Power/energy metrics for controller evaluation of actuators similar to biological systems (original) (raw)

Actuator design using biomimicry methods and a pneumatic muscle system

Control Engineering Practice, 2006

An empirical and theoretical study is conducted on a special actuator termed ''pneumatic muscle'' (PM) being used in a force control system framework. Such an actuator has similarities to biological systems and has many advantages (extremely high power/ weight, power/volume and power/energy ratios). However, due to its inherent nonlinearities, this actuator suffers from poor position and force control. The study described here accomplishes three main goals. (1) A force control system is developed within an open and closed loop framework to emulate how biological systems work in an agonist-antagonist framework. (2) The PM used in the study has such strength that it excites the frame dynamics. This undesired dynamic response is then effectively cancelled using an impedance model control scheme. (3) The PM is demonstrated to both change length yet still produce force in a controlled manner.

A comparison study on pneumatic muscles and electrical motors

2008 IEEE International Conference on Robotics and Biomimetics, ROBIO 2008, 2008

Pneumatic Artificial Muscles also known as "PAM" and "PM", are famous as very light actuators in the current literature. The reason stated in the literature for such claim is their lower "power to weight" ratio compared to other type of actuators namely pneumatic cylinders and electrical motors. However using the "power to weight" ratio of actuators for claiming the lightness of an actuator is questioned in this paper, and a new approach for such comparison is introduced. In this paper a comparison study was made between electrical rotary actuators and PMs on the basis of the τ.α value. It is showed that claims which consider PMs as lighter actuators compared to the other types of actuators are not precise and are highly questionable since some factors are neglected in comparison between the weight of the actuators.

A survey on pneumatic muscle actuators modeling

2011 IEEE International Symposium on Industrial Electronics, 2011

The aim of this article is to provide a survey on the most popular modeling approaches for Pneumatic Muscle Actuators (PMAs). PMAs are highly non-linear pneumatic actuators where their elongation is proportional to the interval pressure. During the last decade, there has been an increase in the industrial and scientific utilization of PMAs, due to their advantages such as high strength and small weight, while various types of PMAs with different technical characteristics have been appeared in the literature. This article will: a) analyze the PMA's operation from a mathematical modeling perspective, b) present their merits and drawbacks of the most common PMAs, and c) establish the fundamental basis for developing industrial applications and conducting research in this field.

Pneumatic muscle actuators within robotic and mechatronic systems

2015

Pneumatic artificial muscles (PAMs) as soft, lightweight and compliant actuators have great potential in applications for the actuations of new types of robots and manipulators. The favourable characteristics of fluidic muscles, such as high power-to-weight ratio and safe interaction with humans are also very suitable during the process of musculoskeletally rehabilitating patients and are often used in making artificial orthoses. This technology, despite the problems of control relatng to nonlinear phenomena, may also have wide future applications within industrial and mechatronic systems. This paper presents several experimental systems actuated by PAMs, which have been designed as test models within the fields of mobile robots, mechatronics, fluid power systems and the feedback control education of mechanical engineering students. This paper first presents the design and construction of a four legged walking robot actuated by pneumatic muscles. The robot has a fully autonomous system with a wireless application platform and can be controlled using a cell phone. Then the paper describes the design and construction of the prototype of an actively-powered ankle foot orthosis. This orthosis device actuated by a single PAM is able to provide the appropriate functions required during the rehabilitations of patients and the loss of mobility. Then the paper focuses on the design and control of a ball and beam system with an antagonistic muscle pair for generating the necessary torque for beam rotation. This mechatronic balancing mechanism falls into the category of unstable, under-actuated, multivariable systems with highly nonlinear dynamics. The final section of the article presents the design and control of a single-joint manipulator arm with pneumatic muscle actuators that enable some new features for the controlled systems.

