Powered Omnipad Platform

Abstract

To provide a motorized omnidirectional treadmill that allows a user to walk, jog, or run in any direction. When the treadmill is coupled to a computer-generated immersive environment, the user is able to navigate their own path with their feet throughout a 360 degree VR environment of infinite breadth and scope. The treadmill includes a bobbin comprised of a walking surface arranged around a circular arrangement of supporting omni-wheels. A driving omni-wheel on the outside of the bobbin is configured to translate the walking surface.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of U.S. Patent Application 17 / 282,346, filed April 1, 2021, which is a national stage application of PCT / US2019 / 054371, filed October 2, 2019. This application claims the benefit of and priority to U.S. Provisional Patent Application 62 / 740,008, filed October 2, 2018, and U.S. Provisional Patent Application 62 / 777,944, filed December 11, 2018. This application also claims the benefit of and priority to U.S. Provisional Patent Application 63 / 296,476, filed January 4, 2022, U.S. Provisional Patent Application 63 / 394,601, filed August 2, 2022, U.S. Provisional Patent Application 63 / 399,352, filed August 19, 2022, and U.S. Provisional Patent Application 63 / 406,070, filed September 13, 2022. The entire disclosures of the above patent applications are incorporated herein by reference. Summary of the Invention

[0002] The OmniPad is an omnidirectional treadmill that allows users to walk, jog, or run in any direction. When combined with computer-generated immersive environments, the OmniPad allows users to navigate their own path with their feet throughout a 360-degree VR environment with infinite breadth and scope.

[0003] The Omnipad / OmniPad™ is an omnidirectional motion input device specifically designed for use in virtual reality immersive environments. The Omnipad / OmniPad™ is a fundamental component of the Omnipad environment.

[0004] The Omnipad is composed of a subassembly of many parts. This specification provides a general description of the operation and components of the Omnipad. Each section of this specification describes one or more inventions that form the basis of this application. [Brief description of the drawings]

