GB2532295A

GB2532295A - Surface effect unmanned vehicle

Info

Publication number: GB2532295A
Application number: GB1501691.8A
Authority: GB
Inventors: Sewell Gary
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-11-13
Filing date: 2015-02-02
Publication date: 2016-05-18
Also published as: GB201501691D0; GB201420182D0; WO2016075428A1

Abstract

A surface effect vehicle 1 is provided for operating on flat, vertical and curved surfaces. Downforce may be generated by a vortex generator mounted to a plate 4 movably in relation to a chassis 2 via actuators 5,6,7,8. The chassis 2 carries the wheels or wheel equivalent means such as tracks visa outrigger arms 21,22,23. This enables unwanted roll and pitch to be avoided so that the vehicle 1 can remain parallel to a surface. Alternatives to the vortex generator may include a magnetic device, a device employing passive or active pneumatic suckers and a compressor, non contact Bernoulli grip adhesion cups, a device employing induced electro-adhesion means, a device employing microscopic cilia gecko-like means. A wide range of surveillance, inspection and conducting engineering operations are taught. The invention enables the vehicle to operate on vertical surfaces and to perform remote operations.

Description

SURFACE EFFECT UNMANNED VEHICLE

This specification relates to surface effect unmanned vehicles and their applications. Such a vehicle is able to adhere to the surface on which it is operating, whether that surface is horizontal, inclined, vertical or inverted, i.e. a ceiling. It is particularly adapted to moving over curved surfaces of variable radii of curvature, whether concave or convex or flat.

Existing unmanned wall climbing vehicles can have track sides that are not flexible enough to conform to curved surfaces or, if they are fitted with wheels, then the underside of the chassis will bottom out on a convex curved surface. The fixed clearance between the unmanned vehicle chassis and the curved surface on which they are operating therefore presents difficulties to the current generation of unmanned wall climbing vehicles.

When an unmanned wall climbing vehicle fitted with magnetic tracks or wheels attempts to 15 climb a magnetic curved surface its fixed tracks or fixed wheels will only have point contacts, which may not provide enough traction to move the unmanned vehicle on the surface, resulting in a less steerable / controllable unmanned vehicle.

An unmanned wall climbing vehicle fitted with pneumatic suction cups that attempts to 20 operate on a curved surface will not be able to move far on the curved surface as only a few of the plurality of suction cups will make actual contact with the curved surface, resulting in a less steerable / controllable unmanned vehicle.

An unmanned wall climbing vehicle which uses claws to grip onto surfaces that attempts to 25 operate on a curved surface will not be able to move far on the curved surface as only a few of the plurality of claws will make contact with the curved surface, resulting in a less steerable / controllable unmanned vehicle.

An unmanned wall climbing vehicle fitted with electro-adhesion devices that attempts to operate on a curved surface will not be able to move far on the curved surface as only parts of its fixed tracks system or wheel system will make direct contact with the curved surface, resulting in a less steerable / controllable unmanned vehicle.

Vertical take-off and landing (VTOL) unmanned aerial vehicles currently have great difficulty in landing or taking off from non-horizontal and / or curved surfaces as such aerial vehicles lack the surface pressure (adhesion) to remain fixed and stable on non-horizontal and / or curved surfaces. Such unmanned aerial vehicles are currently fitted with fixed wheeled undercarriages but their high centres of gravity means that they topple over and crash if they attempt to land on curved or non-horizontal surfaces or moving surfaces and their fixed undercarriage designs limits their ability to operate on curved or sloping surfaces.

Co-pending patent application No. GB 12 21490.4 teaches the use of a Vortex Generator and its application to a surface effect vehicle and its operation limited to flat surfaces only and with the vortex generator fixed in relation to the surface. Though this vehicle can be adapted to transfer from one flat surface to another at an angled corner, the vortical adhesion is reduced, or can be lost completely, if the surface(s) is(are) not flat as the spacing between it(them) and the vortex generator can become too great. It should be possible to overcome the above difficulties with a vortex generator that is both movable both normally and angularly with respect to a curved surface. Also the wheels, or wheel equivalents, need to be adaptable to conform to the variable curvature of the surface(s). Co-pending patent application No. GB 12 21490.4 teaches none of these additional features.

Surface effect vehicles have many uses, e.g. climbing vertical walls to carry closed circuit television cameras (CCTV) for crowd surveillance, getting aerial views of sporting events, etc., or performing tasks remotely, e.g. changing light bulbs, fixing items in place, etc. However, the surfaces of many buildings have architecturally curved surfaces or features, which restrict the range of travel of surface effect vehicles only to flat surfaces. Also, many industrial surfaces are curved, e.g. aeroplanes, ships, wind turbine blades, etc. and these have to be inspected periodically, e.g. wind turbine blades, which may also be exposed to adverse weather conditions.

Thus there is an urgent need for surface effect vehicles that can operate on curved surfaces of variable radii of curvature.

In this specification, the terms 'downforce' and 'downforce generator' are used to define a force that is created essentially normal to the surface on which the surface effect vehicle is operating and acting directly towards that surface (i.e. holding the vehicle against that surface) and the means of creating that force respectively. Thus as examples, when the vehicle is operating on a horizontal surface, the downforce' will be acting vertically downwards but when the vehicle is operating upside-down on a horizontal ceiling, the 'downforce' will be acting vertically upwards.

According to the invention, there is provided a surface effect vehicle comprising:-i) a downforce generator; ii) a means of supplying power to drive the downforce generator, iii) a plurality of wheels or wheel-equivalent means; iv) a means of mounting the downforce generator in relation to the wheels or wheel equivalent means, said mounting having articulated means of movement in at least the roll, pitch and yaw planes; v) means to monitor the angular relationship between the downforce generator and the surface and to cause the generator to be moved (roll, pitch and I or yaw) in relation to the surface to establish and maintain the angle between the downforce generator and the surface as near normal as practicable; vi) means to move the downforce generator translationally in at least the Z plane (where the Z plane is essentially normal to the plane or to a tangent to the plane of the surface adjacent to the vehicle) i.e. towards and away from the surface; vii) means to monitor the separation distance between the downforce generator and the surface and to cause the generator to be moved (Z plane) in relation to the surface to establish and maintain the optimum separation distance; and viii) means to mount equipment on the vehicle so that it can perform operations; characterised in that the vehicle is powered up and driven on a surface from where it moves via its wheels or wheel equivalent means to a desired location all the time monitoring the separation distance (Z plane) and angular orientation (roll, pitch and / or yaw) between the downforce generator and the surface and maintaining these at the optimum values via the Z plane movement and the articulation means respectively and, when at the desired location, performing the allotted operation(s) using the on-board equipment and thereafter either returning to a predetermined position or to another location to perform another operation(s).

According to a first variation of the invention, the downforce generator is a vortex generator as taught in co-pending patent application No. GB 12 21490.4.

According to a second variation of the invention, the downforce generator is a magnetic device According to a third variation of the invention, the magnetic downforce generator employs variable magnetic field generating or magnetic lifting or permanent magnetic or electromagnetic technology.

According to a fourth variation of the invention, the downforce generator is a device employing passive pneumatic suckers.

According to a fifth variation of the invention, the downforce generator is a device 5 employing active pneumatic suckers.

According to a sixth variation of the invention, the active pneumatic sucker downforce generator includes a compressor or vacuum pump.

According to a seventh variation of the invention, the downforce generator is a device employing Bernoulli grip hollow pads.

According to an eighth variation of the invention, the downforce generator is a device employing induced electro-adhesion means.

According to a ninth variation of the invention, the downforce generator is a device employing microscopic cilia gecko-like means.

According to a tenth variation of the invention, the downforce generator is a device employing forced vortex impellor-like means.

According to an eleventh variation of the invention, the downforce generator is detachably mounted in the surface effect vehicle.

According to a twelfth variation of the invention, the detachable mounting in the surface effect vehicle is a universal mounting into which any type of downforce generator is finable so that downforce generators may be replaced or interchanged as required.

According to a thirteenth variation of the invention, the vehicle incorporates a plurality of 30 downforce generators said plurality including more than one of the same type of generator or a combination of different types of generator.

According to a fourteenth variation of the invention, the power is supplied via an external means.

According to a fifteenth variation of the invention, means are provided to prevent an external power supply cable from entanglement with the vehicle or parts thereof.

According to a sixteenth variation of the invention, the power supply is on-board the surface effect vehicle.

According to a seventeenth variation of the invention, the on-board power supply is a battery.

According to an eighteenth variation of the invention, the on-board power supply is an internal combustion engine or turbine with its own supply of fuel.

According to a nineteenth variation of the invention, the wheels are steerable or omnidirectional (in the X and Y planes) and deployed either singly or in multiple bogie arrangements.

According to a twentieth variation of the invention, the wheel equivalent means are 15 independently-steerable tracked means.

According to a twenty first variation of the invention, the plurality of wheels or wheel equivalent means is at least three, arranged in a stable configuration.

According to a twenty second variation of the invention, the plurality of wheels or wheel equivalent means is one wheel and two independently steerable tracked means.

