Redundant movements in autonomous mobility: experimental and theoretical analysis

<p>Distributed load balancers exhibit thrashing where tasks are repeatedly moved between locations due to incomplete global load information. This paper shows that systems of autonomous mobile programs (AMPs) exhibit the same behaviour, and identifies two types of redundant movement (greedy effect). AMPs are unusual in that, in place of some external load management system, each AMP periodically recalculates network and program parameters and may independently move to a better execution environment. Load management emerges from the behaviour of collections of AMPs.</p> <p>The paper explores the extent of greedy effects by simulating collections of AMPs and proposes negotiating AMPs (NAMPs) to ameliorate the problem. We present the design of AMPs with a competitive negotiation scheme (cNAMPs), and compare their performance with AMPs by simulation. We establish new properties of balanced networks of AMPs, and use these to provide a theoretical analysis of greedy effects.</p&gt

Colpotomy in total laparoscopic hysterectomy without using an energy source: a new approach

Structured Abstract : At present, energy source is used, either monopolar current or harmonic scalpel in total laparoscopic hysterectomy for colpotomy. This is associated with lateral thermal damage to adjacent organs. The risk of scar dehiscence is high as compared to abdominal hysterectomy The objective of the new technique is to reduce these complications. The colpotomy is done by blade and scissors through the vaginal tube and not by any energy source. The cut edge is sharp making it easy to pick full thickness. Colpotomy is quicker than by using energy source, there are no toxic fumes thus visibility is not affected. Cardinal ligaments are tied to edge of vaginal angle, as is done in abdominal hysterectomy. Key words: colpotomy, energy source, laparoscopic hysterectomy, ureteral injur

Colpotomy in total laparoscopic hysterectomy without using an energy source: a new approach

Structured Abstract : At present, energy source is used, either monopolar current or harmonic scalpel in total laparoscopic hysterectomy for colpotomy. This is associated with lateral thermal damage to adjacent organs. The risk of scar dehiscence is high as compared to abdominal hysterectomy The objective of the new technique is to reduce these complications. The colpotomy is done by blade and scissors through the vaginal tube and not by any energy source. The cut edge is sharp making it easy to pick full thickness. Colpotomy is quicker than by using energy source, there are no toxic fumes thus visibility is not affected. Cardinal ligaments are tied to edge of vaginal angle, as is done in abdominal hysterectomy. Key words: colpotomy, energy source, laparoscopic hysterectomy, ureteral injur

Stitching Dynamic Movement Primitives and Image-based Visual Servo Control

Utilizing perception for feedback control in combination with Dynamic Movement Primitive (DMP)-based motion generation for a robot's end-effector control is a useful solution for many robotic manufacturing tasks. For instance, while performing an insertion task when the hole or the recipient part is not visible in the eye-in-hand camera, a learning-based movement primitive method can be used to generate the end-effector path. Once the recipient part is in the field of view (FOV), Image-based Visual Servo (IBVS) can be used to control the motion of the robot. Inspired by such applications, this paper presents a generalized control scheme that switches between motion generation using DMPs and IBVS control. To facilitate the design, a common state space representation for the DMP and the IBVS systems is first established. Stability analysis of the switched system using multiple Lyapunov functions shows that the state trajectories converge to a bound asymptotically. The developed method is validated by two real world experiments using the eye-in-hand configuration on a Baxter research robot.Comment: This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessibl

PERFORMANCE OF ULTRA-THIN WHITETOPPING (UTW) IN OKLAHOMA

With the current level of deterioration of pavements in Oklahoma and the United States a satisfactory repair technique that is economical and can be applied rapidly while resisting a significant volume of traffic is becoming important. Thin concrete overlays have been used in increasing numbers over hot-mix asphalt (HMA) pavements and at intersections as a rapid and economical method of repair. These repairs have shown outstanding service in the state of Oklahoma with service lives over 10 years when used in areas with moderate truck traffic. These overlays are commonly referred to as white toppings as the overlay material is much lighter than the asphalt it is overlaying. This report is organized in three major sections. In section 2 the current condition of whitetopping projects is reviewed in Oklahoma. The inspection of these projects was primarily done with visual inspection, but some work was done with cores from the projects and also with Falling Weight Deflectrometer (FWD) measurements. In section 3 a review of the different whitetopping design methodologies is presented. In section 4 specific unanswered questions over whitetoppings are covered that the Oklahoma DOT felt were important to address from the existing literature.Final Report, October 2009-December 2010N

Safe Adaptive Trajectory Tracking Control of Robot for Human-Robot Interaction Using Barrier Function Transformation

In this chapter, safety methods in human-robot (HR) interaction/collaboration are presented. Ensuring the safety of humans, objects, or even the robot itself in the robot’s operating environment is one of the crucial aspects of collaborative robotics. Since there are limited ways of controlling the behavior of humans, e.g., by placing physical barriers, shaping the behavior of the robot is a feasible option. The chapter discusses current methods of placing barriers for human safety in an industrial setting and novel methods of placing virtual barriers by designing robot controllers using barrier transformation. The concepts of barrier functions (BFs), control barrier functions (CBFs), and barrier transformations are reviewed. The barrier transformation concept is used to design an adaptive trajectory tracking controller for the robot such that the robot does not cross the virtual barriers. The designed controller is tested in simulations. Future directions of safety technology in human-robot collaboration are presented