WO2019104177A1

WO2019104177A1 - Magnetic levitation with device and system

Info

Publication number: WO2019104177A1
Application number: PCT/US2018/062260
Authority: WO
Inventors: Simon Morris
Original assignee: Flyte Llc
Priority date: 2017-11-21
Filing date: 2018-11-21
Publication date: 2019-05-31

Abstract

A magnetic levitation device and system is disclosed. The system includes a printed circuit board (PCB). The printed circuit board (PCB) is embedded with magnets, electromagnets, an accelerometer, position sensors and a microprocessor. The magnets are configured to generate a static magnetic field and providing a position-dependent potential energy of an interaction with a magnetic element. The electromagnets are configured to generate a control magnetic field with the accelerometer upon the passage of an electrical current through the electromagnets and the position sensors are configured to generate a feedback signal indicative of a position of the magnetic element. Further a controller is connected to receive the feedback signal and to control the electrical current in the electromagnets to prevent the magnetic element from leaving a vicinity of the equilibrium position.

Description

MAGNETIC LEVITATION WITH DEVICE AND SYSTEM

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority on ET.S. Provisional Patent Application No. 62/589,392, entitled“MAGNETIC LEVITATION DEVICE AND SYSTEM ", filed on November 21, 2017, which is incorporated by reference herein in its entirety and for all purposes.

TECHNICAL FIELD

This invention generally relates to electromagnetic levitation technology and more specifically to electromagnetic levitation or suspending systems and devices.

BACKGROUND Many people have always had a fascination with magnetic levitated objects or suspended objects. Magnetic levitation, maglev, or magnetic suspension is a method by which an object is suspended with no support other than magnetic fields. Magnetic force is used to counteract the effects of the gravitational acceleration and any other acceleration.

The two primary issues involved in magnetic levitation are lifting forces: providing an upward force sufficient to counteract gravity, and stability: ensuring that the system does not spontaneously slide or flip into a configuration where the lift is neutralized.

Magnetic levitation devices selectively oscillate or modulate a levitating force to float or levitate a displayed object or to animate an object and have been available for many years. Manipulating magnetic fields and controlling their forces to levitate an object is disclosed in many references. Such references include mechanisms for magnetically levitating an object, as well as controlling the spatial position of such a magnetically levitated object. Magnetic levitation devices typically use a horizontal support stand to provide an overhead electromagnet, and an obj ect with a permanent magnet or at least a ferrous obj ect embedded within it or on an outer surface is then positioned under the electromagnet. Some of the references of magnetic levitation systems are shown in U.S. Pat. Nos. 6,595,041, 6,035,703, 5,980,193, 5,319,670, 5,168,183, 4,585,282, and 4,191,951, all of which are incorporated by reference.

A magnetically levitated object can be suspended above a base by magnetic fields. An electromagnetic force is used to counteract the effects of gravity. The forces acting on an object in any combination of gravitational, electrostatic, and magnetostatic fields will make the object's position unstable. The reason a permanent magnet suspended above another magnet is unstable is because the levitated magnet will easily overturn, and the force will become attractive (Eamshaw's Theorem). The prior art includes mechanisms for magnetically levitating an object, as well as controlling the spatial position of such a magnetically levitated object.

The application provides a magnetic levitation device and system that can determine the polarity of the magnetic field and position, detecting motion and orientation in order to solve the above problems. SUMMARY OF THE INVENTION

This application provides a magnetic levitation device and system with an integrated position sensor to sense the distance between the levitated object and the electromagnet. More specifically, the invention provides an electromagnetic levitation device and system having at least one hall sensor for detection of levitated object position, which provides feedback in terms of output voltage (digital or analog) respective to its position.

In one aspect of the present invention provides an electromagnetic levitation system, comprising a printed circuit board (PCB). The printed circuit board (PCB) is embedded with plurality of magnets, plurality of electromagnets, an accelerometer, plurality of position sensors and a microprocessor. The plurality of magnets are generally paramagnets which are arranged on a substantially common plane having a longitudinal axis; and are adapted to generate the static magnetic field at an equilibrium position spaced apart from the substantially common plane. The magnets are configured to generate a static magnetic field and providing a position- dependent potential energy of an interaction with a magnetic element.

