Powered omnipad platform

Abstract

A motor driven omnidirectional treadmill allows users to walk, jog, or run in any direction. When the treadmill is coupled with computer-generated immersive environments users can maneuver their way on-foot through 360-degree VR environments of infinite expanse and scope. The treadmill includes a bobbin made up of a walking surface disposed around a circular arrangement of support omniwheels. Drive omniwheels on the outside of the bobbin are configured to translate the walking surface.

Description

POWERED OMNIPAD PLATFORM CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of US patent application 17 / 282,346 filed April 1, 2021 which is a National Phase application of PCT / US2019 / 054371 filed October 2, 2019, which in turn claims benefit and priority to US provisional patent applications: 62 / 740,008 filed October 2, 2018 and 62 / 777,944 filed December 11, 2018. This application also claims benefit and priority to US provisional patent applications: 63 / 296,476 filed January 4, 2022, 63 / 394,601 filed August 2, 2022, 63 / 399,352 filed August 19, 2022, and 63 / 406,070 filed September 13, 2022. The disclosures of all of the above patent applications are hereby incorporated herein by reference.SUMMARY

[0002] The OmniPad is an omnidirectional treadmill that allows users to walk, jog, or run in any direction. When the OmniPad is coupled with computer-generated immersive environments users can maneuver their way on-foot through 360-degree VR environments of infinite expanse and scope.

[0003] The OmniPad™ is an Omni-Directional locomotion Input device specifically intended for use in virtual reality immersive environments. The OmniPad™ is the primary component of the OmniPad Environment.

[0004] The OmniPad is made up of many parts and subassemblies. This document provides a general description of the operation and components of the OmniPad. Each section describes one or more inventions that will form the bases for utility patent applications.Brief Description of the Drawings

[0005] Figure 1 A Illustrates an isometric view of an omnidirectional treadmill, according to various embodiments of the invention.

[0006] Figure IB illustrates a cross-sectional view of the treadmill, according to various embodiments of the invention.

[0007] Figure. 1C illustrates a detailed view of the cross-section of Figure IB, according to various embodiments of the invention.

[0008] Figure 2 illustrates a locomotion surface, according to various embodiments of the invention.

[0009] Figure 3 illustrates a bearing support system, according to various embodiments of the invention.1

[0010] Figure 4 illustrates a motor drive system, according to various embodiments of the invention. The optional motor drive system being configured to drive and / or assist the revolving tread surface.

[0011] Figure 5 illustrates a smart tread design according to various embodiments of the invention. Optionally the fabric of the tread surface may be stiffened or loosened in certain areas, in real time, by the use of an electric Polyhedral assembly of the revolving tread surface, rather than implementing a single-skin tread.

[0012] Figure 6 illustrates a ferrous tread material, according to various embodiments of the invention. The ferrous tread material is designed to function as part of the magnetic levitation system, which will levitate the entire Spindle system to enable ease of revolution of the moving tread surface.

[0013] Figure 7 illustrates polarity of a ferrous tread material, according to various embodiments of the invention. The figure includes an exemplary illustration of the polarity configuration of the Ferrous tread surface within the magnetic levitation system.

[0014] Figure 8 illustrates an alternative configuration of a ferrous tread material, according to various embodiments of the invention. A secondary application of the Ferrous tread, for magnetically reducing the friction between the elastic tread and the inner locomotion platform; which is also magnetized with the opposite polarity.

[0015] Figures 9A and 9B illustrate a polyhedral configuration of a tread surface, according to various embodiments of the invention. Polyhedral assembly of the revolving tread surface, rather than implementing a single-skin tread has advantages. Polyhedral tread assembly is optionally produced with holes in the segments in order to reduce the stress on the individual components, and to allow frictional heat to ventilate from inside of the revolving tread.

[0016] Figure 10 illustrates a spring hinge, according to various embodiments of the invention. The illustration includes a spring hinge to allow bending and stretching between the polyhedral components as the segments move around the sides of the inner platform while in motion.

[0017] Figures 11 A and 1 IB illustrate single and multi-layered tread surfaces, according to various embodiments of the invention. Various embodiments include a single-skinned revolving tread surface, where the single skin may be comprised of multiple layers suiting the anti-friction requirements of the inner tread, while concurrently suiting the anti-slip requirements of the outer tread where the locomotion takes place. Figure 1 IB includes a cut-away close-up of multilayered single-skinned revolving tread material.

[0018] Figure 12 illustrates a top view of a multi-layered tread surface, according to various embodiments of the invention. The illustration includes a multi-layered single-skinned tread, wherein the inner layers do not necessarily need to be bonded.

[0019] Figure 13 illustrates air flow within a tread, according to various embodiments of the invention. Air levitation of the revolving tread in order to reduce friction on the interior locomotion surface; similar to a bellows or an air hockey table.

[0020] Figure 14A illustrates magnetic levitation of a tread, according to various embodiments of the invention. Magnetic levitations systems description; 1) the tread material may have ferrous characteristics, and the inner locomotion surface may have permanent or electromagnetic magnetism of opposite polarity, thereby raising the elastomer tread from the inner surface to minimize friction; 2) the inner locomotion platform may exude magnetism, and there may be opposing magnetism exuding from the base of the device, thereby raising the entire Spindle system via magnetic levitation minimizing friction on the under-mounted rollers.

[0021] Figure 14B illustrates a detailed view of the tread of Figure 14A, according to various embodiments of the invention. The illustration includes a cut-away close-up view of magnetic tread and repelling inner locomotion surface magnets.

[0022] Figure 15 illustrates an inner locomotion surface, according to various embodiments of the invention. Ball bearing encircled inner locomotion surface, which enables freedom of movement of the spheroid revolving tread.

