US20080272265A1

US20080272265A1 - Motion platform assembly

Info

Publication number: US20080272265A1
Application number: US11/797,362
Authority: US
Inventors: Thomas J. Ciesielka; Sean P. MacDonald; Michael Boardman
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-05-02
Filing date: 2007-05-02
Publication date: 2008-11-06

Abstract

A motion platform assembly having a motion platform including a user support assembly. The motion platform being rotatable about a plurality of bearing axes which are perpendicular or aligned with the user support assembly.

Description

TECHNICAL FIELD

The present invention is directed to a motion platform assembly for flight or vehicle simulation, and more particularly, to a modular motion platform assembly having three degrees of freedom, the axes of which are perpendicular or aligned and intersect with a user support assembly.

DESCRIPTION OF THE RELATED ART

Motion platforms are generally used in flight or vehicle simulators to provide the user with a movement experience similar to that encountered during actual flight or other vehicle transport. Conventional motion platforms are capable of supporting one or more users on a platform or box situated above the axes of rotation and provide for displacement or movement of the users about a plurality of degrees of freedom, such as, pitch, roll, yaw, surge, sway and heave. However, depending upon the application and the motion to be simulated, it is not necessary to utilize all six degrees of freedom in every instance.
For example, U.S. Pat. No. 6,445,960 to Borta discloses a motion platform having two degrees of freedom, pitch and roll. The motion platform disclosed in Borta comprises a base, a top, a pair of motor assemblies mounted to the base, and an arm assembly extending between each of the positioning arm assemblies and the top of the platform. Each of the arm assemblies is responsive to rotary motion of a respective one of the positioning motor assemblies and includes a rotating arm mounted at one end on the motor shaft and rotatable over a full 360-degree arc. When a user module is mounted on the motion platform, a beam of the top serves as the seat for the user. Thus, while the user is seated on the top of the motion platform, the motion imparted to the platform originates from below the user and is translated to the top by the respective arm assemblies. As such, the center of rotation about the respective axes is outside the user module.
Similarly, U.S. Pat. No. 7,033,176 to Feldman et al. discloses a motion platform system and a method of rotating the motion platform system about plural axes. The motion platform system includes a motion platform rotatable about a plurality of bearing axes and a support structure supporting the platform. The motion platform further includes an intermediate frame supported by the support, where the intermediate frame is rotatable about a first bearin axis with respect to the support. The motion platform further includes an inner frame supported by the intermediate frame, where the inner frame is rotatable about a second bearing axis with respect to the intermediate frame. Rotation of the inner and intermediate frames about the first and second bearing axes facilitates rotation of the inner frame with respect to the support about at least one axis offset from the bearing axes.
It is clear to one skilled in the art that the simulation of movement will be more realistic if the axes of rotation are perpendicular or aligned with the user of the motion platform. There exists a need therefore for a motion platform assembly which can provide a more realistic simulation of movement.

SUMMARY OF THE INVENTION

These and other objects of the invention accomplished by using the advantages of a balanced mechanical configuration employing the center of mass principles combined with a modular chasis that can be configured for one, two, or three axes of motion. More particularly, these needs are provided by a motion platform assembly having a motion platform including a user support assembly which forms a containment chamber within which the user is situated, said motion platform being rotatable about a plurality of bearing axes which are perpendicular or aligned with a user when seated in the user support assembly. In a preferred embodiment, the motion platform assembly comprises an outer roll frame rotatable about a first bearing axis, an intermediate yaw frame rotatable about a second bearing axis, and an inner pitch frame rotatable about a third bearing axis. The first and third bearing axes are perpendicular to the user when seated in the user support assembly and the second bearing axis is aligned with the user when seated in the user support assembly.
In a preferred embodiment, a plurality of knuckle assemblies are used to interconnect the construction assemblies. More particularly, the outer roll assembly is connected to a base assembly by a first and a second knuckle assembly, the intermediate yaw assembly is connected to the outer roll assembly by a third knuckle assembly, and the inner pitch assembly is connected to the intermediate yaw assembly by a fourth and a fifth knuckle assembly. Preferably, each knuckle assembly comprises a bearing housing having opposing side parts, a bear rod disposed through the bearing housing, a linear bearing assembly disposed on each end of the bearing rod, and a thrust bearing assembly disposed between the linear bearing assemblies.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

These and other objects, features, and advantages of the present invention will become more readily apparent to those skilled in the art upon reading the following detailed description, in conjunction with the appended drawings in which:

FIG. 1 is a left perspective view of a motion platform assembly.

