In this article, the trajectory planning of the two manipulators of the dual-arm robot is studied to approach the patient in a complex environment with deep reinforcement learning algorithms. The shape of the human body and bed is complex which may lead to the collision between the human and the robot. Because the sparse reward the robot obtains from the environment may not support the robot to accomplish the task, a neural network is trained to control the manipulators of the robot to prepare to hold the patient up by using a proximal policy optimization algorithm with a continuous reward function. Firstly, considering the realistic scene, the 3D simulation environment is built to conduct the research. Secondly, inspired by the idea of the artificial potential field, a new reward and punishment function was proposed to help the robot obtain enough rewards to explore the environment. The function is consisting of four parts which include the reward guidance function, collision detection, obstacle avoidance function, and time function. Where the reward guidance function is used to guide the robot to approach the targets to hold the patient, the collision detection and obstacle avoidance function are complementary to each other and are used to avoid obstacles, and the time function is used to reduce the number of training episode. Finally, after the robot is trained to reach the targets, the training results are analyzed. Compared with the DDPG algorithm, the PPO algorithm reduces about 4 million steps for training to converge. Moreover, compared with the other reward and punishment functions, the function used in this paper will obtain many more rewards at the same training time. Apart from that, it will take much less time to converge, and the episode length will be shorter; so, the advantage of the algorithm used in this paper is verified.
A treetop trail is an elevated linear green open space that plays a key role in forming a scientifically rational urban space and meeting the growing leisure needs of the people. Taking the Mountains-to-Sea Trail in Xiamen, China as a case, and through 426 questionnaires, this study explores the dimensions of the perceived restorative environment components of greenway recreationists and impacts on behavioral intentions. The demographic factors lead us to the following three conclusions. First, from an age perspective, restorative environmental perceptions are strongest among those aged 60 and above and weakest among those aged 18–30. Second, in terms of place of permanent residence, local visitors have stronger restorative environmental perceptions than other city users. Third, in relation to the number of accompanying travelers, individuals who embark on solo journeys experience the most robust perception, while that diminishes as the count reaches three or more companions. A structural equation model (SEM) is used to present the quantitative relationship among avoidance motivation, treetop trail environmental quality, restorative environmental perception, place attachment, and loyalty. The results showed that users’ escape motivation has a direct and indirect positive correlation with restorative environmental perceptions, and environmental perceptions have a significant positive correlation with restorative environmental perceptions. Furthermore, their place attachment to the restorative nature of the treetop trails positively affected their loyalty. This study provides essential factors to consider when constructing treetop trails in high-density cities.
Purpose When the mobile manipulator is traveling on an unconstructed terrain, the external disturbance is generated. The load on the end of the mobile manipulator will be affected strictly by the disturbance. The purpose of this paper is to reject the disturbance and keep the end effector in a stable pose all the time, a control method is proposed for the onboard manipulator. Design/methodology/approach In this paper, the kinematics and dynamics models of the end pose stability control system for the tracked robot are built. Through the guidance of this model information, the control framework based on active disturbance rejection control (ADRC) is designed, which keeps the attitude of the end of the manipulator stable in the pitch, roll and yaw direction. Meanwhile, the control algorithm is operated with cloud computing because the research object, the rescue robot, aims to be lightweight and execute work with remote manipulation. Findings The challenging simulation experiments demonstrate that the methodology can achieve valid stability control performance in the challenging terrain road in terms of robustness and real-time. Originality/value This research facilitates the stable posture control of the end-effector of the mobile manipulator and maintains it in a suitable stable operating environment. The entire system can normally work even in dynamic disturbance scenarios and uncertain nonlinear modeling. Furthermore, an example is given to guide the parameter tuning of ADRC by using model information and estimate the unknown internal modeling uncertainty, which is difficult to be modeled or identified.
As a significant component of rural settlements, residential architecture is a record of historical changes containing considerable research value. In the study of residential architectural continuity, the focus is on the inheritance and innovation of traditional residential architectural “genes” in contemporary new residential buildings. Based on a systematic review of the literature, the purpose of this study is to analyze the research trends, categories, and variables relating to architectural continuity in residential buildings, and to build a systematic and comprehensive framework for assessing the architectural continuity of residential buildings in rural settlements based on prior research. This study provides guidance and references for evaluating the design of new residential buildings in rural settlements and for formulating regional planning principles. Using the PRISMA guidelines as the basis for the review method, we filtered the literature from three databases: Web of Science (WoS), Scopus, and EI, and studied the 40 articles selected at the end. As can be seen from the results, the literature on architectural continuity in rural settlements has focused more on functional and typological levels and less on the archetypal level of architectural continuity (user behavior). Still, the archetypal level is the most important, because the behavior of housing users directly influences the degree to which housing is continuous in terms of its function and type. The most important finding of this review is that the resident behavior of housing users has a significant influence on the assessment of the continuity of housing architecture, and thus, the continuity of housing architecture in rural settlements must be assessed in conjunction with user behavior.
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