[0023] Figure 16 illustrates a ball bearing rig, according to various embodiments of the invention.

[0024] Figure 17 illustrates an adapted ball bearing rig, according to various embodiments of the invention.

[0025] Figure 18 illustrates a bearing retainer assembly according to various embodiments of the invention.

[0026] Figure 19 illustrates a roller assembly including a plurality of motor drives, according to various embodiments of the invention.

[0027] Figure 20 illustrates details of an alternative roller assembly, according to various embodiments of the invention.

[0028] Figure 21 illustrates a magnetically levitated spindle, according to various embodiments of the invention.

[0029] Figure 22 illustrates a cross-sectional view of a magnetic levitation system, according tovarious embodiments of the invention. The illustration includes both the Spindle and the Spindle support system.

[0030] Figures 23A and 23B illustrates alternative magnetic levitation systems, according to various embodiments of the invention.

[0031] Figure 23B illustrates the detail and polarity configuration of both the Spindle and the Spindle support system, according to various embodiments of the invention.

[0032] Figure 24 illustrates a cross-sectional view of an alternative spindle support system, according to various embodiments of the invention.

[0033] Figures 25 and 26 illustrate a detailed view of a section of Figure 24- A, according to various embodiments of the invention.

[0034] Figure 27 illustrates an omni- wheel spindle support configuration, according to various embodiments of the invention. In various embodiment the Omni-wheel Spindle supports configuration; omni-wheel rigs affixed intermittently to the base of the device will support the Spindle unit while concurrently allowing the tread surface to revolve freely in any direction.

[0035] Figure 28 illustrates a segmented inner locomotion platform, according to various embodiments of the invention. A segmented solid inner locomotion platform that expands outwards equally in all directions for the purpose of fitting the inner platform snugly inside of the spherical revolving tread; useful for initial assembly of the device, as well as for periodic adjustments to the fitting of the revolving tread. Sections may expand via a hydraulic system that may be activated by remote control and powered by a wireless charging mechanism.

[0036] Figure 29 illustrates an injection system, according to various embodiments of the invention. Injection of substance into spherical locomotion tread that solidifies and is able to be formed into the locomotion surface.

[0037] Figure 30 illustrates an internal locomotion tread drive system, according to various embodiments of the invention. The internal locomotion tread drive system includes assistive or driving motors configured to be controlled wirelessly and powered by inductive charging.

[0038] Figure 31 illustrates a cross-sectional view of a drive system, according to various embodiments of the invention.

[0039] Figure 32 illustrates an adaptation of omni-wheels, according to various embodiments of the invention. Adaptation of omni wheels, or Mecanum wheels, affixed intermittently around the stationary base of the device, similar to the bearing blocks, wherein these wheels simultaneously support and stabilize the revolving circular tread surface while still allowing therevolving tread to move in any direction.

[0040] Figure 33 illustrates a cross-sectional view of the system of Figure 32, according to various embodiments of the invention.

[0041] Figure 34 illustrates an omni directional motor, according to various embodiments of the invention. Example of the omnidirectional motor that will be a part of a series of similar motors comprising the motor drive system. Omnidirectional motors will be affixed intermittently around the base of the device, driving and / or assisting the movement of the revolving tread surface; based upon real time data describing where the user is on the device and in the virtual environment.

[0042] Figure 35 illustrates use of an omni-directional motor in a drive system, according to various embodiments of the invention.

[0043] Figure 36 illustrates a cross-sectional view of the system of Figure 35, according to various embodiments of the invention.

[0044] Figure 37 illustrates a motor drive option, according to various embodiments of the invention. Option for a motor drive system where two motors drive a ball, which in turn contacts the revolving tread surface in order to assist and / or drive the revolution of the tread. This option may be used in conjunction with the motor drive option illustrated in Figure 4.

[0045] Figure 38 illustrates a ball transfer motor configuration, according to various embodiments of the invention.

[0046] Figure 39 Illustrates views of an omnidirectional treadmill, according to various embodiments of the invention. This shows an option for the motion tracking system placement and configuration, which will relay the locomotion data of the user in real time both to the VR environment and to the motor drive system, and optionally to the Tilting and Varying Surface Robotic Platform described below. This combination of systems will implement predictive artificial intelligence, where the device will attempt to predict, based upon bio-kinetic analysis, the user’s locomotion, and the motor drive system will respond by keeping the user centered on the circular locomotion surface. Other uses of the predictive analysis and motion tracking include enhanced interfacing of the user into the virtual environment.

[0047] Figures 40 and 41 illustrate various views of a tilting omnidirectional treadmill, according to various embodiments of the invention. These views include a side view of the undermounted Tilting Robotic Platform option, which will respond in real time to the user’slocation in the virtual environment, wherein when the user encounters an incline in the VR environment the platform, and in turn, the locomotion surface, will tilt upwards in whatever direction the user is moving in order to emulate walking or running up a hill. The reciprocal is also true for emulating declines in the VR environment. Side view of the Varying Surface Platform option, which may work in conjunction with the Titling mechanism described in Figure 40. This option will emulate elevation, and raising and descending in the virtual environment.

[0048] Figure 42 illustrates a top view of 3 axis motion control using 120-degree trines and drive axis that pass through the platform center according to various embodiments of the invention.

[0049] Figure 43 is a perspective view of 18 single plane omni wheels according to various embodiments of the invention.

[0050] Figure 44 shows a perspective view, and a front view, of a dual plane omni wheel according to various embodiments of the invention.

[0051] Figure 45 illustrates an exemplary balloon in the process of being molded according to various embodiments of the invention.

[0052] Figure 46 illustrates the molding of a balloon by low pressure injection molding within a multi-part tool according to various embodiments of the invention.