The electromagnet comprises one or more coils, that are operatively connected to the accelerometer, spaced along an axis parallel to an unstable axis. The electromagnets are configured to generate a control magnetic field with the accelerometer upon the passage of an electrical current through the electromagnets and the position sensors are configured to generate a feedback signal indicative of a position of the magnetic element.

Further a controller is connected to receive the feedback signal and to control the electrical current in the electromagnets to prevent the magnetic element from leaving a vicinity of the equilibrium position.

In another aspect of the present invention provides an electromagnetic levitation device. the device comprises at least two magnets arranged to generate a static magnetic field providing a position-dependent potential energy of interaction with a magnetic element and an accelerometer. In certain aspects of the present invention, the device includes at least one electromagnet together with an accelerometer.

Further in certain aspects, the device includes at least three electromagnets arranged in a pattern together with an accelerometer. The device may also include position sensors for generating a feedback signal indicative of the position of the magnetic element on the unstable axis, an electromagnet configured to generate a control magnetic field upon the passage of an electrical current through the electromagnet, and the control magnetic field having a gradient with respect to displacements along the unstable axis at the equilibrium position. A controller may be connected to receive the feedback signal and to control the electrical current in the electromagnet to prevent the magnetic element from leaving a vicinity of the equilibrium position. In some examples, the electromagnet has two coils spaced along an axis parallel to the unstable axis, which can be operatively connected to the accelerometer(s).

In another aspect of the present invention, the position sensors (e.g., Hall Effect Sensor) or accelerometers can be integrated in any suitable device. The accelerometers may be one- axis accelerometers as well as two-axis, three-axis or more accelerometers, for force, velocity, and position determination. While there are many kinds of small accelerometers and other small accelerometers that would work, piezoelectric accelerometers may be used. Piezoelectric accelerometers acceleration is measured by the change in capacitance due to a moving plate attached to the proof mass. Piezoelectric accelerometers are more popular. The electromagnet comprises one, two or more coils, some or all of which are operatively connected to an accelerometer, spaced along an axis parallel to the unstable axis. For example, the electromagnet may comprise four coils spaced along an axis parallel to the unstable axis - upon the passage of the electrical current through the four coils each of the four coils has a magnetic polarity opposite to the magnetic polarity of adjacent ones in the four-coil pattern. A microprocessor is operatively connected to the accelerometer(s) drives the current to the coils based on the position of the marker. When the marker is shifting, the coils will adjust to maintain the markers position.

When the position and trajectory of the magnetic element is measured and conveyed to a control system, the field of the electromagnets can be continuously adjusted via feedback control systems to keep the levitated magnetic element in the desired position. A feedback control system to levitate a magnet is commercially available from many sources. A Hall Effect sensor tracks the position of the levitating magnet. The Hall effect sensor produces an electrical signal based on the strength of the perpendicular component of the local magnetic field. As the distance between the sensor and the magnet increases, the signal produced by the sensor becomes weaker. The signal from the sensor controls the duty cycle of the analog or digital signal, which in turn controls the current supplied to the electromagnet, which is operatively connected to the accelerometer(s). To calculate the forces when dealing with non-uniform magnetic fields and permanent magnets, a Computer-Aided-Design (CAD) system such as the Maxwell 3D can be used to solve 3D magnetostatic problems.

In one example, the device for levitating a magnetic element has at least three magnets defining a substantially common plane having a longitudinal axis and a latitudinal axis and adapted to generate a static magnetic field at an equilibrium position spaced apart from the substantially common plane, a position sensor adapted to generate a feedback signal indicative of the position of the magnetic element relative to the equilibrium position; an electromagnet adapted to generate a control magnetic field to control motion of the magnetic element relative to the equilibrium position; one or more accelerometers operatively connected to the electromagnet (e.g., through a microprocessor), and a controller connected to the position sensor and the electromagnet and adapted to receive the feedback signal from the position sensor.

