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Aiming at the problems of many types of goods and high labor consumption in the current logistics field, in order to meet the needs of rapid sorting of production lines, a 2-CPR/ RPU parallel mechanism with full-cycle freedom was proposed to improve the sorting efficiency of logistics goods and reduce the labor time cost. The three-dimensional model of 2-CPR/ RPU mechanism was drawn, and the degree of freedom of 2-CPR/ RPU mechanism was solved by screw theory. According to the modified Grübler-Kutzbach formula, the position inverse solution of the branch chain of the mechanism was analyzed by closed vector. Based on the inverse solution expression, the velocity Jacobian matrix of the mechanism was obtained. The algebraic method was used to analyze whether the singular configuration exists. The MATLAB language was programmed to solve the points that meet the working range and draw the working space. Finally, the finite element simulation analysis of the bearing weight of the mechanism was carried out. The results show that the 2-CPR/ RPU parallel mechanism has a total of three degrees of freedom, which can realize 2T1R type motion (translation along the x, z axis and rotation around the x axis). The structure size meets the requirements without singular configuration, the working space is large, evenly distributed and fan-shaped symmetry, and the rotation of the execution platform can reach 60°. The 2-CPR/ RPU parallel mechanism has simple structure, stable motion, high working accuracy and good load performance, which is suitable for sorting and packing in most logistics packaging production lines [ABSTRACT FROM AUTHOR]

Context: In the era of minimally invasive surgeries, pediatric laparoscopic surgeries are now becoming the standard of care. Aim: In this study, we aim to determine the safe and optimal pneumoperitoneal pressures (PPs) for laparoscopic surgery in children aged 1-5 years, along with the technical ease for the surgeon. Settings and Design: Prospective, randomized, single blinded study was conducted at SGPGI Lucknow. Materials and Methods: Children aged 1-5 years were randomized into Group I (n = 24): PP = 6-8 mmHg and Group II: (PP) = 9-10 mmHg. Hemodynamic, ventilatory, and blood gas changes were measured before CO2 insufflation (T0), 20 min after insufflation (T1), before desufflation (T2), and 10 min after desufflation (T3). Surgeon's technical ease of surgery, postoperative pain, the requirement of rescue analgesia, time to resume feeding, and complications were recorded and analyzed. Statistical Analysis Used: Paired t test, Mann--Whitney test, and Wilcoxon signed rank test were used for nonparametric/parametric data. Chi-square/Fisher's test was used for nominal data. Results: Partial pressure of CO2 (PaCO2) was significantly higher in Group II at T1, T2, and T3, requiring frequent changes in ventilatory settings. Postoperative pain scores were higher in Group II at 1, 6, and 12 h, requiring rescue analgesia. Surgeon's scores and hemodynamics were similar in both groups. Conclusions: Higher PP in Group II caused significant changes in PaCO2, end tidal CO2, and postoperative pain requiring rescue analgesia, but blood gas changes were clinically insignificant and there were no significant changes in hemodynamic parameters. Since the surgeon's ease of performing surgery was similar in both groups, we recommend that laparoscopy in children aged 1-5 years can be started with lower PPs of 6-8 mmHg, which can be increased if needed based on the surgeon's comfort and the patient's body habitus. [ABSTRACT FROM AUTHOR]

