Purpose This paper aims to investigate the additive manufacturing (AM) approach of a spatial complex curve feature (SCCF, mapped from two-dimensional nonuniform rational B-splines [2D-NURBS] curve) on a complex surface based on a serial robot using plasma built-up welding, and lays a foundation for plasma AM SCCFs on complex surfaces by combining the NURBS theory with the serial robotic kinematics. Design/methodology/approach Combining serial robotic kinematics and NURBS theory, a SCCF mapped from a square-like 2D-NURBS curve is prepared on a predefined complex NURBS surface using serial robotic plasma AM. The interpolation points C (ui) on the square-like 2D-NURBS curve are obtained using the equi-chord length interpolation method, and mapped on a predefined NURBS surface to get mapped points S (ui, vj). The homogeneous transformation matrix T = [n o a S (ui, vj)] of the plasma torch is calculated using the mapped points S (ui, vj) and the designated posture [n o a]. Using the inverse kinematics of the serial robot, the joint vector θ of the serial robot can be computed. After that, the AM programs are generated and transferred into the serial robotic controller and carried out by the serial robot of Motoman-UP6. The 2D-NURBS curve (square-like) is considered as AM trajectory planning curve, while its corresponding SCCF mapped from the 2D-NURBS curve as AM trajectory. Findings Simulation and experiments show that the preparation of SCCF (mapped from 2D-NURBS curve) on complex NURBS surface using robotic plasma AM is feasible and effective. Originality/value A SCCF mapped from a 2D-NURBS curve is prepared on a complex NURBS surface using the serial robotic plasma AM for the first time. It provides a theoretical and technical basis for plasma AM to produce SCCFs on complex surfaces. With the increasing demand for surface remanufacturing of complex parts, the serial robotic plasma AM of SCCFs on complex NURBS surfaces has a broad application prospect in aero-engine components, high-speed rail power components, nuclear industry components and complex molds.
目的研究基于等离子体堆焊串联机器人的复杂曲面空间复杂曲线特征(SCCF,从二维非均匀有理b样条曲线[2D-NURBS]曲线映射)的增材制造方法,并将NURBS理论与串联机器人运动学相结合,为复杂曲面等离子体增材制造SCCF奠定基础。设计/方法/方法结合连续机器人运动学和NURBS理论,利用连续机器人等离子体增材制造技术在预定义的复杂NURBS曲面上制备了由方形2D-NURBS曲线映射的SCCF。采用等弦长插值方法在类方形2D-NURBS曲线上获得插值点C (ui),并将其映射到预定义的NURBS曲面上,得到映射点S (ui, vj)。利用映射点S (ui, vj)和指定姿态[n o a]计算等离子炬的齐次变换矩阵T = [n o a S (ui, vj)]。利用串联机器人的运动学逆解,可以计算出串联机器人的关节向量θ。然后生成调幅程序,并将其传输到串行机器人控制器中,由Motoman-UP6串行机器人执行。将2D-NURBS曲线(方形)视为AM轨迹规划曲线,其对应的SCCF从2D-NURBS曲线映射为AM轨迹。仿真和实验结果表明,利用机器人等离子体增材制造复杂NURBS曲面上的SCCF (2D-NURBS曲线映射)是可行和有效的。首次使用串行机器人等离子体AM在复杂的NURBS表面上制备了从2D-NURBS曲线映射的SCCF。为等离子体增材制造复杂表面上的sccf提供了理论和技术基础。随着复杂零件表面再制造需求的不断增加,在复杂NURBS表面上连续机器人等离子体增材制造sccf在航空发动机部件、高铁动力部件、核工业部件和复杂模具等领域具有广阔的应用前景。
{"title":"Serial robotic plasma additive manufacturing on complex NURBS surface","authors":"Zhaoqin Wang, Yu Shi, Xiaorong Wang","doi":"10.1108/ir-04-2022-0097","DOIUrl":"https://doi.org/10.1108/ir-04-2022-0097","url":null,"abstract":"\u0000Purpose\u0000This paper aims to investigate the additive manufacturing (AM) approach of a spatial complex curve feature (SCCF, mapped from two-dimensional nonuniform rational B-splines [2D-NURBS] curve) on a complex surface based on a serial robot using plasma built-up welding, and lays a foundation for plasma AM SCCFs on complex surfaces by combining the NURBS theory with the serial robotic kinematics.