Complete Accessibility of Oscillations in Robotic Systems by Orthogonal Projections

1990 ◽  
Vol 112 (2) ◽  
pp. 194-202 ◽  
Author(s):  
Sabri Tosunoglu ◽  
Shyng-Her Lin ◽  
Delbert Tesar
Keyword(s):  
Current Practice ◽  
Industrial Robot ◽  
Robotic Systems ◽  
Orthogonal Projections ◽  
Small Oscillations ◽  
Robotic Arms ◽  
Driven System ◽  
System Equations ◽  
Six Degree Of Freedom

The current practice of controller development for flexible robotic systems generally focuses on one-link robotic arms and is valid for small oscillations. This work addresses the control of n-link, serial, spatial robotic systems modeled with m1 joint and m2 link flexibilities such that n≥m1+m2. System compliance is modeled by local springs and nonactuated prismatic and revolute type pseudo joints. The coupled, nonlinear, error-driven system equations are derived for the complete model without linearization or neglecting certain terms. For this system, the complete accessibility of vibrations is studied by orthogonal projections. It is shown that under some configurations of a robotic system, the induced oscillations may not be accessible to the controller. Given accessibility, the controller developed in this work assures the global asymptotic stability of the system. Example numerical simulations are presented based on the model of a six-degree-of-freedom Cincinnati Milacron T3-776 industrial robot. One example models the system compliance in four joints, while another case study simulates four lateral link oscillations. These examples show that this controller, even under inaccurate payload description, eliminates the oscillations while tracking desired trajectories.

Time suboptimal control of industrial manipulators along specified paths while keeping an end-effector orientation unchanged

Robotica ◽  
2003 ◽  
Vol 21 (2) ◽  
pp. 153-161 ◽  
Author(s):  
S. Kilicaslan ◽  
Y. Ercan
Keyword(s):  
Suboptimal Control ◽  
Time Step ◽  
End Effector ◽  
Industrial Manipulator ◽  
Industrial Manipulators ◽  
Angular Velocities ◽  
System Equations ◽  
Six Degree Of Freedom ◽  
Time Suboptimal Control

A method for the time suboptimal control of an industrial manipulator that moves along a specified path while keeping its end-effector orientation unchanged is proposed. Nonlinear system equations that describe the manipulator motion are linearized at each time step along the path. A method which gives control inputs (joint angular velocities) for time suboptimal control of the manipulator is developed. In the formulation, joint angular velocity and acceleration limitations are also taken into consideration. A six degree of freedom elbow type manipulator is used in a case study to verify the method developed.

A systematic procedure for the identification of dynamic parameters of robot manipulators

Robotica ◽  
1999 ◽  
Vol 17 (4) ◽  
pp. 427-435 ◽  
Author(s):  
G. Antonelli ◽  
F. Caccavale ◽  
P. Chiacchio
Keyword(s):  
Robot Manipulators ◽  
Industrial Robot ◽  
Chain Structure ◽  
Practical Case ◽  
Dynamic Parameters ◽  
Open Chain ◽  
Systematic Procedure ◽  
A New Technique ◽  
Six Degree Of Freedom

In this paper a complete and systematic procedure for the identification of the dynamic parameters of rigid robot manipulators is presented. Starting from the basic results on the subject present in the literature and on a new technique to find exciting trajectories for the estimation, the procedure is developed. A set of algorithms is provided for the implementation of the various steps of the procedure for a generic open-chain structure. The algorithms have been coded in the popular Matlab/Maple environment and the procedure has been tested in a practical case study to identify the dynamic parameters of a six-degree-of-freedom conventional industrial robot.

Design of spline surface vacuum gripper for pick and place robotic arms

2020 ◽  
Vol 4 (2) ◽  
pp. 48-55
Author(s):  
A. S. Jamaludin ◽  
M. N. M. Razali ◽  
N. Jasman ◽  
A. N. A. Ghafar ◽  
M. A. Hadi
Keyword(s):  
Cycle Time ◽  
Industrial Robot ◽  
Annealing Process ◽  
Vacuum Suction ◽  
Robotic Arms ◽  
Custom Made ◽  
Pick And Place ◽  
Manufacturing Procedure ◽  
Production Flexibility ◽  
The Impact

The gripper is the most important part in an industrial robot. It is related with the environment around the robot. Today, the industrial robot grippers have to be tuned and custom made for each application by engineers, by searching to get the desired repeatability and behaviour. Vacuum suction is one of the grippers in Watch Case Press Production (WCPP) and a mechanism to improve the efficiency of the manufacturing procedure. Pick and place are the important process for the annealing process. Thus, by implementing vacuum suction gripper, the process of pick and place can be improved. The purpose of vacuum gripper other than design vacuum suction mechanism is to compare the effectiveness of vacuum suction gripper with the conventional pick and place gripper. Vacuum suction gripper is a mechanism to transport part and which later sequencing, eliminating and reducing the activities required to complete the process. Throughout this study, the process pick and place became more effective, the impact on the production of annealing process is faster. The vacuum suction gripper can pick all part at the production which will lower the loss of the productivity. In conclusion, vacuum suction gripper reduces the cycle time about 20%. Vacuum suction gripper can help lower the cycle time of a machine and allow more frequent process in order to increase the production flexibility.