In order to cope with the current express industry which requires a large number of staff to stack and sort express pieces every day, the 2-PCR_2-UPS asymmetric parallel mechanism was used to investigate whether it could be applied to the stacking and sorting of products in the express industry as well as in other industries. The 2-PCR_2-UPS parallel mechanism was modeled by Solid- Works software. The degrees of freedom of the 2-PCR_2-UPS mechanism was analyzed based on the screw theory and combined the modified version of the G-K(Grübler-Kutzbach) formula to verify the correctness of the 2-PCR_2-UPS mechanism. The closed-loop vector method was mainly used to solve the inverse kinematics of the mechanism, the MATLAB program language was used to draw the mechanism workspace. The virtual prototype was established in Adams software for simulation analysis. The results show that the 2-PCR_2-UPS mechanism has four degrees of freedom, including three movements (movement along the X, Y and Z axes) and one rotation (rotation around the Z axis), and presents a symmetrical distribution and a large range of workspace, and has good motion performance. 2-PCR_2-UPS mechanism has a simple and fast structure and large working space, which can replace manual stacking and sorting and significantly improve work efficiency. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic 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 bad environment of coke oven top and low accuracy of manual temperature measurement， a scorpion like robot for coke oven temperature measurement is designed. The robot is composed of walking mechanism and actuator. The overall structure of the temperature measuring robot is modeled， the kinematics equation of the manipulator is solved and simulated and its motion trajectory is planned. The workspace of the furnace cover lifting mechanism is analyzed to obtain the reachable space range of the end manipulator. The robot physical prototype is made to verify the positioning of the robot temperature measuring manipulator， and the error is within 2 mm. The workspace verification of the cover lifting mechanism can realize the workspace obtained by Monte Carlo， which lays a foundation for actual temperature measurement.

Aims: This study aimed to test the efficacy of SGPGI protocol to minimise bowel distension and optimise working space for laparoscopic pyeloplasty in infants. Methodology: All infants who underwent laparoscopic pyeloplasty for unilateral pelvi-ureteric junction obstruction (PUJO) between January 2017 and March 2020 were included in the study. The patient cohort was divided into two groups: Group A and B. Group A included patients who underwent routine pre-operative preparation. Group B included patients wherein the SGPGI protocol was used. The key features of the protocol were fasting for 8 h, enemas, inserting a nasogastric tube in the pre-operative period and decompressing the colon on the operation table. Demographic features, pre-operative, intraoperative and post-operative parameters were compared between the two groups. Results: A total of 26 infants with unilateral PUJO underwent laparoscopic pyeloplasty during the study period. Group A included 12 patients and Group B included 14 patients. Both the groups were similar in age, weight and sex distribution. The median surgeon's rating score for suturing conditions was 2 for Group A and 5 for Group B patients (P > 0.05). The operating time was significantly longer in Group A (196 ± 21 min) as compared to Group B (114 ± 18 min) (P < 0.05). In Group A, intra-abdominal pressure (IAP) varied between 9 and 14 mmHg (median 12 mmHg), while in Group B, IAP varied between 6 and 9 mmHg (median 8 mmHg) (P < 0.05). In Group A, in 2/12 cases (16.7%), conversion to an open procedure was necessary because of inadequate working space owing to gross intestinal distension. Two patients in Group A also had intraoperative injuries to adjacent structures due to poor working space. Conclusions: Optimal working space is critical to the performance of advanced laparoscopic surgery like pyeloplasty in infants. SGPGI protocol significantly improves working space, which permits a faster and safer surgery with a lower intra-abdominal working pressure. This protocol is simple, safe and easy to replicate at most centres in our country.

Transmission line is an important channel for power transmission, multi-split transmission line is the main force of power transmission, and splicing tube is an important hardware on multi-split transmission line. The quality of its crimping and internal structure are hidden projects and directly affect the normal and stable operation of the power transmission line. Based on this, a robot mechanism configuration suitable for the flaw detection of multi-split transmission line connection pipes was proposed, a virtual prototype model of the flaw detection detection robot was designed, and the flaw detection motion operation planning of the flaw detection device was launched, the D-H coordinate system of the flaw detection device was established, based on this, the kinematic equation of the flaw detection robot was deduced and its kinematic characteristics was analyzed. Finally, based on the established kinematic model and the Monte Carlo method in MATLAB software, the ROBOT TOOLBOX was used in the simulation experiment, so that the reachable space point cloud figure of the flaw detection robot end in three spatial directions in the narrow space of the four-split wire was obtained by selecting the appropriate number of point clouds. At the same time, the robot arm mode was built, through setting reasonable motion parameters, the trajectory planning simulation results of the robot flaw detection and detection were obtained. The simulation results show that the robot end can achieve flaw detection without blind spots in the narrow working space formed by the four-split lines. At the same time, the movement trajectory of the robot arm is stable and smooth, and the detection and detection of splicing pipes on multi-split conductors without collision and obstacle avoidance can be realized. The result has important theoretical significance and practical application for the system design and development of the splicing pipe flaw detection device for transmission lines and the intelligent operation and maintenance management of transmission grids. [ABSTRACT FROM AUTHOR]

