WO2014081573A1

WO2014081573A1 - Tool structure for changing large wheels of a vehicle

Info

Publication number: WO2014081573A1
Application number: PCT/US2013/068681
Authority: WO
Inventors: Jeremy NEWKIRK; William John EAKINS; Thomas Fuhlbrigge; Harald Josef STAAB; Carlos Martinez; Gregory Rossano; Remus Boca
Original assignee: ABB Technology AG
Current assignee: ABB Technology AG
Priority date: 2012-11-20
Filing date: 2013-11-06
Publication date: 2014-05-30
Anticipated expiration: 2015-05-20

Abstract

A tool structure is provided for servicing a wheel assembly securable to a hub of a vehicle. The tool structure includes rigid frame structure constructed and arranged to receive the wheel assembly in a supported manner at a front portion thereof. A rigid platform structure is constructed and arranged to be in a fixed position in relation to the vehicle while servicing the wheel assembly. Linear actuators couple the frame structure to the platform structure so that the frame structure can be oriented and positioned in a plurality of degrees of freedom with respect to the platform structure to position the wheel assembly with respect to the hub of the vehicle.

Description

TOOL STRUCTURE FOR CHANGING LARGE WHEELS OF A VEHICLE

[0001] FIELD

[0002] The invention relates to changing large wheels of an extremely large vehicle and, more particularly, to structure and methods for assembly and disassembly of a vehicle's large wheels.

[0003] BACKGROUND

[0004] Large wheels of large vehicles at times need changing at the worksite. An example of a large wheel is the wheel of a mining truck having tires approximately four or more meters in diameter mounted to a hub of a the vehicle by a large number of bolts or nuts (e.g., more than 70 for large mining trucks). The wheel has to be fine positioned very accurately to be centered with the hub and to match all bolts or bolt holes at the same time. Currently, the wheel changing process for these large wheels is a manual operation using wheel handlers.

[0005] These conventional wheel handlers allow motion in less than three directions and three orientations. They are usually mounted to a wheel loader or a large forklift truck to make use of the driving, steering, and lifting capabilities of these machines. These conventional wheel handlers are configured like a caliper or tong, grabbing the tire from the left and right sides. In particular for assembly, the wheel has to be fine-positioned with less than +/- 1 mm tolerance in the three directions and essentially no tolerance in the three orientations. This fine-positioning of the wheel is very difficult with conventional wheel handlers, even for very skilled operators. Usually the fine-positioning is done by the driver who also controls the wheel handler. Since the driver is not close to the hub and his view to the hub is obstructed by parts of the vehicle (e.g., forklift boom) and the wheel handler itself, the driver needs another person close to the hub to guide him with hand signals. This person is exposed to a severe hazard if the wheel breaks loose from the wheel handler, if there is some uncontrolled movement of the wheel loader or the wheel handler, or in the event that the tire ruptures due to tire damage and/or excess pressure.

Thus, there is a need to provide a tool structure for safe and accurate wheel changing operations.

[0007] BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The invention will be better understood from the following detailed description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings, wherein like reference numerals refer to like parts, in which:

[0009] FIG. 1 is a view of tool structure for changing large vehicle wheel assemblies, in accordance with an embodiment.

[0010] FIG. 2 is a view of a robot of the tool structure of FIG. 1 with a pneumatic wrench for engaging fasteners securing a wheel.

[0011] FIG. 3 is a screen shot taken by a camera on the robot of the tool structure of

FIG. 1 , locating bolt holes of a rim of a wheel.

[0012] FIG. 4 is a side view of tool structure for changing large vehicle wheel assemblies, in accordance with a second embodiment.

[0013] FIG. 5 is a perspective view of the tool structure of FIG. 4. [0014] FIG. 6 is a front view of the tool structure of FIG. 4. [0015] FIG. 7 is a perspective view of the tool structure of FIG. 4 shown carrying a tire.

FIG. 8 is a side view of tool structure for changing large vehicle wheel assemblies, in accordance with a third embodiment, shown carrying a tire.

[0017] FIG. 9 is a front view of the tool structure of FIG. 8.

[0018] FIG. 10 is a side view of tool structure for changing large vehicle wheel assemblies, in accordance with a fourth embodiment, shown carrying a wheel assembly.

[0019] FIG. 1 1 is a view of the tool structure with wheel assembly of FIG. 10, shown in an extended position.

[0020] FIG. 12 is a view of the tool structure of FIG. 10 shown with an optional operator pedestal and rollers.

[0021] FIG. 13 is a view of the tool structure of FIG. 10 shown attached to a wheel loader vehicle.

[0022] FIG. 14 is a bottom view of a tool structure having pairs of rollers on platform structure thereof.

[0023] FIG. 15 is a side view of a tool structure with another embodiment of a rigid extension to securely hold the wheel assembly at the inside portion thereof.

[0024] FIG. 16 is a view of an embodiment of the tool structure mounted to a wheel loader and shown in position to change a wheel assembly of a vehicle.

[0025] FIG. 17 is a side view of the tool structure showing fence structure on the frame structure which prevents a person from accidentally entering the interior of the frame structure where robots or other moving mechanisms are located.

[0026] FIG. 18 is an example screen from a Human Machine Interface (HMI) showing how the user can select a pre-existing pattern for fastening nuts and bolts.

[0027] FIG. 19 is another example screen from the HMI showing how the user can define a custom pattern for fastening nuts and bolts.