FIG. 2 is a right perspective view of the motion platform assembly, without the steering assembly.

FIG. 3 is a perspective view of the framework of the motion platform assembly.

FIG. 4 is an exploded view of the knuckle assembly of the motion platform assembly.

FIG. 5 is an exploded view of the knuckle assembly of the motion platform assembly according to a further embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1 and 2, the present invention is directed to a motion platform assembly for flight or vehicle simulation, as shown generally by reference numeral 10. The motion platform assembly is preferably capable of three degrees of freedom, pitch, roll and yaw, and the axes of motion are perpendicular or aligned with the user. The chassis of the motion platform assembly 10 comprises a base assembly 12, an outer roll assembly 14, an intermediate yaw assembly 16 and an inner pitch assembly 18, all of which are connected by way of a plurality of bearing or knuckle assemblies 20, as described in further detail below. The base assembly 12 includes a floor support 22 and opposing vertical base stanchions 24 preferably disposed at the front and rear of the motion platform assembly 10. The front and rear vertical base stanchions 24 a, 24 b are connected to the roll assembly 14 by knuckle assemblies 20 a, 20 b. The yaw assembly 16 is connected to the roll assembly 14 by a single knuckle assembly 20 c, and the pitch assembly 18 is connected to the yaw assembly 16 by knuckle assemblies 20 d, 20 e. A seat assembly 26 or other support for a user is mounted on a motion platform 28 connected to the pitch assembly 18. The seat assembly 26 includes a seat 30 or the like for accommodating a user and a steering or control assembly 34 is preferably positioned in front of the seat for easy access by the user (shown in FIG. 1).
Movement of the roll, yaw, and pitch assemblies 14, 16, 18 is provided by a plurality of linear actuators 32. As shown in FIG. 1, the roll axis A_ris defined between the knuckle assemblies 20 a, 20 b. A linear actuator 32 a is preferably mounted on the base assembly 12 and connected to an upper extension plate 14 a the roll assembly 14 for movement of the roll assembly 14 about the roll axis A_r. The yaw axis A_yis defined vertically through knuckle assembly 20 c. A linear actuator 32 b is preferably mounted on a lower extension plate 14 b of the roll assembly 14 and connected to the yaw assembly 16 by way of a plate 16 a for movement of the yaw assembly 16 about the yaw axis A_y. Similarly, the pitch axis A_pis defined between the knuckle assemblies 20 d, 20 e. A linear actuator 32 c is preferably mounted on a rearward extension plate 16 b of the yaw assembly 16 and connected to the rear of the seat assembly 26 for movement of the pitch assembly 18 about the pitch axis A_p. As illustrated, the roll axis and the pitch axis will pass perpendicularly through a user seated in the seat assembly. The yaw axis will pass vertically through a user seated in the seat assembly. Hence, unlike the prior art systems which provided the motion axes below the user, the present invention provides the motion axes perpendicular to or aligned with the occupant of the motion platform assembly in order to provide a more realistic flying or driving simulation experience. A primary feature of the present invention which enables this desired motion to be accomplished, is being able to maintain the fixed position and orientation of the axes by way of the knuckle assemblies. The knuckle assembly connects two elements of the motion platform assembly and maintains a mechanically controlled fixed distance and allows frictionless coplanar rotation between the elements regardless of orientation. Moreover, the use of linear actuators which translate the linear movement of the axes into a given rotational or angular motion allows for variability in the range of motion. That is, each assembly may move within a predefined rotational or angular range rather than having a fixed configuration dictating the rotational and angular movement.
Knuckle assemblies 20 are, in essence, bearing assemblies about which the respective assemblies 14, 16 and 18 rotate. Referring to FIG. 4, each knuckle assembly 20 preferably includes a bearing housing 36, two pairs of linear bearings 38 a, 38 b, and a thrust bearing 40 disposed therebetween. The linear bearings 38 a, 38 b are preferably roller bearings which interconnect the left side of the housing 36 a and the right side of the housing 36 b, although ball bearings, needle bearings and others would also be suitable. The thrust bearing 40 is provided to minimize changes in orientation caused by counter movement of the respective assembly. The thrust bearing 40 is preferably disposed in the middle of the knuckle assembly, with a washer 44 on each side thereof. The linear bearings 38 a, 38 b are preferably disposed on each end of the bearing rod 46, with a spacer ring 42 therebetween. A clip 48 is illustrated on each end of the bear rod so as to maintain the position of the bearing assemblies. FIG. 5 illustrates a further embodiment of the knuckle assembly in which a bushing 50 preferably having a shoulder 51 is disposed on each end of the bearing rod (not shown), rather than the linear bearings 38 as shown in FIG. 4. The knuckle assemblies are mounted onto the respective assemblies with a cooperating mounting clamp 54 and a plurality of fasteners 56 extending into the respective assembly. Since the assembly frames are preferably a hollow tube, that is generally made from aluminum, chromemoly, stainless steel or other suitable structured materials, including plastics, a blocking material or the like is provided within the tube to provide increased strength and rigidity. Fasteners are also used to clamp the bearing housing 36 to the cooperating mounting clamp 54.
The design of the motion platform assembly is constructed in such a manner so as to provide minimal framing for a three degree of freedom assembly. This is accomplished by utilizing the inherent advantages of a balanced assembly.
The chassis design of the motion platform assembly also encompasses the design element of modularity so that it can be adjusted in any direction and to any size without affecting the overall functionality. That is, the chassis is completely scaleable and can be made smaller or larger without effecting the overall performance of the motion platform assembly. Further, the axes or degrees of freedom through which the motion platform assembly operates can be chosen depending upon the specified application to provide one degree of freedom, i.e., only roll, or two degrees of freedom, i.e., only roll and pitch, or three degrees of freedom. Other advantages of this modularity include the ability for customization of the control system regardless of the stroke length or range of motion and it is a direct factor in the scaleability of the system.
Although only preferred embodiments and examples are specifically illustrated and described herein, it will be appreciated that many modifications and variations of the present invention are possible in light of the above teachings and within the purview of the appended claims without departing from the spirit and intended scope of the invention.