\u0000\u0000\u0000Design/methodology/approach\u0000Combining serial robotic kinematics and NURBS theory, a SCCF mapped from a square-like 2D-NURBS curve is prepared on a predefined complex NURBS surface using serial robotic plasma AM. The interpolation points C (ui) on the square-like 2D-NURBS curve are obtained using the equi-chord length interpolation method, and mapped on a predefined NURBS surface to get mapped points S (ui, vj). The homogeneous transformation matrix T = [n o a S (ui, vj)] of the plasma torch is calculated using the mapped points S (ui, vj) and the designated posture [n o a]. Using the inverse kinematics of the serial robot, the joint vector θ of the serial robot can be computed. After that, the AM programs are generated and transferred into the serial robotic controller and carried out by the serial robot of Motoman-UP6. The 2D-NURBS curve (square-like) is considered as AM trajectory planning curve, while its corresponding SCCF mapped from the 2D-NURBS curve as AM trajectory.\u0000\u0000\u0000Findings\u0000Simulation and experiments show that the preparation of SCCF (mapped from 2D-NURBS curve) on complex NURBS surface using robotic plasma AM is feasible and effective.\u0000\u0000\u0000Originality/value\u0000A SCCF mapped from a 2D-NURBS curve is prepared on a complex NURBS surface using the serial robotic plasma AM for the first time. It provides a theoretical and technical basis for plasma AM to produce SCCFs on complex surfaces. With the increasing demand for surface remanufacturing of complex parts, the serial robotic plasma AM of SCCFs on complex NURBS surfaces has a broad application prospect in aero-engine components, high-speed rail power components, nuclear industry components and complex molds.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"33 1","pages":"246-255"},"PeriodicalIF":1.8,"publicationDate":"2022-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90592046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Purpose The purpose of this paper is to present a novel laser pointer for manual coating robot teaching. The laser pointer has simple structure and no physical contact with substrate in teaching work. The sensitivity of visual detection in the design accuracy is guaranteed. Design/methodology/approach The strategy adopts two laser sources to form a triangle to achieve a fixed distance detection pointer for manual robot teaching. After optimizing the source, spot size and the incident angle of the lasers, the sensitivity of fixed-distance judgment is analyzed and compared with traditional pointers. In addition, the laser pointer adds the functions to simulate coating atomizer, including posture and overlap pitch. Finally, the laser pointer verified by coating application and measurement system analysis evaluation. Findings The laser pointer has been successfully applied to coating robot teaching by the authors’ team. From the simulation and experimental results, it can be concluded that the proposed approach is effective at improving manual teaching of coating robot, especially for the complex geometry. Research limitations/implications The main function of the laser pointer often used for manual teaching in other purposes; for example, sealer etc. The paper innovatively considered and tested the laser pointer on robotic coating process. Originality/value Compared with the traditional hard straight stick pointer, the paper proposes a very simple construction for teaching pointer with laser feature. At the same time, the requirement of coating process simulation is considered.
