A Unified Approach for Multi-Point Cartesian Compliance Control of Serial Manipulators

2010 ◽  
Author(s):  
Phongsaen Pitakwatchara
Keyword(s):  
Generalized Inverse ◽  
Impedance Control ◽  
Level Control ◽  
Unified Approach ◽  
Relative Priority ◽  
Multiple Points ◽  
Serial Manipulators ◽  
Control Scheme ◽  
Planning Algorithm ◽  
High Level

This paper proposes a unified approach for controlling the Cartesian compliance of multiple points assigned along the linkage chains of the manipulator. The method applies two key frameworks. Task-priority based control is used to synergistically plan the tasks of the advanced manipulation according to their relative priority. Then, the impedance control scheme is employed for implementing the controller. Additionally, with the use of generalized inverse theory throughout the development, the method is capable of controlling the manipulator at the singularities seamlessly. This low-level control system may be integrated with the high-level manipulation planning algorithm, which generates the online dynamical tasks based on the desired behavior and the sensor information, to accomplish the demanding operation.

A Model of Caterpillar Locomotion Based on Assur Tensegrity Structures

2011 ◽  
Author(s):  
Omer Orki ◽  
Offer Shai ◽  
Amir Ayali ◽  
Uri Ben-Hanan
Keyword(s):  
Hydrostatic Pressure ◽  
Control Algorithm ◽  
Control Unit ◽  
Engineering Properties ◽  
Level Control ◽  
Tensegrity Structures ◽  
Control Scheme ◽  
High Level ◽  
Longitudinal Muscles ◽  
Ongoing Project

This paper presents an ongoing project aiming at building a robot composed of Assur tensegrity structures, which mimics caterpillar locomotion. Caterpillars are soft-bodied animals capable of making complex movements with astonishing fault-tolerance. In our model, each caterpillar segment is represented by a 2D tensegrity triad consisting of two bars connected by two cables and a strut. The cables represent the major longitudinal muscles of the caterpillar, while the strut represents hydrostatic pressure. The control scheme in this model is divided into localized low-level controllers and a high-level control unit. The unique engineering properties of Assur tensegrity structures, which were mathematically proved last year, together with the suggested control algorithm provide the model with robotic softness. Moreover, the degree of softness can be continuously changed during simulation, making this model suitable for simulation of soft-bodied caterpillars as well as other types of soft animals.

scholarly journals Multi-Objective Supervisory Control for DC/DC Converters in Advanced Aeronautic Applications

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3216 ◽  
Author(s):  
Alberto Cavallo ◽  
Giacomo Canciello ◽  
Beniamino Guida ◽  
Ponggorn Kulsangcharoen ◽  
Seang Yeoh ◽  
...  
Keyword(s):  
Low Voltage ◽  
Control Strategies ◽  
Gain Control ◽  
High Gain ◽  
Level Control ◽  
Mathematical Arguments ◽  
Control Scheme ◽  
Sliding Manifold ◽  
High Gain Control ◽  
High Level

In this paper, an intelligent control strategy for DC/DC converters is proposed. The converter connects two DC busses, a high-voltage and a low-voltage bus. The control scheme is composed by a two-layer architecture, a low-level control based on the concept of sliding manifold, and high gain control, and a high-level control used to guarantee the achievement of various objectives. The proposed control strategies are based on solid mathematical arguments, with stability proofs for the non-linear case, and decision trees for parameter selection. The paper results are analyzed and discussed by using simulation at different detail levels in MATLAB/Stateflow/PowerSystem, and validated by experimental results, also considering MIL standard performance indices.

scholarly journals Visual-Based SLAM Configurations for Cooperative Multi-UAV Systems with a Lead Agent: An Observability-Based Approach

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4243 ◽  
Author(s):  
Juan-Carlos Trujillo ◽  
Rodrigo Munguia ◽  
Edmundo Guerra ◽  
Antoni Grau
Keyword(s):  
Fundamental Problem ◽  
Position Estimation ◽  
Level Control ◽  
Aerial Robots ◽  
Control Scheme ◽  
High Level ◽  
System Configurations ◽  
Theoretical Results ◽  
Multi Uav ◽  
Nonlinear Observability

In this work, the problem of the cooperative visual-based SLAM for the class of multi-UA systems that integrates a lead agent has been addressed. In these kinds of systems, a team of aerial robots flying in formation must follow a dynamic lead agent, which can be another aerial robot, vehicle or even a human. A fundamental problem that must be addressed for these kinds of systems has to do with the estimation of the states of the aerial robots as well as the state of the lead agent. In this work, the use of a cooperative visual-based SLAM approach is studied in order to solve the above problem. In this case, three different system configurations are proposed and investigated by means of an intensive nonlinear observability analysis. In addition, a high-level control scheme is proposed that allows to control the formation of the UAVs with respect to the lead agent. In this work, several theoretical results are obtained, together with an extensive set of computer simulations which are presented in order to numerically validate the proposal and to show that it can perform well under different circumstances (e.g., GPS-challenging environments). That is, the proposed method is able to operate robustly under many conditions providing a good position estimation of the aerial vehicles and the lead agent as well.