According to a twenty third variation of the invention, the plurality of wheels or wheel equivalent means is four independently steerable tracked means.

According to a twenty fourth variation of the invention, the plurality of wheels or wheel equivalent means includes flexible mounting either of the bogie(s) or tracked means themselves or within the bogie(s) or tracked means to allow the wheel or wheel equivalent means to conform to the curvature(s) of the surface on which the vehicle is operating.

According to a twenty fifth variation of the invention, the articulated means include linear actuators and flexible joints.

According to a twenty sixth variation of the invention, the articulated means include cam 35 mechanisms.

According to a twenty seventh variation of the invention, the articulated means include hexapod or Stewart Platform type arrangements.

According to a twenty eighth variation of the invention, the means of moving the generator 5 in the Z plane includes a screwed means.

According to a twenty ninth variation of the invention, the means of moving the generator in the Z plane includes a linear actuator.

According to a thirtieth variation of the invention, the means of mounting the generator in relation to the wheels or wheel equivalent means includes a moveable plate or collar.

According to a thirty first variation of the invention, the means to monitor the separation distance and angular orientation between the downforce generator and the surface includes a camera(s) and / or a distance sensor(s) providing input to a controller which compares the input data with reference data in its memory and uses the difference(s) between the two sets of data to generate the required correction(s) and sends a correction signal(s) to the appropriate means to effect corrective action to restore the separation distance and orientation to as near the pre-set optimum values as practicable.

According to a thirty second variation of the invention, appropriate mountings are provided for equipment to be carried on the vehicle and for the operations to be performed.

In a first preferred embodiment a three wheeled, surface effect vehicle, consisting of a single wheel and two tracked means, has the wheel support members connected to a chassis plate, or collar, by articulated means and a detachable and interchangeable downforce generator mounted on a moveable plate. This would allow the generator to be moved in the Z plane relative to the surface and allow the moveable plate / generator assembly to be moved angularly, relative to the surface, by the articulation; thus being able to achieve optimum separation distance and the best angle of orientation.

In a second embodiment, the surface effect vehicle has rotatable, four-blade, fixed pitch rotor vortex generator powered by a motor, which is itself fixed to a moveable plate. A side wall, flexible skirt and the moveable plate are interconnected to the vehicle chassis with actuators that can be independently moved in all 6 planes (x, y, z, roll, pitch and yaw), i.e. lowered, raised or tilted in any plane relative to the vehicle chassis, to enable the vehicle to traverse curved surfaces and pipework. The moveable plate could carry an electric motor, internal combustion engine or gas turbine to drive the rotor. The vehicle may include batteries to power the motor or a fuel tank for the internal combustion engine or gas turbine. Alternatively, the electric motor may be supplied by an external power supply. The moveable downforce generator can be fitted to unmanned vehicles and be used, for example, to increase the slope gradient and radius of curvature from which VTOL aerial vehicles can take-off and land. Other examples are to enable unmanned wall climbing vehicles to operate on more slippery curved and inverted curved surfaces including wind turbine blades, or to increase the stability and mobility of manned and unmanned ground effect vehicles on curved surfaces. Surface crawling, underwater vehicles could operate on curved surfaces such as found on oil platforms, pipelines and submarines. The track sides on the tracked vehicle are also adaptable in multiple planes about the chassis plate, thereby enabling the tracks to conform better to curved surfaces than if they were fast with the chassis, so increasing the track area in contact with a curved surface and thereby increasing overall traction.

In a third embodiment, the surface effect vehicle could include a set of magnets that are fixed to a moveable plate connected to the chassis plate via actuators that can be moved independently in all 6 planes (X, V, Z, roll, pitch and yaw), i.e. the magnets can be lowered, raised or tilted in any plane relative to the vehicle chassis, to enable the vehicle to traverse curved surfaces and pipework. This embodiment can be used to increase the slope gradient and radius of curvature of magnetic surfaces from which VTOL aerial vehicles can land and take-off or to enable vehicles to operate on more slippery, vertical and inverted surfaces, including wind turbine towers. Further applications are to increase the stability and mobility of vehicles on curved magnetic surfaces, such as oil platforms, pipelines and submarines. As before, the track sides on tracked vehicles are adaptable in multiple planes, relative to the chassis plate, enabling the tracks to conform better to curved surfaces thereby increasing overall traction.

In a fourth embodiment, the curved surface operating unmanned vehicle could include any other downforce generation / attraction technology fixed to a moveable plate and interconnected to the vehicle chassis plate via actuators, which as before, can be independently moved in all 6 planes (x, y, z, roll, pitch and yaw) relative to the vehicle chassis plate to enable the vehicle to traverse curved surfaces and pipework. The moveable plate assembly can be fitted to unmanned vehicles and be used in all the ways described above. As before, track sides may be adaptable to increase overall traction.

The surface effect vehicle could use a variety of methods to move its downforce generation / attraction moveable plate, some of which are explained below. All provide both translational and angular displacement.

Firstly, a hexapod or Stewart-type platform style moveable plate could be used. A Stewart-type platform is a parallel kinematic motion device that provides six degrees of freedom: X, Y, Z, roll, pitch and yaw. Hexapods are ingenious and effective solutions to complex motion applications that require high load capacity and accuracy in up to six independent axes. Applications include: optics and satellite assembly and testing, astronomy, biotechnology, surgery, X-ray diffraction, micro-machining, micro-manipulation. A Stewart platform style downforce generating / attraction moveable plate fitted to an unmanned vehicle would enable the downforce generating / attraction moveable plate assembly to be moved quickly in 6 planes, enabling the plate-to-surface clearance to be varied in real-time and optimised to maximise downforce / attraction with the surface it is in closest proximity to and minimise power consumption.

Secondly, multiple cams could be used to interconnect and actuate the downforce generating / attraction moveable plate to the unmanned vehicle chassis.

Thirdly, multiple linear actuators could be used to interconnect and actuate the downforce generating / attraction moveable plate to the unmanned vehicle chassis.

Fourthly, multiple pneumatic bags, or piston/cylinders, could be used to interconnect and actuate the downforce generating / attraction moveable plate to the unmanned vehicle chassis.

Fifthly, a threaded collar, or bars with keylocks, could be used to interconnect and move the downforce generating / attraction moveable plate about the unmanned vehicle chassis.

Sixthly, a swashplate mechanism could be used to interconnect and move the downforce generating / attraction moveable plate about the unmanned vehicle chassis.

Seventhly, multiple limbs interconnecting the downforce generating / attraction moveable plate to its tracks or wheels could be used to move the plate relative to the surface against which it is operating.

For a clearer understanding of the invention and to show how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings in which:-Figure 1 shows a curved surface operating unmanned vehicle; Figure 2 shows a linear actuator actuated moveable plate; Figure 3 shows a cam actuated moveable plate; Figure 4 shows a hexapod platform, linear actuator actuated moveable plate; Figure 5 shows a threaded collar or bar actuated moveable plate; Figure 6 shows a 4-bladed vortex downforce generator variable surface pressure device mounted on a moveable plate; Figure 7 shows a variable magnetic field generating magnetic lifter mounted on a moveable plate; Figure 8 shows three moveable plates mounted on a hinged chassis plate; Figure 9 shows a tri-limbed unmanned vehicle fitted with omni-directional wheels; Figures 10A, 10B, 10C shows three views of the unmanned vehicle from Figure 1, fitted with the threaded collar actuated moveable plate from Figure 5, operating on vertical convex, vertical flat and vertical concave surfaces; Figure 11 shows an unmanned vehicle fitted with 4 articulated track units and a central moveable / rotatable plate; Figure 12 shows two unmanned vehicles from Figure 11 mounted in a double-decker style arrangement and inter-connected with articulated powered arms to produce an articulated unmanned vehicle; Figure 13 shows double-decker style, articulated unmanned vehicles from Figure 12 on an obstacle course; Figure 14 shows an unmanned ground vehicle operating on a curved surface that has been fitted with articulated tracks and a moveable plate and a crane arm lifting an object; Figure 15 shows the unmanned vehicle from Figure 10A scanning a curved reinforced concrete structure with a rebar detector; Figure 16 shows the unmanned vehicle from Figure 10A inspecting the exterior and interior surfaces of a wind turbine blade with cameras, ultrasonic sensors and installing vortex generators to the exterior surface; Figure 17 shows the unmanned vehicle from Figure 10A fitted to a VTOL unmanned aerial vehicle (UAV) operating on an inverted curved surface; Figure 18 shows the unmanned vehicle from Figure 10A fitted to an unmanned underwater vehicle (UUV) operating on a curved underwater structure; Figure 19 shows multiple unmanned vehicles from Figure 11 mounted on a helicopter operating on a curved submarine hull at sea and lifting a cylindrical object; Figure 20 shows a manned crane remotely lifting an unmanned vehicle from Figure 11 that is remotely lifting and manoeuvring in mid-air a cylindrical object.

In the following description, the same reference numeral is used for the same component in different Figures and / or for different components fulfilling identical functions.