[0028] FIG. 20 is another example screen from the HMI which displays the robot's current X, Y, Z, Rx, Ry, and Rz position/orientation and the snapshot or live image of what one or more of the cameras can see.

[0029] FIG. 21 is another example screen from the HMI which displays which fasteners are being operated on by the robot(s).

[0030] FIG. 22 is another example screen from the HMI which displays status information about the robotic system, such as which devices are active, OK, in a fault state, etc.

[0031] FIG. 23 is another example screen from the HMI which displays status information about the robotic system's digital input and output signals.

[0032] FIG. 24 is fastener storage unit which holds the nuts and bolts that are removed from a wheel assembly or holds the nuts and bolts that will be fastened to hold a wheel assembly in place.

[0033] FIG. 25 is a view of an embodiment of the tool structure showing an adapter to increase a range of wheel assemblies/tires to be received. [0034] DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0035] With reference to FIG. 1 , tool structure for installation or removal of a wheel assembly is shown, generally indicated 10, in accordance with an embodiment of the invention. As used herein, a wheel assembly includes a rim with a tire mounted thereon. The tool structure 10 includes rigid frame structure, generally indicated at 12, including a generally square base 14 in the form of a plate and a rigid extension 16 extending from each corner of a common side 17 of the base 14. The rigid extensions 16 are placed so that a large tire (e.g., 4 meters in diameter) of a wheel assembly, generally indicated at 27, to be serviced can be engaged by the members 16 to be held stably. The rigid extensions 16 can be configured to be adjustable to accommodate tires of varying diameters. One or more rigid extensions 16 may be used for engaging the wheel assembly 27. As best shown in FIG. 15, the wheel assembly 27 includes a tire I 32 mounted on a rim 33. One or more rigid extensions 16 can either engage the inner surface of the wheel 32 (FIG. 15) or the tread portion of the tire 32 (FIG. 16). One or more of the rigid extensions 16 may be actuated to engage the wheel assembly 27. This actuation may also be used to translate or rotate the wheel assembly 27. The translation would be parallel to the plane defined by the base plate 14. The rotation would be along an axis A (FIG. 16) that is perpendicular to the plane of the base plate 14, approximately located at the center of the plate. For example, in the case of the four rigid extensions 16 shown in FIG. 1 , the actuation of the rigid extensions 16 could be coordinated to allow manipulation of the wheel assembly 27 once it is firmly grasped.

[0036] One or more rigid extensions 16 may include at least one roller 18 or low friction surface for engaging a tread portion of the tire 32 to be serviced while permitting the tire and thus the wheel 32 to rotate about its axis. The rollers 18 may be passive to allow the wheel assembly 27 to rotate freely or may be actuated in order to drive the rotation of the wheel assembly 27. The rollers 18 or low friction surfaces may be configured with a profile that draws the wheel assembly 27 toward the base plate 14 (e.g., the rollers 18 have a conical shape with the smaller diameter end facing the base plate 14). Adapters 23 (FIG. 25) may be used with one or more of the rigid extensions 16 to increase the range of wheel or tire diameter the rigid extensions 16 can accommodate to account for wheels/tires of various sizes, that have low/no pressure, are out of round, or are missing sections of tread. The adapter could be as simple as a section of square beam that is secured to the rigid extension. In the case where the rigid extension 16 has one or more rollers 18, the adapter could have one or more rollers to engage the rigid extension's rollers. As shown in FIG. 16, the actuation of a rigid extension 16 so as to move in at least one direction, may be accomplished with a piston style cylinder 15, such as a hydraulic, pneumatic or electric cylinder, attached on one end to the rigid extension 16 and attached on the other end to the base plate 14 or frame structure 12 or 12"'. The rigid extension 16 can be attached to the base plate 14 via a linear slide and the cylinder 15 can push/pull the rigid extension 16 linearly along the slide. As is well known by someone skilled in the art, there are many other methods of accomplishing the motion of the rigid extensions 16. The actuation of the rigid extensions 16 may be accomplished with an input device 13 (e.g. a joystick, FIG.15). In the case of more than one rigid extension 16, the input device would have the capability to allow the operator to drive the rigid extensions 16 independently as well as together using a control scheme. Alternatively, the actuation may be controlled automatically with a computer (e.g., a PLC) and/or with a vision guidance system using camera 35 (FIG. 16). Alternatively, one or more camera could be mounted somewhere else, on the device, such as on the frame structure 12"'. In this case, the computer would be programmed to determine the necessary motion of the rigid extensions to accomplish the desired task. As is well known by someone skilled in the art, position sensors or computer vision may be used as feedback in the automatic actuation of the rigid extensions 16. Feedback from the cameras could also be used by a human operator to assist in manually steering the location of the rigid extensions 16 through an input device, such as 13 (FIG. 15) or a wireless joystick.

[0037] The rigid extensions 16 may have a feature that blocks the wheel assembly 27 from falling out of the grasp, as shown in the upper rigid extensions 16 of FIG. 1 . This could be as simple as plates 21 (FIG. 1 ) that extend beyond the gripping surface and in front of the wheel assembly 27. Another example, in the case of more than one rigid extension, would at least one bar 25 (FIG. 7) that is attached from one rigid extension to another and cross in front of the tire. The rigid extensions 16 may have a fail-safe system to prevent them from moving in the event of a power loss. This is a standard feature on many industrial hydraulic systems.

