CN112423996A

CN112423996A - Robot apparatus for maintaining wheels of vehicle and method thereof

Info

Publication number: CN112423996A
Application number: CN201980029760.6A
Authority: CN
Inventors: 文洪财
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-05-03
Filing date: 2019-05-03
Publication date: 2021-02-26
Also published as: WO2019210390A1

Abstract

A robotic tool having a chassis and a wheel maintenance subsystem supported on the chassis, the wheel maintenance subsystem having a subsystem interface element capable of interacting with an interface element of a wheel, the subsystem interface element of the wheel maintenance subsystem being capable of interacting with a corresponding interface element of the wheel such that the wheel maintenance subsystem is capable of performing operations for maintaining the wheel, and a control system for controlling the operation of the chassis and the wheel maintenance subsystem for performing the wheel maintenance operations. The wheel maintenance subsystem is one or more of a chassis subsystem, a tool support subsystem, a fastener installation/removal subsystem, a fastener storage subsystem, a lifting subsystem, and a wheel gripping subsystem.

Description

Robot apparatus for maintaining wheels of vehicle and method thereof

Cross reference to related patent

The present patent application for filing into the united states is a continuation of a portion of us patent application 16104792 filed on 8/17/2018 entitled "apparatus and method for installing and removing circular array threaded fasteners".

According to 35 u.s.c. § 119(e), the present application claims priority from us provisional application No. 62666481 filed on 3/5/2018 and us provisional application No. 62670596 filed on 11/5/2018.

The disclosure of the above-mentioned provisional application is incorporated herein by reference in its entirety and is made a part of this application for all purposes.

Technical Field

The present invention relates to a robotic tool and method for automatically maintaining wheels of a vehicle.

Background

During a complete operation of maintaining a wheel, whether a new wheel is being maintained, or a wheel that has been mounted on or removed from the vehicle is being maintained, there may be a very large number of specific steps that need to be performed. For example, such maintenance may involve any or all of the following: the method includes the steps of finding and identifying a target wheel to be maintained, jacking up a portion of the vehicle on which the target wheel is located, loosening and removing nuts or other types of fasteners from the vehicle hub bolts to secure the wheel, and properly positioning the removed wheel fasteners for mounting the original wheel or another wheel, gripping and removing the wheel, checking for wheel damage, remaining useful life of the tread pattern, dynamic balancing of the wheel, testing and adjusting tire pressure, and the like. There are different types, brands and models of vehicles and accordingly, there are different widths, diameters and configurations of different vehicles and wheels. Currently, most wheel maintenance operations are performed manually by a service technician at various service stations in a vehicle service facility located alongside a roadway or elsewhere. This manpower intensive wheel maintenance is expensive today and is often inconvenient.

Co-pending U.S. patent application 16104792 describes an automatic installation/removal device for threaded fasteners suitable for installing and removing a wheel from a vehicle. However, the installation and removal of threaded fasteners such as wheel nuts is only a part of the operation of automatically replacing the wheel. It would be of great value if the remaining operations of wheel maintenance could be performed automatically, in addition to the initial control, to eliminate manual intervention and labor, either partially or completely.

Disclosure of Invention

According to one aspect of the invention, a robotic tool has a chassis, and at least one wheel maintenance subsystem supported on the chassis, the wheel maintenance subsystem having an axis of operation, and a subsystem interface component engageable with an interface component of a wheel, the engagement of the subsystem interface component with the wheel interface component enabling the wheel maintenance subsystem to perform a wheel maintenance operation, and a control system capable of controlling the operation of the wheel maintenance subsystem enabling the wheel maintenance subsystem to perform the wheel maintenance operation.

The chassis has rollers for supporting the chassis on a support surface, and first and second roller drive motors are capable of driving the respective first and second rollers to rotate about a generally horizontal axis, thereby changing the position of the operational axis. The roller drive motors are preferably independent of each other and enable the first and second rollers to have different rotational speeds and different rotational directions. The chassis preferably also has third and fourth drive motors for driving the first and second rollers to change angles, and thus change the driving directions of the first and second rollers, respectively, independently of each other about a vertical axis.

The present robotic tool may further comprise a support plate located above and connected to the chassis by a linkage for supporting the wheel maintenance subsystem, and a drive motor for adjusting the linkage to change the spacing of the support plate from the chassis, thereby changing the position of the axis of operation of the robotic tool. The robotic tool may further comprise a drive motor for changing the angle of the support plate relative to the chassis, thereby changing the orientation of the operating axis.

One of the wheel maintenance subsystems may be a fastener installation/removal subsystem for installing or removing a wheel to or from the hub of a vehicle, such as the fastener handler described in co-pending U.S. patent application, having sleeves capable of holding removed wheel fasteners and distributed in a circular array with an adjustable pitch circle radius.

One of the wheel maintenance subsystems may be a fastener storage subsystem that is used to store wheel fasteners removed from the wheel on the robot when the wheel is removed, and when the wheel is subsequently installed, the subsystem may remove the stored wheel fasteners that are needed from the robot tool so that they can be installed onto the bolts of the hub. The storage subsystem may have several storage stations, each having storage receptacles distributed in a circular array for storing fasteners. The storage receptacle may have magnetic elements that are used to draw the wheel fasteners from the sleeves and retain the drawn wheel fasteners on the storage receptacle. The sleeves may also have corresponding magnetic elements thereon so that when it is desired to transfer a wheel fastener from a storage receptacle to a sleeve, the magnetic elements of the sleeve may draw the wheel fastener from the storage receptacle. At least one of the magnetic elements may be an electromagnet that may be energized or de-energized for magnetically attracting, transferring and releasing the wheel fastener.

One of the wheel maintenance subsystems may be a lifting subsystem for lifting a portion of the vehicle for any manner of access, removal, or installation of the wheel to be maintained. The subsystem is preferably formed by a plurality of lifts each independently liftable and lowerable mounted on the robotic tool and each having a base for contacting the ground and a vehicle support member capable of contacting a lifting point on the vehicle and capable of bearing at least a portion of the weight of the vehicle. Each of the lifts described above preferably has a motor capable of driving the vehicle support member thereon upwardly away from the base to lift a portion of the weight of the vehicle. Each lift is preferably mounted in a mounting bracket on the tool when in the standby state, and the mounted lift can be separated from its corresponding mounting bracket when the lift is fixed to the ground by the weight of the vehicle and the chassis of the robotic tool is clear of the lift.

The wheel maintenance subsystem may be a wheel gripping subsystem having at least three gripping jaws that may be deployed to grip the tread of the wheel to be maintained. The jaws lie on a circle centred on the operating axis and each jaw is preferably mounted to perform radial movement away from or towards the operating axis. Each grip preferably has a first set of sensors mounted thereon for detecting the proximity and distance of the tread of the wheel, and each grip preferably has a second set of sensors mounted thereon for detecting the proximity and distance of the sidewall of the wheel being gripped. In addition, a camera is preferably mounted on each of the gripping claws to allow inspection of at least one of the outer side wall of the tire, the tread of the tire and the outer side of the rim when the wheel is rotated about the operating axis. The wheel-gripping subsystem preferably also has a camera mounted on an articulated arm mounted to one of the jaws, which can be maneuvered into a position to view the inside surface of the wheel as it rotates about the operational axis. Each gripper preferably also has one or more rollers rotatable about a respective axis to allow rotation of the wheel being gripped. One or more of the gripping jaws may have a motor capable of driving rotation of one of the rollers to cause the roller to rotate about its axis, thereby causing the wheel being gripped to rotate in the opposite direction about the operating axis.

The wheel maintenance subsystem may be a tire pressure regulating subsystem for testing and regulating the pressure of the tire of the wheel. In its most preferred embodiment, the tire pressure regulating and measuring subsystem has an interface member mounted on a support frame, the support frame being rotatable about an operational axis; the tire pressure regulating and measuring subsystem is also provided with a tire pressure measuring unit which can be in butt joint with a wheel air nozzle needle valve and can measure the pressure of the tire; the tire pressure regulating and measuring subsystem is also provided with a tire pressure regulating unit which can be butted with a wheel air nozzle needle valve and can pump or release the air pressure of the tire, and the tire pressure regulating unit and the tire pressure measuring unit are arranged together; the tire pressure regulating and measuring subsystem preferably further comprises an air nozzle dust cap removal/installation unit capable of interfacing with the wheel air nozzle to remove the dust cap from the air nozzle and to place the dust cap onto the wheel air nozzle and secure it in place. The or each unit is mounted on a support in a mounting mechanism, the support being mounted on the carriage. Preferably, the mounting means comprises a rotation and translation motor capable of guiding the or each unit to the wheel valve and of manipulating the or each unit to interface with the wheel valve.