Fig. 1 shows a surface effect vehicle 1 which has a chassis 2 with chassis aperture 3 inter-connected to a moveable downforce generator mounting plate 4 by moveable actuators 5, 6, 7, 8. (As shown, all the surface effect vehicles 1 in this disclosure are unmanned and will thus be provided with sensors and communication means to interface with a remotely-located operator. This aspect of the design will be understood by the skilled person and, to avoid confusing detail, this sensing and communication equipment is not shown in the Figures.) At the ends of each of the moveable actuators 5, 6, 7, 8 are joints 9, 10, 11, 12, 13, 14, 15, 16 that allow plate 4 to be moved in multiple planes relative to the vehicle chassis 2. Proximity sensors or cameras 17, 18, 19, 20 are mounted essentially equidistantly on the periphery of plate 4.

Three outrigger arms 21, 22, 23 are attached securely to and positioned equidistantly around the chassis 2 and plate 4. At the ends of two of the outrigger arms 21, 22 are attached articulated joints or inter-connectors 24, 25. Track support plates 27, 28 are attached to the articulated joints or inter-connectors 24, 25. At one end of the track support plates 27, 28 are return sprocket holding blocks 31, 33 that are attached to return sprockets 35, 38.

At the other end of the track support plates 27, 28 are drive sprocket motors 32, 34 that are connected to drive sprockets 36, 37. Tracks 43, 44 pass round the drive sprockets 36, 37, return sprockets 35, 38 and flexible track pads 41, 42, which lie between the underside of the track support plates 27, 28 and the tracks 43, 44. The flexible track pads 41, 42 should be detachable from the track support plates 27, 28 so that new flexible tracks pads 41,42 can replace worn out flexible track pads 41, 42. The flexible track pads 41, 42 could be bonded to the track support plates 27, 28 using double-sided foam that would enable the flexible track pads 41, 42 to comply better with undulating and curved surfaces against which the vehicle tracks 43, 44 were operating.

The articulated joints or inter-connectors 24, 25 enable track support plates 27, 28 and their tracks 43, 44 to conform to curved surfaces better than if they were fixed to the chassis 2, so increasing the track 43, 44 areas in contact with a curved surface and thereby increasing overall traction of the tracks 43, 44. In order to conform to curved surfaces vehicle 1 is shown with a third outrigger arm 23 that has a support arm 26 with a flexible joint or interconnector 29 at its end, to allow wheeled unit support plate 30 to rotate through 360 degrees and pivot in all planes like a castor-wheeled unit. High traction wheels 39, 40 are interconnected with the wheeled unit support plate 30.

To increase traction, more than two high traction wheels 39, 40 could be fitted to the wheeled unit support plate 30. It should be noted that the two powered tracks 43, 44 and the wheels 39, 40 combine to act like a tripod and its triangular formation contact with a surface ensures that the articulated wheels 39, 40 and articulated tracks 43, 44 are in continuous contact with irregular and complex curved surfaces, whilst conferring exceptional manoeuvrability to the unmanned vehicle 1 on irregular and complex curved surfaces.

Vehicle chassis 2 (Fig. 1) has 3 outriggers 21, 22, 23 to give a stable, tripod platform, but a variable number of outriggers could be attached to the vehicle chassis. The unpowered wheels 39, 40 could be replaced with a third powered / unpowered articulated tracked unit. The combination of two powered track drive units and a third wheeled unit ensures that vehicle 1 conforms to the curved / irregular surface against which it is operating whilst ensuring maximum traction and permits neutral steering / on-the-spot 360° rotation, like a tank, as well as other complex precision manoeuvres that its operator instructs it to do in confined spaces or on other complex shaped structures ranging from aircraft fuselages, wind turbine blades and pipelines.

Rather than having 2 powered track units and a wheeled unit, vehicle 1 could use 3 powered omni-directional Mecanum® wheels, like those shown in Fig. 9, which would 30 enable it even to move sideways.

The vehicle shown in Fig. 1 is designed to manoeuvre in any direction on a curved/irregular surface, so power cable management is very important to prevent its power cable 47 from becoming entangled by its tracks 43, 44 or its wheels 39, 40. Fig. 1 shows vehicle 1 with a cable management support arm 45 that can rotate through 360° on outrigger 23 to which it is attached.

Rotatable cable management support arm 45 could be attached to either of the other 2 outriggers 21, 22 or to the chassis 2. A strain relief sock 46 covers the power cable 47 to the cable management support arm and ensures that a length of the power cable 47 could support the entire weight of the unmanned vehicle 1. If a strain relief sock 46 was not used then it would be possible for the connector at the end of the power cable 47 to momentarily support the unmanned vehicle 1 before the connector came loose or broke off the unmanned vehicle. The power cable should preferably be spooled loosely to the vehicle and ideally a safety line 48 should also be attached to the rotatable cable management support arm 45.

The safety line 48 and not the power cable 47 should be used to support vehicle 1 in the event that it 1 comes away from the surface on which it is moving. Cable 46 and safety line 48 should also always be kept as taut as practicable so that the vehicle does not fall or, in the event that it does lose grip with the surface on which it is moving, does not damage either the surface or the vehicle 1.

Fig. 2 shows moveable mounting plate 4 connected to linear actuators 5,6,7,8 which have flexible joints 9, 10, 11, 12, 13, 14, 15, 16 at their ends. This enables mounting plate 4 to be moved in 4 planes (roll, pitch, yaw and Z) about the vehicle aperture 3 and chassis 2.

(In this description, the Z plane is taken to be normal to the plane, or to a tangent to the plane, of the surface on which the vehicle 1 is adjacent.) The vehicle chassis is attached to the flexible joints 9, 11, 14, 16, and the powered linear actuators 5, 6, 7, 8 can vary the clearance distance and angle between the plate 4 and the proximate surface, i.e. the surface closest to the downforce generator. Proximity sensors or cameras 17, 18, 19, 20 are mounted essentially equidistantly on the periphery of plate 4 and, via a controller (not shown), provide real-time feedback information to actuators 5, 6, 7, 8 to ensure that plate 4 is at the optimum separation distance and angle to the curved / irregular, proximate surface.

Fig. 3 shows a cam-actuated moveable plate 4 which is connected to flexible joints 10, 12, 13, 15 attached to support blocks 49, 50, 51, and 52 respectively. Cams 57, 58, 59, 60 are rotatable by motors 53, 54, 55, 56, respectively, and as they rotate, cams 57, 58, 59, 60 produce lateral movement of sliders 61, 62, 63, 64 in the channels in the support blocks 49, 50, 51, 52, respectively. Flexible joints 9, 11, 14, 16 are attached to the sliders 61, 62, 63, 64 and these flexible joints 9, 11, 14, 16 can be attached to vehicle chassis 2. The flexibly jointed, cam actuation allows the moveable plate 4 to be moved in 4 planes (roll, pitch, yaw and z) about the vehicle aperture 3 and vehicle chassis 2, thereby varying the clearance distance and angle between the plate 4 and the proximate surface.

As taught above, proximity sensors or cameras 17, 18, 19, 20 provide real-time feedback information, via a controller (not shown), to the 4 cam actuator units to ensure that plate 4 is at the optimum separation distance and angle to the curved / irregular proximate surface.

Proximity sensors or cameras 17, 18, 19, 20 do not act individually but combine to give an appreciation of the topography of the surface to which surface effect vehicle 1 is adhering.

This will mean that the positioning of downforce generator 98 (Fig. 6) is determined by the overall topography rather than an unrepresentative feature, e.g. a single groove running across a flat surface. It will also be noted that single or bogied wheels 39, 40 are less able to pass over some obstructions, e.g. grooves, than tracked means 43, 44 (Fig. 1) so that 4 tracked vehicles (Fig. 11) are better suited to rough surfaces.

Fig. 4 shows a hexapod or Stewart-type platform actuated plate 4. Three pairs of closely spaced flexible joints 71, 72 & 73, 74 and 75, 76 & 77, 78 and 79, 80 & 81, 82 re-positioned at 120° to each other around the periphery of plate 4. Six moveable linear actuators 65, 66, 67, 68, 69, 70 have flexible joints 71, 74, 75, 78, 79, 82, respectively, at their ends and are attached (not shown) to vehicle chassis 2 again in three pairs at 120° to each other. As taught above, proximity sensors or cameras 17, 18, 19, 20 provide real-time feedback information to the six linear actuators 65, 66, 67, 68, 69, 70, to ensure that plate 4 was at the optimum separation distance and angle to the adjacent curved / irregular, proximate surface.