[0038] Returning to FIG. 1 , the base plate 14 includes a central opening 26 so that the wheel fasteners such as nuts or bolts 30 (FIG. 2) can be reached from within the mechanism for removal or installation of a rim 33 with tire 32 thereon with respect to a vehicle's hub 31 (FIG. 16). FIG. 16 shows a tool structure 10"' adjacent to the hub 31 . The hub 31 has threaded holes 29 for receiving the bolts 30. Alternatively, the hub 31 can include threaded studs and the wheel assembly 27 can be secured to the studs via nuts. As used herein, the term fasteners" includes bolts, studs, nuts, or any other structure that is used to secure a wheel assembly to a hub. Furthermore, the term "hub" may also be used to refer to the final drive "

[0039] Returning to FIG. 1 , the frame structure 12 may also include a mounting structure, generally indicated at 20, preferably for mounting one or more robots 22 thereto. In the embodiment, the mounting structure includes a plurality of support members 24 joined to the frame structure 12 and with some members 24 joined to each other. The robot 22 is preferably an industrial grade robot constructed and arranged to perform the fastener removal and insertion operations. With reference to FIG. 2, the robot 22 is for example a six axis IRB 4600 industrial robot manufactured by ABB and fitted with a tool such as a wrench 34 (e.g., an electric or pneumatic wrench) at end 28 thereof to screw and unscrew the fasteners (e.g., bolts 30 in the embodiment). Thus, to remove the wheel assembly 27, the robot 22 is moved so that the wrench 34 engages and unscrews a bolt secured to the hub 31 . This process is repeated until all bolts 30 are removed. Since the robot 22 is enclosed within the frame structure 12, the frame structure 12 helps maintain the robot 22 in the proper position to screw and unscrew bolts 30 on the wheel assembly 27. The rigid extensions 16 engage the tire 32 to keep the frame structure 12 and the robot 22 in a stable location during the screwing and unscrewing operations.

[0040] As stated above, the robot 22 is preferably a six axis IRB 4600 industrial robot manufactured by ABB. The six degrees of freedom allow the robot to translate and rotate the tool about any axis. The gap between the rim 33 and hub 31 of the inner wheel assembly of a dual wheel assembly axle can be very narrow making it difficult to fit the tool in. There may also be obstructions (e.g. the mounting flange for the outer wheel assembly) preventing the tool from being able to move parallel to the hub to fit the tool into this gap. The six degree of freedom capability of the robot will allow it to move along different paths in order to deliver the tool to the necessary location to reach the fasteners.

[0041] In the embodiment of FIG. 16, the mounting between the robot 22 and the frame structure 12"' could include a mechanism that has one or more degrees of freedom, such as a linear axis or pan and tilt system. Such movement, via hydraulic cylinders 72, may be necessary to allow the robot 22 to reach all the fasteners for the attaching or detaching operation. Such mounting variations can be implemented by someone skilled in the art and are explained more fully below with regard to FIGs. 10-14.

[0042] It can be appreciated that in an alternate embodiment, more than one robot 22 can be attached to the tool structure 10. For example, two robots 22 can be mounted side-by-side. In another example, one robot 22 can be mounted upright and a second robot 22 can be mounted upside-down directly beneath the upright robot. The mounting of the multiple robots 22 can be such that they are in a fixed relationship to each other, or they could be mounted on movable platforms, such as a linear axis, in order to adjust their relationship to one another or improve the robots' reachability. Such mounting variations are implementable by someone skilled in the art.

[0043] In some embodiments, compliance may be desirable to prevent damage and to also assist the tool 34 attaching itself to a fastener. This can be accomplished by mechanical or software means. A mechanical means could include placing a compliant layer, such as rubber, between the robot face plate and the tool 34. A software means could be include programmatically controlling the rigidity of the robot at the joint level or in one or more directions (for example, see ABB's "SoftMove" product,

[0044] http://www05.abb.com/qlobal/scot/scot241 .nsf/veritvdisplay/74f4e5050f189f82c

12573f00054efd0/$file/data%20sheet%20softmove%20lr.pdf). Such means are easily implemented by someone skilled in the art.

Although the robot(s) 22 is shown be mounted on the tool structure 10 of FIG. 1 , it can be appreciated that the robot(s) 22 can be mounted on any type of structure that can be moved and brought into the tire-changing environment. Thus, this disclosure is not limited to mounting the robot(s) 22 on the tool structure 10.

Some tools, such as electronic wrenches, can be controlled and monitored precisely. In one embodiment, such a precisely controlled and monitored tool, e.g. an electronic wrench 34, is used to set torque limits during fastening operations, e.g., mounting a nut or bolt. The limits can be configurable based on the design specifications of the current wheel and vehicle being serviced by the robotic tool structure 10. The actual torque values applied by the wrench 34 can also be logged and statistics collected (e.g., average torque, standard deviation of the torque, etc.) for further analysis and quality control. Damaged components, e.g., a broken bolt, can also be detected by monitoring changes in the torque values during the fastening and unfastening operations. This could be done using several means known by someone skilled in the art of signal processing. For example, a sudden drop in the running average of the fastening torque could indicate a broken bolt. Furthermore, the tool structure 10 can be configured to display warnings to an operator, such as when a certain torque value is exceeded, a certain number of broken fasteners is detected, etc.