In certain examples, accelerometers can measure acceleration on one, two, or three axes. 3-axis units are becoming more common as the cost of development for them decreases. Generally, accelerometers contain capacitive plates internally. Some of these plates are fixed, while others are attached to miniscule springs that move internally as acceleration forces act upon the sensor. As these plates move in relation to each other, the capacitance between them changes. From these changes in capacitance, the acceleration can be determined. Other accelerometers can be centered around piezoelectric materials. These tiny crystal structures output electrical charge when placed under mechanical stress (e.g. acceleration).

In another aspect of the invention provides device for levitating a magnetic element. The device comprises (a) a means for generating a static magnetic field providing a position- dependent potential energy of interaction with a magnetic element, and (b) an accelerometer operatively connected to the means, e.g., through a microprocessor. The static magnetic field providing an equilibrium position in which the potential energy decreases for displacements of the magnetic element away from the equilibrium position along an unstable axis and increases for displacements of the magnetic element away from the equilibrium position in any direction perpendicular to the unstable axis. The accelerometer senses and provides data regarding the position and orientation of the device and transmits to a microprocessor, which provides feedback signal indicative of the position of the magnetic element on the unstable axis and control the means for directing the magnetic element to the equilibrium position.

Other features and advantages of the present invention will become apparent from following specification taken in conjunction with the enclosed drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

This application will be described with reference to the following drawings. The drawings and the associated descriptions are provided to illustrate embodiments of the invention and not to limit the scope of the invention.

FIG. l is a perspective view of an electromagnetic levitation system and device in accordance with an embodiment of the present invention; and

FIG.2 shows a printed circuit board (PCB) of the electromagnetic levitation system and device in accordance with an embodiment of the present invention;

FIG.3 is an electromagnetic levitation device in accordance with another embodiment of the present invention;

FIG.4 is a combination block and schematic diagram of the circuitry utilized in arrangements of the electromagnetic levitation system in accordance with an embodiment of the present invention.

FIG.5 is another block and schematic diagram of the circuitry utilized in arrangements of the electromagnetic levitation system in accordance with an embodiment of the present invention.

FIG. 6 is an exemplary magnetic levitation timing device on a vertical surface (e.g., a wall). DETAILED DESCRIPTION OF THE INVENTION

The present invention now will be described more fully hereinafter with reference to the accompanying drawings. While the following description details the preferred embodiments of the present invention is not limited in its application to the details of construction and arrangement of the parts illustrated in the accompanying drawings.

A typical electromagnetic configuration or levitation unit that can be used with certain embodiments is known in the art. The electromagnet is powered or driven with a control signal that is maintained via a stable feedback loop to provide a suspending magnetic field or levitating force to float the object at a fixed distance and position relative to the electromagnet. The feedback loop may include a position sensor (such as a Hall effect sensor) to sense the distance between the levitated object and either the electromagnet itself or a separate magnet (e.g., a magnet placed at the bottom or base of the levitated object).

Referring to FIG.l, in one embodiment, this application provides a magnetic levitation system 10.

In one embodiment as shown in FIGs. 1 and 2 is a magnetic levitation system 10 according to the invention. The system 10 includes a plurality of magnets 14, a plurality of electromagnets 16, a plurality of position sensors 18 and microprocessor 24 are embedded in a printed circuit board (PCB) 20. A connector 12 is configured on the printed circuit board (PCB) 20 to connect an external power source. The PCB 20 may include a plurality of components required to allow the device to operate as disclosed herein. The PCB may include processing circuitry (illustratively shown in FIG. 3) including a memory and a processor. The memory may be in communication with the processor and having instructions that, when executed by the processor, configure the processor to activate the magnet array, receive information from other system components, or perform other functions. The PCB 20 may include a BLEIETOOTH® chip, infrared wireless components, ultra wideband components, induction wireless components, or other wireless communication components for the short-range wireless communication between the base and the object and/or the input signals.

