Irradiation apparatus

An apparatus for irradiating surfaces includes an electron beam generator for generating a beam of electrons. The beam of electrons exits the electron beam generator through an exit window. A robotic device moves the beam of electrons over the surfaces to irradiate selected regions of the surfaces. The robotic device includes a propulsion system for propelling the robotic device.

BACKGROUND

Personnel working within environments contaminated with hazardous chemical or biological agents typically wear protective suits to prevent direct exposure to the hazardous agents. Since the outer surfaces of the suit can become covered with the hazardous agents during use, the user is in danger of becoming contaminated when the time comes to remove the suit. Therefore, it is apparent that there are instances where the skin and inner clothing of such personnel can come into contact with the hazardous agents. In addition, there may be situations where people not wearing protective clothing find themselves in a contaminated environment and become contaminated with such hazardous agents. Furthermore, rooms and objects such as vehicles, structures, furniture, equipment, etc., can become contaminated.

SUMMARY

The present invention is directed to an apparatus and method for irradiating surfaces which is suitable for decontaminating surfaces, including clothing or the skin on a person, or other living creatures, as well as irradiating and treating rooms and objects such as vehicles, structures, furniture, equipment, etc. The apparatus includes an electron beam generator for generating a beam of electrons. The beam of electrons exits the electron beam generator through an exit window. A robotic device moves the beam of electrons over the surfaces to irradiate selected regions of the surfaces. A propulsion system is included for propelling the robotic device.

In preferred embodiments, the propulsion system includes a first pair of rotatable wheels rotatably fixed and spaced apart from each other along a first axis. The first pair of wheels are rotatably driven. A second pair of rotatable wheels are spaced apart from each other along a second axis transverse to the first axis. The wheels of the second pair are also rotatably driven and each is pivotably mounted and steerable. Each wheel in the first and second pairs of rotatable wheels can be independently driven. In another embodiment, the robotic device can be moved along a track in a fixed path. The robotic device also includes a robotic arm for maneuvering the electron beam generator. The robotic device has a horizontal rotary joint for swinging the robotic arm. The robotic arm includes an upper arm member with a rotary shoulder joint rotatably coupled to the upper arm member for raising and lowering the robotic arm. A lower arm member is rotatably coupled to the upper arm member by a rotary elbow joint. The elbow joint raises and lowers the lower arm member relative to the upper arm member. A bracket is rotatably coupled to the lower arm member by a rotary wrist joint. The wrist joint swings the bracket from side to side. A rotary bracket joint rotatably couples the electron beam generator to the bracket for rotating the electron beam generator. The robotic device is capable of controllably spacing the exit window of the electron beam generator a desired distance away from the surfaces as the electron beam generator is moved over the surfaces. Such spacing can be performed actively and continuously. The electron beam generator is typically hermetically sealed and irradiation of the surfaces can be for purposes including any one of sterilization, decontamination, curing, destroying molecules and facilitating chemical reactions.

By having a propulsion system and a robotic arm, embodiments of the present invention are able to sufficiently maneuver the electron beam generator to irradiate the floor, walls and ceilings of a room. In addition, embodiments of the present invention can maneuver the electron beam generator around objects such as vehicles, structures, furniture, equipment, etc., for irradiating outer surfaces thereof. Such irradiation capabilities can be useful for decontaminating hazardous biological and chemical agents on surfaces of a room or object, as well as curing coatings, paints or inks on such surfaces.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIG. 1, electron beam irradiation or decontamination apparatus10is employed for decontaminating surfaces having hazardous agents thereon and is suitable for decontaminating the clothes and skin of humans, as well as other living creatures. Decontamination apparatus10includes an electron beam generator12for producing a low power beam16of electrons e−which exit the electron beam generator12through an exit window12a. A nozzle assembly14is mounted to electron beam generator12and concentrically surrounds the exit window12a. Nozzle assembly14is provided with an inert low density gas such as helium (He2) from a supply line20. Nozzle assembly14directs a curtain of the gas from outlet14awhich flows in substantially the same direction as the beam16of electrons e−. This produces a volume of low density gas18adjacent to and in front of the exit window12a. Depending upon the flow rate of the gas and the proximity of electron beam generator12to the surface22ato be irradiated, the volume of gas18may extend from the exit window12ato the surface22aas shown, to occupy the space therebetween. The volume of low density gas18increases the range of the beam16of electrons e−and allows the beam16of electrons e−to travel about seven times further than the distance obtainable when traveling through higher density air. Consequently, electron beam generator12can be of a low power, about 60 kV or less, with the electrons e−capable of reaching the surface22ato be irradiated from distances that ordinarily would be too far away.