[0047] With reference to FIG. 2, the robot 22 preferably includes a camera 35 with appropriate software, defining a vision guidance system. Using the camera 35, the vision guidance system is trained to find the bolts 30 on the vehicle hub 31 and bolt holes 36 in the rim 33 of the wheel assembly 27 (FIG. 15) for alignment. Furthermore, there is preferably some compliance between the robot 22 and the wrench 34. This will allow the wrench 34 to adjust slightly when there are small errors in the vision guidance system. The training and integration of the vision system with the robot system 22 is well known to someone skilled in the art.

[0048] In addition to using the vision system to guide the robot(s) 22 to attach and detach fasteners, the vision system can also be used for quality control. The robot(s) 22 can be programmed to inspect the ring of fasteners and inspect the number and position of the fasteners. In the case of removing a tire, this type of inspection can be used to confirm that all fasteners were properly removed. In the case of mounting a tire, this inspection can verify that all (or enough) fasteners are in the proper location. As stated above, the training and integration of such a vision system with the robot system 22 is well known to someone skilled in the art. [0049] With reference to FIG. 16, the tool structure 10 or 10"' is preferably mounted on a vehicle such as a standard wheel loader 38 for transporting and orienting the tool structure 10 with respect to a wheel assembly 27 to be serviced. The wheel loader 38 can be of the type such as the 988H wheel loader manufactured by Caterpillar. In particular, once the bucket of the wheel loader is removed, the mounting structure 20 of the tool structure 10 is mounted to an end 40 of the wheel loader 38 by bolts, pins or the like. After all the fasteners, e.g., bolts 30 have been removed as described above, the old wheel assembly 27 can be removed from the vehicle by another wheel loader having a conventional wheel/tire handler attachment that is configured to grasp and handle large wheels/tires. This wheel loader with tire handler attachment is also used to mount a new wheel assembly 27 on the hub 31 . Thereafter, the tool structure 10 can be moved into place, with the robot 22 attaching the fasteners, e.g., screwing in the bolts 30 to fasten the replacement wheel assembly 27 to the vehicle's hub 31 .

[0050] Although the tool structure 10 works well for its intended purpose, a disadvantage of the tool structure 10 is that two vehicles are needed to change a wheel assembly 27, one for moving the tool structure 10 and one to remove and remount the wheel assembly 27.

[0051] With reference to FIG. 4, a tool structure 10' is shown in accordance with another embodiment of the invention. The tool structure 10' increases the flexibility and speed of a robotic tire handling system by providing an active tire handling tool that can both house the robot 22 and handle the wheel assembly 27.

[0052] The tool structure 10' is active during the tire changing operation instead of being fixed. As shown in FIGs. 4-6, the tool structure 10' includes rigid frame structure, generally indicated as 12', including a generally square base 14 in the form of a plate and a rigid extension 16' extending from each corner of a common side 17 of the base 14. One or more rigid extensions 16' may be used for engaging the wheel assembly 27. As will all embodiments having rigid extensions, actuation of a rigid extension 16' so as to move in at least one direction may be accomplished with a cylinder 15 (FIGs. 15, 16), with the cylinder 15 being controlled by an input device 13 (FIG. 15) or by a vision guidance system using camera 35 (FIG. 16). Each rigid extension 16' includes a plurality of rollers 18' mounted in a row on a common axle 19 that is parallel to the axis A of the tire 32 or wheel assembly 27. The common axle 19 is coupled to the associated rigid extension 16' via linkage structure 41 so that the axle 19 and thus the rollers 18' can pivot with respect to the associated rigid extension 16'. The rollers 18' are constructed and arranged to grip the treads of the tire 32 on the wheel assembly 27 to be changed (FIG. 7). A total width of each row of rollers 18' is approximately equal to a width of the tire 32. In addition a roller 18" extends through an associated opening 42 in the plate 14. In the embodiment, four equally spaced rollers 18" are provided and arranged on axes generally perpendicular to axes of rollers 18' so as to engage the outside face 44 of the tire 32. It is noted that in FIG. 7, only the tire 32 of the wheel assembly 27 is shown.

Similar to the embodiment of FIG. 1 , the frame structure 12' may also include a mounting structure, generally indicated at 20', for mounting the robot 22 thereto. The mounting structure 20' includes a plurality of support members 24 joined to the base plate 14 and with some members 24 joined to each other. As best shown in FIGs. 4 and 5, the mounting structure 20' includes a plate 46 to which the robot 22 is mounted. Similar to the first embodiment, the mounting structure 20' is constructed and arranged to be mounted to a vehicle such as a wheel loader 38 (FIG. 16). The base plate 14 includes a central opening 26 so that the wrench 34 (not shown in FIGs. 4-6), coupled to end 28 of the robot 22, can engage the fasteners such as bolts 30 for removal or installation of a wheel assembly 27 with respect to the vehicle's hub 31 . [0054] At the start of the wheel changing operation, the tool structure 10', mounted to the wheel loader 38, is placed such that the four rows of rollers 1 8' surround the tire 32 that is being changed (see FIG. 7). The position of the four rows of rollers 1 8' is controlled such that they can engage and hold the tire firmly. The four rows of rollers 1 8' are constructed and arranged such that they permit the engaged large tire 32 and thus the wheel assembly 27 to rotate either clockwise or counter clockwise. This additional motion assists the tool structure 1 0' when a new wheel assembly 27 is being mounted to a vehicle.