Owing to the complex structures of welding materials, special welding conditions, and challenges during the automatic welding of the liquefied natural gas (LNG) ship Mark III's membrane tank, a series–parallel–series hybrid structure mobile welding robot having sufficient adaptability for welding corrugated plates in membrane tanks was designed in this study. The configuration of the hybrid robot had good workspace characteristics, and it could always maintain a certain distance and angle between the end of the welding torch and the weld line because of its detection and control system coordination. In this study, degrees of freedom, kinematic characteristics, workspace, and adaptability analyses were conducted for the hybrid mechanism. A simulation verification was performed, and a ripple-trajectory-following experiment was conducted using real objects. The simulation and experimental results showed that the welding robot had a reasonable mechanism design, smooth motion, and good terminal distance and angle control, thus meeting the requirements for automatic welding of corrugated plates in membrane tanks. [ABSTRACT FROM AUTHOR]

Study design: Prospective study. Objective: The aim of this study is to visualize the morphology of a lumbar herniated disc and Kambin's triangle in three dimensions (3D) based on preoperative CT/MRI fusion images. Methods: CT/MRI fusion images of 23 patients (10 males and 13 females; mean age 58.2 years) were used to evaluate Kambin's triangle, which is created between the superior articular process (SAP), exiting nerve root (ENR), inferiorly by the superior endplate of the lower lumbar vertebra and dural canal medially at 60 degree and 45 degree endoscopic approach angles. The percentage of the safe usage of transforaminal endoscopic approach was evaluated to utilize a 5 mm dilater without partial facet resection in the fusion image. The 3D lumbar nerve root sleeve angulation (3DNRA), which is the angle between the axis of the thecal sac and the nerve root sleeve, was calculated. The herniated discs were also visualized in the CT/MRI fusion image. Results: The 3DNRA became smaller from L2 to S1. The L2 3DNRA was statistically larger than those of the other root, and the S1 3DNRA was significantly smaller than the others (p < 0.05). (L2, 41.0°; L3, 35.6°; L4, 36.4°; L5, 33.9°; and S1, 23.2°). The SAP-ENR distance at 60° was greatest at L4/5 (5.9 mm). Possible needle passages at 60° to each disc level were 89.1% at L2/3, 87.0% at L3/4 and 84.8% at L4/5. However, the safe 5 mm dilater passage at 60° without bony resection to each disc level were 8.7% at L2/3, 28.3% at L3/4 and 37.0% at L4/5. The 60° corridor at L2/3 was the narrowest (p < 0.01). All herniated discs were visualized in the fusion image and the root compression site was clearly demonstrated especially with foraminal/extraforaminal herniations. Conclusion: The 3D lumbar CT/MRI fusion image enabled a combined nerve-bony assessment of Kambin's triangle and herniated disc. A fully endoscopic 5 mm dilater may retract the exiting nerve root in more than 60% of total cases. This new imaging technique could prove to be very useful for the safety of endoscopic lumbar disc surgery. [ABSTRACT FROM AUTHOR]