[0053] Figure 47 illustrates two parts of the mold of Figure 46.

[0054] Figure 48 illustrate a balloon within the mold of Figure 46, partially unmolded.

[0055] Figure 49 illustrates an exemplary manual process of stretching a balloon over a bobbin according to various embodiments of the invention.

[0056] Figure 50 illustrates an exemplary bobbin complete with balloon cover according to various embodiments of the invention.

[0057] Figures 51 and 52 illustrate an exemplary process of sealing the hole in an injection molded balloon according to various embodiments of the invention.

[0058] Figure 53 illustrates a top view schematic representation of an OmniPad showing exemplary tracking cameras according to various embodiments of the invention.

[0059] Figure 54 illustrates a perspective view of an OmniPad including an exemplary video display according to various embodiments of the invention.

[0060] Figure 55 illustrates a cross-sectional view of an omnidirectional treadmill according to various embodiments of the invention.

[0061] Figure 56 illustrates a top view of a bobbin of an omnidirectional treadmill without thebladder, according to various embodiments of the invention.

[0062] Figures 57 and 58 illustrate top views of a bobbin of an omnidirectional treadmill, with and without the bladder, showing drive and stabilization omniwheels arranged around the bobbin according to various embodiments of the invention.

[0063] Figure 59 illustrates a perspective view of the arrangement of Figure 58.

[0064] Figure 60 illustrates a side view of the arrangement of Figure 58.

[0065] Figure 61 illustrates a perspective view of a single plane omni wheel according to various embodiments of the invention.

[0066] Figure 62 illustrates a front view of the single plane omni wheel of Figure 61.Detailed Description

[0067] Referring to Figures 1A and IB and 1C.

[0068] Tread: The tread will be fabricated using highly flexible and extremely durable rubber-like material like Silicone, EPDM or natural rubber which can be motivated by a person walking or running. The tread is manufactured in such a way that it is a single sphere like embodiment, which is then wrapped over the spindle, entirely encasing the spindle and bearings. This material is flexible enough to enable a 360- degree change in direction around the spindle.

[0069] Spindle - Walking Platform: The Spindle will be approximately 200mm thick and approximately 1 - 2 meters diameter. The Top Surface is designed to support the user during operation.

[0070] Edge Bearings: The edge bearings reduce the friction on the tread (bladder) as it rotates around the spindle. The bearings enable the free 360-degree mobility of the bladder.

[0071] Bobbin: Referring to Figure 2. The bobbin assembly is the combination of the tread (bladder), spindle, edge bearings and lubrication as shown below. The bobbin assembly allows the user to be in the virtual environment and move as if they are in the natural world. This assembly is supported by the support bearing blocks.

[0072] Support Bearing Block: Referring to Figure 3. The bearing support system allows the bobbin assembly to move with little or no friction, as shown below. This system supports the bobbin during operation and translates the loads to base system.

[0073] Motor Drive System: Referring to Figure 4. The Motor drive system is used to assist the users' natural locomotion, and to relay the locomotion gestures to thevirtual environments, which will update in real time, as shown below.

[0074] Tread Materials: The tread will be fabricated using highly flexible and extremely durable rubber-like material like Silicone, EPDM or natural rubber which can be motivated by a person walking or running. The tread is manufactured in such a way that it is a single sphere like embodiment, which is then wrapped over the spindle, entirely encasing the spindle and bearings. This material is flexible enough to enable a 360- degree change in direction around the spindle. The tread will be manufactured in such a way that it is a continuous surface, which is then wrapped over the spindle to entirely encase the spindle and bearings. In various embodiments the tread is formed from a balloon. The tread is also referred to herein as a bladder or walking surface.

[0075] Smart Adaptive Tread Material: The Smart Adaptive Tread Material will alter, in real time, the material's properties when a voltage, electrical field, current or magnetic field is applied. When the voltage, current or field is applied to a specific area of the surface just that area's material properties will change. For example, as the current or field is applied to the material the material will become more flexible or stiff in that localized area only. Referring to Figure 5. Area 1 = Walk area, drive area or support area, stiff area to limit slip or buckling in the material Area 2 = Flexible area.

[0076] Ferrous Tread Material: Bobbin Support Referring to Figures 6 and 7.Currently, magnetic bearings are commonly used in industrial applications such as turbomolecular pumps, or even mag-lev trains. The Ferrous tread material allows for the omnidirectional locomotion surface to be magnetically polarized, thereby, attracting or repelling magnetic or electromagnetic forces. This allows the tread to magnetically levitate the bobbin assembly. In Figure 7 Area 1 = Magnetically polarized tread Area 2 = Mag-Lev bearing block.

[0077] Friction Reduction: Referring to Figure 8, another use for the ferrous tread material is to be suspend away from the spindle, therefore lowering the frictional forces. By using the magnetically repelling forces and the elasticity of the tread itself, the tread will separate from the spindle providing a small gap, thus lowering the friction between the spindle and the tread. In Figure 8, Area 1 = Negatively charged outer surface Area 2 = Positively charged inner tread surface; Area 3 = Positively charged outer spindle surface.

[0078] Goldberg Polyhedral Tread Material: Referring to Figures 9A Another embodiment of the bladder is comprised of discrete segments. These segments typically take the shape ofeither hexagon or pentagon polyhedrons which are edge-connected to form a sphere.

[0079] Polygon segments used in any of the Goldberg polyhedral spheres will be made from a flexible material. The individual polyhedral elements need to stretch in any arbitrary direction a minimum of 150% of its original dimension in any planar direction. Categories of materials that possibly fulfill this mission are thermoplastic rubbers, or stretchable fabric like elastane (Spandex).

