FORM 2
THE PATENTS ACT, 1970
(39 of 1970
&
THE PATENT RULES, 2005
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION: Magnetically Suspended CMG Based Auto Balancing System For Two Wheeler
Applicant Name: Liger Mobility Private Limited
Nationality: Indian
Address: A9 Pearl Heaven, Chapel Road Bandra West, Mumbai, Maharashtra, India 400050
Inventor Name: ASHUTOSH UPADHYAY
Nationality: Indian
Address: A1902 Shimmering Heights, Near Powai Vihar Complex, Opposite Custom's
Colony Powai, Mumbai, Maharashtra, India 400076
Inventor Name: VIKAS PODDAR
Nationality: Indian
Address: A9 Pearl Heaven, Chapel Road Bandra West, Mumbai, Maharashtra, India 400050
PREAMBLE OF THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is
to be performed

TECHNICAL FIELD
The present subject matter in general, is designed to solve the limitations in two wheelers and more specifically, bring the balancing solution suitable for compact applications in two wheelers with the help of magnetic bearing in CMG.
BACKGROUND OF THE INVENTION
Two wheelers are widely used for their small size, fuel economy and ease of use. Two-wheeled vehicles have many advantages over other concepts such as smaller size, more efficient, and more maneuverable. These advantages came from the lack of stability and safety. The two wheeler has become a research hotspot recently, and one of the most challenging problems for its realization is the method to keep the two wheeler balanced. To improve the stability and safety of a two-wheeled vehicle, the Control Moment Gyroscope auto balancing is considered. The problem of auto balancing an inherently unstable body is a classical control theory problem. The idea of using the gyroscope effect for auto-balancing is part of a much broader effort to implement with this invention. As the vehicle leans from its upright position, we expect to generate sufficient gyroscopic reaction moments to bring the vehicle back and auto balance it.
The control moment gyroscope (CMG) is one of the angular momentum exchange devices which is the application of this research that can produce large output torque on the body. It consists of the motor-driven rotor and gimbal. The spin axis of the flywheel can vary about a perpendicular axis to its spin axis (the gimbal axis). Complex dynamic derivations are used to find a relationship between the torque input to the gimbal axis and a desired output torque on the body. The rate of change of angular momentum between the CMG and the body is dependent on the spin velocity(gimbal velocity). However, two-wheeler riders can greatly benefit from the comfort and safety provided by a CMG based Auto balancing device.
The size of the CMG is inversely proportional to the SPIN RPM of the CMG. Contact bearings are not capable of running over 10,000 – 20,000 RPM. Moreover the friction losses in the bearings increase linearly with the RPM. In addition, the air drag losses increase in proportion to the cube of RPM. The air drag losses can not be reduced by

creating vacuum as lubrication for contact bearings does not work well in vacuum. Due to these losses, the CMG cannot be left spinning all the time. This results in the need to Spin up and shut down the CMG before and after use. The user needs to wait for the Spin up before the CMG is usable. Also, not all energy from the spin down can be recovered.
One example of a self balancing two wheeler having a stopper device may be found in Indian application number 201821002735 providing a system, method and a device for balancing a vehicle. In one embodiment the system comprises of a control moment gyroscope. In another embodiment two or more control moment gyroscopes may be provided. Further, in an embodiment a mechanism to provide stopping of a precession shaft that links the control moment gyroscope to the vehicle is provided. Furthermore, a user operable switch may be provided in an embodiment to stop the precession shaft of the control moment gyroscope.
A system and method for preserving power of a flywheel and enabling a two wheeler, especially the ones having self balancing capabilities is needed.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides a magnetic bearing system for a two wheeler having self balancing features using a control moment gyroscope(CMG), comprising a flywheel attitude sensor of a flywheel of said CMG, configured to sense the attitude of the flywheel in reference to a housing of the CMG; a magnetic bearing comprising a magnetic flux inducing coil, configured to alter the attitude of the flywheel; and a bearing control unit, configured to receive the attitude from said flywheel attitude sensor, and calculate one or more features of the magnetic flux needed based on said attitude of the flywheel.
In an embodiment the flywheel is of a material that is maneuverable based on a magnetic flux. In another embodiment, the precision action of a control moment gyroscope is stoppable by using a stopper device while the flywheel continues in spinning condition.