[0055] The four rows of rollers 1 8' provide one degree of freedom for the tool structure

1 0', rotation around one axis (e.g., Rx). This configuration supplements the two degrees of freedom provided by the standard degrees of freedom of the wheel loader 38: up and down of the tool structure 1 0' (e.g., the X direction) and tilting of the tool structure 1 0' (e.g., pitch Ry). The tool structure 1 0' of the embodiment adds additional degrees of freedom by using conventional hydraulics 61 at the connection between the wheel loader 38 and the tool structure 1 0'. These hydraulics will allow the operator to move the tool structure 1 0' in Y, Z, and Ry, thus providing a full six degrees of freedom.

[0056] The six degrees of freedom provided by the tool structure 1 0' allows for great flexibility when trying to align the tool structure 1 0' with the wheel assembly 27. It allows the wheel loader 38 (FIG. 1 6) to be securely parked but still give enough freedom of movement to enable the tool structure to grip the tire 33 of the wheel to be changed, even when the tire's position and orientation are not strictly controlled or well-known at the start of the operation.

[0057] The tool structure 1 0' of the embodiment provides a mechanism for removing and replacing the wheels without the need of the second tire handling vehicle that is used with the tool structure 1 0 of the embodiment of FIG. 1 . [0058] With reference to FIGs. 8 and 9, in another embodiment, a mechanism similar to a Stewart platform is used to position a frame structure 12". The frame structure 12" has a base 14 and rigid extensions 16" extending from the base 14 for engaging the tire 32 of the wheel assembly 27. The robot 22 is mounted to the mounting structure, generally indicated at 20" of the frame structure 12". In accordance with the embodiment, the Stewart platform-type structure, generally indicated at 48, is coupled to the frame structure 12". The platform structure 48 includes a base platform 50 generally in the shape of an "L", which is constructed and arranged to connect to the existing linkages of the wheel loader 38 (FIG. 16). The wheel loader 38 will be able to lift this platform 50 vertically and pivot it as it would a bucket. The frame structure 12" is attached to the base platform 50 via six linear actuators, preferably in the form of piston-type cylinders 52 arranged generally in pairs.

[0059] Three rigid extensions 16" surround the large tire 33 and perform a scissor type motion. Each rigid extension 16" is actuated by two linear actuators, preferably piston-type cylinders. In particular and with reference to FIG. 9, each rigid extension 16" includes a first member 53 and a second member 54, each having an end pivotally coupled to a support 56 by connection 58. A first cylinder 60 has a first end 62 fixed to the first member 53 and a second end 64 fixed to the second member 54. Extension or retraction of the cylinder 60 moves the second member 54 away or towards the first member 53, respectively. A second cylinder 60 (not seen in FIG. 9) is connected in a similar way to the members 53 and 54 so that that extension or retraction of the second cylinder moves the first member 53 away or towards the second member 54, respectively, thereby defining the scissor type motion. Actuation of the cylinders 60 can be achieved by an input device 13 such as a joystick (FIG. 8) or by a vision guidance system using camera 35 (FIG. 16). Each rigid extension 16" includes an engagement structure preferably in the form of extended length gears 66 to grip the tire 32. The gears 66 can be controlled such that they will cause the tire 32 and thus the wheel assembly 27 to rotate either clockwise or counter clockwise. This additional motion assists the tool structure 10" when a new wheel assembly 27 is being mounted to the vehicle. It is noted that in FIGs. 7-9, only the tire 32 of the wheel assembly 27 is shown. However, it can be appreciated that the tire 32 is mounted on the rim 33 and the wheel assembly 27 is mounted to the hub 31 .

[0060] The three rigid extensions 16" provide one degree of freedom for the tool structure 10", rotation around one axis (e.g., Rx). This configuration supplements the two degrees of freedom provided by the wheel loader: up and down of the tool structure 10" (e.g., the X direction) and tilting of the tool structure 10" (e.g., Ry). The tool structure 10" adds six additional degrees of freedom through the coordinated movement of the six cylinders 52 coupled between the platform structure 48 and the frame structure 12". The cylinders of the platform structure 48 and wheel loader 38 and the rigid extensions 16" allow the operator to move the tool structure 10" in X, Y, Z, Rx, Ry and Rz, thus providing nine degrees of freedom.

[0061] The standard degrees of freedom of the wheel loader 38 as well as the gears 66 used to orient the large tire 32 will be used to move the tire 32 and thus wheel assembly 27 close to the final position and orientation with respect to the hub 31 . The six degrees of freedom provided by the cylinders 52 will be used to place the wheel assembly 27 in its final position and orientation.

[0062] With reference to FIGs. 10 and 1 1 , yet another embodiment of a tool structure is shown generally indicated at 10"'. The tool structure 10"' includes a rigid frame structure generally indicated at 12"' defined by a plurality of supports 68 defining substantially open sides 69 and an open front portion 71 for access to the fasteners 30 securing the wheel assembly 27 to the hub 31 . The frame structure 12"' is connected to a rigid platform structure, generally indicated at 70, via six linear actuators 72, preferably in the form of piston-type cylinders. These actuators 72 have connections 74 or bearings on both ends, such that in combination with the axial rotation of the cylindrical actuators 72 rotation around all three axes (e.g., Rx, Ry, and Rz) can be achieved. The side views of FIGs.

10 and 1 1 show only three of the actuators 72 because the tool structure 10"' is symmetric to the figure plane. All actuators 72 are seen in the bottom view of FIG. 14.