[0080] The Goldberg construction uses hexagons and pentagons. There are other geometries available as well, such as parallelograms. These alternate constructions are not Goldberg polyhedra.

[0081] Referring to Figures 9B and 10, a further enhancement of the Goldberg segments is inclusion of a hole pattern. Inclusion of holes permits the structure to stretch with lower material stress for equal strain. These patterns are made from Hexagon and Pentagon Shapes like a soccer ball. Elastomer shapes stretch to fill the gaps. Spring hinge pins allow for bending on the hinge lines.

[0082] Multilayer Skin Tread: Referring to Figures 11 A and 1 IB, the Multilayer Skin Tread use thin layers of different tread materials, coating and textures to have specific properties on the different layers. The inner layer needs to be extremely low friction such as Teflon (PTFE) coating, as it is sliding on the spindle surfaces. The outer layer preferentially needs to have a higher friction, or needs to have traction so the user's foot surface and the motor drives will be able to move the tread surface in any direction. The inner and outer surfaces of each layer may or may not be bonded together. Working with multiple thin layers will create a stronger tread, and will also aid in the overall assembly of the entire bobbin unit.

[0083] Referring to Figure 12. In various embodiments, layers may or may not be bonded together, layers may or may not be of the same materials or material properties, and optionally inside layers do not have to be bonded or sealed (areas 1-4 below). Outside layers may be selected for friction with the feet or footwear of a user. Inside layers may be selected for reduced friction of motion of the tread surface against the supporting structures. Outside layers (e.g., layer 5) may, therefore, have a greater coefficient of friction than inside layer 1.

[0084] FRICTION REDUCTION SYSTEM: The surface between the Spindle and the Tread is a very high friction force area. To alleviate these friction forces, we havedesigned different alternative methods. Although the primary solution to high friction force is employment of a low friction layer such as Teflon™ (or PTFE), other solutions are available.

[0085] Air Bearing: Referring to Figure 13, the Air bearing spindle uses a similar concept to an air hockey table. An air hockey table uses small air jets to levitate a puck on the surface. The air bearing spindle has a porous spindle surface or uses air jets to separate the tread material from the spindle surface. This will minimize or eliminate the friction. The arrows in the image below represent the airflow applying a force to the tread / bladder. This driving force causes the tread to expand like a balloon away from the spindle, thus lowering the friction between the two elements.

[0086] Magnetic Levitation: By utilizing the magnetically polarized tread material and a permanent or electromagnet, the tread material can be levitated above the spindle surface minimizing or eliminating the tread-to-spindle contact, thereby reducing or eliminating the friction forces.

[0087] Referring to Figures 14A and 14B. Area 1 = Magnetically Polarized Tread; Area 2 = Permanent or electromagnetic spindle; Area 3 = Inductive power supplied to spindle for electromagnetic spindle; Area 4 = Exterior surface of tread has an opposing magnetic charge to the inner surface. Area 5 = Interior surface of the tread is polarized differently than the spindle to create a separation of the tread from the spindle. This is to eliminate (or minimize) the friction between the spindle and the t read. Area 6 = The spindle magnet can be permanent or electromagnet. The electromagnet can be powered by an inductive power coil similar to wireless cell phone charging. Control of the electromagnet is done through wireless communication.

[0088] Dry & Wet Lubrications: Dry and wet lubricants are used to reduce the friction between the tread and the spindle. These lubricants are also used to dissipate some of the thermal energy created by the friction.

[0089] Ball Transfer Bearing: Referring to Figures 15 and 16, this is the most straightforward means of friction reduction around the edges as it transmits motion onto the rolling contact of a bearing. Balls, rollers or rollers plus balls around the outside accomplish this task. On the top surface, this may be accomplished by employing a bed of omni-rollers lined up to form a surface. Omni-rollers need to be sized small enough to form a surface with a large number of foot contact points, but large enough toemploy bearings of reasonable size.

[0090] Referring to Figure 17: Area 1 = Edge ball bearing; Area 2 = Magnet embedded inside the edge bearing; Area 3 = Magnet embedded inside the ball transfer base unit; and Area 4 = recirculating bearings.

[0091] Referring to Figure 18: Area 1 = Edge ball bearing, which is similar to a ball transfer unit with smaller ball bearings behind the main ball in contact with bladder (tread). Area 2 = Bearing retainer (may not be required) Area 3 = Spindle.

[0092] Roller-ball-socket unit: Referring to Figure 19, motion along the OmniPad periphery varies continuously. Motion vectors combine both vertical and horizontal motion. It is the most straightforward way to provide a rotational surface for vertical motion. Horizonal motion along the sides will need to rely on low sliding friction or bearing supported rollers.

[0093] From the cross section of Figure 20, we see the repeating bearing unit that rings the active surface. In this embodiment, we see a center roller with a ball. Closer inspection shows the roller mounted on a central ball bearing, which will transmit vertical bladder forces with high efficiency. The ball is mounted in a cup, and the cup is also mounted on a bearing.

[0094] When these units are stacked together around the periphery of the OmniPad, each ball fits into the socket of the next. Further, we see that each ball is held by two sockets, with each socket having its own bearing. The ball will rotate relatively freely, with some friction against the bearing cups because of the mounting angle. Separate segments permit varying vertical motion vectors to maximize the bearing- supported motion, as opposed to friction-supported motion. This type of repeating unit is driven from the outside of the OmniPad.

[0095] Referring to Figure 20. To preserve a secure ball mount and avoid interference of the roller segments, the above design employs straight versus curved roller segments. This design can be driven internally or externally as before. Advantages: fewer parts, more driving surface (for internal drive) and potentially less bladder stress due to larger roller diameter.

