The authors extend their previous effort in visualizing the spatial aspect of relativistic effects, and treat the phenomenon of time dilation, an inherent temporal effect of special relativity. Here, the authors demon...
详细信息
The authors extend their previous effort in visualizing the spatial aspect of relativistic effects, and treat the phenomenon of time dilation, an inherent temporal effect of special relativity. Here, the authors demonstrate through still-frame images and live animations that, in observing the viewing-independent time dilation, the finite light transit time involved in performing the observation makes the observed time dilation also depend on the viewing condition. As the authors introduce the physics of special relativity into ray-tracing and make time to pass as a ray travels through space, they are able to link the spatial and temporal dimensions in a fundamental and consistent way in their simulations, and generate images that reveal the spatial and temporal properties of the 4D geometry of spacetime. The present exploration highlights the interplay of the imaging process and the imaged physical events in producing the final images.< >
In this paper, a dynamic model of a robot manipulator is first derived based on the Euler-Lagrange equation and a state-space representation is derived for it. A number of non-adaptive robot control schemes are then r...
详细信息
In this paper, a dynamic model of a robot manipulator is first derived based on the Euler-Lagrange equation and a state-space representation is derived for it. A number of non-adaptive robot control schemes are then reviewed. A robust decentralized control is then proposed for a 5-axis robot manipulator. Numerical simulation results are presented to verify the theory.
An intelligent robotic system for multi-sensor based tracking and interception of moving objects which travel at unknown velocities is presented. The capability for multi-sensor assisted object tracking has been achie...
详细信息
ISBN:
(纸本)9780819400383
An intelligent robotic system for multi-sensor based tracking and interception of moving objects which travel at unknown velocities is presented. The capability for multi-sensor assisted object tracking has been achieved through the development of techniques to track in multiple dimensions for both the static and dynamic cases. These methods are realized via the fusion of the best attributes of visual and acoustic sensing into an effective configuration that is ideal for real time tracking purposes. The kinematic information for a moving object is extracted via end effector mounted vision and ultrasonic sensors. A hybrid position/force servo-controlled gripper developed at NCSU has been used for the system implementation. One parallel actuation gripper finger houses a fiber optics based Eye-in-Hand vision sensor, while the other accommodates an ultrasonic range sensor. The primary intent of this work is to develop approaches for performing the tasks of: generalized visual/ultrasonic tracking of known rectangular entities;3-D tracking of arbitrary pseudo-planar objects that can change orientation about the optical axis;and a real time paradigm for the tracking of motion in 3-D with variable orientation about the optical axis. This discussion includes both a description of the underlying principles and the initial experimental results.
This paper describes a reliable localisation system based on ultrasonic sound, that has been designed for an autonomous robot. The robot position and orientation within a 10 meter square room can be obtained to an acc...
详细信息
Control of tool-workpiece interaction force is of vital importance in automated assembly. Using a simple linear continuous model of an edge-following system to predict the appropriate accomodation gains in a force con...
详细信息
Control of tool-workpiece interaction force is of vital importance in automated assembly. Using a simple linear continuous model of an edge-following system to predict the appropriate accomodation gains in a force control loop, previous work has shown that force control by accomodation is feasible. Following up this work, this paper describes the analysis, simulation and implementation of an adaptive force control in a two-dimensional edge-following task with a PUMA 560 robot and wrist force sensor. First, a discrete-time model of an edge-following system is developed and then used as the plant; second, a model reference adaptive control (MRAC) scheme is applied to achieve both tracking and regulation purposes. The reference (tracking) model can be determined by experimental reference input and desired model output information; the reference (regulation) model can be obtained by simulation to smooth out the plant output and improve the augmented filtered plant-model error. Study is done on the values of the adaptation gains in the adaptive mechanism, and hence can be adjusted to insure the best plant output performance.
Mathematical morphology, "algebra of shape", is used in many image processing applications including machine vision recognition, visually guided robot vision systems, biomedical image processing, and low-lev...
详细信息
Mathematical morphology, "algebra of shape", is used in many image processing applications including machine vision recognition, visually guided robot vision systems, biomedical image processing, and low-level vision problems. The fact that mathematical morphology deals with shape characteristics of an image makes it a tool for object recognition, defect detection, and feature extraction. The analogy between the morphological operations for shape and the convolution operations for signals suggests the dominance of mathematical morphology in the image processing applications related to shape, especially in machine vision.
The problem of automatically generating the possible 3-D sensor locations for observing a scene is defined, and an approach to its solution is presented. The approach taken assumes that the sensor characteristics are ...
详细信息
The problem of automatically generating the possible 3-D sensor locations for observing a scene is defined, and an approach to its solution is presented. The approach taken assumes that the sensor characteristics are well understood and that objects expected in the scene are known and modeled. Then, given a set of constraints, a set of actions is specified directing a robot arm to position itself in such a manner that an attached 3-D sensor located in the robot gripper yields the maximum information content with minimum effort with respect to the constraints. Techniques that yield solutions for placement of a triangulation-type 3-D laser range finder are presented.< >
A structure for sensory information organization and robot task planning is introduced, and HMP, a hierarchical multiprocessor computer architecture, is developed to support the real-time execution of the defined info...
详细信息
A structure for sensory information organization and robot task planning is introduced, and HMP, a hierarchical multiprocessor computer architecture, is developed to support the real-time execution of the defined information structure. Queuing network analysis indicates that this hierarchical multiprocessor computer architecture, at least for the sets of loads defined, performs better than currently proposed systems based on single buses. All classes of data, except for large video data that have longer interarrival times, are transferred within 10 milliseconds, and most data are transferred at rates that are very close to their theoretical maximum speed. The gates, used for partitioning the buses, have also been successful; data transfers among processors inside the segment isolated by the gate have been speeded up while the transfer between clusters has either stayed the same or has been reduced slightly, compared to a system without gates.< >
暂无评论