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Picking robots have been widely used for citrus harvesting in recent years. However, the rest citrus during continuous picking can be irregularly disturbed by the wind, robot force, and the load weight of bearing branches under the natural environment. The citrus in the disturbed state cannot be rapidly and accurately detected, and then localized online, leading to the low efficiency of automatic robotic picking. In this study, online target detection and rapid localization were proposed using improved YOLOv5s+DeepSORT. The position of citrus at rest was predicted using the motion-tracking trajectory of disturbed citrus within a short period of time. The coordinates of the citrus were then obtained rapidly. Firstly, the CBAM (Convolutional Block Attention Module) attention mechanism was added to the YOLOv5s network, in order to detect the small and occluded targets. The SIoU loss function was used to enhance the direction matching between the prediction and the calibration frame, in order to improve the convergence speed of regression. Secondly, the target re-identification network was improved in the DeepSORT more suitable for the feature extraction of citrus targets. The feature extraction of the network was enhanced to improve the tracking performance on the disturbed citrus; The Count counter was used to accumulate the number of tracking frames in each citrus for an optimal target. Since the disturbance of the rest citrus was progressively propagated over time, the localization prediction and picking were only for targets with optimal tracking trajectories at a time. The real-time updating was realized in real time. Finally, the values of the depth camera were combined within the critical distance range, excluding the influence of background citrus on the detection speed. The number of tracking targets each time was limited to effectively improve the tracking speed of disturbed citrus. The experimental results show that the P (precision) and mAP (average detection accuracy) of improved YOLOv5s were improved by 3.9 and 1.1 percentage points, respectively, with a detection rate of 69.3 frames per second. The MOTA (Multi-Object Tracking Accuracy) and MOTP (Multi-Object Tracking Precision) of the improved DeepSORT were improved by 9.2 and 5.4 percentage points, respectively, whereas, the average number of ID (identity) switching times of targets was reduced by 32 times. Grasping experiments were conducted in the laboratory, in which the citrus was randomly swung along different orientations with an amplitude of about 10 cm. When the predicted localization time was 1, 2, 3, 5, 7, and 10 s, the average precision values of disturbed citrus localization were 21.3%, 53.0%, 81.9%, 83.7%, 86.1%, and 94.9%, respectively. The citrus picking test was conducted with the citrus localization time of 3 s. The average grabbing time for each citrus was 12.8 s, which was 5.6 s shorter than that without the optimization. The efficiency was improved by 30.4%. This finding can provide technical support and references for citrus picking in disturbed states. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central China Normal University is the property of Huazhong Normal University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In 20th-century science fiction, robotic images have already had "gender" characteristics. Through the in-depth analysis of Asimov's story collection I, Robot, this paper reveals the gendered process and identity construction mechanism of robots in its narrative. The fixed mode of human-machine relationship leads to the fact that there is a power relationship between men, women and robots, which is embodied in the two gender schemas: human "Adam" - Robot "Eve" and "Masquerade" woman - Robot "Bride". With the displacement of the power subject in different situations, the gender of the robot also changes, showing the characteristics of fluidity, discontinuity and paradox. It should be emphasized that the gender writing of sci-fi narratives is not intended to promote a discourse of power in the paradigm of anthropocentrism, but rather as a metaphor or an allegory for reflecting on humanity. