a drive subsystem configured to repeatedly move the mass in a downward vertical direction. The spring is configured to drive the mass in an upward vertical direction. The downward vertical direction and the upward vertical direction of the mass causes the mass to oscillate such that the foot impacts the ground with sufficient oscillating force to ensure detonation of one or more pressure sensitive explosive devices in and/or on the ground.

In one embodiment, the mass and the spring may be configured to oscillate the mass such that the mass and the foot bounce up and down off the ground and the foot impacts the ground with the sufficient oscillatory force. The spring and the mass may be configured to tune the amount of the oscillating force and/or the amount of the bounce. The spring and the mass may be configured to create a resonant condition that transfers energy into the oscillating force. The mass may be tilted in a predetermined direction such that the ground pressure device bounces in a desired direction. The mass may be titled in a predetermined direction such that the ground pressure device bounces over one or more obstacles.

In yet another aspect, a ground pressure detonation device is featured. The device includes at least one mass and a drive system configured to repeatedly drive the mass in a downward vertical direction such that the mass impacts the ground with sufficient oscillating force to ensure detonation of at least one pressure sensitive explosive device in and/or on the ground.

In one embodiment, the mass may be tilted in a predetermined direction such that the ground pressure device bounces in a desired direction. The mass may be titled in a predetermined direction such that the ground pressure device bounces over one or more obstacles.

DETAILED DESCRIPTION OF THE INVENTION

As discussed in the Background section above, pressure sensitive explosive devices buried in the ground are typically cleared by vehicles equipped with a mine flail or a mine roller. A mine flail typically includes a rotating drum adorned with metal chains. The chains impact the ground with substantial force as the drum spins, causing land mines to detonate. Mine flails come in many sizes, from large tank-mounted devices to small devices attached to robots.FIG. 1shows an example of conventional mine flail10attached to tank12.FIG. 2shows an example of flail14attached to robot16. However, there may be problems with conventional mine flail technology. The large size of the flail makes them unsuitable for clearing narrow paths that are not large enough for vehicles to traverse. The flails are not man-portable which may limit the locations at which mine clearance can be performed. Small mine flails may have problems generating enough force to trigger some mines.

Another approach to detonating pressure sensitive explosives buried in or on the ground is conventional rollers. Like flails, rollers can be mounted in front of tanks, trucks, or similar armored vehicles. Smaller rollers can be used with Bobcats, small tractors, robots, and the like, to attempt to detonate the pressure sensitive explosives.FIG. 3shows an example of conventional roller18mounted to truck20.FIG. 4shows an example of conventional roller22to smaller vehicle24.

Rollers may have the same shortcomings of flails discussed above. Similarly, small rollers may have problems generating sufficient force to trigger some pressure sensitive explosives.

The ground pressure detonation device of one or more embodiments of this invention overcomes the problems associated with conventional flails and rollers discussed above by providing a small, man-portable device that provides sufficient force needed to detonate pressure sensitive explosive devices in or on the ground.

Ground pressure detonation device30,FIG. 5, of one embodiment of this invention includes housing32and foot34coupled to housing32. Ground pressure detonation device30also includes oscillation subsystem36associated with housing32configured to oscillate housing32, e.g., in the direction indicated by arrow46, such that foot34impacts ground42with sufficient oscillatory force43to ensure detonation of one or more pressure sensitive explosive devices44in and/or on the ground42. In one example, housing32oscillates in direction46and foot34remains stationary on ground42. In this example, housing32contacts foot34which impacts ground42with oscillatory force43. In another example, foot34and housing32may bounce up and down off ground42(shown in phantom), indicated by arrow48, and impact ground42with sufficient oscillatory force43. When device30bounces up and down off ground42, device30can be advanced in a desired direction while preferably “hopping” over obstacles, such as tree roots, stones, debris, and the like.

In the example shown, oscillation subsystem36includes two counter-rotating wheels50,52with masses56,58attached thereto. Motor70may be used with belt64linking motor70to drive one of wheels50,52, e.g., wheel50to rotate wheels50,52in a counter rotating manner with respect to each other, e.g., as shown by arrows66,68. Motor70may be a brushed DC motor, an air motor, a brushless DC motor, an induction motor, an internal combustion motor, or similar type motor. The rotation of wheels50,52with masses56,58is preferably slaved together using gears60,62, a timing belt, and linkages or controls (not shown). As wheels50,52counter-rotate, the lateral portion of the centrifugal force balances out, creating net oscillating vertical motion46of housing32that causes foot34to impact ground42with sufficient oscillatory force43to ensure detonation of one or more pressure sensitive explosive devices44in and/or on the ground42.