One of the wheel maintenance subsystems may be an automatic wheel dynamic balancing subsystem having a conical assembly and a drum assembly between which a rim of a gripped wheel can be automatically clamped so that the clamped wheel is free to rotate about its central axis when the gripping jaws release the wheel. The wheel dynamic balancing subsystem may have a vibration monitoring system for monitoring x-axis, y-axis and/or z-axis vibration parameters and correlating these parameters to the rotational position of the wheel.

The wheel dynamic balancing subsystem may have one or more secondary mechanisms mounted on one or more articulated arms. One of the auxiliary mechanisms may be a mechanism capable of automatically removing the old weight from the rim. One of the auxiliary means may be a means for automatically spraying and cleaning the site where the new counterweight blocks are to be placed. One of the auxiliary mechanisms may also be a mechanism capable of automatically guiding and fixing the new weights to predetermined seating positions on the rim. One of the auxiliary mechanisms may also be a mechanism that is capable of automatically removing and storing the rim centre cover. One of the auxiliary mechanisms may also be a mechanism that is capable of automatically removing and storing gravel and similar foreign matter on the tire tread.

Brief description of the drawings

For simplicity and clarity of illustration, elements illustrated in the figures have not been drawn to scale in general. For example, the dimensions of some of the elements are exaggerated relative to other elements for clarity. The advantages, features, and characteristics of the present invention, as well as the methods, operations, and functions of the related elements of structure, and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following description, the appended claims, and the accompanying drawings, all of which form a part of this specification, wherein like reference numerals designate corresponding parts in the various figures, and in which:

fig. 1 is a front side three-dimensional view of one embodiment of the wheel servicing robot tool of the present invention.

Fig. 2 is a rear side three-dimensional view of the robotic tool of fig. 1.

Fig. 3 is a side view of the robotic tool of fig. 1.

Fig. 4 is an exploded rear side three-dimensional view of the robotic tool of fig. 1.

Fig. 5 is a side front three-dimensional view of a chassis subsystem of the robotic tool of fig. 1, as one embodiment of the present invention.

FIG. 6 is a bottom three-dimensional view of the rear side looking down on the chassis subsystem shown in FIG. 5.

FIG. 7 is a side rear three-dimensional view of a support subsystem of the robotic tool of FIG. 1, as one embodiment of the present invention.

Fig. 8 is an exploded view of a support subsystem of the robotic tool of fig. 7.

Fig. 9 is a side view of the robotic implement support subsystem shown in fig. 7 in a first articulated state.

Fig. 10 is a side view of the robotic implement support subsystem shown in fig. 7 in a second articulated state.

Fig. 11 is a side view of the robotic implement support subsystem shown in fig. 7 in a third articulated state.

Fig. 12 is a side view of the robotic implement support subsystem shown in fig. 7 in a fourth articulated state.

Fig. 13 is a side front three-dimensional bottom view of a lifting subsystem of the robotic tool of fig. 1, as an embodiment of the present invention.

FIG. 14 is a side up three dimensional view of the lifting subsystem shown in FIG. 13.

FIG. 15 is a bottom view of the lifting subsystem shown in FIG. 13.

FIG. 16 is a partial three-dimensional view of the lifting subsystem shown in FIG. 13 at a stage when it is activated.

FIG. 17 is a partial three-dimensional view with the same position and orientation as FIG. 16, but with the lifting subsystem in the next stage of being activated.

FIG. 18 is a partial three-dimensional view with the same position and orientation as FIG. 17, but with the lifting subsystem in yet another stage of being activated.

FIG. 19 is a side front three-dimensional view of a wheel gripping subsystem as part of the robotic tool of FIG. 1 in one embodiment of the present invention.

FIG. 20 is a side rear three-dimensional view of the wheel-gripping subsystem shown in FIG. 19, with the wheel-gripping subsystem at a stage of being activated.

Fig. 21 is a side rear three-dimensional view of the wheel-gripping subsystem shown in fig. 20. With the wheel holding subsystem in the next stage of being enabled.

FIG. 22 is a side front three-dimensional view of the wheel showing the axial positioning of the wheel gripping subsystem of FIG. 19 relative to the wheel using a first set of sensors.

FIG. 23 is a side view of a wheel illustrating the radial positioning of the wheel gripping subsystem of FIG. 19 relative to the wheel using a second set of sensors.

FIG. 23A is a partial three-dimensional view of one embodiment of a gripping claw used in the wheel gripping subsystem shown in FIG. 19.

FIG. 24 is a three-dimensional side-rear looking view of a portion of the robotic tool of FIG. 1 illustrating a fastener storage subsystem, as an embodiment of the present invention.

FIG. 25 is a three-dimensional view of the fastener storage subsystem shown in FIG. 24 looking down from the side front.

FIG. 26 is a schematic diagram illustrating a fastener storage station that is part of the fastener storage subsystem shown in FIG. 24.

Fig. 27 is a three-dimensional view of the sleeve mechanism of a fastener unit used to temporarily hold the position of wheel fasteners in preparation for storage of the wheel fasteners.

FIG. 28 is a front view of a portion of the fastener storage subsystem of FIG. 24, showing the array of fastener storage receptacles and the array of fastener sleeves at a stage in the fastener storage process.

FIG. 29 is the array of fastener storage receptacles and the array of fastener sleeves of FIG. 28, at a next stage in the fastener storage process.

FIG. 30 is a side view of a portion of the fastener storage subsystem of FIG. 24, illustrating an initial stage in the process of transferring fasteners from the sleeve of the fastener system to a fastener storage receptacle in the fastener storage subsystem.

FIG. 31 is a side view corresponding to that of FIG. 30 showing a next stage in the fastener delivery process.

FIG. 32 is a side view corresponding to that of FIG. 30 showing yet another stage in the fastener delivery process.

Fig. 33 is a side rear three-dimensional view of the robotic tool of fig. 1, illustrating a tire pressure regulating subsystem, as an embodiment of the present invention.

FIG. 34 is a side rear three-dimensional view of the robotic tool of FIG. 1 illustrating a tire pressure regulating subsystem being adjusted for docking to a wheel air nozzle needle valve.

Fig. 35 is a partial view of the tire pressure regulating subsystem from the rear and above, wherein the tire pressure regulating subsystem associated components have been docked to the wheel air nozzle needle valve.

Fig. 36 is a side front three dimensional view of a portion of the robotic tool of fig. 1 illustrating a wheel dynamic balancing subsystem, as an embodiment of the present invention.

FIG. 37 is a side rear plan view of the components shown in FIG. 36.

Fig. 38 is a rear elevational view of the dynamic wheel balancing subsystem of fig. 36, showing the operating arm in a first position.

Fig. 39 is a side view corresponding to fig. 38.

Fig. 40 is a rear elevational view of the dynamic wheel balancing subsystem of fig. 36, showing the operating arm in a second position.

Fig. 41 is a side view corresponding to fig. 40.

Fig. 42 is a rear elevational view of the dynamic wheel balancing subsystem illustrated in fig. 36, showing the operating arm in a third position.

Figure 43 shows an enlarged partial view of the wheel being rotated using the gripping claws.

Fig. 44 is a three-dimensional view of a portion of the pressure plate assembly of the dynamic wheel balancing subsystem of fig. 36.

FIG. 45 is a three-dimensional exploded view of a portion of the cone head assembly of the dynamic wheel balancing subsystem of FIG. 36.

FIG. 46 is a three dimensional view of a rim center cover remover that is part of the dynamic balancing subsystem of the wheel of FIG. 36, illustrating a preparatory phase to an operating step, in accordance with an embodiment of the present invention.

FIG. 47 is a three-dimensional cross-sectional view corresponding to FIG. 46, showing a next stage in the rim center cover remover operating step.

Fig. 48 is a main flow diagram of the overall control system of the robotic tool in one embodiment of the present invention.

FIG. 49 is a flowchart illustrating operation of a chassis control module in the overall control system shown in FIG. 48, in accordance with an embodiment of the present invention.