[0005] [Figure 1] FIG 1A depicts an isometric view of an omni-directional treadmill, according to various embodiments of the present invention. FIG 1B depicts a cross-sectional view of an omni-directional treadmill, according to various embodiments of the present invention. FIG 1C depicts a detailed view of the cross-sectional view of FIG 1B, according to various embodiments of the present invention. [Diagram 2] 1 illustrates a motion surface according to various embodiments of the present invention. [Diagram 3] 1 illustrates a bearing support system according to various embodiments of the present invention. [Figure 4] 1 illustrates a motor drive system according to various embodiments of the present invention. Optional motor drive systems are configured to assist in driving and / or rotating a rotating tread surface. [Diagram 5] 1 illustrates a smart tread design, according to various embodiments of the present invention. Optionally, the tread surface fabric can be made regionally stiffer or softer in real time using an electrical polyhedron assembly on the rotating tread surface, rather than implementing a single-skin tread. [Figure 6] 1 depicts a ferrous tread material, according to various embodiments of the present invention, designed to function as part of a magnetic levitation system that levitates the entire spindle system, allowing the moving tread surface to rotate with ease. [Figure 7] 1 depicts the polarity of ferrous tread materials according to various embodiments of the present invention. This diagram includes an exemplary illustration of the polarity configuration of ferrous tread surfaces within a magnetic levitation system. [Figure 8] 1A-1C depict alternative ferrous tread material configurations according to various embodiments of the present invention. A second use of the ferrous tread is to magnetically reduce friction between the elastomeric tread and the inner moving platform. The inner moving platform is magnetized with opposite polarities. [Figure 9A]1 illustrates a polyhedral configuration of the tread surface according to various embodiments of the present invention. The polyhedral assemblage of the rolling tread surface has advantages over the implementation of a single-skin tread. The polyhedral tread assemblage is optionally provided with holes in sections to reduce stress on the individual components and release frictional heat from the interior of the rolling tread. [Figure 9B] 1 illustrates a polyhedral arrangement of a tread surface according to various embodiments of the present invention. The polyhedral assemblage of the rolling tread surface has advantages over a single-skin tread implementation. The polyhedral tread assemblage is optionally provided with holes in sections to reduce stress on the individual components and release frictional heat from the interior of the rolling tread. [Figure 10] 1 illustrates a spring hinge according to various embodiments of the present invention, including a spring hinge that allows bending and extension between the polyhedral parts while the sections move around the sides of the inner platform during movement. [Figure 11] FIG. 11A illustrates a single layer tread surface according to various embodiments of the present invention. Various embodiments employ a single skin rolling tread surface, which includes multiple layers to meet the anti-friction requirements of the inner tread while also meeting the anti-skid requirements of the outer tread where movement occurs. FIG. 11B illustrates a multi-layer tread surface according to various embodiments of the present invention. Various embodiments employ a single skin rolling tread surface, which includes multiple layers to meet the anti-friction requirements of the inner tread while also meeting the anti-skid requirements of the outer tread where movement occurs. FIG. 11B includes an enlarged cutaway view of the multi-layer single skin rolling tread material. [Figure 12] 1 illustrates a plan view of a multi-layer tread surface according to various embodiments of the present invention, the view including a multi-layer single-skin tread surface, the inner layers not necessarily being bonded together. [Figure 13] 1 illustrates airflow inside the tread according to various embodiments of the present invention. Air suspension of a rolling tread to reduce friction on the inner moving surface, similar to a bellows or air hockey table. [Figure 14]FIG. 14A illustrates magnetic levitation of the tread, according to various embodiments of the present invention. The magnetic levitation system is described as follows: 1) The tread material has ferrous properties and the inner motion surface has a permanent magnetic or electromagnetic effect of opposite polarity, so friction can be minimized by lifting the elastomeric tread from the inner surface. 2) The inner motion platform exerts a magnetic effect, and the magnetic effect emanating from the base of the device is opposite, so friction at the underlying rollers can be minimized by lifting the entire spindle system via magnetic levitation. FIG. 14B illustrates a detailed view of the tread of FIG. 14A, according to various embodiments of the present invention. This view includes a cutaway close-up of the magnetic tread and the repelling inner motion surface magnets. [Figure 15] 1 illustrates the inner motion surface according to various embodiments of the present invention. The ball bearings form the spherical inner motion surface, which allows the spheroidal tread to move freely. [Figure 16] 1 illustrates a ball bearing arrangement according to various embodiments of the present invention. [Figure 17] 1 illustrates an adapted ball bearing arrangement according to various embodiments of the present invention. [Figure 18] 1 illustrates a bearing retention assembly according to various embodiments of the present invention. [Figure 19] 1 illustrates a roller assembly including multiple motor drives according to various embodiments of the present invention. [Figure 20] 13 illustrates details of an alternative roller assembly according to various embodiments of the present invention. [Figure 21] 1 illustrates a magnetically levitated spindle according to various embodiments of the present invention. [Figure 22] 1 illustrates a cross-sectional view of a magnetic levitation system, including both a spindle and a spindle support system, according to various embodiments of the present invention. [Diagram 23]Figure 23A illustrates an alternative magnetic levitation system according to various embodiments of the present invention. Figure 23B illustrates an alternative magnetic levitation system according to various embodiments of the present invention. Additionally, Figure 23B illustrates the details and polarity configuration of both the spindle and spindle support system according to various embodiments of the present invention. [Figure 24] 1 illustrates a cross-sectional view of an alternative spindle support system according to various embodiments of the present invention. [Diagram 25] 24B illustrates a detail of the portion enclosed by the dashed line in FIG. 24A, according to various embodiments of the present invention. [Figure 26] 24B illustrates a detail of the portion enclosed by the dashed line in FIG. 24A, according to various embodiments of the present invention. [Figure 27] 1A-1C depict omni-wheel spindle support configurations according to various embodiments of the present invention. In various embodiments, the omni-wheel spindle support configuration. The omni-wheel rigs, which are intermittently secured to the base of the device, support the spindle portion while allowing the tread surface to rotate freely in any direction. [Figure 28] 1 illustrates a segmented inner motion platform according to various embodiments of the present invention. The segmented solid inner motion platform expands outward equally in all directions for the purpose of fitting the inner platform snugly inside the spherical rolling tread. Useful not only for initial assembly of the device, but also for periodic adjustment to fit the rolling tread. The segments can be expanded via a hydraulic system. The hydraulic system can be activated by remote control and powered by a wireless charging mechanism. [Figure 29] 1 illustrates an injection system, according to various embodiments of the present invention, that allows a material to be injected into the spherical motion tread and solidify to form a motion surface. [Diagram 30]1 illustrates an inside moving tread drive system, according to various embodiments of the present invention, in which the assist or drive motor is wirelessly controlled and powered by inductive charging. [Diagram 31] 1 illustrates a cross-sectional view of a drive system according to various embodiments of the present invention. [Diagram 32] 1 illustrates the conformation of omni-wheels according to various embodiments of the present invention. Similar to bearing blocks, omni-wheels or Mecanum wheels are employed that are intermittently fixed around the stationary base of the device, and these wheels support and stabilize the rotating annular tread surface while allowing the rotating tread to move in any direction. [Diagram 33] 33 illustrates a cross-sectional view of FIG. 32 according to various embodiments of the present invention. [Diagram 34] 1 illustrates an omni directional motor, according to various embodiments of the present invention. An example omni directional motor is part of a series of similar motors that include a motor drive system. The omni directional motor is fixed intermittently about the base of the device to drive and / or assist the movement of a rotating tread surface based on real-time data describing the user's position on the device and within the virtual environment. [Diagram 35] 1 illustrates the use of an omni-directional motor in a drive system, according to various embodiments of the present invention. [Diagram 36] 36 illustrates a cross-sectional view of the system of FIG. 35 in accordance with various embodiments of the present invention. [Figure 37] 1 illustrates a motorized drive system according to various embodiments of the present invention. A motorized drive system option in which two motors drive the balls contact the rolling tread surface to assist and / or drive the rolling of the tread. This option may be used in conjunction with the motorized drive option described in FIG. 4. [Figure 38] 1 illustrates a ball transport motor configuration according to various embodiments of the present invention. [Figure 39]1 illustrates a diagram of an omnidirectional treadmill, according to various embodiments of the present invention. Also illustrated are installation and configuration options for a motion tracking system that relays real-time user motion data to both the VR environment and the motorized drive system, and optionally, the Tilting and Varying Surface Robotic Platform, described below. This combination of systems implements predictive artificial intelligence. The device attempts to predict the user's motion based on bio-motion analysis. The motorized drive system responds by attempting to keep the user at the center of the circular motion surface. Other uses of predictive artificial intelligence and motion tracking include improving the user's interface to the virtual environment. [Diagram 40] 1 illustrates an incline omnidirectional treadmill according to various embodiments of the present invention. [Diagram 41] 40 illustrates an inclined omni-directional treadmill, according to various embodiments of the present invention. The tilting robotic platform option located below, shown in side view, responds in real time to the user's position in the virtual environment. When the user encounters a slope in the VR environment, the platform, or motion surface, will tilt upward in whatever direction the user is moving to simulate walking or running up a hill. The reverse is true to simulate a downward slope in the VR environment. The changing surface platform, shown in side view, can work with the tilt mechanism described in FIG. 40. This option simulates high changes, ascents, and descents in the virtual environment. [Diagram 42] 1A-1D depict plan views of three-axis motion control using 120 degree trines and drive axes passing through the platform center, according to various embodiments of the present invention. [Diagram 43] FIG. 1 illustrates a perspective view of eighteen single-planar omni-wheels according to various embodiments of the present invention. [Diagram 44] 1A-1D depict perspective and front views of a dual-plane omni-wheel according to various embodiments of the present invention; [Diagram 45]1 depicts an exemplary balloon in the process of being molded in accordance with various embodiments of the present invention. [Figure 46] 1 illustrates the molding of a balloon by low pressure injection molding inside a multi-part tool according to various embodiments of the present invention. [Figure 47] It represents two parts of the mold of FIG. [Figure 48] 47 depicts a partially unmolded balloon inside the mold of FIG. 46. [Figure 49] 1 illustrates an exemplary manual process for stretching a balloon over a bobbin, according to various embodiments of the present invention. [Figure 50] 1 depicts an exemplary bobbin having a balloon cover thereover, according to various embodiments of the present invention. [Figure 51] 1 illustrates an exemplary process for sealing a hole in an injection molded balloon, according to various embodiments of the present invention. [Figure 52] 1 illustrates an exemplary process for sealing a hole in an injection molded balloon, according to various embodiments of the present invention. [Diagram 53] 1 illustrates a top view schematic of an Omnipad showing an exemplary tracking camera, in accordance with various embodiments of the present invention. [Figure 54] 1 illustrates a perspective view of an omnipad including an exemplary video display according to various embodiments of the present invention. [Figure 55] 1 illustrates a cross-sectional view of an omnidirectional treadmill according to various embodiments of the present invention. [Figure 56] 1 illustrates a top view of a bobbin of a bladder-less omnidirectional treadmill according to various embodiments of the present invention. [Figure 57] 1 illustrates a top view of a bobbin of an omni-directional treadmill with a bladder according to various embodiments of the present invention, showing the drive and stabilization omni-wheels positioned around the bobbin. [Figure 58]1 illustrates a top view of the bobbin of a bladder-less omni-directional treadmill according to various embodiments of the present invention, showing the drive and stabilization omni-wheels disposed around the bobbin. [Figure 59] 59 shows a perspective view of the device of FIG. 58. [Figure 60] FIG. 59 shows a side view of the device of FIG. 58. [Figure 61] FIG. 1 illustrates a perspective view of a single-plane omni-wheel according to various embodiments of the present invention. [Figure 62] 62 illustrates a front view of the single-plane omniwheel of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] Please refer to Figures 1A, 1B, and 1C.

