Bartosz Minorowicz

Design, modelling and control of a micro-positioning actuator based on magnetic shape memory alloys

This paper presents an actuator based on magnetic shape memory alloys (MSMAs) suitable for precise positioning in a wide range (up to 1 mm). The actuator is based on the spring returned operating mode and uses a Smalley wave spring to maintain the same operating parameters of a classical coil spring, while being characterized by a smaller dimension. The MSMA element inside the actuator provides a deformation when excited by an external magnetic field, but its behavior is characterized by an asymmetric and saturated hysteresis. Thus, two models are exploited in this work to represent such a non-linear behavior, i.e., the modified and generalized Prandtl–Ishlinskii models. These models are particularly suitable for control purposes due to the existence of their analytical inversion that can be easily exploited in real time control systems. To this aim, this paper investigates three closed-loop control strategies, namely a classical PID regulator, a PID regulator with direct hysteresis compensation, and a combined PID and feedforward compensation strategy. The effectiveness of both modelling and control strategies applied to the designed MSMA-based actuator is illustrated by means of experimental results.

Share Mode Magnetorheological Dampers for Vibration Attenuation in Domestic Washing Machines

The article presents a new approach for noise reduction of a household washing machine. The noise sources and phenomenon were described. After investigation of a currently used solution, and alternative available solutions, a new approach was presented. Design and tests of a low costs magnetorheological fluid, semi-active damper were presented. The input parameters for the new damper were identified on the base of investigation of a viscous damper, used in washing machines. The described MR damper was applied in a washing machine suspension system. Next, a study of washing machine acceleration RMS for different unbalanced masses and durum rotations, were performed. During this research the new damper was switched on and off, to shows it influence on the acceleration. The end results show that the new designed dampers can strongly reduce the vibrations of the washing machine housing and its plastic components.

Hysteresis Modelling of a Piezoelectric Tube Actuator

The article concerns about a piezoelectric tube actuator hysteresis. The actuator can bend in two directions and application of this piezo elements can entail new features and capabilities of mechatronic devices. Unfortunately as other smart materials, piezoelectric materials are distinguished by hysteresis phenomenon. Authors present result of displacement measurement, which was performed for decreasing amplitude cosine input signal. Based on this result phenomenological generalized Prandtl-Ishlinskii model was matched. The results of the piezoelectric tube and the model displacement were compered.

Design of Test Stand for Magnetic Shape Memory Alloys Samples and Representation of Obtained Results

Materials with magnetic shape memory gained recognition for their greatest elongation in a group of smart materials, which reaches 10%; another advantage is high operating frequency. Disadvantages must also be considered, these are hysteresis, temperature sensitivity, other nonlinearities and high price. High strain makes it possible to use these materials in actuators design, but it is also possible to apply MSMA in energy harvesters and sensors. This article is linkage between physico-chemical R&D work and basic design of a transducer. Design of a test stand was described, different research scenarios were presented and to sum up this work graphs with the obtained results were placed.

Research of Basic Parameters of Piezoelectric Tube Actuator

The article present basic research of the piezoelectric tube actuator. In this study the actuator was tested for various DC voltages. Further hysteresis and creep effect of the piezo ceramic material were presented. The next point of this research was positioning control of tube under closed loop control. For this purpose classic PID control algorithm was applied, with a negative feedback from laser displacement sensor. The control software was developed under Matlab Simulink and dSPACE control system, which allows fast modification and testing.

Survey on Design and Development of Hexapod Walking Robot, Automated Guided Vehicle and Drone

This paper presents scope of work performed by Students in R&D Group “Mechatron”, where student can develop own ideas under supervision of experienced tutors. The work carried out mostly on autonomous machines and issues related with their control. In recent years, few interesting designs have been developed by Students, three chosen are presented in this paper. In the first section, two designs were presented and it means automated guided vehicle and drone. Presented line follower and its designer participate successfully in nationwide competitions. This vehicle is a result of three years of learning and gaining experience, which allowed for fabrication such complex design. Next described project is a drone, where students prepared 3D printed reinforced lightweight frame. The purpose of this drone is to carriage, e.g., first aid or rescue equipment like ropes. The following and the biggest part of the paper is focused on walking robot. Authors analyzed different kinematics for movement generation and finally, it was decided to perform legs like a cockroach. Based on a kinematic chain, inverse kinematic approach and oscillators Authors successfully evaluated control algorithm which was used for walking generation.