{"title":"Laser pointer for manual teaching of coating robot","authors":"Zhiyong Shang","doi":"10.1108/ir-04-2022-0091","DOIUrl":"https://doi.org/10.1108/ir-04-2022-0091","url":null,"abstract":"\u0000Purpose\u0000The purpose of this paper is to present a novel laser pointer for manual coating robot teaching. The laser pointer has simple structure and no physical contact with substrate in teaching work. The sensitivity of visual detection in the design accuracy is guaranteed.\u0000\u0000\u0000Design/methodology/approach\u0000The strategy adopts two laser sources to form a triangle to achieve a fixed distance detection pointer for manual robot teaching. After optimizing the source, spot size and the incident angle of the lasers, the sensitivity of fixed-distance judgment is analyzed and compared with traditional pointers. In addition, the laser pointer adds the functions to simulate coating atomizer, including posture and overlap pitch. Finally, the laser pointer verified by coating application and measurement system analysis evaluation.\u0000\u0000\u0000Findings\u0000The laser pointer has been successfully applied to coating robot teaching by the authors’ team. From the simulation and experimental results, it can be concluded that the proposed approach is effective at improving manual teaching of coating robot, especially for the complex geometry.\u0000\u0000\u0000Research limitations/implications\u0000The main function of the laser pointer often used for manual teaching in other purposes; for example, sealer etc. The paper innovatively considered and tested the laser pointer on robotic coating process.\u0000\u0000\u0000Originality/value\u0000Compared with the traditional hard straight stick pointer, the paper proposes a very simple construction for teaching pointer with laser feature. At the same time, the requirement of coating process simulation is considered.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"17 1","pages":"211-218"},"PeriodicalIF":1.8,"publicationDate":"2022-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90961230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Purpose Multi-sensor fusion in robotic dexterous hands is a hot research field. However, there is little research on multi-sensor fusion rules. This study aims to introduce a multi-sensor fusion algorithm using a motor force sensor, film pressure sensor, temperature sensor and angle sensor, which can form a consistent interpretation of grasp stability by sensor fusion without multi-dimensional force/torque sensors. Design/methodology/approach This algorithm is based on the three-finger force balance theorem, which provides a judgment method for the unknown force direction. Moreover, the Monte Carlo method calculates the grasping ability and judges the grasping stability under a certain confidence interval using probability and statistics. Based on three fingers, the situation of four- and five-fingered dexterous hand has been expanded. Moreover, an experimental platform was built using dexterous hands, and a grasping experiment was conducted to confirm the proposed algorithm. The grasping experiment uses three fingers and five fingers to grasp different objects, use the introduced method to judge the grasping stability and calculate the accuracy of the judgment according to the actual grasping situation. Findings The multi-sensor fusion algorithms are universal and can perform multi-sensor fusion for multi-finger rigid, flexible and rigid-soft coupled dexterous hands. The three-finger balance theorem and Monte Carlo method can better replace the discrimination method using multi-dimensional force/torque sensors. Originality/value A new multi-sensor fusion algorithm is proposed and verified. According to the experiments, the accuracy of grasping judgment is more than 85%, which proves that the method is feasible.
{"title":"Judgment method of grasping stability for dexterous hand based on force balance theorem and Monte Carlo method","authors":"Yinghan Wang, Diansheng Chen, Zhe Liu","doi":"10.1108/ir-05-2022-0125","DOIUrl":"https://doi.org/10.1108/ir-05-2022-0125","url":null,"abstract":"\u0000Purpose\u0000Multi-sensor fusion in robotic dexterous hands is a hot research field. However, there is little research on multi-sensor fusion rules. This study aims to introduce a multi-sensor fusion algorithm using a motor force sensor, film pressure sensor, temperature sensor and angle sensor, which can form a consistent interpretation of grasp stability by sensor fusion without multi-dimensional force/torque sensors.\u0000\u0000\u0000Design/methodology/approach\u0000This algorithm is based on the three-finger force balance theorem, which provides a judgment method for the unknown force direction. Moreover, the Monte Carlo method calculates the grasping ability and judges the grasping stability under a certain confidence interval using probability and statistics. Based on three fingers, the situation of four- and five-fingered dexterous hand has been expanded. Moreover, an experimental platform was built using dexterous hands, and a grasping experiment was conducted to confirm the proposed algorithm. The grasping experiment uses three fingers and five fingers to grasp different objects, use the introduced method to judge the grasping stability and calculate the accuracy of the judgment according to the actual grasping situation.\u0000\u0000\u0000Findings\u0000The multi-sensor fusion algorithms are universal and can perform multi-sensor fusion for multi-finger rigid, flexible and rigid-soft coupled dexterous hands. The three-finger balance theorem and Monte Carlo method can better replace the discrimination method using multi-dimensional force/torque sensors.\u0000\u0000\u0000Originality/value\u0000A new multi-sensor fusion algorithm is proposed and verified. According to the experiments, the accuracy of grasping judgment is more than 85%, which proves that the method is feasible.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"11 1","pages":"203-210"},"PeriodicalIF":1.8,"publicationDate":"2022-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86511618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Purpose This paper aims to present a new approach for robot programming by demonstration, which generates robot programs by tracking 6 dimensional (6D) pose of the demonstrator’s hand using a single red green blue (RGB) camera without requiring any additional sensors. Design/methodology/approach The proposed method learns robot grasps and trajectories directly from a single human demonstration by tracking the movements of both human hands and objects. To recover the 6D pose of an object from a single RGB image, a deep learning–based method is used to detect the keypoints of the object first and then solve a perspective-n-point problem. This method is first extended to estimate the 6D pose of the nonrigid hand by separating fingers into multiple rigid bones linked with hand joints. The accurate robot grasp can be generated according to the relative positions between hands and objects in the 2 dimensional space. Robot end-effector trajectories are generated from hand movements and then refined by objects’ start and end positions. Findings Experiments are conducted on a FANUC LR Mate 200iD robot to verify the proposed approach. The results show the feasibility of generating robot programs by observing human demonstration once using a single RGB camera. Originality/value The proposed approach provides an efficient and low-cost robot programming method with a single RGB camera. A new 6D hand pose estimation approach, which is used to generate robot grasps and trajectories, is developed.