[0096] In Figure 19: Area 1 = Roller surface; Area 2 = Ball bearing allowing for free movement between rollers Area 3 = Optional motor drive system; and Area 4 = Roller mounting bracket.

[0097] In Figure 20, Area 4 = Ball bearing; Area 5 = Outer ball roller cup Area 6 = Inner roller; Area 7 = Bearings; and Area 8 = Optional motor drive belt.

[0098] Magnetically Levitated Spindle: Currently, magnetic bearings are commonly used in industrial applications such as turbomolecular pumps, or even mag-lev trains. The magnetically levitated bearing supports leverage on the technology that is used in other products to create a non- contacting bearing system that uses permanent magnet and / or electromagnets to magnetically levitate the bobbin assembly without any physical contact. Referring to Figures 21, 22, 23 A, and 23B, the magnetically levitated bearing supports eliminate any mechanical wear that the contact bearing create, and it eliminates friction. The OmniPad uses permanent magnets inside of the bobbin assembly, and electromagnets in the bearing block.

[0099] In Figure 23 A: Area 1 = Permanent magnet embedded into the spindle Area 2 = Permanent or electromagnet. In Figure 23B: Area 1= Magnetically polarized tread Area 2 = Mag-Lev bearing block.

[0100] Ball Transfer BearingBlock: Referring to Figures 24, 25, and 26, the ball bearing supports the bobbin assembly with a thrust bearing to allow for low friction to transfer the loads. The below images show how the ball bearing block interfaces with the bobbin assembly in vertical and axial loads. A minimum of 3 bearing blocks are required, while the images below show 4 bearing blocks. In these figures: Area 1 = Ball transfer units configured to support axial and radial loads. Motor drive can be integrated into the ball transfers.

[0101] Omni Wheel: Referring to Figure 27. Omni wheels of the standard (shown) or the Mecanum wheel type are used to support and stabilize the spindle assembly. No fewer than three points of contact are required for full stability, though six are depicted. Support nodes require wheel pairs: one for bottom and one for top. Either or both of these wheels may be powered to control surface movement.

[0102] As with other drive mechanisms, the surface velocity vector at the contact point of the roller is what determines roller drive velocity. Omni-wheels have the unique feature of driving only in the plane of the wheel, orthogonal to the drive axis. All other motion is passed through the rollers. Drive velocity at a given point is accomplished by revolving and driving only the motion vector that the roller canaddress.

[0103] Referring to Figure 27, the system is supported at 45 degrees above and below the center line by 3 to 8 pairs of support wheels. These support wheels can be used in tandem to drive the tread.

[0104] SPINDLE: The spindle provides the rigid surface for the user to operate on while providing a support structure for the edge bearings. The Spindle will be approximately 200mm thick and approximately 1 - 2 meters diameter. The Top Surface is designed to support the user during operation.

[0105] The difficulties in assembling the bobbin assembly in real world manufacturing has lead us to investigate solutions for this problem. To understand this more, we are inserting a disc (the Spindle) into a Tread (or Bladder), while stretching the bladder to very high loads in order to eliminate any wrinkling or bunching, and to evenly distribute the forces throughout.

[0106] Solid or Segmented Spindle: Referring to Figure 28, the segmented spindle takes a rigid solid spindle and breaks it into pieces that can be assembled inside the bladder. Once assembled, the spindle is then expanded (either manually or automatically) to the proper size and shape. In some embodiments, an otherwise solid spindle is broken into smaller pieces to assist in assembling the spindle into the bladder. Optional a ratcheting device to expand the spindle once assembled inside the bladder.

[0107] Alignment features

[0108] Inflatable Spindle: The inflatable spindle (See Figure 29 Area 1) allows for the spindle to be inserted into a small opening in the Bladder during the assembly process. The spindle is then filled with a media (Gas or liquid) to rigidize the spindle such that the loads (bearings and user's weight) are properly supported and managed. One of the major factors in this material is the low coefficient of friction.

[0109] DRIVE SYSTEM: Driving the Omni-Directional Treadmill can be accomplished via internal or external motors. The drive system is essential to overcome the high frictional forces that the tread experiences. These motors are typically controlled by circuits responsive to sensors that detect motion of a user standing on the treadmill. The circuits configured to keep the user centered on the treadmill as the user moves on various directions by walking or running, etc.

[0110] Internal Drive: Referring to Figure 30. This repeating unit places a drive13sprocket central to the roller and runs the drive belt internally. We see a recurring theme of separate sections. As before, the balls are mounted in sockets that are themselves free to rotate. A further variation, not shown, would be to connect all four central roller segments into one, and to put the bearing under the ball cup as seen in the previous design. The variation would drive more of the edge surface but would have more vertical friction shear.

[0111] Referring to Figure 31 : Area 1 = Roller surface; Area 2 = Ball bearing allowing for free movement between rollers; Area 3 = Motor drive system and Area 4 = Roller mounting bracket. Referring to Figure 20B: Area 4 = Ball bearing; Area 5 = Outer ball roller cup Area 6 = Inner roller; Area 7 = Bearings; and Area 8 = Motor drive belt.

[0112] Omni Wheel: Figures 32 and 33 illustrate six external omni wheels driving a surface. Omni-rollers on the bottom are connected to servo motors. Each omni roller drives only the motion vector tangent to the contact point. Motion transverse to the contact point passes through because of the roller construction. Omni-rollers on top typically serve to constrain the OmniPad fully in 3D-space. Further, upper rollers can be used to increase the contact force of the drive rollers. In theory, only three drive rollers are needed to address all top surface motion vectors.

