DESC:Technical Field of Invention
The present invention relates to a motion platform system and a method which imparts controlled motion to a movable platform along and about any of three axes.
Background of the Invention
In conventional motion platform systems, all the actuators are to be activated to achieve single and/or lesser degrees of freedom for different applications. Furthermore, the design of the conventional motion simulators are highly complex. Maintenance and upkeep costs associated with these complex simulators are also high. Moreover, the actuators employed in the conventional motion simulators are of a high power rating, thereby leading to excessive power consumption and an increase in the operating cost.
Brief Summary of the Invention
It is an objective of the present invention to provide a motion platform system having relatively low cost, structurally simple, whose performance characteristics can be optimized during its use.
An advantageous feature of the present invention is its usability in applications requiring lesser degrees of freedom. The present subject matter relates to a motion platform system and a method for displacing a movable platform in six degrees of freedom, both along and about all three coordinate axes.
According to an aspect of the present invention, the motion platform system includes a fixed base, a movable platform mounted over the fixed base via at least three actuators, namely a first actuator, a second actuator, and a third actuator. The second and the third actuators are positioned in a parallel line to its ‘X’ axis of a base plane and a movable platform plane. The first actuator is positioned on its ‘Y’ axis perpendicular to the ‘X’ axis of the base plane and the movable platform plane.

According to the same aspect, a fourth actuator is used which extends from a joint provided on the first actuator in a divergent direction to a spaced apart location on the fixed base.

According to the same aspect, a fifth actuator is used which extends from a joint provided on the first actuator in a divergent direction to a spaced apart location on the fixed base.

According to the same aspect, a sixth actuator is used which extends from a joint provided on the second actuator in a divergent direction to a spaced apart location on the fixed base.

Brief Description of Drawings:
FIG. 1 shows an isometric view of a motion platform system
FIG. 2 shows an isometric view of the motion platform system without movable platform.
Detailed Description of the Invention
It is to be understood that the present disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description. The present disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

On the contrary, it is intended to cover alternatives, modifications and equivalents. Various modifications to the present invention will be readily apparent to a person skilled in the art, and can be made to the present invention within the spirit and scope of the invention.

The present invention relates to a motion platform system and a method for displacing a movable platform in six degrees of freedom, along and about three coordinate axes. The movable platform may be used to mount a payload or an enclosure. The arrows marked as ‘X’, ‘Y’ and ‘Z’ in figures 1 and 2 denote the axes in the base plane about which a movable platform, may be a rotationally moved to simulate pitch, roll and yaw motion respectively, and along which the movable platform may achieve translational movement to simulate sway, surge, and heave motion respectively.

As shown in FIG.1 and FIG.2, the motion platform system (100) of the present subject matter includes a movable platform (10) which is disposed above a fixed base (11) in a manner as to be spaced apart via six actuators. The movable platform (10) holds the payload while the fixed base (11) serves to provide stability to the entire motion platform system. The second actuator (2) and the third actuator (3) are connected to the base plane (11) in an upright position along the ‘X’ axis. The first actuator (1) is connected to the base plane (11) in an upright position along the ‘Y’ axis.

One end of each of the second actuator (2) and the third actuators (3) are connected to the movable platform (10) at a point along the ‘X’ axis of the movable platform plane with joints (2a) and (3a) respectively. Other end of each of the second actuator (2) and the third actuators (3) are connected to the fixed base (11) at a point along the ‘X’ axis of the base plane with joints (2b) and (3b) respectively. Similarly, one end of the first actuator (1) is connected to the movable platform (10) at a point on ‘Y’ axis of the movable platform plane with a joint (1a). Other end of the first actuator (1) is connected to the fixed base (11) at a point on ‘Y’ axis of the base plane with a joint (1b).

As shown in FIG.2, one end of the fourth actuator (4) is connected to the body of the first actuator (1) with a joint (4a). Other end of the fourth actuator (4) is connected to the fixed base (11) with a joint (4b).

As shown in FIG.2, one end of the fifth actuator (5) is connected to the body of the first actuator (1) with a joint (5a). Other end of the fifth actuator (5) is connected to the fixed base (11) with a joint (5b).

As shown in FIG.2, one end of the sixth actuator (6) is connected to the body of the second actuator (2) with a joint (6a). Other end of the sixth actuator (6) is connected to the fixed base (11) with a joint (6b).

All the actuators used in this movable platform system are preferably linear actuators controlling translational or rotational freedom of the movable platform (10) along and about any of ‘X’, ‘Y’ and ‘Z’ axes relative to the fixed base (11). All the joints used in this movable platform system are freely movable joints preferably universal joints, however it would be understood by those skilled in the art that any other types of actuators and joints may be employed without departing from scope of the invention.

The rotational freedom of the motion about ‘X’ axis, i.e. a pitch is attained by activating the first actuator (1), the second actuator (2) and the third actuators (3). Operationally, to attain the pitch (negative or positive) the first actuator (1) is extended and the second actuator (2) and the third actuator (3) are retracted or vice versa, thereby the movable platform (10) is tilted forward and backward with respect to the fixed base (11).

Further, the rotational freedom of motion about ‘Y’ axis, i.e. a roll is attained by activating the second actuator (2) and the third actuator (3). Operationally, to attain the roll (negative or positive) the second actuator (2) is extended and the third actuator (3) is retracted or vice versa, thereby the movable platform (10) is tilted side to side with respect to the fixed base (11).

