scholarly journals Analysis of a planetary gear modeled with a contour graph taking into account the method of parametric play structures

Mechanik ◽  
2017 ◽  
Vol 90 (7) ◽  
pp. 640-642 ◽  
Author(s):  
Adam Deptuła ◽  
Józef Drewniak ◽  
Marian A. Partyka

Previous applications of the graph theory concerned the modeling of gears for dynamic analysis, kinematic analysis, synthesis, structural analysis, gearshift optimization and automatic design based on so-called graph grammars. Some tasks can be performed only by using methods resulting from a graph theory, e.g. enumeration of structural solutions. The contour plot method consists in distinguishing a series of consecutive rigid units of the mechanism, forming a closed loop (so-called contour). At a later stage, it is possible to analyze the obtained contour graph as a directed graph of dependence. The work presents an example of the use of game-tree structures for describing the contour graph of a planetary gear. As a result of the decomposition of the graph in the dependence on each of the vertices, game-tree structures are obtained, which allow calculate algorithmically.

2021 ◽  
Vol 143 (9) ◽  
Author(s):  
Hanqiao Sun ◽  
Xiangyang Xu ◽  
Yanfang Liu ◽  
Peng Dong ◽  
Shuhan Wang ◽  
...  

Abstract Planetary gear set (PGS) has been one of the best components to constitute a transmission configuration, including the dedicated hybrid transmission (DHT). Using different synthesis approaches, the DHT configurations can be obtained through algorithms. However, different synthesis results correspond to different connection states of the planetary gear system. There are a certain number of results that violate the motion requirements of the mechanical principal need to be detected and removed. Therefore, this paper presents a novel modeling method to systematically remove the interference structures, with graph theory in structural synthesis. Based on the original graph theory, this paper proposes an equivalent replacement modeling method to convert the motor graph model into a brake-like graph model. Based on the conversion, avoid the appearance of the hanging points in the graph model. By applying the proposed approach, a DHT structure proves the feasibility of the method. The proposed detection approach can systematically detect all the PGS-based transmission with multi-PGSs, multi-shifting elements, and multi-power sources.


Author(s):  
Janzen Lo ◽  
Dimitris Metaxas

Abstract We present an efficient optimal control based approach to simulate dynamically correct human movements. We model virtual humans as a kinematic chain consisting of serial, closed-loop, and tree-structures. To overcome the complexity limitations of the classical Lagrangian formulation and to include knowledge from biomechanical studies, we have developed a minimum-torque motion planning method. This new method is based on the use of optimal control theory within a recursive dynamics framework. Our dynamic motion planning methodology achieves high efficiency regardless of the figure topology. As opposed to a Lagrangian formulation, it obviates the need for the reformulation of the dynamic equations for different structured articulated figures. We use a quasi-Newton method based nonlinear programming technique to solve our minimum torque-based human motion planning problem. This method achieves superlinear convergence. We use the screw theoretical method to compute analytically the necessary gradient of the motion and force. This provides a better conditioned optimization computation and allows the robust and efficient implementation of our method. Cubic spline functions have been used to make the search space for an optimal solution finite. We demonstrate the efficacy of our proposed method based on a variety of human motion tasks involving open and closed loop kinematic chains. Our models are built using parameters chosen from an anthropomorphic database. The results demonstrate that our approach generates natural looking and physically correct human motions.


Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yongqing Fan ◽  
Tiantian Xiao ◽  
Zhen Li

A distributed fuzzy adaptive control with similar parameters is constructed for a class of heterogeneous multiagent systems. Unlike many existing works, the dimensions of each multiagent dynamic system are considered to be nonidentical in this paper. Firstly, similar properties for different dimensions of multiagent systems are introduced, and some similar parameters among multiagent systems are also proposed. Secondly, a distributed fuzzy adaptive control on the basis of similar parameters is designed for the consensus of leader-follower multiagent systems. Following the graph theory and Lyapunov stability approach, it is concluded that UUB (uniformly ultimately bounded) of all signals in the closed-loop system can be guaranteed, and the consensus tacking error converges to a small compact zero set. Finally, a simulation example with different dimensions is provided to illustrate the effectiveness of the proposed method.


2008 ◽  
Vol 130 (5) ◽  
Author(s):  
Y. V. D. Rao ◽  
A. C. Rao

New planetary gear trains (PGTs) are generated using graph theory. A geared kinematic chain is converted to a graph and a graph in turn is algebraically represented by a vertex-vertex adjacency matrix. Checking for isomorphism needs to be an integral part of the enumeration process of PGTs. Hamming matrix is written from the adjacency matrix, using a set of rules, which is adequate to detect isomorphism in PGTs. The present work presents the twin objectives of testing for isomorphism and compactness using the Hamming matrices and moment matrices.


