A novel dynamic evaluation method and its application to a 4-DOF parallel manipulator

2022 ◽  
Vol 168 ◽  
pp. 104627
Author(s):  
Jun Wu ◽  
Hao Ye ◽  
Guang Yu ◽  
Tian Huang
Water Policy ◽  
2018 ◽  
Vol 20 (2) ◽  
pp. 410-428 ◽  
Author(s):  
Yongnan Zhu ◽  
Lei Li ◽  
Yong Zhao ◽  
Zhongmin Liang ◽  
Haihong Li ◽  
...  

Abstract We used system theory to analyze the structure of a regional drought disaster system and separated the drought disaster risk system into three subsystems. These were drought disaster-causing factors, disaster-inducing environments, and disaster-bearing bodies. Analysis of the main factors of these subsystems allowed the establishment of a regional comprehensive drought disaster risk evaluation index system. To simultaneously evaluate the distribution and development trends of the regional comprehensive drought disaster risk, we established a dynamic evaluation model. Based on the ideas of the projection pursuit clustering method and the dynamic comprehensive evaluation method, the model can make use of multi-dimensional space–time drought disaster information. The model was applied to evaluate comprehensive drought disaster risk in the Xuzhou region, China. The evaluation results show that the method was able to illustrate the development trend and distribution of the comprehensive drought disaster risk in the Xuzhou region. The clustering zoning results show that Pizhou City is the area with the highest risk in Xuzhou, while Fengxian has the lowest. The development trend of comprehensive drought disaster risk with time is not significant.


Meccanica ◽  
2015 ◽  
Vol 51 (7) ◽  
pp. 1571-1581 ◽  
Author(s):  
Margherita Forlani ◽  
Nicola Sancisi ◽  
Michele Conconi ◽  
Vincenzo Parenti-Castelli

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xu Han ◽  
Fuping Feng ◽  
Ziyuan Cong

The existing statistical evaluation methods of caprock sealing ability in CO2 sequestration engineering only take into account the sealing ability of caprocks before sequestration but cannot reflect the retained sealing ability of caprock after hydrochemical reactions. A microscopic sealing evaluation method of caprock was established based on the microscopic mechanism of chemical reaction and the breakthrough pressure of caprock which, changes with the time of CO2 sequestration, was taken as the dynamic evaluation index. The results show that the change of microstructure parameters such as the average pore radius after dissolution is the essential reason that affects the variation of the caprock microscopic sealing property. Dissolution or precipitation of different caprock minerals during the chemical reaction process is the key factor that determines the decrease or increase of caprock microscopic sealing property. The evaluation method can reflect the change of microscopic sealing property of the caprocks in different areas as the sealing time goes and provides an efficient and practical quantitative evaluation method for the initial formation site selection and safety sealing in the later stage.


2012 ◽  
Vol 178-181 ◽  
pp. 479-484
Author(s):  
Xiao Ni Zhang ◽  
Xian Min Li

This paper describes a novel laboratory technique for characterizing the scale inhibitors performance of reverse osmosis. The experiment was carried out by operating the RO system in a once-through flow mode which was operated by continuous withdrawal of concentrate and permeate. The concentration ratio of reverse osmosis system is calculated by mass or flow or volume of permeate and concentrate. The performance of scale inhibitors was evaluated according to the scale ion concentration of concentrate. The results showed that the method can screen out the performance of anti-scalants quickly and with low error.


Author(s):  
Liping Wang ◽  
Dong Wang ◽  
Jun Wu

Dynamics evaluation is one of the core research contents of robotics, especially for the parallel manipulators, which are usually working with high acceleration. The general dynamics evaluation methods mainly deal with the acceleration of end-effector and magnitude of driving force based on the general inertia/mass matrix, and ignore the gravity. However, with the change of the placement mode of a parallel manipulator, the gravity would have a great effect on the dynamics of a heavy parallel manipulator. On the other hand, there still some other properties should be evaluated, such as the acceleration sensitivity of each driving shaft caused by gravity, the driving force uniformity when driving force achieves its maximum value. For these reasons, this paper investigates a dynamics evaluation method considering gravity and driving force uniformity. First, the limitations of general evaluation methods are described; next, the proposed dynamics evaluation method is given, including acceleration sensitivity analysis and the driving force uniformity; finally, by taking a typical horizontal parallel tool head as an example of study, a complete dynamics evaluation work is performed by using the proposed method.


2021 ◽  
Vol 283 ◽  
pp. 01047
Author(s):  
Qun Luo ◽  
Tianlong Zhao

The study on deformation characteristics of structural plane is the research foundation of structural plane mechanics and hydraulics. In this paper, a calculation method for dynamic evaluation of the stability of slope controlled by structural plane based on deformation characteristics was proposed on the basis of shear reinforcement three-fold line constitutive model, and it was applied to the example of Raytheon landslide in Chongqing-Guizhou high-speed railway. By comparison, the calculated results were in good agreement with the measured displacement results, and the displacement development process of the dangerous rock mass can be well simulated, thus verifying the feasibility and engineering practicality of the method.


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