[0007] Tread: The tread is made from a rubber-like material such as silicone, EPDM, or natural rubber that is highly flexible and extremely durable so that it can be set in motion by a person walking or running. The tread is made in the shape of a sphere, so that it wraps around the entire spindle, completely encasing the spindle and the bearings. The material is flexible enough to be able to rotate 360 ​​degrees around the spindle.

[0008] Spindle - Walking Platform: The thickness of the spindle is about 200mm and the diameter is about 1-2m. The upper surface is designed to support the user during operation.

[0009] Edge Bearings: Edge bearings reduce friction on the tread (bladder) as it rotates around the spindle. The bearings allow the bladder to move freely 360 degrees.

[0010] Bobbin: See Figure 2. As will be shown below, the bobbin assembly is a combination of tread (bladder), spindle, edge bearings, and lubricant. The bobbin assembly allows the user to be present in the virtual environment and move as if in the natural world. This assembly is supported by a support bearing block.

[0011] Support Bearing Block: See Figure 3. The bearing support system allows the bobbin assembly to move (almost) without friction as will be shown below. This system supports the bobbin during operation and transfers the load to the base system.

[0012] Motor Drive System: See Figure 4. The motor drive system is used to assist the user's natural movements and relay the movement gestures to the virtual environment, which updates in real time as shown below.

[0013] Tread Material: The tread is manufactured using a highly flexible and extremely durable rubber-like material such as silicone, EPDM, or natural rubber that can be set in motion by a person walking or running on it. The tread is manufactured in the shape of a sphere, so that it wraps around the spindle, completely encasing the spindle and the bearings. The material is flexible enough to be able to turn 360 degrees around the spindle. The tread is manufactured to wrap around the spindle with a continuous surface, completely encasing the spindle and the bearings. In various embodiments, the tread is formed from a balloon. The tread is also referred to herein as a bladder or walking surface.

[0014] Smart Adaptive Tread Materials: Smart adaptive tread materials change the properties of the material in real time when a voltage, electric field, current, or magnetic field is applied. When a voltage, current, or electromagnetic field is applied to a specific area of ​​the surface, only the material properties in that area change. For example, a current or electromagnetic field is applied to the material, causing it to become more flexible or stiffer only in that localized area. See Figure 5. Region 1 is the walking, driving, or support area, a stiff area that limits the slippage or buckling of the material. Region 2 is a flexible area.

[0015] Iron-based tread material: bobbin support. See Figures 6 and 7. Magnetic bearings are currently commonly used in industrial applications such as turbomolecular pumps or magnetic levitation trains. With iron-based tread material, the moving surface in all directions can be magnetically polarized to attract or repel magnetic or electromagnetic forces. This allows the tread to magnetically levitate the bobbin assembly. In Figure 7, region 1 is the magnetically polarized tread and region 2 is the magnetic levitation bearing block.

[0016] Reduced Friction: Referring to FIG. 8, another application of the ferrous tread material is to reduce frictional forces by suspending it away from the spindle. Using magnetic repulsion and the elasticity of the tread itself, the tread is able to move away from the spindle creating a small gap, reducing friction between the spindle and the tread. In FIG. 8, region 1 is the negatively charged outer surface, region 2 is the positively charged inner tread surface, and region 3 is the positively charged outer spindle surface.