In yet another embodiment, the bearing control unit, is configured to receive the attitude from said flywheel attitude sensor, receive the status of the stopper device, calculate one or more feature of the magnetic flux needed based on said attitude of the flywheel and the status of the stopper device.
Further, in one embodiment, the bearing control unit, is configured to receive the attitude from said flywheel attitude sensor, receive the status of stopper device being inactive, calculate precision velocity, and calculate one or more feature of the magnetic flux needed based on said attitude of the flywheel and said precision velocity.
In one embodiment, the system comprises an auxiliary bearing configured to provide support to a shaft of the flywheel during magnetic bearing failure, and for slowing of said flywheel. Further, in another embodiment, the system comprises a flywheel spin motor in CMG, for providing a spin torque.
In one embodiment, the bearing control unit is configured to provide a reverse spin signal to the flywheel spin motor for quick slowing down of said flywheel.
In one embodiment, the bearing control unit is configured to calculate a tolerance index indicative of a level of accuracy needed for maneuvering of said flywheel. In yet another embodiment, the bearing control unit is configured to maintain a higher tolerance index when said stopper device is inactive as compared to when the said stopper device is active.
In one of the embodiments, a method maneuvering a flywheel of a control moment gyroscope(CMG), in a magnetic bearing system for a two wheeler having self balancing features using a control moment gyroscope(CMG), comprising the steps of:
A. starting the spinning of the flywheel using a rotating means;
B. intermittently receiving the attitude of the flywheel in reference to a housing of the
CMG;

C. levitating the flywheel by intermittently altering a current in a magnetic flux inducing coil, configured to alter the attitude of the flywheel within a prescribed threshold limit for contactless rotation.
The embodiment further comprises the steps of intermittently checking and maintaining the RPM of the said flywheel; and intermittently checking the status of a stopper device configured to stop the precision shaft of the CMG while flywheel continues in spinning condition.
In yet another embodiment, the method comprises the steps of receiving the attitude from said flywheel attitude sensor, receiving the status of the stopper device being inactive, calculating a precision velocity, and calculating one or more features of the magnetic flux needed based on said attitude of the flywheel and said precision velocity. It further comprises the steps of receiving the attitude from said flywheel attitude sensor, receiving the status of stopper device being inactive, calculating the precision velocity, and calculating one or more feature of the magnetic flux needed based on said attitude of the flywheel and said precision velocity.
In one of the embodiments, the method comprises the steps of enabling supporting or slowing down of a flywheel using an auxiliary bearing. It further comprises the steps of signaling a flywheel spin motor in CMG, for providing a spin torque.
In yet another embodiment, the method comprises the steps of sending a reverse spin signal to the flywheel spin motor for quick slowing down of said flywheel. The embodiment further comprises the steps of calculating a tolerance index indicative of a level of accuracy needed for maneuvering of said flywheel.
In an embodiment, the method comprises the steps of maintaining a higher tolerance index when said stopper device is inactive as compared to when the said stopper device is active.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
A clear understanding of the key features of the invention summarized below may be had by reference to the appended drawings, which illustrate the development of

Magnetically suspended CMG based auto balancing system for two wheeler, although it will be understood that such drawings depict preferred embodiments herein and, therefore, are not to be considered as limiting its scope with regard to other embodiments which the invention is capable of contemplating. Accordingly:
Figure 1 illustrates the flow of working principle of magnetically suspended CMG for auto balancing of two wheeler, as per an embodiment herein.
Figure 2 illustrates the assembly of the CMG with flywheel, as per an embodiment herein.
Figure 3 illustrates a method maneuvering a flywheel of a control moment gyroscope(CMG), in a magnetic bearing system for a two wheeler having self balancing features using a control moment gyroscope(CMG).
Figure 4 illustrates the assembly of the two CMG’s with opposite spin and precision on the vehicle as per an embodiment herein.
DETAILED DESCRIPTION OF THE INVENTION
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well as the singular forms, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof.
Unless, otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one having ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a