The plurality of magnets 14 are generally paramagnets which are arranged on the printed circuit board (PCB) 20 on a substantially common plane having a longitudinal axis; and are adapted to generate the static magnetic field at an equilibrium position spaced apart from the substantially common plane. The magnets 14 are configured to generate a static magnetic field and providing a position-dependent potential energy of an interaction with a magnetic element. The strength of the magnet 14 is chosen to balance the suspended object using electromagnetic force, based on the desired distance and weight of the suspended object; or the distance is chosen based on the already specified permanent magnet strength.

The electromagnets 16 comprise one or more coils, that are operatively connected to an accelerometer 22, spaced along an axis parallel to an unstable axis. The electromagnets 16 are configured to generate a control magnetic field with the accelerometer upon the passage of an electrical current through the electromagnets 16 and the position sensors 18 are configured to generate a feedback signal indicative of a position of the magnetic element.

The accelerometers 22 are operatively connected to the electro-magnetic coils 16 to drive the electromagnets 16 independently depending on its orientation. In one example, the accelerometers 22 in conjunction with positional sensors 18 can sense its position and orientation of the device. Depending on the way it is held, it can drive the electromagnetic coils 16 independently in the configuration to optimize the position of a marker, e.g., it can keep the marker stable. For example, in a system 10 having four electromagnetic coils, if the base is upright, it will drive more power to and adapt the polarity of coils 1 and 4. If the base is flat, it will drive more power to coils 1 and 4 and 2 and 3, etc. Not only connect digital input devices such as accelerometers 22, but other digitally controlled sensors, such as gyroscopes may be included with the device. Such digital sensors would also help stabilize the electromagnetic field. The accelerometer 22 and position sensors (Hall Effect Sensor) 18 could sense any disturbances caused by shock or vibration and compensate the electromagnetic coils 16 accordingly, thus preventing the suspended/levitated object from falling down. The magnetic element is steadied notwithstanding movement of the base. Accordingly, specific embodiments provide a digitally controlled magnetic levitation environment, as opposed to an analog setup, through the use of additional of the accelerometer(s). A more stable levitated element is possible, which can be maintained in various orientations.

Further a controller may be connected to receive the feedback signal and to control the electrical current in the electromagnet to prevent the magnetic element from leaving a vicinity of the equilibrium position. In some examples, the electromagnet 16 has two coils spaced along an axis parallel to the unstable axis, which can be operatively connected to the accelerometer(s) 22.

In one embodiment, the base may be in wired communication with an input device. The input device may accept signals such as temperature, proximity, barometric, gestural sensors can be used as input devices. Further the input device may be an accelerometer.

The input device may be a phone, computer, tablet, or other handheld unit. If the user input device is a cellular telephone, for example, the cellular telephone may be compatible for use with an external RFID reader that can communicate with RFID tags in the base, object, and/or other items, such as golf clubs. Alternatively, the base and/or object may include wireless communication component (transmitters and receivers) other than RFID devices, such as a BLUETOOTH® chip or other suitable alternatives. Thus, the user may be able to automatically activate, deactivate, and control the object about the base 12 through his or her cellular phone without the need for additional equipment or system components.

A controller adjusts current in coils 16 to maintain levitated magnetic element at equilibrium position. The controller may comprise any suitable control technology including a suitably programmed data processor such as a computer, programmable controller, or digital signal processor, or a suitable analog or digital feedback control circuit. The equilibrium position can be a position such that the static magnetic field of magnets 14 provides enough force to counteract the force of gravity on magnetic element at equilibrium position in the absence of current flowing in coils 16. In such embodiments it is only necessary to cause current to flow in coils 16 when magnetic element has moved or is moving away from equilibrium position. This makes it possible to minimize the electrical power expenditure required to stabilize magnetic element at equilibrium position through feedback signal received from the controller.