The hexapod or Stewart platform arrangement (Fig. 4) of 6 linear actuators 65, 66, 67, 68, 69, 70 and their flexible joints 71, 72 & 73, 74 and 75, 76 & 77, 78 and 79, 80 & 81, 82 allows plate 4 to be moved in all 6 planes, (roll, pitch, yaw, X, Y and Z) about the vehicle chassis aperture 3 and chassis 2. Whilst the control software required for the six actuators and the four proximity sensors or cameras 17, 18, 19, 20 in a hexapod configuration is more complex than that required for the 4 actuators shown in Fig. 2 and Fig 3, the potential advantages of such a configuration are considerable as the spatial relationship between plate 4 and the curved / irregular, proximate surface can be more precisely controlled than any other known system. The proximity or camera sensors 17, 18, 19, 20, mounted around the periphery of plate 4, the hexapod configuration and appropriate computer control allow the most precise contour mapping of the adjacent surface and best terrain following than that of any other known system, thereby maximising downforce attraction and minimising energy consumption whilst allowing plate 4 to move over the surface and clear any obstacles / voids on it in real-time. It also minimises losses from the around the edges of the downforce generator.

The scale-able 6-axis, hexapod configuration platform shown in Fig. 4 has wide application, e.g. in flight simulators, machine tool technology, satellite dish positioning, telescope alignment and orthopaedic surgery, etc. Because motion is produced by a combination of movements of several of the 6 actuators, such a device is sometimes called a synergistic motion platform, due to the mutual interactions of the multiple actuators as they are integrated together via the controller's program, using the inputs from the four proximity sensors or cameras 17, 18, 19, 20. Any suitable linear actuator may be used in this application, e.g. pneumatic or hydraulic devices.

Fig. 5 shows a threaded collar or bar actuated moveable plate 4. Mounted on the vehicle chassis 2 and in the chassis aperture 3 is a mounting block 83 that can be fixed in the aperture 3. Mounting block 83 has within it a drive sprocket 89 that sits between thrust bearings 90, 91 and there is a cover, mounting block 84. Motor 88 is mounted on the side of the mounting block 83 within its own two piece protective casing 85, 86. Motor 88 is connected to drive sprocket 87 meshing with drive sprocket 89. The inside face of drive sprocket 89 is also toothed and engages threaded collar 92 so rotation of motor 88 drives threaded collar 92 up and down in one plane as motor 88 is powered in either direction. (In this description, the plane of motion of collar 92 is defined as the Z plane, i.e. essentially normal to the adjacent surface on which vehicle 1 is operating, or a tangent to that adjacent surface.) The bottom end of the threaded collar 92 is attached to plate 4 by a collar 95.

The drive sprockets 87, 89 rotate but a guide channel 94 in the threaded collar 92 mates with a stationary mounting block 93 that can be mounted on the plate 4.

Stationary mounting block 93 prevents threaded collar 92 and the plate 4 from rotating; they only move up and down in the one plane towards and away from the adjacent surface. It should be noted that the threaded collar 92 mechanism (Fig. 5) produces movement of plate 4 in only one-axis, the Z axis, i.e. moving the plate 4 closer to, or farther away from, the adjacent surface. For many robotic applications this one-axis of movement of the plate 4 may be satisfactory as it minimises component complexity and production costs. When mounted on a tripod-like unmanned platform, like vehicle 1 (Fig. 1), that is self-levelling in nature, e.g. via the 3 outrigger arms 21, 22, 23, the one-axis plate 4 moving mechanism, shown in Fig. 5, may be adequate for volume produced crawling vehicles operating on simply curved surfaces.

Again, multiple mini-cameras or proximity sensors 17, 18, 19, 20 could be mounted about the periphery of plate 4, so that the plate 4 to surface clearance can be determined and varied in real-time electronically or remotely by its human operator. Different variable surface pressure / downforce generating / attraction devices, technologies, tools can be fitted to the moveable plate 4, and three 3 examples follow.

Fig. 6 shows a 4-bladed vortex downforce generator variable surface pressure device 98 mounted on the moveable plate 4, according to the teaching of UK co-pending patent application No. GB 12 21490.4. A circular side wall 99 extends from the underside of the mounting plate 4 and together, they create a partially enclosed volume. Flexible skirt 100, attached to the side wall 99, extends below the base of the side wall 99. A power-plant 96 is attached to the centre of the top surface of the mounting plate 4 and provides the drive to rotate shaft 97, which rotates the fixed four-blade rotor 98. There is an air-tight seal between the side wall 99, its flexible skirt 100 and the mounting plate 4. There is also an airtight seal between the base of the power-plant 96 and the mounting plate 4. There is a clearance gap between the drive-shaft 97 and the mounting plate 4.

The design of rotor 98 used can be varied to vary and maximise the pressure differential that the rapidly-rotating rotor 98 generates, with a low pressure region being created between the plate 4 and the surface against which it is operating and the relatively higher ambient fluid pressure acting against the top side of the plate 4. This pressure differential presses the unmanned vehicle 1 against the surface. Again, multiple mini-cameras or proximity sensors 17,18,19,20 could be mounted about the periphery of plate 4, so that the plate 4 to surface distance can be measured in real-time and the data used either automatically or remotely by its human operator. The flexible joints 10, 12, 13, 15 could also be mounted around the periphery of the plate 4, as shown in Fig. 6.

Permanent magnetic lifters are widely used in industry for lifting and transporting ferrous objects and one or more permanent magnetic lifters 101 (Fig. 7) could be mounted within or on the plate 4 so that its underside is flush 102 with the underside of plate 4 or located at a certain distance relative to plate 4. Alternatively, magnetic lifter 101 could be placed on top of plate 4 if top plate 4 was made from a non-magnetic material. Flexible joints 10, 12, 13, 15 could also be mounted around the periphery of the plate 4, as shown. Permanent magnetic lifter 101 has blocks of high-energy magnetic material within it and switching the magnetic lifter on and off is achieved by reversing the polarity of one its intemal magnetic blocks. In the "on" position, the reversible block is in parallel with the static blocks so that a concentrated magnetic field is produced at the pole feet, or underside face of the magnetic lifter device, for lifting. In the "off' position, the reversible block is rotated through 180° to provide a total magnetic short circuit within the lifter body.

The reversible block within the magnetic lifter is connected to a handle 103. The reversible block can be rotated anywhere in 180° to produce variable magnetic attraction. Servo 106 is mounted on the plate 4 and is connected by bars 105, 104 to the handle 103; motion of servo 106 causes magnetic lifter 101 to move between 'on', 'off' or intermediate positions. Alternatively, the permanent magnet lifter 101 could be positioned elsewhere on vehicle chassis 2, including in the track plates 27, 28 so that the permanent magnet lifters could act through tracks 43,44 and thereby increase the traction against any ferrous surface on which vehicle 1 was driving. As before, multiple mini-cameras or proximity sensors 17, 18, 19, 20 provide separation distance data for controlling vehicle 1.

The magnetic lifter 101 attraction to any ferrous material or ferrous surface will decrease as the distance between the surface and lifter 101 increases so the mini-cameras or proximity sensors 17, 18, 19, 20 can be used to vary the separation distance and hence magnetic attraction to any ferrous surface. A vehicle 1, fitted with a moveable plate 4 and magnetic lifter 101, will therefore be able to move freely and silently over ferrous surfaces. The operator of vehicle 1 can vary the magnetic attraction force with a ferrous surface and thereby vary the amount of payload that vehicle 1 can carry.

The operator can also stop vehicle 1 at any position on a ferrous surface and lower the moveable plate 4 so that magnetic lifter 101 is in direct contact with the surface, resulting in maximum magnetic attraction, enabling the stationary vehicle 1 to perch silently for extended periods and so save power. If the human operator wants to drive the vehicle elsewhere on the ferrous surface, servo 106 would be actuated 104, 105 to reduce the magnetic attraction slightly by lifting moveable plate 4 clear of the surface (i.e. to an intermediate position).

Multiple downforce generating I attraction technologies or devices or tools could be fitted to a single vehicle 1. For example, Fig. 8 shows a vehicle chassis plate 2 fitted with three linear actuated moveable plates 4A and 4B and 4C. Linear actuators 5A, 6A, 7A, 13A and 5B, 6B, 7B, 8B and 5C, 6C, 7C, 8C can be used to move the moveable plates 4A, 4B and 4C in 4 planes (roll, pitch, yaw and Z) relative to the chassis 2 and the adjacent surfaces.

Alternative actuation devices could be used as described in Figs. 3, 4 and 5.

Multiple downforce generating / attraction technologies or devices fitted on one vehicle chassis 2 could have several advantages, including an ability to increase the mission endurance of a battery powered vehicle 1, as longer endurance silent inspection missions on ferrous metallic objects like ships and wind turbine towers could be performed if only the permanent magnet lifter fitted to, say, plate 4A was activated. A forced vortex downforce generator fitted to, say, plate 4B could selectively be powered when operating on nonferrous surfaces or where there is a transition from ferrous to non-ferrous structures, like on a ship that may have a ferrous hull and a composite superstructure or a wind turbine that has a ferrous metal tower and composite non-magnetic nacelle and blades.

Multiple moveable downforce generating / attraction technologies fitted to plates 4A, 4B, 4C could therefore be employed on the same vehicle chassis 2 to enhance the overall capabilities of a vehicle 1. Alternatively, multiple downforce generators / attraction technologies fitted to plates 4A, 4B, 4C would permit two downforce generator / attraction device fitted to, say, plates 4A, 4B to produce downforce for the vehicle chassis 2 when used on curved surfaces whilst a third device fitted to plate 4C could be used to lift and transport different objects to another location, in effect a single vehicle 1 could be used for material handling purposes without requiring complicated end effect grippers.

