The paper deals with the problem of reducing the order of an original high-order asymptotically stable linear switching system by independently approximating the (stable) LTI systems corresponding to every fixed value...
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The paper deals with the problem of reducing the order of an original high-order asymptotically stable linear switching system by independently approximating the (stable) LTI systems corresponding to every fixed value of the switching signal. Precisely, each reduced-order model is obtained by minimising the L2 norm of a weighted equation error by means of an efficient algorithm that ensures model stability as well as the retention of a number of first- and second-order information indices, such as the Markov parameters and the impulse-response energies. Then, the stability of the switching system is guaranteed, irrespective of the switching law, by realising the aforementioned reduced models in such a way that they share a common Lyapunov function. To this purpose, a simple state-coordinate transformation amenable to online implementation is applied to the state models initially derived. To improve the approximation, the state after every switching is reset, with due care for stability, according to a fast inclusion-projection procedure. Two examples taken from the literature show that the suggested reduction technique compares favourably with existing techniques.
This work presents a dynamic model of the Stirling engine with a rhombic working mechanism which was combined with the thermodynamic model taking into consideration isothermal heat exchange in the compression and expa...
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This work presents a dynamic model of the Stirling engine with a rhombic working mechanism which was combined with the thermodynamic model taking into consideration isothermal heat exchange in the compression and expansion spaces. On the basis of the conducted thermodynamic analysis for the working space in the Stirling engine and for the physical model of the rhombic drive system, a simulation model was developed using the Matlab&Simulink software. The model was prepared to analyse the influence of the selected thermodynamic and mechanical parameters including among other things: influence of the thermodynamic parameters, among others: temperature of the upper heat source on theoretical work increase and theoretical power. As a result of the performed simulations, the flow of the working gas mass at the control boundaries, as well as the heat flux waveforms were also shown, among other things. As a result of the performed simulations, displacement curves, displacer and piston velocity and acceleration values, as well as adequate gear angular displacement, the angular velocity and angular acceleration have been additionally illustrated. The results presented in this work convey practical information about thermodynamic and dynamic properties of the simulated object, i.e. the Stirling engine with the rhombic drive.
In this paper a Crazyflie 2.0 nano quadrotor helicopter (quadcopter) as an open source experimental platform for research and education in robotics and control engineering has been presented. This low cost, easily exp...
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In this paper a Crazyflie 2.0 nano quadrotor helicopter (quadcopter) as an open source experimental platform for research and education in robotics and control engineering has been presented. This low cost, easily expandable and upgradeable flying robot is here characterized in terms of hardware and software. Three aspects, which demonstrate the potential of broad use of this unmanned aerial vehicle (UAV) by researchers and students, are discussed in the paper. The first one is an acquisition of measurement data from test flights by the proposed, freely available "black-box" software. The second is the use of a new, advanced 4FLY Simulator in order to utilize the MA TLA B~?/Simulink environment to easily implement a mathematical model of Crazyflie 2.0 dynamics, as well as for a synthesis of various types of controllers with support of OpenGL cross-language in the visualization of simulations results. The 4FLY Simulator allows to test autonomous flights (and landings) with obstacles avoidance and to conduct learning and teaching the basics of Crazyflie 2.0 piloting. In the third aspect the authors outlined promising, preliminary results obtained in control of flying robot by pointing device (positioner) and with the support of a vision system, which basis only on a single Kinect sensor.
The interconnection of therapy devices and the associated intelligent usage of available information is a key element for future improvements of medical therapies. Today, the success of an operation is determined by t...
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The interconnection of therapy devices and the associated intelligent usage of available information is a key element for future improvements of medical therapies. Today, the success of an operation is determined by the quality of the therapy devices in connection with the individual knowledge and skills of the surgeon. A novel approach for the automatic, data based enhancement of a modern surgical technique is developed by a research association of clinical, academic and industrial partners. The concept of the project AFluCoMIS is applied to the minimally invasive surgery. The basic idea can be summarized as an increased usage of available data during an intervention. This information can be used to build an assistance system for the clinical staff which supports the surgeon with automatic device configuration, reference value settings and provides monitoring and safety features. A second innovation in the concept is derived from a postoperative correlation analysis between the course of the intervention and the clinical result. Knowledge can be gained from statistical data and improve following interventions. As a result, experience from past interventions is automatically made available to all surgeons by applying the derived parameters to the device. The combination of the surgeon's individual experience and automatically accumulated knowledge improves continuously the conditions for a successful intervention.
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