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: Traditional rehabilitation training has limited potential to improve functional recovery from chronic injuries. Increasing attentions have been paid to the application of rehabilitation robots in rehabilitation training of chronic injuries. OBJECTIVE: To analyze and track the hot spots and frontiers of related research in the field of rehabilitation robot in the past 10 years, thereby providing some guidance for future research. METHODS: The literatures regarding rehabilitation robots published from 2010 to 2020 were retrieved in the Web of Science core database by computer. Search strategy was TS=(rehabilitation robot OR rehabilitation robotics). CiteSpace 5.7 visualization software was used to analyze the hot spots and frontiers of rehabilitation robot research from the aspects of high-influence countries/regions, institutions, authors, high-frequency keywords and burst words. RESULTS AND CONCLUSION: A total of 3 194 literatures were included. In recent years, the research on rehabilitation robots has been growing steadily. The number of relevant literatures published annually shows a steady increase trend. The number of articles published by the United States ranks first, followed by China. Northwestern University in the United States ranks first with 161 articles published. Professor Riener R, from the University of Zurich, Switzerland, has published 48 articles, ranking the first among the authors. Nine representative keyword clusters have formed, and the research emphasis and direction change over time. In recent 10 years, the relevant research focuses on intelligent control of rehabilitation robots, task analysis and learning, performance and reliability, and how to realize the natural and accurate interaction between robot and human through the integration of machine intelligence and biological intelligence. At present, rehabilitation robots are the most widely used in the field of upper limb and nerve injuries, and the interest in brain-machine interface, virtual reality, flexible wearable, task analysis and the exoskeletons has increased in the research of rehabilitation robot, which are the frontiers and hot issues in recent years, representing the development trend of future studies, and referring to the future research direction. Future research in the field of rehabilitation robots should focus on the following aspects: First, focus on the functional needs of patients to improve the quality of life. Secondly, strengthen multidisciplinary cooperation and build a cooperation network among regional countries. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Jilin University (Science Edition) / Jilin Daxue Xuebao (Lixue Ban) is the property of Zhongguo Xue shu qi Kan (Guang Pan Ban) Dian zi Za zhi She and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Tunnel Construction / Suidao Jianshe (Zhong-Yingwen Ban) is the property of Tunnel Construction Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aiming at the problem that the local path planning algorithm is only applicable to single-vehicle robots, this paper proposed a dynamic window algorithm for trailer-type mobile robots. Firstly, it used the equation of multi-vehicle structure to realize the motion control of the trailer mobile robot. Then, it used the evaluation function to evaluate both the tractor and the trailer and add them according to the weights. Finally, for the structural characteristics of the trailer, it added the angle constraint between the tractor and the trailer during the movement to ensure the stability of the motion track. The simulation experiments show that the motion control of the trailer-type mobile robot can satisfy the convergence. At the same time, the proposed algorithm realized the task of the local path planning of the trailer-type mobile robot, and the variation of the angle was beyond the limit during the motion. This research has great reference value for the autonomous navigation of trailer-type mobile robots. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chongqing University of Posts & Telecommunications (Natural Science Edition) is the property of Chongqing University of Posts & Telecommunications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The reliability method was introduced into the prediction of modal coupling chatter in robotic milling. Firstly， the reliability model was established and the limit state equation was obtained. Secondly， the fourth-order moment method was used to calculate the reliability and sensitivity to analyze the influence of various parameters on the milling stability. Finally， an example was given based on the engineering background of robotic milling bone. The results showed that the two-degree-freedom stiffness， cutting force coefficient and feeding direction of the robot will affect the stability of the milling process. Within a certain range， increasing the stiffness in X divection，reducing the stiffness in Y direction， reducing the cutting force coefticient and choosing the feed divection resonably are helpful to avoiding modal coupling chatter. The system is more sensitive to the change of cutting force coefficients than to the stiffness in X and Y directions， and has more significant benefit influence on stability. [ABSTRACT FROM AUTHOR]

