APPARATUS AND METHODS FOR REMOTE INSPECTION OF STRUCTURE FACADES

Abstract: A remote inspection drone (4) having an imaging device (6) for recording images of traversed regions of a building façade. A position indicating device for indicating the position of the inspection drone (4) relative to one or more predetermined reference points, and recording the respective indicated positions for each of the recorded images of the façade.

Description: APPARATUS AND METHODS FOR REMOTE INSPECTION OF STRUCTURE FACADES Field of the Invention The present invention pertains to apparatus and methods for the systematic inspection of the facades of large and tall structures utilizing a remote imaging device. Background of the Invention Previously, structural inspection was done by erecting swing stages, which are platforms on which men or women stand. The inspectors would either merely visually note defective regions and record their general location, or take photos of various regions. Such swing stages are undesirable in that they require persons to be perched at high locations. Even under the best weather and other conditions, ascending several hundred feet in the air on a cable is an uncomfortable and distracting position in which to attempt an engineering analysis. Hence, the collected information was incomplete and consisted of a few notes and still photos. Also, there was lacking any consistency from one inspection to the next. These inspection methods were relatively quite expensive and labor intensive. In fact, the high cost of the prior art building facade inspections was so great that, in practice, typically an inspection would only be undertaken of approximately 15-25% of the actual structure's surface, and this limited data was then required to be extrapolated to arrive at a rough estimate of the work and expense required for the entire building facade. Unmanned equipment currently in use is undesirably heavy in construction, and requires a crew to relocate the equipment. The tension system for the guide wires which guide the imaging device are too large and cumbersome to move sufficiently quickly. Hence, current structures and systems lack flexibility, which prevents their use on irregular shaped structures and where adjacent areas are congested or limited in space. Also, due to the heavy weight of the equipment and its attachments, current systems may cause damage to the building facades during inspection. Additionally, the delivery, storage, erection and disassembly of previous structures and systems required a large assembly area and caused traffic disruption in congested areas. The existing problem is that only two methods of facade inspection are currently available. 1. Long distance telescopic inspection where the building is viewed from a distance with binoculars in an effort to locate defects and evaluate the overall condition of the facade. Dramatic failures of buildings inspected in this manner have triggered proposed legislation that may outlaw this method as acceptable for ordinance compliance. 2. The second alternative is to erect swing stages and traverse the building. This system requires two experienced riggers and one engineer to spend long days in the air under extremely adverse conditions. The swing stage method has been the only viable inspection method to date. SUMMARY OF THE INVENTION In accordance with one aspect of the present invention, an apparatus for remote inspection of building facades is provided. An inspection drone is used for traversing the building facade, with the inspection drone having an imaging device, such as a camcorder or the like, for recording images of the traversed regions of the facade. A support structure is provided which is lightweight and flexible, for supporting and guiding the inspection drone in a selective path along the building facade, such as successive vertical paths. A position indicating device is provided for indicating the position of the inspection drone relative to one or more predetermined reference points, and for recording the respective indicated positions for each of the recorded images of the facade. The plurality of scanned images may be assembled so that a plurality of separate images of the building facade may be combined to create a single composite image. In accordance with another aspect of the present invention, an apparatus is provided having a support structure for the apparatus which has a pressure assembly for biasing the inspection drone against the building facade, to al low for inspection of angled surfaces. In accordance with a further aspect of the present invention, a method for remote inspection of a building facade is provided. An imaging device is used, and a plurality of selective regions of the building facade are imaged with the imaging device and recorded. A position indicating device is used for indicating the position of the imaging device relative to one or more reference points. The location of the imaging device as it traverses the building facade is recorded along with the plurality of respective images taken. KK. The entire drone assembly with camcorder weighs 10 pounds. This is 1/100 th the weight of the prior art. LL. Survey inspectors conclude with 95% to 100% of facade surfaces being recorded as archival data. This is a 10- to 20-times increase in archival data when compared to the prior art. MM. Archival data of 95% to 100% of fagade surfaces can be provided to professionals for second opinions without re-surveying the fagade from a scaffold. NN. Due to the economical cost of the data acquisition, it is possible to perform affordable guarantee inspections to protect the investment associated with major repairs. OO. The equipment can survey approximately 20,000 square feet of wall surface during each 8 hours of operation. This is a four-fold increase from prior art. 23. Due to the heavy weight of the equipment and its attachments, damage was caused to the building's surface and ornamentation. 24. The heavy equipment required large diameter cables that caused damage to the fagade. 25. The delivery, storage, erection and disassembly of previous equipment required a large assembly area and caused traffic disruption in congested areas. 26. Previous equipment was in a constant state of assembly and disassembly that created an on-going hazard to public safety. 27. Due to hazardous working conditions, employers pay a premium of 20% of each dollar paid an employee to workmen's compensation insurance. 28. It takes one crew-day (usually a 3-man crew) to assemble a power scaffold to make it functional. 29. It takes one crew-day (usually a 3-man crew) to disassemble a power scaffold and remove it from a site. 30. Counter balance weights placed on the roof to support the scaffold require special cushioning devices to protect fragile roof membranes from damage. 31. It takes approximately 2 hours of an 8-hour day to mobilize equipment, allow workers to take breaks and de-mobilize equipment. The actual productive time for survey work is 6 hours of a normal 8-hour day. 32. Scaffolds are normally operated during daylight hours. Rarely are scaffolds operated by a second or third work shift. 33. A fully loaded scaffold (men and equipment) weighs 1 ,000 pounds. 34. Scaffold inspectors conclude with 3% to 5% of actual wall surfaces being recorded as archival data. Due to the limited quantity of data collected, comparing data from different survey inspections is restricted. 35. Procuring second opinions regarding the condition assessment of a fagade requires a re-inspection of the fagade. Due to the excessive cost of repeating a scaffold inspection, second opinions are generally unfeasible. 