FIG. 50 is a flowchart of the operation of the tool support subsystem control module in the overall control system, as shown in FIG. 48, in one embodiment of the present invention.

FIG. 51 is a flowchart of the operation of a vehicle lift subsystem control module in the overall control system, as shown in FIG. 48, in one embodiment of the present invention.

FIG. 52 is a flow chart of the operation of the wheel alignment and proximity control modules in the overall control system as shown in FIG. 48 in one embodiment of the present invention.

FIG. 53 is a flowchart illustrating the operation of the wheel-holding control module in the overall control system shown in FIG. 48, in accordance with an embodiment of the present invention.

FIG. 54 is a flowchart of the operation of a fastener storage control module in the overall control system, such as that shown in FIG. 48, in one embodiment of the invention.

FIG. 55 is a flow chart of the operation of the wheel inspection control module in the overall control system as shown in FIG. 48 in one embodiment of the present invention.

FIG. 56 is a flowchart illustrating the operation of the wheel dynamic balancing module in the overall control system shown in FIG. 48, in accordance with an embodiment of the present invention.

FIG. 57 is a continuation of the workflow diagram shown in FIG. 56.

FIG. 58 is a flowchart illustrating the operation of the tire pressure regulating module in the overall control system shown in FIG. 48 according to one embodiment of the present invention.

Detailed description of the invention including presently preferred embodiments

As shown in fig. 1, 2, 3, 4, a robotic tool 8 for maintaining wheels of a vehicle has several wheel maintenance subsystems:

a chassis subsystem 10;

a tool support subsystem 12;

fastener installation/removal subsystem 14;

a fastener storage subsystem 15;

a lifting subsystem 16;

a gripping subsystem 18;

a wheel surface inspection subsystem 20;

a tire pressure subsystem 22;

a wheel dynamic balancing subsystem 24.

Each wheel maintenance subsystem has one or more interface components that are automatically engageable with a corresponding wheel interface component under the control of the control system, which engagement enables automatic operation of the corresponding wheel maintenance subsystem to maintain the wheel. In one embodiment of the invention, when maintenance of the wheel is required, the exemplary steps described below will be performed in the order described below.

Fig. 48 is a main flow diagram of the overall control system of the robotic tool in one embodiment of the present invention. In accordance with the principles described in fig. 48, the built-in control system of the robotic tool receives instructions from a control center over a wireless network or other communication channel to identify work tasks to be performed. The control system then controls the robotic tool to perform all of the designated maintenance operations in accordance with the received instructions, without human intervention, unless the control system receives a report on a fault or other problem that requires investigation, which may result in the control system receiving further instructions from the control center, or being manually intervened to manually resolve the problem. The initial instructions sent by the control center to the robotic tool may instruct where to perform a task, such as providing position data (e.g., GPS coordinates) of the target vehicle, or data of a travel path required to reach the target vehicle, data related to the target vehicle (e.g., vehicle model, year, color, license plate number and shape, wheel maintenance history, vehicle profile, wheel size, torque criteria, etc.), and providing images related to the target vehicle, such as images of the body, underbody lift point, etc. Once the target vehicle is within the autonomous movement range of the robot tool, the robot tool moves to the vicinity of the target vehicle according to a movement path, wherein the source of the movement path can be movement path data sent by a control center or a movement path obtained by analyzing and calculating an image obtained by a camera of the robot tool in the movement process by using the machine vision of the robot tool. When the robot tool approaches the target vehicle, it will take a picture of the appearance characteristics of the target vehicle and check it against the corresponding data contained in the command to confirm that the approaching vehicle is indeed the target vehicle. According to the instructions of the control center, the control system of the robot can make a detailed operation list and sequence. For example, in what order the lifting points are lifted. The camera of the robotic tool then works with the control system to identify the parking direction of the vehicle and the position of the wheel to be removed, and the robotic tool is then moved to the appropriate side of the vehicle and properly positioned relative to the vehicle. As shown in fig. 48, the control system sends control signals to each subsystem during the activation and operation of the relevant subsystem. Typically, these control signals are output to devices such as switches, motors and other actuators. As each subsystem operates, each subsystem also generates and sends an output signal to the control system to report the operation of the subsystem. Typically, these include output signals from cameras and sensors that can be received and analyzed by the control system. The control system includes a machine vision subsystem that analyzes the components of the target wheel being maintained and the image of the maintenance subsystem performing the maintenance operation, such that the control system can independently utilize the analysis of the machine vision system or further combine with data from other sources to effect real-time control and adjustment of the respective subsystems. The cameras and their location are not shown in the drawings, but it will be understood that they are mounted in place.

As shown in fig. 5, 6, the robotic tool 8 is primarily moved by movement of its wheeled chassis 10 over a support surface such as the ground. The drive motors built into the chassis 10 can be driven in unison to drive the chassis in linear, curvilinear and rotational motion on the support surface. Four

rollers

27 and 28 mounted on the chassis above the support 30 are each located at the apex of the approximate diamond shape. The idler wheels or casters 27 attached to the carriage 30 and swingable are attached to the front and rear vertices of the diamond, and the drive wheels or drive rollers 28 attached to the carriage 30 are attached to the opposite side vertices of the diamond in parallel. The drive wheels are controlled to change the orientation of their respective horizontal axes of rotation so that the horizontal axes of rotation of the two drive wheels can form any angle, including parallel and non-parallel. Each drive wheel can be independently driven by the motor 32 to rotate independently at the same or different speed and direction of rotation, thereby driving the robotic tool 8 in any direction and any path within a range. The drive wheels 28 are also mounted independently along a vertical axis and can be rotated independently by respective rotation motors 34 so that each drive wheel can change its drive orientation, thereby allowing a greater degree of freedom in the independent movement of the two drive wheels. The design allows translational movement of the robotic tool in any direction parallel to the support surface, as well as rotation of the robotic tool about any vertical axis, and further allows movement of the robotic tool in any combination of the translational movement described above and rotation about any vertical axis. This design provides the robotic tool with a highly flexible and comprehensive translational and rotational movement capability, which is very valuable for operation in confined spaces. FIG. 49 is a flow chart illustrating the operation of the chassis drive and steering control module.

As shown in fig. 7 to 12, the tool support platform 40 is mounted on the wheeled chassis 10 by means of front 36 and rear 38 struts, the upper and lower ends of the front 36 and rear 38 struts being hingedly mounted to the support platform 40 and chassis bracket 30 respectively. The lower end of the rear pillar 38 is slidably mounted in a horizontal slot 42 in a vertical straight plate 44 integral with the chassis frame 30, the straight plate 44 being parallel to the chassis fore-aft axis A. The linear motor 46 may move the lower end of the rear strut 38 along the slot 42 between two dead centers of the slot 42. The outer end of the moving rod 48 of the linear motor 50 is hingedly mounted to the upper end of the rear strut 38 and the outer end of the stator of the linear motor 50 is hingedly mounted to the lower end 36 of the front strut. The linear motor 50 is capable of changing the spacing between the upper end of the rear pillars and the lower end of the front pillars. Coordinated action of the

motors

46, 50 can raise, lower, tilt forward or backward the support platform 40 and the subsystems supported thereon. As shown in fig. 9-12,

motors

46, 50 are capable of adjusting the height and tilt angle of support platform 40 in any given sequence and in appropriate increments to achieve any combination of height changes and tilt angle changes within the allowable range for support platform 40. The order of adjustment of the height and inclination angles is important in view of the compact arrangement of the wheel maintenance subsystems, the need for precise control of the movements of the robotic tool and its subsystems to prevent collisions and movement interference between the subsystem components. One particular combination of the tilt angle θ and the height H corresponds to one particular combination of the displacement L1 of the motor 46 and the displacement L2 of the motor 50. For a desired set of values of θ and H, the control system can calculate the corresponding values of L1 and L2 and adjust the displacement of each of the two motors either cooperatively at once or in some order based on the values of L1 and L2. The main functional requirements of the tool support subsystem are to adjust the height of the front end of the fastener subsystem, and simultaneously adjust the inclination angle of the front end of the fastener subsystem within a certain angle range at any height, and ensure that the front end of the fastener subsystem is located at a proper position in front of the chassis, and the wheel holding subsystem is not blocked by the chassis. The elevation and tilt functions of the tool support subsystem described above may also be accomplished by an alternative to the mechanisms described above, such as one or more vertically disposed linear motors having their bottoms mounted on the chassis frame and their moving bars hinged and slidably mounted on the underside of the support plate. The above-mentioned and any other linear or rotary motors used in robotic tools may be equipped to be able to measure their displacement or angular change for subsequent control needs. Alternatively, or additionally, height and tilt angle measuring mechanisms may be mounted on the tool support platform. FIG. 50 is a control flow diagram of the tool support control module.