As the world's biggest robot soccer match with the highest level and the widest influence, RoboCup (Robot Soccer World Cup) is held to promote researches on artificial intelligence and robotics. RoboCup 2D match provides an excellent emulational platform, which is both appropriate for students to compete in science and technology, and suitable for researching on artificial intelligence theory. Firstly, the system framework of RoboCup 2D including the overall framework, the server framework and the client framework are introduced. Secondly, based on example team agent2d, planning model of DreamWing2D soccer team is designed and implemented. Lastly, the setup and experimental approaches of RoboCup 2D platform are demonstrated. The team specially improved in planning model performs much better and has achieved good results in RoboCup China Open. [ABSTRACT FROM AUTHOR]

The omnidirectional walking robot with a steering-wheel synthesizes the mechanism features of legged robot and vehicle's steering wheel. To investigate the kinematic characteristics and motion control systematically, the design idea, mechanism features and kinematics principle of the robot are introduced. Then an equivalent manipulator model is built, the Jacobian of the manipulator is given and dynamics both in joint space and Cartesian space are developed, the resulting nonlinear closed-loop control system can be obtained based on the formulated dynamics equations. The co-simulation PID control of omnidirectional motion is implemented based on ADAMS and Matlab/Simulink, the experiments on the prototype is performed. The simulation and experiments validate that the robot with a steering wheel can be manipulated flexibly and accurately in omnidirectional motion, and the control method is simple and reliable. [ABSTRACT FROM AUTHOR]

Continuum robot is a new class of biologically inspired robot. Based on the developed snake-like colonoscope robotic prototype, we use the motion simulation module for motion analysis of the snake-like colonoscope robot single joint and accomplish the analysis of interference experiment between the gimbal ring based on Pro/E. Finally, structure design feasibility of the snake-like colonoscope robot is verified. [ABSTRACT FROM AUTHOR]

The problem of trajectory tracking of a two-link free-floating flexible space robot is concerned in this paper. The dynamic equations of the robot are firstly developed by using Lagrangeg principle with elastic vibration; and then they are transformed into a fully controllable form with the flexible vibration disturbance for the purpose of controller synthesis. By this simplified model, a robust control approach using adaptive non-singular terminal sliding mode is developed, in which the dynamic uncertainty and disturbance can be eliminated via the online updating law, and the associated Lyapunov stability analysis are also investigated. Numerical simulation results show that the sliding mode is modified by adding a conditional integral to reduce the stable error in the present of attitude disturbance of a spacecraft. [ABSTRACT FROM AUTHOR]

For the local path planning of single robot, two new concepts, optimal way representative point and dangerous wall representative point, are defined for path optimization and obstacle- avoidance. A new attraction moment function to make robot' s principal motion direction line (PMDline) face to the present optimal way representative point in general and a new repulsion moment function to make robot's PMDline away to the corresponding dangerous wall representative point are designed. Then, a motion controller is designed based on the two artificial moments. As the controller will make robot move along its PMDline with its longest step length when the line segment between robot and target is blocked by obstacles, robot will not be trapped even in complicated environments. The algorithm for optimal way representative points, the general steps for the path planning and a simulation are also given. The simulation results indicate that the proposed method is of feasibility and validity. [ABSTRACT FROM AUTHOR]

Aiming at the special motion (position and posture adjustment) of the head link of a new mine rescue robot, a novel algorithm based on the combination of spatial decomposition and genetic algorithm (GA) was proposed to solve inverse kinematics of the robot. This algorithm can realize prospective position and posture with the lowest turning cost and keep the robot stable. The two-step spatial decomposition method is presented and it overcomes the defects of big searching space and not converging to the global optimum solution using a GA algorithm. Simulation results show that the position and posture error derived using the new algorithm is smaller and the joint angles are closer to real values. The new algorithm can satisfy the motion requirement of head link of the new mine rescue robot. [ABSTRACT FROM AUTHOR]

This paper aims at reducing the cost of measurement period and solving the problem of contradiction between large range and small blind zone in ultrasonic distance measurement, when mobile robot detects the obstacle. A controllable ultrasonic distance measurement system with a multi-range adaptive strategy based on Kalman filter is designed. By using the estimated values from Kalman filtering, the system accomplishes the range adaptation and the measurement parameters of the system are automatically adjusted. The experimental results show that this method has reduced the blind zone and expanded the dynamic measurement range of the system, meanwhile achieved an accurate estimate of the dynamic parameters of the target. Furthermore, the proposed scheme has cut down the average cost of measurement period and enhanced real-time capability. [ABSTRACT FROM AUTHOR]