36. Due to the excessive cost of scaffold inspections, re-examination of facades to determine if repairs which are under guarantee are performing rarely occurs. Typically, contractors' defective work is not known until guarantees have expired. 37. A scaffold inspector will cover approximately 5,000 square feet of wall surface in a typical 8-hour work shift. Advantages and Solutions Which Have Advanced the State of the Art. 1. Engineers and riggers no longer at risk of equipment failure and accident. 2. Heavy equipment no longer above public areas. 3. Heavy equipment no longer contacts the building, damaging the fagade. 4. It is economically impractical to survey more than 25% of a building using a swing stage. A drone can survey nearly 100% of the building for the same cost. 5. A drone records all of the building's surface defects. 6. A drone indexes the location of all surface defects. 7. All past and future surveys are also indexed on the same benchmarks. 8. Drone data is archival and can cover the entire life of the structure. 9. A drone guidance system is accurate enough to provide overlay comparison. DETAILED DESCRIPTION OF THE PREFERRED EM B ODIMENT S This preferred embodiment of our invention is a description of a lightweight, portable and flexible assemblage of mechanical, electronic and optical modules which comprises a system for inspecting the fagade of large and tall structures. Referring to the drawing, Fig. 1 , this figure illustrates the overall system layout of one preferred embodiment of this device. Power Head Module Drawing Fig. 2 is a detailed layout of a power head module 1. This module contains an electric motor 10 with reversible speed control and gear reduction. Motor 10 is controlled by a hand-held remote power head control station 11 which is attached to the motor controls by a multi-strand electric cord. The electrical power for motor 10 is supplied by battery, generator or line voltage (not shown). Mounted on the gear reduction unit is a cable reel 13 which is capable of storing large quantities of cable. Mounted on cable reel 13 is a cable guide 14 which positions the cable in an orderly fashion on cable reel 13. This cable is drone-positioning cable 8. Aligned with cable reel 13 is a mounting point 15 for an umbilical terminator fitting 16 to be attached. A power head transporter 9 is a wheeled chassis for transporting the power head module components, and supplies hard points to mount components and accessories. Drawing Fig. 1 is a general layout of the most preferred embodiment of our invention. This embodiment consists of five major modules, power head 1, umbilical 2, parapet boom 3, inspection drone 4 and drone location transmitter 5 and visual module 6. These modules are highly mobile and, with the available accessories, can adapt to almost any structural configuration. Drawing Fig. 2 is a detailed layout of our power head module 1. This module is a motorized cable reel that is controlled by an operator from a position near the power head 1. This operator will normally be at the uppermost level and can safely supervise the complete system. The operator has a hardwire remote control station 11, which has instant response and is not susceptible to outside interference. Control station 11 has a stop, start, reverse and a motor speed control. This controller 11 operates motor 10 that, through a gear reduction, turns cable reel 13. Cable reel 13 has a cable guide 14, which organizes the cable on the reel 13. The systematic organization of the cable allows the use of cables more than 1 ,000 feet in length. These components are attached to a lightweight wheeled power head transporter 9. This transporter 9 acts as a chassis with hard points to mount accessories. Hard point, umbilical terminal mount 15 is critical in that it is the attachment point that connects power head 1 to umbilical 2. The cable which is controlled by power head 1 is called drone positioning cable 8. Drone positioning cable 8 passes through the guidance of several modules and eventually is attached to inspection drone 4 (Fig. 1 and Fig. 8). The primary job of cable 8 is to support the weight of inspection drone 4 (Fig. 1 ). When the equipment operator reels in cable 8 then drone 4 is lifted higher and when cable 8 is paid out then drone 4 is lowered. This preferred embodiment of our invention is a description of a lightweight, portable and flexible assemblage of mechanical, electronic and optical modules which comprises a system for inspecting the fagade of large and tall structures. Referring to the drawing, Fig. 1 , this figure illustrates the overall system layout of one preferred embodiment of this device. Power Head Module Drawing Fig. 2 is a detailed layout of a power head module 1. This module contains an electric motor 10 with reversible speed control and gear reduction. Motor 10 is controlled by a hand-held remote power head control station 11 which is attached to the motor controls by a multi-strand electric cord. The electrical power for motor 10 is supplied by battery, generator or line voltage (not shown). Mounted on the gear reduction unit is a cable reel 13 which is capable of storing large quantities of cable. Mounted on cable reel 13 is a cable guide 14 which positions the cable in an orderly Umbilical System 1.) The umbilical system is a mechanical connection between the power head and the parapet boom. 2.) The power head generates motion in the form of a cable which is reeled in or paid out. This motion is transmitted to the parapet boom by the guidance and incompressability of the umbilical's cable sheath. 3.) The motion of the power head cable is guided by the parapet boom to the inspection drone. 4.) The inspection drone is supported by the power head cable and is locatd at any desired elevation along its wire guides by the action of the power head. 5.) The design of the umbilical system is unique in that the actual components are familiar to many applications, but the actual operational applications are new. Note the following: A.) Normally a spiral-wound cable sheath is used when power is transmitted by rotating the central cable, as in a rotary flex shaft. The second most common use is when the cable is moved only a very limited distance and is used as a flexible control rod, as in a carburetor control or a bicycle brake. In this application the central cable can transmit motion, both in free fall and under tension, over an unlimited length of cable without rotary friction or adjustment limitations. B.) The spiral-wound cable, which acts as if it were a rigid tube, is susceptible to contamination and must be protected with a pliable cover. In this case the pliable cover acts as a storage reservoir for oil. When the sheath is flexed by tension, the oil enters and lubricates the cable and the walls of the sheath, protecting the surface and reducing friction. C.) The end caps are made of brass or other material which is wear resistant and will not damage the cable when the cable passes through the guide holes. D.) The end caps and terminator tee fitting have full length cable slots t\so that they can be removed and replaced at any point in the cable and need not be threaded off the end of the cable causing long delays. E.) The thread end cap slips over the cable and screws on to the tee fitting. When the cap is properly installed, the cable slot in the cap will not align with the cable slot in the tee fitting, locking the cable in the tee fitting. F.) The tee fitting is designed to be attached by placing the mounting stem into a mounting hole and securing it in place with a removable