Aims: This study aimed to test the efficacy of SGPGI protocol to minimise bowel distension and optimise working space for laparoscopic pyeloplasty in infants. Methodology: All infants who underwent laparoscopic pyeloplasty for unilateral pelvi-ureteric junction obstruction (PUJO) between January 2017 and March 2020 were included in the study. The patient cohort was divided into two groups: Group A and B. Group A included patients who underwent routine pre-operative preparation. Group B included patients wherein the SGPGI protocol was used. The key features of the protocol were fasting for 8 h, enemas, inserting a nasogastric tube in the pre-operative period and decompressing the colon on the operation table. Demographic features, pre-operative, intraoperative and post-operative parameters were compared between the two groups. Results: A total of 26 infants with unilateral PUJO underwent laparoscopic pyeloplasty during the study period. Group A included 12 patients and Group B included 14 patients. Both the groups were similar in age, weight and sex distribution. The median surgeon's rating score for suturing conditions was 2 for Group A and 5 for Group B patients (P > 0.05). The operating time was significantly longer in Group A (196 ± 21 min) as compared to Group B (114 ± 18 min) (P < 0.05). In Group A, intra-abdominal pressure (IAP) varied between 9 and 14 mmHg (median 12 mmHg), while in Group B, IAP varied between 6 and 9 mmHg (median 8 mmHg) (P < 0.05). In Group A, in 2/12 cases (16.7%), conversion to an open procedure was necessary because of inadequate working space owing to gross intestinal distension. Two patients in Group A also had intraoperative injuries to adjacent structures due to poor working space. Conclusions: Optimal working space is critical to the performance of advanced laparoscopic surgery like pyeloplasty in infants. SGPGI protocol significantly improves working space, which permits a faster and safer surgery with a lower intra-abdominal working pressure. This protocol is simple, safe and easy to replicate at most centres in our country. [ABSTRACT FROM AUTHOR]

[Objectives] The manual lifting mode is often used for the shafting installation at present,for which a lot of manpower and man hours are required to complete the installation and it is not easy to repair and adjust. In order to improve the automation level of the shafting installation, a special six-degree-of-freedom parallel motion platform is designed to realize the intelligent installation of the shafting.[Methods] A sensor-based observation model was established to use the trilateral centroid localization algorithm to locate the shaft segment. The positional conditions of the contact point between the motion platform and the shaft segment were calculated,and the limit position conditions of various working conditions of the motion platform were analyzed to obtain the working space of the shaft segment.[Results] In view of the above,the safety of the working space for installation of the shaft segment can be estimated,and unnecessary damage during assembly work can be effectively avoided,[Conclusions] the study can provide theoretical guidance and technical support for engineering applications.

SUMMARY: In this paper, a new type of biped mobile robot is designed. Each leg of the robot is a 6 degree-of-freedom (DOF) parallel mechanism, and each leg has three relatively fixed landing points. The leg's structure gives the robot better performance on large carrying capacity, strong environmental adaptability and fast moving speed simultaneously. At the same time, it helps the robot move more steadily and change direction more simply. Based on the structural features of the leg, the inverse kinematics model of the biped robot is established and a unified formula is obtained. According to an analysis of robot's workspace, gait planning is completed and simulated. Finally, the special case that the robot can keep the upper body horizontal while walking on a slopy surface is validated. [ABSTRACT FROM AUTHOR]

The tomato picking lifting platform is the carrier for the installation of the picking manipulator, which directly affects the operating range, speed, and picking effect of the picking manipulator. Based on the six degree of freedom motion platform, this paper designs a tomato lifting platform with automatic lifting and automatic leveling functions, which can accurately dock at the designated height to complete the picking operation, and verifies the validity of its parameters and the rationality of the operation movement. First, we analyzed the tomato planting mode and growth characteristics of greenhouse; determined the predetermined trajectory, mechanism travel, and motion form of the lifting platform to complete the lifting process during tomato picking; and determined the basic design parameters of the platform; Secondly, we used SolidWorks to build the three-dimensional model of the lifting platform, and imported it into ADAMS. We used the driving function to complete the dynamic simulation of the virtual prototype of the lifting platform, and obtained the force curve of the electric cylinder and hinge. We analyzed the force on the electric cylinder and hinge of the lifting platform to determine the rationality of the device design. Finally, according to the design requirements and simulation data, we made the prototype of the lifting platform, constructed the motion control system, and carried out relevant experiments. The experimental results show that the maximum rotation angle around the x, y, and z axis is ±10°, the maximum lifting distance is 15 cm, and the maximum load is 50 kg; meanwhile, the average time for the system to reach steady state is 0.309 s, the in-tilt error increases with the increase in biaxial tilt angle, with the maximum error of 1.09°, and the maximum mean square root error of 0.119°, which can meet the automatic operation requirements of the tomato picking manipulator.

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical 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.)