Numerical Modelling and Experimental Validation of a Pneumatic Muscle Actuator

Proceedings of the JFPS International Symposium on Fluid Power, 1999

In this paper a modification of the McKibben pneumatic muscle, following the idea of a research group from the University of Warsaw, is implemented and manufactured. The muscle consists of asilicon bladder that is attached at either end to fittings; it has the shape of a tube. Inside the silicon bladder longitudinal high resistance cables are inserted with some circular rings. When the internal bladder is pressurised the actuator shorten. A Finite Element Modelling, using the Mooney-Rivlin formulation with two coefficients for the rubber and with truss elements for the longitudinal cables of the muscle, is used to forecast its behaviour. A prototype has been manufactured. A test bed has been developed to measure the mechanical characteristics of the actuator. The results of the comparison between the model and the prototype are presented and discussed. The F.E. model optimised in this way can be used to design every shape of this kind of pneumatic muscle actuator and to define simplified design procedure.

Pneumatic Muscle-Based Actuator for Industrial Robotic Applications

Proceedings of 2017 the 7th International Workshop on Computer Science and Engineering, 2017

The outstanding feature of the pneumatic artificial muscle is its high power to weight ratio vastly outperforming both pneumatic cylinder and DC motor. This feature is very important for using of pneumatic muscle-based actuators in industrial robotic systems where high forces and stiffness of mechanism are often required. The most common so far produced and used type of pneumatic artificial muscle is McKibben muscle and it is now made commercially available by different companies (e.g. Festo). In the paper there are described some of its characteristics and principles of control important for using as actuator for industrial robotic applications.

The selection of mechanical actuators based on performance indices

Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 1997

A method is presented for selecting the type of actuator best suited to a given task, in the early stages of engineering design. The selection is based on matching performance characteristics of the actuator, such as force and displacement, to the requirements of the given task. The performance characteristics are estimated from manufacturers' data and from simple models of performance limitation such as heat generation and resonance. Characteristics are presented in a graphical form which allows for a direct and systematic comparison of widely different systems of actuation. The actuators considered include man-made actuators (such as hydraulic, solenoid and shape memory alloy) and naturally occurring actuators (such as the muscles of animals and plants).

Studies on the Applicability of the Pneumatic Muscle in Industry

journals.indexcopernicus.com

The evolution underwent by the technology during the last decade facilitated utilization of pneumatic muscle in many applications, particularly in the field of industrial robots. The pneumatic muscles are lightweight actuators, able to generate high torques at low and moderate speeds, ...

Applications of Pneumatic Muscles Developed at the Festo Regional Research and Training Centre of Braşov

2013

Compressed air is one of the most important sources of energy in industry, pneumatic actuations tending to hold an increasing share in the conception of modern industrial systems. At present, due to the development of new pneumatic components and systems assemblies of high complexity can be achieved, many of them with applicability in robotics. Such a component is the pneumatic muscle, increasingly deployed in actuation systems, particularly in the field of industrial robots. The paper presents some of the results of research conducted at the Festo Regional Research and Training Centre (FRRTC) at Transilvania University of Braşov.

Measurements and simulation of a pneumatic muscle actuator for a rehabilitation robot

Simulation Practice and Theory, 1995

The performance of a pneumatic muscle actuator, invented by Jim Hennequin and used in a prototype wheelchair-mounted robot arm designed by the first author is reported. Experimental measurements were made of the output torque versus rotary motion and internal pressure. The torque available for a muscle of size 60 mm width by 90 mm length ranges from 1 to 15 Nm. The rotary stiffness of this muscle is 0.081 Nm/deg. A theory based on thermodynamic principles indicates that the efficiency of the pneumatic muscle actuator reaches a maximum of 67%. A simulation model of the dynamic behaviour of the muscle attached to the robot arm using one-dimensional flow theory was written in ACSL (Advanced Continuous Simulation Language). The resultant simulation gives good agreement to within f 5% of the experimental values. . 0928-4869/95/$09.50 0 1995 -Elsevier Science B.V. All rights reserved SSDI 0928-4869(95)00010-O 82 S. D. Prior, A.S. White / Simulation Practice and Theory 3 (1995) 81 -I I7 Several other wheelchair-mounted robotic systems have been developed in the past twenty years, notably by Spar Aerospace of Canada [32], the VA Medical Center of New York [ 191, the Jet Propulsion Laboratory of the California Institute of Technology and the University of Virginia.