398results about "Aircraft stabilisation by gravity apparatus" patented technology

A stabilization system including a platform supported by two or more rotatably-coupled gimbal frames each having a pivot assembly disposed at its rotation axis to couple an actuator to a rotation sensor having a rotation-sensitive sensor axis that is fixedly disposed with respect to the rotation axis, and a controller including means for accepting the sensor signals and for producing each motor signal needed to dispose the platform in a predetermined angular position with respect to each rotation axis independent of changes in the base orientation. A motion simulator embodiment includes controller means for accepting an external slew signal sequence and means for producing the motor signals needed to move the platform along a predetermined sequence of positions represented by the slew signal sequence.

A guideless stage for aligning a wafer in a microlithography system is disclosed, and a reaction frame is disclosed which isolates both external vibrations as well as vibrations caused by reaction forces from an object stage. In the guideless stage an object stage is disclosed for movement in at least two directions and two separate and independently movable followers move and follow the object stage and cooperating linear force actuators are mounted on the object stage and the followers for positioning the object stage in the first and second directions. The reaction frame is mounted on a base structure independent of the base for the object stage so that the object stage is supported in space independent of the reaction frame. At least one follower is disclosed having a pair of arms which are respectively movable in a pair of parallel planes with the center of gravity of the object stage therebetween. The linear positioning forces of the actuator drive means are mounted and controlled so that the vector sum of the moments of force at the center of gravity of the object stage due to the positioning forces of the drive means is substantially equal to zero. The actuator mounting means can include at least two thin flexible members mounted in series with the primary direction of flex of the members being orthogonal to one another.

A vertical takeoff and landing (VTOL) air vehicle disclosed. The air vehicle can be manned or unmanned. In one embodiment, the air vehicle includes two shrouded propellers, a fuselage and a gyroscopic stabilization disk installed in the fuselage. The gyroscopic stabilization disk can be configured to provide sufficient angular momentum, by sufficient mass and/or sufficient angular velocity, such that the air vehicle is gyroscopically stabilized during various phases of flight. In one embodiment the fuselage is fixedly attached to the shrouded propellers. In another embodiment, the shrouded propellers are pivotably mounted to the fuselage.

A guided stage mechanism suitable for supporting a reticle in a photolithography machine includes a stage movable in the X-Y directions on a base. Laterally surrounding the stage is a rectangular window frame guide which is driven in the X-axis direction on two fixed guides by means of motor coils on the window frame guide cooperating with magnetic tracks fixed on the base. The stage is driven inside the window frame guide in the Y-axis direction by motor coils located on the stage cooperating with magnetic tracks located on the window frame guide. Forces from the drive motors of both the window frame guide and the stage are transmitted through the center of gravity of the stage, thereby eliminating unwanted moments of inertia. Additionally, reaction forces caused by the drive motors are isolated from the projection lens and the alignment portions of the photolithography machine. This isolation is accomplished by providing a mechanical support for the stage independent of the support for its window frame guide. The window frame guide is a hinged structure capable of a slight yawing (rotational) motion due to hinged flexures which connect the window frame guide members.

A method for controlling a flying projectile which rotates during flight, comprising: determining an angle of rotation of an inertial mass spinning about an axis during flight; and controlling at least one actuator for altering at least a portion of an aerodynamic structure, selectively in dependence on the determined angle of rotation and a control input, to control aerodynamic forces during flight. An aerodynamic surface may rotate and interact with surrounding air during flight, to produce aerodynamic forces. A sensor determines an angular rotation of the spin during flight. A control system, responsive to the sensor, produces a control signal in dependence on the determined angular rotation. An actuator selectively alters an aerodynamic characteristic of the aerodynamic surface in response to the control signal.

A lithographic projection apparatus includes a passive magnetic bearing configured to provide support between a first and second part of the lithographic apparatus and allow both parts to be displaced relative to each other in a direction perpendicular to the support direction. The passive magnetic bearing includes first and second magnetic assemblies. Each magnetic assembly includes at least one permanent magnet.

The universal vehicle system is designed with a lifting body which is composed of a plurality of interconnected modules which are configured to form an aerodynamically viable contour of the lifting body which including a front central module, a rear module, and thrust vectoring modules displaceably connected to the front central module and operatively coupled to respective propulsive mechanisms. The thrust vectoring modules are controlled for dynamical displacement relative to the lifting body (in tilting and/or translating fashion) to direct and actuate the propulsive mechanism(s) as needed for safe and stable operation in various modes of operation and transitioning therebetween in air, water and terrain environments.

A balanced positioning apparatus comprises a balance mass which is supported so as to be moveable in the three degrees of freedom, such as X and Y translations and rotation about the Z-axis. Drive forces in these degrees of freedom act directly between the positioning body and the balance mass. Reaction forces arising from positioning movements result in corresponding movement of the balance mass and all reaction forces are kept within the balanced positioning system. The balance mass may be a rectangular balance frame having the stators of two linear motors forming the uprights of an H-drive mounted on opposite sides. The cross-piece of the H-drive spans the frame and the positioned object is positioned within the central opening of the frame.

An unmanned air vehicle comprises a fuselage that defines aerodynamic flight surfaces, an engine mounted to the fuselage having an engine shaft arranged to rotate about a longitudinal axis with respect to the fuselage, and a propeller mounted to the engine shaft so as to rotate to thereby provide thrust. The aircraft also comprises a gyroscopic stabilization member coupled to the shaft such that rotation of the engine shaft results in rotation of the gyroscopic member. Thus, there is more stability during the entire flight envelope. In one embodiment, the gyroscopic stabilization member is comprised of a ring that is attached to the outer ends of the blades of the propeller and the ring is also selected so as to have a mass that will result in the gyroscopic stabilization member having a sufficient angular momentum so as to gyroscopically stabilize the aircraft.

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.

A refueling drogue adapted to connect to a refueling hose extending from a refueling aircraft. The drogue may include a rotatable mass adapted to effectively stabilize the refueling drogue via a gyroscopic effect of the rotating mass on the refueling drogue when the refueling drogue is placed in an airstream.

Embodiments of the invention are ideally suited for use filming movies, sporting events, or any other activity that requires fluid movement of a camera or other object to any position within a defined volume of space. To accomplish such positioning embodiments of the invention are configured to move an object throughout three-dimensional space by relocating one or more lines that are feed through a plurality of opposing sides of the object. These line(s) (e.g., a cable, rope, string, cord, wire, or any other flexible connective element) which support the object from above or below the object within a volume of space are arranged in way that allows the object to be rapidly moved to and from any location within the defined volume of space. For instance, the system may be arranged to perform dimensional movement using one line configured as an endless loop, one line configured as a half loop, two lines configured as endless loops or two lines configured as half loops. Other embodiments which split the two lines at the X and Y junctions may yield three and four rope embodiments which are in keeping with the spirit of the invention.

A system and method are provided for controlling a stepper motor having a rotor and a multi-phase stator. Sinusoidal command signals define a commanded position of the motor's rotor. An actual position of the rotor is sensed as a function of an electrical angle between the actual position and the commanded position. The actual position is defined by sinusoidal position signals. An adjustment signal is generated using the sinusoidal command signals and sinusoidal position signals. The adjustment signal is defined as a function of the cosine of the electrical angle. The adjustment signal is multiplied by each sinusoidal command signal to generate a corresponding set of excitation signals, each of which is applied to a corresponding phase of the multi-phase stator.