[0017] Goldberg Polyhedral Tread Material: See Figure 9A. Another embodiment of the bladder includes discrete sections. These sections are typically in the shape of hexagonal or pentagonal polyhedrons that are joined at the ends to form spheres.

[0018] The polygonal segments used in the Goldberg Polyhedron Sphere are made of a flexible material. The individual polygonal elements must be able to stretch in any direction, and in any planar direction, a minimum of 150% of their original dimension. The categories of materials that might fulfill this designation are thermoplastic rubbers, or stretchable fabrics such as elastane (Spandex).

[0019] The Goldberg structure uses hexagons and pentagons. There are other geometric shapes that can be used, such as parallelograms. These alternative structures are not Goldberg polyhedra.

[0020] Referring to Figures 9B and 10, a further improvement to the Goldberg segment is the inclusion of hole patterns. The inclusion of holes allows the structure to stretch with lower material stress for the same strain. These patterns are made with hexagons and pentagons like a soccer ball. The elastomer shape stretches to fill the gap. Spring hinge pins allow bending on the hinge line.

[0021] Multi-skin tread: Referring to Figures 11A and 11B, a multi-skin tread uses thin layers of different tread materials, coatings, and textures with specific properties on different layers. The inner layer needs to be extremely low friction, such as a Teflon (PTFE) coating, to slide on the surface of the spindle. The outer layer needs to have higher friction or traction so that the surface of the user's foot and the motor drive can move the tread surface in any direction. The inner and outer surfaces of each layer may or may not be bonded to each other. Working in multiple thin layers creates a stronger tread and also helps ease assembly of the entire bobbin section.

[0022] Referring to FIG. 12, in various embodiments, the layers may or may not be bonded to one another. The layers may or may not be of the same material or material properties. Optionally, the inner layer may not be bonded or sealed (areas 1-4 below). The outer layer may be selected with consideration of friction with the user's foot or footwear. The inner layer may be selected to reduce friction of the movement of the tread surface against the support structure. Thus, the outer layer (e.g., layer 5) may have a greater coefficient of friction than the inner layer 1.

[0023] Friction reduction systems: The surface between the spindle and the tread is where the very high friction forces are experienced. To mitigate these friction forces, the applicants have designed various alternative methods. The basic solution to the high friction forces is the use of a low friction layer such as Teflon (or PTFE), but other solutions are available.

[0024] Air Bearings: Referring to Figure 13, air bearing spindles use a similar concept to air hockey tables. Air hockey tables use small air jets to lift the puck above the surface. Air bearing spindles have a porous spindle surface or use air jets to separate the tread material from the spindle surface, thus minimizing or eliminating friction. The arrows in the image below represent the air flow exerting a force on the tread / bladder. This driving force causes the tread to expand like a balloon, away from the spindle, thereby reducing friction between the two elements.

[0025] Magnetic Levitation: By utilizing a magnetically polarized tread material and a permanent magnet or electromagnet, the tread material can be levitated above the spindle surface, minimizing or eliminating contact of the tread with the spindle, thereby reducing or eliminating frictional forces.

[0026] Referring to Figures 14A and 14B, region 1 is the magnetically polarized tread, region 2 is the permanent or electromagnetic spindle, region 3 is the inductive power supplied to the spindle for the electromagnetic spindle, region 4 is the outer surface of the tread, which has an opposite magnetic charge to the inner surface. Region 5 is the inner surface of the tread, which has a different polarity than the spindle to separate the tread from the spindle. This is to eliminate (or minimize) friction between the spindle and the tread. In region 6, the magnet of the spindle can be a permanent magnet or an electromagnet. The electromagnet can be powered by an inductive power coil, like wireless charging of a mobile phone. Control of the electromagnet is done by wireless communication.

[0027] Dry and wet lubricants: Dry and wet lubricants are used to reduce friction between the tread and the spindle. These lubricants are also used to dissipate some of the heat energy generated by friction.

[0028] Ball Transfer Bearing: Refer to Figures 15 and 16, this is the simplest means of reducing end friction when transferring motion onto the rolling contacts of a bearing. Placing balls, rollers or rollers plus balls around the outside accomplishes this task. On the upper surface this can be achieved by employing a bed of omni-directional rollers aligned to form the surface. The omni-directional rollers need to be small enough in size to form a surface with many foot contact points, yet large enough to employ a reasonably sized bearing.

[0029] Referring to FIG. 17, region 1 is the edge ball bearing, region 2 is magnets embedded within the edge bearing, region 3 is magnets embedded within the ball transfer base, and region 4 is a recirculating bearing.

[0030] Referring to Figure 18, area 1 is the edge ball bearing. An edge ball bearing is similar to a ball carrier with a smaller ball bearing behind the main ball that contacts the bladder (tread). Area 2 is the bearing holder (not required) and area 3 is the spindle.

[0031] Roller Ball Socket: Referring to Figure 19, motion along the perimeter of the Omnipad is continuously variable. The motion vector couples both vertical and horizontal motion. This is the simplest way to provide a rolling surface for vertical motion. Horizontal motion along the sides must rely on low sliding friction or rollers supported on bearings.

[0032] From the cross section in Figure 20, we can see the repeating bearings which annularly surround the active surface. In this embodiment, we can see a center roller with balls. Looking more closely, the roller is mounted on a central ball bearing, which transfers the vertical bladder forces with high efficiency. The balls are mounted in cups which are also mounted on bearings.

[0033] These members are stacked around the perimeter of the omnipad, with each ball fitting into the socket of the next. Each ball is then held in two sockets, each with its own bearing. The balls rotate relatively freely, but due to the mounting angle, friction occurs with the bearing cups. The separation of the sections changes the vertical motion vector, allowing for maximum bearing-supported motion versus friction-supported motion. This type of repeater is driven from the outside of the omnipad.