To realize the stable walking cycle of passive biped robot, this paper presents a method to find the fixed point and a detailed analysis on the effect of the change of mechanical parameters of the passive walking model and slope gradient on the existence of stable fixed point is' carried out. The effect for each parameter at the given initial conditions on the speed of converging to the stable cycle walking and the effect of changing status of stable fixed point from the change of the parameters are investigated. It is concluded that the smaller mass for legs, a higher location for the center of mass, the right radius of foot, the larger moment of inertia as well as the right slope gradient are beneficial for improving the local stability of the passive robot. [ABSTRACT FROM AUTHOR]

Using Lagrange equation and other mechanics methods, this paper analyzes the motion characteristics of rolling and turning of a micro-spherical robot, and achieves the conditions of jumping. A general dynamics model is built based on the analysis of characteristics of precession, which can make the robot roll along any curve. A virtual prototype of the spherical robot is developed, and the motion simulation is conducted. The result verifies the correctness of above analysis. The work in this paper establishes the foundation for further research on nonlinear control of spherical robot. [ABSTRACT FROM AUTHOR]

For a better understanding of the essential characteristics of passive robot, making the research of model be a better guide to the design of actual prototype, methods of numerical simulation and verification of Adams were employed to research a two-dimensional pure passive walking model with round feet. Characteristics of the passive model were analyzed and the dynamic equations were derived with Lagrange Equation. Based on the phenomenon of dynamics of symmetric gait of the robot appearing to be a limit cycle in the phase space, a complete process of the simulation of steady-walking of this model was given with Matlab tool and the initial conditions of the steady-walking model were achieved. The dynamics and characteristics in each stage of the biped locomotion cycle were discussed. Adams was used to verify the simulation. This study will be the basis of stability analysis of the robot and a guide to the design of a passive robot prototype. [ABSTRACT FROM AUTHOR]

Several remote control modes and a layered architecture for teleoperation of space robot (LATSB) are designed aiming at the characteristic of space robot. A teleoperation system for space robot is developed, which is comprised of five subsystems: the task planning subsystem, the master-slave control subsystem, the predictive simulation subsystem, the information processing subsystem and the ground-based validation subsystem. Experimental results verify the functionality and performance of the system and its subsystems. The flexible operation interface of the system provides simple user interface for general users, and the low -- level control capability for roboticists. [ABSTRACT FROM AUTHOR]

Propese a real-time workflow time modeling and verification method based on timed automata. First, trans-form timed workflow digrams to timed automata model, and then verify the time constrains via using the mechanism of timed automata. [ABSTRACT FROM AUTHOR]

A suspension system for studying the characteristics of space robots working under microgravity condition and its gravity compensation are introduced. After modeling the dynamic characteristics of suspension module, the optimal control parameters are solved by numerical computation and simulation based on nonlinear programming. The result is verified through orthogonal tests for optimization aimed at precision and time optimization control. As a result of this study, an optimal precision tracking control scheme is gained for space robot test system to simulate the microgravity environment. [ABSTRACT FROM AUTHOR]

The characteristics of the path planning of free-floating space robot are introduced and the key problems in the research are summarized. The main achievements in the non-holonomie path planning, Cartesian path planning and autonomous path planning for target capturing are addressed. And the application scopes, advantages and disadvantages of each method are discussed. Finally, the research prospects of the path planning of space robot are presented. [ABSTRACT FROM AUTHOR]

The problem of how to accurately segment the full vision images caught by robots is investigated. First over-segmentation of full vision images based on color features in HSV color space is performed. Then by taking into account the fact that texture features are not sensitive to illumination changes, the regions which have been over-segmented are merged after the texture features are extracted via Fourier transform. It is demonstrated that the proposed method can achieve full-image segmentation and is of higher precision and reliability than simply using the color or texture features. [ABSTRACT FROM AUTHOR]