Claims

1. A motion platform assembly comprising:

a motion platform including a user support assembly within which a user is situated;

wherein said motion platform is rotatable about a plurality of bearing axes which are perpendicular or aligned with the user when seated in the user support assembly.

2. The assembly of claim 1, wherein said motion platform comprises:

an outer roll assembly rotatable about a first bearing axis;

an intermediate yaw assembly rotatable about a second bearing axis; and

an inner pitch assembly rotatable about a third bearing axis;

wherein said first and third bearing axes are perpendicular to the user when seated in the user support assembly and said second bearing axis is aligned with the user when seated in the user support assembly.

3. The assembly of claim 2, wherein said outer roll assembly is connected to a base assembly by a first and a second knuckle assembly.

4. The assembly of claim 3, wherein said intermediate yaw assembly is connected to said outer roll assembly by a third knuckle assembly.

5. The assembly of claim 4, wherein said inner pitch assembly is connected to said intermediate yaw assembly by a fourth and a fifth knuckle assembly.

6. The assembly of claim 5, wherein each said knuckle assembly comprises a bearing housing having opposing side parts, a bearing rod disposed through said bearing housing, a linear bearing assembly disposed on each end of said bearing rod, and a thrust bearing assembly disposed between said linear bearing assemblies.

7. The assembly of claim 6, wherein each said linear bearing assembly includes opposing first and second linear bearings and a spacer ring disposed therebetween.

8. The assembly of claim 6, wherein said thrust bearing assembly includes a thrust bearing and a washer disposed on each side thereof.

9. The assembly of claim 5, wherein each said knuckle assembly comprises a bearing housing having opposing side parts, a bearing rod disposed through said bearing housing, a bushing assembly disposed on each end of said bearing rod, and a thrust bearing assembly disposed between said bushing assemblies.

10. The assembly of claim 2, wherein said motion platform further comprises a plurality of actuators for rotating each of said assemblies about a respective bearing axis.

11. The assembly of claim 2, wherein said plurality of bearing axes define three degrees of freedom.

12. A modular motion platform assembly comprising:

a modular motion platform including a user support assembly within which a user is situated;

wherein said motion platform is rotatable about at least one bearing axis which is perpendicular or aligned with the user when seated in the user support assembly.

13. The modular assembly of claim 12, further comprising a first assembly rotatable about said at least one bearing axis, said first assembly selected from the group consisting of an outer roll assembly, an intermediate yaw assembly rotatable and an inner pitch assembly.

14. The modular assembly of claim 12, wherein said at least one bearing axis defines a first degree of freedom.

15. The modular assembly of claim 12, wherein said at least one bearing axis comprises two bearing axes defining two degrees of freedom.

16. The modular assembly of claim 12, wherein said at least one bearing axis comprises three bearing axes defining three degrees of freedom.