[0034] Referring to Figure 20, the above design employs straight vs. curved roller sections to ensure a secure ball mount and avoid roller section interference. This design can be conventionally internally or externally driven. Advantages: fewer parts, more drive surfaces (if internally driven), potentially less bladder stress due to larger roller diameter.

[0035] In Figure 19, area 1 is the surface of the rollers, area 2 is the ball bearings that allow free movement between the rollers, area 3 is any motor drive system, and area 4 is the mounting bracket for the rollers.

[0036] In FIG. 20, area 4 is the ball bearing, area 5 is the outer ball roller cup, area 6 is the inner roller, area 7 is the bearing, and area 8 is an optional motor drive belt.

[0037] Magnetically Levitated Spindle: Magnetic bearings are currently widely used in industrial applications such as turbomolecular pumps or linear motor cars. Magnetically levitated bearings leverage technology used in other products to create a non-contact bearing system that uses permanent magnets and / or electromagnets to levitate the bobbin assembly without contact. With reference to Figures 21, 22, 23A, and 23B, magnetically levitated bearings can help eliminate the mechanical wear that contact bearings create and eliminate friction. Omnipad uses permanent magnets inside the bobbin assembly and electromagnets in the bearing block.

[0038] In Figure 23A: Region 1 is a permanent magnet embedded in the spindle and Region 2 is a permanent magnet or electromagnet. In Figure 23B, Region 1 is a magnetically polarized tread and Region 2 is a magnetically levitated bearing block.

[0039] Ball Transfer Bearing Blocks: Referring to Figures 24, 25 and 26, the ball bearings provide thrust bearing support for the bobbin assembly, allowing for low friction load transfer. The images below show the ball bearing blocks and the vertical and axial loads of the bobbin assembly. A minimum of three bearing blocks are required, but four bearing blocks are shown in the images. In these figures, area 1 is the ball transfer section configured to support axial and radial loads. The motor drive may be integrated into the ball transfer section.

[0040] Omni Wheels: Referring to FIG. 27, a standard type omni wheel (as shown) or a Mecanum type omni wheel is used to support and stabilize the spindle assembly. For full stability, more than three contact points are required; however, six contact points are depicted in the diagram. A support node requires one pair of wheels, one for the bottom and one for the top. Either or both of these wheels can be powered to control the movement of the surface.

[0041] As with other drive mechanisms, it is the surface velocity vector at the roller's contact point that determines the drive speed of the roller. Omni-directional wheels have the unique feature of only driving in the plane of the wheel perpendicular to the drive axis. All other motion passes through the roller. The drive speed at a given point is achieved by rotating and driving only as many motion vectors as the roller can handle.

[0042] Referring to Figure 27, the system is supported at 45 degrees above and below the centerline by 3-8 pairs of support wheels, which may be used in tandem to drive the tread.

[0043] Spindle: The spindle provides a rigid surface for the user to operate on as well as providing a support structure for the edge bearings. The spindle is approximately 200mm thick and has a diameter of approximately 1-2m. The top surface is designed to support the user during operation.

[0044] In actual manufacturing, the difficulty of assembling the bobbin assembly led us to look into a solution to this problem. To better understand this, it is necessary to insert a disk (spindle) into the tread (or bladder) and stretch the bladder to a very high load, eliminating wrinkles or bunching and distributing the force evenly throughout.

[0045] Solid or Segmented Spindle: Referring to FIG. 28, a segmented spindle has a solid spindle and splits it into pieces that can be assembled inside a bladder. The assembled spindle is expanded (manually or automatically) to the appropriate size and shape. In some embodiments, the solid spindle is split into smaller pieces to aid in assembling the spindle inside the bladder. Optionally, a ratchet device is used to expand the assembled spindle inside the bladder.

[0046] Alignment function

[0047] Inflatable spindle: The inflatable spindle (see area 1 in Figure 29) allows the spindle to be inserted into a small opening in the bladder during the assembly process. The spindle is then filled with a medium (gas or liquid) which makes it stiffer so that the load (bearings and user weight) can be properly supported and managed. One of the key factors of this material is its low coefficient of friction.

[0048] Drive System: Drive on an omnidirectional treadmill can be achieved through an internal or external motor. The drive system is essential to overcome the high frictional forces that the treadmill is subjected to. These motors are typically controlled by circuitry that responds to sensors that detect the movement of a user standing on the treadmill. The circuitry is configured to center the user on the treadmill as the user moves in different directions by walking or running.

[0049] Internal Drive: See Figure 30. This repeat places the drive sprockets centrally to the rollers and drives the drive belt internally. You can see the separate sections are repeated. As before, the balls are mounted in sockets which rotate freely on their own. A further variation, not shown, would connect all four roller segments together in the middle and place bearings under the ball cups as in the previous design. That variation would provide more drive to the end faces, but would result in greater vertical frictional shear forces.

[0050] See Figure 31: Area 1 is the roller surface, area 2 is the ball bearings that allow free movement between the rollers, area 3 is the motor drive system, area 4 is the roller mounting bracket. See Figure 20B: Area 4 is the ball bearings, area 5 is the outer ball roller cup, area 6 is the inner roller, area 7 is the bearings, area 8 is the motor drive belt.

[0051] Omni-directional wheels: Figures 32 and 33 show six external omni-directional wheels driving the surface. The bottom omni-directional rollers are connected to servo motors. Each omni-directional roller only drives the motion vector tangent to the contact point. Any motion transverse to the contact point passes through due to the construction of the rollers. The top omni-directional rollers typically function to fully constrain the omnipad in 3D space. Additionally, top rollers may be used to increase the contact force of the drive rollers. In theory, only three drive rollers are needed to handle all top surface motion vectors.

