Mária Tóthová

Simulation of actuator dynamics based on geometric model of pneumatic artificial muscle

Dynamic simulation model of the actuator with two pneumatic artificial muscles in antagonistic connection was designed and built in Matlab Simulink environment. The basis for this simulation model was dynamic model of the pneumatic actuator based on advanced geometric muscle model. The main dynamics characteristics of such actuator were obtained by model simulation, as for example muscle force change, pressure change in muscle, arm position of the actuator. Simulation results will be used in design of control system of such actuator using model reference adaptive controller.

Dynamic simulation model of pneumatic actuator with artificial muscle

Antagonistic actuator with pneumatic artificial muscles (PAMs) is a kinematic structure that consists of two pneumatic muscles acting in opposition to each other, connected through the chain gear. The resulting position of the actuator can be determined by the angle of arm of the load attached to a shaft. Stiffness position of shaft in the given direction is determined by size of pressure of the relevant pneumatic muscle, which is loaded in tension and rotation (position) of shaft is proportional to pressure difference in individual muscle. The main drawback of this actuator is that its dynamic behavior is highly nonlinear. Due to this knowledge of the muscle properties it is necessary to use the model of the muscle. This muscle model of the system is based on modified Hills basic model which consists of a variable damper and a variable spring connected in parallel. All the work on dynamic model was created in Matlab/Simulink environment.

Fuzzy adaptive control for pneumatic muscle actuator with simulated annealing tuning

Pneumatic artificial muscles - based robotic systems usually necessitate the use various nonlinear control techniques in order to improve their performance. Moreover, their robustness to parameter variation, which is generally hardly predictable, should also be tested. Here a fast hybrid adaptive control is proposed, where a conventional PD controller is placed into the feedforward branch and a fuzzy controller is placed into the adaptation branch. The fuzzy controller compensates for the actions of PD controller under conditions of inertia moment variation. The design of fuzzy controller is based on the results of optimization using simulated annealing algorithm. The results confirm fast action of the control scheme as well as its robustness to changes in inertia moment variation.

Operating Modes of Pneumatic Artificial Muscle Actuator

The paper describes operating modes of the PAM based actuator consisting of two pneumatic artificial muscles (PAMs) in antagonistic connection. The artificial muscles are acting against themselves and resultant position of the actuator is given by equilibrium of their forces according to different pressures in muscles. The main requirement for operation of such pneumatic actuator is uniform movement and accurate arm position control according to input desired variable. There are described in paper operation characteristics of the pneumatic artificial muscle in variable pressure and then operation characteristics of the pneumatic artificial muscle actuator consisting of two muscles in antagonistic connection.

Electro-Pneumatic Robot Actuator with Artificial Muscles and State Feedback

Pneumatic position servo system with artificial muscles described in this paper represents feedback control system with non-linear compensation controller of state variables. The designed system demonstrates the operating characteristics that are significantly more favorable than the original characteristics without compensation and they are similar to the properties of the linear system. Such system has principally a shorter control time, significantly lower dynamic control error and it allows apply larger constants of the controller. Following an increased invariance of system against disturbances and also its parametric invariance (robustness) occur.

Static and dynamic properties of the pneumatic actuator with artificial muscles

The paper contains information about the function and basic properties of the actuator based on pneumatic artificial muscles. It describes the design method of control structure of such actuator and shows the nonlinear static and dynamic characteristics of this actuator. The step responses and the non-linear static and dynamic characteristics were measured by authors on the real pneumatic actuator with artificial muscles Festo MAS 20-250.

Simulation Model of Cascade Control of the Heating System

The automatic heating control systems seem to be the nonlinear systems with thermal inertias and time delay. The controller is also nonlinear because its information and power signals are limited. Application of methods, which are available for nonlinear systems together with computer simulation and mathematical modeling, create possibility to reach serious information about researched system. The paper contains the heating system model with the cascade control, simulation model of this system and some simulation results created in Matlab/Simulink environment.

Operating Characteristics of Antagonistic Actuator with Pneumatic Artificial Muscles

Nonconventional actuators based on the pneumatic artificial muscles can be used in manipulators mainly for their lower energy consumption and higher performance at lower weight. In the paper there are compared the dynamic operating characteristics of the antagonistic actuator with the pneumatic artificial muscles obtained by simulation of the different muscle models in Matlab / Simulink environment with the real measured data on the experimental actuator. The results of these simulations and measurements confirmed highly nonlinear operating characteristics of such actuator and also right approach to the design of the actuator model using different muscle models.

Pneumatic Artificial Muscle as Actuator in Mechatronic System

The paper describes basic characteristics of pneumatic artificial muscles (PAM) for using as actuator in mechatronic system. The previous parameters research of individually connected artificial muscles shows, that it is significantly nonlinear system with time delay. Availing these results, problem of using of static and dynamic characteristics of PAMs for control and modeling electropneumatic mechatronic systems based on the artificial muscles occurs. To solve this problems, the paper also deals with design of some models.

Simulation of fuzzy adaptive position controllers for pneumatic muscle actuator

Pneumatic muscle actuators usually use various non-linear control techniques in order to improve their performance. Therefore a hybrid adaptive control scheme with reference model was designed where a conventional PD controller in the feedforward branch and a fuzzy controller in the adaptation branch were used. In the paper two types of fuzzy adaptive position controllers (type Mamdani and type Sugeno) are tested for comparison and simulation results of their using in the pneumatic muscle actuator hybrid adaptive control system are presented.