Having multiple moveable plates 4A, 4B, 40 could also enhance the redundancy of the unmanned vehicle 1 as multiple downforce generators / attraction devices of the same, or different, types could be used in the event that any one of them failed or failed to produce enough downforce safely to keep vehicle 1 against a surface on which it was operating. Any known or future downforce generating / attraction device technology could be fitted to plates 4A, 4B, 4C, including magnetic lifters 101, forced vortex devices (like those shown in Fig. 6), as well as pneumatic suckers, electro-adhesion devices or microscopic cilia gecko-like material. The plates 4A, 4B and 4C could also be arranged in different ways instead of the three plate triangular formation shown in Fig. 8, either in series or in parallel, enabling greater payloads or batteries to be carried on the vehicle chassis 2, for example. Fig. 8 also shows a centrally mounted device 107 that could be either another moveable downforce / attraction means or a moveable tool, such as a drill, laser head, or a sensor, such as camera; in fact, device 107 could be anything that the vehicle 1 is able to carry and tit on its chassis 2.

The vehicle chassis itself could be articulated instead of being a single unit. Fig. 8 shows such an articulated chassis plate 2 with a hinge 108 that connects the chassis plate 2A (having moveable plates 4A, 4B) with the other chassis plate 2B (having moveable plate 4C). Chassis plates 2A and 2B could be articulated, e.g. via a servo 109 attached to plate 2A and connected by an arm 111 to a mounting block 110 on chassis plate 2B. An articulated chassis plate 2A, 2B could have several advantages over a fixed, single chassis plate 2. For example, the two articulated chassis plates 2A, 2B could conform better to a curved / irregular surface than a fixed single chassis plate 2. An articulated, snake-like chassis composed of multiple inter-connected chassis plates would also be possible, enabling a vehicle 1 to conform and 'wrap around' poles / cylinders of varying diameters; this would further enhance the radii of curvature on which vehicles 1 fitted with moveable downforce generating / attraction devices could operate.

Several embodiments of unmanned vehicles are now considered.

Fig. 9 shows a moveable downforce generator mounting plate 4 which has 3 powered limbs 118, 119, 120 and 3 omni-directional wheels 130, 131, 132. The mounting plate 4 has three equi-distantly spaced, powered limbs 118,119,120 and proximity sensors or cameras 112, 113, 114 mounted around its periphery. Powered joints 115, 116, 117 are each attached to limbs 118,119,120 and at the end of each limb 118,119,120 are further powered joints 121,122,123. Brackets 124, 125, 126 interconnect the powered joints 121, 122, 123 with motors 127, 128, 129. Omni-directional wheels 130, 131, 132 are attached to the motors 127, 128, 129, each of which can be powered independently.

Mecanum® omni-directional wheels 130, 131, 132 are preferred but conventional wheels or tracks could equally well be used. The use of 3 omni-directional wheels 130,131,132 enables the unmanned vehicle shown in Fig. 9 to move on curved surfaces in any direction without having to steer the vehicle's moveable plate 4 in any particular direction. Mounting plate 4 can also be moved in multiple planes relative to the curved surface it is operating against by independently actuating the 3 limbs 118,119,120 and their powered joints 115, 116, 117, 121, 122, 123. This vehicle design (Fig. 9) eliminates the need for a separate vehicle chassis 2. The three proximity sensors or cameras 112, 113, 114 could be used in conjunction with the powered joints 115, 116, 117, 121, 122, 123 to move the limbs 118, 119, 120 and central plate 4 in real-time so varying the plate 4 to surface distance in real-time as it traverses over curved or irregular surfaces.

Figures 10A, 10B, 10C show 3 side views of a vehicle 1, first described in Fig. 1, and the 35 threaded collar 92 actuator method of Fig. 5.

Fig. 10A shows vehicle 1 operating on a convex curved surface 133. The central mounting plate 4, with its threaded collar 92, is in a fully retracted position. Four proximity sensors or cameras 18, 19, 20 (only three shown) are mounted on the periphery of moveable plate 4 ensuring that the plate 4 to surface 133 separation gap 136 can be maintained at the optimum distance either automatically or remotely by its human operator in real-time, thus ensuring maximum downforce whilst conforming to the profile of surface 133. Articulated unit 25 and the support arm 26 ensure that the track 34 and wheels 39, 40 conforms to the curved convex surface at all times to maximise traction with the surface 133. The power cable and safety line management arm 45 exceeds the height of the threaded collar 92 and ensures that the power cable and safety line are always kept away from vehicle 1.

Fig. 10B shows the vehicle described in Fig. 10A operating on a flat surface 134. Mounting plate 4 is shown with its threaded collar 92 in an intermediate position and all other items are as described for Fig. 10A to conform to flat surface 134 and so maximise traction.

Fig. 10C shows the vehicle described in Fig. 10A operating on a concave curved surface 135. The centrally mounted moveable mounting plate 4, with its threaded collar 92, is in a fully extended position and all other items are as described for Fig. 10A to conform to concave surface 135 and so maximise traction. The tripod-like, self-levelling characteristic of vehicle 1 (Figs. 10) ensures that the moveable plate 4 will always be essentially parallel to the surface against which it is operating, so that the powered threaded collar 92 method of moving plate 4 (moving in the Z plane) can ensure the optimum clearance gap 136 to maximise the downforce.

Fig. 11 shows another vehicle 137 design that has a moveable plate 4 that can also be rotated 360° thanks to two pins 138A, 138B that inter-connect the chassis 2 with a circular plate 139. Either or both of the pins 138A, 138B can be powered and rotated and their pin drive motors could be housed in payload modules 142, 144. The gap between the plate aperture 3 of the chassis 2 and the circular plate 139 would need to be big enough and the pins 138A, 138B long enough to allow the circular plate 139 to rotate within aperture 3.

The circular plate 139 has cut-out connector arms 140 to reduce weight and a threaded collar 92 actuation method (Fig. 5) is employed on the vehicle 137. The threaded collar 92 is powered by a motor that is contained within a two part cover 85, 86 and two part cover 83, 84 over the sprocket that moves the threaded collar 92 up and down. The vehicle 137 is battery powered and has 4 payload modules 141, 142, 143, 144 which can hold batteries or other items.

Vehicle 137 is battery powered and designed to negotiate complex obstacles which would make power cable and safety cable management extremely difficult: they would also limit the distance that the unmanned vehicle 137 could travel before the weight of the power cable and safety line would impact on its mobility. Attached equi-distantly around the circular chassis 2 are four motorised joints 145, 146, 147, 148 and these are attached to moveable limbs 149, 150, 151, 152. At the other end of each limb 149, 150, 151, 152 are motorised joints 153, 154, 155, 156 that can also rotate about the track support units 157, 158, 159, and 160. Track support units 157, 158, 159, 160 have track pad plates 161, 162, 163, 164, 165, 166, 167, 168 with a sandwich construction of a metal plate, foam inner layer and a low friction surface to reduce friction with the four tracks 181, 182, 183, 184 against which they press. Drive sprocket motors 169, 170, 171, 172 are connected to the outer ends of the track support units 157, 158, 159, 160 and the drive sprocket motors 169, 170, 171, 172 are connected to drive sprockets 173, 174, 177, 178.

Unpowered, free-running return sprockets 175, 176, 179, 180 are provided at the outer ends of the track support units 157, 158, 159, 160. The four drive sprockets 173, 174, 177, 178 move the four high traction tracks 181, 182, 183, 184 independently. Plate 4 is interconnected with the threaded collar 92 by a connecting ring 95 and one of four proximity sensors or cameras 185 is shown fitted to the periphery of the moveable plate 4.

Whilst this design of vehicle 137 does not have the tripod, self-levelling characteristic of vehicle 1 (Fig. 1 and Figs. 10), it does offer increased traction with the surface via four tracks 181, 182, 183, 184. The powered jointed limbs 149, 150, 151, 152 and the rotating powered joints 153, 154, 155, 156 are used to ensure that the four tracks 181, 182, 183, 184 always make full contact with the surface, no matter how irregular it may be, in effect acting like active suspension systems.

Proximity sensors or cameras 185 are used to ensure that the moveable plate 4 is always at the optimum distance from the proximate surface. Also, via pressure sensors in the track pad plates 161, 162, 163, 164, 165, 166, 167, 168 of each of the four articulating track units 157, 158, 159, 160, the loading on each track unit can be balanced to optimise the active capabilities of the suspension. Suspension control may be automatic via a computer or from its human operator.

The combination of four articulated track drive units, four powered limbs 149, 150, 151, 152 and a rotatable central moveable plate 4 would give this vehicle 137 several unique operating characteristics including an ability to flip over and still generate downforce / attraction with the closest surface, i.e.in effect the vehicle 137 does not have a bottom or top side. The variable ground clearance and its moveable plate 4 enable vehicle 137 to increase its surface to plate 4 separation gap when traversing rough terrain or when approaching an obstacle in its path. Articulated limbs 149, 150, 151, 152 would be at the lowest optimal setting to minimise peeling action if vehicle 137 was ascending a vertical surface. Omni-directional wheels could be used instead of driven track drive units.