Suspended from the rear sides of the chassis frame 30, as shown in fig. 13-18, is a lifting subsystem 16 having four lifts 52, each lift 52 being independently extendable to lift a portion of a target vehicle 54. The lift subsystem has two lift stations 56, each lift station 56 having a pair of lifts 52 mounted therein. Each lift station 56 is mounted on a slide member 57, and the slide members 57 are secured to slide rail members 58 mounted to the chassis base 30. The slide components are arranged so that each lift station 56 can be pushed out on the slide member 58 in a direction parallel to the operating axis and then back. To achieve this, a moving rod 61 of a linear motor 62 is connected to the slide member 57, and the moving rod 61 can move back and forth in the barrel 60 of the linear motor 62. The carriages of each lift station have housings 64, each of which can receive and hold in place prong tabs 66 on the lift 52 so that the lift is held in the lift station in the standby mode and can be separated from the housings 64 when a particular lift is deployed. The housing has upper and lower guide tabs 65 for guiding the prong blades 66 into the housing 64.

When it is desired to activate a particular lift 52 to lift a vehicle, the chassis is rotated so that the lift station 56 faces the vehicle 54. Subsequently, based on the control system's query for body lift point position data, the chassis will adjust positions such that some of the available lifts 53 are approximately laterally aligned with the expected position of the target lift points 68 of the target vehicle. The built-in camera generates an image of the underside of the vehicle and analyzes the image using a machine vision system to identify the exact location of the target lift point. In one embodiment of the lift subsystem 16, cameras are mounted on the four front, rear, left and right corners of the chassis frame 30, the lift stations 56 and each lift 52, and there is a laser point source at the center of the lift head 70 of each lift.

In cooperation, the linear motor of the selected lift station 56 will be activated to slide the lift station 56 out of the cage, moving the lift head 70 of the selected lift directly below the target vehicle lifting point (FIG. 16). The rotary motor 72 on the selected lift 52 is then activated to turn the screw actuator 74, causing the lift to be positioned to produce a scissor lift action, thereby raising the lift head to contact and lift a portion of the vehicle above it (fig. 17). After a portion of the vehicle is lifted, a portion of the weight of the vehicle is supported by the deployed lift, and the lift base is pressed against the ground or other support surface. The robotic tool 8 can then be disconnected from the deployed jacks 52 by simply driving the chassis 10 back away from the vehicle 54, sliding the prong blades 66 out of the housing 64 on the docking station (fig. 18). The chassis 10 can then be moved to a position near another lifting point on the same side or the other side of the vehicle where a second lift 52 can be deployed in the same manner. After a particular maintenance phase is completed, the reverse sequence of operations may be employed to remove the lift from the vehicle and re-home it to the robotic tool.

To lift the vehicle to remove the wheel, the robotic tool is moved to a position proximate to the lift point of the target wheel and rotated so that the back of the robotic tool faces the vehicle. One of the two lift stations 56 is then slid along the sliding suspension member 58 toward the vehicle 54. When the lift 52 reaches the proper position, the lift station 56 and the cameras on the lift 52 will scan the image under the vehicle. The machine vision system checks the scanned image against the stored image of the target lift point and adjusts the position of the selected lift as needed until a matching position is found. The wheeled chassis and the lift station 56 are moved in coordination so that the lift head of one of the lifts is vertically aligned with the center of the vehicle lift point. The vertical alignment is determined by the coincidence of the lift point with a laser point emitted upward from a laser source in the center of the lift. The lift motor is then activated to lift a portion of the vehicle above the lift to the height given by the service command and the scissor lift motion of the lift is detected to monitor the lift height. The camera may monitor the clearance between the tire tread and the ground or other support surface. Once the vehicle is lifted to the desired height so that the clearance between the vehicle and the ground is required, the motor of the lift is turned off. The lift station motor and chassis drive wheels are then activated to retract the lift station 56 and move the robotic tool away from the vehicle. Since the deployed lift supports the vehicle, the bottom of the lift is pressed firmly against the ground, so that the tabs 66 slide out of the lift station housing 64 when the robotic tool is moved rearward. A portion of any one or more of the remaining lifts may then be deployed at another lifting point of the vehicle to lift the vehicle, or the robotic tool may move to another location to lift another vehicle, in accordance with the control instructions. The robot tool is now ready for the next maintenance task. In another operational sequence, the machine vision system may directly calculate coordinates of a lift point of the target vehicle relative to the robotic tool and manipulate the robotic tool to move a lift head of the lift directly to a position of the target lift point. When the replacement or other maintenance of the wheels is complete, the lift may be removed by a sequence substantially opposite to the steps described above. FIG. 51 is a flow chart of the operation of a vehicle lift subsystem that may be used with the control system shown in FIG. 48, in accordance with an embodiment of the present invention.

Many wheel maintenance operations can be performed even if the wheel is still mounted on the vehicle. If the wheel, which is also mounted on the vehicle, cannot be subjected to some wheel maintenance operation, the robotic tool may use a fastener installation/removal subsystem (e.g., a fastener installation/removal device of the type disclosed in co-pending U.S. patent application 16104792) to remove the wheel from the vehicle hub in preparation for the maintenance operation. When the vehicle is lifted and a wheel is off the ground, the wheel may be free to rotate or may not be able to rotate due to being locked by the vehicle driveline or parking brake, which may be confirmed based on vehicle data received by the control system. In a derivative version of the vehicle lifting procedure, when it is desired to install or remove a wheel that is free to rotate when lifted, the lifting or lowering action of the lift can be temporarily interrupted when the lift head of the lift is in contact with the lifting point of the underbody and the bearing surface bears the appropriate remaining weight of the vehicle, at which point the wheel fasteners securing the wheel to the hub can be pre-loosened (wheel removed) or tightened (wheel installed) without rotation of the wheel. Once the wheel fasteners are sufficiently loosened or tightened, the lift raising or lowering process may continue. In other cases, if it is detected that the wheels have been adequately braked, or otherwise prevented from rotating, there is no need for any interruption in the lifting or lowering process.

After the vehicle is lifted by the lift to lift a wheel from the ground or other support surface, the wheel may be removed, serviced and reinstalled, or the wheel may be transported away and replaced with a previously serviced wheel, or a spare wheel, or a new wheel. In either case, as shown in fig. 19-23, the wheel 26 will be automatically gripped by the wheel gripping subsystem in preparation for removal. As shown in fig. 19 and 20, three gripping claws 78 are mounted in the front of the robot tool in an equally spaced circular array. Each grip jaw has a pair of cylindrical rollers 80 coaxially mounted on a shaft 82, the axis of the shaft 82 being generally parallel to the tool operating axis. More than one roller 80 is used for each gripping jaw 78 in order to better match the gripping jaw to the profile of the tread 84 of the tire 26 or to more securely grip the tread 84. The cross-section of the tread 84 may be curved or one side of the tread may wear more than the other based on the original design and service wear of the tire. Thus, by using two or more rollers 80, the contact between the gripper and the tread can be improved. In other alternatives, the two rollers may be tapered with a smaller taper angle, or mounted with a flexible connection between them to allow the axes of rotation of the two rollers to not be perfectly aligned. The surface layer of the roller may be a resilient material to enhance the gripping interface between the gripping claw 78 and the tire tread 84. As shown in fig. 43, one of the rollers 80 on at least one of the grippers is connected to a rotation motor 90, and the rotation motor 90 is driven to rotate the roller on the gripper 78 when needed, thereby reversing the rotation of the wheel 26 being gripped. As will be described later herein, the wheel may be rotated slowly to facilitate tire inspection or other related maintenance, or may be driven to rotate at a higher speed during detection and correction of dynamic wheel imbalance.

