scholarly journals Control strategies for a multiple degree of freedom prosthetic hand

2006 ◽  
Author(s):  
D.P.J. Cotton ◽  
A. Cranny ◽  
P.H. Chappell ◽  
N.M. White ◽  
S.P. Beeby
Keyword(s):  
Control Strategies ◽  
Degree Of Freedom ◽  
Prosthetic Hand

scholarly journals Control Strategies for a Multiple Degree of Freedom Prosthetic Hand

2007 ◽  
Vol 40 (1) ◽  
pp. 24-27 ◽  
Author(s):  
D.P.J. Cotton ◽  
A. Cranny ◽  
P.H. Chappell ◽  
N.M. White ◽  
S.P. Beeby
Keyword(s):  
Control Strategies ◽  
Degree Of Freedom ◽  
Prosthetic Hand

scholarly journals Dynamics analysis and electromagnetic characteristics calculation of permanent magnet 3-degree-of-freedom motor

2019 ◽  
Vol 103 (1) ◽  
pp. 003685041987421
Author(s):  
Zheng Li ◽  
Lingqi Liu
Keyword(s):  
Permanent Magnet ◽  
High Speed ◽  
Permanent Magnets ◽  
Control Strategies ◽  
Core Loss ◽  
Degree Of Freedom ◽  
Theoretical Formula ◽  
Virtual Displacement ◽  
High Speed Rotation ◽  
Actual Operation

This article proposes a conceptual model of a new type permanent magnet 3-degree-of-freedom motor. Its structure consists of an internal rotation module and a peripheral deflection module. It can be driven independently to achieve high-speed rotation and precise tilting of the motor. The 3-degree-of-freedom movement of the motor in space is achieved by the synchronous operation of the rotation and the deflection. In order to explore the loss problem caused by the temperature rise problem in the actual operation of the motor, the eddy current loss and core loss inside the permanent magnet of the motor are analyzed by theoretical formula and finite element method, respectively. Based on the static magnetic field, the gas flux density of two types of rotor permanent magnets in different coordinate systems is analyzed. The motor’s rotation and deflection torque characteristics are calculated using the principle of virtual displacement method. Using the auxiliary technology of the virtual prototype, according to the actual situation of the motor, the corresponding motion hinges and driving forms are summarized, and the control strategies of rotation, deflection, and rotation and deflection simultaneously are planned. The trajectory of the motor is described by observing the selected points. For the motor from product design to prototype testing and to the final processing assembly, a solid theoretical foundation is laid for the proposed work.

Single Degree-of-Freedom Modeling of the Nonlinear Vibration Response of a Machining Robot

2020 ◽  
Vol 143 (5) ◽  
Author(s):  
Yaser Mohammadi ◽  
Keivan Ahmadi
Keyword(s):  
Control Strategies ◽  
Vibration Response ◽  
Industrial Robots ◽  
Degree Of Freedom ◽  
Restoring Force ◽  
Single Degree Of Freedom ◽  
Machining Forces ◽  
Sdof System ◽  
Single Degree ◽  
Machining Robot

Abstract Highly dynamic machining forces can cause excessive and unstable vibrations when industrial robots are used to perform high-force operations such as milling and drilling. Implementing appropriate optimization and control strategies to suppress vibrations during robotic machining requires accurate models of the robot’s vibration response to the machining forces generated at its tool center point (TCP). The existing models of machining vibrations assume the linearity of the structural dynamics of the robotic arm. This assumption, considering the inherent nonlinearities in the robot’s revolute joints, may cause considerable inaccuracies in predicting the extent and stability of vibrations during the process. In this article, a single degree-of-freedom (SDOF) system with the nonlinear restoring force is used to model the vibration response of a KUKA machining robot at its TCP (i.e., machining tool-tip). The experimental identification of the restoring force shows that its damping and stiffness components can be approximated using cubic models. Subsequently, the higher-order frequency response functions (HFRFs) of the SDOF system are estimated experimentally, and the parameters of the SDOF system are identified by curve fitting the resulting HFRFs. The accuracy of the presented SDOF modeling approach in capturing the nonlinearity of the TCP vibration response is verified experimentally. It is shown that the identified models accurately predict the variation of the receptance of the nonlinear system in the vicinity of well-separated peaks, but nonlinear coupling around closely spaced peaks may cause inaccuracies in the prediction of system dynamics.