[0052] Drive Wheels: Referring to Figure 35, a simple drive system can drive the tread from a series of motors mounted under the bobbin assembly. See the isometric view in Figure 36. These motors are mounted on the rotating table to allow movement in any direction. The image below shows a motor system with four motors synchronized to move the tread with minimal disruption to the top user surface. In Figure 34, a simple motor and wheel drive system is depicted on a rotating table. Area 1 is the motor and encoder for the main drive wheels, area 2 is the motor and encoder for the table rotation, area 3 is the main drive wheel, used to move the tread around the spindle, area 4 is the rotating table, and area 5 is the motor base.

[0053] Ball transfer drive system: See Figures 37 and 38, the ball transfer drive system uses two motors to drive the balls supported by the underlying bearings. This allows the motors to drive the balls in any direction. This motor drive system can be mounted in the ball transfer bearing block or it can be installed in the center of the bobbin assembly as an independent motor system.

[0054] Control System: Referring to FIG. 39, the control system design controls the speed and direction of the tread surface. The control system ensures that the user has a safe and enjoyable experience when using the omnidirectional moving surface. The control system utilizes user movement feedback via a camera, force feedback via a safety harness, and feedback from the drive motor system. These different feedback systems provide validation and confirmation of the user's interaction with the Omnipad system.

[0055] Motion Feedback: Referring to FIG. 39, the Omnipad control system can use cameras or other sensors pointed at the user to determine the user's position, direction, and velocity. As the user changes some or all of the above motion characteristics, the motion feedback system can react and predictively adjust the omnipad's tread surface accordingly. The motion feedback system can also pinpoint the location of the user's body parts to provide additional feedback within the virtual environment. By knowing the user's body position and velocity, the motion feedback system calculates where the user's next step will be placed and where their center of gravity is. This feature helps to enhance the overall effectiveness of the immersive experience.

[0056] Motor Feedback: By monitoring the motor direction (forward or reverse), speed (via the motor's encoder or step), and impact angle (in terms of rotation relative to the ground), the actual position and movement of the tread can be controlled. By monitoring the motor current and encoder position, the system can monitor for system faults on the tread (i.e. the tread is not moving when it should be).

[0057] User Force Feedback: Sensors on the user harness, shoes, and / or treadmill provide the acceleration, directional, and angular forces generated by the user while manipulating the Omnipad. These accelerations and forces are processed and converted into responses by the Omnipad Tread, causing the Omnipad Tread to change direction or accelerate or decelerate while in motion.

[0058] Pivot Table System

[0059] Walking or running on a flat surface is sufficient. However, there are also inclines and slopes in the real world that can be replicated with the Omnipad system. Being able to simulate moving up, down or across hills, or even across different surface types like gravel, sand or mud, significantly improves the virtual experience.

[0060] Tilting Robot Platform: Referring to Figure 40, using a combination of linear actuators and sensors (load cells, position indicators) a motion surface can be actuated to change the tilt or pitch of the tread surface. Introducing the Tilting Robot, or Stewart Platform, the Omnipad can simulate a user going up, down or across a slope in a virtual environment.

[0061] Emulation of Changing Surfaces: Referring to FIG. 41, while the user is immersed in a virtual world with visual, auditory and motor capabilities, the omnipad control system can slightly adjust the angle and height of the tread surface to simulate various surfaces such as gravel, sand or mud.

[0062] The Omnipad control system with the immersive VR environment manipulates the user's sensory perception to give the user the sensation of walking or running on a variety of different surface types and densities, and by combining linear position indicators and load cells, the user's foot position can be calculated, allowing the precise and subtle changes required to be defined to simulate varying surface types.

[0063] Powered Omnipad Platform

[0064] Three-axis motion control using 120 degree trine and drive axes through platform center

[0065] In Figure 42, the three trines are clockwise from 0 to 120 degrees, 120 to 240 degrees, and 240 to 360 degrees. Trine 1 starts at primary drive wheel A and runs to primary drive wheel B. Trine 2 starts at primary drive wheel B and runs to primary drive wheel C. Trine 3 starts at primary drive wheel C and runs to primary drive wheel A.

[0066] The three main drive wheels (A, B, C) can theoretically drive a continuous surface by themselves. To distribute the driving force, redundant drive wheels are added. The counter drive wheels (-A, -B, -C) use the same motor input as their respective main drive wheels (A, -A), (B, -B), (C, -C), but in the opposite direction.

[0067] The inputs for driving the system are based on a Cartesian coordinate system (shown as 0, 90, 180, 270, in the center of the image). The X and Y inputs are transformed to a polar coordinate system to drive each main drive wheel using the following formulas:

[0068] Speed ​​of Motor A = COS of Polar Angle (degrees)

[0069] Motor B Speed ​​= 120 COS-Polar Angle (deg)

[0070] Speed ​​of Motor C = 60 Negative COS-Polar Angle (deg)

[0071] A continuously recycling support structure consisting of 18 "single-plane" omni-wheels evenly spaced around a circular plate.

[0072] Figure 43 shows 18 "single plane" omni wheels. Six wheels allow three wheels to be 120 degrees apart and each of the three wheels can be of opposite polarity. This defines the drive system to be multiples of six wheels: 6, 12, 18, 24, etc. For this particular diameter, 18 wheels minimizes the unsupported space between the wheels.

[0073] Note that by using a single-plane omni wheel instead of a double-plane omni wheel, it is possible to use a similar outer single-plane omni wheel to drive the inner wheels through the moving surface. It is not necessary to drive all the inner wheels. Since the moving surface can move in all directions, the undriven wheels will move as the surface is pulled across them.