The controller is to enable suspension of the object and controlling the suspension. However, the position of the suspended object and the strength of the magnet 14 changes from use and applications in different types of object, the controller must check position and strength of the magnets for suspension.

In one embodiment, the position sensors (e.g., Hall Effect Sensors) 18 or accelerometers 22 can be integrated in any suitable device. The accelerometers may be one-axis accelerometers as well as two-axis, three-axis or more accelerometers, for force, velocity, and position determination. While there are many kinds of small accelerometers and other small accelerometers that would work, piezoelectric accelerometers may be used. Piezoelectric accelerometers acceleration is measured by the change in capacitance due to a moving plate attached to the proof mass.

In another embodiment as shown in FIG. 3, an electromagnetic levitation device 10, the magnets 14 are arranged on a substantially common plane having a longitudinal axis and adapted to generate the static magnetic field at an equilibrium position spaced apart from the substantially common plane and the electromagnets 16 comprises one or more coils. The electromagnetic coils 16 generate a variable magnetic field under the control of the accelerometer 22. When magnetic element 40 moves away from its levitated equilibrium position, the accelerometer 22 adjusts flow of electrical current in the electromagnetic coils

16 to generate a control magnetic field that results in a force being applied to a magnetic element 40. The force pushes magnetic element in a selected direction along the unstable axis. The variable control magnetic field generated by the passage of electrical current in the electromagnetic coils stabilizes levitated magnetic element 40. This creates a stabilizing magnetic field which applies force to urge magnetic element 40 in one direction along the unstable axis in which current flows in each of coils can be reversed. The control magnetic field having a gradient with respect to displacements along the unstable axis at the equilibrium position. The magnitude of the stabilizing force applied to magnetic element

40 is proportional to the magnitude of the gradient of the magnetic field at the position of magnetic element 40.

FIG. 4 and FIG. 5 principally represent the power supply circuitry for arrangements of the system 10 of the present invention. In the example in FIG. 4, three electromagnets are shown and may be more in other examples. Further in FIG. 5, there are four electromagnets

(represented by“4X”) that the independently controllable. The circuitry is operably coupled to the electromagnet 16 to deliver a signal to the system 10. As shown in the FIG. 3, position sensors (Hall Effect sensors) 18 track the position of a magnetic element 40 and produces an electrical signal based on the strength of the magnetic field. The signal from the sensor controls the current supplied to the electromagnet 16, which is operatively connected to the accelerometer(s) 22. Based on that a preference voltage is supplied by amplifying through a noninverting power amplifier.

As can be seen from FIG. 5, every coil carries or can carry a current (the amount depends on the inductance of the coil and the pulse-width modulation frequency). Each electromagnetic current may not carry current. This allows each of the electromagnets to be independently controlled by the microprocessor or ultimately the input signal. This allows magnetic levitations to be applied on moving platforms.

The magnetic levitation system disclosed in this application may be configured with traditional magnetic levitation systems 100 to provide digital control over the magnetic forces. FIG. 6 shows a magnetic levitation device having features of the invention. Such traditional devices for levitating an object 110 above a surface having a power source typically have a base 120 and a magnet array proximate the base (not shown), the magnet array having a plurality of electromagnets and a permanent magnet. The magnet array is in communication with the power source. The magnets and sensors may be digitally controlled by an input signal, e.g., an accelerometer. Other systems are disclosed in US Patent Nos. 7348691 and 8,258,663.

Another embodiment includes a method for stabilizing a magnetic levitation device (e.g., those found the art) comprising using an accelerometer operatively connected to the electromagnets of the device and using a microcontroller operatively connected to the accelerometer to adjust the current to the electromagnets. Thereby, this improves the stability of the levitated object.

For example, the magnetic levitation device 10, may include the system described here, may be place on a wall W or other type of vertical/non-flat surface. In this arrangement, the device 110 can be operatively connected to a power outlet P by for example a cord 111. The marker 120 is suspended away from the device 110 and may move or rotate. Such applications include those shown in WO2018094401.