Accuracy of Hysteresis Modeling in Smart Actuator with MSMA

This paper is focused on hysteresis modeling in actuator with magnetic shape memory alloy, briefly MSMA. MSMAs are new group of active materials which change shape in external magnetic field. Active element is made of Ni2MnGa, and it is very suitable to use in actuators for positioning, because this alloy combines great strains (up to 6%) and good dynamic properties. On the other side, it is distinguished by nonlinear behavior. In this case, it is wide saturated asymmetric hysteresis. Reason for that is a kind of internal friction called twining stress. Such drawback does not allow to precise position control in open-loop control system. Described in this paper method for hysteresis modeling is based on mathematical formulation, which utilizes so-called phenomenological models. Hysteresis modeling is provided by generalized Prandtl-Ishlinskii model (GPIM) where hyperbolic tangents were used as envelop functions in play operator. This paper describes modeling accuracy for different GPIM structures. Actuator is designed for high-strain applications up to 1 mm. Data acquisition was provided by dSPACE system.

Study on Mechanical Characteristics in Electromechanical Disengaging Damper

The paper is focused on study of new type of vibration control damper which has been designed, machined, assembled, and calibrated by authors. In typical oil dampers, attenuation force is generated by fixed orifices, where oil passes from one chamber to another. More advanced designs include variable orifices, where it is possible to regulate precisely flow area, e.g., by proportional valve. Thus, these solutions are so-called valve mode, also very popular in whole group of magnetorheological dampers. Another known in engineering type of dampers is based on viscous friction. Steel rood passed through cylinder head, where interference fit creates movement resistance. This paper proposes novel design of damper, where in order to control damping force, simple direct current motor and special mechanism, similar to wedge, has been proposed. To perform basic research on damper’s characteristics, special test stand was designed. Crankshaft mechanism was used to generate reciprocating movement. During tests, one end fixed damper was connected to slider by force transducer. To describe phenomenon of variable damping force, force–displacement and force–velocity characteristics have been registered and described.

Open loop control of piezoelectric tube transducer

Abstract This paper is focused on the open loop control of a piezoelectric tube actuator, hindered by a strong hysteresis. The actuator was distinguished with 22 % hysteresis, which hinders the positioning of piezoelectric actuator. One of the possible ways to solve this problem is application of an accurate analytical inversed model of the hysteresis in the control loop. In this paper generalized Prandtl-Ishlinskii model was used for both modeling and open loop control of the piezoelectric actuator. Achieved modeling error does not exceed max. 2.34 % of the whole range of tube deflection. Finally, the inverse hysteresis model was applied to the control line of the tube. For the same input signal (damped sine 0.2 Hz) as for the model estimation the positioning error was max. 4.6 % of the tube deflection. Additionally, for a verification reason three different complex harmonic functions were applied. For the verification functions, still a good positioning was obtained with positioning error of max.4.56 %, 6.75 %and5.6%of the tube deflection.

Pneumatic single flapper nozzle valve driven by piezoelectric tube

The article presents a construction, static testing and modelling of a single flapper nozzle pneumatic valve. Authors show testing of piezo tube PT230 which distinguishing feature is deflection in two directions. This testing is preliminary work in design of a novel electropneumatic valve. Studies have been performed on a special designed bench which consists of a pneumatic valve, which used piezo tube as a flapper. Data acquisition process and control were performed by dSPACE system. The preformed static pressure control tests, confirmed applicability of tube actuator in flapper nozzle type valves. Obtained results were compared with simulation model prepared in Matlab Simulink software. Streszczenie. Artykul zawiera opis konstrukcji, badania statyczne i modelowanie zaworu typu dysza przyslona. Autorzy zaprezentowali badania piezo rurki model PT230, ktorej cechą charakterystyczną jest mozliwośc odksztalcenia w dwoch kierunkach. Praca ta jest przygotowaniem do konstrukcji nowego zaworu elektropneumatycznego. Badania zostaly wykonane na specjalnie w tym celu wykonanym stanowisku zawierającym zawor, ktorym zastosowano piezo rurke jako przyslone. Procesy akwizycji danych oraz sterowania wykonane zostaly w systemie dSPACE. Przeprowadzone badania statyczne sterowania ciśnieniem wyjściowym, potwierdzają mozliwośc zastosowania piezo rurki w zaworach typu dysza przyslona. Zarejestrowane wyniki poddano porownaniu z modelem przygotowanym w oprogramowaniu Matlab Simulink. (Zawor pneumatyczny typu dysza przyslona z rurką piezoelektryczną jako elementem zadającym)