[0063] When installing a wheel assembly 27, the wheel assembly 27 is carried by the frame structure 12"' at the open front portion 71 thereof and is securely attached to the frame structure 12"' such that it cannot fall off when the frame structure 12"' is moving due to actuation of the cylinders 72. For example, FIG. 1 1 shows the cylinders 72 actuated to move the frame structure 12"' with respect to the platform structure 70, which is in a fixed position with respect to a vehicle while servicing the wheel assembly 27. In order to move the frame structure 12"' to a dedicated direction (X, Y, Z) or to rotate it about a dedicated orientation (roll, pitch, yaw), all six cylinders 72 must move at the same time at a certain relative speed to each other, depending on the position and orientation of the frame structure 12"'. There is a distinct relation between the cylinder positions p = (p1 , p2, p3, p4, p5, p6) and the frame position q = (X, Y, Z, Rx, Ry, and Rz), which needs to be calculated with a kinematic transform. The same is true for the speed of the cylinders dp/dt and the Cartesian speed dq/dt. This kinematic transform depends on the position of the swiveling connections 74 of all cylinders 72 and the position of the desired turning axes of roll, pitch, and yaw-motion. Preferably these three axes intersect at a point 76 which is the center of the wheel assembly 27 (FIG. 10).

[0064] The range of motion of the frame structure 12"' is limited by the range of the linear actuators 72 and the position of the swiveling connections 74. Usually, the range of motion is only a few feet translation and a few degrees rotation, which however is sufficient for wheel assembly and disassembly.

[0065] The basic control method for the tool structure 10"' is as follows: a mouse or joystick device 75 or similar means of operator input creates Cartesian motion commands for the frame structure 12"' (q and/or dq/dt). A controller 77 (preferably a PLC or an industrial PC) having a microprocessor 79 is operatively associated with the actuators 72. The microprocessor 79 performs the kinematic transform calculation and creates set motion commands for the linear actuators 72. Position and speed of each actuator 72 is preferably controlled by individual servo loops provided of the controller 77. The microprocessor 79 preferably also calculates the actual Cartesian motion from the actual actuator motion with the inverse kinematic transform. Instead of providing the joystick 75 on the tool structure 10"' as in FIG. 10, the control device for the operator can be a wireless panel/joystick allowing the operator to move around and watch from different locations while moving the frame structure 12"'.

For installation of a wheel assembly 27, the Cartesian motion commands for the frame structure 12"' allow motion upward and forward from a retracted rest position (FIG. 10) with respect to the vehicle's hub 31 to an assembly position (FIG. 1 1 ), with the wheel assembly 27 on the hub 31 . Once the wheel assembly 27 is in the proper position on the hub 31 , a wrench can be used manually to secure the wheel assembly 27 to the hub 31 via the fasteners such as bolts 30 or nuts. Alternatively, the frame structure 12"' can carry the robot 22 having the wrench 34 as in FIG. 16 for automated assembly. For removal of the wheel assembly 27 from the hub 31 , the Cartesian motion commands allow receiving and supporting of the wheel assembly 27 at the front portion 71 of the frame structure 12"' before removing all bolts, nuts, or other fasteners. The frame structure 12"' supports or holds the wheel assembly 27 while the fasteners 30 are being removed to stably hold the wheel assembly 27. Preferably there is a weight scale built into the frame structure 12"', showing the operator how far he needs to move the frame structure 12"' in the positive X-direction to make the weight of the wheel assembly 27 completely rest on the frame structure 12"' and not on the hub 31 . [0067] As shown in FIG. 13, the platform structure 70 may be carried by ground- engaging rollers 78 allowing the tool structure 10"' to be moved around more easily. The rollers or casters 78 are preferably retractable or can be blocked to provide a stable, non-moving base. The rollers 78 allow the platform structure 70 to move in the Z-direction, allowing compliance when the wheel assembly 27 is pushing against the hub 31 during assembly. This indicates that the wheel assembly 27 has reached its assembly position in Z-direction. The rollers or casters 78 can be power driven, allowing the operator to move the entire tool structure 10"'. For example, an engine 81 operating hydraulic pumps 83 can drive the rollers 78. The rollers 78 can be driven mecanum-type wheels, allowing the tool structure 10"' to move in any ground-engaging direction.

[0068] With reference to FIG. 14, the tool structure 10"' can include pairs of rollers 78, allowing movement of the tool structure 10"' either sideways in Y-direction via roller pairs 80 or in Z-direction via roller pairs 82. The pairs 80, 82 of rollers 78 can be retractable (e.g., using short hydraulic cylinders) such that the tool structure 10"' can rest either on the Y-direction roller pairs 80 or on the z- direction roller pairs 82. In addition, the tool structure 10"' can be stabilized and prevented from shifting on the ground by extending both types of roller pairs 80, 82 to the ground at the same time. The rollers 78 can be passive or driven (for example by hydraulic motors with gearbox). These pairs 80, 82 of rollers 78 allow the tool structure 10"' to be better positioned in front of the hub 31 .

[0069] With reference to FIG. 15, the platform structure 70 can be constructed and arranged to be attached to a vehicle 38 (e.g. wheel loader, forklift, etc.) to move it around, to place it in front of the hub 31 , and to prevent it from toppling over when the frame structure 12"' carrying the wheel assembly 27 is at extended positions. Alternatively, the tool structure 10"' can include a counterweight 83 to prevent it from toppling over when the frame structure 12"' carrying the wheel assembly 27 is at extended positions.

