Analysis and simulation of a new Cartesian cable-suspended robot

2009 ◽  
Vol 224 (8) ◽  
pp. 1717-1726 ◽  
Author(s):  
G Castelli ◽  
E Ottaviano ◽  
A González
Keyword(s):  
Numerical Simulation ◽  
Degrees Of Freedom ◽  
Robot Arm ◽  
Fixed Frame ◽  
Cartesian Space ◽  
Compliant Assembly ◽  
Moving Platform ◽  
Geometry Analysis ◽  
Three Degrees Of Freedom

In this article, a manipulator is presented belonging to the class of cable-suspended robots, for which the cable length variations are related by suitable functions in order to achieve specific kinematic characteristics. In particular, in this article, a Cartesian cable-suspended robot is proposed that has eight cables to have three degrees of freedom (DOF) in Cartesian space. The eight cables of the robot are arranged in parallel by pairs with identical length, with the aim of constraining the moving platform to keep a constant orientation with respect to the fixed frame. The robot can be used for selective compliant assembly robot arm (SCARA) motions (when an additional revolute actuated joint is placed on the moving platform) for a variety of applications in which a large workspace is required. In this article, a geometry analysis of the robot is presented together with a numerical simulation of the kinetostatics and dynamics to investigate the robot's performances in several operative conditions. Furthermore, a characterization of the position workspace regions is reported for this cable-suspended robot.

Underactuated Part Alignment System (UPAS) for Industrial Assembly Tasks

2011 ◽  
Author(s):  
Brian J. Slaboch ◽  
Philip Voglewede
Keyword(s):  
Degrees Of Freedom ◽  
Vertical Plane ◽  
Cost Effective ◽  
Robotic Assembly ◽  
Robot Arm ◽  
Planning Techniques ◽  
Alignment System ◽  
Compliant Assembly ◽  
Industrial Assembly ◽  
Assembly Tasks

This paper introduces the Underactuated Part Alignment System (UPAS) as a cost-effective and flexible approach to aligning parts in the vertical plane prior to an industrial robotic assembly task. The advantage of the UPAS is that it utilizes the degrees of freedom (DOFs) of a SCARA (Selective Compliant Assembly Robot Arm) type robot in conjunction with an external fixed post to achieve the desired part alignment. Three path planning techniques will be presented that can be used with the UPAS to achieve the proper part rotation.

scholarly journals Introducing the Theory of Bonds for Stewart Gough Platforms With Self-Motions1

2013 ◽  
Vol 6 (1) ◽  
Author(s):  
Georg Nawratil
Keyword(s):  
Degrees Of Freedom ◽  
Parallel Manipulators ◽  
Geometric Characterization ◽  
Basic Facts ◽  
Self Motion ◽  
Three Degrees Of Freedom

We transfer the basic idea of bonds, introduced by Hegedüs, Schicho, and Schröcker for overconstrained closed chains with rotational joints, to the theory of self-motions of parallel manipulators of Stewart Gough (SG) type. Moreover, we present some basic facts and results on bonds and demonstrate the potential of this theory on the basis of several examples. As a by-product we give a geometric characterization of all SG platforms with a pure translational self-motion and of all spherical three-degrees of freedom (DOF) RPR manipulators with self-motions.

Robust Trajectory Following Control of Robotic Systems

1985 ◽  
Vol 107 (4) ◽  
pp. 308-315 ◽  
Author(s):  
S. N. Singh ◽  
A. A. Schy
Keyword(s):  
Degrees Of Freedom ◽  
Digital Simulation ◽  
Robotic Systems ◽  
Control Law ◽  
Robot Arm ◽  
Control Laws ◽  
Payload Uncertainty ◽  
Trajectory Following ◽  
And Control ◽  
Three Degrees Of Freedom

Using an inversion approach we derive a control law for trajectory following of robotic systems. A servocompensator is used around the inner decoupled loop for robustness to uncertainty in the system. These results are applied to trajectory control of a three-degrees-of-freedom robot arm and control laws Cθ and CH for joint angle and position trajectory following, respectively, are derived. Digital simulation results are presented to show the rapid trajectory following capability of the controller in spite of payload uncertainty.