pin. G.) The overall length of the umbilical system is variable. With its built-in lubrication supply, length does not impose severe restrictions. H.) The umbilical system permits the parapet boom to be mounted a considerable distance from and above or below the power head. I.) If additional lubrication is required, dismount one of the terminator tee's, turn the mounting stem bottom-up, and pour oil into the bottom stem opening. J.) If wear is discovered in the wire sheath, it can be replaced by removing a tee fitting cap and sliding the sheath off the end of the cable. A new sheath can be slipped over the cable into the umbilical cover and locked into place with the end cap. Umbilical system module 2 (Fig. 1 , Fig. 4, Fig. 5, Fig. 6 and Fig. 7) illustrate the detailed components of our umbilical system. Umbilical 2 is a flexible power transmission connector between power head 1 and parapet boom 2 (Fig. 1 and Fig. 3). The power in this case is the linear motion of drone positioning cable 8. We believe that our umbilical 2 is a unique application of a familiar appliance. A cable surrounded by a spiral wound incompressible wire sheath 18 (Fig. 4) is used to transmit rotary power as in a powered flex shaft. The other most common applications are as a control positioner where the cable has limited travel or when the travel of the cable is stalled. These two applications could be described as a throttle and a brake. Our umbilical allows us to have continuous uninterrupted control and power transmission to equipment more than 1 ,000 feet from the power source. The umbilical is a coaxial system in that a center cable 8 is surrounded by a tubular shaped wire wound sheath 18. The wire sheath 18 has a tubular terminator tee fitting 16 attached to each of its ends. The final closure at the open ends of the terminator tee fitting 16 is a brass threaded end cap 17. Covering nearly the entire umbilical is a pliable wire sheath cover 19. Positioning cable 8 support the weight of the inspection drone 4 at all times but when the drone is lifted cable 8 is put under considerable tension. Under these conditions wire sheath 18 acts as an incompressible tube regardless what shape it assumes. This incompressibility feature prevents the cable 8 tension from moving the equipment attached to the ends of the umbilical 2. The equipment acts as if it were connected by a rigid beam when, in fact, the connector is draped over and around obstacles. The tee fitting 16 attached to each end of the wire sheath 18 are mounting fixtures which allow the umbilical 2 to be connected to other modules. These tee fittings 16 are threaded at the ends of all of their legs. The leg into which wire sheath 18 is inserted is called the tee bar 27. The tee bar 27 has a wire sheath locking device 26 and has a cable entry slot 21 machined from end to end of the tee bar 27 (Fig. 4). The cable entry slot 21 allows the tee fitting to be removed from the cable at any point convenient. The leg of the tee fitting, which is perpendicular to the tee bar, is the tee body mounting stem 25. The stem is an anchor pin that is inserted into an umbilical terminator tee mount 15 when attaching the umbilical 2 to another module. A threaded cap 24 with a wide flange is screwed onto stem 25. Cap 24 locks the stem 25 into mount 15 attaching the umbilical 2. At the extreme ends of the umbilical 2, mounted on the tee bar are threaded brass end caps 17 (Fig. 4). The end caps 17 absorb the complete end thrust of the wire sneath 18 and therefore must be heavy duty construction. A cable guide hole 22 is drilled in the end of each cap 17 (Fig. 6). Brass is the preferred material because it is unlikely to damage the cable and wears well under abrasive conditions. The end caps 17 have a cable entry slot 21 machined their full length and into the cable guide hole 22. The cable entry slot allows the end cap to be removed and replaced at any point on the cable. If a wire sheath 18 requires replacement, remove an end cap 17 and the sheath can be slid out of the umbilical 2. The wire sheath slides off the end of the cable 8. A replacement sheath 18 is fed onto cable 8 and slid into the umbilical 2. The cap is replaced and work can begin, no system adjustments required. The final umbilical 2 concentric component is a pliable sheath cover 19. This pliable cover 19 is a dirt shield to protect the wire sheath from ingesting contaminates. The wire sheath, if not protected, would lay on roofs, sand and water. The pliable cover 19 can be any material that is pliable, water resistant and compatible with lubricants. In most situations, the cover 19 needs to be very flexible but in conditions where vehicle traffic may damage the sheath, a stiff, heavy cover is required. Under most conditions, a simple clamp or seal 20 will be adequate where the pliable cover 19 mounts on to the tee bar 27. If necessary, the pliable cover can be sealed with a liquid tight compression fitting (Fig. 7). The pliable cover also acts as an oil reservoir. Lubricating oil can be added to the umbilical 2 by removing cap 24 adding a small amount of oil into mounting stem 25. The oil will collect in low point of the umbilical and wet the cable as it passes. This unique system works very well, suffers little wear and seems to have no length limitations. The umbilical system allows the power head to be located at nearly any height or relationship to the other modules in the system. This inherent flexibility makes this system the first commercially viable unmanned fagade inspection equipment. The parapet boom module 3 (Fig. 1 and Fig. 3) controls and locates the drone positioning cable 8, the guide cables 34 and 35 and the handling of the tension weights 42 and 43. The parapet boom module 3 must be strong enough to perform as a light duty crane. The module must be light and flexible enough to be efficiently relocated every few minutes without any wasted motion. In addition to the above duties, the module is, in actuality, a camera boom. The positioning of the camcorder from the fagade and the angle which the camcorder views the fagade is critical. The parapet boom 3 is the guiding device for the other movable portions of the system. The ultimate result of this equipment is to position a camcorder out in space so that it can, without interference, clearly and efficiently image the fagade. The main structure of the parapet boom module 3 is a rigid beam 31 (Fig. 3). This beam 31 made of metal and tubular in shape. It can be in one piece or made up of several pieces. Other materials and profiles can be used to meet job requirements. The beam 31 is balanced on a fulcrum, which in this embodiment is a wheeled truck 28. This truck can be rested on the parapet wall or roof and be rolled to a new location. The tires are soft and do no damage and safely grip the stone surface. The beam pivot mount which attaches the beam to the truck also pivots. This pivoting attachment permits the beam to be positioned at nearly any angle in reference to the wall. This provision permits the convenient negotiation of complex building shapes. Beam 31 must withstand the loads imposed on it by the cables, weights and equipment suspended over the side of the structure. Counter weight 30 (Fig. 3, "B-B") is attached to the rear of beam 31 to balance the loads from the opposite end of the beam 31. The loading of the beam 31 by the forward cables is highly variable, therefore rear beam stand 29 is provided to level the beam and support the counter weight during these periods of fluctuating loads. In reality, the purpose of the parapet boom 3 is to guide and support cables. There are two groupings of