Fig. 12 is a side view of an active articulated vehicle 186 design formed from two of the Fig. 11 vehicles 137A, 137B, stacked back-to-back in a double decker style arrangement. Attached to the end of the payload module 143A on vehicle 137A is a powered articulation means consisting of joint 190, first arm 191, joint 192, second arm 193 and joint 194 attached to the end of the payload module 141B. Vehicle 186 has shown two moveable plates 4A, 4B facing away from each other, and each is rotatable through 360°, as taught above and shown in Fig. 11. The moveable plates 4A, 4B can be used with any downforce generator technology but, in Fig. 12, vortex air generators 189A, 189B are used as taught above and shown in Fig. 6.

Variable gap 188A is shown between vortex generator 189A and surface 187A, i.e. only half of vehicle 186 is in contact with a surface but it is equally possible for vehicle 186 to operate with gap 188B between generator 189B against another surface (not shown).

Plates 4A, 4B are moveable by powered threaded collars 92A, 92B, as taught (Figs. 5, 11).

Vehicle 186 has several beneficial design features and extraordinary mobility capabilities, which are illustrated in Fig. 13. This shows stacked vehicle 186 negotiating an obstacle course 195. The difficult manoeuvres and obstacles included in obstacle course 195 cannot presently be accomplished by any known single unmanned vehicle design. Vehicle 186 however is designed to accomplish all of the manoeuvres and negotiate all the obstacles of the obstacle course 195.

Stacked vehicle 186A starts obstacle course 195 with vehicle half 137A moving on an uneven rough surface 195A and its vortex attractor 189A and plate 4A is elevated away from surface 195A producing a large gap 188A ensuring that the vortex generator is clear of and not damaged by the rough uneven surface 195A. When vehicle 186A approaches horizontal to vertical, 90° comer transition 195B, vehicle half 137A stops and other half vehicle 137B is elevated up and around until it is resting against the vertical surface 195C thanks to powered articulated jointed arms 190, 191, 192, 193, 194. The result is vehicle 1868 with one half 137A on horizontal rough surface 195A and its other half 137B on vertical surface 195C. Downforce generator 189B is then moved to an optimum distance 188B against the surface 195C and downforce generator 189B started to produce enough downforce to hold the entire unmanned vehicle 1868. Generator 189A is switched off and powered articulated jointed arms 190, 191, 192, 193, 194 lift vehicle half 137A off the rough uneven surface 195A and stack it (Fig. 12) against the active vehicle half 137B.

To ensure that the powered articulated jointed arms 190, 191, 192, 193, 194 can always be extended in the same direction as that in which vehicle 186 is moving in, vehicle 186B needs to be rotated through 180°, as indicated by symbol 186C.

When stacked vehicle 186 encounters a vertical surface mounted protruding obstacle 195D, e.g. a cable tray or pipe, the powered articulated jointed arms 190, 191, 192, 193, 194 are used to lift vehicle half 137A over and across obstacle 195D back onto the vertical surface 195C where its downforce generator 189A would be lowered and powered up. The separation gap 188A would be optimised to generate the maximum amount of downforce against surface 195C. Generator 1896 is then deactivated, moved away from the surface 195C and powered articulated jointed arms 190, 191, 192, 193, 194 used to lift vehicle half 137B over and across obstacle 195D and stack it on top of the other vehicle half 137A. As before, stacked vehicle is rotated 186E.

Vehicle 186E now approaches inverted, corner transition 195E and vehicle half 137A stops. Half vehicle 1378 is unstacked by the articulated arms and placed against surface 195F. Now vehicle 186F has one half 137A adhering to vertical surface 195C and its other half 1376 touching inverted, convex, curved surface 195F. Downforce generator 189B is moved towards surface 195F and generator 189B is switched on. Generator 189B is switched on and proximity sensors or cameras (20 on the edges of plate 4, Figs. 10) ensure the optimum downforce is generated 189B and that the tracks conform to surface 195F. Generator 189A is then deactivated and the articulated arms lift vehicle half 137A off the vertical surface 195C and stack it against vehicle half 137B. Generator 1898 has enough downforce to hold both unmanned vehicle halves 137A, 137B against surface 195F.

Many current generation wall climbing vehicles could not make the 186F transition from vertical to inverted surfaces without assistance, but vehicle 186 is designed to accomplish it unaided.

Vehicle 186 is now rotated through 180° 186G and driven to the end 195H of the shelf.

Another beneficial design feature of this stackable vehicle 186 arrangement is that its length-to-width ratio of either half 137A, 137B or as stacked vehicle 186 is close to unity, permitting the stacked vehicle 186 to perform neutral steering / on-the spot rotations and other precise manoeuvres, which could not be as easily accomplished if the two halves of the vehicle 137A, 137B were in the end-to-end configuration with a length-to-width ratio being over 2. Additionally, only one downforce generator, either 189A, 1898 needs to be active when vehicle halves 137A, 137B are stacked and the articulated arms are in their fully collapsed position, thereby increasing the vehicle's 186 mission endurance, if battery powered. When the articulated arms are fully folded, the stacked 186 vehicle's overall height is minimised; this also minimises the height of its centre-of-gravity which is a critical factor in vehicle stability (i.e. minimising overturning moments and peeling action) while only one of the two downforce generators 189A, 189B is active and supporting the entire vehicle's 186 weight. This is an important design criterion.

At the end of shelf 195H, the articulated arms lift top vehicle half 137A from its stacked position, around the shelf 195H and onto the inverted horizontal surface 1951 where its downforce generator 189A would be powered up, and moved to the optimal separation gap 188A, via cameras or proximity sensors, to generate the maximum amount of downforce against surface 1951. Generator 189B is deactivated and the articulated arms used to lift vehicle half 137A off horizontal flat surface 195G, around the shelf 195H and stack it on the other half 137A. It will be noted that half 137B can be moved in such a way as to minimise overturning and peeling forces on half 137A and thus reduce the risk of half 137A losing adhesion to surface 1951.

Vehicle 186 is tumed through 180° 1861 and driven 1951 to and round curve 195J, with its generator clearance 189A adjusted and its tracks conforming to the concave curve, and on and over lip 195K onto flat surface 195L.

Vehicle 186J now approaches external 270° corner 195M. Generator 189A holds half vehicle 137A steady while the articulated arms unstacks half 137B and places it against surface 195N. Generator 189B is started and adjustments are made to hold it firmly against surface 195N. When it is secure, generator 189A is switched off and the articulated arms move half 137A back to the stacked position. (As before, this movement is done in a way to minimise overturning and peeling moments.) Vehicle 186 is turned 186L.

At gap 1950 in the vertical surface 195N, articulated arms unstack vehicle half 137A, move it over and across the gap 1950 and back onto the vertical surface 195N where its downforce generator 189A would be lowered and activated, the separation gap 188A would be optimised to generate the maximum amount of downforce against surface 195N. The downforce generator 189B would then be deactivated and half 137B would be lifted away from the surface 195N and across the gap 1950 by the articulated arms and pressed against the inclined surface 195S as the unmanned vehicle half 137A moves downwards onto inclined surface 195Q and into angled gap 195R.

Generator 189B is then activated and generator 189A de-activated so that the articulated arms can lift vehicle half 137A across gap 195R and stack it on half 137B adhering to surface 195S. Vehicle half 137B would drive up inclined surface 195S until it encountered transition 195T, which it would cross by moving 1860 vehicle half 137A onto vertical surface 195U and re-stack vehicle half 137B in the manner taught before.

An articulated unmanned vehicle 186 like that shown (Figs, 12, 13) has multiple downforce generators 189A, 189B has several advantages including redundancy and diversity. Also, the ability to reduce overall power consumption when using a permanent magnetic lifter, which would also be virtually silent, would substantially extend the mission endurance of vehicle 186 operating on magnetic surface if, for example, it was battery powered. For a vehicle with a power cable, it is important to have a cable management system to prevent the cable from being trapped by the vehicle.

A preferred vehicle 186 is battery powered and radio-controlled, though a cable powered and cable controlled variant is equally possible with a cable management system vehicle 186. When cable powered, vehicle 186 would have to be driven carefully to ensure that the power cable and safety cable were not caught by either half vehicle 137A, 13713 and, ideally, the power and safety cables should have to be as close as possible to the surface on which it was running on to minimise overturning and peeling moments.

A telescopic, multi-axis robotic arm could be used to inter-connect the two halves 137A, 137B of vehicle 186 instead of the powered articulated arms 190, 191, 192, 193, 194 shown in Figs. 12 and 13. Such a telescopic robotic multi-axis arm would have to be lightweight and powerful enough to move both halves 137A, 137B of the vehicle precisely and swiftly. A range of tools could be provided on each vehicle half 137A, 137B, e.g. drills, gripper end effectors, screwdrivers, etc., so that each half would be, in effect, a mobile multi-functional workshop.