One end of each shaft 82 is secured to a bracket 92, which bracket 92 has a support plate or tab that supports the shaft 82. Each carriage 92 is mounted to slide back and forth radially along a corresponding bracket 96, the brackets 96 being mounted on respective prongs of a three-prong plate 98. Each of the three brackets 92 is independently driven by a respective linear motor 100 to move the three gripping jaws 78 in unison to increase or decrease the pitch radius of the circular array in which the gripping jaws are located. Increasing the pitch radius allows the wheel 26 to be accommodated within the circular array, while decreasing the pitch radius allows the gripper 78 to move toward the tread 84 of the wheel to grip the tire 86. In one embodiment, three linear motors 100 have built-in displacement sensors, and the displacement of each gripper from a coordinated starting point is measured by the displacement sensors, and the three grippers 78 can be moved independently to grip the wheel 26. The control system will calculate the position of the target wheel axis and then adjust the position of the robot tool operational axis to align it with the wheel axis. In an alternative embodiment, the linear motor does not have a built-in displacement sensor, but rather uses a wire cable to perform a "compare" function. Two of the three brackets are slave brackets and are connected to the "master" bracket by a wire cable. The movement of the wire cable may transfer the displacement of the slave carrier to the comparator on the master carrier where the displacement of the three carriers is compared. If the displacement of one of the carriages is delayed, the driving of the other two carriages is stopped until the displacements of the three are equal. This way the circular array of gripping claws can be incrementally adjusted so that the circle on which the array is located remains coaxial with the axis of operation of the robotic tool. FIG. 52 is a flow chart illustrating operation of the wheel alignment and proximity control module.

As shown in fig. 23 and 23A, a tread contact sensor 102 mounted between the rollers 80 of each gripper 78 is used to detect the direction of deviation of the wheel center axis relative to the tool operating axis. If only one of the tread contact sensors 102 is activated during the radially inward movement of each sensor pad 104, this means that the associated gripping claw 78 is closer to the wheel than the other two gripping claws. In response, the control system moves the operating shaft to equalize the spacing of each gripping claw 78 from the tread 84, while also progressively moving the gripping claws 78 toward the tread 84 to achieve a grip on the wheel. If the head of the sensor 102 comes into direct contact with the tire 86 of the rotating wheel, the sensor 102 may be damaged. When the sensor pad 104 comes into contact with the tread 84, it can trigger the tread contact sensor 102 and can absorb dynamic impacts of the wheel. As shown in fig. 22, similar sensors 103 and sensor pads 104 are mounted on the carriage 92, and a similar method is also used during movement of the gripping subsystem toward the outer sidewall of the vehicle tire. The sidewall sensor 103 is triggered when the sensor pad of the sidewall sensor 103 comes into contact with the wheel sidewall during the approach and contact of the robotic tool with the wheel sidewall. In fact, the above-mentioned manoeuvre for the wheel side wall should precede the manoeuvre for the tyre tread. Other types of sensors, such as non-contact proximity and distance sensors (optical, ultrasonic, etc.), may also be used to monitor the progress of such incremental proximity control techniques and their analysis.

During operation (fig. 20), the robotic tool moves to a set position in front of the target wheel 26 and projects a centering laser beam 105 along the operational axis toward the wheel. At the same time, the machine vision system analyzes the images of the wheel and laser spot, calculates the offset between the laser spot and the wheel center, and the inclination between the axis of the wheel and the operational axis, which are used to calculate the path of approach and its pointing direction of the tri-fork plate 98. The chassis and support plate are then driven accordingly to move the dropout 98 towards the wheel position and align the axis of operation of the robotic tool with the axis of the wheel. As shown in fig. 21, as the gripper assembly approaches the wheel, the grippers undergo the necessary radial movement to insert each gripper into the cavity between the wheel and the body, based on analysis of the machine vision system of the in-situ image data of the wheel and body, and the corresponding stored image data. A similar sequence may be used to access and hold wheels that are not mounted on a vehicle, such as new wheels stacked in a dispensing device. As shown in fig. 21, depending on the offset and inclination between the robot tool operating axis and the wheel axis, the robot tool will correct the position and inclination of its operating axis to substantially align the tool operating axis with the wheel axis.

Subsequently, three sidewall proximity sensors 103, the ends of which are shown in fig. 22, and three tread proximity sensors 102, the ends of which are shown in fig. 23, are needed to achieve more precise positioning. As shown in fig. 22, as the robotic tool approaches the wheel, one (or both) sidewall sensors 103 will be triggered first. The robotic tool then continues to move toward the wheel, but the orientation of the robotic tool is adjusted appropriately to restore a small separation between the triggered sidewall sensor and the wheel sidewall. When all three side wall sensors are triggered, the forward movement of the robotic tool is stopped, at which point alignment of the robotic tool operating axis with the axis of the wheel is achieved. While the robotic tool is properly positioned relative to the tire sidewall, three gripping claws in the tire well are moved radially inward toward the tread (fig. 23). Again, one (or both) tread proximity sensors 102 will be triggered first. Subsequently, the grippers continue to move inward, but the position of the robot needs to be adjusted appropriately so that a small spacing is maintained between the triggered tread proximity sensor and the tread. When all three tread proximity sensors 102 are activated, proper positioning of the gripper is achieved. At this point, the gripping claws continue to move for a short, controlled stroke in order to grip the wheel sufficiently tightly for subsequent maintenance operations, including removal of the wheel. Fig. 53 is a flowchart showing the operation of the wheel-grip control module.

Co-pending U.S. patent application 16104792, describes the use of robotic wheel maintenance tools to install and remove wheel fasteners. As shown in fig. 1-4, the exemplary fastener handling unit 14 is mounted on a support platform 40 having a set of parallel spindles 106, each rotatable about its longitudinal axis, distributed in a circular array. A socket 108 at the front end of each spindle is used to grip and rotate a threaded fastener 110, such as a wheel nut, the threaded fastener 110 being configured to engage the threads of a corresponding threaded fastener, such as a stud mounted on the hub member. The rear end of each mast 106 is connected to a motor 116 via a universal joint 114 to rotate the mast 106 about its axis. The adjustment mechanism 118 is used to synchronously vary the "deployment" of the spindles. In operation, to remove the wheel 26, the fastener removal unit 14 may be used to automatically sleeve the sleeve 108 over the wheel fastener 110 on the vehicle and unscrew the wheel fastener from the corresponding fastener on the hub. Similarly, to install the wheel, the fasteners may be gripped on the sleeves by the fastener removal unit and automatically tightened onto corresponding fasteners on the hub. To effect the installation or removal of the wheel fastener, the fastener-removing unit 14 is required to perform various actions with respect to the wheel, to move its whole or parts between different positions, or to change its orientation between various different directional angles, in order to perform the wheel fastener installation or removal operation. Some of these actions are automated by the action of components such as motors and bracket devices within the fastener assembly and disassembly unit, as described in U.S. patent application 16104792. Since the fastener handling unit 14 is mounted on the support platform 40, other of these above-described actions of the fastener handling unit 14 may be obtained by manipulation of the support platform 40.

Once the wheel 26 is fully gripped, whether the wheel is mounted on the vehicle or not, the wheel may be serviced accordingly by the robotic tool. In the latter case, to remove the wheel, the fastener removal unit 14 may be activated to remove a wheel fastener such as a nut, and the removed fastener 110 may then be stored in a fastener storage subsystem 15, as shown in FIGS. 24-32. The fastener 110, which is removed from its secured position on the wheel, is first held in the fastener sleeve 108. As shown in fig. 27, the magnetic attraction of the small magnets 120 integrated into the sleeves 108 holds the fasteners 110 in the respective sleeves. As shown in fig. 28 and 29, to transfer fasteners 110 from the sleeves to the fastener storage subsystem 15, the sleeves 108 are moved together radially from an initial position (fig. 28) just after removal to a final position (fig. 29) in which the fasteners 110 are distributed in a circular array having a radius equal to a predefined storage ready radius. As shown in fig. 26, each of the four storage stations 122 of the storage subsystem 15 has five wheel nut storage receptacles, with the receptacles of each storage station being mounted in a circular array distribution at a storage ready radius. The storage station 122 is mounted on a plate 126, which plate 126 is rotatable about an axle 128 mounted on the tri-fork plate 98. The distance from the center of the circular array in which the storage seats of each storage station are located is the same from the axis of the shaft 128. In this manner, any one of the storage stations may be rotated to a position in which its central axis is aligned with the centerline of the sleeve array. The plate 126 is rotated to a position in which the circular array of storage seats 124 on an optional storage station 122 is aligned with the circular array of sleeves 108. Each fastener is arranged so that when a selected storage station is in the rotated position, a storage receptacle of the array of storage receptacles of that storage station can be aligned with a corresponding sleeve of the array of sleeves.