Often, the surface22ais a person's skin requiring decontamination from hazardous agents such as chemicals or biological agents (bacteria, viruses, etc.). The beam16of electrons e−attacks the hazardous agents and renders them harmless. In the case of hazardous chemicals, the electron beam16converts the hazardous chemicals into harmless substances by causing chemical reactions. In the case of biological agents such as organisms, bacteria or viruses, the electron beam16kills the organisms, bacteria or viruses by disabling or destroying cellular structures. Since the electron beam16has low power of 60 kV or less, the electrons e−penetrate and treat only the outer layer of dead skin22which is about 10 to 40 mm thick. Most x-rays generated are of low power and are also stopped at the outer layer of dead skin22. The electrons e−generated by an electron beam generator12operating at 60 kV or less have enough energy to decontaminate surface22abut do not have enough energy to penetrate into the living epidermis24, so that the living tissue experiences little or no damage. In addition, at such low power, the generation of x-rays is kept to a minimum.

When used for decontaminating living creatures such as people, electron beam generator12is preferably operated at 60 kV or less (usually 50 kV or less), with 40 kV to 50 kV being the typical range. At such voltages, typically the exit window12aof electron beam generator12is positioned a distance “d” of about ¼ to ½ inches away from surface22awith distances “d” of up to about 1 inches sometimes being possible, but more commonly possible when electron beam generator12is operated at about 60 kV. If the volume of gas18was not employed, the exit window12aof electron beam generator12would normally have to be a maximum of about ⅛ inch away from surface22ain order for the beam16of electrons e−to pass through the air to reach surface22awith sufficient energy for decontamination. A distance “d” of ⅛ inch is sometimes not practical for use on living creatures. The reason for this is that some living creatures have some surfaces that include curved and complex structures. Some of these structures have configurations with protrusions or recessed areas which prevent the electron beam generator12from being within ⅛ inches away from portions of the surfaces to be irradiated. Examples of such structures are the ears, nose, between the toes, etc., of some creatures. By having the increased range for the low power beam16of electrons e−, such difficult areas can be irradiated sufficiently for decontamination with little or no tissue damage. In other typical applications, decontamination apparatus10can be used to decontaminate the clothing of a person or the outer surfaces of a protective suit while worn by the user. When decontaminating clothes on a person, the clothes sometimes have wrinkles and folds in the material which form recesses or crevasses. The increased range of the low power beam16of electrons e−allow such crevasses to be sufficiently irradiated for decontamination.

The inert low density gas18in front of the exit window12aalso provides inerting in the region of the beam16of electrons e−to reduce or eliminate the formation of ozone (O3). Ozone is typically formed by the interaction of the beam16of electrons e−with oxygen (O2) in the air and can be harmful if inhaled. Replacing the air in front of the exit window12awith the inert gas18removes oxygen from the region which would have formed ozone.

Typically, electron beam generator12is a compact, hermetically sealed unit and can be similar to those disclosed in U.S. Pat. No. 5,962,995, U.S. patent application Ser. No. 09/349,592, filed Jul. 9, 1999, and U.S. patent application Ser. No. 09/209,024, filed Dec. 10, 1998, the contents of which are incorporated herein by reference in their entirety. Electron beam generator12is commonly in the range of about two inches in diameter and six to eight inches long for units operating in the range 40 kV to 60 kV. Alternatively, other suitable electron beam generators can be employed. Although nozzle assembly14is shown inFIG. 1to surround the exit window12aof electron beam generator12, alternatively, the nozzle assembly14can be positioned adjacent to the electron beam generator12. In addition, nozzle assembly14does not have to direct the low density gas18in the same direction as the electron beam16but instead can direct the gas18perpendicularly or at an angle to the electron beam66.

In order to irradiate the entire body24of a person, decontamination apparatus10can be part of a decontamination apparatus30where the decontamination apparatus10forms an electron beam generator irradiation unit15that is mounted on a robotic arm26, as shown inFIG. 2. The robotic arm26moves decontamination apparatus10around the body24for providing complete irradiation coverage. Additionally, more than one decontamination apparatus10can be mounted to robotic arm26, as shown, to form the electron beam generator irradiation unit15in order to provide a larger irradiation region for obtaining a faster decontamination time. The robotic arm26may rotate around the body24about an axis A while vertically translating the irradiation unit15on a track up and down as shown by arrows28. Typically, irradiation unit15is incrementally translated in the vertical direction after each rotation of robotic arm26around body24until the entire body24is irradiated. The irradiation unit15can also be translated laterally inwardly and outwardly relative to the body24to maintain the desired distance “d” between the exit windows12aof the electron beam generators12and the surfaces of the body24in view that the surfaces of body24have variable distances from robotic arm26. The irradiation unit15can be tilted in order to be properly orientated relative to the changing surfaces of body24. In cases where there is more than one electron beam generator12, the electron beam generators12can be independently translated laterally. The distance “d” can be continuously and actively controlled by a spacing device13(FIG. 1) mounted to each electron beam generator12. In one embodiment, the spacing device13is a proximity sensor which controls the lateral translation of the associated decontamination apparatus10. Although arm26is shown inFIG. 2to rotate about axis A, alternatively, arm26may be stationary while vertically translating irradiation unit15, in which case, the person stands on a rotary table that spins the body24about axis A.

