Gyro-stabilized platforms for force-feedback applications

Abstract

Force feedback in large, immersive environments is provided by device which a gyro- stabilization to generate a fixed point of leverage for the requisite forces and / or torques. In one embodiment, one or more orthogonally oriented rotating gyroscopes are used to provide a stable platform to which a force-reflecting device can be mounted, thereby coupling reaction forces to a user without the need for connection to a fixed frame. In one physical realization, a rigid handle or joystick is directly connected to the three-axis stabilized platform and using an inventive control scheme to modulate motor torques so that only the desired forces are felt. In an alternative embodiment, a reaction sphere is used to produce the requisite inertial stabilization. Since the sphere is capable of providing controlled torques about three arbitrary, linearly independent axes, it can be used in place of three reaction wheels to provide three-axis stabilization for a variety of space-based and terrestrial applications.

Description

REFERENCE TO RELATED APPLICATIONS[0001]Notice: More than one reissue application has been filed for the U.S. Pat. No. 5,754,023. The reissue applications serial numbers are: Ser. No. 11 / 782,998 (the present application), Ser. No. 09 / 452,682 (a continuation application) issued as U.S. Pat. No. RE37,374, and Ser. No. 09 / 888,291 (a continuation application) issued as U.S. Pat. No. RE39,906.[0002]This invention claims priority of U.S. Provisional Application Serial No. 60 / 005,861, filed Oct. 26. 1995, the entire contents of which are incorporated herein by reference.This application is a Continuation of U.S. patent application Ser. No. 09 / 888,291 filed Jun. 21, 2001, now Reissue Pat. No. RE39,906, which is a Continuation of U.S. patent application Ser. No. 09 / 452,682, filed Nov. 30, 1999, now Reissue Pat. No. RE37,374, which is a Reissue of U.S. Pat. No. 5,754,023, filed Oct. 22, 1996, which claims priority to U.S. Provisional Application No. 60 / 005,861 filed Oct. 26, 1995, the entire d...

AI Technical Summary

Benefits of technology

The present invention provides a device that uses gyro-stabilization to create a fixed point of leverage for the necessary forces and torques in large, immersive environments. This device can be used in various applications such as gaming, virtual and augmented reality, and sports equipment. The control structure for stabilization and force-feedback can be separate, allowing different stabilization mechanisms to be used with existing force-feedback capabilities. The invention also includes a three-axis implementation using a set of three, mutually perpendicular momentum wheels, an attitude measuring device, and a control system to maintain the platform in a fixed position.

Problems solved by technology

The entertainment field is very difficult to address with force-feedback technology, since the applications demand both higher performance and lower costs.

However, a major deficiency with all existing force-generating devices is the requirement that they be connected to a fixed frame, thus forcing immobility on the user.

Consequently, no existing force feedback device allows for easy mobility and force generation.

This problem is fundamental, since many virtual reality applications require large working volumes and the ability to move freely within these volumes, to provide realistic visual and audio feedback during walkthrough scenarios, for example.

In summary, large, immersive environments such as CAVES currently lack haptic feedback, primarily because the existing technology will not support unrestricted motion.

However, the design of a hand-held, spatially unrestricted force-feedback device is fundamentally different from existing devices, which typically use primarily electromechanical or pneumatic actuators operating against fixed supports to achieve active force feedback.

To construct an n-axis joystick, requiring 1, 2, 3 to n+3 motors, presents significant challenges, for example, since the additional motors may significantly increase the cost and / or weight of the device.

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