Development of an autonomous robotic system for beard shaving assistance of disabled people based on an adaptive force tracking impedance control

2021 ◽  
pp. 095440622098482
Author(s):  
Oladayo S Ajani ◽  
Samy FM Assal
Keyword(s):  
Impedance Control ◽  
Environmental Parameters ◽  
Robotic System ◽  
Robotic Systems ◽  
Full Potential ◽  
Robotic Assistance ◽  
Head Pose ◽  
Detection And Tracking ◽  
Control Scheme ◽  
Force Tracking

Recently, people with upper arm disabilities due to neurological disorders, stroke or old age are receiving robotic assistance to perform several activities such as shaving, eating, brushing and drinking. Although the full potential of robotic assistance lies in the use of fully autonomous robotic systems, these systems are limited in design due to the complexities and the associated risks. Hence, rather than the shared controlled or active robotic systems used for such tasks around the head, an adaptive compliance control scheme-based autonomous robotic system for beard shaving assistance is proposed. The system includes an autonomous online face detection and tracking as well as selected geometrical features-based beard region estimation using the Kinect RGB-D camera. Online trajectory planning for achieving the shaving task is enabled; with the capability of online re-planning trajectories in case of unintended head pose movement and occlusion. Based on the dynamics of the UR-10 6-DOF manipulator using ADAMS and MATLAB, an adaptive force tracking impedance controller whose parameters are tuned using Genetic Algorithm (GA) with force/torque constraints is developed. This controller can regulate the contact force under head pose changing and varying shaving region stiffness by adjusting the target stiffness of the controller. Simulation results demonstrate the system capability to achieve beard shaving autonomously with varying environmental parameters that can be extended for achieving other tasks around the head such as feeding, drinking and brushing.

scholarly journals Bi-level Control Scheme for Vehicle-to-Grid Regulation Services

2012 ◽  
Vol 5 (2) ◽  
pp. 430-446
Author(s):  
Shuang. Gao ◽  
K. Chau ◽  
C. Chan ◽  
Chunhua Liu
Keyword(s):  
Level Control ◽  
Vehicle To Grid ◽  
Control Scheme ◽  
Regulation Services

An Islanding Microgrid Power Sharing Approach Using Enhanced Virtual Impedance Control Scheme

2013 ◽  
Vol 28 (11) ◽  
pp. 5272-5282 ◽  
Author(s):  
Jinwei He ◽  
Yun Wei Li ◽  
Josep M. Guerrero ◽  
Frede Blaabjerg ◽  
Juan C. Vasquez
Keyword(s):  
Impedance Control ◽  
Power Sharing ◽  
Control Scheme ◽  
Virtual Impedance

scholarly journals Simulations and experimental evaluation of an active orthosis for interaction in virtual environments

2018 ◽  
Vol 145 ◽  
pp. 01006
Author(s):  
Mihail Tsveov ◽  
Pavel Venev ◽  
Dimitar Chakarov ◽  
Ivanka Veneva
Keyword(s):  
Virtual Environments ◽  
Impedance Control ◽  
Computer Experiments ◽  
Open Loop ◽  
Body Parts ◽  
Human Arm ◽  
Control Scheme ◽  
Force Reflection ◽  
Physical Quantities ◽  
Active Orthosis

In this work, the development of a human arm active orthosis is presented. The orthosis is designed primarily for training and rehabilitation in virtual environments.The orthosis system is intended for embodiment in virtual reality where it is allowing human to perceive forces at different body parts or the weight of lifted objects. In the paper the choice of a mechanical structure is shown equivalent to the structure of the human arm. A mechanical model of the orthosis arm as haptic device is built, where kinematic and dynamic parameters are evaluated. Impedance control scheme is selected as the most suitable for force refection at the hand or arm. An open-loop impedance controller is presented in the paper. Computer experiments are carried out using the dimensions of a real arm orthosis. Computer experiments have been carried out to provide force reflection by VR, according to virtual scenario. The conducted simulations show the range of the forces on the operator hand, orthosis can provide. The results of additional measurements and experimental evaluations of physical quantities in the interaction in a virtual environment are revealed in the paper.

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