Referring toFIG. 3, decontamination apparatus40is another embodiment of the present invention in which the irradiation unit15is mounted to a conventional type robotic arm32. As with decontamination apparatus30, irradiation unit15can include one or more decontamination apparatuses10. Robotic arm32includes a series of linear and rotating joints which allow the irradiation unit15to move over the surfaces of a person's body24for decontamination purposes. The robotic arm32shown inFIG. 3includes a waist joint36rotatably mounted to a fixed base34about a vertical axis38for rotation in the direction of arrows38a. A vertical post42extending along vertical axis38is mounted to waist joint36. A shoulder joint44is mounted to post42for linearly translating vertically up and down the post42in the direction of arrows44a. An arm48is mounted to the shoulder joint44for linearly translating laterally relative to shoulder joint44within portion46in the direction of arrows46a. Arm48includes a first rotational joint52for rotation about axis50in the direction of arrows50aand a second rotational joint54for rotation in the direction of arrows54aabout an axis that is perpendicular to axis50. Irradiation unit15is distally mounted to arm48beyond joint54. Waist joint36laterally pivots arm48and shoulder joint44raises and lowers arm48relative to body24. Arm48translates irradiation unit15towards and away from body24within portion46of shoulder joint44. Joints52and54pivot irradiation unit15relative to body24.

As with decontamination apparatus30, irradiation unit15is continuously and actively maintained at the desired distance “d” from the surfaces of body24by spacing device13while being maneuvered around body24. If desired, the body24can stand on a rotary table56which rotates body24about axis A in the direction of arrows56a. If a rotary table56is employed, the decontamination process can be accomplished more quickly. It is understood that the robotic arm32shown inFIG. 3is an example of a robotic arm that can be employed, and that many other suitable variations or alternative robotic arms are possible. For example, joints can be added to or omitted from robotic arm32. One such example is replacing shoulder joint44with a rotating joint that raises and lowers arm48. Another example is combining joints52and54into a single joint. In addition, another linear joint for movement orthogonal to those depicted by arrows46aand44acan be added.

Referring toFIG. 4, decontamination apparatus10can include a mechanical spacing device17that includes one or more protrusions11mounted to the electron beam generator12. Typically, the protrusions11are fixed to the nozzle assembly14and continuously and actively provide the proper distance “d” between the exit window12aand the surface22aby contacting the surface22a. The distal ends of protrusions11can be curved as shown or can be straight. The mechanical spacing device17can be employed with a robotic arm26/32or can be employed when decontamination apparatus10is used as a hand held device. When mounted to a robotic arm26/32, the mechanical spacing device17can also include pressure sensing elements11aassociated with the protrusions11for controlling the force at which the robotic arm presses the protrusions11against the surface22a. InFIG. 4, the sensing elements11aare shown to be fixed between protrusions11and nozzle assembly14to sense shear forces therebetween. Alternatively, protrusions11can press axially against a set of sensing elements11bfor sensing axial force. In addition, protrusions11can be spring load either vertically or pivotally for tripping a limit switch. Although multiple protrusions11have been shown inFIG. 4to form spacing device17, alternatively, spacing device17can also be formed by a single annular projection or hood. The hood may include slots or openings therethrough to allow the escape of gases.

When employed as a hand held device, decontamination apparatus10may include radiation shields for added protection and more than one decontamination apparatus10can be employed to form the irradiation unit15. It is also understood if hand held, that decontamination apparatus10can employ either the mechanical spacing device17or the spacing device13depicted inFIG. 1, where the spacing device13is a proximity sensor. The proximity sensor can be connected to a distance indication system such as a speaker and/or an indicator light to provide an audible tone and/or a visible light when the proper distance “d” is obtained. The distance indication system can also include a distance meter or distance readout. The spacing devices13/17along with any associated equipment can be considered a spacing system.

