Study Concerning the Hysteresis of Pneumatic Muscles

2016 ◽  
Vol 841 ◽  
pp. 209-214 ◽  
Author(s):  
Tudor Deaconescu ◽  
Andrea Deaconescu
Keyword(s):  
Control Systems ◽  
Hysteresis Loops ◽  
Experimental Results ◽  
Pneumatic Muscle ◽  
Pneumatic Muscles

A known phenomenon during the contraction/expansion cycles of pneumatic muscles is the occurrence of hysteresis, caused by the elasticity of their component materials. The inherent hysteresis manifest in pneumatic muscles increases the non-linearity of the systems they are included in and consequently the complexity of the related control systems. The paper discusses a number of experimental results obtained for the hysteresis related behaviour of a small size Festo pneumatic muscle, where the specific hysteresis loops were highlighted via isotonic testing.

Accommodation and Convergence in the Human Eye

1969 ◽  
Vol 2 (3) ◽  
pp. T29-T33 ◽  
Author(s):  
F. M. Toates
Keyword(s):  
Control Systems ◽  
Control Model ◽  
Monocular Vision ◽  
Experimental Results ◽  
After Effects ◽  
Human Eye ◽  
Theoretical Predictions ◽  
Accommodative Convergence ◽  
Effect Of Age

The control systems of accommodation and convergence in the human eye are theoretically examined, together with their interactions which represent accommodative convergence and convergence induced accommodation. A control model is proposed in order to help to understand the system, and it is used to make predictions concerning accommodation and convergence placed in conflict, monocular vision, fusional after-effects and the effect of age and drugs on accommodation and accommodative convergence. In each case the theoretical predictions are compared with established experimental results.

The Research on Multi-Axes Automatic Motion Control Systems

2012 ◽  
Vol 459 ◽  
pp. 75-78
Author(s):  
Lian Jun Hu ◽  
Xiao Hui Zeng ◽  
Gui Xu Chen ◽  
Hong Song
Keyword(s):  
Control System ◽  
Embedded Systems ◽  
Automatic Control ◽  
Control Systems ◽  
Motion Control ◽  
Automatic Control System ◽  
Experimental Results

An automatic control system for multi-axes motions based on multi-CPU embedded systems is proposed in the paper, in order to overcome insufficiencies of available multi-axes automatic dispensing control systems. It is shown from experimental results that expected control objectives for multi-axes motions are achieved.

scholarly journals CMOS Realization of All-Positive Pinched Hysteresis Loops

Complexity ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
B. J. Maundy ◽  
A. S. Elwakil ◽  
C. Psychalinos
Keyword(s):  
Hysteresis Loop ◽  
Detailed Analysis ◽  
Hysteresis Loops ◽  
Nonlinear Circuits ◽  
Experimental Results ◽  
First Order ◽  
Pinched Hysteresis Loop ◽  
A Charge ◽  
Pinched Hysteresis ◽  
Nmos Transistors

Two novel nonlinear circuits that exhibit an all-positive pinched hysteresis loop are proposed. These circuits employ two NMOS transistors, one of which operates in its triode region, in addition to two first-order filter sections. We show the equivalency to a charge-controlled resistance (memristance) in a decremental state via detailed analysis. Simulation and experimental results verify the proposed theory.

Control of a Pneumatic Muscle Actuated Rehabilitation System of the Lower Limb Bearing Joints

2015 ◽  
Vol 809-810 ◽  
pp. 706-711
Author(s):  
Tudor Deaconescu ◽  
Andrea Deaconescu
Keyword(s):  
Human Body ◽  
Lower Limb ◽  
Rehabilitation Medicine ◽  
Medical Systems ◽  
Pneumatic Muscle ◽  
Motion Graphs ◽  
Pneumatic Muscles ◽  
Rehabilitation System

The specific objectives of rehabilitation medicine are maintaining and recovering human body functions, as well as preventing dysfunctionalities by means of kinetic and orthotic techniques and a variety of equipment for support and adaptation. The latter are medical systems facilitating the exercise of muscles at constant or variable speeds according to professional recommendations. The paper presents and discusses the control of rehabilitation equipment designed for the passive mobilisation exercises of joints. The novelty of such equipment resides in its actuation by pneumatic muscles, as well as in its control by means of an SPC 200 controller and WinPISA software. The paper presents a number of examples of rehabilitation programmes and the corresponding motion graphs of the rehabilitation equipment sliding block.

