Modeling and Control of Four-bar Mechanism with Series Elastic Actuators

2020 ◽  
Author(s):  
Felipe R. Lopes ◽  
Marco A. Meggiolaro
Keyword(s):  
Human Interaction ◽  
Robotic Manipulation ◽  
Modeling And Control ◽  
Lqr Control ◽  
In Series ◽  
Flexible Behavior ◽  
Series Elastic Actuators ◽  
New Generation ◽  
And Control ◽  
Series Elastic

A new generation of robots that work in cooperation with humans (called collaborative robots) needs some flexibility to adapt to the environment and activities with people. That is why the Series Elastic Actuator (SEA) has been a breakthrough in actuator technologies. The idea of inserting an elastic element in series with a motor allows a lower output impedance, consequently a flexible behavior in the manipulator, in addition to providing torque feedback to better compensate disturbances caused e.g. by friction losses. This article presents a four-bar mechanism with SEA for the purpose of robotic manipulation. Its kinematics and dynamicsare studied, as well as its regulation and trajectory control. The behavior of the decoupled four-bar mechanism and the characteristics of the SEA are also analyzed. Then the regulation control of the complete system is carried out using LQR control. Finally, a circular trajectory is controlled in a simulation to validate the proposed control strategy. The simulation results show the effectiveness of the proposed controller for the mechanism in the presence of SEAs estimating torque and providing the desired compliance for human interaction.

Modeling and Control of Nonlinear Series Elastic Actuator

2007 ◽  
Author(s):  
Ehsan Basafa ◽  
Hassan Salarieh ◽  
Aria Alasty
Keyword(s):  
Nonlinear Models ◽  
Human Gait ◽  
Output Impedance ◽  
Modeling And Control ◽  
Series Elastic Actuator ◽  
Scheduling Method ◽  
Normal Human ◽  
Series Elastic Actuators ◽  
And Control ◽  
Series Elastic

Series Elastic Actuators are force actuators with applications in robotics and biomechanics. In linear Series Elastic Actuators, a large force bandwidth requires a stiff sensor (spring), but the output impedance puts an upper limit on this parameter, therefore selecting the proper spring is difficult in these actuators. In this paper, Series Elastic Actuator is modeled with a nonlinear, stiffening spring and controlled using the Gain Scheduling method. Simulations show that both linear and nonlinear models have similar force bandwidths, but the nonlinear one shows much lower output impedance. Hence, the choice of spring for actuator design is an easier task than that of the linear model. Also, as a force-augmenting device for the knee joint in normal human gait, the nonlinear model acts better in simulations.

scholarly journals Design, Modelling and Control of Novel Series-Elastic Actuators for Industrial Robots

Actuators ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 6 ◽  
Author(s):  
José de Gea Fernández ◽  
Bingbin Yu ◽  
Vinzenz Bargsten ◽  
Michael Zipper ◽  
Holger Sprengel
Keyword(s):  
Industrial Robots ◽  
Data Driven ◽  
User Needs ◽  
End User ◽  
Different Types ◽  
Series Elastic Actuators ◽  
And Control ◽  
Collaborative Robot ◽  
Modelling Methods ◽  
Series Elastic

This paper describes data-driven modelling methods and their use for the control of a novel set of series-elastic actuators (SEAs). A set of elastic actuators was developed in order to fulfill the end-user needs for tailored industrial collaborative robot manipulators of different morphologies and payloads. Three different types of elastic actuation were investigated, namely, disc springs, coil springs and torsion bars. The developed algorithms were validated both on single actuators and on a 6-DOF robotic arm composed of such actuators.

Modeling and control of biologically inspired flying robots

Robotica ◽  
2011 ◽  
Vol 30 (1) ◽  
pp. 107-121 ◽  
Author(s):  
Micael S. Couceiro ◽  
J. Miguel A. Luz ◽  
Carlos M. Figueiredo ◽  
N. M. Fonseca Ferreira
Keyword(s):  
Dynamic Models ◽  
Dynamic Control ◽  
Biologically Inspired ◽  
Modeling And Control ◽  
High Level ◽  
New Generation ◽  
And Control ◽  
Level Calculation ◽  
Potential Use ◽  
Flying Robots

SUMMARYThis paper covers a wide knowledge of physical and dynamical models useful for building flying robots and a new generation of flying platform developed in the similarity of flying animals. The goal of this work is to develop a simulation environment and dynamic control using the high-level calculation tool MatLab and the modeling, simulation, and analysis of dynamic systems tool Simulink. Once created the dynamic models to study, this work involves the study and understanding of the dynamic stability criteria to be adopted and their potential use in the control of flying models.

scholarly journals Modeling and control of two five-phase induction machines connected in series powered by matrix converter

2021 ◽  
Vol 12 (2) ◽  
pp. 685
Author(s):  
Mohamed Nekkaz ◽  
Abdelkader Djahbar ◽  
Rachid Taleb
Keyword(s):  
Induction Machines ◽  
Matrix Converter ◽  
Drive System ◽  
Modeling And Control ◽  
Input Side ◽  
In Series ◽  
Decoupled Control ◽  
Simulation Results ◽  
Five Phases ◽  
And Control

The two five-phase Induction Motor (IM) drive system that is serially connected is available in literature. The power supply of such system is considered as a matrix converter (a direct AC to AC converter system) by three and five-phases outputs. The main benefit from the drive topology is the sinusoidal source as a side current with a controllable input side power factor. The decoupled control is achieved similarly to the inverter based drive system. In this paper; the decoupled control of two five-phase induction machines serially connected and powered by a five-phase matrix converter as well as analytical and simulation results are presented.

Effect of compliance location in series elastic actuators

Robotica ◽  
2013 ◽  
Vol 31 (8) ◽  
pp. 1313-1318 ◽  
Author(s):  
Jonathon W. Sensinger ◽  
Lawrence E. Burkart ◽  
Gill A. Pratt ◽  
Richard F. ff. Weir
Keyword(s):  
Gear Ratio ◽  
Large Gear ◽  
Class 1 ◽  
In Series ◽  
Ratio Dependent ◽  
Series Elastic Actuators ◽  
Series Elastic ◽  
Instrumentation Design

SUMMARYSeries elastic actuators have beneficial properties for some robot applications. Several recent implementations contain alternative placements of the compliant element to improve instrumentation design. We use a class 1 versus class 2 lever model and energy-port methods to demonstrate in this paper that these alternative placements should still be classified as series elastic actuators. We also note that the compliance of proximal series elastic actuators is reflected by an augmented gear ratio dependent on the nominal gear ratio, which is significant for small gear ratios and approaches unity for large gear ratios. This reflected compliance is shown to differ depending on the sign of the gear ratio. We demonstrate that although the reflected compliance is only marginally influenced by the magnitude of the gear ratio, there are several notable differences, particularly for small gear ratios.

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