Referring toFIGS. 5 and 6, decontamination apparatus60is still another embodiment of the present invention. Decontamination apparatus60includes an enclosure58containing a series of decontamination apparatuses10that are arranged to provide substantially uninterrupted electron beam coverage from the multiple surfaces of a body24standing within enclosure58. Many of the surfaces of body24face on different directions. Some of the surfaces of body24are curved or angled relative to each other, or are on opposite sides of body24, etc. A first lateral series of decontamination apparatuses10are arranged abutting each other and facing inwardly. This forms an enclosed lateral wall of electron beam generators12to generate a substantially continuous laterally directed wall or curtain of electron beams16inwardly into the enclosure58from substantially all sides or directions. In addition, a second vertical series of abutting decontamination apparatuses10are positioned at the bottom and the top of enclosure58for forming a floor and ceiling of electron beam generators12to generate a substantially continuous vertical shower of electron beams from axial ends of enclosure58. Each decontamination apparatus10may be individually moveable inwardly and outwardly relative to the space within enclosure58for providing the proper distance “d” between the exit windows12aof the electron beam generators12and the surfaces of a body24. Spacing devices13or17can be employed for controlling the distance “d”. Decontamination apparatus60is able to provide simultaneous irradiation of the surfaces of the entire body24from multiple directions, thereby providing fast or rapid decontamination.

In some cases, irradiation can be sequentially performed by decontamination apparatus60where only a portion of the electron beam generators12are irradiating at a given time. For example, the irradiation can be started at one part of the body24, such as the head, and then the remaining electron beam generators12incrementally activated until the entire body24is irradiated. This may be helpful to prevent claustrophobia where only portions of the electron beam generators12are moved into position for irradiation at a given time. The electron beam generators12could be moved into position to irradiate as much as ¼ to ½ of the body24at the same time.

Entry into enclosure58is provide by a door62having a handle66and hinges64. Alternatively, other suitable doors can be employed. For example, the longitudinal axis of enclosure58can be horizontal so that the door is at one axial end and the body24is inserted therein while lying horizontally. In such a design, a horizontal support may be provided for supporting the body24without blocking the electron beams16. Although enclosure58is shown to be cylindrical in shape, alternatively, enclosure58may have a cross section that is rectangular, oval, polygonal, or combinations thereof. The enclosure58can also have an interior shape closely resembling a human shape. In addition, it is understood that the number of electron beam generators12employed is determined by the size of enclosure58and the size of the individual electron beam generators12. Furthermore, decontamination apparatus60can be configured so that only a portion of body24is simultaneously irradiated, for example, half the body24, which then is turned for irradiation of the other half. A rotary table56(FIG. 3) can be employed.

In the present invention, since the electron beam generators12can be made small in size, in some cases the electron beam generators12are able to maneuver close enough to the surfaces to be irradiated to provide sufficient decontamination without the use of the low density gas18and without damaging living tissue when irradiating skin. Although irradiation through air when an inert gas is not supplied results in the formation of ozone, if irradiation of a body24of a person can be performed within about 20 seconds, the person can hold his or her breath during the irradiation process to avoid inhalation of ozone. In other situations where the electron beam generators12are positioned closely to the surfaces to be irradiated (about ⅛ inches), a nozzle assembly14can be used to direct inert gases that are not necessarily low density for inerting purposes, such as nitrogen, argon, etc., to reduce or eliminate the formation of ozone.

If the irradiation time takes longer than about 20 seconds, both when an inert gas is supplied or when irradiating through the air, the person can be provided with a supply of breathable air or oxygen68through an air/oxygen supply system70, such as a nozzle assembly, from an air or oxygen supply as shown inFIG. 7. A gas removal or exhaust system74, for example, a suction nozzle, can be provided for removing gases72undesirable for inhalation, such as the supplied inert gases and/or ozone. A blower system can also be employed as the gas removal system. The air/oxygen supply system70and the gas removal system74are either positioned to not interfere with the irradiation process or are movable. In some cases, the person may have to hold his/her breath initially until the head is decontaminated.

Referring toFIG. 8, electron beam irradiation or decontamination apparatus80is yet another embodiment of the present invention which differs from apparatus10depicted inFIG. 1in that apparatus80includes a gas removal vacuum assembly76concentrically surrounding the exit window12aof the electron beam generator12and mounted thereto. Gases including any generated ozone are drawn into the inlet76aof vacuum assembly76from the region adjacent to exit window12a, between surface22aand exit window12a, and then out vacuum line78. This eliminates or reduces the amount of ozone in the region of apparatus80. In some cases, the pressure in front of exit window12acan be lowered, thereby increasing the range of the beam16of electrons e−.

Referring toFIG. 9, electron beam irradiation or decontamination apparatus82is another embodiment of the present invention which differs from apparatus10depicted inFIG. 4in that apparatus82includes the vacuum assembly76ofFIG. 8. Typically, spacing device17is a hood or shroud with a single annular protrusion11which allows a greater decrease of the pressure in front of exit window12a. This further increases the range of the beam16of electrons e−, thereby increasing the distance “d” at which effective decontamination can be obtained. The protrusion11can be made with openings or slots therethrough to allow some flow of gases. Apparatuses80and82are typically employed without supplying inerting gases, but in some cases, providing inert gases can be desirable. The gas removal or exhaust arrangements described above as well as the supply of inerting gases can be among other things, referred to as ozone reduction systems.