Fuzzy Predictive Control Using Particle Swarm Optimization: Application to SCARA Robot

2014 ◽  
Vol 527 ◽  
pp. 230-236
Author(s):  
Mohamed Laid Hadjili ◽  
Kamel Kara ◽  
Oussama Ait Sahed ◽  
Jamal Bouyanzar
Keyword(s):  
Particle Swarm Optimization ◽  
Predictive Control ◽  
Degrees Of Freedom ◽  
Particle Swarm ◽  
Fuzzy Model ◽  
Robot Arm ◽  
Swarm Optimization ◽  
Modified Particle Swarm Optimization ◽  
Compliant Assembly ◽  
Fuzzy Predictive Control

In this work a fuzzy model-based predictive control (FMPC) method that uses modified particle swarm optimization (PSO) is presented. The main objective of this work is the application of this method to the control of a Selective Compliant Assembly Robot Arm (SCARA) with four degrees of freedom (4-DOF).

Multibody Analysis and Design of a Reconfigurable Parallel Kinematics Manipulator

2015 ◽  
Author(s):  
Matteo Palpacelli ◽  
Massimo Callegari ◽  
Luca Carbonari ◽  
Giacomo Palmieri
Keyword(s):  
Control Strategy ◽  
Degrees Of Freedom ◽  
Parallel Kinematics ◽  
Analysis And Design ◽  
Pure Rotation ◽  
Analytic Expressions ◽  
Robot Leg ◽  
Moving Platform ◽  
Actuation Systems ◽  
Three Degrees Of Freedom

This paper presents the design of a reconfigurable parallel kinematics machine endowed with three degrees of freedom of pure translation, or alternately of pure rotation. Such reconfigurability results from the use of lockable spherical joints, which realize the connection between each robot leg and the moving platform. Three actuated legs are used to drive the platform motion. The change of configuration occurs only at a specific pose, called home configuration. A control strategy allows to manage the shift phase and activate the two mobilities one at a time. Multibody simulations allowed to analyze the dynamic behavior of the manipulator and to verify the choices made with regard to the robot mechanics and the size of actuation systems. Position and differential kinematics of the manipulator are briefly introduced in order to demonstrate the simplicity of the analytic expressions and the mechanical feasibility of the manipulator.

The Nonexistence of Three Degrees of Freedom Rotational Fully Decoupled Parallel Mechanism

2013 ◽  
Vol 284-287 ◽  
pp. 1951-1955 ◽  
Author(s):  
Yu Lei Hou ◽  
Da Xing Zeng ◽  
Yan Bin Duan ◽  
Yong Sheng Zhao
Keyword(s):  
Control System ◽  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Structure Design ◽  
Theoretical Significance ◽  
Moving Platform ◽  
Configuration Synthesis ◽  
Three Degrees Of Freedom ◽  
Serial Mechanism

The existence of coupling makes the parallel mechanism possess some special advantages over the serial mechanism, while it is just the coupling that brings about the parallel mechanism some difficulties in kinematics and dynamic analysis, the development of control system, and the trajectory planning. Therefore the research on the decoupled parallel mechanism becomes one of the hot of the mechanism fields. While whether the parallel mechanism can realize decouple is the premise for synthesis and analysis of the parallel mechanism. Based on screw theory, the existence of the three degrees of freedom (3-DoF) rotational fully-decoupled parallel mechanism is distinguished. Then taking the 6-PUS/UPU parallel mechanism as example, the rotation angles of the moving platform are measured, which is verified the impossibility of the 3-DoF rotation decoupling. The contents of this paper should possess theoretical significance for the innovative configuration synthesis and structure design of rotational decoupled parallel mechanism.

scholarly journals Discrete Motion Prediction Based on EMG Signals

2019 ◽  
Vol 37 (3) ◽  
pp. 509-514
Author(s):  
Lei Zhang ◽  
Wendong Wang ◽  
Yikai Shi ◽  
Jiahao Liu ◽  
Yang Chu ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Control Method ◽  
Recognition Accuracy ◽  
Robot Arm ◽  
Accuracy Rate ◽  
Exoskeleton Robot ◽  
Designed Experiment ◽  
Three Degree Of Freedom ◽  
Discrete Motion ◽  
Three Degrees Of Freedom

Most of the current rehabilitation equipment is bulky and slow to respond. Therefore, we designed a portable three-degree-of-freedom exoskeleton and discrete-mode control system for this situation. The three degrees of freedom of the exoskeleton robot arm was the wrist swing, the forearm lateral movement, and the elbow rotation. We collected the EMG signals of the biceps and triceps, then filtered the acquired EMG signals and extracted features in order to obtain effective information that reflected the activity intentions. Based on this, a discrete motion control method using the EMG signals to achieve elbow rotation was designed. Experiment suggests that the average pattern recognition accuracy rate can reach more than 90%.

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