2012 ◽  
Vol 165 (3) ◽  
pp. 314-325
Author(s):  
Adam DEPTUŁA ◽  
Marian PARTYKA

The paper concerns the application of dependence graphs and game tree-structures for the analysis and synthesis of the dynamic properties of machine systems. Graph distributions starting from various beginning vertices are presented in this paper. In order to illustrate the acceptable subsystems of parent machine system, similarities and differences between complex parametric trees are also given. It is also possible to find the part common to all the game tree-structures and describe it over separate design or operational parameters.


2017 ◽  
Vol 15 (1) ◽  
pp. 15-21
Author(s):  
Gabriela Achtenová

Abstract The article describes the concept of modular stand, where is possible to provide tests of gear pairs with fixed axes from mechanical automotive gearboxes, as well as tests of separate planetary sets from automatic gearboxes. Special attention in the article will be paid to the variant dedicated for testing of planetary gear sets. This variant is particularly interesting because: 1) it is rarely described in the literature, and 2) this topology allows big simplification with respect to testing of standard gearwheels. In the planetary closed-loop stand it is possible to directly link two identical planetary sets. Without any bracing flange or other connecting clutches, shafts or gear sets, just two planetary sets face-to-face will be assembled and connected to the electric motor.


Mechanik ◽  
2017 ◽  
Vol 90 (7) ◽  
pp. 574-576
Author(s):  
Adam Deptuła ◽  
Piotr Osiński

Presented are possible applications of acoustic diagnostics in inspecting the technical condition of an internal combustion engine with autoignition on the example of the Fiat drive unit with common rail system. As a result of measuring the sound pressure level for specific faults and comparing the noise generated by the motor running smoothly, the detailed maps of changes in the acoustic spectrum are possible to generate. These results may be helpful in the future diagnostics of internal combustion engines. The results of scientific work in the area of research, design and operation of internal combustion engines, conducted at the Department of Automotive Engineering, in cooperation with the Laboratory of Hydraulic Drives & Vibroacoustics of Machines at the Wroclaw University of Technology are included. It has developed an authoritative method of identifying the type of engine damage using game-tree structures. An integrated decision system for induction machine learning was developed to test and identify acoustic properties.


Trudy NAMI ◽  
2021 ◽  
pp. 6-21
Author(s):  
A. Deptuła ◽  
R. Kh. Kurmaev

Introduction (problem statement and relevance). The graphs, logic and game-tree structures methods have been used in mechanics. The purpose of modeling an automatic gearbox with graphs can be versatile, namely: determining the transmission ratio of individual gears, analyzing the speed and acceleration of individual rotating elements.The purpose of the study. The article presents the application of decision trees in the analysis of automatic gearboxes modeled with the Hsu graph.Methodology and research methods. The paper presents a method of generating game tree structures that allow to change the values of decision parameters in the issues of decision making and knowledge generation. Specifying the rank of importance, in which order you should change individual items to active, allows you to detect the so-called redundant or temporarily redundant components for a given gear currently under consideration.Scientific novelty and results. At each stage of optimization, a tree is generated, selecting the optimal decisions. Then, vertices can be added to the tree that represent the optimal responses of the system to changes in arithmetic construction parameters.Practical significance. The most important in this regard will be the selection of the optimal programming environment with the possibility of installing the program in laboratory


2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Wenjian Yang ◽  
Huafeng Ding ◽  
Bin Zi ◽  
Dan Zhang

Planetary gear trains (PGTs) are widely used in machinery to transmit angular velocity ratios or torque ratios. The graph theory has been proved to be an effective tool to synthesize and analyze PGTs. This paper aims to propose a new graph model, which has some merits relative to the existing ones, to represent the structure of PGTs. First, the rotation graph and canonical rotation graph of PGTs are defined. Then, by considering the edge levels in the rotation graph, the displacement graph and canonical displacement graph are defined. Each displacement graph corresponds to a PGT having the specified functional characteristics. The synthesis of five-link one degree-of-freedom (1DOF) PGTs is used as an example to interpret and demonstrate the applicability of the present graph representation in the synthesis process. The present graph representation can completely avoid the generation of pseudo-isomorphic graphs and can be used in the computer-aided synthesis and analysis of PGTs.


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