Although the present invention decontamination apparatuses have been described for decontaminating clothing and living creatures, the decontamination apparatuses may be used for any suitable irradiation application. Such applications may include the irradiation of non-living objects, materials or substances for sterilization, curing, or facilitating chemical reactions. Furthermore, electron beam generators12having power higher than 60 kV or lower than 40 kV may be used. In cases where non-living objects, materials or substances are to be irradiated, electron beam generators12can operate well above 60 kV, for example, 125 kV or greater. The low density gas18, when used, allows the electron beam generators12to be positioned farther away from the objects, materials or substances than normally possible without the low density gas. Such increased range of the beam16of electrons e−also permits deeper penetration into the objects, materials or substances as well as more thorough irradiation of complex geometries. There may be situations when irradiating non-living objects, materials or substances in which supplying other inert gases is desirable. Also, the removal of gases with a gas removal system may be desirable.

Referring toFIG. 10, mobile robotic irradiation apparatus90is another embodiment of the present invention. Apparatus 90 includes a mobile robot91having a maneuverable arm99for maneuvering an electron beam generator12mounted at the distal end for irradiating surfaces with a beam16of electrons e−. Surfaces can be irradiated for purposes including sterilization, decontamination, curing, destroying molecules, facilitating chemical reactions, etc. Any of the spacing devices described earlier can be included for spacing the exit window12athe proper distance from the surfaces to be irradiated and, depending upon the situation at hand, a gas supply system may or may not be employed. The exit window12acan be made rectangular or square, as shown inFIG. 12, for allowing positioning within corners such as in a room. The housing of electron generator12in the region of the exit window12ais shown to be flared outwardly in a rectangular or square manner. An exit window that is about 4 inches by 4 inches is typically suitable for most applications, although larger, smaller, or round exit windows12amay be suitable in particular instances. When irradiating nonliving surfaces, a higher power beam16of electrons e−can be generated than when irradiating living surfaces. Such higher power beams16of electrons e−allow the exit window12aof electron beam generator12to be spaced a distance “d” that is farther away than when employing the lower power beams16of electrons e−.

The mobile robot91includes base92having a propulsion system110for steerably propelling the robot91and irradiation apparatus90. The propulsion system110typically includes a series of wheels114L/114R and118F/118B (FIGS. 18–20). A turret94is rotatably mounted to the base92by a rotary waist joint108. The waist joint108provides 360° of horizontal rotary motion of the turret94about a vertical axis93ain the direction of arrows93for swinging maneuverable arm99horizontally. The maneuverable arm99has an upper arm member96which is rotatably mounted to turret94by a rotary shoulder joint98. The shoulder joint98provides about 180° of rotary motion of the upper arm member96and maneuverable arm99about a horizontal axis98ain the direction of arrows95for raising and lowering the maneuverable arm99. A slotted recess106having an upper portion106ain the turret94and a lower portion106bin the base92allow the upper arm member96to be lowered therein for increased range of motion, especially when angling arm member96downwardly. A lower arm member100is rotatably mounted to upper arm member96by a rotary elbow joint102. The elbow joint102provides about 270° of rotary motion of the lower arm member100about a horizontal axis102ain the direction of arrows97to raise and lower or swing arm member100. A cage or bracket103which houses or supports electron beam generator12is rotatably mounted to the lower arm member100by a rotary wrist joint104. The wrist joint104provides about 270° of side to side rotary swinging motion about axis104ain the direction of arrows99. The orientation of axis104achanges with the position of shoulder joint98and elbow joint102. The electron beam generator12is rotatably connected to cage or bracket103by a rotary cage or bracket joint105. Rotary cage joint105provides 360° of rotary or spinning motion of electron beam generator12about axis105ain the direction of arrows107. This allows the exit window12aof electron beam generator12to be appropriately positioned, such as in a corner. The propulsion system110, waist joint108, shoulder joint98, elbow joint102, wrist joint104, and cage joint105are typically driven by drive motors (for example, drive motors121ain propulsion system110,FIG. 18), and allow the electron beam generator12to be moved or positioned for irradiating two-dimensional and three-dimensional surfaces. The drive motors for the robot91and propulsion system110are typically rotary servo or stepper motors which are connected to and controlled by a computer, usually housed in the base92.

When the surfaces to be irradiated are larger than the size of the beam16of electrons e−, the electron beam generator12and beam16of electrons e−are moved over the surfaces in a progressive overlapping manner to incrementally irradiate the surfaces. The movement of electron beam generator12and the beam16of electrons e−can be preprogramed or can be continuously and actively determined in real time. The irradiation can be employed to cure coatings, paints and inks, kill bacteria and viruses, convert hazardous substances into non-hazardous materials, initiate or aid chemical reactions, etc.