[0074] For reference, Figure 44 shows a dual-planar omni wheel in both perspective and front views. Note that when the two wheels are rolled against each other, there is no consistent rolling contact due to the gap between the rollers in each plane. A dual-planar omni wheel has a set of rollers along the circumference of the wheel in two planes. Essentially, there are two sets of rollers in parallel planes around the circumference of the wheel. The problem is that the two sets of wheels are out of phase with each other to create a continuous rolling surface when rolling on a flat surface. Since only one omni wheel is driving the other, there is not much discontinuity from one roller to the next through the material of the walking surface. A single-planar omni wheel nests the second set of rollers inside the first set of rollers within the same plane. This results in very little discontinuity from roller to roller.

[0075] A spherical elastomeric balloon that is 90% or more spherical for the purposes of being stretched over a continuously recycling support structure and then "capping" to create a continuous surface.

[0076] If the balloon is not nearly spherical, it will not run smoothly. It will pull to the shortest side due to uneven tension. FIG. 45 shows a 14" diameter balloon while still on the (spherical) core mold and after removal from the core mold, also showing the through holes. The balloon preferably does not deviate from spherical by more than about 10% at any two measured diameters. If the smallest measured diameter is 10", the largest measured diameter should be 11" or less. This can also be thought of as + / - 5%. The balloon material needs to be very tough and extremely elastic. A suitable example is platinum cure silicone Shore A 03 durometer, which has a stretch to break ratio of 7. Other materials have similar properties. For example, latex, TPU, TPE, etc. can be used with appropriate manufacturing equipment. The balloon, when incorporated into an Omnipad, is understood to be the same structure as a bladder, or walking surface, etc.

[0077] Forming the balloon using multi-part mold tooling and low pressure injection molding.

[0078] FIG. 46 shows the formation of a balloon by low pressure injection molding inside a multi-part tool held together with clamps. FIG. 47 shows two parts of the mold. FIG. 48 shows the partially unmolded balloon inside the mold. More specifically, the multi-part mold tool, when assembled, defines a gap in the desired shape of a spherical balloon. There is a central spherical core with a single neck that is captured by two halves of the outer cavity, which are then assembled into the lower cavity. The result is an outer wall surface and an inner wall surface. Meanwhile, 2 part mix platinum cure silicone is injected using low pressure (e.g., 45 psi) to fill the gap and form the balloon. The outer cavity of the mold tool can then be disassembled (split) to separate it from the balloon and the spherical core. The balloon is then stretched away from the spherical core to obtain a single piece spherical balloon. There are many alternative methods for making spherical balloons, and low pressure injection molding is just one example.

[0079] The balloon is stretched over a support structure that is continuously recycled.

[0080] Figure 49 shows the manual process of stretching a balloon over a bobbin, while Figure 50 shows the bobbin with the completed balloon. Note that the balloon can be purposefully marked or colored during or after manufacture, and before or after stretching.

[0081] Sealing / capping of holes in the balloon required to stretch the balloon over the support structure to create a continuous, uninterrupted surface.

[0082] Figures 51 and 52 show an exemplary process of sealing the hole that allows the balloon to stretch over the bobbin. First, the hole is stretched closed to near zero stretch as seen in Figure 51, and then the edges of the hole are clamped to the inner structural plate. A puddle of silicone is then poured into the hole on the plate and then cured. After curing, the clamps are removed and excess material is peeled off the inner structural plate. This results in a sealed balloon wrapped over the structure of the omniwheel.

[0083] Motion tracking of "walking" objects, relocating the walking object to or near the center of the walking area.

[0084] FIG. 53 shows a schematic diagram of an exemplary omnipad planar view. The arrows in FIG. 53 represent the location and orientation of exemplary tracking cameras. Each camera can "see" a moving object on the motion surface and output position data that is used to move the circular motion surface in any direction needed to move the moving object to the center of the motion surface. One motion tracking camera operates. More cameras improve accuracy and sensitivity.

[0085] Motion control outputs (joystick, keyboard, mouse, VR / AR) from the walking surface control system to the gaming computer (PC, VR headset, etc.) synchronize the AR / VR environment motion with the walking subject's motion, i.e. simply walking on the surface drives the game movement.

[0086] Motion tracking input that causes the motion surface to return the object of motion to the center of the motion surface can also be output to a VR headset, gaming system, PC, etc. to "move" the object in a synchronized manner within the AR / VR / gaming environment. Figure 54 shows a perspective view of an omnipad including a curved video display.

[0087] Choice of active and non-active wheels.

[0088] Only three main drive wheels are required to define motion control, and only one idle wheel is required to prevent the walking surface from rotating about the vertical (Z) axis relative to the drive assembly, but four or more are preferred.

[0089] Choice of number of redundant drive wheels.

[0090] The number of redundant drive wheels can be any number, but multiples of six make the most sense. Additional intermediate wheels are also possible.

[0091] The possible range of wheel diameters (and perhaps alternative sizes of system, as well as a range of wheel size to platform size ratios).

[0092] The drive wheels roll on the outside of the walking surface, so any diameter will work. However, the goal is to keep it as small as possible. 100mm diameter wheels are readily available, but 125mm diameter wheels will also work. As the platform size increases, the wheel diameter scales as well. An exemplary maximum ratio of wheel size to platform size (diameter to diameter) is about 6:1, while the minimum is 1:1, just like a spherical walking surface. As you get closer to a sphere, everything becomes easier. However, a 20ft diameter sphere is needed to have a usable walking surface, and the goal is to keep it as small as possible.

[0093] Alternative motor / wheel ratios.

[0094] The motor to wheel ratio is reduced to a minimum number of driven wheels to a minimum number of idle wheels to avoid clocking the walking surface.