A comprehensive analysis of the quality parameters of fused cast aluminum-zirconium-silicate (AZS) refractories for glass furnaces has been carried out. It was shown that the assessment of the quality of AZS refractories based on the content of ZrO2 and density does not fairly reflect their performance characteristics. Of fundamental importance are the chemical composition and behavior of the glassy phase, which determine the volume and exudation onset temperature. The most important conditions for obtaining high-quality AZS refractories, characterized by a glassy phase melt-out volume of 2 – 3% and melt-out onset temperature above 1,400°C, include the use of an oxidative melting technology and the content of impurities in the chemical composition of the refractory of no more than 0.25 – 0.30%. The service conditions of AZS refractories in the melting tank and the working space of glass-melting furnaces have been formulated. Their effect on the exudation process behavior, corrosion resistance of the refractories, and formation of glass defects was shown. [ABSTRACT FROM AUTHOR]

Background: For metabolic laparoscopic surgery, higher pressures up to 20 mmHg are often used to create a surgical field of sufficient quality. This randomized pilot study aimed to determine the feasibility, safety and tolerability of low intraabdominal pressure (IAP) and deep neuromuscular blockade (NMB) to reduce postoperative pain.Methods: In a teaching hospital in the Netherlands, 62 patients eligible for a laparoscopic Roux-en-Y gastric bypass (LRYGB) were randomized into one of four groups in a 2 × 2 factorial design: deep/moderate NMB and standard (20 mmHg)/low IAP (12 mmHg). Patient and surgical team were blinded. Primary outcome measure was the surgical field quality, scored on the Leiden-Surgical Rating Scale (L-SRS). Secondary outcome measures were (serious) adverse events, duration of surgery and postoperative pain.Results: 62 patients were included. L-SRS was good or perfect in all patients that were operated under standard IAP with deep or moderate NMB. In 40% of patients with low IAP and deep NMB, an increase in IAP was needed to improve surgical overview. In patients with low IAP and moderate NMB, IAP was increased to improve surgical overview in 40%, and in 75% of these cases a deep NMB was requested to further improve the surgical overview. Median duration of surgery was 38 min (IQR34-40 min) in the group with standard IAP and moderate NMB and 52 min (IQR46-55 min) in the group with low IAP and deep NMB.Conclusions: The combination of moderate NMB and low IAP can create insufficient surgical overview. Larger trials are needed to corroborate the findings of this study.Trial Registration: Dutch Trial Register: Trial NL7050, registered 28 May 2018. https://www.trialregister.nl/trial/7050 . [ABSTRACT FROM AUTHOR]

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical 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.)

Study design: Prospective study. Objective: The aim of this study is to visualize the morphology of a lumbar herniated disc and Kambin’s triangle in three dimensions (3D) based on preoperative CT/MRI fusion images. Methods: CT/MRI fusion images of 23 patients (10 males and 13 females; mean age 58.2 years) were used to evaluate Kambin’s triangle, which is created between the superior articular process (SAP), exiting nerve root (ENR), inferiorly by the superior endplate of the lower lumbar vertebra and dural canal medially at 60 degree and 45 degree endoscopic approach angles. The percentage of the safe usage of transforaminal endoscopic approach was evaluated to utilize a 5 mm dilater without partial facet resection in the fusion image. The 3D lumbar nerve root sleeve angulation (3DNRA), which is the angle between the axis of the thecal sac and the nerve root sleeve, was calculated. The herniated discs were also visualized in the CT/MRI fusion image. Results: The 3DNRA became smaller from L2 to S1. The L2 3DNRA was statistically larger than those of the other root, and the S1 3DNRA was significantly smaller than the others (p < 0.05). (L2, 41.0°; L3, 35.6°; L4, 36.4°; L5, 33.9°; and S1, 23.2°). The SAP-ENR distance at 60° was greatest at L4/5 (5.9 mm). Possible needle passages at 60° to each disc level were 89.1% at L2/3, 87.0% at L3/4 and 84.8% at L4/5. However, the safe 5 mm dilater passage at 60° without bony resection to each disc level were 8.7% at L2/3, 28.3% at L3/4 and 37.0% at L4/5. The 60° corridor at L2/3 was the narrowest (p < 0.01). All herniated discs were visualized in the fusion image and the root compression site was clearly demonstrated especially with foraminal/extraforaminal herniations. Conclusion: The 3D lumbar CT/MRI fusion image enabled a combined nerve-bony assessment of Kambin’s triangle and herniated disc. A fully endoscopic 5 mm dilater may retract the exiting nerve root in more than 60% of total cases. This new imaging technique could prove to be very useful for the safety of endoscopic lumbar disc surgery.