Physics-Based Modeling for Lap-Type Joints Based on the Iwan Model

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Wanglong Zhan ◽  
Ping Huang
Keyword(s):  
Distribution Function ◽  
Constitutive Relations ◽  
Hysteresis Loops ◽  
Experimental Results ◽  
Bolted Joints ◽  
Height Distribution ◽  
Proposed Model ◽  
Contact Situation ◽  
Rough Surface Contact ◽  
Nonlinear Constitutive Relation

This study proposed a physics-based heuristic modeling for the nonlinear constitutive relation of bolted joints based on the Iwan model accompanying with the rough surface contact theory. The approach led to an Iwan distribution function which possesses the tribology-related features of the contact interface. In particular, the break-free force distribution function of the Jenkins elements could be expressed in terms of height distribution of surface asperities. The model considered the contribution of elastically, elasto-plastically as well as plastically deformed asperities to the total tangential loads. Following this, constitutive relations for lap-type bolted joints and the corresponding backbone curves, hysteresis loops, and energy dissipation per cycle were obtained. A model application was implemented and the results were compared with the published experimental results. The proposed model agrees very well with the experimental results when the contact parameters met the actual contact situation. The obtained results indicated that the model can be used to study the tangential behaviors of rough surfaces.

A Novel Geometric Formula for Predicting Contractile Force in McKibben Pneumatic Muscles

2017 ◽  
Vol 11 (3) ◽  
pp. 368-377 ◽  
Author(s):  
Guido Belforte ◽  
◽  
Terenziano Raparelli ◽  
Silvia Alessandra Sirolli
Keyword(s):  
Analytical Formula ◽  
Experimental Models ◽  
Design Tool ◽  
Analytical Models ◽  
Pneumatic Muscle ◽  
Muscle Structure ◽  
Pneumatic Muscles ◽  
Muscle Geometry ◽  
Muscle Types ◽  
Specific Muscle

Several analytical models exist in the literature for predicting the behavior of braided pneumatic muscles (McKibben muscles). Such models take into consideration the various variables and parameters that are related to the muscle geometry, material properties, and the loads applied to the system, and propose various relationships between these variables. Owing to the complexity of the muscle structure, in several cases, instead of a physical model, empirical or experimental models are used, which generally have limited validity for specific muscle types, i.e., they are only valid for a restricted range of operating parameters. This study proposes a new analytical formula based on the geometry of a pneumatic muscle studied in the rest and work phases and a simple experimental method to obtain corrective factors useful to design muscles. A mathematical formula can thus be obtained that allows one to deduce the measurements of interest in the system as a function of the specific parameters and permits one to interpret in qualitative terms the behavior of the muscle at each moment for various values of pressure, contraction, and applied load and to identify any critical situations. This model can therefore be a very useful design tool because it allows one to adapt the muscle geometry based on the required forces and contractions for different applications that are compatible with the muscle structure on which the model is based. This paper also presents a method for evaluating the efficiency of the muscles, useful to better use them in different applications.

Robotic grasping of complex shapes: is full geometrical knowledge of the shape really necessary?

Robotica ◽  
1995 ◽  
Vol 13 (5) ◽  
pp. 499-506 ◽  
Author(s):  
M. A. Rodrigues ◽  
Y. E. Li ◽  
M. H. Lee ◽  
J. J. Rowland
Keyword(s):  
Control Systems ◽  
Robot Manipulator ◽  
Vision System ◽  
Experimental Results ◽  
Robotic Grasping ◽  
Virtual Sensors ◽  
Computer Screen ◽  
Complex Shapes ◽  
Different Shapes ◽  
Geometrical Knowledge

SummaryThis paper aims at contributing to a sub-symbolic, feedback-based “theory of robotic grasping” where no full geometrical knowledge of the shape is assumed. We describe experimental results on grasping 2D generic shapes without traditional geometrical processing. Grasping algorithms are used in conjunction with a vision system and a robot manipulator with a three-fingered gripper is used to grasp several different shapes. The altorithms are run on the shape as it appears on the computer screen (i.e. directly from a vision system). Simulated gripper ringer with virtual sensors are configured and positioned on the screen whose inputs are controlled by moving their position relative to the image until an equilibrium is reached among the control systems involved.

