The paper deals with the control of underactuated mechanical systems between equilibrium positions across the singular positions. The considered mechanical systems are in the gravity field. The goal is to find feasible trajectory connecting the equilibrium positions that can be the basis of the system control. Such trajectory can be stabilized around both equilibrium positions and due to the gravity forces the mechanical system overcomes the singular positions. This altogether constitutes the control between the equilibrium positions. The procedure is demonstrated on the different inverse pendulum mechanisms.
The role of Computer Aided Engineering in research as well as product development has been significantly increased during two last decades. The growing demands on the simulation address not only monodisciplinary phenomena but also phenomena from
different engineering branches. The current state-of-the-art simulation tools allow two basic approaches for meeting the demands, either coupling of various specialised simulation codes or application of multiphysical simulation tools.
This paper focuses on the simulation approaches for the multidisciplinary tasks and particularly on the connection of specialised simulation tools by interfaces. It classifies the interfaces between specialised software packages in general and gives some case studies using the coupling of specialised simulation tools. Finally, the development stages of an interface between civil and mechanical systems are presented. and Obsahuje seznam literatury
The paper deals with the non-vibration control of electronic cams. Described approach is based on shaping of the command input. The goal is precise positioning without residual vibration in final position. The models of different configurations of electronic cams are used - the simple traditional one, the serial one, the parallel one, the multi-input one. The generalized approach to input shaping control is described that allows synthesis of the shaping functions with arbitrary time length. These functions could be further transformed to the shapers with re-entry property. It is demonstrate and explained that some advanced shaping functions are more robust against model misalignment than the simple Heaviside pulse shapers. This generalized input shaping control is applied to different kinds of electronic cams. and Obsahuje seznam literatury
This paper deals with the identification of nonlinear dynamic systems by LOLIMOT algorithm, which allows to gradually build the neuro-fuzzy model of the identified system. The mathematical model as well as the identification algorithm for MISO and MIMO systems are described. The methodology is demonstrated on several examples. and Obsahuje seznam literatury
The paper deals with the calibration methods for machines with parallel kinematics. The procedures are based on Newton method for numerical solution of overconstrained system of nonlinear equations. The methods are applied on redundantly actuated machine with planar kinematics named ‘Sliding Star‘. The redundant measurements of relative motions in joints allow on-line calibration in real time of machine tool operation. This could significantly improve the thermal inaccuracy of machine tools with parallel mechanisms. and Obsahuje seznam literatury