The result is ground pressure detonation device30effectively and efficiently detonates pressure sensitive devices in and/or on the ground. Device30is a small, man-portable device and overcomes the problems associated with conventional flails and rollers discussed above.

In one design, device30may include spring72attached to bottom74of housing32and foot34. Spring72stores energy to oscillation subsystem36when housing32contacts foot34which impacts ground42and returns energy to oscillation subsystem36as device30bounces away from ground42saving drive power. The oscillatory force of foot34on ground42and the amount of bounce of foot34and housing32on and off ground42can be tailored by selection of the stiffness of spring72and/or the rotation rate of wheels50,52. Additionally, spring72and/or the amount of rotation of wheels50,52may be used to create a resonant condition of housing32and/or foot34which efficiently transfers the input energy into oscillatory force43that impacts ground42.

In one exemplary operation, the ground pressure detonation device30,FIG. 6, of one embodiment of this invention may be attached to a small robot, e.g. small robot76. By raising or lowering the attachment point to the robot to housing32of device30, line of action80can be changed slightly from a strictly vertical orientation, causing device30to travel in a desired direction, e.g., hop backwards or forwards. The change in line of action80essentially makes device30self-propelling.

A photograph of one example of a proof-of-concept prototype ground pressure detonation device30is shown inFIG. 7. In this example, the proof-of-concept device weighs approximately 27 lbs. In operation, the oscillatory force of device30,FIGS. 5-15, on ground42may exceed 600 lbf.

Ground pressure detonation device30a,FIG. 8, where like parts have been given like numbers, of another embodiment of this invention preferably includes housing32′ configured as a cylinder as shown with moveable mass82therein. The cylinder may be similar to a cylinder of an internal combustion engine or similar type device. In this example, oscillation subsystem36includes detonation subsystem84configured to create small repeated explosions, e.g., gas explosion86, which drive mass82in downward vertical direction88. Mass82impacts bottom90of housing32′ and bounces in upward vertical direction92. Device30may included spring91configured to tune the response of mass82with bottom90of the housing32. The downward and upward movement of mass82in housing32′ oscillates housing32′ and foot94, preferably in net oscillating vertical motion96, such that foot94impacts ground42with sufficient oscillatory force93to ensure detonation of one or more pressure sensitive explosive devices44in and/or on the ground42. Preferably, the downward and upward movement of mass82in housing32′ to create a resonant condition of housing32′ and foot94which efficiently transfers the input energy into oscillatory force93that impacts ground42. When device30abounces up and down off ground42, device30acan be advanced in a desired direction while preferably “hopping” over obstacles, such as tree roots, stones, debris, and the like. Device30amay also include an additional spring72,FIG. 5, and an additional foot34that may operate in a similar manner as device30.

Ground pressure detonation device30b,FIG. 9, where like parts have been given like numbers, of another embodiment of this invention is similar to device30,FIG. 5, except, in this example, oscillation subsystem36is configured as voice coil actuator100. Voice coil actuator100may be any known voice coil actuator known by those skilled. In one example, voice coil actuator100includes magnets102coupled to moveable mass104and stationary coils106affixed to housing32. Voice coil actuator100is preferably configured to drive mass104in downward vertical direction108. Spring110coupled to mass104and housing32drives mass104in upward vertical direction112. The downward vertical and upward vertical movement of mass104inside housing32oscillates housing32, preferably in net oscillating vertical motion114, such that foot34impacts ground42with sufficient oscillatory force43to ensure detonation of one or more pressure sensitive explosive devices44in and/or on the ground42. In one example, housing32oscillates in direction114and foot34remains stationary on ground32. In this example, housing32contacts foot34which impacts ground42with sufficient oscillatory force43. In another example, foot34and housing32may bounce up and down off ground42(shown in phantom), indicated by arrow115, and foot34impacts ground42with sufficient oscillatory force43. When device30bbounces on and off ground42, device30bcan be advanced in a desired direction while preferably “hopping” over obstacles, such as tree roots, stones, debris, and the like. Similar to device30,FIG. 5, device30b, may include spring72in a similar manner. The oscillatory force of foot34,FIG. 9, on ground42and the amount bounce of foot34and housing32up and down from ground42may be tailored by selection of the stiffness of spring72and/or spring110and/or the amount of linear motion provided by voice coil actuator110. Additionally, spring72and/or spring110and/or voice coil actuator100may be used to create a resonant condition of device30bwhich efficiently transfers the input energy into oscillatory force43that impacts ground42.