For example, referring toFIG. 11, irradiation apparatus90is shown positioned within a room112having a floor112a, walls112band ceiling112cwith the maneuverable arm99pivoted about shoulder joint98to be angled downwardly. Maneuverable arm99is also bent at the elbow joint102to position the electron beam generator12in a vertical position in close proximity to the floor112a. In such a position, the electron beam generator12is able to irradiate the surfaces of the floor112a, for example, for sterilization or decontamination purposes. The electron beam generator12is also shown rotated about rotary joint105to orient exit window12afor irradiating the corner of room112. The electron beam generator12can be moved over the floor112aby moving the robot91with propulsion system110, by moving maneuverable arm99, or a combination of the two. The distance “d” between exit window12aand the surfaces to be irradiated can be continuously and actively controlled by a spacing device, when employed. By moving the electron beam generator12back and forth over the floor112ain successive passes so that the coverage of the beam16of electrons e−from each pass slightly overlaps each other, continuous irradiation coverage of the floor112aor desired regions thereof by the beam16of electrons e−can be obtained in increments. In some situations, irradiation of only a selected region or regions may be desired. If electron beam generator12is irradiating surfaces while robot91is propelled by propulsion system110, maneuverable arm99may make slight movements to compensate for irregularities in the surface of floor112awhich can cause tilting of the robot91and/or vary the distance of the electron beam generator12from the floor112a.

Referring toFIG. 12, irradiation apparatus90is shown positioned for irradiating vertical surfaces such as surfaces of a wall112b. When irradiating the lower portions of vertical surfaces, the maneuverable arm99can be pivoted downwardly at shoulder joint98, bent at elbow joint102so that lower arm member100is positioned horizontally, and depending upon the position of robot91or the surface to be irradiated, the electron beam generator12can be pivoted about wrist joint104as shown. Referring toFIG. 13, pivoting the wrist joint104allows electron beam generator12to irradiate surfaces of a wall112bin the corner where two walls112bcome together by positioning robot91away from the adjoining wall112b. In addition, electron beam generator12is rotated about axis105ato orient the exit window12ain the proper orientation for positioning in the corner. When irradiating the corner between walls112b, the irradiation apparatus90can be first positioned as shown inFIG. 12to start at the bottom and then the upper arm member96is pivoted upwardly to irradiate the wall112bin an upwardly moving direction. The elbow joint102can be pivoted simultaneously to maintain electron generator12in a straight vertical path. When in the upper position, the maneuverable arm99is pivoted upwardly about shoulder joint98with the elbow joint102being bent as shown inFIG. 14. If needed, waist joint108can be pivoted. In addition, the position of robot91can be adjusted by propulsion system110during irradiation. Alternatively, the direction of irradiation can be from top to bottom. When irradiating upper surfaces of wall112baway from the corner, the wrist joint104does not need to be bent as shown inFIG. 15. The wall surfaces112b, or desired regions thereof, are typically irradiated with vertical or horizontal movement of electron beam generator12or combinations thereof. In addition, slanted or arched movement can be employed.

FIG. 16depicts irradiation apparatus90positioned for irradiating downwardly facing upper surfaces, such as a ceiling112c(FIG. 11). Maneuverable arm99is pivoted in an upwardly angled or pointed manner about shoulder joint and elbow joint102can be bent to vertically orient electron beam generator12, depending upon the ceiling height. The robot91is moved relative to ceiling112cto irradiate the ceiling112cor desired regions thereof with electron beam generator12. Maneuverable arm99may also require movement, with joints98,102,104,105and108pivoting when necessary.

Referring toFIG. 17, in addition to irradiating interior surfaces of a room112, irradiation apparatus90can move electron beam generator12around an object115such as a vehicle, structure, furniture, equipment, etc., for irradiating exterior surfaces thereof with a beam16of electrons e−. The electron beam generator12is moved around object115or desired regions thereof by moving robot91around object115as well as manipulating maneuverable arm91. This allows irradiation of large or irregularly shaped objects115that cannot fit within a self contained irradiation unit. Examples of such irradiation can be the sterilization/decontamination of object115or the curing of coatings thereon.