meaning that is consistent with their meaning in the context of the relevant art and the present disclosure and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
In describing the invention, it will be understood that a number of techniques and steps are disclosed. Each of these has individual benefits and each can also be used in conjunction with one or more, or in some cases all, of the other disclosed techniques. Accordingly, for the sake of clarity, this description will refrain from repeating every possible combination of the individual steps in an unnecessary fashion.
The present invention discloses a magnetically suspended CMG based auto balancing device for two wheelers with the help of using magnetic bearings.
This invention also aims to solve the limitations and provide solutions suitable for compact applications and extremely energy efficient in two wheelers with the help of magnetic bearings in CMG.
The present invention consists of a. CMGs (Control Moment Gyroscope ), that may be one or two in number, b. stopper device (for Precision) c. Flywheels for spinning on the magnetic bearings. The CMG consists of a spinning rotor with a large, constant angular momentum, whose angular momentum vector direction can be changed for a two wheeler by rotating the spinning rotor. The spinning rotor, which is on a gimbal, applies a torque to the gimbal to produce a precessional, gyroscopic reaction torque orthogonal to both the rotor spin and gimbal axes. A CMG amplifies torque because a small gimbal torque input produces a large control torque to the two wheeler.
Figure 1 of the present embodiment explains the flow of working principle of magnetically suspended CMG for auto balancing of two wheeler. CMG(Control moment gyroscope) started rotating (101). Here checking of proper positioning of flywheel and shaft position is done via sensor (102). Start the motor to spin the suspended flywheel (103). Now levitate the flywheel or shaft and ensure their attitude is within the threshold limit for contactless rotation (104). At this stage alter the current in coils of magnetic bearing to generate the required amount of magnetic fields or magnetic strength for controlling flywheel or shaft. The flywheel mounted over the

shaft is not in contact with any surfaces.This ensures there are no contact friction losses. Check flywheel/ shaft attitude (104). Monitor working of magnetic bearing(105). The bearing needs to keep the flywheel position stable along all axes giving it no degree of freedom apart from rotation about spin axis. Now stop the motor from spinning and land the flywheel or shaft on auxiliary contact bearings. Now let the flywheel spin down to 0 RPM. Optionally use the motor to provide further de-acceleration to the flywheel rotation. Maintain target RPM for flywheel for desired result (106).
Figure 2 of the present embodiment explains, assembly of CMG with a flywheel. Here one shaft (201) is present on which the flywheel (202) is suspended. From one end of the shaft, the Spinning Motor (203) is connected. Near to the spinning Motor, one Auxiliary bearing (204) is present and another Auxiliary bearing (205) is present on the opposite end. Two Active magnetic bearings are positioned over the Auxiliary bearing. Here two types of magnetic bearing are used. One is Auxiliary bearing and other one is magnetic bearing. Now magnetic bearings may be of two types 1. Active magnetic bearing (206) and 2. Passive magnetic bearing. The active magnetic bearing needs to keep the flywheel position stable along all axes giving it no degree of freedom apart from rotation about spin axis. This ensures there are no contact friction losses. Active magnetic bearing is a magnetic coil which generates magnetic fields when current is passed through them. Active magnetic bearing is now positioned over the shaft. Here the flywheel/shaft are magnetized so that they can be moved by repelling/attracting magnetic fields from the magnetic bearing coils. The flywheel attitude sensing and corrective adjustment of flywheel position (by varying the current flow in active magnetic bearing coils) is done periodically by the bearing control unit. Here flywheel attitude means position of the flywheel in 6 axes (3 degree of rotation and 3 degree of movement).
In one embodiment herein, a magnetic bearing system for a two wheeler having self balancing features using a control moment gyroscope(CMG) may comprise of a flywheel attitude sensor of a flywheel of said CMG, configured to sense the attitude of the flywheel in reference to a housing of the CMG. Further, a magnetic bearing

