Dynamics and control of robotic systems for assembly sets

Author(s):  
W.B. Gao ◽  
S.P. Chan
1991 ◽  
Vol 113 (3) ◽  
pp. 379-387 ◽  
Author(s):  
H. Kazerooni ◽  
S. L. Mahoney

This article describes the dynamics, control, and stability of extenders, robotic systems worn by humans for material handling tasks. Extenders are defined as robot manipulators which extend (i.e., increase) the strength of the human arm in load maneuvering tasks, while the human maintains control of the task. Part of the extender motion is caused by physical power from the human; the rest of the extender motion results from force signals measured at the physical interfaces between the human and the extender, and the load and the extender. Therefore, the human wearing the extender exchanges both power and information signals with the extender. The control technique described here lets the designer define an arbitrary relationship between the human force and the load force. A set of experiments on a two-dimensional non-direct-drive extender were done to verify the control theory.


2004 ◽  
Vol 127 (4) ◽  
pp. 537-549 ◽  
Author(s):  
Jason M. Stevens ◽  
Gregory D. Buckner

During the past 20years, tremendous advancements have been made in the fields of minimally invasive surgery (MIS) and minimally invasive, robotically assisted (MIRA) cardiac surgery. Benefits from MIS include reduced pain and trauma, reduced risks of post-operative complications, shorter recovery times, and more aesthetically pleasing results. MIRA approaches have extended the capabilities of MIS by introducing three-dimensional vision, eliminating hand tremors, and enabling the precise articulation of smaller instruments. These advancements come with their own drawbacks, however. Robotic systems used in MIRA cardiac procedures are large, costly, and do not offer the miniaturized articulation necessary to facilitate tremendous advancements in MIS. This paper demonstrates that miniature actuation can overcome some of the limitations of current robotic systems by providing accurate, repeatable control of a small end effector. A 10× model of a two link surgical manipulator is developed, using antagonistic shape memory alloy wires as actuators, to simulate motions of a surgical end-effector. Artificial neural networks are used in conjunction with real-time visual feedback to “learn” the inverse system dynamics and control the manipulator endpoint trajectory. Experimental results are presented for indirect, on-line learning and control. Manipulator tip trajectories are shown to be accurate and repeatable to within 0.5mm. These results confirm that SMAs can be effective actuators for miniature surgical robotic systems, and that intelligent control can be used to accurately control the trajectory of these systems.


2018 ◽  
Vol 4 (5) ◽  
pp. 7
Author(s):  
Shivam Dwivedi ◽  
Prof. Vikas Gupta

As the four-wheel steering (4WS) system has great potentials, many researchers' attention was attracted to this technique and active research was made. As a result, passenger cars equipped with 4WS systems were put on the market a few years ago. This report tries to identify the essential elements of the 4WS technology in terms of vehicle dynamics and control techniques. Based on the findings of this investigation, the report gives a mechanism of electronically controlling the steering system depending on the variable pressure applied on it. This enhances the controlling and smoothens the operation of steering mechanism.


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