Copyright of Journal of South China University of Technology (Natural Science Edition) is the property of South China 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.)

Today, many highly qualified women, with specializations in traditional or innovative areas, are found working as consultants, assistants or selfemployed professionals: their fragmented career paths include going back and forth between different places where and from which they work. In this context, the home is one of the working spaces, where new opportunities and old contradictions can be found. The desire for autonomy and the satisfaction of using one's own skills to create ideas and projects that find their place in the labor market coexist with the need for unlimited investment on many fronts in terms of time and personal commitment that does not preclude the feeling of isolation and solitude. Teleworking and the intensive use of technological means create the feeling of "working without a body". The article sheds light on "emptiness and fullness" with regard to corporality and highlights the "dematerialization effects" that occur within the organization of "remote" work, especially when it is carried out in the domestic space. In terms of methodology, the use of a biographical and narrative approach made it possible to understand the experiences of the women interviewed based on the meaning they themselves give to their own work experiences and their unique position in the domestic space. [ABSTRACT FROM AUTHOR]

Aim to the problems of low load and precision of the serial manipulator used in casting operation. Casting execution equipment based on 2UPR-2RPU mechanism was designed. A prototype of heavy-duty casting robot has been proposed and developed. Based on the theory of robot topology, the mechanism constraint relation of the casting execution equipment was analyzed, and it is concluded that the casting actuator has three degrees of freedom. Both the inverse position equation of the casting execution equipment and axial velocity equation of branch chain were established. In this article, kinematics simulation of the casting execution equipment based on ADAMS software was presented, and its kinematics characteristics of each parallel branch chain were analyzed. The validity of this kinematics model of casting actuator was verified. Based on the working space analysis method for parallel mechanism, the working space range of casting execution equipment was simulated by the MATLAB software. This research provides a reference for expanding the application of hybrid structural robot in casting field and developing casting heavy-duty casting robotic products. [ABSTRACT FROM AUTHOR]

A new type of 3-PPR spherical parallel mechanism is proposed.Due to the mobile pair special trajectory in each branch chain,the mobile pair can be equivalent conversion for revolute pair.Based on screw theory,each branched chain motion screw system is given.The mobility of this mechanism is analyzed firstly with the amendment G-K formula,The numbers of degrees of freedom is obtained.Secondly,by using the solution method of inverse spiral system and matrix theory knowledge,under the premise of Jacobian matrix of the 3-PPR spherical parallel mechanism is solved,the rank of matrix is analyzed,the singular configuration conditions and the type of singular configuration of the mechanism are obtained.In the end,according to the forward kinematics solution and interference condition,the Matlab software is used to draw up the stable working space.Research shows that a 3-PPR parallel spherical mechanism singularity is less,and easy to avoid,has good application prospect.

Aim to the problems of low load and precision of the serial manipulator used in casting operation. Casting execution equipment based on 2UPR-2RPU mechanism was designed. A prototype of heavy-duty casting robot has been proposed and developed. Based on the theory of robot topology, the mechanism constraint relation of the casting execution equipment was analyzed, and it is concluded that the casting actuator has three degrees of freedom. Both the inverse position equation of the casting execution equipment and axial velocity equation of branch chain were established. In this article, kinematics simulation of the casting execution equipment based on ADAMS software was presented, and its kinematics characteristics of each parallel branch chain were analyzed. The validity of this kinematics model of casting actuator was verified. Based on the working space analysis method for parallel mechanism, the working space range of casting execution equipment was simulated by the MATLAB software. This research provides a reference for expanding the application of hybrid structural robot in casting field and developing casting heavy-duty casting robotic products. [ABSTRACT FROM AUTHOR]

