scholarly journals Motion and Trajectory Constraints Control Modeling for Flexible Surgical Robotic Systems

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 386
Author(s):  
Olatunji Mumini Omisore ◽  
Shipeng Han ◽  
Yousef Al-Handarish ◽  
Wenjing Du ◽  
Wenke Duan ◽  
...  
Keyword(s):  
Real Time ◽  
A Priori ◽  
Tumor Resection ◽  
Computational Effort ◽  
Robotic Systems ◽  
Kinematics And Dynamics ◽  
Target Point ◽  
Real Time Control ◽  
Control Models ◽  
Constraints Model

Success of the da Vinci surgical robot in the last decade has motivated the development of flexible access robots to assist clinical experts during single-port interventions of core intrabody organs. Prototypes of flexible robots have been proposed to enhance surgical tasks, such as suturing, tumor resection, and radiosurgery in human abdominal areas; nonetheless, precise constraint control models are still needed for flexible pathway navigation. In this paper, the design of a flexible snake-like robot is presented, along with the constraints model that was proposed for kinematics and dynamics control, motion trajectory planning, and obstacle avoidance during motion. Simulation of the robot and implementation of the proposed control models were done in Matlab. Several points on different circular paths were used for evaluation, and the results obtained show the model had a mean kinematic error of 0.37 ± 0.36 mm with very fast kinematics and dynamics resolution times. Furthermore, the robot’s movement was geometrically and parametrically continuous for three different trajectory cases on a circular pathway. In addition, procedures for dynamic constraint and obstacle collision detection were also proposed and validated. In the latter, a collision-avoidance scheme was kept optimal by keeping a safe distance between the robot’s links and obstacles in the workspace. Analyses of the results showed the control system was optimal in determining the necessary joint angles to reach a given target point, and motion profiles with a smooth trajectory was guaranteed, while collision with obstacles were detected a priori and avoided in close to real-time. Furthermore, the complexity and computational effort of the algorithmic models were negligibly small. Thus, the model can be used to enhance the real-time control of flexible robotic systems.

scholarly journals XBot: A Cross-Robot Software Framework for Real-Time Control

2021 ◽  
Author(s):  
Luca Muratore ◽  
Arturo Laurenzi ◽  
Nikos G. Tsagarakis
Keyword(s):  
Software Architecture ◽  
Real Time ◽  
Humanoid Robots ◽  
Robotic Systems ◽  
Real Time Control ◽  
Software Infrastructure ◽  
Robotic Arms ◽  
Time Control ◽  
Control Frequency ◽  
High Control

The widespread use of robotics in new application domains outside the industrial workplace settings requires robotic systems which demonstrate functionalities far beyond that of classical industrial robotic machines. The implementation of these capabilities inevitably increases the complexity of the robotic hardware, control a and software components. This chapter introduces the XBot software architecture for robotics, which is capable of Real-Time (RT) performance with minimum jitter at relatively high control frequency while demonstrating enhanced flexibility and abstraction features making it suitable for the control of robotic systems of diverse hardware embodiment and complexity. A key feature of the XBot is its cross-robot compatibility, which makes possible the use of the framework on different robots, without code modifications, based only on a set of configuration files. The design of the framework ensures easy interoperability and built-in integration with other existing software tools for robotics, such as ROS, YARP or OROCOS, thanks to a robot agnostic API called XBotInterface. The framework has been successfully used and validated as a software infrastructure for collaborative robotic arms as KUKA lbr iiwa/lwr 4+ and Franka Emika Panda, other than humanoid robots such as WALK-MAN and COMAN+, and quadruped centaur-like robots as CENTAURO.

Modeling and Simulation of Discrete Event Robotic Systems Using Extended Petri Nets

2012 ◽  
pp. 51-69
Author(s):  
Gen’ichi Yasuda
Keyword(s):  
Petri Nets ◽  
Real Time ◽  
Discrete Event ◽  
Control Flow ◽  
Coordination Mechanism ◽  
Robotic Systems ◽  
Real Time Control ◽  
Time Control ◽  
Extended Petri Nets ◽  
Implementation Problems

This chapter deals with modeling, simulation, and implementation problems encountered in robotic manufacturing control systems. Extended Petri nets are adopted as a prototyping tool for expressing real-time control of robotic systems and a systematic method based on hierarchical Petri nets is described for their direct implementation. A coordination mechanism is introduced to coordinate the event activities of the distributed machine controllers through friability tests of shared global transitions. The proposed prototyping method allows a direct coding of the inter-task cooperation by robots and intelligent machines from the conceptual Petri net specification, so that it increases the traceability and the understanding of the control flow of a parallel application specified by a net model. This approach can be integrated with off-the-shelf real-time executives. Control software using multithreaded programming is demonstrated to show the effectiveness of the proposed method.