Referring toFIGS. 18–21, the propulsion system110of robot91in one embodiment includes a first pair of drive wheels having a right drive wheel114R and a left drive wheel114L which are rotatably mounted or fixed along a common horizontal axis116a(FIG. 19) on opposite sides of base92. Each drive wheel114R/114L is independent from the other and can be driven in the direction of arrows119(FIG. 18) in unison or independently driven in both speed and direction. A second pair of steerable wheels having a front steerable drive wheel118F and a back steerable drive wheel118B are rotatably mounted along respective horizontal axes120F and120B on opposite sides of base92between wheels114R/114L. Each steerable drive wheel118F/118B is independent from the other and can be driven in the direction of arrows119(FIG. 18) in unison, or independently driven in both speed and direction relative to each other as well as drive wheels114R/114L. Each steerable drive wheel118F and118B is also pivotably mounted along respective vertical axes112F and122B (FIG. 18) allowing each steerable drive wheel118F/118B to be rotated or pivoted in the direction of arrows117to provide steering for robot91. The steerable drive wheels118F/1118B can be steered in the same direction in unison or independently steered in different directions (FIG. 20). In addition, the vertical axes112F/122B are positioned along a common horizontal axis116bwhich is positioned midway between wheels114R/114L and is perpendicular to axis116a. The drive wheels114R,114L,120F and120B are, in one embodiment, positioned equidistant from each other as shown. Each drive wheel114R,114L,120F and120B is coupled to and independently driven by a respective drive motor121afor providing rotational motion in the direction of arrows119. In addition, drive wheels120F and120B are independently coupled to and pivotably rotated or steered about axes122F/122B in the direction of arrows117by respective drive motors121b.

In use, referring toFIG. 19, in order to obtain movement in a straight forward direction as shown by arrow124, the steerable drive wheels118F and118B of propulsion system110are first aligned in the same direction as drive wheels114R/114L. The drive wheels114R,114L,118F and118B are then equally driven in unison in the same forward direction towards the front F of robot91, resulting in the straight movement of robot91in the direction of arrow124. Driving wheels114R,114L,118F and118B in the opposite direction towards the back B of robot91would produce movement of robot91in a straight backward direction.

Referring toFIG. 20, to obtain an arched turn in the right forward direction as shown by arrow126, the front steerable drive wheel118F is turned about axis122F to the right and at an angle in the direction of the turn, and the back steerable drive wheel118bis turned about axis122B to the left or in the opposite direction, but at an angle of equal amount, as shown. The steerable drive wheels118F/118B are each driven forward toward the front F of robot91at the same rate while the right drive wheel114R is driven forward at a lesser rate and the left drive wheel114L is driven forward at a greater rate. The difference in the rate that each drive wheel114R,114L,118F and118B is driven relative to each other is in proportion to the difference in the turning radius of each particular drive wheel when a turn is made. When making a turn to the right, the drive wheels118F/118B have a bigger turning radius than drive wheel114R and have to be driven at a greater rate in order to travel a greater distance in the same amount of time. In addition, drive wheel114L has an even bigger turning radius than drive wheels118F/118B when making the turn to the right. To make a left forward turn, the steerable front drive wheel118F is turned to the left and the back steerable drive wheel118B is turned to the right. When the drive wheels114R,114L,118F and118B are driven, drive wheels118F/118B are driven at the same rate while the left drive wheel114L is driven forward at a lesser rate and the right drive wheel114R is driven forward at a greater rate, with the radius of turn being in the opposite direction. A smaller turning radius is obtained by turning the steerable drive wheels118F/118bat greater angles while a larger turning radius is obtained by turning steerable drive wheels118F/118B at lesser angles.

To make a backward arched turn to the right, the steerable drive wheels118F/118B are positioned as shown inFIG. 20but the drive wheels114R,114L,118F and118B are driven in the backward direction toward the back B of robot91. To make a backward arched turn to the left, the steerable drive wheels118F/1118B are positioned in a similar manner as described for making a left forward turn, but the drive wheels114R,114L,118F and118B are driven in the backward direction. The rate of the rotation of drive wheels114R,114L,118F and118B relative to each other, as in forward arched turns, is proportional to the turning radius of each drive wheel.

Referring toFIG. 21, robot91can be rotated by propulsion system110to the right or clockwise in the direction of arrow128while remaining in the same location. This is accomplished by turning the steerable drive wheels118F/118B about axes122F/122B to be perpendicular to drive wheels114R/114L in order to have perpendicular directions of rotation. The drive wheels114R,114L,118F and118B are then driven in unison at the same rate, with drive wheel114R being rotated towards the back B of robot91, drive wheel114L being rotated in the opposite direction towards the front F, drive wheel118F being rotated in the direction towards the right side R of robot91, and drive wheel118B being rotated in the opposite direction towards the left side L. The robot91can be rotated a limited amount or can spin in place. In order to rotate in the counterclockwise direction or to the left, the drive wheels114R,114L,118F and118B are rotated in the opposite direction to that described for clockwise rotation.