As shown in fig. 30-32, trifurcated plate 98 is mounted on parallel shaft 132, parallel shaft 132 is mounted on support platform 40, and trifurcated plate 98 is slidable. The tri-fork plate 98 may be driven by the moving rod 133 of the linear motor 130 to move in direction B (fig. 30) to move the storage station 122 toward the sleeve 108 until the fastener 110 gripped by the sleeve 108 contacts and engages the corresponding storage seat 124 (fig. 31). Each storage receptacle 124 has an electromagnet thereon which is used to pull a fastener 110 from a sleeve to a storage position after the receptacle 124 has been brought into contact with the fastener. The linear motor 130 then releases the drag on the trident plate 98 and the spring 131 pushes the trident plate 98 back forward, so that the fastener 110 is pulled out of the sleeve 108 and remains locked on the storage seat 124. The plate 126 is then rotated about the shaft 128 to place each storage station 122 in the standby position. The electromagnet is then maintained in an energized state to ensure that the fasteners on the storage receptacle 124 do not fall out of their storage receptacles 124 until they are reused to install a wheel. In an alternative embodiment, a permanent magnet is mounted in each storage receptacle and an electromagnet is mounted in the sleeve. In an alternative embodiment, electromagnets are mounted on both the storage receptacle and the sleeve. Further, in another alternative embodiment, the spacing of adjacent reservoirs 124 is set to the spacing of adjacent sleeves when each sleeve is fully radially retracted. Alternatively, the spacing of adjacent reservoirs 124 may be set to any value within the allowable variation range of adjacent sleeve spacing, and each sleeve may be adjusted to a radial position that matches the fixed pattern of the reservoir as the fasteners are transferred. By modifying the storage stations or using plates 126 having different configurations, the number of storage receptacles at each storage station can be changed to match the different configuration parameters of the different wheels. Furthermore, the number of storage stations may also be varied as required in actual use. Although the configuration shown in the figures has a maximum storage capacity of only 20 wheel nuts (i.e., 4 wheel fasteners with 5 nuts per wheel), the maximum storage capacity of wheel fasteners can vary from model to fully meet the application requirements; for example, many cars use 4 or 5 fasteners for the wheels and heavy duty trucks and semi-trailers use as many as 12 or more fasteners for the wheels. As another example, for quick maintenance, all wheels of a first vehicle may be removed in advance and await a new wheel, during which the robot may service another vehicle, thus requiring a greater fastener storage capacity for the storage subsystem. When a wheel is installed, the stored wheel fasteners are removed from the fastener storage station and the process used to secure the wheel to the hub of the vehicle is essentially the reverse process. In another embodiment of the fastener storage subsystem, each storage station is mounted to a plate and is distributed in circular arrays with the centers of the circular arrays coincident. When it is desired to transfer fasteners from the sleeves to the magazine, the spindles of the fastener removal unit are deployed to match the circular array of sleeves to the circular array of selected fastener magazines. FIG. 54 is a flowchart of the operation of the fastener storage control module.

Tire inspection subsystem

For a wheel 26 that is free to rotate on its hub, maintenance operations can be performed on it even though it is still mounted on the vehicle. In this case, the wheel on the vehicle can be driven to rotate in reverse by activating the motor on the gripper to rotate the corresponding roller on the gripper. Alternatively, if one of the wheels mounted on the vehicle is not free to rotate, the powertrain of the vehicle may be operated to drive the wheel in rotation. If one of the wheels mounted on the vehicle is not able to be rotated at all, or if the wheel needs to be removed from the vehicle for other purposes, it can be removed from the vehicle in the operational steps described above. The wheel 26 should be held by the wheel holding subsystem 18 whether or not the wheel is mounted on the vehicle so that components of the wheel inspection subsystem 20 can be brought to an operational position near the wheel 26 in preparation for performing an inspection operation.

After a wheel 26 is successfully gripped by the gripping claw 78, the wheel may be driven to rotate at a slow speed, or intermittently to acquire data from the wheel, and the condition of the wheel and tread is monitored by a lighted camera 135 mounted on or near the gripping claw 78, the lighted camera 135 being part of the machine vision system which is part of the control system. The image of the wheel 26 is automatically compared to stored images and other data of the control system to determine and record the presence and location of anomalies such as bumps, nails, stones, scratches and cuts. In addition, conditions such as the depth of the remaining tread pattern, whether the tread wear is uniform, and whether the tread is damaged can also be analyzed and determined in a similar manner. A camera with a light source for monitoring the tread pattern is mounted with the tread contact sensor 102. When a wheel is held, the inner side wall of the wheel, e.g., the side of the wheel closer to the interior of the vehicle, is more difficult to detect. To monitor the condition of the wheel inboard wall, a wheel side wall camera 134 is used as shown in fig. 20, which is in a standby position. The camera 134 is mounted on a hinged bracket 136 and the motor 138 can extend and retract the bracket 136 and rotate the bracket to bring the camera 134 to an operative position in which the inside surface of the wheel can be imaged. To inspect the inside surface of the wheel, the camera 134 is first moved forward a distance along the axis of the gripper where it is located and then rotated through an angle to a working position where it can photograph the inside wall of the wheel. After the inspection is completed, the carriage 136 moves back to the standby position in the reverse order. The tire sidewall camera 140, mounted on the bracket 142, is used to detect the condition of the tire outer sidewall. Fig. 48 illustrates an exemplary flow chart of steps that may be required to be performed during a wheel inspection process. Fig. 55 is an operational flow diagram of the wheel inspection control module.

Tire pressure subsystem

As shown in fig. 33 to 35, the robotic tool has a subsystem 22 for measuring tire pressure and driving or releasing air to correct the tire pressure when the tire pressure is below or above the recommended pressure. For this maintenance operation, it is not necessary to remove the target wheel 26 from the vehicle or rotate it relative to the vehicle, since once the robotic tool 8 is within normal communication range, the control system with the machine vision system will operate the tire pressure subsystem to direct its associated sub-components onto the air nozzle needle of the wheel. Once in place, the tire pressure subsystem 22 performs the following operations: holding, rotating and taking down the needle valve cover to measure the tire pressure; driving or releasing air to increase or decrease tire pressure to recommended values; the needle valve cover is positioned and screwed down again; and finally, the tire pressure subsystem 22 is restored to its standby position. The flexible movement positioning capability provided by the drive motors of the chassis 10, the tool support platform 40 and the tire pressure subsystem allows tire pressure monitoring and maintenance operations to be performed regardless of the rotational position of the wheels.

Fig. 34 shows the back of the robotic tool with the components of the tire pressure regulating subsystem 22 mounted on the bracket 146. The bracket 146 is mounted on a vertical wall 148 integral with the support platform 40. The rotation motor 150 can rotate the carrier 146 about the robot tool operation axis D by driving the pinion gear 152 and the driven gear 154. Linear slide 158 is part of support 146 and carriage member 156 is mounted on linear slide 158 and is slidable along linear slide 158. The carriage member 156 may be driven back and forth in direction E by the linear motor 160 and stopped at a desired position. The rotation motor 162 can drive a bracket member 157 mounted in an angular movement to move to a desired inclination angle F. An air pressure unit 164 and a dust cap remover 166 are mounted on the bracket member 157 in close proximity to each other with the supports of the two units parallel to each other and to the tilting direction F. The dust cap remover 166 has an operating tube with two opposing jaws that open outwardly when the operating tube is fitted over the dust cap of the wheel needle to hold the dust cap so that it can be rotated. The gripping claws may be lined with a resilient gripping material or other forms of resilient spring gripping may be used. The rotation motor 172 may rotate the dust cap handle tube and screw the dust cap out of or onto the wheel needle 144. The air pressure unit 164 is pneumatically connected to the air pipe, the pressure sensor, the valve, the air pump, and a pneumatic control unit (not shown) of the control system through an opening 174 for measuring the tire pressure and delivering air of a desired pressure to the wheel needle 144 or releasing air from the wheel needle 144. A camera mounted on the robotic tool may be used to identify the location and orientation of a particular wheel needle valve to move the tire pressure subsystem through proper operation of the chassis and backer plate motors, and

motors

160, 162, 172, to enable the tire pressure subsystem to be aligned with the wheel needle valve 144. In operation, bracket 146, and the components thereon, will move the valve mounted thereon to a first position for removal of the dust cap from the wheel needle using dust cap remover 166, and then to a second position where tire pressure is measured and air can be driven or released through the connection of air pressure unit 164 to the wheel needle.