[0070] As shown in FIG. 12, the tool structure 10"' provides access for the operator to the inside of the frame structure 12"', allowing him to closely observe the fine- positioning of the rim of the wheel assembly 27 with respect to the hub 31 . Preferably, a height adjustable pedestal 84 mounted inside the frame structure 12"', allowing the operator to easily access all bolts or nuts around the rim of the wheel assembly 27. The pedestal 84 can tilt about the Z-axis to keep it leveled when the roll angle of the frame structure is less than or greater than 0 degrees. Preferably, there are means to rotate the wheel assembly 27 while sitting on the frame structure 12"' in order to align the position of the wheel's air-nozzle with the dedicated position at the hub 31 .

[0071] FIG. 15 shows the frame structure 12"' including rigid extensions 16"' (one seen in FIG. 15) that are constructed and arranged to grip the inside of the rim 33 of the wheel assembly 27 to hold it stably. . A hook 69 ensures that the wheel assembly 27 will not fall off the frame structure 12"' when the rigid extension 16"' is engaged with the wheel assembly 27. Alternatively, as shown in FIG. 16, the rigid extension 16 can be configured to can engage the tread portion of the tire 32. Although not shown in FIG. 16, certain rigid extensions 16 can include the plate 21 (FIG. 1 ) to ensure that the wheel assembly 27 will not fall off the frame structure 12"' when the rigid extension 16 is engaged with the wheel assembly 27. FIG. 16 also shows that the robot 22 can be mounted in the frame structure 12"'. [0072] With reference to FIG. 17, fence structure 71 is attached to the frame structure

12"' to cover certain openings (e.g., side openings) in the frame structure to provide additional safety between personnel located near the tool structure during its operation. The fence structure 71 can also include a controlled access point, such as a door (not shown). This door can be interlocked with the robot controller such that opening the door will cause the robot 22 and the tool 34 to stop running. Such a safety fence structure 71 can be installed by someone skilled in the art.

[0073] As seen in FIG. 10, the tool structure 10"' can include one or cameras 86 and/or sensors that provide feedback to the operator, allowing him to better observe the fine-positioning of the bolt holes 36 rim 37 (FIG. 4) of the wheel assembly 27 with the bolts 30 on the hub 31 (see FIG 2) and then observe the final movement of the wheel assembly 27 to engage with the hub 31 (FIG. 12). The cameras 86 and/or sensors can provide input to automatic calculation of the required motion of the frame structure 12"'. This would be an alternative to a manual input device for the operator and would allow fully automatic positioning of the frame structure 12"' with respect to the hub 31 . A graphical user interface or Human Machine Interface (HMI) 88 is provided for the operator and includes a display 90 (FIG. 18), showing numeric and graphical references of the frame structure 12"' status, such as actual position, errors, 3-D view of a real-time machine simulation, live- images from the cameras 86 or sensors.

[0074] For improved control, dedicated positions of the frame structure 12"' can be defined, e.g., a "transport" position, an "elevated working" position, a "maintenance" position, and a "fully retracted" position, which have a set of corresponding actuator positions p = (p1 , p2, p3, p4, p5, p6). These positions are preprogrammed in the microprocessor 79 and can be reached with simple operator commands such as a button-press rather than joystick inputs. The signals from sensors, cameras, or other feedback devices, provide set motion commands to automatically place the wheel assembly 27. The HMI 88 allows the graphical adjustment of the axes of the yaw-pitch-roll motions. Preferably, the intersection point of all axes can be represented by a single visual point on a HMI 88. After adjusting this point, the kinematic transform equations are automatically updated. If there are cameras or sensors used to automatically calculate required motion or target positions of the frame at the hub, the results of this calculation are displayed to the operator and can be adjusted and confirmed by the operator before the motion of the frame structure 12"' is initiated.

With reference to FIG. 18, the HMI 88, with display 90, allows the operator to control how the robot 22 installs and/or removes the fasteners, e.g. nuts or bolts with respect to a hub 31 . The HMI 88 allows the user to select from preexisting sequences or patterns, for example clockwise 94, counterclockwise 96, or other patterns 98. FIG. 18 shows a clockwise pattern with the robot 22 fastening and/or unfastening the fasteners in the clock-wise sequence of numbers 1 -9.... An option is also provided that will allow the operator to create a custom pattern 98 as shown in FIG. 19, wherein the order of fastening and/or unfastening the fasteners is indicated by numbers 1 , 2 and 3. Various other features could be added by the HMI 88, such as setting the desired torques limits, online viewing of torque values, etc. These HMI features can be created by someone skilled in the art. The HMI 88 can have other views, such as FIG. 20 which displays the robot's current position 100 and the snapshot or live image 102 of what one or more of the cameras can see. The operator could choose to view images from a camera 35 mounted on the robot(s) 22 or another camera 86 mounted to the frame structure 12. Another HMI view is shown in FIG. 21 which displays which fasteners are being operated on by the associated robot 22. For example, FIG. 21 shows a HMI screen where green circles 103 indicate fasteners that are successfully attached or removed and a yellow circle 105 indicates a fastener that is currently being operated on. Other states can be represented using additional colors, shapes, text, etc., such as using red to indicate a broken or missing fastener. FIG. 22 and FIG. 23 show status information 104, 106, about the tool structure 10, such as which devices are active, OK, in a fault state, etc, or status information about the robot 22.

[0076] Thus, the tool structure 10"' provides the following advantages: it can position the wheel 32 in all three directions and all three orientations (rotations) to provide six 6 degrees of freedom; it is driven by six linear actuators 72 (cylinders) that can be all of the same type; and it uses a kinematic transform calculation in order to translate linear motion commands along the three directions and three orientations into motion commands of the six linear actuators.