The embodiment of the propulsion system110depicted inFIGS. 18–21provides robot91and irradiation apparatus90with the ability to make tight radius turns as well as to rotate the robot91while remaining in a stationary location. Consequently, by linking together the motions shown inFIGS. 19–21and described above, the irradiation apparatus90is able to maneuver within most any room112, or around most any object115, for positioning maneuvering arm99in the proper position to provide continuous irradiation coverage with electron beam generator12. The cylindrical shape of the base92also maximizes the maneuverability of robot91as well as the ability to operate in areas with limited space. Although all the drive wheels114R,114L,118F and118B are preferably driven in order to obtain the best maneuverability, alternatively, in some embodiments, only drive wheels114R/114L are driven. In other embodiments, only drive wheels118F/118B are driven. In addition, various wheels114R,114L,118F and118B can be intermittently driven or intermittently serve as idler wheels. In embodiments where not all of the wheels are driven, the robot91typically has to move before being able to initiate a turn, while if all wheels are driven, no initial motion is required. As a result, the embodiments of propulsion system110which drive all the wheels114R,114L,118F and118B have increased maneuverability, which is desirable when maneuvering within a room112or around an object115. Although the drive wheels114R,114L,118F and118B are preferably the same distance apart from each other as shown, alternatively, some of the drive wheels can be positioned closer together than others, depending upon the situation at hand.

Referring toFIG. 22, mobile robotic irradiation apparatus130is another embodiment of the present invention which differs from irradiation apparatus90in that robot111has a turret134rotatably mounted to a base132about waist joint108with a vertical post136extending upwardly along axis93a. A shoulder member138is slidably mounted to post136by a linear sliding joint136aallowing vertical movement of shoulder member138up and down in the direction of arrows137. Maneuverable arm140is rotatably mounted to shoulder member138at shoulder joint98. Maneuverable arm140includes an upper arm member96having a first portion96aand a second portion96b. The second portion96bis slidably mounted within and to the first portion96aby a linear sliding joint96callowing linear extension and retraction of the second portion96bin the direction of arrows101. The two linear sliding joints136aand96cprovide two additional degrees of movement than found in irradiation apparatus90, allowing additional maneuverability. The joints of robot111can be driven by rotary drive motors such as described for robot91. However, in some embodiments, the sliding joints136aand96ccan be driven by linear motors.

In addition, irradiation apparatus130can include one or both of vision systems142and144shown located on base132and electron beam generator12. The vision systems142/144can be employed for visually guiding the robot111and electron beam generator12while being moved and during the irradiation process. The vision systems142/144can also be employed for measuring a room112or object115to be irradiated for determining the manner in which irradiation is to be accomplished. The path at which the electron beam generator12is moved over the surfaces can be preprogrammed or can be continuously calculated. Alternatively, vision systems142/144can be employed for aiding in remotely controlling and operating irradiation apparatus130from a remote position. In some cases, non-vision sensing systems can also be included. Irradiation apparatus90can also be constructed with such features. Irradiation apparatus130, as well as irradiation apparatus90, can be employed for irradiating living creatures such as a human24as shown, as well as a room112or object115. When irradiating living creatures, an irradiation or decontamination apparatus such as designated10,80and82inFIGS. 1,4,8and9can be employed. Gas supply and/or removal systems can be included as well as spacing devices or systems. For some applications, rotary and sliding joints can be added or omitted.

Referring toFIG. 23, mobile robotic irradiation apparatus150is another embodiment of the present invention which differs from irradiation apparatus90in that the mobile robot91does not have propulsion system110but instead is driven in a fixed path on a track152in the direction of arrows154with a simple two-directional drive or propulsion system. The track152can be circular as shown for moving robot91into position for irradiating surfaces with a beam16of electrons e−from electron beam generator12, for example, an object115, as shown. Surfaces outside of track152can also be irradiated, for example, an object115. In another embodiment, the base92of mobile robot91can be fixed to track152with track152being movable and acting as the drive or propulsion system for moving robot91along a fixed path. Such a movable track152can be a rotary table. Although track152is shown to be circular, track152can be linear or have curved and linear portions, depending upon the situation at hand. In addition, although robot91is shown driven on track152, alternatively, robot111can be substituted for robot91. The track152can be positioned at ground or floor level, or be elevated such as overhead. When track152is overhead, robot91or111can be positioned to hang downwardly from track152. Vision systems, spacing devices or systems, and gas supply and/or removal systems can be included depending upon the situation at hand.

For example, although propulsion system110has been shown with drive wheels, the wheels can be replaced with tractor treads for operation on uneven surfaces, such as outdoors. When employed outdoors, the present invention can irradiate ground surfaces including paved surfaces. In addition, although the electron beam generator12typically provides a wide beam16, alternatively, a thin electron beam can be generated that is scanned back and forth. It is understood that features of the different embodiments described can be combined or omitted. Furthermore, although the mobile robotic irradiation apparatuses have been shown to maneuver one electron beam generator12, it is understood that in some applications more than one electron beam generator12can be maneuvered.