Ground pressure detonation device30c,FIG. 10, where like parts have been given like numbers, of another embodiment of this invention preferably includes oscillation subsystem36that includes arms120and122that extend from housing32with masses124and126attached thereto, respectively. Motor128is preferably coupled to aims120,122and drives arms120,122with masses124,126in downward vertical direction130and upward vertical direction132to oscillate housing32, preferably in net oscillating vertical motion134, such that foot34impacts ground42with sufficient oscillatory force43to ensure detonation of one or more pressure sensitive explosive devices44in and/or on the ground42. In one example, housing32oscillates in direction134and foot34remains stationary on ground32. In this example, housing32contacts foot34which impacts ground42with sufficient oscillatory force43. In another example, foot and housing32may bounce up and down off ground42(shown in phantom), indicated by arrow144, and impact ground42with sufficient oscillatory force43. When device30cbounces up and down off ground42, device30ccan be advanced in a desired direction preferably while “hopping” over obstacles, such as tree roots, stones, debris, and the like.

Device30calso preferably includes torsional springs140and142coupled to arms120and124, respectively, which may limit the motion of arms120,122. Motor128preferably drives arms120,122by moving through small displacements instead of a full rotation. Preferably, motor128is driven with an oscillating voltage/torque to bring device30cinto resonance.

Device30cmay include spring72that functions similar as discussed above. The oscillatory force of foot34on ground34and the amount of bounce of foot34and housing34on and off ground42as can be tailored by selection of the stiffness of spring72and/or springs140,142and/or the rate of motor128. Additionally, spring72and/or springs140,142and/or arms120,122may be used to create a resonant condition of housing32and foot34which efficiently transfers the input energy into oscillatory force43that impacts ground42.

Ground pressure detonation device30d,FIG. 11, where like parts have been given like numbers, of yet another embodiment of this invention, is similar to ground pressure detonation device30c,FIG. 10, except, in this example, detonation device30d,FIG. 11, includes single flexure150that forms arms120,122with masses124and126attached thereto. Flexure150is preferably pinned at points152and154. A rotating motor (not shown) attached to cam156causes flexure150to deflect as it spins to drive masses124and126in downward vertical direction130and upward vertical direction132to oscillate housing32, preferably in net oscillating vertical motion134, and in the correct phase, preferably bringing system30dinto resonance, such that foot34impacts ground42with sufficient oscillatory force43to ensure detonation of one or more pressure sensitive explosive devices44in and/or on the ground42.

Ground pressure detonation device30e,FIG. 12, where like parts have been given like numbers, of another embodiment of this invention preferably includes oscillation subsystem36′ configured as pulse jet160configured to apply a sequence of pulses162towards mass164. Pulses162cause mass164to travel in downward vertical direction such that mass foot34impacts ground42with sufficient oscillatory force43to ensure detonation of one or more pressure sensitive explosive devices44in and/or on the ground42. In one example, housing32oscillates in direction163and foot34remains stationary on ground42. In this example, mass164contacts foot34which impacts ground42with sufficient oscillatory force43. In another example, mass164and foot34may bounce up and down off ground42(shown in phantom), indicated by arrow165, and foot34impacts ground42with sufficient oscillatory force43. When device30ebounces up and down off ground42, device30ecan be advanced in a desired direction preferably while “hopping” over obstacles, such as tree roots, stones, debris, and the like.

Device30emay include spring72that functions similar as discussed above. The oscillatory force of foot34on ground42and mass162and foot34as they bounce up and down off ground42can be tailored by selection of the stiffness of spring72and/or the amount of force provided by pulses162. Additionally, spring72and/or the amount of force provided by pulses162may be used to create a resonant condition of device30ewhich efficiently transfers the input energy into oscillatory force43that impacts ground42.