[0113] Drive Wheel: Referring to Figure 35 A simple drive system can drive the tread from a series of motors mounted under the bobbin assembly. See isometric view in Figure 36. These motors are mounted on a rotary table to allow for motion in any direction. The images below show a motor system with 4 motors that are synchronized to move the tread while minimizing the adverse effects on the top user surface. In Figure 34, Drive system with a simple motor and wheel on a rotating table: Area 1 = Motor and encoder for main drive wheel; Area 2 = Motor and encoder for table rotation; Area 3 = Main Drive wheel, used to move the tread around the spindle Area 4 = Rotating Table; and Area 5 = Motor Base.

[0114] Ball Transfer Drive System: Referring to Figures 37 and 38, the Ball Transfer Drive System uses 2 motors to drive a ball supported by bearings underneath. This allows the motors to drive the ball in any direction. This motor drive system can be placed into the Ball Transfer Bearing Blocks, or as a stand-alone motor system in the center of the bobbin assembly.[OOH5]CONTROL SYSTEM: Referring to Figure 39, the control system design controls the speed and direction of the tread surface. It ensures that the user has a safe and entertaining experience while using the omnidirectional moving surface. The control system utilizes user motion feedback, through cameras, force feedback through the safety harness and feedback from the drive motor system. These different feedback systems provide validation and confirmation of the user and operation of the OmniPad system.

[0116] Motion Feedback: Referring to Figure 39, using Cameras pointed at the user or other sensors, the OmniPad control system can determine the position, direction and speed of the user. As the user changes any or all of the above locomotion characteristics, the motion feedback system responds to and can predictively adjust the OmniPad tread surface accordingly. The Motion feedback system can also identify where the users body parts are located providing additional feedback into the virtual environment. By recognizing the users' body position and velocity, the motion feedback system calculates where the user’s next step will be placed and the center of mass. This functionality will assist in the overall effectiveness of the immersive experience.

[0117] Motor Feedback: By monitoring the motors' direction (forward or reverse), velocity (via motor encoder or steps) and angle of attack (rotational direction relative to ground) we can control the actual position and motion of the tread. By monitoring the motor current and encoder position the system can monitor any system faults on the tread (i.e., the tread not moving, when we expect it to be moving).

[0118] User Force Feedback: Sensors on the user harness, footwear, and / or on the treadmill provide accelerations, directional and angular forces that the user generates while operating the OmniPad. These accelerations and forces are processed and converted into responses by the OmniPad tread to change direction or increase or decrease the speed while the tread is moving.

[0119] PIVOT TABLE SYSTEM

[0120] Walking or running on flat ground is adequate, but there are also inclines and declines in the real world that can be replicated by the OmniPad system. Being able to simulate walking up, down or across hills; or even to have the ability to simulate moving15across different types of surfaces like gravel, sand, or mud will greatly enhance the virtual experience.

[0121] Tilting Robotic Platform: Referring to Figure 40, by using a combination of linear actuators and sensors (load cells, position indicators) the locomotion surface can be actuated in order to change the tilt or pitch of the tread surface. By implementing the Tilting Robotic, or Stewart Platform the OmniPad can simulate to the user moving up, down or across slopes in the virtual environment.

[0122] Varying Surface Emulation: Referring to Figure 41, when the user is immersed in the virtual world, with visual, audio and locomotion, the OmniPad Control System can make small adjustments to the angle and elevation of the tread surface to simulate a wide variety of surfaces, such as gravel, sand or mud.

[0123] The OmniPad control system along with the immersive VR environment manipulates the users' sensory perception to give the feel of walking or running on different surface types and densities. The combination of the linear position indicators, and the load cells allows the control system to calculate the position of each of the user's feet. Thus, defining the accurate and subtle changes required to simulate the varying surface types.

[0124] Powered OmniPad Platform

[0125] 3 axis motion control using 120-degree trines and drive axis that pass through the platform center

[0126] In Figure 42 the 3 trines are clockwise 0-120 degrees, 120-240 degrees and 240-360 degrees. Trine 1 starts with Primary drive wheel A and runs up to Primary drive wheel B, Trine 2 starts with Primary drive wheel B and runs up to Primary drive wheel C, and Trine 3 starts with Primary drive wheel C and runs up to Primary drive wheel A.

[0127] The 3 primary drive wheels (A, B, C) could in theory drive the continuous surface on their own. Redundant drive wheels are added to spread out the drive forces. Inverse Drive wheels (-A, -B, -C) use the same motor input as their respective Primary drive wheels (A, -A), (B, -B), (C, - C) but in the reverse direction.

[0128] The input to drive the system is based on cartesian coordinate system (illustrated in the center of the image as 0, 90, 180, 270). The X and Y input is converted to a polar coordinate system in order to drive each primary drive wheel using the following equations:

[0129] Motor A speed = COS of the polar angle in degrees

[0130] Motor B speed = COS of 120 - the polar angle in degrees

[0131] Motor C speed =negative COS of 60 - the Polar angle in degrees

[0132] Continuously recycling support structure consisting of 18 "single-plane" omniwheels spaced evenly around a circular plate.

[0133] Figure 43 shows 18 “single plane” omniwheels. 6 wheels allows for 3 wheels to be 120 degrees apart and each of the 3 wheels to have a polar opposite. This defines the drive system to be a multiple of 6 wheels, 6, 12, 18, 24 etc... For this particular diameter 18 wheels minimizes the unsupported space between the wheels.

[0134] Note that the use of single plane omniwheels instead of dual plane omniwheels allows for driving the inside wheels through the moving surface using a similar outside single plane omniwheel. Not all inside wheels need to be driven. Being that the moving surface can move in all directions the wheels that are not driven will move as the surface is pulled across them.

