A formulation that makes possible the integration of collision prediction and avoidance stages for mobile robots moving in general terrains containing moving obstacles is presented. A dynamic model of the mobile robot...
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A formulation that makes possible the integration of collision prediction and avoidance stages for mobile robots moving in general terrains containing moving obstacles is presented. A dynamic model of the mobile robot and the dynamic constraints are derived. Collision avoidance is guaranteed if the distance between the robot and a moving obstacle is nonzero. A nominal trajectory is assumed to be known from off-line planning. The main idea is to change the velocity along the nominal trajectory so that collisions are avoided. A feedback control is developed and local asymptotic stability is proved if the velocity of the moving obstacle is bounded. Simulation results verify the value of the proposed strategy.< >
In the paper the problem of input-acceptance (i.e., the question of existence of a trajectory corresponding to a given input sequence) and output-uniqueness properties for a linear (respectively controlled and observe...
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In the paper the problem of input-acceptance (i.e., the question of existence of a trajectory corresponding to a given input sequence) and output-uniqueness properties for a linear (respectively controlled and observed) Implicit discrete-time system are introduced and studied. Geometric and algebraic conditions for all considered properties are provided. It is shown that the input and output notions are dual counterparts. A natural Interpretation of all the notions in terms of linear von Neumann model of economy is presented.
Prior to achieving Permanent Manned Capability (PMC), there will be thousands of hours when Space Station Freedom (SSF) will be unattended (dormant or quiescent state). This time could be used productively in many way...
Prior to achieving Permanent Manned Capability (PMC), there will be thousands of hours when Space Station Freedom (SSF) will be unattended (dormant or quiescent state). This time could be used productively in many ways. Also, during mature SSF operations, there will be many demands of the time available to station astronauts and scientists. The need for extensive ground support and continuous parallel activities during rest periods and while preparing for Intra and Extra-Vehicular Activities (IVA and EVA) presents a formidable time scheduling problem. Astronaut time is an expensive commodity and all means of reducing the demand for on-orbit operator time should be investigated.
The paper describes a manufacturing cell to dispense adhesives automatically. Adhesives have been used in a number of structurally-bonded joints and manufacturing applications. However, the need to have high-integrity...
The paper describes a manufacturing cell to dispense adhesives automatically. Adhesives have been used in a number of structurally-bonded joints and manufacturing applications. However, the need to have high-integrity structurally-bonded adhesive joints throughout industry is increasing. In order to ensure process integrity, strict process control of the automated dispensing cell is essential. This paper describes an automated cell which consists of a six-axis robot, a dispensing system, and a single axis linear table. The dispensed adhesive is controlled through a closed loop control system by using a vision system as a feedback signal. A laser 'line of light' is used as part of a vision system to monitor on-line, the bead parameters. These measurements are fed back to the controller for necessary adjustment to ensure that the bead stays within the required size.
A common problem in robotic assembly is that of mating tightly fitting parts when the locations and the dimensions of the parts are somewhat uncertain. Because the clearances allowed between mating features of parts a...
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This note ties together a new geometric theory and the previous algebraic results for the closed-loop eigenstructure assignment by output feedback in multivariable systems. Necessary and sufficient conditions for the ...
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This note ties together a new geometric theory and the previous algebraic results for the closed-loop eigenstructure assignment by output feedback in multivariable systems. Necessary and sufficient conditions for the closed-loop stabilization, eigenstructure assignment are presented. A bilinear generalized Sylvester equation is introduced, the solutions of which completely characterize the closed-loop eigenstructure problem via output feedback.
Summary form only given. An analysis of the most commonly found barriers to advancement in an engineer's career was performed. As practitioners of technology in its full context, engineers are facing the reality o...
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Summary form only given. An analysis of the most commonly found barriers to advancement in an engineer's career was performed. As practitioners of technology in its full context, engineers are facing the reality of being global professionals in this decade. Interchange of ideas with industry representatives, as well as previous related research work, has made it possible for the authors to identify the major obstacles. These are stereotypes, traditional college and corporate training programs, and corporate culture. The research indicates that engineers want to interact in depth with the social aspects of pure technology-people. An integrated approach to help engineers utilize their technical skills in management has been developed. Several players can make this possible: engineers through their own desires, universities through modification of programs and instructional methods, and corporations through enhanced training programs. An example validates the fact that engineers have an advantage when promoted to managerial levels. Their training, which stresses discipline and methodology, is indispensable in management.< >
作者：
D.B. DinerM. von SydowMan-Machine Systems
Robotics and Automation Systems Section Jet Propulsion Laboratory / NASA California Institute of Technology Pasadena CA USA
Four trained human subjects were tested for subpixel resolution capabilities, by presenting two identical 3D targets at depths differing in disparity by fractions of a pixel difference. All four observers were able to...
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Four trained human subjects were tested for subpixel resolution capabilities, by presenting two identical 3D targets at depths differing in disparity by fractions of a pixel difference. All four observers were able to use the subpixel information when evaluating the relative depth perceived between the two bars. With a viewing distance of 1.3 m, and a stereo camera rig configured to yield a pixel depth resolution of over 5 mm, the observers have demonstrated depth resolution of 1 mm. For high-precision teleoperation, that is, precision on the order of millimeters, these results may extend operator capabilities.< >
作者：
D.B. DinerMan-Machine Systems
Robotics and Automation Systems Section Jet Propulsion Laboratory / NASA California Institute of Technology Pasadena CA USA
A combination of camera configurations, image presentation techniques, and observer viewing locations is presented, providing a fully undistorted true-to-scale 3D image. A definition of orthostereopsis is suggested wh...
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A combination of camera configurations, image presentation techniques, and observer viewing locations is presented, providing a fully undistorted true-to-scale 3D image. A definition of orthostereopsis is suggested which includes parallel cameras, shifted images such that a chosen depth plane of interest is perceived to be located on the front surface of the viewing monitor, a flat viewing monitor, a monitor magnification factor such that images of objects at infinity are separated on the monitor by the observer's interocular distance, and an operator viewing distance such that the perceived depth scale matches the perceived height and width scales.< >
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