Ground pressure detonation device30f,FIG. 13, where like parts have been given like numbers, of another embodiment of this invention is similar to device30,FIG. 5, except, in this example, oscillation subsystem36is configured as crank170and connecting rod172coupled to mass174. A motor (not shown) drives crank170causing mass174to move in downward vertical direction176and upward vertical direction178to oscillate housing32, preferably in net oscillating vertical motion180, such that foot34impacts ground42with sufficient oscillatory force43to ensure detonation of one or more pressure sensitive explosive devices44in and/or on the ground42. In one example, housing32oscillates in direction180and foot34remains stationary on ground42. In this example, housing32contacts foot34which impacts ground42with sufficient oscillatory force43. In another example, foot and housing32may bounce up and down off ground42(shown in phantom), indicated by arrow182, and foot34impact ground42with sufficient oscillatory force43. When device30dbounces up and down off ground42, device30dcan be advanced in a desired direction preferably while “hopping” over obstacles, such as tree roots, stones, debris, and the like.

Device30fmay include spring72that functions similar as discussed above. The oscillatory force of foot34,FIG. 13, on ground42and housing32and foot34as they bounce up and down off ground42can be tailored by selection of the stiffness of spring182and/or the rate of rotation of crank170. Additionally, spring72and/or the rotation of crank170may be used to create a resonant condition of device30fwhich efficiently transfer the input energy into oscillatory force43that impacts ground42.

Ground pressure detonation device30g,FIG. 14, where like parts have been like numbers, of another embodiment of this invention is similar to ground pressure detonation device30e,FIG. 12. However, in this example, ground pressure detonation device30g,FIG. 14, may use a thrust162from pulse jet160that is high enough so that resonance may not be needed to save energy from one cycle to the next. Device30gis preferably made such that mass162directly impacts ground42with sufficient force to ensure detonation of pressure sensitive explosive devices44in and/or on ground42.

Ground pressure detonation device30h,FIG. 15, where like parts have been given like numbers of another embodiment of this invention preferably includes housing32that includes port200located on the top of housing32and port202located on the bottom of housing32as shown. In this example, oscillation subsystem36is configured as jet engine204configured to provide continuous thrust206. In other designs, thrust206may be supplied from a cylinder having compressed gas therein. Device30halso preferably includes spinning plate208, or similar type device vectoring device, which directs thrust206so it is alternately directed down through port202and up through port200to oscillate housing32, preferably in net oscillating vertical motion210, such that foot34impacts ground42with sufficient oscillatory force43to ensure detonation of one or more pressure sensitive explosive devices44in and/or on the ground42. In one example, housing32oscillates in direction210and foot34remains stationary on ground42. In this example, housing32contacts foot34which impacts ground42with sufficient oscillatory force43. In another example, foot and housing32may bounce up and down off ground42(shown in phantom), indicated by arrow220, and foot34impact ground42with sufficient oscillatory force43. When device30hbounces up and down off ground42, device30hcan be easily advanced preferably while “hopping” over obstacles, such as tree roots, stones, debris, and the like.

Device30hmay also include spring72coupled to foot34as discussed above. The oscillatory force of foot214on ground42and housing32and foot34as they bounce on and off ground42can be tailored by selection of the stiffness of spring212and/or the amount of thrust206and/or the selection of ports200and202. Additionally, spring72and the thrust from ports200and202may be used to create a resonant condition of device30hwhich efficiently transfers the input energy into oscillatory force43that impacts ground42.

The result is ground pressure detonation device30of one or more embodiments of this invention discussed above with reference to one or more ofFIGS. 5-15generates a large, oscillating, vertical force and creates a sufficient force via impact loading with the ground to ensure detonation of pressure sensitive explosive devices in or on the ground. An energy storage spring may create a resonant condition that minimizes power requirements. Device30is relatively small and light weight and is therefore manportable.

In addition to applications for narrow trails and areas where man portability of the device is desired, ground pressure detonation device30of one or more embodiments of this invention can be scaled to greater sizes and/or used in multiple numbers to replace the flails, rollers, and other devices that might be used on roadways and areas wider than small paths. In these applications, ground pressure detonation device30of one or more embodiments of this invention may offer very high ground forces and pressures while weighing far less than conventional flails or rollers that might be used in similar applications. The lower weight of the ground pressure detonation device may provide for easier transport and lower loads and stresses on the vehicles used for guiding and propelling the device.