A method of determining the position of the surface modules within the working space of a machine tool is outlined. The method includes the formulation of rectangular coordinate systems for the machine tool and the surface modules and establishing their relative position. [ABSTRACT FROM AUTHOR]

A humanoid shoulder joint based on spherical 5R parallel mechanism is proposed according to the structural characteristics of human shoulder joint. The inverse position solution of parallel mechanism is derived through the idea of the Paden-Kahan sub-problem. A kinematics analysis method of the asymmetric parallel mechanism with few degrees of freedom is given based on the screw theory and the product of exponentials formula in combination with the direct method and the imaginary mechanism method, and the velocity jacobian matrix of parallel mechanism is obtained. The iterative sampling optimization method for multi-parameter is used to analyze the relationship between the evaluation index of working space and the structural parameter of the mechanism. A reasonable set of structural parameters is selected in consi- dering the processing assembly process. The research results show that the humanoid shoulder joint is compact, and has a large working space and conforms to the kinematical characteristics of human shoulder joint. [ABSTRACT FROM AUTHOR]

Focusing on the current limited vertical adjustment technique of large-scale drillings,a 6-DOF parallel adjustment equipment with 12 inputs is designed for the working condition of vertical drilling.The equipment mechanism consists of 6branched chains with redundancy which are symmetrical in structure.Each of the chains is composed by a compound of rotate joint and a compound of spherical joint,while the two pairs are connected by two prismatic pairs.The modal analysis is carried out on the body which is based on ANSYS software,first six order frequency distribution and modal vibration mode,and along the X、Y、Zdirection of the displacement frequency response about the moving platform are got.The analysis consequence shows that the most sensitive of external forces to the moving platform is 46 Hz frequency.Otherwise,the working space of the 6-DOF platform is obtained by using the 3-D searching algorithm.The results have significant meanings in the further research on the correlation between the parameters and the whole mechanism,as well as the optimization of the parameter.

Aiming at the defects such as blind detection and poor coupling effect of automatic detection of contact surface existing in the traditional ultrasonic detection technology used for detecting the defects of CRH wheel, a new parallel passive self coupling multi wafer probe mechanism is proposed, which can not only effectively eliminate the blind detection zone, but also ensure a good real-time coupling between ultrasonic probe and the wheel surface. A basic structure of the probe mechanism is introduced in this paper, and the degree of freedom of the mechanism is solved by using the topological structure theory based on the orientation feature set. An analysis is made on the mechanism for the automatic detection of the kinematic performance, and by using relevant software, the mechanism parameters are simulated, and the working space of the mechanism is obtained, which lays a theoretical foundation for the full implementation of the automatic ultrasonic detection of the train wheel defects. [ABSTRACT FROM AUTHOR]

The study of robot workspace is an interesting problem since its applications are directly related to industry. However, it involves several mathematical complications; Thus, many of the arising questions are left without a definite answer. With the motivation of industrial demand, the need for finding better answers than the existing ones lasts. The workspace (WS) determination of a robot with general structural parameters is a complex problem, which cannot be solved in an explicit way. Closed form solutions are only available in some particular cases. Otherwise, computational algorithms and numerical techniques are used. The task becomes even much more complicated by the presence of obstacles in the robot accessible region. Obstacle presence does not only exclude points from the original WS but it affects the whole robot workspace’s shape and size to the extent that it sometimes divides the working space in two or more separate regions that cannot be linked by the same robot. Much research work in the literature is directed toward path planning in the presence of obstacles without having to determine the robot WS. However, a real situation in industry occurs when the knowledge of the WS is of importance in facility layout. This paper presents an approach for the estimation of a generic open-chain robot in the presence of obstacles with any desired number of prismatic and/or revolute joints of any order. Joints’ axes may have any orientation relative to each other. The robot can be placed in free space or in a work cell consisting of a set of Computer Numerically Controlled (CNC) machines and some obstacles.

The construction and form of the transfer object depend on process parameters and influence the technological parameters and the state parameters of the process. The most frequently used form of transfer object is the disk form. In accordance with the type of operation we may use electrodes under the form of band and sometimes, very seldom, under the form of wire. The paper presents a transfer object under the form of stratified disk that allows the introduction of the working fluid through it..