Višekriterijumska optimalna sinteza pogonskih mehanizama manipulatora utovarivača
Committee membersPetrović, Goran
Milić, Predrag Đ.
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The dissertation defines the general methodology of multicriteria optimal synthesis of the loader drive mechanisms with the Z kinematics manipulator. The methodolo- gy is based on the design science and modular design procedure. The obtained resea- rch results during the development of the methodology are related to: the analysis of parameters of mechanisms functions, generation of variant solutions of mechanisms, definition of criteria for optimization of mechanisms and selection of the best soluti- on of mechanisms by methods of multicriteria decision making. The analysis of fun- ction parameters, which are set at the beginning of the synthesis of manipulator me- chanisms, was performed by dynamic numerical simulation and experimental tests. The results of the analysis show that the load moments of the mechanisms are the greatest during the operation of the material loading, and during the operation of tra- nsferring the material, the moment of gravitational force of the load...ed material has the greatest influence on the mechanisms load. To generate variant solutions of me- chanisms, an optimization area is determined, which includes: transfer parameters – coordinates of joints and lengths of the kinematic chain members of mechanisms and transformation parameters - sizes of hydraulic cylinders. The variant solutions of mechanisms was generated by searching the optimization space, first the transfer parameters are generated - using a genetic algorithm, and then the transformation pa- rameters of the mechanisms - by the sequential search procedure. The obtained set of generated solutions shows that for the same given function parameters it is possible to generate variants of mechanisms with different transformation and transfer para- meters. For the selection of mechanism solutions, from the set of possible generated variant solutions, the following optimization criteria have been developed a) kinema- tic criterion defining the minimum change of back bucket angle when lifting from transport to unloading position, b) criterion of directed breaking force with the aim that the directed loading force of the material has a maximum value, determined for the entire working area of the manipulator, c) tribological criterion with the aim that minimal power losses occurred due to friction in the joints of manipulator mechani- sms, d) time criterion with the aim that the minimum time duration of operations of loading, transport and unloading of the manipulation task, e) mass criterion with the aim that the members of the kinematic chain and drive mechanisms of the manipula- tor have the minimum mass, e) dynamic criterion with the aim that the minimum di- splacements of the support-moving mechanisms of the loader are caused by the mo- tion of the manipulator mechanisms. For the selection of the best variant solution of drive mechanisms, methods of multicriteria decision making were used based on the values of defined objective functions and evaluation of the importance of criteria.