cables. One could be described as active and the second could be described as passive. The active cable is the drone positioning cable 8 that raises and lowers the inspection drone 4 (Fig. 1 ). This cable is in motion during the actual inspection and is powered by a remote piece of machinery and controlled by a distant operator. This cable 8 is brought to the parapet boom through the umbilical. The umbilical is attached to the parapet boom 3 by tee 16. Cable 8 is guided under beam 31 and past the stand 29, counter weight 30, winch 37 and truck 28 to support shive 32. Cable 8 passes over shive 32 and turns downward to be attached to inspection drone 4 (Fig. 1 and Fig. 9). Cable 8 raises and lowers the inspection drone as a camcorder 77 images the structure. The passive cables are guide cables 35 and 36 which are only in motion when the equipment is being moved or set up. The passive cable layout is the feature that makes the parapet boom so fast and versatile. The devices which make this speed and flexibility possible are two hand winches 37 and 38 mounted on the rear half of the beam 31 (Fig. 3). One winch 38 above the beam and one winch 37 below. These winches control the inter guide cable 35 and outer guide cables 36. The winches 37 and 38 put the handling and location of the weights 42 and 43 under the control of the rooftop operator. This topside weight control is most critical when relocating the boom 3. The roof top operator can lift these weights 35 and 36 and move over tree, buildings and other adjacent obstacles. If a particularly difficult obstacle is encountered, the weights 35 and 36 can be suspended in midair while that particular area is being inspected. In addition to normal bulk weights 42, long slim pipe weights 43 have been developed. Pipe weights 43 are lowered from above down through trees or between closely spaced obstacles. The pipes 43 are then attached to anchors or stakes if high cable tension is required. When high cable tension is required, the beam mounted winches 37 and 38 allow the operator to put the maximum tension on each cable 35 and 36 without damaging the equipment. Umbilical System Module Drawings Fig. 1 , Fig. 4, Fig. 5, Fig. 6 and Fig. 7 illustrate the detailed components of an umbilical system 2. Umbilical system 2 is a flexible power transmission connector between the power head 1 and the parapet boom 3. The power in this case is the linear motion of drone positioning cable 8. Drawing Fig. 4 is a center-line section of umbilical system 2 illustrating the relationship between the components. The iπtermost component is inspection drone positioning cable 8. Inspection drone cable 8 is surrounded by a spiral wound wire cable sheath 18. Cable sheath 18 is locked between two terminator tee fittings 16 by a wire cable sheath-locking device 26 in tee fitting body 16. Tubular material is used to fabricate tee fitting body 16 and all open tube ends are threaded. Each tee fitting 16 in section "AA" of Fig. 5 has a threaded end cap 17 which is the closure at the extreme ends of umbilical system 2. Brass is the preferred material for end cap 17. End cap 17 must be heavy duty to withstand heavy thrust loading. A hole is drilled in the center of end cap 17 which acts as a cable guide hole 22. A cable entry slot 21 is machined the full length of a tee bar 27 of tee body 16 in Fig. 5 Section "AA" and of end cap 17 in Fig. 6. Cable entry slot 21 allows tee body 16 and end cap 17 to be removed and replaced on umbilical system 2 without removing cable 8. Umbilical system 2 has tee fittings 16 at each end. Each tee fitting has a tee fitting mounting stem 25 which is used to attach the umbilical to its adjacent module. Umbilical mounting points 15 are built into power head module 1 and a parapet boom module 3 (Fig. 3) to accept a mounting system 25 of umbilical tee body fittings 16. A removable mounting device 24 locks tee fitting 16 into mounting points 15 on power head 1 and parapet boom 3. The preferred configuration (Fig. 4) of removable mounting device 24 is a thread cap with an expanded thrust face. A pliable cover 19 is installed over the exposed wire cable sheath 18. Extra material is provided to allow pliable cover 19 to be slipped over tee bar 27 of terminator fitting body 16. Pliable cover 19 has inside diameter slightly larger than the outside diameter of terminator tee bar 27. An oil and dust seal 20 is installed to act as protective closure. Oil 23 is introduced into the umbilical system 2 through mounting stem 25 of terminator tee fitting 16. Pliable cover 19 acts as an oil storage reservoir. Inspection Drone Module The inspection drone is a chassis which can be restructured to conform to the needs of a specific site or carry any combination of equipment. An inspection drone chassis 52 is a lightweight structure assembled from prefabricated connectors 45 and standard tube stock 51. The configuration incorporates the necessary hard points to mount single or multiple camcorder housings 54, special lighting 55, and additional battery packs 56, and also to increase or decrease the chassis overall size. Prefabricated connectors come in several forms: stock tees and elbows 45, rotating connectors 46, chassis roller guide assembly 47 with guide cable rollers 48. The four corners of drone chassis 52 incorporate prefabricated chassis guide assemblies 47. The assembly consists of a strengthened fitting which has a guide cable slot 50. At the inter end of guide cable slot 50 is a guide roller 48. Guide cables 35 or 36 are inserted into guide cable slot 50. After the guide cables 35 or 36 are inserted into guide cable slot 50, a second guide cable roller 48 is installed, trapping the guide cable 35or 36 between two guide cable rollers 48. This system ensures a smooth, frictionless movement of drone chassis 52 along the guide cables 35 or 36. Drone chassis 52 has a mounting point for a drone location transmitter 5 and camcorder housing 54, which has a mounting bracket 59 for a drone location visual display 6. Inspection drone 4 is stabilized by inter 35 and outer 36 guide cables and vertically positioned by drone positioning cable 8. The drone has sliding electrical brushes which contact inter guide cable 35 and the outer guide cable 36. The guide cable brushes electrically connect the drone to guide cables 35 and 36. The guide cable brushes permit additional electrical power to be transmitted to inspection drone 4 and/or used to control on-board equipment by hard wire. The guide cables 35 and 36 are tensioned by weights 42 and 43. A weight spreader bar 57 maintains a fixed distance between the guide cables 35 and 36. Location transmitter 5 is attached to inspection drone 4 and contacts guide cable 36. Mechanical connection 60 supports drone location transmitter 5 and aligns transmitter 5 with the outer guide cable 36. Electrical connection 58 connects transmitter 5 to visual location display 6 mounted on camera housing 54 (Fig. 10). Camcorder Housing 54 (Fig. 10) A camcorder housing 54 is a weather cover which consists of a operable access door 79. A camcorder mount 80, a camcorder power connector 81 , a protective lens 82 and an adjustable mount 59 for the drone location visual display unit 6. Adjustable mount 59 has movable joints 83 that allow exact positioning of the visual display unit 6. Camcorder housing 54 is mounted on a rotating connector 47 which permits leveling the housing and horizontal centering. Access door 79 allows the camcorder to be placed on its mount 80 and attached to the camcorder battery pack connector 81. A cooling fan 85 or a heater element 86 are operated when extreme conditions exist. Fan 85 