A leg-wheeled passive wheel type of biped ice-skater robot was designed on the basis of rolling and skating principle in this paper. The kinematic analysis on it was carried out by Denavit-Hartenberg (D-H) method. The robots legs were classified into supporting leg and swing leg. Assumed that the static frictional force in the normal direction of four wheels on the swing leg was in critical condition, three kinds of stability criteria taking the kinematic constraints of the wheel and the balance of the body into account were discussed depending on the state between the wheels and the plane. The validity and feasibility of the stability criterion were verified by simulations and experiments on the robot. [ABSTRACT FROM AUTHOR]

To better perform an overall evaluation on the selection of robot design, a new method was proposed based on the combination of analytic hierarchy process (AHP) and fuzzy theory. In this method, the factor weights were calculated through the fuzzy extent model of AHP, and the value of single factor was evaluated with trigonometrical fuzzy number. Then the overall evaluation on robot design was conducted with hierarchical structures, and the result of robot design selection was obtained. The feasibility of this method was validated by an example of humanoid-robot selection. [ABSTRACT FROM AUTHOR]

This paper presents an error modeling methodology that enables the tolerance design and kinematic calibration of a class of parallel kinematic machines with parallelogram struts to be integrated into a unified framework. The error mapping function is formulated to identify the source errors affecting the uncompensable pose errors. The sensitivity analysis is also carried out to investigate the influences of source errors on the pose accuracy. This study provides references for the design and manufacture of machines with similar structure. [ABSTRACT FROM AUTHOR]

Taking track programming mathematical models of "mud puncturing dragon" robot as computer simulation models, the simulation of moving process of "mud puncturing dragon" robot by means of computer was studied, A number of simulation programs were programmed and some better simulation results were gotten. By running the simulation programs, the moving process of "mud puncturing dragon" robot can be observed directly. On the basis of above work, kinematics and dynamics simulation of "mud puncturing dragon" robot can be studied. Meanwhile, this research is beneficial to the design improvement of both the model machine and the practical machine of "mud puncturing dragon" robot, and to the application analysis of the robot as well. [ABSTRACT FROM AUTHOR]

For improving start-up performance of propeller-type underwater robot, the oscillating mode of herbivorous fish was designed as a prototype of fish-like robot with high maneuverability. Following the motion analysis with high-speed photograph of crucian's C-start, kinematic equations of fish-like robot C-start were established. Through calculation of the lateral oscillation of fish body, the tailing vortex, the boundary layer friction and the added mass at lengthwise direction, a dynamic model was acquired. Laws of motion of body centerline and multi-gait simulating experiments displayed kinematic and dynamic parameters of fast-start performance, and optimum designs of fish-like robot for higher acceleration. The educed conclusions from numerical simulation accord with swimming rules of fish basically, which provides the theoretical foundation and feasible design scheme for developing underwater robot with fast-start performance. [ABSTRACT FROM AUTHOR]

The joints of multi-arm robot were simplified into entities, each of which consists of a cylinder and two hemispheres jointed at two ends of cylinder respectively (radius of cylinder is equal to radius of hemisphere). For 2 entities in arbitrary situation, graph transform was conducted. One of them was transformed into vertical state and the center of underside circle of cylinder for the entity coincides with the origin of 3-D right-angled coordinate system after graph transform. Afterwards, according to the theory of solid analytic geometry and the interferences of orthographic projections of 2 entities on coordinate plane, 5 possible cases in which two entities in 3-D space don't interfere with each other are found out and corresponding judgment conditions are given Out. Finally, an approach is presented to detect collision between the joints. Numerical experiments show that average detection speed of the method is faster than that of previous related algorithms. [ABSTRACT FROM AUTHOR]