本文旨在提出一种新的机器人演示编程方法,该方法通过使用单个红绿蓝(RGB)相机跟踪演示者手部的6维(6D)姿势来生成机器人程序,而无需任何额外的传感器。设计/方法/方法所提出的方法通过跟踪人手和物体的运动,直接从单个人类演示中学习机器人的抓取和轨迹。为了从单个RGB图像中恢复物体的6D姿态,首先使用基于深度学习的方法检测物体的关键点,然后解决透视n点问题。首先将该方法扩展到非刚性手的6D姿态估计,将手指分离成多个与手关节相连的刚性骨骼。根据手与物体在二维空间中的相对位置,可以生成精确的机器人抓握。机器人末端执行器轨迹由手部运动生成,然后根据物体的起始和结束位置进行细化。在FANUC LR Mate 200iD机器人上进行了实验以验证所提出的方法。结果表明,利用单个RGB相机,通过观察人类演示一次,生成机器人程序是可行的。该方法提供了一种高效、低成本的单RGB相机机器人编程方法。提出了一种新的6D手部姿态估计方法,用于生成机器人抓取和轨迹。
{"title":"Robot programming by demonstration with a monocular RGB camera","authors":"Kaimeng Wang, Te Tang","doi":"10.1108/ir-04-2022-0093","DOIUrl":"https://doi.org/10.1108/ir-04-2022-0093","url":null,"abstract":"\u0000Purpose\u0000This paper aims to present a new approach for robot programming by demonstration, which generates robot programs by tracking 6 dimensional (6D) pose of the demonstrator’s hand using a single red green blue (RGB) camera without requiring any additional sensors.\u0000\u0000\u0000Design/methodology/approach\u0000The proposed method learns robot grasps and trajectories directly from a single human demonstration by tracking the movements of both human hands and objects. To recover the 6D pose of an object from a single RGB image, a deep learning–based method is used to detect the keypoints of the object first and then solve a perspective-n-point problem. This method is first extended to estimate the 6D pose of the nonrigid hand by separating fingers into multiple rigid bones linked with hand joints. The accurate robot grasp can be generated according to the relative positions between hands and objects in the 2 dimensional space. Robot end-effector trajectories are generated from hand movements and then refined by objects’ start and end positions.\u0000\u0000\u0000Findings\u0000Experiments are conducted on a FANUC LR Mate 200iD robot to verify the proposed approach. The results show the feasibility of generating robot programs by observing human demonstration once using a single RGB camera.\u0000\u0000\u0000Originality/value\u0000The proposed approach provides an efficient and low-cost robot programming method with a single RGB camera. A new 6D hand pose estimation approach, which is used to generate robot grasps and trajectories, is developed.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"31 1","pages":"234-245"},"PeriodicalIF":1.8,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81605165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Purpose This paper aims to present an adaptive sliding mode control (ASMC) for tunnel boring machine cutterhead telescopic system with uncertainties to achieve a high-precision trajectory in complex strata. This method could be applied to solve the problems caused by linear and nonlinear model uncertainties. Design/methodology/approach First, an integral-type sliding surface is defined to reduce the static tracking error. Second, a projection type adaptation law is designed to approximate the linear and nonlinear redefined parameters of the electrohydraulic system. Third, a nonlinear robust term with a continuous approximation function is presented for handling load force uncertainty and reducing sliding mode chattering. Moreover, Lyapunov theory is applied to guarantee the stability of the closed-loop system. Finally, the effectiveness of the proposed controller is proved by comparative experiments on a scaled test rig. Findings The linear and nonlinear model uncertainties lead to large variations in the dynamics of the mechanism and the tracking error. To achieve precise position tracking, an adaptation law was integrated into the sliding mode control which compensated for model uncertainties. Besides, the inherent sliding mode chattering was reduced by a continuous approximation function, while load force uncertainty was solved by a nonlinear robust feedback. Therefore, a novel ASMC for tunnel boring machine cutterhead telescopic system with uncertainties can improve its tracking precision and reduce the sliding mode chattering. Originality/value To the best of the authors’ knowledge, the ASMC is proposed for the first time to control the tunnel boring machine cutterhead telescopic system with uncertainties. The presented control is effective not only in control accuracy but also in parameter uncertainty.