and heater 86 require auxiliary battery pack (not shown). The previous equipment covered in this application is only support for the critical module, the inspection drone 4 (Fig. 1 and Fig. 8). The control, stability, placement and consistency of movement of the inspection drone 4 is the result of our developmental efforts. The actual function of the inspection drone 4 is to transport a camcorder. The camcorder images long, vertical strips of the building fagade. The image strips are electronically assembled forming a mosaic of the building's exterior. The overall compatibility of this imaging process is the result of smooth, vibration- free motion of the drone 4. The power head 1 must deliver consistent cable dispensing at the proper rate. The guide cables 35 and 36 must maintain tension. The drone chassis 52 must be rigid and maintain camcorder alignment and move flawlessly. Drawing Fig. I illustrates the general layout and relationship of inspection drone 4 to the other equipment in the system. Inspection drone assembly 4 is made up of components chassis 52, roller connectors 47, camcorder housing mount 5, lighting 5, battery pack 56 and the mounting points for the drone location transmitter 5 and visual display 6. The chassis 52 (Fig. 8) is a general "E" shape with a backbone, two legs and a center camcorder support arm. In actual field practice this embodiment is regularly rearranged into every conceivable configuration. The adaptation of the drone chassis 52 is possible by combining stock tubing 51 elbows and tees 45 with specially designed guidance and positioning hardware. Guidance of the chassis 54 is controlled by four roller connectors 47 (Fig. 8 and Fig. 9). The connectors 47 allow the chassis 52 to move on guide cables 35 and 36 without friction or vibration. Drawing Fig. 9 illustrates the details of roller connector 47 in relation to a typical guide cable. Brass roller 48B is removed from fitting 47. The guide cable is inserted into the vertical cable slot 105. The guide cable in the slot 105 contacts roller 48A. Roller 48B is reinstalled, trapping the guide cable between the two rollers. This roller arrangement is repeated at all four corners, assuring perfect alignment and frictionless movement. Positioning of the camcorder is controlled by rotating connector 46. Connector 46 is adjustable in left to right on a vertical axis and can be plumbed or tilted on a horizontal axis. This adjustment allows the camcorder to view any near-by wall at exactly the required angle. As many as four camcorders can be adapted to this simple chassis. Each camcorder can be assigned to a particular area of interest, each camcorder having its own focus and lighting 55. The camcorders are powered by a battery pack 56. Lighting 55 has a heavy power draw requiring separate power packs (not shown). The exact location of where a camcorder is located at any given moment is very critical. Each image recorded must have circumferential reference and a vertical reference. The circumferential reference is the point on the wall viewed at center of the camcorder image. The angle at which this point is viewed is necessary. This information is recorded and a benchmark is cut into the parapet. The vertical reference is a height and grade for each image. This height is accumulated by a drone location transmitter 5 and imaged by a drone location display 6. These units are mounted on the drone chassis 52 and the camcorder housing 54. The operation of this equipment will be discussed later in this application. Drone positioning cable 8 is attached to the drone chassis by connector 53. Weight spreader bar 57 is used to maintain a prescribed distance between guide cables 35 and 36. Drawing Fig. 10 illustrates a camcorder housing 54. This camcorder housing is an enclosure that protects the camcorder from the outside elements. This housing 54 has an access door 79 that allows entry to place the camcorder on its mount and operate the camcorder. Camcorder housing 54 is mounted on rotating connector 46 that is mounted on the camcorder support arm of inspection done 4 (Fig. 8). Connector 46 enables the housing 54 to be vertically plumbed and horizontally panned. The front of the housing 54 has a protective lens that protects the camcorder lens from being contaminated or damaged. Heater element 86 in cold weather maintains an internal temperature suitable for camcorder operation. Cooling fan 85 maintains a flow of cooling air inside the housing 54 in hot weather. In very severe heat conditions, Pyrex protective lens, reflective exterior coatings, insulation and cooled compressed air can be used to protect the camcorder. At night or in enclosed areas, lighting 55 is attached to the camcorder housing. The camcorder is powered by one or more battery packs 56 attached to the inspection drone 4 (Fig. 8). Location display mount 59 (Fig. 10) is attached to the front of the camcorder housing 54 and is aligned with the center of the camcorder lens. The display mount has two articulating joints, display adjusters 83, which enable the mount to be very precisely adjusted. The display mount supports and positions the drone location display unit 6 so that it is visible to the camcorder. The importance of this capability will be discussed later in this application. Drone Location System The drone location system tracks the height of the drone above or below an arbitrary line or grade. Normally for practical job site use a chalk line or laser scanner is set at a convenient height above actual grade. For our equipment, about four feet is convenient, and is referred to as camera grade. Camera grade can be at several different levels around a structure but each is referenced to a single starting level. At the beginning of each camcorder inspection pass, the camcorder is positioned at camera grade for recalibration. To recalibrate the drone location system, the display is manually set to the camera grade or a known distance above a common reference elevation. By following this simple procedure anyone who is viewing the camcorder tapes will know the exact elevation of each image. Drone Location Transmitter 5 (Fig. 10 and Fig. 11 C) Drone location transmitter is mounted at the lower outside comer of inspection drone 4 (Fig. 8). At this corner, cable 36 leaves fitting 47 of the drone chassis 52. Cable 36 is threaded into the top of the transmitter (Fig. 12) past the calibrated wheel and out the bottom of the transmitter frame. The transmitter measures the accumulative length of cable that passes by the calibrated wheel. The transmitter communicates in one-tenth-of-a-foot increments indicating assent or descent of the inspection drone. Calibrated Wheel Assembly 91 (Fig. 11) Guide cable 36 is held against calibrated wheel 61 by adjustable cable idlers 62. As the inspection drone moves up and down, guide cable 36 passes through the transmitter assembly. The friction of cable 36 on calibrated wheel 61 causes the wheel to rotate. Wheel 61 rotates exactly one rotation for each linear foot of cable that contacts the wheel. Main Shaft Assembly 90 (Fig. 11 A) Calibrated wheel 61 is mounted on main shaft 63 and causes the shaft to rotate. Shaft 63 is mounted on two bearings 64 and at one end of the shaft an auxiliary coupling 72. Cam assembly 89 is mounted on shaft 63 and rotates with the calibrated wheel 61. Cam Assembly 89 (Fig. 11 A) Cam assembly 89 is cam 65 which, in this embodiment, has ten lobes. Special applications may require a different number of lobes. The purpose of cam 65 is to break each shaft rotation into ten equal parts. Each cam lobe 66 signals that one-tenth of a foot of cable 36 has passed