An Efficient Static Analysis of Continuum Robots

2014 ◽  
Vol 6 (3) ◽  
Author(s):  
Shahir Hasanzadeh ◽  
Farrokh Janabi-Sharifi
Keyword(s):  
Real Time ◽  
Recursive Algorithm ◽  
A Priori ◽  
Real Time Control ◽  
Equilibrium Equations ◽  
Backbone Curve ◽  
Time Control ◽  
Continuum Robot ◽  
Main Component ◽  
The Continuum

An efficient yet accurate model of the continuum robot is the main component for its real-time control, simulation as well as localization. Previous models of the continuum robot, based on rod theory, suffer from high computational burden. The models also require a priori knowledge of the robot environment. This paper presents an efficient static model for the planar continuum robot that experiences external forces at the tip as a result of contact with its surroundings (measured by the built-in force sensors), thus no a priori information about the environment is required. The typical example of such robots is steerable catheters used in medical operations. The proposed approach involves discretizing the robot backbone curve to elastic arc elements. After deriving the equilibrium equations for the infinitesimal elements, a recursive algorithm with the time complexity of O(n) is proposed for realizing the shape of the robot as a result of the external force. Accuracy of the proposed method is evaluated both theoretically and experimentally for a case study, i.e., an intracardiac ablation catheter. Results validate the accuracy and time-efficiency of the proposed approach for real-time applications.

A programming environment for real-time control of distributed multiple robotic systems

2000 ◽  
Vol 14 (1) ◽  
pp. 75-86 ◽  
Author(s):  
Maurizio Piaggio ◽  
Antonio Sgorbissa ◽  
Renato Zaccaria
Keyword(s):  
Real Time ◽  
Robotic Systems ◽  
Programming Environment ◽  
Real Time Control ◽  
Time Control

Validation of a Novel In-Vitro Simulator for Real-Time Control of Active Shoulder Movements in Various Planes of Motion

2013 ◽  
Author(s):  
J. W. Giles ◽  
L. M. Ferreira ◽  
G. S. Athwal ◽  
J. A. Johnson
Keyword(s):  
Real Time ◽  
Degrees Of Freedom ◽  
A Priori ◽  
Axial Rotation ◽  
Open Loop ◽  
Abduction Angle ◽  
Real Time Control ◽  
Loop Control ◽  
Shoulder Motion

In-vitro simulation of active shoulder joint motion is critical to gaining an understanding of the effects of surgical procedures and implant designs. However, development of systems for the accurate simulation of active shoulder motion has lagged well behind those implemented for the lower limb and elbow, which have used principles of closed-loop joint angle control 1,4. In contrast, active shoulder motion has been confined to simulators that can hold static joint angles through the application of loads based on computer model outputs 2, or that use constant velocity of the middle deltoid while using open-loop control to apportion other muscle loads as a function of a-priori physiologic loading ratios 3. Neither of these schemes utilizes real-time feedback of kinematic data in order to follow smooth, predefined profiles. The lack of more refined shoulder simulators, based on control theory, can primarily be attributed to the complexity of shoulder motion and the number of degrees of freedom (DOFs) ( i.e. plane of abduction, abduction angle, and axial rotation) which must be controlled.

An Artificial Intelligence Approach to Real Time control of carbonization

1988 ◽  
Vol 117 ◽  
Author(s):  
William J. Pardee ◽  
Kwang Chung ◽  
Ming Shong Lan
Keyword(s):  
Real Time ◽  
Material Properties ◽  
Expert Knowledge ◽  
A Priori ◽  
Gas Analysis ◽  
Real Time Control ◽  
Time Model ◽  
Time Control ◽  
Physical Changes ◽  
Physical And Chemical

Carbonization of carbon-carbon composites is presently a slow, costly process. The failure rate and the variation in final material properties are both excessive. The complex physical and chemical changes require new control methods. Real time sensing of material properties can, in combination with a priori expert knowledge, be used to improve real time model estimates of process outcome and to revise the process. The basic elements of the control strategy for real time control of carbonization based on thermal, acoustic, conductivity, and gas chemistry sensors are described. Preliminary results relate real time gas analysis to physical changes.

Modeling and Simulation of Discrete Event Robotic Systems Using Extended Petri Nets

2012 ◽  
pp. 577-593
Author(s):  
Gen’ichi Yasuda
Keyword(s):  
Petri Nets ◽  
Real Time ◽  
Discrete Event ◽  
Control Flow ◽  
Coordination Mechanism ◽  
Robotic Systems ◽  
Real Time Control ◽  
Time Control ◽  
Extended Petri Nets ◽  
Implementation Problems

This chapter deals with modeling, simulation, and implementation problems encountered in robotic manufacturing control systems. Extended Petri nets are adopted as a prototyping tool for expressing real-time control of robotic systems and a systematic method based on hierarchical Petri nets is described for their direct implementation. A coordination mechanism is introduced to coordinate the event activities of the distributed machine controllers through friability tests of shared global transitions. The proposed prototyping method allows a direct coding of the inter-task cooperation by robots and intelligent machines from the conceptual Petri net specification, so that it increases the traceability and the understanding of the control flow of a parallel application specified by a net model. This approach can be integrated with off-the-shelf real-time executives. Control software using multithreaded programming is demonstrated to show the effectiveness of the proposed method.

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