To deal with the problem of stable walking of quadruped robots on slopes, a gait planning algorithm framework for quadruped robots facing unknown slopes is proposed. We estimated the terrain slope by the attitude information measured by the inertial measurement unit (IMU) without relying on the robot vision. The crawl gait was adopted, and the center of gravity trajectory planning was carried out based on the stability criterion zero-moment point (ZMP). Then, the augmented random search (ARS) algorithm was used to modulate the parameters of the Bezier curve to realize the planning of the robot foot trajectory. Additionally, the robot can adjust the posture in real time to follow the desired joint angle, which realizes the adaptive adjustment of the robot’s posture during the slope movement. Simulation experiment results show that the proposed algorithm for slope gait planning can adaptively adjust the robot’s attitude and stably pass through the slope environment when the slope is unknown.
Human reliability has been a focus in system reliability and safety researches since 1960s, and now human factor has become an increasingly important reason which affects system reliability. Numerical control machining system characterized by man-machine interaction can be applied to automatic parts machining with high efficiency. However, professional and technical staffs are still needed for clamping, positioning, inspection and others. So there is no doubt that the quality of the parts might be influenced by personnel behaviour. What’s more, on-site staff is responsible for handling potential fault directly. The study on human error plays an important role to ensure the quality and reduce industrial accident. Holistic Decision Tree (HDT) is a dynamic Human Reliability Analysis (HRA) method, emphasizing the wholeness of man-machine interaction. This paper tries to use an optimized HDT method to investigate human reliability in numerical control machining system. In order to obtain a rational order of the importance of each IF, this paper incorporates entropy weight method to the conventional expert method to determine the relative weight value of each human behaviour influence factor (IF), and finally calculates the human error probability (HEP).
Nowadays junior high school students are working under great pressure of learning.It' s hard for them to improve their results although they did a lot of math exercises.They will bite their nails when the problem is flexible.The key to learning faster and acquiring the skill is to improve their abilities of learning.It' s necessary for teachers to design the content of courses elaborately.According to my working experiences,exercises need to be succinctly cued and easily modifiable in class,the background of the concept and the example problems should be presented in different ways,embodying the training of the concept variation and the training of the process of variation.Mean to reduce the heavy burdens and improve the students' abilities by means of the training of the variation.
As an important part in sortie/recovery process, the dispatch of carrier aircraft not only affects the sortie/recovery efficiency and safety, but also has severe influence on the carrier's combat efficiency and the comprehensive support capability. Path planning is the key to improve the efficiency and safety during the dispatch process. The main purpose of this paper is to propose a comprehensive investigation of techniques and research progress for the carrier aircraft's dispatch path planning on the deck. Three different dispatch modes of carrier aircraft and the corresponding modeling technologies are investigated, and the aircraft's dispatch path planning techniques and algorithms have been classified into different classes. Moreover, their assumptions and drawbacks have been discussed for single aircraft and multiple aircraft. To make the research work more comprehensive, the corresponding tracking control methodologies are also discussed. Finally, due to the similarity of path planning problem between the carrier aircraft's dispatch and those in other fields, this paper provides an exploratory prospect of the knowledge or method learned from other fields.
Tactile sensing is important for robots to perceive the world as it captures the texture and hardness of the object in contact and is robust to illumination and colour variances. However, due to the limited sensing area and the resistance of the fixed surface, current tactile sensors have to tap the tactile sensor on target object many times when assessing a large surface, i.e., pressing, lifting up and shifting to another region. This process is ineffective and time consuming. It is also undesirable to drag such sensors as this often damages the sensitive membrane of the sensor or the object. To address these problems, we propose a cylindrical optical tactile sensor named TouchRoller that can roll around its center axis. It maintains being in contact with the assessed surface throughout the entire motion, which allows for measuring the object continuously and effectively. Extensive experiments show that the TouchRoller sensor can cover a textured surface of 8cm*11cm in a short time of 10s, much more effectively than a flat optical tactile sensor (in 196s). The reconstructed map of the texture from the collected tactile images has a high Structural Similarity Index (SSIM) of 0.31 on average, when compared with the visual texture. In addition, the contacts on the sensor can be localised with a low localisation error, 2.63mm in the center regions and 7.66mm on average. The proposed sensor will enable the fast assessment of large surfaces with high-resolution tactile sensing, and also the effective collection of tactile images.
A net monitor system used to real-time monitor the state of the controller area network(CAN) is designed. In the system,two while loops compose a producer/consumer pattern which is the main program structure. The producer loop responds user actions and the consumer loop handles commands and data.The functions of the system such as data trace,graphics display,signal selection,and write frame are compiled in corresponding sub-Vis.When the messages are transmitted in the bus,the system receives messages from the CAN by a CAN interface card.After data analysis and statistics,the states of the monitored net,such as busload, message rate and so on,are shown in the system.In the experiment,to test the validity of this system,another CAN node is used to send different messages to the monitoring system.The results show that the system can real -time monitor the CAN.
From the arts to culture and cultural industry,and to the cultural and creative industries,by these historical changes,and deeper social factors,we can sum up the commercialization process of cultural products over the years.Reviewed the history of cultural industry,combined with other aspects of socio-economic and policy factors,the cultural industry is undergoing a new round of restructuring.From the text-creating to creativity-oriented,as well as the emergence of creative communities,cultural and creative industry is help to shape a new form of society.
The purpose of this paper is to define the notion of an interval-valued fuzzy subalgebra(briefly,an I-V fuzzy subalgebra) of a sub-BCI-algebra.Necessary and sufficient conditions for an I-V fuzzy set to be an I-V fuzzy subalgebra are discussed.It is proved that all subalgebra of a sub-BCI-algebra can be realized as an I-V level subset of an I-V fuzzy subalgebra of sub-BCI-algebra.A method making a new I-V fuzzy subalgebra from old one is given.
In the traditional environment, because there were many problems in acquisition and transmission of the standard information, the university library couldn't provide well the standard information service. The network environment provides good conditions for the university library to carry out the standard i nformation service. This paper probes mainly into how the university library to carry out the standard information service in the network environment.
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