calibrated wheel 61. Switch Assembly 71 (Fig. 11 B° Switch assembly 71 is the mechanism that turns rotating cam lobes 66 into electrical impulses. Cam follower 67 is positioned by pivot 70 so that it is on the same plain as cam 65 and perpendicular to shaft 63. As cam 65 rotates, each lobe contacts follower 67 and deflects the follower in the direction of rotation. When follower 67 is deflected it contacts one of the adjacent switches 68 and closes an electrical circuit. Which of the two switches 68 contacted is the result of the direction of rotation of cam 65. The direction of cam 65 rotation is indicative as to whether the inspection drone has been raised or lowered one-tenth of a foot. Both contact switches 68 are connected to the electronic circuitry of drone location display module 6 (Fig. 11C, Fig. 10 and Fig. 8). If a totally closed non-contact switching embodiment was required, sealed proximity switches 88 (Fig. 11 C) could be substituted for contact switches 68 (Fig. 11 B). Magnetic senders 88 (Fig. 11 C) could be molded into the calibrated wheel 61. Cam 65 could be replaced by a sealed ten-point magnetic armature. This sealed system would replace open system 71 (Fig. 11 C). Drone Location Display Assembly 6 (Fig. 1 , Fig. 8, Fig. 10 and Fig. 11 C) Drone location display electrical circuitry 76 is connected to switch assembly 71 (Fig. 11 B). Electrical circuitry 76 responds to pulses from switch assembly 71 and increases or decreases the elevation accumulated on LCD display face 75. This system tracks the vertical location of the inspection drone 4 (Fig. 8) at all times. Drone location display 6 (Fig. 10) is mounted on camcorder housing 54 by mount 59 and positioned by display adjusters 83. Mount 59 is designed to place display face 75 so that when the camcorder is operated the display face readout is recorded. The LCD readout is back-lit and each camcorder image has a clear numerical elevation at the base of each picture. This readout is based on one-tenth-foot increments, but metric or units of measure can be used. The accumulative total is 9,999 units to 3 decimal places. A reset switch 92 is provided, which resets the readout to zero. Camera Dolly Assembly 106 (Fig. 19) Previously in this application we described our inspection drone 4 (Fig. 8). Inspection drone 4, in essence, is a free-floating chassis that carries a camcorder and images the fagade without contacting the structure. This system works very effectively for almost all high rise type structures. We have discovered that certain types of structures require a different kind of inspection drone. Some structures are sited in locations where the wind blows at high speed every day of the year. Structures such as smoke stacks and dams have inclined walls and are best addressed by a wheeled drone that contacts the surface. In fact, we have developed a system for generating force to press the wheels firmly against the structure. Although this force is horizontally applied to a vehicle on a vertical wall, we call it ground pressure. For purposes of clarity, we call our wheeled inspection drone a camera dolly. Drawing Fig. 19 illustrates the general layout of camera dolly assembly 106. Main chassis 109 has bearings 112 to support a front axle 108 and a rear axle 113. Rear axle 113 is narrow and the rear wheels 107 are close to the chassis. Front axle 108 is very wide when compared to the width of the chassis 109. Front bearing 112 allows the chassis 109 to be positioned near the left or the right wheel. The offset axle and wheel acts as an outrigger and stabilizes the dolly in adverse wind conditions. Chassis 109 (Fig. 19) has a rigid camera post 110 and a camera arm 111. Camera arm 111 is mounted on camera post 110 by movable fitting 114 which allows the arm to move along the post. Camera arm 111 is the mounting support for a camcorder housing (not shown). Rotating connector 46 allows the camcorder housing (Fig. 10) to adjust in relation to the imaged surface. Attached to the rear of chassis 109 is the drone location transmitter 5 and mounted on camcorder house 54 is drone location visual display 6. These units communicate through electrical connector 58. Drone Location System The drone location system consists of two major components: drone location transmitter module 5 and drone location display module 6. Mechanical connection 60 attaches the drone location transmitter 5 to drone chassis 52. Electrical connection 58 electrically connects transmitter 5 to visual display 6 which is mounted to the camcorder housing 54. The transmitter module 5 (Fig. 11 , Fig. 11 A, Fig. 11 B, Fig. 11 C and Fig. 12) is made up of several subassemblies: a main shaft assembly 90, a calibrated wheel assembly 91 , a cam assembly 89, a switch assembly 71, location visual display assembly 6 and an auxiliary assembly 78. Main Shaft Assembly 90 (Fig. 11 A) The main shaft 63 is a round, rigid shaft which is mounted on two bearings 64 and is free to turn. Calibrated Wheel Assembly 91 (Fig. 11 ) A calibrated wheel 61 is mounted on main shaft 63. A guide groove 69 is machined in the circumference of calibrated wheel 61. Transmitter 5 is aligned by its mechanical mount so that drone guide cable 36 passes over the face of calibrated wheel 61. Cable 36 engages a guide groove 69. Two adjustable cable idlers 62 maintain the alignment of the cable. Cam Assembly 89 (Fig. 11 A) The cam assembly 89 consists of a cam 65 mounted on main shaft 63 and a cam follower 67 mounted on a pivot 70. Cam follower 67 is held on a plain perpendicular to the center line of main shaft 63. Cam follower 67 is engaged by cam lobes 66 regardless of which direction cam 65 rotates. Switch Assembly 71 (Fig. 11 B) A switch assembly 71 is comprised of two contact switches 68 which are activated by physical contact. Contact switches 68 are on adjustable mountings and can be accurately positioned. When cam follower 67 is displaced by cam lobe 66, follower 67 contacts one contact switch 68 closing a circuit. The direction of cam rotation determines which circuit will be closed. The direction of the cam 65 rotation is indicative of the direction which the inspection drone 4 is traveling. Cam 65 has one or more cam lobes 66. Cam lobes 66 can be mounted on calibrated wheel 61 to actuate contact switches 68. Auxiliary Switching Figure 11 C Magnetic senders 87 can be mounted on calibrated wheel 61 or main shaft 63. Proximity switches 88 mounted near these revolving senders will close a circuit. Location Visual Display 6 (Fig. 11 C, Fig. 8 and Fig. 10) A mechanical mount 59 attaches location visual display module 6 to camcorder housing 7. Visual display module 6 is composed of two subassemblies. A display electronic circuit 76 and a LCD crystal display face 75. The location display electronic circuit transmitter transmits data to display circuit 76 which responds by increasing or decreasing the reading on display face 75. LCD Crystal Display Face 75 (Fig. 11 C) The data on display face 75 is viewed by the camcorder and recorded on the video tape. A reset switch 93 resets the location display to zero to re-establish a datum line. Auxiliary Assembly 78 (Fig. 11 A) Auxiliary equipment can be powered by rotating main shaft 63. A coupling 74 on main shaft 63 provides a connector to attach a rotary encoder 73. Encoders 73 supply various kinds of information based on the characteristics of the rotational rates of main shaft 63. A calibrated wheel 61 is mounted on main shaft 63. A guide groove 69 is machined in the circumference of calibrated wheel 61. Transmitter 5 is aligned by its mechanical mount so that drone guide cable 36 passes over the face of