The foregoing description of embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiments were chosen and described in order to explain the principals of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated.

Claims

1. An electromagnetic levitation system, comprising: a printed circuit board (PCB) configured with a microprocessor, the printed circuit board (PCB) operatively connected to a plurality of magnets, a plurality of electromagnets, an accelerometer, and a plurality of position sensors, and a power source, wherein the plurality of magnets are configured to generate a static magnetic field and providing a position-dependent potential energy of an interaction with a magnetic element; the plurality of electromagnets configured to generate a control magnetic field with the accelerometer upon the passage of an electrical current through the electromagnets; the plurality of position sensors configured to generate a feedback signal indicative of a position of the magnetic element; and a controller is configured to receive the feedback signal and to control the electrical current in the electromagnets to prevent the magnetic element from leaving a vicinity of an equilibrium position.

2. The system of claim 1, wherein three electromagnets are each independently controllable by the microprocessor.

3. The system of claim 1, wherein the magnets are arranged on a substantially common plane having a longitudinal axis; and are adapted to generate the static magnetic field at an equilibrium position spaced apart from the substantially common plane.

4. The system of claim 1, wherein the electromagnet comprises one or more electromagnetic coils which are operatively connected to the accelerometer, spaced along an axis parallel to the unstable axis.

5. The system of claim 1, further comprising an object, wherein the object comprising a body with a magnetic element.

6. The system of the claim 1, wherein the positional sensors are Hall Effect sensors that tracks the position of the magnetic element.

7. The system of claim 1, wherein the accelerometers are of one-axis accelerometers.

8. The system of claim 1, wherein the accelerometers are of two-axis accelerometers.

9. The system of claim 1, wherein the accelerometers are of three-axis or more accelerometers.

10. The system of claim 1, wherein the accelerometers are Piezoelectric accelerometers.

11. The system of claim 1, where the control magnetic field having a gradient with respect to displacements along the unstable axis at the equilibrium position.

12. The system of claim 1, wherein the controller is configured to receive the feedback signal in term of the position of the magnetic element.

13. The system of the claim 1, wherein the microprocessor is operatively connected to the accelerometers, the accelerometers drive the current to the electromagnetic coils based on the position of a marker.

14. An electromagnetic levitation device, comprising: plurality of magnets; the magnets are arranged on a substantially common plane having a longitudinal axis; and adapted to generate the static magnetic field at an equilibrium position spaced apart from the substantially common plane, and the magnets are configured to generate a static magnetic field and providing a position-dependent potential energy of an interaction with a magnetic element; an accelerometer is configured for force, velocity, and position determination of the magnet; a plurality of electromagnets configured to generate a control magnetic field with the accelerometer upon the passage of an electrical current through the electromagnets; a plurality of position sensors configured to generate a feedback signal indicative of a position of the magnetic element; and a plurality of position sensors configured to generate a feedback signal indicative of a position of the magnetic element, wherein, a controller is configured to receive the feedback signal and to control the electrical current in the electromagnets to prevent the magnetic element from leaving a vicinity of an equilibrium position.

15. The device of claim 14, wherein the magnets comprises permanent magnets.

16. The device of claim 14, wherein the electromagnet comprises one or more electromagnetic coils which are operatively connected to the accelerometer, spaced along an axis parallel to the unstable axis.

17. The device of the claim 14, wherein the positional sensors are Hall Effect sensors that track the position of the magnetic element.

18. The device of claim 14, wherein the controller is configured to receive the feedback signal in term of the position of the magnetic element.

19. The device of the claim 14, wherein a microprocessor is operatively connected to the accelerometers, the accelerometers drive the current to the electromagnetic coils based on the position of a marker.

20. A method for stabilizing a magnetic levitation device comprising using an accelerometer operatively connected to electromagnets of the device and using a microcontroller operatively connected to the accelerometer to adjust the current to the electromagnets.