Fig. 33 and 34 show the chassis 10, the support plate 40 and the tire pressure subsystem 22 of the robot tool, while the other components are not shown. As shown in fig. 33, the tire pressure unit in the standby state is located beside the target wheel 26 to be maintained. Initially, it is unlikely that axis D will initially be aligned with the wheel axis, and therefore the motors of chassis 10 and support plate 40 are operated until the two axes are aligned. As shown in fig. 34, the motors are operated as needed to adjust the position and azimuth of the bracket and support plate to place the dust cap remover coaxially over the wheel needle valve dust cap (fig. 35). The dust cap remover is then rotated by the rotation motor to unscrew the dust cap, and then the dust cap is held in the holding claw of the dust cap remover. The air pressure unit then moves backwards, translates sideways to align the pressure nozzle with the wheel pin, and then moves axially forwards to press the pressure nozzle against the outer ring of the wheel pin until the pressure nozzle sealingly engages the outer ring. A control program is then initiated to check the tire pressure and, if necessary, pump air into or release air from the tire until the recommended tire pressure is reached. Attachment port 174 is then moved axially rearward to clear the wheel air tap. Thereafter, the robotic tool is again moved rearwardly and again translated laterally to align the dust cap remover with the wheel needle valve outer ring. The dust cap remover is then axially advanced to press the gripped dust cap onto the air tap and the rotary motor is activated to tighten the dust cap onto the air tap until the desired torque is achieved, whereupon the air pressure unit can be removed leaving the dust cap behind. Fig. 58 is a flowchart of the operation of the tire pressure regulating control module.

Dynamic wheel balancing subsystem

As shown in fig. 36-42, the wheel servicing robot tool 8 has a wheel dynamic balancing subsystem 24 that is capable of performing dynamic balancing operations on the wheel 26 that has been removed by the aforementioned gripping subsystem. As shown in fig. 38, the wheel dynamic balancing subsystem includes a first back plate 176 mounted to the yoke plate 98 by a bracket 178. A second backing plate 180 is coaxially mounted on plate 176 by a narrow slot and pin arrangement, and plate 178 is adjustable in position circumferentially relative to plate 176 to a limited extent. The center of plate 176 has a circular opening and spoke plates 178 have scalloped openings that are needed to accommodate the circumferential adjustment described above to allow a fastener-removing unit (not shown) to pass completely through spoke plates 178 to remove fasteners from, or install fasteners onto, a wheel.

As shown in fig. 38, the wheel dynamic balancing subsystem 24 has an operating arm 182 with a platen assembly 184 mounted on the operating arm 182, as well as a number of ancillary mechanisms that are required during the wheel dynamic balancing test and correction process. The motor 186 can drive the operating arm 182 to oscillate in the X-direction, and a linear motor can drive the operating arm to reciprocate in the Y-direction.

One function of the operating arm 182 is to shift the platen assembly 184 between an "off-axis" standby position, as shown in fig. 38 and 40, and an "on-axis" operating position, as shown in fig. 42, in preparation for a wheel dynamic balancing operation. As shown in fig. 40, during the transfer process, the operating arm moves the platen assembly and mounting bracket of the platen assembly away from the wheel 26 held in the gripping claw 78.

Another function of the operating arm 182 is to remove the wheel center cap from the wheel. The wheel center cover is a cover mounted to the wheel center by spring clips. The wheel center cap protects the axle nut and bearing from dust and other foreign objects during normal road use. In order to make the wheel mounted in a manner consistent with the requirements for performing dynamic wheel balancing operations, the wheel center cap must be removed from the wheel. To remove the wheel center cover, the operating arm is appropriately manipulated to move one end of a threaded shaft member of the pressure plate assembly 184 toward the wheel (fig. 41), which pushes the center cover against the force of the spring catch, ejecting it from the wheel. A central cover gripping mechanism (fig. 46 and 47) is mounted on the other side of the trifurcated plate. Before the top cover is ejected, the operating rod of the central cover gripping mechanism is driven by the linear motor to a position that can align the gripping head with the center of the wheel. When the wheel center cap is ejected from the wheel, it is gripped and held by the gripping head and remains there until the dynamic balancing of the wheel is completed. Currently, commercially available wheel center covers come in a variety of different forms, sizes and configurations. It is anticipated that as the maintenance of the wheels of a vehicle by robots becomes more common, the design of the center cover will become standardized. In one form, the wheel center cap has a ferromagnetic core therein and the gripper has an electromagnet therein which can be used to magnetically attract and hold the wheel center cap when it is ejected from the wheel.

Once the wheel center cover is removed and the pressure plate assembly 184 is aligned with the axis (fig. 41), the operating arm 182 is further manipulated to move the pressure plate assembly 184 along the tool operating axis toward the bit assembly 192 (fig. 42). As shown in fig. 44, the platen assembly 190 has a drum 194 and a flange 196 that are integrated. A bearing 198 is fixed inside the drum, the inner race of which is fixed to the larger diameter head end of the threaded shaft 200. The head of the shaft 200 has a drive recess 202 to accommodate the drive head of the impact motor mounted on the operating arm 182. When the drum assembly is in the standby or service position, the pins 204 integral with the drum flange 196 are received in corresponding holes 206 in the cage 190. The holes 208 in the pins 204 may receive the plunger of an electromagnet that may be moved into or out of the holes 208 to secure the drum 194 to the retainer or to release the drum 194 from the retainer 190. As shown in FIG. 45, bit assembly 192 has a main shaft 210 with a radial thrust bearing 212 secured to the main shaft 210 at a central location and supported on a flange 214. A conical head 216 having a central bore is mounted for free rotation on a needle bearing 218 secured to the head of the shaft 210. The center of the drum 194 incorporates a threaded shaft 200 and the central bore 220 of the conical head 216 has a corresponding internal thread. In a setup for a dynamic balance test operation, the drive head of the rotary impact motor rotates the drum shaft 200 through the recess 202 to be screwed into the bore 220 of the bit to clamp the wheel between the drum and the bit. In an arrangement for dynamic balancing test operation, bit assembly 192 may be driven by linear motor 222 toward wheel 26 being held, with shaft 210 constrained to move in a direction parallel to the tool operating axis by engagement of pin 224 with slot 226.

In the setup for the dynamic balance test operation, contact between the drum shaft 200 and the cone head 216 may be detected using a machine vision system built into the robot tool, or may be detected by an increase in current to the spin impact motor 234, since the shaft movement when obstructed would result in an increase in current to the spin impact motor 234. Upon contact between the drum shaft 200 and the cone head 216, the rotary impact motor 234 drives the shaft 200 within the drum 194 to rotate, threading the shaft 200 into the bore 220, and the wheel rim is sandwiched between the cone head 216 and the drum 194. During standby and movement to the operating position, the pins 204 of the drum assembly 184 are inserted and secured in the holes 206 of the cage, which are locked in the holes 208 by the electromagnet movable core located in the holes. After clamping the drum 194, wheel 26 and bit 216 together, the electromagnet is energized to release the pin 204 on the drum from the hole 206. Subsequently, the operating arm 182, which removes the platen assembly, returns to its standby position. After the wheel dynamic balance test is performed, the step of removing the platen assembly from the wheel is substantially reversed from the above-described process.

Once the wheel is clamped as previously described, the drum, wheel, bit assembly may all be driven by the motor-carrying gripper (fig. 43) to rotate at low or high speeds as required for operation. Alternatively, in dynamic balancing tests, when the wheel is required to rotate at a relatively high rotational speed, a larger roller may be installed, separate from or in place of the motor of the gripper, whose rotation is capable of producing a counter-rotation of the wheel for dynamic balancing tests.

