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The following specification particularly describes the invention, and the manner in which it is to be performed.

FIELD OF THE INVENTION

1. The present invention is directed to automatic camber mechanism, and more
particularly to automatic cambering in rocker bogie mechanism and method thereof.

BACKGROUND OF THE INVENTION

2. Space exploration is a booming area of research. In light of exploration, space agencies are frantically working on putting stable Rovers and Landers on alien planets to examine them further. The preferred suspension system for rovers is the Rocker Bogie suspension system. NASA has been using this system since it put its first rover on Mars, the Sojourner rover.

3. The inherent advantages of the suspension system make it a viable option to consider in many scenarios. The wheels of a rocker bogie mechanism are able to travel over obstacles twice the diameter of their wheel. Moreover, this mechanism also ensures that all wheels of the body remain in contact with the ground.

4. With the space race burgeoning, the application terrain of rovers is also poised to increase. Certain conditions may even demand for a vehicle to travel in caves, natural tunnels, etc. To minimise power losses to the wheels, the area of contact must be as high as possible. However, the conventional rocker bogie mechanism is unable to cope up with this hindrance and area of contact is always reduced.

5. In the background of foregoing limitations, there exists a need for a system which automatically allows the wheels to camber this suspension system, therefore being more viable and superior to the competitors located in the art.

OBJECTS OF THE INVENTION
6. It is an objective of the present invention to provide a linkage suspension system specific mechanism which substantially obviates one or more off the problems due to limitations and disadvantages of the related art.

7. It is another object of the present invention to provide a rover with a automatic camber mechanism which enables efficient power utilisation and optimise travel in curved terrain with obstacles.

8. These and other objects will become apparent from the ensuing description of the present invention.

SUMMARY OF THE INVENTION

9. According to an aspect of the present invention, an automatic cambering mechanism
for Rocker-Bogie suspension system is disclosed, comprising of a Main Control Arm
connected to a Front Control Arm and a Rear Control Arm; Three wheels in contact with
the ground.

10. According to a further aspect of the present invention, the mechanism further comprises of a bearing inserted in the Main Control Arm's side which connects it to the Front Control Arm; the presence of bearings in the Rear Control Arm is present only for the rear wheel and not the middle wheel.

11. According to another aspect of the present invention, a method of automatically adjusting the wheels in rocker-bogie suspension has been disclosed, comprising the steps of operation and principle behind it.

BRIEF DESCRIPTION OF THE DRAWINGS

12. Referring now to the drawings wherein the showings are for the purpose of illustrating embodiments of the inventions only, and not for the purpose of limiting the same.

13. Fig. 1. shows a rocker-bogie mechanism in accordance with an exemplary embodiment of the present invention.

14. Fig. 2. shows a rocker bogie mechanism schematic in accordance with an exemplary embodiment of the present invention.

15. Fig. 3. shows a simulation result for a rocker bogie mechanism containing an exemplary embodiment of the present invention.

16. Fig. 4. shows a simulation result for a rocker bogie mechanism containing an exemplary embodiment of the present invention

17. Fig. 5. shows a simulation result for a rocker bogie mechanism containing an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

18. Definitions unless defined otherwise, all technical and scientific terms used herein
have the same meaning as commonly understood by one of ordinary skill in the art to
which this invention belongs.

19. Before the present suspension system is described, it is to be understood that this disclosure is not limited to the particular suspension system as described, since it may vary within the specification indicated. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope of the present invention, which will be limited only by the appended claims. The words "comprising", "having", "containing", and "including", and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. The disclosed embodiments are merely exemplary methods of the invention, which may be embodied in various forms.

20. The present invention will be described herein below with reference to the accompanying drawings. The invention discloses a modified rocker bogie suspension system as shown in the embodiments in Figures 1 to 2. The reference numerals used in the Figures are tabulated below:

21. In an embodiment of the present invention, the suspension system comprises a Main Control Arm (301), a Front Control Arm (302) linked via a bearing to another connector which connects it to the respective wheel and is capable of being rotated about its axis with the help of servo motor (or any other constraint mechanism as
deemed appropriate by the user, who is well versed in this art, employing it), a Rear Control Arm (303). All the arms are then connected to their respective wheels. The Main Control Arm will be attached directly to the body. Fig. 4. also depicts the apparent camber of front control arm (402), but the camber is occurring directly as a result

22. The automatic cambering mechanism is heavily inspired by the working of Universal joints. The main concept of Universal joints, in turn, is based on gimbals. While it is true that a Universal joint is not a constant velocity joint, the operation speeds of rocker bogie mechanism negates the need of using a constant velocity joint, especially in an environment where camber is required. Despite the primary purpose of a Universal joint being that of transmitting motion and/or power, the final implementation of our mechanism simply uses the Universal joint as an inspiration for aiding in curving the wheels attached to the system.

