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Copyright of Experimental Technology & Management is the property of Experimental Technology & Management 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 Experimental Technology & Management is the property of Experimental Technology & Management 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 Control Theory & Applications / Kongzhi Lilun Yu Yinyong is the property of Editorial Department of Control Theory & Applications 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 problems of large sampling area, small effective area, many redundant nodes and long pruning time when applying rapidly exploring random trees (RRT) algorithm to manipulator path planning, this paper proposed an efficient RRT path planning algorithm based on partitioned dynamic sampling strategy and repeated area node rejection mechanism. Firstly, this paper used PS-RRT to quickly plan the initial path of the manipulator end. Secondly, it detected the collision of the links when the manipulator followed the path in sections, and carried out the secondary planning of the collision section with arm constraints. Finally, it spliced the initial path and the second planned path, and then pruned the path. The simulation results show that the obstacle avoidance path planning strategy of the manipulator based on PS-RRT algorithm greatly reduces the number of invalid nodes and can efficiently plan the collision free path of the manipulator, which verifies the feasibility of the algorithm. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chongqing University of Technology (Natural Science) is the property of Chongqing University of Technology 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 Control Theory & Applications / Kongzhi Lilun Yu Yinyong is the property of Editorial Department of Control Theory & Applications 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 Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering 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 this paper an impedance composite control method based on disturbance observer is proposed for manipulator system with unknown disturbances. For tracking the second order impedance dynamic model a composite control strategy is designed,which includes the disturbance observer (DOB),the impedance controller, and the position controller to estimate unknown disturbances, correct input angle, and track the adjusted angle, respectively. This composite control strategy ensures that the impedance error converges to a small neighborhood, thus realizes the desired dynamic tracking of the second order impedance model. The effectiveness of the proposed control method is proved by simulation examples. [ABSTRACT FROM AUTHOR]

This paper designs a small one and conducts its kinematic study in three working positions. At present, the rigid-flexible coupling analysis of a manipulator is mostly the joint simulation of ANSYS software and ADAMS software, where a modal file of the flexible body is created in ANSYS software to use the bidirectional data exchange interface of ADAMS software to realize rigid-flexible coupling dynamics analysis. However, with continuous updating and iteration of the software, this analysis process can be realized in the transient dynamics analysis module Transient Structural configured in Workbench software, the simulation platform of ANSYS. SolidWorks software is used to design the model of the manipulator. Meanwhile, ANSYS software is used to simulate the statics and the rigid-flexible coupling dynamics of the manipulator. The experimental results show that the static rigidity analysis has a great influence on the accuracy of the results, and it is further concluded that the maximum equivalent stress analysis cannot accurately judge the safety of the structure. The simulation results of the rigid-flexible coupling show that, in three different positions, the maximum stress value of the large arm of the manipulator is 82.941 MPa, and the maximum moving speed of the large arm is 2.455 1 m/s. At the same time, the manipulator is also capable of reaching the maximum working range of 1372.7 mm. The transient dynamics motion simulation by ANSYS can effectively predict motion patterns and stress distribution of the manipulator, and make further calculation of the service life of the manipulator. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering 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 Coal Science & Technology (0253-2336) is the property of Coal Science & Technology 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 Journal Of Sichuan University (Natural Sciences Division) / Sichuan Daxue Xuebao-Ziran Kexueban is the property of Editorial Department of Journal of Sichuan University Natural Science Edition 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.)