A 3-ṞPR Parallel Mechanism With Singularities That are Self-Motions

2010 ◽  
Vol 2 (3) ◽  
Author(s):  
Novona Rakotomanga ◽  
Ilian A. Bonev
Keyword(s):  
Parallel Mechanism ◽  
Control Strategies ◽  
Joint Space ◽  
Degree Of Freedom ◽  
Parallel Mechanisms ◽  
Active Joint ◽  
Cartesian Space ◽  
Three Degree Of Freedom

The Cartesian workspace of most three-degree-of-freedom parallel mechanisms is divided by Type 2 (also called parallel) singularity surfaces into several regions. Accessing more than one such region requires crossing a Type 2 singularity, which is risky and calls for sophisticated control strategies. Some mechanisms can still cross these Type 2 singularity surfaces through “holes” that represent Type 1 (also called serial) singularities only. However, what is even more desirable is if these Type 2 singularity surfaces were curves instead. Indeed, there exists at least one such parallel mechanism (the agile eye) and all of its singularities are self-motions. This paper presents another parallel mechanism, a planar one, whose singularities are self-motions. The singularities of this novel mechanism are studied in detail. While the Type 2 singularities in the Cartesian space still constitute a surface, they degenerate into lines in the active-joint space, which is the main result of this paper.

scholarly journals Real Time Pattern Recognition for Prosthetic Hand

2019 ◽  
Author(s):  
Mario A. Benitez Lopez ◽  
Carlos Rodriguez ◽  
Jonathan Camargo
Keyword(s):  
Pattern Recognition ◽  
Real Time ◽  
Degrees Of Freedom ◽  
Mechanical Design ◽  
Control Strategies ◽  
Prosthetic Hand ◽  
Time Pattern ◽  
Precise Control ◽  
Myoelectric Prostheses ◽  
Artificial Neural Network Ann

Abstract Control of prosthetic hands is still an open problem, currently, commercial prostheses use direct myoelectric control for this purpose. However, as mechanical design advances, more dexterous prostheses with more degrees of freedom (DOF) are created, then a more precise control is required. State of the art has focused in the use of pattern recognition as a control strategy with promising results. Studies have shown similar results to classic control strategies with the advantage of being more intuitive for the user. Many works have tried to find the algorithms that best follows the user’s intention. However, deployment of these algorithms for real-time classification in a prosthesis has not been widely explored. This paper addresses this problem by deploying and testing in real-time an Artificial Neural Network (ANN). The ANN was trained to classify three different motions: no grasp, precision grasp and power grasp in order to control a two DOF trans-radial prosthetic hand with electromyographic signals acquired from two channels. Static and dynamic tests were made to evaluate the ANN under those conditions, 95% and 81% accuracy scores were reached respectively. Our work shows the potential of pattern recognition algorithms to be deployed in microcontrollers that can fit inside myoelectric prostheses.

scholarly journals Two-Degree-of-Freedom PID Controller, Its Equivalent Forms and Special cases

2015 ◽  
Vol 4 (4) ◽  
pp. 269
Author(s):  
Haresh A. Suthar
Keyword(s):  
Control System ◽  
English Language ◽  
Control Strategies ◽  
Software Tool ◽  
Degree Of Freedom ◽  
Pid Controllers ◽  
Transport Delay ◽  
Point Tracking ◽  
Special Cases ◽  
Two Degree Of Freedom

<p>The design of control systems is a multi-objective problem so, a two-degree-of-freedom (abbreviated as 2DOF) control system naturally has advantages over a one degree- of-freedom (abbreviated as 1DOF) control system. The main objective of 2DOF control is to control both set point tracking and disturbance rejections.Various 2DOF PID controllers and its equivalent transformations were proposed for industrial use by different researchers. Most of the above researches were published in Japanese language and have not been translated into English language yet. An objective here is to provide detail analysis regarding structure of 2DOF controller, its equivalent forms and its special cases. A system transfer function having transport delay and load disturbance is considered as a test bench to verify various 2DOF control strategies. MATLAB is used as software tool to verify the various 2DOF control strategies. The analysis will be helpful to the engineers and researchers to understand the topic in detail for further exploration.</p>

Design and Control of an Active Palm Roll Joint for the Human Prosthetic Hand

2016 ◽  
Author(s):  
Brad Newby ◽  
Nicholas Youngers ◽  
Visharath Adhikari ◽  
Yimesker Yihun ◽  
Hamid Lankarani
Keyword(s):  
The Elderly ◽  
Degree Of Freedom ◽  
Prosthetic Hand ◽  
Upper Arm ◽  
Complex Tasks ◽  
Arm Strength ◽  
And Control

This paper presents the design and control of a human prosthetic hand with an active palm roll joint. An active palm roll to a prosthetic hand will add a new degree-of-freedom, which can maximize the functionality and capability of performing complex tasks. The palm roll combined with the thumb allows the finger tips to touch one another and pinching to become a possible task for the user. In addition to maximizing the functionality of the hand, the inclusion of an active palm joint in the design provides a useful function for the design of prosthetics for children and the elderly who do not have enough upper arm strength to grasp objects firmly in their hand. The kinematics and workspace analyses of the pinky fingertips with the active palm joint and the thumb are also conducted in this study. With the added palm joint, the interaction of the workspace of the pinky fingertip and the thumb-tip is maximized, which allows grasping and manipulating different sizes and shapes of an object. Experiments are conducted to demonstrate the use of the active palm joint in grasping of objects.

Sign in / Sign up

Export Citation Format

Share Document