[0077] With reference to FIG. 24, one embodiment includes a fastener storage unit, generally indicated at 108. The unit 108 has a body 1 10 includes a plurality of threaded holes 1 12 to hold bolts that have been removed, and includes studs 1 14 to hold nuts that have been removed. Other fasteners could be held in a similar way. This fastener storage unit 108 can be mounted in the frame structure 12 such that the robot 22 will place fasteners in the unit 108 when removing a tire, and retrieve fasteners from the unit 108 when mounting a tire.

[0078] If a robot 22 is used that his mounted on a structure other than a tool structure as disclosed herein, once the robot removes the fasteners from the hub, a conventional wheel handler can be used to remove the wheel assembly from the hub and to place a new wheel assembly on the hub.

[0079] The foregoing preferred embodiments have been shown and described for the purposes of illustrating the structural and functional principles of the present invention, as well as illustrating the methods of employing the preferred embodiments and are subject to change without departing from such principles. Therefore, this invention includes all modifications encompassed within the spirit of the following claims.

Claims

What is claimed is:

1 . A tool structure for servicing a wheel assembly securable to a hub of a vehicle, the tool structure comprising:

rigid frame structure constructed and arranged to receive the wheel assembly in a supported manner,

a rigid platform structure constructed and arranged to be in a fixed position in relation to the vehicle while servicing the wheel assembly, and

linear actuators coupling the frame structure to the platform structure so that the frame structure can be oriented and positioned in a plurality of degrees of freedom with respect to the platform structure to position the wheel assembly with respect to the hub of the vehicle.

2. The tool structure of claim 1 , wherein there are six linear actuators, providing six degrees of freedom in motion of the frame structure.

3. The tool structure of claim 2, wherein each linear actuator is a piston type cylinder.

4. The tool structure of claim 3, wherein ends of the cylinder are connected between the platform structure and the frame structure by a connection that provides one or more rotational degrees of freedom.

5. The tool structure of claim 1 , wherein the platform structure is constructed and arranged to be connected to a vehicle for moving the tool structure.

6. The tool structure of claim 1 , further comprising ground-engaging rollers on the platform structure for movement of the tool structure.

7. The tool structure of claim 6, wherein the rollers are power driven and constructed and arranged to permit the tool structure to move in any ground-engaging direction.

8. The tool structure of claim 6, wherein the rollers include first and second pairs of rollers, the first pairs of rollers being constructed and arranged to permit movement of the tool structure in a first direction, and the second pairs of rollers being constructed and arranged to permit movement of the tool structure in a direction different from the first direction.

9. The tool structure of claim 1 , further comprising a pedestal mounted it the frame structure constructed and arranged to support an operator of the tool structure.

10. The tool structure of claim 1 , further comprising a controller associated with the linear actuators and constructed and arranged to control movement of the linear actuators.

1 1 . The tool structure of claim 10, further comprising a joystick or other input device to provide an input from an operator.

12. The tool structure of claim 10, wherein the controller is constructed and arranged to move the linear actuators simultaneously at certain relative speeds.

13. The tool structure of claim 1 , in combination with the wheel assembly, the wheel assembly including a rim including a plurality of fastening features, the hub including a plurality of mating fastening features, the frame structure being constructed and arranged to be moved by the actuators to orient the rim fastening features with the mating hub fastening features.

14. The tool structure of claim 1 , further including at least one robot mounted on the frame structure, the robot having a tool constructed and arranged to install or remove a fastener.

15. The tool structure of claim 1 , further comprising at least one camera and a graphical user interface for displaying live images from the at least one camera.

16. The tool structure of claim 14, further comprising at least one camera and a graphical user interface for displaying live images from the at least one camera.

17. The tool structure of claim 16, wherein the graphical user interface is constructed and arranged to permit an operator to select a sequence that the robot will remove or install a plurality of fasteners.

18. The tool structure of claim 1 , further comprising a fence structure coupled with the frame structure to cover certain openings in the frame structure.

19. The tool structure of claim 1 , further comprising rigid extensions coupled to the frame structure constructed and arranged to engage a portion of the wheel assembly to stably hold the wheel assembly during servicing of the wheel assembly.

20. The tool structure of claim 19, whereon one or more of the rigid extensions are constructed and arranged to be actuated to move in at least one direction.

21 . A method of mounting a wheel assembly on a hub of a vehicle, the method comprising steps of:

providing a rigid frame structure coupled to a platform structure by a plurality of linear actuators so that the frame structure can move relative to the platform structure in a plurality of degrees of freedom,

loading a wheel assembly in the frame structure, moving the frame structure to orient the wheel assembly with respect to the hub of the vehicle,

further moving the frame structure so that the wheel assembly is engaged with the hub, and

securing the wheel assembly to the hub.

22. The method of claim 21 , wherein the wheel assembly includes a rim with a plurality of fastening features therein and the hub includes a plurality of mating fastening features, wherein the step of moving the frame structure to orient the wheel assembly includes orienting the rim fastening features with the mating hub fastening features.

23. The method of claim 21 , wherein six linear actuators couple the frame structure to the platform structure such that the step of moving the frame structure to orient the wheel assembly orients the frame structure in any of six degrees of freedom.

24. The method of claim 21 , wherein the platform structure includes power driven, ground engaging rollers, the method further includes moving the tool structure together with the wheel assembly via the power driven rollers.