| Safety gear performance is an important indicator to prevent the elevator shaft fall accidents, in addition to installation factors, output precision of safety gear pulling bodies is elevator congenital the deciding factor of the "good" or "bad". Therefore, the study of important analysis and design optimization methods has great significance to improve the usefulness of safety gear lifting mechanism.First, Bayesian networks, fuzzy theory and important analysis method is introduced to the important degree which impact the accuracy of safety gear, depending on the structure of the deputy campaign and working conditions of safety to determine Bayesian network node. Considering the logical relationship and multiple states of each factor, the multi-state Bayesian networks affecting the safety gear kinematic accuracy is established. Expert language is transferred into triangular fuzzy number to get fuzzy probability by using language variables. Using "Mean area method" to solve fuzzy probability, the blur information contained in operation ia eliminated. And these data were normalized to give the exact value of each factor, and finally the use of bucket elimination algorithm to calculate the importance of each factor. The calculated method proposed by this paper is correct by comparing the methods and T-S fuzzy fault tree analysis method. The results show that the synchronized factors of safety gear lifting mechanism impact greater on the safety gear. Therefore, a qualitative analysis of movement accuracy of the safety gear pulling bodies is studied in Chapter 3.Secondly, safety gear lifting mechanism is studied. Considering the impact the joint clearance on safety gear pulling kinematic precision, double rocker movement institutions is researched. Under ideal conditions the movement mathematical model of the pulling mechanism of the safety gear is established with clearance. From the geometric constraint equations of planar mechanism, using matrix theory to process model simplification, movement precision error expression of the pulling arm on both sides of security agencies is derived. Using MATLAB symbolic toolbox, both horizontal and vertical lifting arm output point errors were calculated input angle of 100 degrees,98 degrees,96 degrees,94 degrees, 92 degrees and 90 degrees. The movement output error is explored under the different locations, the result is seen as the initial error to verify the accuracy and effectiveness of the optimize design safety gear lifting mechanism in the next chapter.Then, the goal is to optimize the design of the safety gear pulling bodies, design variables are geometric parameters of linkage. To meet the double rocker mechanism and transmission angle constraint conditions, based on the output error matrix theory to build sports multi-objective optimization design of the objective function, the multi-objective optimization design model of safety gear lifting mechanism is established. For the limitations of obtaining information of different experts and different design goals, using the gray theory to allocate the expert’s assessment of each target within a certain range, a quantitative weighting factor for each goal is given. Using MATLAB optimization toolbox and symbols toolbox, optimal geometric parameters making the output displacement error minimum of the safety gear lifting mechanism is solved, which provides theoretical support for remanufacturing and redesign for safety gear.Finally, the mechanism design theory and ADAMS simulation optimization technology is combined, simulation analysis of output point displacement for safety gear lifting mechanism is done. Two. pulling arm position images of the output points are got by modeling, simulation and test of the pulling safety gear agencies, which can be more intuitive understanding of the safety gear pulling kinematic changes over time. At the same time, the simulation results are compared with the calculated values to further verify the correctness and effectiveness of the design optimize model. |
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