{"title":"Adaptive sliding mode control for tunnel boring machine cutterhead telescopic system with uncertainties","authors":"Hangjun Zhang, Jin-hui Fang, Jianhua Wei, Huan Yu, Qiang Zhang","doi":"10.1108/ir-04-2022-0096","DOIUrl":"https://doi.org/10.1108/ir-04-2022-0096","url":null,"abstract":"\u0000Purpose\u0000This paper aims to present an adaptive sliding mode control (ASMC) for tunnel boring machine cutterhead telescopic system with uncertainties to achieve a high-precision trajectory in complex strata. This method could be applied to solve the problems caused by linear and nonlinear model uncertainties.\u0000\u0000\u0000Design/methodology/approach\u0000First, an integral-type sliding surface is defined to reduce the static tracking error. Second, a projection type adaptation law is designed to approximate the linear and nonlinear redefined parameters of the electrohydraulic system. Third, a nonlinear robust term with a continuous approximation function is presented for handling load force uncertainty and reducing sliding mode chattering. Moreover, Lyapunov theory is applied to guarantee the stability of the closed-loop system. Finally, the effectiveness of the proposed controller is proved by comparative experiments on a scaled test rig.\u0000\u0000\u0000Findings\u0000The linear and nonlinear model uncertainties lead to large variations in the dynamics of the mechanism and the tracking error. To achieve precise position tracking, an adaptation law was integrated into the sliding mode control which compensated for model uncertainties. Besides, the inherent sliding mode chattering was reduced by a continuous approximation function, while load force uncertainty was solved by a nonlinear robust feedback. Therefore, a novel ASMC for tunnel boring machine cutterhead telescopic system with uncertainties can improve its tracking precision and reduce the sliding mode chattering.\u0000\u0000\u0000Originality/value\u0000To the best of the authors’ knowledge, the ASMC is proposed for the first time to control the tunnel boring machine cutterhead telescopic system with uncertainties. The presented control is effective not only in control accuracy but also in parameter uncertainty.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"12 1","pages":"162-173"},"PeriodicalIF":1.8,"publicationDate":"2022-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78101838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yilong Jiang, Ting Wang, Shiliang Shao, Lebing Wang
Purpose In large-scale environments and unstructured scenarios, the accuracy and robustness of traditional light detection and ranging (LiDAR) simultaneous localization and mapping (SLAM) algorithms are reduced, and the algorithms might even be completely ineffective. To overcome these problems, this study aims to propose a 3D LiDAR SLAM method for ground-based mobile robots, which uses a 3D LiDAR fusion inertial measurement unit (IMU) to establish an environment map and realize real-time localization. Design/methodology/approach First, we use a normal distributions transform (NDT) algorithm based on a local map with a corresponding motion prediction model for point cloud registration in the front-end. Next, point cloud features are tightly coupled with IMU angle constraints, ground constraints and gravity constraints for graph-based optimization in the back-end. Subsequently, the cumulative error is reduced by adding loop closure detection. Findings The algorithm is tested using a public data set containing indoor and outdoor scenarios. The results confirm that the proposed algorithm has high accuracy and robustness. Originality/value To improve the accuracy and robustness of SLAM, this method proposed in the paper introduced the NDT algorithm in the front-end and designed ground constraints and gravity constraints in the back-end. The proposed method has a satisfactory performance when applied to ground-based mobile robots in complex environments experiments.