Further, the translational freedom of motion along ‘Z’ axis, i.e. a heave is attained by activating the first actuator (1), the second actuator (2) and the third actuators (3). Operationally, to attain heave the first actuator (1), the second actuator (2), and the third actuator (3) are either extended or retracted simultaneously along ‘Z’ axis, thereby the movable platform (10) is raised up and down with respect to the fixed base (11).

Further, the translational freedom of motion along the ‘Y’ axis, i.e. surge is attained by activating the fourth actuator (4). Operationally, to attain the surging feel the fourth actuator (4) alone is either extended or retracted; thereby the movable platform (10) is displaced forward and backward with respect to the fixed base (11).

Further, the translational freedom of motion along ‘X’ axis, i.e., sway is attained by activating the fifth actuator (5) and the sixth actuator (6). Operationally, to attain the sway the fifth actuator (5) and the sixth actuator (6) are either extended or retracted simultaneously, thereby the movable platform (10) is displaced left and right with respect to the fixed base (11).

Further, the rotational freedom of motion about ‘Z’ axis, i.e. yaw is attained by activating the fifth actuator (5) and the sixth actuator (6). Operationally, to attain the yaw (negative or positive) the fifth actuator (5) is extended and the sixth actuator (6) is retracted or vice versa creating a feel of rotation about ‘Z’ axis, thereby the movable platform (10) is turned left and right with respect to the fixed base (11).

The size and shape of the movable platform (10) and the fixed base (11) shown in accompanying diagrams are exemplary, it will be apparently understood by those skilled in the art that the size and shape of the movable platform (10) and the fixed base (11) can be changed as per the requirement depending upon the type of payload to be placed over the movable platform (10). By the way of an example, in case of a driving training simulator a dummy cabin of a light or heavy vehicle may be placed over the movable platform (10) of the motion platform system as a payload.

Although the present invention has been described in terms of certain preferred embodiments and illustrations thereof, other embodiments and modifications to preferred embodiments may be possible that are within the principles and spirit of the invention. The above descriptions are therefore to be regarded as illustrative and not restrictive. ,CLAIMS:We Claim:

1. A motion platform system and method configured to provide at least one degree of freedom along and about any of three axes, comprising:
a fixed base (11);
a movable platform (10) operably disposed over the fixed base (11) in a manner as to be spaced apart via at least a first actuator (1), a second actuator (2), and a third actuator (3);
the said first actuator (1) being positioned on ‘Y’ axis perpendicular to ‘X’ axis of a base plane and a movable platform plane, and
the said second actuator (2), and the said third actuator (3) being positioned on a line parallel to ‘X’ axis of the said base plane and the said movable platform plane;
wherein the said first actuator (1), the second actuator (2), and the said third actuator (3) having capability of controlling at least one degree of rotational freedom about ‘X’ and ‘Y’ axes, and a translational freedom along ‘Z’ axis;

a fourth actuator (4) extending from a joint (4a) provided on the said first actuator (1) in a divergent direction to a spaced apart location on the said fixed base (11);

a fifth actuator (5) extending from a joint (5a) provided on the said first actuator (1) in a divergent direction to a spaced apart location on the said fixed base (11);

a sixth actuator (6) extending from a joint (6a) provided on the said second actuator (2) in a divergent direction to a spaced apart location on said fixed base (11); and

wherein the said fourth actuator (4), the said fifth actuator (5), and the said sixth actuator (6) having capability of controlling at least one degree of translational freedom along the ‘X’ and ‘Y’ axes, and a rotational freedom about the ‘Z’ axis.

2. The system and method of claim 1, wherein the said second actuator (2) and the third actuator (3) having an end is connected to the movable platform (10) at a point on parallel to the ‘X’ axis of the movable platform plane with joints (2a) and (3a), and another end is connected to said fixed base (11) at a point on parallel to the ‘X’ axis of the base plane with joints (2b), and (3b) respectively.

3. The system and method of claim 1, wherein the said first actuator (1) having an end, is connected to the movable platform (10) at a point along the ‘Y’ axis of the movable platform plane with a joint (1a), and another end is connected to said fixed base (11) at a point along the ‘Y’ axis of the base plane with a joint (1b).

4. The system and method of claim 1, wherein the said fourth actuator (4), fifth actuator (5), and the said sixth actuator (6) being fastened to said fixed base (11) using joints (4b), (5b), and (6b) respectively.

5. The system and method of claim 1 to 6, wherein the said joints (1a), (1b), (2a), (2b), (3a), (3b), (4a), (4b), (5a), (5b), (6a), (6b) being universal joints.

6. The system and method of claim 1, wherein the said first actuator (1), second actuator (2), third actuator (3), fourth actuator (4), fifth actuator (5), and the said sixth actuators (6) being linear actuators.

7. The system and method of claim 1, wherein the said degree of rotational freedom is provided by the said first actuator, second actuator, and the said third actuator and therein includes a pitch and a roll along the ‘X’, and ‘Y’ axes respectively.

8. The system and method of claim 1, wherein the said translational freedom provided by said first actuator, second actuator, and the said third actuator includes a heave along the ‘Z’ axis.

9. The system and method of claim 1, wherein the said degree of translational freedom provided by the said fourth actuator includes a surge along the ‘Y’ axis respectively.

10. The system and method of claim 1, wherein said rotational freedom is provided by the said fifth actuator and sixth actuators and includes a yaw along the ‘Z’ axis.