The Pransky interview: Dr Nabil Simaan, Vanderbilt University Professor of Mechanical Engineering, Computer Science and Otolaryngology, Thought Leader in Medical Robotics

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Joanne Pransky
Keyword(s):  
Computer Science ◽  
Mechanical Engineering ◽  
Single Port ◽  
Industrial Robot ◽  
Medical Robotics ◽  
Surgical Robotics ◽  
Robotic Systems ◽  
Content Type ◽  
Thought Leader ◽  
Vanderbilt University

Purpose The following article is a “Q&A interview” conducted by Joanne Pransky of Industrial Robot Journal as a method to impart the combined technological, business and personal experience of a prominent, robotic industry PhD and innovator regarding his pioneering efforts. The paper aims to discuss these issues. Design/methodology/approach The interviewee is Dr Nabil Simaan, Professor of Mechanical Engineering, Computer Science and Otolaryngology at Vanderbilt University. He is also director of Vanderbilt’s Advanced Robotics and Mechanism Applications Research Laboratory. In this interview, Simaan shares his unique perspective and approaches on his journey of trying to solve real-world problems in the medical robotics area. Findings Simaan received his BSc, MSc and PhD in mechanical engineering from the Technion – Israel Institute of Technology. He served as Postdoctoral Research Scientist in Computer Science at Johns Hopkins University. In 2005, he joined Columbia University, New York, NY, as an Assistant Professor of Mechanical Engineering until 2010, when he joined Vanderbilt. His current applied research interests include synthesis of novel robotic systems for surgical assistance in confined spaces with applications to minimally invasive surgery of the throat, natural orifice surgery, cochlear implant surgery and dexterous bimanual microsurgery. Theoretical aspects of his research include robot design and kinematics. Originality/value Dr Simaan is a leading pioneer on designing robotic systems and mechanisms for medical applications. Examples include technologies for snake robots licensed to Intuitive Surgical; technologies for micro-surgery of the retina, which led to the formation of AURIS Surgical Robotics; the insertable robotic effector platform (IREP) single-port surgery robot that served as the research prototype behind the Titan Medical Inc. Sport (Single Port Orifice Robotic Technology). Simaan received the NSF Career award for young investigators to design new algorithms and robots for safe interaction with the anatomy. He has served as the Editor for IEEE International Conference on Robotics and Automation, Associate Editor for IEEE Transactions on Robotics, Editorial Board Member of Robotica, Area Chair for Robotics Science and Systems and corresponding Co-chair for the IEEE Technical Committee on Surgical Robotics. In January 2020, he was bestowed the award of Institute of Electrical and Electronics Engineers (IEEE) Fellow for Robotics Advancements. At the end of 2020, he was named a top voice in health-care robotics by technology discovery platform InsightMonk and market intelligence firm BIS Research. Simaan holds 15 patents. A producer of human capital, his education goal is to achieve the best possible outcome with every student he works with.

scholarly journals Interpreting Traditional Cost Contingency Methods in the Construction Industry

2021 ◽  
Author(s):  
Michael Donn ◽  
Alexis Dykman ◽  
Nilesh Bakshi
Keyword(s):  
Construction Industry ◽  
Construction Projects ◽  
Reliable Method ◽  
Current Practice ◽  
Simulation Method ◽  
Future Research ◽  
Building Industry ◽  
Simulation Methods ◽  
Journal Paper

This research investigates how contingency is currently calculated in project budgets within the building industry. This is an important aspect to consider as a large proportion of construction projects are significantly over-budget. The study presents three non-simulation methods and one simulation method for calculating cost contingency following the results of a forthcoming journal paper. These methods are applied against a case study project in attempt to highlight the most reliable method, and to create a methodology that will be useful to the industry. This paper identifies that the traditional fixed percentage approach is not sufficient and suggests that this could be one of the main reasons why construction projects are over budget. While it is unclear which method is the most reliable, this study provides a focus for future research into reliability and utilisation of contingency methods in the building industry. The research demonstrates that current practice needs to change to reduce the large number of construction projects that run over budget.

Comparison of under-actuated and fully-actuated serial robotic arms: a case study

2021 ◽  
pp. 1-13
Author(s):  
Matteo Bottin ◽  
Giulio Rosati
Keyword(s):  
Degrees Of Freedom ◽  
Simple Point ◽  
Controllable System ◽  
Robotic Arms ◽  
Passive Joint ◽  
Final Configuration ◽  
Vibration Behavior ◽  
Rotational Joint ◽  
Point To Point

Abstract Under-actuated robots are very interesting in terms of cost and weight since they can result in a state-controllable system with a number of actuators lower than the number of joints. In this paper, a comparison between an under-actuated planar 3 degrees of freedom (DOF) robot and a comparable fully-actuated 2 degrees of freedom robot is presented, mainly focusing on the performances in terms of trajectories, actuator torques, and vibrations. The under-actuated system is composed of 2 active rotational joints followed by a passive rotational joint equipped with a torsional spring. The fully-actuated robot is inertial equivalent to the under-actuated manipulator: the last link is equal to the sum of the last two links of the under-actuated system. Due to the conditions on the inertia distribution and spring placement, in a simple point-to-point movement the last passive joint starts and ends in a zero-value configuration, so the 3 DOF robot is equivalent, in terms of initial and final configuration, to the 2 DOF fully-actuated robot, thus they can be compared. Results show how while the fully actuated robot is better in terms of reliable trajectory and actuator torques, the under-actuated robot wins in flexibility and vibration behavior.

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