The debris remover 228 is mounted on the operating arm 182 (fig. 38), and use of the debris remover 228 requires coordinated operation of the tire inspection subsystem 20 to identify the presence and location of debris and similar objects on the tread of the wheel 26 as it rotates at low speeds. Once the presence of debris is found, the debris is removed so that its weight does not interfere with the subsequent dynamic balancing of the wheel. The gravel remover comprises a pick-up or strut 230 having a tip that can be guided by the operating arm into a primary groove, such as a diagonally extending secondary groove, in the fore-aft direction on the tread by coordinated driving and control of the motors of the operating arm 182. Adjacent to the pick-up tip is an interface which is pneumatically connected to a vacuum pump (not shown) which is used to draw loose debris through the air tap into a storage bin.

An "old" weight removal head is also similarly mounted on the operating arm 182, which can be removed prior to the wheel dynamic balance test, or upon detection of a wheel dynamic imbalance. To remove the old weight, the control system compares the image of the rim produced by the camera with the stored image of the corresponding rim without weight to identify the location and type of the old weight. The operating arm 182 then guides one weight removal head to a position close to the rim surface and the wheel is also rotated to bring the old weight against the edge of a chisel that is part of the old weight removal head. Once the two come into contact, the operating arm moves axially rearward to pull the old weight down from the rim. The dropped weights are collected in a box in a suitable location.

For dynamic balancing tests, the power grip 78 will rotate at a higher speed to enable a correspondingly faster rotation of the wheel. Once the wheel has rotated to the desired speed, the gripper 78 is lifted from the tread 84 to allow the wheel 26 to rotate freely. The spindle 210 of the bit assembly has a rotary encoder (not shown) for displaying the angle of rotation of the bit, and thus the angle of rotation of the wheel, so that the rotational position of the wheel can be correlated with wheel vibration data generated by the control system during a dynamic balance test. Any of a number of commercially available vibration analysis subsystems may be integrated into the robotic tool control system for collecting wheel imbalance data. The vibration sensors for such a vibration analysis subsystem may be mounted, for example, at the mount 178, while their monitoring system may measure the x, y and z-axis forces and calculate the degree of dynamic imbalance and its direction. The wheel dynamic imbalance can be resolved into forces and moments acting on the inner and outer two planes of the wheel rim. The dynamic imbalance information, along with the stored or captured wheel dimension information, is used to determine the exact weight of the weight needed to dynamically balance the wheel, and its mounting location on the wheel rim. Fig. 56 and 57 are flowcharts illustrating the operation of the dynamic wheel balancing module.

The operating arm 182 has an old weight removal head, a rim cleaning head, a weight selector and a weight application head thereon. The tool heads may be mounted on an operating arm in a manner similar to a turret lathe and powered by associated motors under the control of a control system with the cooperation of a machine vision system. The operating arm 182 is mounted in a base fixed to the robot tool holder and is telescopically movable back and forth to enable the tool head to be moved to a desired radial position according to the radius of the rim. The operating arm may also be oscillated on its base to allow each tool head to be moved to a position at the flanges inboard and outboard of the rim. By coordinating the wheel rotation with the operation of the operating arm 182, the rim cleaning head can be moved to the calculated mounting location of the new weight, where it will spray cleaning fluid to the new weight mounting location and clean using the rotatable pad. Thereafter, the weight applying head on the operating arm takes the weight out of the weight storage box, transfers it to the mounting position in the correct direction, and then presses it on the rim surface so as to fix it in the correct position by the back adhesive on the weight. Weights are typically secured near the inboard and outboard flanges of the rim to achieve dynamic balancing. Finally, the wheel itself can rotate about its central axis. Since the angular position of the wheel is known from the real time output of the rotary encoder during the dynamic balance test, the weight applying head can be brought together accurately with the application position of the required weight on the rim. The balancing weight storage box can contain balancing weights with different weights and can also contain standard weights. In the latter case, multiple weights may be used to achieve the calculated weight. As previously described, another function of the manipulator arm 182 is to move the camera mounted thereon behind the wheel being held by the holding subsystem in order to inspect the inside of the rim.

Although the wheel maintenance robotic tool described above incorporates the chassis subsystem 10, the tool support subsystem 12, the fastener installation/removal subsystem 14, the fastener storage subsystem 15, the lifting subsystem 16, the wheel gripping subsystem 18, the wheel surface inspection subsystem 20, the tire pressure regulating subsystem 22, and the wheel dynamic balancing subsystem 24, in other embodiments of the invention, the wheel maintenance robotic tool may include only one or some of these subsystems as hardware components and its corresponding control system, as well as control software or control modules corresponding to its subsystem hardware. For example, in certain embodiments, the tire pressure regulating subsystem is not included in the wheel maintenance robot tool; in other embodiments, the wheel dynamic balancing subsystem is not included in the wheel maintenance robot tool.

Other variations and modifications of the described robotic tool will be apparent to those skilled in the art, and the foregoing description and illustrations of the embodiments of the invention are not intended to be limiting. In accordance with the principles of the present invention, there are numerous alternative embodiments of the invention which fall within the scope of the invention.

Claims

1. What is claimed is:

a robotic tool comprising a chassis, and at least one wheel servicing subsystem supported on the chassis, the wheel servicing subsystem having an axis of operation, and a subsystem interface component engageable with the wheel interface component, the wheel servicing subsystem interface component being engageable with the wheel interface component to permit servicing of a wheel by operation of the wheel servicing subsystem, the robotic tool further comprising a control system to control operation of the wheel servicing subsystem to perform the wheel servicing.

2. The robotic tool of claim 1, wherein the chassis has rollers configured to support the chassis on a support surface, and respective first and second roller drives configured to drive the first and second rollers to rotate about a substantially horizontal axis to change the position of the operational axis.

3. The robotic tool of claim 2, wherein the roller drives are independent of each other, and the first and second rollers may have different rotational speeds and rotational directions from each other.

4. The robotic tool of claim 2, further comprising third and fourth roller drivers configured to each independently drive the respective first and second rollers to rotate about a vertical axis to change a drive direction of the rollers.

5. The robotic tool of claim 1, further comprising a tool support platform positioned above and coupled to the chassis by a coupling, the tool support platform capable of supporting at least one of the wheel maintenance subsystems; the robotic tool further comprises a motor capable of adjusting the attachment, said motor being capable of varying the distance of said tool support platform from the chassis, thereby varying the position of said operational axis.

6. The robotic tool of claim 5, further comprising a motor for changing an orientation of the tool support platform relative to the chassis, thereby changing a position of the operational axis.

7. The robotic tool of claim 1, wherein the wheel maintenance subsystem is a wheel gripping subsystem having at least three grippers that can be deployed to grip the outer tread of the wheel to be maintained, the grippers being located on a circle centered on the operational axis.

8. The robotic tool of claim 1, wherein the wheel servicing subsystem is a tire inspection subsystem.

9. The robotic tool of claim 8, wherein the tire inspection subsystem includes at least one camera mounted with at least one of the grippers.

10. The robotic tool of claim 1, wherein the wheel maintenance subsystem is a tire pressure measurement and conditioning subsystem.

11. A robotic tool as claimed in claim 10, wherein the interface portion of the tire pressure measurement and adjustment subsystem is mounted on a support frame in a manner allowing it to rotate about the operational axis.

12. The robotic tool of claim 1, wherein the wheel maintenance subsystem is a wheel dynamic balancing subsystem.

13. A robotic tool as claimed in claim 12, further comprising a clamping assembly for clamping a wheel to be serviced at the centre of its rim, the clamping assembly being mounted in a manner allowing it to rotate about the operational axis.

14. The robotic tool of claim 1, wherein the wheel maintenance subsystem is a fastener installation/removal subsystem for installing/removing fasteners to/from a wheel mounting member to clamp/remove a wheel to/from the wheel mounting member, the wheel maintenance subsystem having parallel rotatable spindles with respective sockets for engagement with wheel fasteners, the parallel rotatable spindles being distributed in a circular array having a center on an operational axis.

15. The robotic tool of claim 1, wherein the wheel maintenance subsystem is a fastener storage library.

16. The robotic tool of claim 15, wherein the magazine has a storage station having a plurality of fastener storage receptacles distributed in a circular array, the storage station being rotatable about an installation position to move the storage station from a standby position to an operative position in which the circular array of fastener storage receptacles is centered about an operative axis.

17. The robotic tool of claim 1, further comprising a lifting subsystem for lifting a portion of the vehicle for removal or installation of a wheel to be serviced.