Recent Advances on Manipulator Trajectory Planning Methods

2020 ◽  
Vol 13 (4) ◽  
pp. 303-327
Author(s):  
Hongxin Zhang ◽  
Haoran Qiu ◽  
Xu Zhang ◽  
Ping Hu

Background: Traditional manipulator requires professionals to write control programs for specific job requirements so that the end-effector of the manipulator can work following the control instructions. However, the flexibility of the manipulator is not high under the control of off-line programming. With the diversification of the job requirements, the complexity of the work environment has gradually increased. Therefore, the relevant scholars focused their research on the automatic trajectory planning method of the manipulator. They used some algorithms to plan optimal trajectories for the manipulator to automatically avoid obstacles in the complex environment. Researches show that the hybrid optimal trajectory with parameter optimization such as time, energy and impact can be planned by automated programming under some constraint conditions. The trajectory planning is helpful to improve the automation and working efficiency of manipulators for the development of intelligent manufacturing. Objective: Providing references for researchers from related fields by reviewing recent advances of the manipulator trajectory planning. Methods: This paper reviews the latest patents and current representative articles related to the manipulator trajectory planning. The key methods of some references are introduced in several aspects of the algorithm, innovation and principle. Results: Researches on the manipulator trajectory planning in recent 10 years are reviewed. The differences between algorithms in latest patents and current articles are introduced and analyzed and the future developments and potential problems of the manipulator trajectory optimization are discussed. Conclusion: The manipulator trajectory planning reduces complicated operator and hard programming tasks, improving the intelligence of robots and the work efficiency. Current researches focus on collision- free, parameter-optimized and high-efficiency solution which can be used to solve the problem of the end-trajectory planning of the manipulator in the complicated space with obstacles. The aspects that need to be improved in the future include: algorithm reliability, operational security and intelligence, human-computer interaction, efficient simulation, and so on. More patents on manipulator trajectory planning should be invented.

2001 ◽  
Vol 6 (3) ◽  
pp. 172-176 ◽  
Author(s):  
Lawrence A. Pervin

David Magnusson has been the most articulate spokesperson for a holistic, systems approach to personality. This paper considers three concepts relevant to a dynamic systems approach to personality: dynamics, systems, and levels. Some of the history of a dynamic view is traced, leading to an emphasis on the need for stressing the interplay among goals. Concepts such as multidetermination, equipotentiality, and equifinality are shown to be important aspects of a systems approach. Finally, attention is drawn to the question of levels of description, analysis, and explanation in a theory of personality. The importance of the issue is emphasized in relation to recent advances in our understanding of biological processes. Integrating such advances into a theory of personality while avoiding the danger of reductionism is a challenge for the future.


Author(s):  
Shuo Zhang ◽  
Shuo Shi ◽  
Tianming Feng ◽  
Xuemai Gu

AbstractAt present, unmanned aerial vehicles (UAVs) have been widely used in communication systems, and the fifth-generation wireless system (5G) has further promoted the vigorous development of them. The trajectory planning of UAV is an important factor that affects the timeliness and completion of missions, especially in scenarios such as emergency communications and post-disaster rescue. In this paper, we consider an emergency communication network where a UAV aims to achieve complete coverage of potential underlaying device-to-device (D2D) users. Trajectory planning issues are grouped into clustering and supplementary phases for optimization. Aiming at trajectory length and sum throughput, two trajectory planning algorithms based on K-means are proposed, respectively. In addition, in order to balance sum throughput with trajectory length, we present a joint evaluation index. Then relying on this index, a third trajectory optimization algorithm is further proposed. Simulation results show the validity of the proposed algorithms which have advantages over the well-known benchmark scheme in terms of trajectory length and sum throughput.


Author(s):  
Artem S. Belousov ◽  
Anton Esipovich ◽  
Evgeny Kanakov ◽  
Ksenia V. Otopkova

Living in the time of the most heighten environmental issues, humanity should take care about the future. Green Chemistry provides a broad range of possibilities for researchers to design of...


2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110346
Author(s):  
Yunyue Zhang ◽  
Zhiyi Sun ◽  
Qianlai Sun ◽  
Yin Wang ◽  
Xiaosong Li ◽  
...  

Due to the fact that intelligent algorithms such as Particle Swarm Optimization (PSO) and Differential Evolution (DE) are susceptible to local optima and the efficiency of solving an optimal solution is low when solving the optimal trajectory, this paper uses the Sequential Quadratic Programming (SQP) algorithm for the optimal trajectory planning of a hydraulic robotic excavator. To achieve high efficiency and stationarity during the operation of the hydraulic robotic excavator, the trade-off between the time and jerk is considered. Cubic splines were used to interpolate in joint space, and the optimal time-jerk trajectory was obtained using the SQP with joint angular velocity, angular acceleration, and jerk as constraints. The optimal angle curves of each joint were obtained, and the optimal time-jerk trajectory planning of the excavator was realized. Experimental results show that the SQP method under the same weight is more efficient in solving the optimal solution and the optimal excavating trajectory is smoother, and each joint can reach the target point with smaller angular velocity, and acceleration change, which avoids the impact of each joint during operation and conserves working time. Finally, the excavator autonomous operation becomes more stable and efficient.


Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1804
Author(s):  
Guangmin Ren ◽  
Hongtao Han ◽  
Yixuan Wang ◽  
Sitong Liu ◽  
Jianyong Zhao ◽  
...  

Photocatalysis holds great promise as an efficient and sustainable oxidation technology for application in wastewater treatment. Rapid progress developing novel materials has propelled photocatalysis to the forefront of sustainable wastewater treatments. This review presents the latest progress on applications of photocatalytic wastewater treatment. Our focus is on strategies for improving performance. Challenges and outlooks in this promising field are also discussed. We hope this review will help researchers design low-cost and high-efficiency photocatalysts for water treatment.


2020 ◽  
Vol 306 ◽  
pp. 123189 ◽  
Author(s):  
Petter Paulsen Thoresen ◽  
Leonidas Matsakas ◽  
Ulrika Rova ◽  
Paul Christakopoulos

Digital Twin ◽  
2021 ◽  
Vol 1 ◽  
pp. 12
Author(s):  
Zhihan Lv ◽  
Shuxuan Xie

Advanced computer technologies such as big data, Artificial Intelligence (AI), cloud computing, digital twins, and edge computing have been applied in various fields as digitalization has progressed. To study the status of the application of digital twins in the combination with AI, this paper classifies the applications and prospects of AI in digital twins by studying the research results of the current published literature. We discuss the application status of digital twins in the four areas of aerospace, intelligent manufacturing in production workshops, unmanned vehicles, and smart city transportation, and we review the current challenges and  topics that need to be looked forward to in the future. It was found that the integration of digital twins and AI has significant effects in aerospace flight detection simulation, failure warning, aircraft assembly, and even unmanned flight. In the virtual simulation test of automobile autonomous driving, it can save 80% of the time and cost, and the same road conditions reduce the parameter scale of the actual vehicle dynamics model and greatly improve the test accuracy. In the intelligent manufacturing of production workshops, the establishment of a virtual workplace environment can provide timely fault warning, extend the service life of the equipment, and ensure the overall workshop operational safety. In smart city traffic, the real road environment is simulated, and traffic accidents are restored, so that the traffic situation is clear and efficient, and urban traffic management can be carried out quickly and accurately. Finally, we looked forward to the future of digital twins and AI, hoping to provide a reference for future research in related fields.


2021 ◽  
Vol 15 ◽  
Author(s):  
Yanling Zhao ◽  
Huanqing Zhang

Background: Bearing testing machine is the key equipment for bearing design, theoretical research and improvement, and it plays an important role in the performance of bearing life, fatigue, vibration and working temperature. With the requirements of aerospace, military equipment, automobile manufacturing and other industrial fields of the bearing are becoming higher and higher. There is an urgent need for high-precision and high-efficiency bearing testing machines to monitor and analyze the performance of bearings. Objective: By analyzing the recent patents, the characteristics and existing problems of the current bearing testing machine are summarized to provide references for the development of bearing test equipment in the future. Methods: This paper reviews various representative patents related to the third generation bearing testing machines. Results: Although the structure of bearing testing machines is different, the main problems in the structure and design principle of bearing testing machine have been summarized and analyzed, and the development of trend and direction of the future bearing testing machine have been discussed. Conclusion: Bearing testing machines for health monitoring of bearing life cycle is of great significance. The current bearing testing machine has basically achieved the monitoring and analysis However, due to the emergence of new types of bearings, further improvement is still needed. With the development of testing technology towards intelligent and big data-driven direction, bearing testing machine is moving towards the type of cloud computing and large-scale testing.


Galaxies ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 100 ◽  
Author(s):  
Karen Olsen ◽  
Andrea Pallottini ◽  
Aida Wofford ◽  
Marios Chatzikos ◽  
Mitchell Revalski ◽  
...  

Modeling emission lines from the millimeter to the UV and producing synthetic spectra is crucial for a good understanding of observations, yet it is an art filled with hazards. This is the proceedings of “Walking the Line”, a 3-day conference held in 2018 that brought together scientists working on different aspects of emission line simulations, in order to share knowledge and discuss the methodology. Emission lines across the spectrum from the millimeter to the UV were discussed, with most of the focus on the interstellar medium, but also some topics on the circumgalactic medium. The most important quality of a useful model is a good synergy with observations and experiments. Challenges in simulating line emission are identified, some of which are already being worked upon, and others that must be addressed in the future for models to agree with observations. Recent advances in several areas aiming at achieving that synergy are summarized here, from micro-physical to galactic and circum-galactic scale.


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