Fig. 14 shows a tracked ground vehicle 196 with chassis plate 2 and an actuatable inter-connector mechanism 92 that connects the chassis plate 2 to the moveable generator mounting plate 4 onto which different downforce generating / attraction devices can be located. Vehicle 196 has articulated track side units consisting of articulated joints 25 connecting chassis plate 2 to track side plate 28 with flexible track pads 42 pressing onto track 44, driven by sprockets 37, 38. Pads 42 are replaceable. Articulated track side units 25, 28, 37, 38, 42, 44 are as shown in Fig. 1.

A vortex generating downforce generator is fitted on the moveable plate 4 and has motor 96 fast with moveable plate 4, side wall 99 and rubber skirt 100 both extending below plate 4. Proximity sensors or cameras 18, 19, 20 can be fitted around the edge of plate 4 to monitor the separation gap between the plate and the proximate surface to ensure the optimum separation gap and downforce generating efficiency.

The skilled person will appreciate the many variations of vehicle that can be created from the principles taught herein. In Fig. 14, is ground vehicle 196 is adapted to increase its stability so that it can be fitted with a moveable crane jib 197 to lift heavier objects 199 via wire 198. The mobility of the tracked ground vehicle 196, in terms of gradient and surface curvature, would also be increased by fitting it with a moveable plate 4 and downforce generator as well as the articulated track side units 25, 28, 37, 38, 42, 44.

Current unmanned ground vehicles, that are not fitted with a moveable plate 4, downforce generators or articulated track side units and normally have only sufficient traction to ascend rough, flat slopes of less than 500 before slipping. However, a ground vehicle 196, fitted with a moveable plate 4 and a downforce generator / attraction device, would become a flat, inclined plane or wall climbing vehicle. Another advantage of this is that the downforce generator could be raised slightly to give a larger operating surface 200-to-plate 4 clearance to go over rough terrain and obstacles without the generator being damaged.

When vehicle 196 is mounted a non-horizontal surface, e.g. a wall or side of a ship, the generator / attraction unit clearance could be set to enable vehicle 196 to ascend vertical surfaces as a wall climbing vehicle. If the usual fixed track sides retro-fitted with articulated track sides units 25, 28, 37, 38, 42, 44 (as shown on Fig. 14), and plate 4 is provided with a downforce generator/attraction unit, then the previously ground restricted ground vehicle 196 could also ascend curved surfaces 200 of any gradient, as its articulated track units 25, 28, 37, 38, 42, 44 could better conform to any curved surface than fixed track side units, so improving the traction between its tracks and the proximate curved surface.

Where the location, width, orientation and cover depth of rebars (reinforcing bars used to strengthen concrete structures) needs to be ascertained, e.g. if drilling work, decommissioning or scabbling have to be undertaken on reinforced concrete structures, rebar detectors and cover meters are all currently manually scanned across the structures.

Unfortunately, such structures can be many metres high and often located in contaminated or hard-to-reach environments, which make it difficult, unsafe and / or expensive to access to use manually operated equipment. Fig. 15 shows unmanned wall climbing vehicle 1, with a movable plate 4 connected to a threaded collar-type 92 actuator and fitted with a rebar detector 204. Vehicle 1 (as taught with reference to Fig. 10) has rebar detector 204 on side mounted linear actuator 206 and is provided with a permanent marker pen 205. Linear actuator 206 would lower and raise the permanent marker pen 205 when detector 204 found a rebar 202 so marking its position and orientation in the reinforced concrete structure 201. Cameras could also be mounted above detector 204 to show the pen markings to the operator remotely on a display screen. Detector 204 is attached to an elevatable arm 207 connected to a powered joint or servo 208 on outrigger 23. Detector 204 is elevatable above the outrigger 23 when not in use, so that the vehicle 1 can reach the area of interest without it impeding movement. Detector 204 can be used remotely by its human operator, who can remain safely on the ground, out of potential danger.

Arm 207 moves the rebar detector 204 up and down and away from and towards vehicle 1. This is important as vehicle 1 may have magnetic, metallic components which could interfere with the rebar detector 204 if it was too close. Thus, arm 207 should be made from a strong, lightweight non-magnetic material to avoid interference with the detector.

Rebar detector 204 carrying vehicle 1 will thus provide a non-destructive means of locating the size and orientation of rebars 202 in concrete structures and also measure the depth of concrete 203 cover. Current rebar detectors 204 can also produce 2-D images and displays of the underlying rebar 202 arrangement. Vehicle 1 (Fig. 15) could even be used to transport and operate a surface penetrating radar scanner. Such scanners can detect not only rebars 202 but also tensioning tendons, metal pipes, plastic pipes and electrical cables. They are able to produce detailed 3-D cross-sectional representations of concrete structures, so an unmanned vehicle 1 offers enormous non-destructive analysis capabilities of hard to reach structures.

The structural integrity of composite wind turbine blades and metal, or concrete, towers needs to be ascertained to ensure their safe and reliable operation as they are exposed to adverse weather conditions, especially if located offshore. Such structures are presently inspected by personnel either by abseiling down or on the ground using high resolution cameras and ultrasonic equipment to locate and identify potential defects. Such manual inspections are expensive, have health and safety implications and weather conditions limit the days on which such structures can be safely inspected. Fig. 16 shows a cross-sectional view of a hollow wind turbine blade 209 and unmanned vehicles 1, similar to that described in Fig. 10 A, moving on the curved outside 210 and curved inside 211 surfaces of blade 209. The leading edge 212 is prone to erosion and damage from rain, hail and bird strikes and needs annual inspections. Trailing edge 213 is prone to delamination of its internal fibres due to flexing of whole blade 209.

Inside curved 211 surfaces of blade 209 at trailing 214 and leading 215 edges are usually inspected manually by operators using ladders and / or abseil lines inside the blades. Inspection vehicle 1 has a chassis plate 2 and a moveable plate 4 and generator moveable by an actuator, e.g. threaded collar 92. Two powered articulated track units 25, 28, 34, 37, 38, 42 and an unpowered wheeled unit 26, 30, 39, 40 create a tripod-like vehicle 1.

Proximity sensors or cameras 18,19,20 and lights (not shown) are fitted equi-distantly around the edge of the moveable plate 2 enable the on board controller to move threaded collar 92 to maintain optimum separation distance between the generator and the proximate, multiple and complexly curved outer 210 and inner 211 blade surfaces. A vortex generator (taught with respect to Fig. 6) is suitable for the Fig. 16 application.

Vehicle 1 has a cable management support arm 45, rotatable through 360° and a strain relief sock 46 attaches power cable 47 to support arm 45. This ensures that power cable 47 never supports the weight of vehicle 1, thus preventing the connection from coming loose or being broken off vehicle 1. Power cable 47 is preferably spooled loosely to the vehicle to maximise heat transfer to the air and to minimise induction heating effects. Ideally, a safety line 48 is also attached to the rotatable cable management support arm 45 so that it, and not power cable 47, supports the weight of vehicle 1 in the event that it loses adhesion to the surface on which it is moving.

Cable support arm 45 and safety line 48 should always be kept as taut as practicable so that the vehicle 1 does not fall and swing uncontrollably against the surfaces 210, 211 if it loses its adhesion; this should also ensure that neither surface nor vehicle 1 are damaged. They should also be kept close to the blade 209 to minimise overturning torque on the vehicle. Cable arm 45 allows vehicle 1 to manoeuvre in any direction in / on the blade without risking the power cable 47 and safety line 48 getting caught in the track or wheel units. Interconnecting straps 216, attached every 5 metres or so, locate power cable 47 against the tensioned safety line 48 to ensure that it does not move too much in the wind when vehicle 1 is on external wind turbine blade surfaces 210. Vehicle 1 could fully inspect the blades and tower remotely using a range of instruments as payload 222, e.g. thermal imaging cameras, ultrasonic inspection sensors, etc. as well as a high resolution scanning camera 217 and relay the data / images to operators in a safe location.

Vehicle 1 could also be used for research, e.g. install lightweight self-adhesive, backed vortex generators 224 at specific locations on the outside surface 210 of blade 209 to study the aerodynamic properties and optimise future designs.

Fig. 17 shows a VTOL unmanned aerial vehicle (UAV) 225 landing on an inverted curved surface 231. The VTOL UAV 225 could fly towards any curved surface, even if it was moving, using its rotatable thrusters 226, 227. Once it was within, say, 500mm from a surface 231, the doors 230 would open and powered arms 228, 229 would extend the articulated tracked vehicle system 1 towards the surface 231 until it made contact, was powered up and attached itself to the surface.

Downforce plate 4 can have different types of generator fitted, including magnetic lifters or vortex generator (shown in Fig. 6). Use of a magnetic lifter fitted would allow VTOL UAV 225 to perch against magnetic / metallic objects such as ships, vehicles, aircraft and stare for long periods of time without producing any noise or using any power, so permitting long term endurance, covert surveillance missions which other VTOL UAV's with conventional tripod-like undercarriage legs could not accomplish. Proximity sensors 18, 19, 20 would control the approach, landing and subsequent take off in conjunction with thrusters 226, 227. The curved / inclined / inverted surface operational capability includes train roofs, moving vehicles, ceilings and even flying aircraft, where it could accomplish complex missions ranging from taking core samples using, an on-board drill, to taking high resolution images, i.e. substantially improving operational capabilities.