Nowadays,domestic main aircraft and satellites fabrication are still using artificial assembly. Old-fashion assembly technology and low robot absolute position accuracy problems are difficult to satisfy the requirement of high precision,high performance of aircraft and satellite. It hinders the development of industrial robots in aviation manufacturing industry. Thus in the process of robot flexible automated assembly,how to improve the mechanical manipulator absolute positioning accuracy calibration technology has become wide focus on academia and industry. In order to systematically analyze and summarize the existing research results,this paper discussed absolute positioning accuracy calibration methods. It summarized the research status of the mechanical arm calibration technology at home and abroad. It analysed key technologies such as the error of uncertainty,elimination of redundant parameters and the optimal measuring structure selectivity. This paper conceived and looked to the future development trends of manipulator absolute positioning accuracy calibration technique. [ABSTRACT FROM AUTHOR]

It is difficult to establish Jacobian matrix and determine the coordinate frames of links for non-standard actuator. A new analytical method to establish the Jacobian matrix and determine the coordinate frames for joints and links are proposed in this paper. The proposed method made the positioning analysis of end-effector easier in space. At the same time, it is necessary to prove the effectiveness of the proposed method theoretically and verify the localization and configuration capabilities through simulations. First of all, forward kinematics model was set up based on a non-standard five Degree Of Freedom (5-DOF) actuator. A frame transformation is performed from base coordinate to end-effector coordinate. The relation between two adjacent joints is defined by a homogenous pose matrix. Secondly, the necessary and sufficient conditions for comprehensive localization are derived. They can guide the actuator to perform various tasks, such as tracking, assembly and autonomous grasping. A 5-DOF actuator is considered here as an example and this holds good for any N-DOF. Thirdly, inverse kinematics solutions are obtained by using artificial Neural Network (NN) based on back-propagation Multi-Layer Perceptron (MLP, multilayer perceptron NN) and are not unique. A unique solution using nonlinear minimization optimization is found. A NN based on supervisory learning method including three inputs, twenty neurons and five outputs has been used. Excitation function tansigmoid and linear excitation function pureline are in hidden and outer layers respectively. In Cartesian coordinate space, NN is trained by means of Levenberg Marquardt (LM) algorithm. The training sets used are Denav Hartenberg (DH) parameters and Cartesian coordinates. The weights are updated continuously which reduces the Mean Square Error (MSE) gradually. When MSE reaches the threshold set up, NN training will be terminated. After training, the test sets are used to examine the capability of NN. Fourthly, there are two evaluation functions viz., localization and cost functions. The localization function is defined to evaluate the positioning property of end-effector. At the same time, in task space, it will check whether the actuator has reached the target point along the direction needed or not. The cost function is defined to evaluate the kinematics configuration. There is a great relevance between cost function and Jacobian matrix. Velocity mapping from each joint to the end-effector was described by Jacobian matrix. So the cost function could give expression for kinematic configuration. At the end, simulations and experiments are conducted. The settings include industrial computer UNO2184G, 5-DOF non-standard actuator, Windows 7, MATLAB2012a. Coordinate frames for each joint are established and D-H parameters are determined. Then relative pose matrix is obtained between each of the two adjacent joints. Initial end-effector pose is obtained following right multiplication rule. The end-effector space range is formed under each joint operation range. Then, simulation is performed using NN, obtained localization and cost functions. The following results are obtained. The rank of Jacobian matrix is equal to 5. Therefore, this actuator met necessary and sufficient conditions for comprehensive positioning. NN method for solving inverse kinematics has reduced the computational complexity compared to conventional method. There are 21 groups of solutions when positioning to (41.4, 89.0, 104.5). The optimal solution obtained is (21.61, 91.44, 135.52, 221.42, 0) according to localization function rule. The optimal solution obtained according to cost function rule is (21.61, 125.73, 108.42, 221.99.41, 0). NN accuracy is 89.9% (approximately) while conventional method is 87.5%. By approximate estimation, the errors for θ1, θ2, θ3, θ4 and θ5 are 3.7°, 3.1°, 3.5°, 3.3°and 4.5°respectively. NN used 1. 2 seconds while conventional method completed in 0.9 seconds. Therefore, computation accuracy has improved by 20% and efficiency by 2.4%. If the system is linear, the conventional method is chosen when less demand in real-time. In contrast, if the system is nonlinear, new method proposed in this paper is chosen when more demand in real-time. The minimum value of localization function is 0.96. The maximum value of cost function is 4.0349×1014. These two parameters decide the comprehensive positioning and the kinematics configuration. From the results presented, it can be concluded that the non-standard actuator with MLP has better localization and optimal configuration. [ABSTRACT FROM AUTHOR]