[0135] Figure 44 shows a dual plane omniwheel for reference, in both a perspective view and a front view. Note the lack of consistent rolling contact if two wheels are rolled against each other due to the gaps between rollers in each plane. The dual plane omniwheel has a set of rollers along the circumference of the wheel in two planes. There are essentially 2 sets of rollers in parallel planes around the circumference of the wheel. The issue is the two sets of wheels are clocked out of phase from each other to create a continuous rolling surface when rolling on a flat surface. Since only one omniwheel is driving another, through the walking surface material, we cannot have this great of a discontinuity from one roller to the next. The single plane omniwheels nest the 2nd set of rollers inside the first set of rollers within the same plane. This makes for a very small discontinuity from roller to roller.

[0136] Spherical elastomer balloon that is 90% spherical or better for the purpose of stretching over a continuously recycling support structure, then "capping" to create a continuous surface.

[0137] If the balloon is not nearly spherical, it will not run smoothly. It will pull to the shortest side due to uneven tension. Figure 45 shows a 14” diameter balloon while still on the core mold (spherical) and after removal from the core mold, also showing the passage hole. The balloon preferably is not off of spherical by more than about 10% by any 2 measured diameters. If the smallest measured diameter is 10”, the largest measured diameter needs to be no greater than 11”. This can also be thought of as + / - 5%. The material of the balloon needs to be very tough and extremely elastic. A suitable example is a platinum cure silicone Shore A 03 durometer with astretch to failure ratio of 7. Other materials have similar properties, for example, Latex, TPU, TPE, etc. could be used with the proper production equipment. The balloon will be understood to be the same structure as the bladder, or walking surface, when incorporated into an omnipad.

[0138] Molding of the balloon using a multi-part mold tool and low pressure injection molding.

[0139] Figure 46 illustrates the molding of a balloon by low pressure injection molding within a multi-part tool held together with clamps. Figure 47 shows two parts of the mold, while Figure 48 shows the balloon within the mold, partially unmolded. More specifically, the multi part mold tool, when assembled, defines a gap in the desired shape of a spherical balloon. There is a center spherical core with a single neck that is captured by 2 halves of an outer cavity then assembled to a lower cavity. The result is an outer wall surface and an inner wall surface between which a 2 part mix platinum cure silicone is injected using a low pressure (for example, 45psi), to fill the void and create the balloon. The outer cavity of the mold tool is then disassembled (split apart) so it can be separated from the balloon and spherical core. The balloon is then stretched off of the spherical core to yield a single piece spherical balloon. There are many alternative ways to make a spherical balloon, low pressure injection molding is but one example.

[0140] Stretching a balloon over a continuously recycling support structure.

[0141] Figures 49 illustrates a manual process of stretching a balloon over a bobbin, whileFigure 50 shows the bobbin complete with the balloon. It should be noted that the balloon can be purposefully marked or colorized during fabrication, or after fabrication and before stretching, or after stretching.

[0142] Sealing / capping the hole in the balloon required to stretch the balloon over the support structure to create a continuous uninterrupted surface.

[0143] Figures 51 and 52 show an exemplary process of sealing the hole that allowed the balloon to be stretched over the bobbin. First, the hole is stretched closed so there is almost zero stretch, then the edge of the hole is clamped to an inside structural plate, as seen in Figure 51, and then a puddle of silicone is poured into the hole on the plate, then cured. After curing the clamps are removed and the excess material is peeled off of the inner structural plate. This gives a sealed balloon wrapped over the omniwheel structure.

[0144] Motion tracking of "walking" subject to relocate the walking subject at or near the center of the walking area.

[0145] Figure 53 shows a top view schematic representation of an exemplary OmniPad. Thearrows in Figure 53 represent the location and direction of exemplary tracking cameras. Each camera can “see” the moving subject on the motion surface and output positional data to be used to move the circular motion surface in whatever direction is required to move the motion subject to the center of the motion surface. As few as one motion tracking camera will work. More cameras increase accuracy and sensitivity.

[0146] Motion control output (joystick, keyboard, mouse, VR / AR) from the walking surface control system to the gaming computer (PC, VR headset, etc.) to synchronize AR / VR environment motion to the walking subject's motions. i.e. simply walking on the surface drives the game motion.

[0147] The motion tracking input(s) that cause the motion surface to move the motion subject back to the center of the motion surface can also be output to VR headsets, gaming systems, PCs, etc. to “move” the subject within the AR / VR / Gaming environment in a synchronized manner. Figure 54 shows a perspective view of an OmniPad including a curved video display.

[0148] Alternatives for the number of active and non-active wheels.

[0149] Only 3 primary drive wheels are necessary to define the motion control. The Idling wheels to keep the walking surface from spinning about the vertical (Z) axis relative to the drive assembly can be as few as 1 , but 4 or more are preferred.

[0150] Alternatives for the number of redundant drive wheels.

[0151] The number of redundant drive wheels can be anything, but multiples of 6 make the most sense. Adding intermediate wheels is also doable.

[0152] Possible ranges of wheel diameters, (and for alternative sizes of the system. Perhaps ranges of ratios of wheel size to platform size.

[0153] Any diameter of drive wheel will work as they roll outside the walking surface. The goal however is to keep it as small as possible. 100mm diameter wheels are readily available, but 125mm diameter wheels would also work. As the platform size increases, the wheel diameters would scale as well. An exemplary maximum ratio of wheel size to platform size (diameter to diameter) is about 6:1, while a minimum would be 1: 1 as that would just be a spherical walking surface. As one gets closer to spherical, the easier everything is, however a 20ft diameter sphere would be required to get a usable walking surface and the goal is to keep it as small as possible.

[0154] Alternative ratios of motors / wheels.