23. Upon placing the system on a curved surface, the ground reaction force tends to act upwards, causing the wheels to buckle upwards fully and thereby collapsing the rover. The use of a servo motor and/or a locking mechanism prevents such failure from happening. A proper implementation of a preventive mechanism will result in the wheels cambering and adjusting to the pipe's curvature.

24. It is imperative to mention here that the use of a servo motor and/or a locking
mechanism is highly necessary for the optimal operation of the suspension system. A
servo motor can limit the amount of tilt by controlling with the help of sensors, while a
locking mechanism can be a much simpler tool. A locking mechanism (including but not
limited to snap locks, etc) can be preset in such a way by the user that the said
mechanism comes into action whenever the required tilt is reached by the invention.

25. Another innovative aspect of this invention is/are the end(s) of the connector link(s)
(402). To provide a camber, a wheel must rotate about an axis. Without the presence of
the straight portions on the links joining the wheels to the control arm, the axis of
rotation would have been at an angle to the ground, making the wheels tilt in opposite
directions. The fact that the wheel(s) is/are linked to a part whose plane is parallel to the
ground ensures that the camber provided will be at the same angle for all the wheels
applicable and that that the wheels do not tilt inwards.

26.

The unequal rotation about a non-parallel axis is the primary reason for providing the connector (connected ideally via help of bearing and lockage controlled, as mentioned previously). However, in cases where the actual height of the suspension mechanism (height from hub to reference datum) is reasonably small (approximately making the links ±10 degrees to the datum), cambering mechanism can be provided directly from the Front Control Arm, as shown in Fig. 5 (501). The tilting in this scenario will be minimal with negligible losses. This embodies another incorporation of universal joint in suspension system.
26. This innovation provides for a better power transmission capability in curved terrain. Wheels usually have a line contact on linear surfaces and that area of contact is greatly reduced when driving upon a curved surface. The provision of a cambering mechanism will provide for a greater area of contact and hence better grip and mobility.

27. Fig. 1. and Fig. 2 depict the results of simulation of the invention in the 'MATLAB' software. Fig. 1. depicts the simulation of a normal rocker bogie mechanism on a curved terrain, and Fig. 2. depicts the simulation of a rocker bogie's movements, with the said invention incorporated, over the same uneven terrain with respect to time. The fact remains that the the invention is able to provide for impeccable stability in the vehicle dynamics and is able to be practically feasible in production.

28. The incorporation of this invention is inclusive, but not limited to, of rocker bogie suspension mechanism, double lambda suspension mechanism, and other linkage based mechanisms which may be able to incorporate such methodology.
We Claim:

1) An automatic cambering mechanism for linkage based suspension systems comprising: Main control arm (101), front control arm (102), rear control arm (103), sub-control arm (104) with a bearing and/or servo motor allowing for the arms (102 and 103) to tilt and provide the camber.

2) The cambering mechanism as mentioned in claim 1 comprising further of a locking mechanism and/or servo motor for limiting the tilt of the suspension incorporating the mechanism. The locking mechanism inclusive but not limited to snap-lock mechanisms and the likes.

3) The mechanism laid in claim 1 comprising of appropriate modification for proper cambering of the vehicle. The modification inclusive of modifying the control arms to make their ends parallel to the ground as a method of providing for a stable axis of rotation and the disconnection of the linkage arms to incorporate a bearing/servo motor inside the control arms for the the wheel links to rotate.

4) A method for automatically cambering linkage suspension systems comprising of the steps:

Disconnecting the links into two and affixing the wheel links (102 and 103) into the control arms (101 and 104) by press fitting them into the bearing already inside the latter.

A locking mechanism or the use of a servo motor to prevent the wheels from collapsing them on themselves.

Placing the system in a curved environment, resulting in automatic cambering as the invention claims so.

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4) P Jr, B. M. (1970). U.S. Patent No. 3,497,233. Washington, DC: U.S. Patent and Trademark Office.

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