At present, in the research of transplanting machinery domestic and abroad, the link of pick-up plug seedlings is the bottleneck restricting the development of automatic transplanting machines. This research of test is focused on identifying whether the proposed influencing factors changes have significant impact on the soil matrix intact rate of manipulator pick-up plug seedlings. Tested influencing factors include 3 parts, i.e. soil moisture content, shape features of manipulator structures of pick-up plug seedlings and performance improvement of root system on soil matrix shear strength in the seedling stage. Among them, soil moisture content is from 35% to 65%, and water is mixed with the soil matrix to fill the matrix pore, which increases matrix compressive ability and improves the viscosity of soil inside, at the same time also affects the adhesion force between soil matrix and plug wall. Shape features of manipulator structures of pick-up plug seedlings contain finger-shaped, tongue-shaped and u-shaped, and with these 3 shapes the manipulator contacts with the soil matrix using contact type of line, plane, and closed profile line respectively. Research shows that the root system on soil matrix weaving, winding, reticular surround and twisting force between root system and matrix particles have a significant influence on soil shear strength. In this paper, the performance improvement of root system on soil matrix shear strength is tested in the seedling stage. And the soil matrix intact rate of seedlings is taken as test index. Through the test, the change rule that compression degree determines the compression quantity of pick-up plug seedlings manipulators with different structures is as follows: The force applied on soil matrix by finger-shaped manipulator is concentrated on a few lines, and there is strong pressure on the soil matrix under the same drawing force, so it has a big compression quantity and a big clamping quantity; The tongue-shaped has a large area and weak pressure on the soil matrix, so it needs a small clamping quantity; The U-shaped is also linear contact, but because its lower end is closed, which plays a role of holding up in the process of ascension, the clamping quantity is also small. At the same time, the compression quantity is reduced with the moisture content. Our test adopts the orthogonal experiment design, and chooses L9(34) orthogonal table; with the soil matrix intact rate of seedling as test index, through the analysis of variance and range, we obtain the primary and secondary influencing factors which affect pick-up plug seedlings, and also obtain the optimal level. Meanwhile, the causes are analyzed and a better environment in pick-up plug seedlings is proposed. The results of test show that the shape feature of manipulator structures of pick-up plug seedlings is the primary factor which obviously influences the effect of pick-up plug seedlings manipulator and determines the u-shaped structure is the best. For the moisture content, around 50% is the best. When the first pair of leaves of the seedlings grow up to pick-up plug seedlings, the performance improvement of root system on soil matrix shear strength in the seedling stage has little effect on soil reinforcement. The verification test is carried out, and the results show when the soil moisture content is 50%, the u-shaped manipulator of pick-up plug seedling can make the soil intact rate of seedling all above 80% and seedlings survival quickly, which proves that the selected factors' levels are reasonable. This test determines the key technical points for further study and improving the equipment of pick-up plug seedlings, so it establishes the important theoretical basis for exploring automatic transplanting for pick-up plug seedlings. [ABSTRACT FROM AUTHOR]