comprising a magnetic flux inducing coil, configured to alter the attitude of the flywheel may be provided. The magnetic flux inducing coil may be wound on a magnetic material configured to further provide magnetic flux in addition to that provided by permanent magnets. In one embodiment flux inducing coils may cause magnetism to begin with where no magnetic flux is provided by permanent magnets. Further, a bearing control unit, may be provided configured to receive the attitude from said flywheel attitude sensor, and calculate one or more features of the magnetic flux needed based on said attitude of the flywheel. In one embodiment, the bearing control unit may form part of a main control unit of the vehicle or may be a standalone unit in communication with the main control unit of the vehicle.
In one embodiment herein, the bearing control unit, may be configured to receive the attitude from said flywheel attitude sensor, receive the status of stopper device being inactive, calculate precision velocity, and calculate one or more feature of the magnetic flux needed based on said attitude of the flywheel and said precision velocity. Since, during the inactive state of the stopper device the precession action of the CMG is operational, a precession velocity may be calculated before deciding/calculating the magnetic flux needed for levitation of the flywheel. Further, the bearing control unit is configured to calculate a tolerance index indicative of a level of accuracy needed for maneuvering of said flywheel. Since, the level of accuracy needed in levitation when the stopper device is engaged is higher the bearing control unit may be so configured. i.e. the bearing control unit may be configured to maintain a higher tolerance index when said stopper device is inactive as compared to when the said stopper device is active.
Figure 3, illustrates a method maneuvering a flywheel of a control moment gyroscope(CMG), in a magnetic bearing system for a two wheeler having self balancing features using a control moment gyroscope(CMG).
As per an embodiment herein the method may comprise the step of starting 301 the spinning of the flywheel using a rotating means. The flywheel of a CMG may be spun about a flywheel axis using various means such as motor, engine, or any means for providing rotational energy for the spin, a torque. A desired RPM threshold as needed

for the balancing of the vehicle may be achieved at a particular spin velocity of the flywheel. Further step in one embodiment may comprise of intermittently receiving 303 the attitude of the flywheel in reference to a housing of the CMG. A flywheel is a part of a CMG system. A housing helps provide a physical boundary of a flywheel within a CMG. However, to ensure that the flywheel has an attitude as desired, an attitude sensor may be used.
Further, in one embodiment, the flywheel may be levitated. Step involves levitating 305 the flywheel by intermittently altering a current in a magnetic flux inducing coil, configured to alter the attitude of the flywheel within a prescribed threshold limit for contactless rotation. The bearing control unit may keep stored limits of the housing, and thus keep the flywheel within prescribed threshold limit for the safety of the flywheel. The magnetic flux provided may be calculated keeping various weights and speed of the flywheel involved. This ensures that the flywheel shaft is rotating without physical contact with a physical bearing, such as an auxiliary bearing. Also, the body of the flywheel does not touch the inner sides of the housing.
In an embodiment, the method may involve step of checking the status of a stopper device configured to stop the precision shaft of the CMG while the flywheel continues in spinning condition. This may be achieved by holding/stopping the precession shaft that provides precession torque to the CMG. In one exemplary embodiment, the method of stopping the precession may be as referred in Indian patent application number 201821002735.
In one embodiment, when the stopper device is inactive, hence the precession action of the CMG is active, following steps may be performed: receiving the attitude from said flywheel attitude sensor, receiving the status of the stopper device being inactive, calculating a precision velocity, and calculating one or more features of the magnetic flux needed based on said attitude of the flywheel and said precision velocity. A magnetic flux needed when the stopper device is active (hence precession is stopped) may be required to be highly accurate since the flywheel and CMG is expected to be non-existent to the vehicle. In such cases the magnetic flux may have a feature of being strong and accurate to reduce the chances of error. In one embodiment, this may be

done by calculating a tolerance index indicative of a level of accuracy needed for maneuvering of said flywheel. Further, as discussed above, maintaining a higher tolerance index when said stopper device is inactive as compared to when the said stopper device is active may take place.
In one embodiment, the steps may involve slowing down of a flywheel. This may be done by enabling supporting or slowing down of a flywheel using an auxiliary bearing. Furthermore, sending a reverse spin signal to the flywheel spin motor for quick slowing down of said flywheel may take place.
Figure 4 illustrates the assembly of the two CMG’s with opposite spin and precision on the vehicle as per an embodiment herein. As seen the two CMGs are so configured to have the yaw component cancel out based on the spin direction and the direction in which they are installed. The roll component of both the CMGs gets added.
An important aspect of this invention is the flywheel attitude sensors, active magnetic bearings (coils which generate magnetic field when current is passed through them), Passive magnetic bearings (permanent magnets which done not need electricity for generating magnetic field), magnetized flywheel/shaft and the control unit. Here the flywheel/ shaft are magnetized so that they can be moved by repelling / attracting magnetic fields from the magnetic bearing coils.