{"title":"3D SLAM based on NDT matching and ground constraints for ground robots in complex environments","authors":"Yilong Jiang, Ting Wang, Shiliang Shao, Lebing Wang","doi":"10.1108/ir-05-2022-0128","DOIUrl":"https://doi.org/10.1108/ir-05-2022-0128","url":null,"abstract":"\u0000Purpose\u0000In large-scale environments and unstructured scenarios, the accuracy and robustness of traditional light detection and ranging (LiDAR) simultaneous localization and mapping (SLAM) algorithms are reduced, and the algorithms might even be completely ineffective. To overcome these problems, this study aims to propose a 3D LiDAR SLAM method for ground-based mobile robots, which uses a 3D LiDAR fusion inertial measurement unit (IMU) to establish an environment map and realize real-time localization.\u0000\u0000\u0000Design/methodology/approach\u0000First, we use a normal distributions transform (NDT) algorithm based on a local map with a corresponding motion prediction model for point cloud registration in the front-end. Next, point cloud features are tightly coupled with IMU angle constraints, ground constraints and gravity constraints for graph-based optimization in the back-end. Subsequently, the cumulative error is reduced by adding loop closure detection.\u0000\u0000\u0000Findings\u0000The algorithm is tested using a public data set containing indoor and outdoor scenarios. The results confirm that the proposed algorithm has high accuracy and robustness.\u0000\u0000\u0000Originality/value\u0000To improve the accuracy and robustness of SLAM, this method proposed in the paper introduced the NDT algorithm in the front-end and designed ground constraints and gravity constraints in the back-end. The proposed method has a satisfactory performance when applied to ground-based mobile robots in complex environments experiments.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"30 6 1","pages":"174-185"},"PeriodicalIF":1.8,"publicationDate":"2022-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81073576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Purpose Pipeline robots are often used in pipeline non-destructive testing. Given the need for long-range in-pipe inspections, this study aims to develop a wireless in-pipe inspection robot for image acquisition. Design/methodology/approach In this paper, an in-pipe robot with a new mechanical system is proposed. This system combines a three-arm load-bearing structure with spring sleeves and a half-umbrella diametric change structure, which can ensure the stability of the camera when acquiring images while maintaining the robot’s flexibility. In addition, data were transmitted wirelessly via a system that uses a 433 MHz ultra-high frequency and wireless local-area network–based image transmission system. Software and practical tests were conducted to verify the robot’s design. A preliminary examination of the robot’s cruising range was also conducted. Findings The feasibility of the robot was demonstrated using CATIA V5 and MSC ADAMS software. The simulation results showed that the centre of mass of the robot remained in a stable position and that it could function in a simulated pipeline network. In the practical test, the prototype functioned stably, correctly executed remote instructions and transmitted in near real-time its location, battery voltage and the captured images. Additionally, the tests demonstrated that the robot could successfully pass through the bends in a 200-mm-wide pipe at any angle between 0° and 90°. In actual wireless network conditions, the electrical system functioned for 44.7 consecutive minutes. Originality/value A wheeled wireless robot adopts a new mechanical system. For inspections of plastic pipelines, the robot can adapt to pipes with diameters of 150–210 mm and has the potential for practical applications.