[0155] The motor to wheels ratio distils down to minimum number of drive wheels vs minimum number of idle wheels to avoid clocking of the walking surface.

[0156] Figures 55-60 show additional illustrations of an omnidirectional treadmill according to various embodiments of the present invention. Figure 55 shows a cross-sectional view of a bobbin showing two support omniwheels surrounded by a flexible bladder. The support omniwheels are maintained in place by a support structure. Each support omniwheel defines a rotation axis that in the illustration is perpendicular to the plane of the drawing. The rotation axis of each support omniwheel is also tangential to a circle defined by the arrangement of support omniwheels. Outside of the bobbin, are a number of drive omniwheels in contact with the bladder, each drive omniwheel driven by a motor (not shown). Each drive omniwheel is disposed at one of the support omniwheels such that the bladder is compressed between each drive omniwheel and its respective support omniwheel. In addition to support omniwheels, disposed outside of the bobbin and also in contact therewith are optional stabilization omniwheels, as shown.

[0157] Figure 56 illustrates a top view of a bobbin of an omnidirectional treadmill without the bladder. This drawing shows a different perspective of the bobbin shown in Figure 43. Both show that the support omniwheels are arranged around a circle.

[0158] Figures 57 and 58 are top views of drive omniwheels and stabilization omniwheels arranged around a bobbin, according to various embodiments. Figure 57 includes the bladder while Figure 58 omits the bladder to show the support omniwheels within. Figure 59 shows a perspective view of the arrangement of Figure 58, while Figure 60 shows a side view of the same. In the illustrations there are 6 drive omniwheels each driven by a motor. Additionally, the illustrations show four stabilization omniwheels. The stabilization wheels each define a plane that is off-axis with respect to the center of the bobbin. The stabilization omniwheels are paired such that each stabilization omniwheel sits opposite its mate across the center of the bobbin, with their respective planes being parallel. Each stabilization omniwheel is arranged to be in contact with the bladder opposite a support omniwheel. The side view particularly shows that omniwheels can be disposed in a plane below a center horizontal plane defined by the bobbin in order to support the bobbin. Similarly, omniwheels can be disposed in another plane above the horizontal plane of the bobbin in order to hold down the bobbin. In various embodiments the omniwheels above the plane of the bobbin are drive omniwheels while the omniwheels below the plane of the bobbin are stabilization omniwheels, or vice versa, or there drive and stabilization omniwheels are disposed in both planes. In some embodiments, one of the stabilization omniwheels is configured to prevent rotation of the bobbin around a vertical axis of the bobbin in a clockwise direction and another of the stabilization omniwheel is configured to prevent rotation of the bobbin around the vertical axis in acounterclockwise direction.

[0159] Figures 61 and 62 show a single plane omniwheel both in perspective and edge-on.As shown, the single plane omniwheel includes interlocking rollers or have rollers spaced apart by a distance less than a length of each roller. This presents a roller on one omniwheel from locking between rollers on an opposing omniwheel. While this is illustrated for a single plane omniwheel, it also applies to dual plane omniwheels.

Claims

22CLAIMS mnidirectional treadmill comprising: a bobbin including a number of support omniwheels arranged in a circle and disposed within, and surrounded by, a flexible bladder, an axis of rotation of each support omniwheel being tangent to the circumference of the circle; and three drive omniwheels disposed outside of the bobbin, each of the drive omniwheels in contact with the bladder at one of the support omniwheels such that the bladder is compressed between each of the drive omniwheels and the respective support omni wheel. readmill of claim 1, wherein the flexible bladder includes a dynamic material configured to change shape in response to an electric or magnetic field. readmill of any one of the previous claims, wherein the flexible bladder includes a ferromagnetic material. readmill of any one of the previous claims, wherein the flexible bladder is configured to be dynamically more flexible at the circle of support omniwheels relative to a center of the circle. readmill of any one of the previous claims, wherein the support omniwheels and / or the drive omniwheels are single plane omniwheels. readmill of any one of the previous claims, wherein at least three of the drive omniwheels are configured to support the bobbin. readmill of any one of the previous claims, including 6 or 9 drive omniwheels.readmill of any one of the previous claims, wherein the bobbin includes a magnet configured to prevent the circle of support omniwheels from rotating around a center of the bobbin relative to the drive omniwheels. readmill of any one of the previous claims, further comprising two or four stabilization omniwheels, each stabilization omniwheel being disposed proximate to a respective support omniwheel. treadmill of any one of the previous claims, further comprising two or four stabilization omniwheels configured to prevent rotation of the bobbin around a vertical axis defined through the center of the bobbin. treadmill of any one of the previous claims, wherein any of the omniwheels includeinterlocking rollers or have rollers spaced apart by a distance less than a length of each roller. treadmill of any one of the previous claims, wherein three of the drive omniwheels are disposed below a horizontal plane of the bobbin and configured to support the bobbin. treadmill of any one of the previous claims, wherein the three drive omni wheels are disposed above a horizontal plane defined through the bobbin and configured to hold down the bobbin. treadmill of any one of the previous claims, further comprising 3, 4 or 6 omniwheels, each aligned with a respective support omniwheel and configured to support the bobbin. treadmill of any one of the previous claims, wherein each of the drive omniwheels includes 12 rollers. treadmill of any one of the previous claims, wherein one of the stabilization omniwheels is configured to prevent rotation of the bobbin around a vertical axis of the bobbin in a clockwise direction and another of the stabilization omniwheels is configured to prevent rotation of the bobbin around the vertical axis in a counterclockwise direction. treadmill of any one of the previous claims, wherein three of the drive omniwheels are disposed in a first plane and three of the drive omniwheels are disposed in a second plane.

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