We/I claim:
1. A magnetic bearing system for a two wheeler having self balancing features using a
control moment gyroscope(CMG), comprising:
A flywheel attitude sensor of a flywheel of said CMG, configured to sense the attitude of the flywheel in reference to a housing of the CMG;
a magnetic bearing comprising a magnetic flux inducing coil, configured to alter the attitude of the flywheel;
A bearing control unit, configured to receive the attitude from said flywheel attitude sensor, and calculate one or more features of the magnetic flux needed based on said attitude of the flywheel.
2. The system as in claim 1, wherein the flywheel is of a material that is maneuverable based on a magnetic flux.
3. The system as in claim 1, wherein a precision action of a control moment gyroscope is stoppable by using a stopper device while flywheel continues in spinning condition.
4. The system as in 3, wherein the bearing control unit, is configured to receive the attitude from said flywheel attitude sensor, receive the status of the stopper device, calculate one or more feature of the magnetic flux needed based on said attitude of the flywheel and the status of the stopper device.
5. The system as in claim 4, wherein the bearing control unit, is configured to receive the attitude from said flywheel attitude sensor, receive the status of stopper device being inactive, calculate precision velocity, and calculate one or more feature of the magnetic flux needed based on said attitude of the flywheel and said precision velocity.
6. The system as in 1, further comprising an auxiliary bearing configured to provide support to a shaft of the flywheel during magnetic bearing failure, and for slowing of said flywheel.
7. The system as in 1, further comprising a flywheel spin motor in CMG, for providing a spin torque.

8. The system as in 1, wherein the bearing control unit is configured to provide a reverse spin signal to the flywheel spin motor for quick slowing down of said flywheel.
9. The system as in claim 1, wherein the bearing control unit is configured to calculate a tolerance index indicative of a level of accuracy needed for maneuvering of said flywheel.
10. The system as in claim 9, wherein the bearing control unit is configured to maintain a higher tolerance index when said stopper device is inactive as compared to when the said stopper device is active.
11. A method maneuvering a flywheel of a control moment gyroscope(CMG), in a magnetic bearing system for a two wheeler having self balancing features using a control moment gyroscope(CMG), comprising the steps of:
starting the spinning of the flywheel using a rotating means;
intermittently receiving the attitude of the flywheel in reference to a housing of the CMG;
levitating the flywheel by intermittently altering a current in a magnetic flux inducing coil, configured to alter the attitude of the flywheel within a prescribed threshold limit for contactless rotation.
12. The method as in 11, further comprising the steps of:
intermittently checking and maintaining the RPM of the said flywheel.
13. The method as in 11, further comprising the steps of: intermittently checking the status of a stopper device configured to stop the precision shaft of the CMG while flywheel continues in spinning condition.
14. The method as in 13, further comprising the steps of: receiving the attitude from said flywheel attitude sensor, receiving the status of the stopper device being inactive, calculating a precision velocity, and calculating one or more features of the magnetic flux needed based on said attitude of the flywheel and said precision velocity.
15. The method as in 13, further comprising the steps of: receiving the attitude from said flywheel attitude sensor, receiving the status of stopper device being inactive, calculating

the precision velocity, and calculating one or more feature of the magnetic flux needed based on said attitude of the flywheel and said precision velocity.
16. The method as in 11, further comprising the steps of: enabling supporting or slowing down of a flywheel using an auxiliary bearing.
17. The method as in 11, further comprising the steps of:
signaling a flywheel spin motor in CMG, for providing a spin torque.
18. The method as in 11, further comprising the steps of: sending a reverse spin signal to the flywheel spin motor for quick slowing down of said flywheel.
19. The method as in 11, further comprising the steps of: calculating a tolerance index indicative of a level of accuracy needed for maneuvering of said flywheel.
20. The method as in 19, further comprising the steps of: maintaining a higher tolerance index when said stopper device is inactive as compared to when the said stopper device is active.