{"title":"Design of wireless in-pipe inspection robot for image acquisition","authors":"Kunlun Wu, H. Sang, Yan Xing, Yao Lu","doi":"10.1108/ir-02-2022-0043","DOIUrl":"https://doi.org/10.1108/ir-02-2022-0043","url":null,"abstract":"\u0000Purpose\u0000Pipeline robots are often used in pipeline non-destructive testing. Given the need for long-range in-pipe inspections, this study aims to develop a wireless in-pipe inspection robot for image acquisition.\u0000\u0000\u0000Design/methodology/approach\u0000In this paper, an in-pipe robot with a new mechanical system is proposed. This system combines a three-arm load-bearing structure with spring sleeves and a half-umbrella diametric change structure, which can ensure the stability of the camera when acquiring images while maintaining the robot’s flexibility. In addition, data were transmitted wirelessly via a system that uses a 433 MHz ultra-high frequency and wireless local-area network–based image transmission system. Software and practical tests were conducted to verify the robot’s design. A preliminary examination of the robot’s cruising range was also conducted.\u0000\u0000\u0000Findings\u0000The feasibility of the robot was demonstrated using CATIA V5 and MSC ADAMS software. The simulation results showed that the centre of mass of the robot remained in a stable position and that it could function in a simulated pipeline network. In the practical test, the prototype functioned stably, correctly executed remote instructions and transmitted in near real-time its location, battery voltage and the captured images. Additionally, the tests demonstrated that the robot could successfully pass through the bends in a 200-mm-wide pipe at any angle between 0° and 90°. In actual wireless network conditions, the electrical system functioned for 44.7 consecutive minutes.\u0000\u0000\u0000Originality/value\u0000A wheeled wireless robot adopts a new mechanical system. For inspections of plastic pipelines, the robot can adapt to pipes with diameters of 150–210 mm and has the potential for practical applications.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"22 1","pages":"145-161"},"PeriodicalIF":1.8,"publicationDate":"2022-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75170485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Purpose The purpose of this study is to solve the problems of poor stability and high energy consumption of the dynamic window algorithm (DWA) for the mobile robots, a novel enhanced dynamic window algorithm is proposed in this paper. Design/methodology/approach The novel algorithm takes the distance function as the weight of the target-oriented coefficient, and a new evaluation function is presented to optimize the azimuth angle. Findings The jitter of the mobile robot caused by the drastic change of angular velocity is reduced when the robot is closer to the target point. The simulation results show that the proposed algorithm effectively optimizes the stability of the mobile robot during operation with lower angular velocity dispersion and less energy consumption, but with a slightly higher running time than DWA. Originality/value A novel enhanced dynamic window algorithm is proposed and verified. According to the experimental result, the proposed algorithm can reduce the energy consumption of the robot and improves the efficiency of the robot.
{"title":"Enhanced DWA algorithm for local path planning of mobile robot","authors":"Xin Lai, Dan Wu, Di Wu, Jia He Li, Hang Yu","doi":"10.1108/ir-05-2022-0130","DOIUrl":"https://doi.org/10.1108/ir-05-2022-0130","url":null,"abstract":"\u0000Purpose\u0000The purpose of this study is to solve the problems of poor stability and high energy consumption of the dynamic window algorithm (DWA) for the mobile robots, a novel enhanced dynamic window algorithm is proposed in this paper.\u0000\u0000\u0000Design/methodology/approach\u0000The novel algorithm takes the distance function as the weight of the target-oriented coefficient, and a new evaluation function is presented to optimize the azimuth angle.\u0000\u0000\u0000Findings\u0000The jitter of the mobile robot caused by the drastic change of angular velocity is reduced when the robot is closer to the target point. The simulation results show that the proposed algorithm effectively optimizes the stability of the mobile robot during operation with lower angular velocity dispersion and less energy consumption, but with a slightly higher running time than DWA.\u0000\u0000\u0000Originality/value\u0000A novel enhanced dynamic window algorithm is proposed and verified. According to the experimental result, the proposed algorithm can reduce the energy consumption of the robot and improves the efficiency of the robot.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"75 1","pages":"186-194"},"PeriodicalIF":1.8,"publicationDate":"2022-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79477668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zelin Wang, F. Gao, Yue Zhao, Yunpeng Yin, Liangyu Wang
Purpose Path planning is a fundamental and significant issue in robotics research, especially for the legged robots, since it is the core technology for robots to complete complex tasks such as autonomous navigation and exploration. The purpose of this paper is to propose a path planning and tracking framework for the autonomous navigation of hexapod robots. Design/methodology/approach First, a hexapod robot called Hexapod-Mini is briefly introduced. Then a path planning algorithm based on improved A* is proposed, which introduces the artificial potential field (APF) factor into the evaluation function to generate a safe and collision-free initial path. Then we apply a turning point optimization based on the greedy algorithm, which optimizes the number of turns of the path. And a fast-turning trajectory for hexapod robot is proposed, which is applied to path smoothing. Besides, a model predictive control-based motion tracking controller is used for path tracking. Findings The simulation and experiment results show that the framework can generate a safe, fast, collision-free and smooth path, and the author’s Hexapod robot can effectively track the path that demonstrates the performance of the framework. Originality/value The work presented a framework for autonomous path planning and tracking of hexapod robots. This new approach overcomes the disadvantages of the traditional path planning approach, such as lack of security, insufficient smoothness and an excessive number of turns. And the proposed method has been successfully applied to an actual hexapod robot.