Fig. 18 shows an unmanned underwater vehicle (UUV) 232 perching on a vertical curved surface 239, e.g. an underwater pipeline, underwater section of a wind turbine tower, submarine or ship hull or etc. The UUV 232 could swim towards any static or moving curved surface 239 and secure itself to that surface in a similar manner to that described for the VTOL UAV above and monitor that surface or operate covertly. If a vortex generator (shown in Fig. 6) was to be used, it would be designed to operate in water. A magnetic lifter would have the potentially long mission time taught above. UUV 232 could perch on moving submarines, or ships, and perform complex missions ranging from taking core samples or high resolution images of the structure and silently leave at the end of the mission.

At present, UAV's and manned helicopters use a mechanical hook anchor when they land on rolling flight decks or oil platforms. The under-fuselage hook grabs onto a thick mesh located on the flight decks and they basically anchor the UAV's or helicopters to the rolling flight decks. Fig. 19 shows a manned / unmanned helicopter 240 or VTOL UAV with outrigger legs 241, 242 and double-sided vehicle systems 137, as shown in Fig. 12. The approach and engagement system would be as taught above and, once landed, manoeuvre the UAV, for example, into a hangar. UAV 240 could also safely land on a moving and curved submarine hull 246 at sea 247, which is not possible with current UAV's/helicopters.

Fig. 19 shows a manned / unmanned helicopter 240 with an additional articulated tracked vehicle system 137 located underneath the fuselage by two cables 243, 244. System 137 carries a payload, e.g. ferrous cylinder 245, which may be deposited where and when required by lowering cables 243, 244. This sky-crane configuration of helicopter 240 allows objects to be transported conveniently, especially those which are bulky, or curved or otherwise difficult to handle.

The sky crane principle could assist material handling, e.g. by minimising the need for slings, etc. and enabling the operator to manipulate a load on a crane, e.g. to find the centre of gravity or to align a load to the angle at which it is to be fitted. Fig. 20 shows a crane 248 with a system 137 remotely lifting a cylindrical object 251. Within its capabilities, the tracks on vehicle 137 could move cylinder 251 laterally or rotationally as shown by the arrows on the cylinder, while held by wire 250 on jib 249. The Fig. 20 system could reduce manning requirements and keep people away from raised objects.

A number of applications of the invention have been taught above and, on the basis of 30 these, the skilled person will be aware of developments of these applications and many others applications all falling within the spirit and scope of the invention,

Claims

Claims:- 1. A surface effect vehicle comprising:-i) a downforce generator; ii) a means of supplying power to drive the downforce generator; iii) a plurality of wheels or wheel-equivalent means; iv) a means of mounting the downforce generator in relation to the wheels or wheel equivalent means, said mounting having articulated means of movement in at least the roll, pitch and yaw planes; v) means to monitor the angular relationship between the downforce generator and the surface and to cause the generator to be moved (roll, pitch and / or yaw) in relation to the surface to establish and maintain the angle between the downforce generator and the surface as near normal as practicable; vi) means to move the downforce generator translationally in at least the Z plane (where the Z plane is essentially normal to the plane or to a tangent to the plane of the surface adjacent to the vehicle) i.e. towards and away from the surface; vii) means to monitor the separation distance between the downforce generator and the surface and to cause the generator to be moved (Z plane) in relation to the surface to establish and maintain the optimum separation distance; and viii) means to mount equipment on the vehicle so that it can perform operations; characterised in that the vehicle is powered up and driven on a surface from where it moves via its wheels or wheel equivalent means to a desired location all the time monitoring the separation distance (Z plane) and angular orientation (roll, pitch and / or yaw) between the downforce generator and the surface and maintaining these at the optimum values via the Z plane movement and the articulation means respectively and, when at the desired location, performing the allotted operation(s) using the on-board equipment and thereafter either returning to a predetermined position or to another location to perform another operation(s).
2. A surface effect vehicle, as claimed in claim 1, wherein the downforce generator is a vortex generator as taught in co-pending patent application No. GB 12 21490.4.
3. A surface effect vehicle, as claimed in claim 1, wherein the downforce generator is a magnetic device.
4. A surface effect vehicle, as claimed in claim 3, wherein the magnetic downforce generator employs variable magnetic field generating or magnetic lifting or permanent magnetic or electromagnetic technology.
5. A surface effect vehicle, as claimed in claim 1, wherein the downforce generator is a device employing passive pneumatic suckers.
6. A surface effect vehicle, as claimed in claim 1, wherein the downforce generator is a device employing active pneumatic suckers.
7. A surface effect vehicle, as claimed in claim 6, wherein the active pneumatic sucker downforce generator includes a compressor or vacuum pump.
8. A surface effect vehicle, as claimed in claim 1, wherein the downforce generator is a device employing Bernoulli grip hollow pads.
9. A surface effect vehicle, as claimed in claim 1, wherein the downforce generator is a device employing induced electro-adhesion means.
10. A surface effect vehicle, as claimed in claim 1, wherein the downforce generator is a device employing microscopic cilia gecko-like means.
11. A surface effect vehicle, as claimed in claim 1, wherein the downforce generator is a device employing forced vortex impellor-like means.
12. A surface effect vehicle, as claimed in claims 2-11, wherein the downforce generator is detachably mounted in the surface effect vehicle.
13. A surface effect vehicle, as claimed in claim 12, wherein the detachable mounting in 30 the surface effect vehicle is a universal mounting into which any type of downforce generator is fittable so that downforce generators may be replaced or interchanged as required.
14. A surface effect vehicle, as claimed in any preceding claim, wherein the vehicle incorporates a plurality of downforce generators said plurality including more than one of the same type of generator or a combination of different types of generator.
15. A surface effect vehicle, as claimed in any preceding claim, wherein the power is supplied via an external means.
16. A surface effect vehicle, as claimed in claim 15, wherein means are provided to prevent an external power supply cable from entanglement with the vehicle or parts thereof.
17. A surface effect vehicle, as claimed in any preceding claim, wherein the power supply is on-board the surface effect vehicle.
18. A surface effect vehicle, as claimed in claim 17, wherein the on-board power supply is a battery.
19. A surface effect vehicle, as claimed in claim 17, wherein the on-board power supply is an internal combustion engine or turbine with its own supply of fuel.
20. A surface effect vehicle, as claimed in claims 15-19, wherein the wheels are steerable or omnidirectional (in the X and Ne planes) and deployed either singly or in multiple bogie arrangements.
21. A surface effect vehicle, as claimed in claims 15-19, wherein the wheel equivalent means are independently-steerable tracked means.
22. A surface effect vehicle, as claimed in claims 20-21, wherein the plurality of wheels or wheel equivalent means is at least three, arranged in a stable configuration.
23. A surface effect vehicle, as claimed in claim 22, wherein the plurality of wheel or wheel equivalent means is one wheel and two independently steerable tracked means.
24. A surface effect vehicle, as claimed in claims 20-21, wherein the plurality of wheel or 30 wheel equivalent means is four independently steerable tracked means.
25. A surface effect vehicle, as claimed in claims 20-24, wherein the plurality of wheel or wheel equivalent means includes flexible mounting either of the bogie(s) or tracked means themselves or within the bogie(s) or tracked means to allow the wheel or wheel equivalent means to conform to the curvature(s) of the surface on which the vehicle is operating.
26. A surface effect vehicle, as claimed in any preceding claim, wherein the articulated means include linear actuators and flexible joints.
27. A surface effect vehicle, as claimed in any preceding claim, wherein the articulated 5 means include cam mechanisms.
28. A surface effect vehicle, as claimed in any preceding claim, wherein the articulated means include hexapod or Stewart Platform type arrangements.
29. A surface effect vehicle, as claimed in claims 26-28, wherein the means of moving the generator in the Z plane includes a screwed means.
30. A surface effect vehicle, as claimed in claims 26-28, wherein the means of moving the generator in the Z plane includes a linear actuator.
31. A surface effect vehicle, as claimed in any preceding claim, wherein the means of mounting the generator in relation to the wheels or wheel equivalent means includes a moveable plate or collar.
32. A surface effect vehicle, as claimed in any preceding claim, wherein the means to monitor the separation distance and angular orientation between the downforce generator and the surface includes a camera(s) and / or a distance sensor(s) providing input to a controller which compares the input data with reference data in its memory and uses the difference(s) between the two sets of data to generate the required correction(s) and sends a correction signal(s) to the appropriate means to effect corrective action to restore the separation distance and orientation to as near the pre-set optimum values as practicable.
33. A surface effect vehicle, as claimed in any preceding claim, wherein appropriate mountings are provided for equipment to be carried on the vehicle and for the operations to 30 be performed.
34. A surface effect vehicle, as described in and by the above statement with reference to the accompanying drawings.