[0095] 55-60 show additional illustrations of an omni-directional treadmill according to various embodiments of the present invention. FIG. 55 shows a cross-sectional view of a bobbin showing two support omni wheels surrounded by a flexible bladder. The support omni wheels are held in place by a support structure. Each support omni wheel defines an axis of rotation that is perpendicular to the plane of the figure in the figure. The axis of rotation of each support omni wheel is also tangent to the circle defined by the arrangement of support omni wheels. Outside the bobbin are a number of drive omni wheels that contact the bladders. Each drive omni wheel is driven by a motor (not shown). Each drive omni wheel is placed on one of the support omni wheels such that the bladder is compressed between each drive omni wheel and its respective support omni wheel. In addition to the support omni wheels, an optional stabilizing omni wheel is placed outside the bobbin and also contacts the bobbin, as shown.

[0096] Figure 56 shows a top view of the bobbin of an omni-directional treadmill without a bladder. This figure shows a different perspective view of the bobbin shown in Figure 43. Both show the supporting omni wheels arranged around a circle.

[0097] 57 and 58 are plan views of the drive omni wheel and stabilizing omni wheel arranged around the bobbin according to various embodiments. FIG. 57 includes the bladder while FIG. 58 shows the internal support omni wheel without the bladder. FIG. 59 shows a perspective view of the device of FIG. 58 while FIG. 60 shows a side view. In the figure, there are six drive omni wheels, each driven by a motor. In addition, the figure shows four stabilizing omni wheels. Each stabilizing omni wheel defines an off-axis plane with respect to the center of the bobbin. The stabilizing omni wheels are paired such that each stabilizing omni wheel is located on opposite sides of its mating across the center of the bobbin and the respective planes are parallel. Each stabilizing omni wheel is positioned to contact the bladder on the opposite side of the support omni wheel. The side view shows that the omni wheels can be positioned in a plane below the central horizontal plane defined by the bobbin to support the bobbin in particular. Similarly, an omni wheel can be placed on another plane above the horizontal plane of the bobbin to hold down the bobbin. In various embodiments, the omni wheel above the plane of the bobbin is a driving omni wheel while the omni wheel below the plane of the bobbin is a stabilizing omni wheel, or vice versa, or a driving omni wheel and a stabilizing omni wheel are placed on both planes. In some embodiments, one of the stabilizing omni wheels is configured to prevent rotation of the bobbin around its vertical axis in a clockwise direction and another of the stabilizing omni wheels is configured to prevent rotation of the bobbin around its vertical axis in a counterclockwise direction.

[0098] Figures 61 and 62 show a single-planar omni-wheel in both perspective and edge-on views. As shown, a single-planar omni-wheel includes interlocking rollers or has rollers spaced apart by a distance less than the length of each roller. This prevents the rollers on one omni-wheel from locking between the rollers on the opposing omni-wheel. While this is shown for a single-planar omni-wheel, it also applies to a dual-planar omni-wheel.

Claims

1. An omnidirectional treadmill, A bobbin including a plurality of support omni-wheels, the support omni-wheels being arranged in a circle and disposed within and surrounded by a flexible bladder, the rotation axis of each of the support omni-wheels being tangent to the circumference of the circle; three drive omni-wheels arranged outside the bobbin, each of the drive omni-wheels contacting the bladder at one of the support omni-wheels such that the bladder is compressed between each of the drive omni-wheels and a respective support omni-wheel; An omnidirectional treadmill equipped with

2. 10. The treadmill of claim 1, wherein the flexible bladder comprises a dynamic material configured to change shape in response to an electric or magnetic field.

3. 3. The treadmill of claim 1 or 2, wherein the flexible bladder comprises a ferromagnetic material.

4. 3. The treadmill of claim 1 or 2, wherein the flexible bladder is configured to be dynamically more flexible in the circle of the supporting omni-wheel relative to the center of the circle.

5. 3. A treadmill according to claim 1 or 2, wherein the support omni-wheel and / or the drive omni-wheel are uniplanar omni-wheels.

6. 3. The treadmill of claim 1, wherein at least three of the drive omni-wheels are configured to support the bobbin.

7. 3. A treadmill according to claim 1 or 2, comprising six or nine driven omni-wheels.

8. 3. The treadmill of claim 1, wherein the bobbin includes a magnet configured to prevent the circle of the support omni-wheel from rotating about a center of the bobbin relative to the drive omni-wheel.

9. 3. The treadmill of claim 1 or 2, further comprising two or four stabilizing omni-wheels, each of the stabilizing omni-wheels positioned adjacent to a respective supporting omni-wheel.

10. 3. The treadmill of claim 1 or 2, further comprising two or four stabilizing omni-wheels configured to prevent rotation of the bobbin about a vertical axis defined through the center of the bobbin.

11. 3. The treadmill of claim 1 or 2, wherein any of the omni-wheels includes interlocking rollers or has rollers spaced apart by a distance less than the length of each roller.

12. 3. The treadmill of claim 1, wherein three of the drive omni-wheels are positioned below a horizontal surface of the bobbin and configured to support the bobbin.

13. 3. The treadmill of claim 1, wherein the three drive omni-wheels are arranged on a horizontal plane defined by the bobbin and configured to press down on the bobbin.

14. 3. The treadmill of claim 1 or 2, further comprising three, four, or six omni-wheels, each of the omni-wheels aligned with a respective supporting omni-wheel and configured to support the bobbin.

15. 3. The treadmill of claim 1 or 2, wherein each of the drive omni-wheels includes 12 rollers.

16. 10. The treadmill of claim 9, wherein one of the stabilizing omni-wheels is configured to prevent rotation of the bobbin about its vertical axis in a clockwise direction and another of the stabilizing omni-wheels is configured to prevent rotation of the bobbin about its vertical axis in a counterclockwise direction.

17. 3. The treadmill of claim 1, wherein three of the drive omni wheels are arranged in a first plane and three of the drive omni wheels are arranged in a second plane.

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