calibrated wheel 61. Cable 36 engages a guide groove 69. Two adjustable cable idlers 62 maintain the alignment of the cable. Cam Assembly 89 (Fig. 11 A) The cam assembly 89 consists of a cam 65 mounted on main shaft 63 and a cam follower 67 mounted on a pivot 70. Cam follower 67 is held on a plain perpendicular to the center line of main shaft 63. Cam follower 67 is engaged by cam lobes 66 regardless of which direction cam 65 rotates. Switch Assembly 71 (Fig. 11 B) A switch assembly 71 is comprised of two contact switches 68 which are activated by physical contact. Contact switches 68 are on adjustable mountings and can be accurately positioned. When cam follower 67 is displaced by cam lobe 66, follower 67 contacts one contact switch 68 closing a circuit. The direction of cam rotation determines which circuit will be closed. The direction of the cam 65 rotation is indicative of the direction which the inspection drone 4 is traveling. Cam 65 has one or more cam lobes 66. Cam lobes 66 can be mounted on calibrated wheel 61 to actuate contact switches 68. Auxiliary Switching Figure 11 C Magnetic senders 87 can be mounted on calibrated wheel 61 or main shaft 63. Proximity switches 88 mounted near these revolving senders will close a circuit. Location Visual Display 6 (Fig. 11 C, Fig. 8 and Fig. 10) A mechanical mount 59 attaches location visual display module 6 to camcorder housing 7. Visual display module 6 is composed of two subassemblies. A display electronic circuit 76 and a LCD crystal display face 75. The location display electronic circuit transmitter transmits data to display circuit 76 which responds by increasing or decreasing the reading on display face 75. LCD Crystal Display Face 75 (Fig. 11 C) The data on display face 75 is viewed by the camcorder and recorded on the video tape. A reset switch 93 resets the location display to zero to re-establish a datum line. Auxiliary Assembly 78 (Fig. 11 A) Auxiliary equipment can be powered by rotating main shaft 63. A coupling 74 on main shaft 63 provides a connector to attach a rotary encoder 73. Encoders 73 supply various kinds of information based on the characteristics of the rotational rates of main shaft 63. Parapet Clamp Assembly Outside Clamp Leg Beam 31 is inserted into beam socket 93 of an outside clamp leg 94. Outside clamp leg 94 has a parapet rest 96, an outside clamp face 97, also a slot 105 and two pin holes 104 for a pin 102. Inside Clamp Leg Beam 31 is inserted into beam socket 93 of inside clamp leg 95. Inside clamp leg 95 has a parapet rest 96, also a slot 105 and two pin holes 104 for a pin 102. At the lower end of inside clamp leg 95 is a clamp compression screw 99. An inside clamp face 98 is mounted on clamp screw 99. Outside clamp leg 94 and inside clamp leg 95 are connected at their upper ends by an adjustable compression bar 100. Compression bar 100 is installed in slots 105 and held in place by pin 102 through pin hole 104. Pins 102 through holes 104 at the parapet level of clamp leg 94 and clamp leg 95 are used to mount an adjustable tension chain on each side of the clamp legs. Camera Dolly Assembly 106 Wheeled camera dolly assembly 106 (Fig. 18) is built on a main chassis 109 which has a front axle bearing 112 and a rear axle bearing 112. A front axle 108 and a rear axle 113 are installed into these bearings 112. Front axle 108 is considerably wider than the main chassis 109 which enables the main chassis 109 to be positioned far to either side of the front axle 108 centerline. Rear axle 113 is the width of main chassis 109 keeping both rear wheels 107 close to main chassis 109. Main chassis 109 (Fig. 18) has a camera post 110 attached near the front of the chassis. Camera post 110 has a camera arm 111 mounted on it by a movable fitting 114. Rotating connector 46 is mounted on the opposite end of camera arm 111. Rotating connector is the mounting point for camcorder house 54, additional fitting can be assembled to mount multiple camcorder housings. Drone location transmitter 5 (Fig. 18) is mounted at the rear of main chassis 109 by mechanical connector 60. Electrical connector 58 runs from location transmitter 5 through chassis 109 and attaches to display electrical circuit 76 mounted on the camcorder house 54 (not shown). Camera Dolly Cable Assembly 23 (Fig. 18) Drawing Fig. 14A illustrates the camera dolly cable assembly layout. The camera dolly is omitted from Fig. 14A so that the cables can be clearly seen. Ground pressure cable 120 is tensioned between parapet attachment 122 and cable winch 121. Cable 120 is placed under as much tension as possible to increase its resistance to being pulled away from the structure's wall. The purpose of cable 120 is to guide the camera dolly in a straight path up the wall. Cable 120 will also be used to hold the dolly firmly against the wall. Drone positioning cable 8 raises or lowers the camera dolly 106 as it makes imaging passes on the structure. Camera dolly 106 is shown in Fig. 14B to illustrate its relationship to the cable assembly. One of the functions of ground pressure cable 120 is to guide camera dolly 106 in a straight path up and down the structure wall. Camera dolly 106 must have an attachment that follows the guide cable 120 and keeps the dolly chassis 106 aligned with the cable. Roller shoe 116 (Fig. 13, Fig. 13A, Fig. 15 and Fig. 16) is such an alignment device. Roller shoe 116 (Fig. 13 and Fig. 13A) is a long, narrow shape with rollers along its bottom. Cable 120 is confined in this narrow shape and runs on hardened steel rollers 124. Each roller 124 has internal bushings and turns on a steel pin 133 pressed into parallel holes 136. Roller shoe 116 is positioned and stabilized by two radius rods 125, one rod on each side of chassis 109 (Fig. 18). These rods are attached to the chassis 106 by pin 130A and to the roller shoe by pin 130B. Ground Pressure Roller shoe 116 and its radius arms are a passive guidance mechanism. It will follow guide cable 120 but it contributes no thrust to force the camera dolly against the structure. Force must be exerted on the roller shoe 116 to lift against ground pressure cable 120. Cable 126 has a cable eye 132 on each of its ends and one end of cable 126 is attached to pin 130B at the roller shoe 116 (Fig. 13A). There are two cable 126 units required, one for each side of chassis 109. Both cables travel upward and over the top of a shive 119 and are attached to a mechanism that, through cable 126, applies force to roller shoe 116. Our camera dolly has two optional force generating mechanisms, one adjustable and one non-adjustable. Drawing Fig. 15 and Fig. 15A illustrate our adjustable ground pressure assembly 115. The adjustability assembly 115 is based on a tumbuckle 128, which tensions a spring 129. Spring 129 has a wire yoke 135 which attaches to both cable 126 which apply a lifting thrust to roller shoe 116. This adjustable system is used for light duty applications where the weight of the camera dolly is supported by positioning cable mount 134. Drawing Fig. 17 and Fig. 17A illustrate the layout of our non-adjustable ground pressure assembly 115. Please note that in the adjustable system the pair of cables 126 travel upward and pass in front of shive 119 and turn rearward. Cable 126 in our non-adjustable system (Fig. 17 and Fig. 17A). Both of these cables pass behind shive 119 and turn forward. Both of the cable 126 are brought together forward of the main chassis 109 and are attached to cable 8 attachment 53. This cable arrangement is a very powerful method of exerting lift on the roller shoe. The full weight of the camera dolly has been converted from a downward force