168,414 research outputs found

    Task Space Angular Velocity Blending for Real-Time Trajectory Generation

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    The invention is embodied in a method of controlling a robot manipulator moving toward a target frame F(sub 0) with a target velocity v(sub 0) including a linear target velocity v and an angular target velocity omega(sub 0) to smoothly and continuously divert the robot manipulator to a subsequent frame F(sub 1) by determining a global transition velocity v(sub 1), the global transition velocity including a linear transition velocity v(sub 1) and an angular transition velocity omega(sub 1), defining a blend time interval 2(tau)(sub 0) within which the global velocity of the robot manipulator is to be changed from a global target velocity v(sub 0) to the global transition velocity v(sub 1) and dividing the blend time interval 2(tau)(sub 0) into discrete time segments (delta)t. During each one of the discrete time segments delta t of the blend interval 2(tau)(sub 0), a blended global velocity v of the manipulator is computed as a blend of the global target velocity v(sub 0) and the global transition velocity v(sub 1), the blended global velocity v including a blended angular velocity omega and a blended linear velocity v, and then, the manipulator is rotated by an incremental rotation corresponding to an integration of the blended angular velocity omega over one discrete time segment (delta)t

    Space-Time Cubification of Artistic Shapes.

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    This poster describes an original approach to producing artistic shapes in a cubist style. We propose mathematical models and algorithms for adding cubist features to (or cubification of) time-variant sculptural shapes as well as a practical technological pipeline embracing all the main phases of their production. A novel method is proposed for faceting and local distortion of the given artistic shape. A new concept of a 4D cubist camera is introduced for multiple projections from 4D space-time to 3D space and combining them using space-time blending to create animated sculptures. The proposed techniques are implemented and experimental results are presented

    Cubification and animation of artistic shapes

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    This poster describes an original approach to creating static and dynamic sculptures in a cubist style. We propose a novel method for faceting and local distortion thus adding cubist features and generating time-variant sculptural shapes. We introduce the concept of a 4D cubist camera for blending multiple projections from 4D space-time to 3D space. We describe a practical pipeline embracing all the main phases of production of static and dynamic cubist shapes. The proposed techniques are implemented and experimental results are presented

    Dynamic obstacle avoidance for real-time character animation

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    This paper proposes a novel method to control virtual characters in dynamic environments. A virtual character is animated by a locomotion and jumping engine, enabling production of continuous parameterized motions. At any time during runtime, flat obstacles (e.g. a puddle of water) can be created and placed in front of a character. The method first decides whether the character is able to get around or jump over the obstacle. Then the motion parameters are accordingly modified. The transition from locomotion to jump is performed with an improved motion blending technique. While traditional blending approaches let the user choose the transition time and duration manually, our approach automatically controls transitions between motion patterns whose parameters are not known in advance. In addition, according to the animation context, blending operations are executed during a precise period of time to preserve specific physical properties. This ensures coherent movements over the parameter space of the original input motions. The initial locomotion type and speed are smoothly varied with respect to the required jump type and length. This variation is carefully computed in order to place the take-off foot as close to the created obstacle as possibl

    4D Cubism: Modeling, Animation and Fabrication of Artistic Shapes

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    The paper describes an original approach to creating and producing artistic shapes in a cubist style. We propose mathematical models and algorithms for adding cubist features to (or cubification of) time-variant sculptural shapes as well as a practical technological pipeline embracing all the main phases of their production. A novel method is proposed for faceting and local distortion of the given artistic shape. A new concept of a 4D cubist camera is introduced for multiple projections from 4D space-time to 3D space and combining them using space-time blending to create animated sculptures. 3D printing for stop-motion animation is proposed as one of the final pipeline processing stages. The proposed techniques are implemented with artist friendly user interfaces and experimental results are presented

    Space shuttle post-entry and landing analysis. Volume 2: Appendices

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    Four candidate navigation systems for the space shuttle orbiter approach and landing phase are evaluated in detail. These include three conventional navaid systems and a single-station one-way Doppler system. In each case, a Kalman filter is assumed to be mechanized in the onboard computer, blending the navaid data with IMU and altimeter data. Filter state dimensions ranging from 6 to 24 are involved in the candidate systems. Comprehensive truth models with state dimensions ranging from 63 to 82 are formulated and used to generate detailed error budgets and sensitivity curves illustrating the effect of variations in the size of individual error sources on touchdown accuracy. The projected overall performance of each system is shown in the form of time histories of position and velocity error components
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