In order to ensure the path continuity of redundant manipulators with constrained motion planning, this paper proposed a rapidly exploring random trees algorithm with progressive constraint extension ( PCE-RRT) for the constrained failure and path failure problems of direct interpolation and continuous interpolation. The algorithm introduced a progressive constrained extension method when performing tree expansion, which used the inverse kinematics method with the nearest point information, iteratively shortened the distance between the nearest point and the extended point while ensuring the task constraint, so that each extension could guarantee the constraint and continuity of the tree. PCE-RRT could make the final tree fit well into the constrained manifold subspace, and any two connected nodes in the search tree could satisfy the continuous condition. The simulation experiments verify the validity of the algorithm, and the results show that the proposed algorithm can provide a path solution that satisfied the constraints and continuity conditions for the manipulator constrained motion planning problem. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin University of Science & Technology is the property of Journal of Harbin University of Science & Technology 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 order to improve the tracking efficiency of manipulator tracking dynamic target,this paper proposed a fast tracking strategy of uncalibrated visual servo systems. On the one hand,by predicting the joint angle of the manipulator motion,the controller’s calculating behavior can be carried out in parallel with the manipulator’s moving behavior. On the other hand,the strategy uses the latest image information to calculate the joint angle,which improves the real-time performance of the system. In the simulation and physical experiments,two uncalibrated visual servo systems with different tracking strategy algorithms are constructed to track dynamic target.Finally,the fast, real-time and anti-jamming performance of the strategy are verified by comparing tracking time and tracking path. [ABSTRACT FROM AUTHOR]

In this paper, the model of a self-designed 6-DOF manipulator was established by utilizing standard DH ( Denavit-Hartenberg) rules, and the kinematics solutions were obtained. For the inverse kinematics, according to the structural characteristic that the first three joint axes are intersected at one point, the arm was decoupled into first three and last three joint variables based on an inverse decoupling mechanism. Then the complete 8 analytic solutions were obtained when the arm was under nonsingular configuration. In the process of computing forward and inverse kinematics solutions, intermediate variables were used to substitute homogeneous matrices multiplication to reduce the running time. Finally, computer simulations were carried out for the kinematics algorithms and workspace, the results verify the effectiveness of algorithms and the feasibility of this mechanical structure, and provide prerequisite for the manipulator motion planning and real-time control. [ABSTRACT FROM AUTHOR]

Copyright of Computer Measurement & Control is the property of Magazine Agency of Computer Measurement & Control 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.)

According to the problems of long time consumption, high labor intensity and low degree of mechanization in the tripping process of coal mine tunnel drilling rig, a fast tripping device for coal mine tunnel drilling rig is developed. The paper introduces the scheme formulation of rapid tripping device, and describes in detail the design process of clamping support device, hoisting device and drill pipe frame. The process flow of fast tripping out and fast tripping in is briefly described. In the industrial test, the total tripping footage of the fast tripping device is 15 624 m. The tripping speed is about 3.3 times that of a single drill pipe. The device has reliable performance, stability and high efficiency, and meets the functional requirements of rapid tripping in the process of drilling construction.

According to the characteristics of large-diameter drill pipe, such as large volume, heavy weight and large quantity used in the drilling process, a large-diameter drill pipe loading and unloading device for coal mine tunnel drilling rig was developed. The paper introduces the scheme formulation of large-diameter drill pipe loading rod device, and describes the design process of manipulator, drill pipe bracket, drill pipe bundle and hoisting unit. In order to improve the efficiency of unloading drill pipe, the rod rubbing device was designed, and the key design points of key components were briefly described. During the industrial test, 3 710 large-diameter drill pipes were unloaded by the large-diameter drill pipe unloading device, with stable action and reliable performance, which met the application requirements of loading and unloading large-diameter drill pipes by tunnel drilling rig.

Workpiece placing and removing for punching press operated by hand have low precision, low efficiency and poor security. The workpiece automatic placing and removing of punching press driven by pneunmtic is introduced in this paper. The overall structure and operating principle of manipulator are given. The pneumatic control and PLC program control are advanced to realize stepless speed regulation, overload protection and to complete complex actions easily. The substitute clamping jaw of manipulator is researched. The design shows the advantages such as simple structure, low cost, easy to operate and maintenance, high efficiency and reliability. [ABSTRACT FROM AUTHOR]

This paper presented a method for the multi-agent based embedded system control of manipulator based on the integration of multi-agent based distributed manipulator control with advanced embedded system technology. An ARM7 microcontroller and embedded real-time operating system µC/OS- II were employed to implement the multi-agent based control of the manipulator model HN-8. The whole implementation scheme was presented. [ABSTRACT FROM AUTHOR]