to a horizontal force, thrusting the camera dolly against the wall. Camera Dolly Cable Assembly 123 (Fig. 14A) Camera Dolly 106 is mounted at attachment point 53 to drone positioning cable 8 which supports its weight. A ground pressure cable 120 (Fig. 14A) under tension, guides and applies ground pressure through a ground pressure assembly 115 (Fig. 16 and Fig. 18). Ground Pressure Cable 120 (Fig. 14A) A parapet attachment 122 supports the upper end of ground pressure cable 120. The lower end of cable 120 is attached to cable winch 121. Winch 121 is attached to weight 42 or anchored 44 to an immovable object. Attached to winch 121 is a cable support shive 32 and an umbilical terminator mount 15. Umbilical tee 16 is mounted in mount 15.which attaches the umbilical 2 to cable winch 121. The umbilical 2 bring drone positioning cable 8 to shive 32A. Positioning cable 8 passes under shive 32A and up and over shive 32B. After passing over shive 32B, the cable turns downward to be attached to camera dolly assembly 106 (not shown). This embodiment functions with the power head 1 at ground level. With a simple rearrangement of components, the power head can be at roof level. Ground Pressure Assembly 115 (Fig. 15 and Fig. 17) Ground pressure assembly 115 is a mechanism for exerting pressure against the structure wall by the camera dolly. Camera dolly main chassis 109 has a positioning cable mount 134 and on each side of the chassis (Fig. 16 and Fig. 18) is mounted a cable shive 119. Cable shives 119 support and guide the two lift cables 126 used in the adjustable and the non- adjustable assemblies. A roller shoe 116 (Fig. 15) rides under pressure cable 120 and is stabilized by two radius arms 125. Radius arms 125 are attached to the main chassis by mounting pin 130A and to the roller shoe by mounting pin 130B. Rollershoe 116 (Fig. 15A) has a series of parallel pin holes 136 drilled through both walls of the shoe 116. A roller is positioned in the shoe and a roller pin 133 is installed into the wall of the shoe through the roller and out the other parallel hole. Rollers 124 have internal bearings and are made of hardened steel. Lift cable 126 is a piece of steel cable with a cable eye 132 on both ends. Adjustable Ground Pressure Assembly A cable eye 132 (Fig. 17) is attached to both ends of pin 130B (Fig. 15). Cable 126 passes up in front of shive 119. Shive 119 re-directs cable 126 toward the chassis rear and cable eye 132 engages a yoke 135. A cable 126 is required on both sides of the chassis starting at mounting pin 130B and attaching to yoke 135. Yoke 135 is attached to a tension spring 129 that is attached to a tension adjuster 128. Tension adjuster 128 is attached to the main chassis 109 by an adjuster mount 127. Non-Adjustable Ground Pressure Assembly A cable 126 is attached to each end of mounting pin 130B by engaging cable eye 132. Cable 126 extends upward to the rear of shives 119. Cable 126 passes over the top of shive 119 and turns forward toward the front of the chassis. Both cable eyes 132 are connected to drone positioning cable 8 by attachment 53. Special Accessories / A parapet clam as shown in Fig. XX, jis used in circumstances when standard parapet boom XX is not practical. A screw clamp X locks the parapet between no counter weight. A special wheeled camera dolly Fig. XX is used on inclined surfaces or when high wind conditions exist. Wheeled dolly XX has four wheels, two spread wide apart on the front axle and two wheels close together on the rear axle. The width of the front of the dolly body is narrow compared to the width of the front axle XX. The dolly body can be located to either side of the axle center line to offset the dolly body on the axle. The wheeled dolly XX requires a guide cable XX under tension to hold its wheels against the structure wall. An offset upper cable bracket XX supports the upper end of a guide cable XX. A winch XX which is attached to a weight, or anchored to a solid structure, is attached to the lower end of the guide cable XX. Winch XX is used to apply tension to guide cable XX stabilizing the wheeled dolly XX. The upper guide cable bracket XX has a cable shive XX which guides the dolly lifting cable XX. The lower guide cable XX tensioning winch XX has an umbilical terminator mounting point XX and a cable shive XX which guides the dolly lifting cable XX. A low profile roller sled travels on a tensioned guide cable and centers the main body of the dolly over the guide cable. A cable XX is attached to the roller sled XX and passes up to a cable shive XX and rearward to connect to a wall tension spring XX. Tension spring XX is attached to adjustable rear spring mount XX. The dolly-lifting cable is attached to the main body of the dolly. Dolly-lifting cable XX passes upward and over cable shive XX, then downward passing under the dolly and under cable shive XX before entering umbilical XX. Dolly-lifting cable XX is driven by the power head XX at the opposite end of umbilical XX. Main dolly body XX acts as a chassis connecting the front and rear axles and as a mounting point for the wall tensioning assembly and a mounting point for battery pack XX. A camera post XX is attached to the forward end of dolly body XX. A camera arm XX is mounted on camera post XX by a friction-fit coupling which permits vertical relocation of the arm on the post. Camcorder housing XX is mounted on camera arm XX by rotary fitting XX which is adjustable in transverse angle to the imaged surface. Mechanical fitting XX attaches location transmitter XX to the rear of dolly body XX. Electrical connection XX connects location transmitter XX to location display XX, which is mounted on camcorder housing XX.

Claims: What Is Claimed Is: 1. An apparatus for remote inspection of building facades, comprising: an inspection drone for traversing the building facade, the inspection drone having an imaging device for recording images of the traversed regions of the facade; a support structure for supporting and guiding the inspection drone in a selective path along the building facade; and a position indicating device for indicating the position of the inspection drone relative to one or more predetermined reference points, and recording the respective indicated positions for each of the recorded images of the facade. 2. An apparatus in accordance with claim 1 in which the apparatus further comprises means for assembling a plurality of separate images of the building facade into a single composite 3. An apparatus in accordance with claim 1 in which the support structure for the apparatus further comprises a pressure assembly for biasing the inspection drone against the buildin Όs facade. 4. An apparatus in accordance with claim 3 in which the pressure assembly maintains positive engagement of the inspection drone against a building facade regardless of the angle at which the buildin»g facade extends. 5. A method for remote inspection of a building facade, comprising: providing an imaging device; traversing a plurality of selective regions of the building facade with the imaging device; providing a position indicating device for indicating the position of the imaging device relative to one or more reference points; and continuously recording the location of the imaging device as it traverses the building facade to correlate the images with respective locations. 6. A method in accordance with Claim 5 in which two or more of the recorded images are assembled into a composite image.

Inventors: HICKS WILLIAM, HICKS, WILLIAM
Applicants: HICKS WILLIAM, ROD ABRAMSON, HICKS, WILLIAM
Application year: 1998
Main classification: H04N7
IPC codes: B62D57