Design and Control of a Frog-Inspired Swimming Leg Powered by Pneumatic Muscle

2016 ◽  
Author(s):  
Jizhuang Fan ◽  
Gangfeng Liu ◽  
Huan Wang ◽  
Wei Zhang ◽  
Yanhe Zhu
Keyword(s):  
Dynamic Model ◽  
Step Response ◽  
Joint Control ◽  
Pneumatic Muscle ◽  
Experiment Platform ◽  
Pneumatic Muscles ◽  
Ankle Joints ◽  
Self Tuning ◽  
And Control ◽  
Swimming Leg

According to the shortages of previous generation of frog inspired robot, antagonistic joint based frog inspired leg was designed. With the multi-DOFs of hip, knee and ankle, the designed leg was able to perform various frog swimming modes. The dynamic model of antagonistic joint based on advanced pneumatic muscle model was established in MATLAB/Simulink environment. Besides, the servo control strategy of joint angle was studied based on the dynamic model of antagonistic joint. The PID and self-tuning fuzzy control were utilized to control the antagonistic joint. According to different swimming modes, joint trajectories of hip, knee and ankle were created by inverse kinematics based on the frog swimming mechanism. Therefore, the leg was controlled by the separated controls of hip, knee and ankle joints. Feasibility of pneumatic antagonistic joint control was validated via step response experiments with different loads. Finally, the experiment platform was established to carry swimming experiments with the developed frog-inspired swimming leg. The feasibility of antagonistic frog inspired swimming leg driven by pneumatic muscles was validated.

Experimental characterization and control of a magnetic shape memory alloy actuator using the modified generalized rate-dependent Prandtl–Ishlinskii hysteresis model

2018 ◽  
Vol 232 (5) ◽  
pp. 506-518 ◽  
Author(s):  
Saeid Shakiba ◽  
Mohammad Reza Zakerzadeh ◽  
Moosa Ayati
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Excitation Frequency ◽  
Hysteresis Loops ◽  
Experimental Results ◽  
Hysteretic Behavior ◽  
Magnetic Shape Memory ◽  
Shape Memory Alloy Actuator ◽  
Rate Dependent ◽  
Magnetic Shape Memory Alloy

In this article, two models are used, namely rate-independent and rate-dependent generalized Prandtl–Ishlinskii, to characterize a magnetic shape memory alloy actuator. The results show that the rate-independent model cannot consider the effect of input excitation frequency, while the rate-dependent model omits this drawback by defining a time-dependent operator. For the first time, the effects of excitation frequency on the hysteretic behavior of magnetic shape memory alloy actuator are investigated. In this study, five excitation voltages with different frequencies in the range of 0.05–0.4 Hz are utilized as inputs to the magnetic shape memory alloy actuator and the displacement outputs are measured. Experimental results indicate that, with increasing the excitation frequency, the size of the hysteresis loops changes. Since the generalized rate-dependent Prandtl–Ishlinskii model cannot consider the asymmetric hysteresis loops, in the developed model, a tangent hyperbolic function is applied as an envelope function in order to improve the capability of the model in characterizing the asymmetric behavior of magnetic shape memory alloy actuator. The parameters of both rate-dependent and rate-independent models are identified by genetic algorithm optimization. The results reveal that the rate-independent form is not capable of accurately describing the hysteretic behavior of magnetic shape memory alloy actuator for different input frequencies. Simulation and experimental results also demonstrate the proficiency of the developed model for precise characterization of the saturated rate-dependent hysteresis loops of magnetic shape memory alloy actuator. In addition, the proposed model is utilized for determining a proper range for controller coefficients during controller design.

The Application of Communication between SLC500 PLC and Profibus-DP Fieldbus

2014 ◽  
Vol 668-669 ◽  
pp. 1351-1354
Author(s):  
Shou Tao Li ◽  
Wei Jiang ◽  
Hai Ying Qi
Keyword(s):  
Control Systems ◽  
Data Communication ◽  
Response Speed ◽  
Experimental Results ◽  
Practical Application ◽  
Communication Efficiency ◽  
Profibus Dp

SLC500 PLC can not directly communicate with the Profibus device, which limits its practical application. This paper studies the Profibus protocol and proposes a scheme to realize communication between SLC500 PLC and Profibus network through Flex I/O module, which is prepared for applying SLC500 PLC in multi-protocol environments. The proposed solution can improve the communication efficiency and the response speed in control systems. Experimental results have validated the proposed method’s accuracy, reliability and efficiency in data communication.

Sign in / Sign up

Export Citation Format

Share Document