{"title":"Improved A* algorithm and model predictive control- based path planning and tracking framework for hexapod robots","authors":"Zelin Wang, F. Gao, Yue Zhao, Yunpeng Yin, Liangyu Wang","doi":"10.1108/ir-01-2022-0028","DOIUrl":"https://doi.org/10.1108/ir-01-2022-0028","url":null,"abstract":"\u0000Purpose\u0000Path planning is a fundamental and significant issue in robotics research, especially for the legged robots, since it is the core technology for robots to complete complex tasks such as autonomous navigation and exploration. The purpose of this paper is to propose a path planning and tracking framework for the autonomous navigation of hexapod robots.\u0000\u0000\u0000Design/methodology/approach\u0000First, a hexapod robot called Hexapod-Mini is briefly introduced. Then a path planning algorithm based on improved A* is proposed, which introduces the artificial potential field (APF) factor into the evaluation function to generate a safe and collision-free initial path. Then we apply a turning point optimization based on the greedy algorithm, which optimizes the number of turns of the path. And a fast-turning trajectory for hexapod robot is proposed, which is applied to path smoothing. Besides, a model predictive control-based motion tracking controller is used for path tracking.\u0000\u0000\u0000Findings\u0000The simulation and experiment results show that the framework can generate a safe, fast, collision-free and smooth path, and the author’s Hexapod robot can effectively track the path that demonstrates the performance of the framework.\u0000\u0000\u0000Originality/value\u0000The work presented a framework for autonomous path planning and tracking of hexapod robots. This new approach overcomes the disadvantages of the traditional path planning approach, such as lack of security, insufficient smoothness and an excessive number of turns. And the proposed method has been successfully applied to an actual hexapod robot.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"13 1","pages":"135-144"},"PeriodicalIF":1.8,"publicationDate":"2022-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73231343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Purpose To take the advantages of terrain-adaptive capability of legged platform and fast-moving ability of wheeled platform, this paper aims to design a leg-wheel mobile platform for obstacle surmounting and analyze the feasibility and locomotivity of different moving modes. Design/methodology/approach The platform consists of six leg-wheel units. Each of the units has a close-chain mechanical leg and an actuated wheel at the end of the leg. The platform moves with two modes: legged mode and leg-wheel composite mode. The legged mode achieves high mobility driven by crank motors, while the leg-wheel composite mode achieves obstacle-surmounting ability actuated by crank motors and pitch link motors and obtains high efficiency with the hub motors. The gait planning in different modes has been carried out and the obstacle-surmounting capacity has been analyzed. Findings Based on the results of kinematic analysis and gait planning of the close-chain leg-wheel platform, the high mobility and efficiency obstacle-surmounting ability are demonstrated with the two movement modes. The feasibility of the design and the performance of the mobile platform is verified with the prototype experiment. The results of this paper show that the platform possesses good obstacle-surmounting capability. Originality/value The work presented in this paper is a novel exploration to design a close-chain leg mechanism and with an actuated wheel in series. The close-chain leg mechanism has the advantages of high leg lift and single degree of freedom characteristics, which makes the platform obtain the ability of obstacle-surmounting.
{"title":"Design and locomotion analysis of a close-chain leg-wheel mobile platform","authors":"Xiang-Ming Fan, Q. Ruan","doi":"10.1108/ir-02-2022-0046","DOIUrl":"https://doi.org/10.1108/ir-02-2022-0046","url":null,"abstract":"\u0000Purpose\u0000To take the advantages of terrain-adaptive capability of legged platform and fast-moving ability of wheeled platform, this paper aims to design a leg-wheel mobile platform for obstacle surmounting and analyze the feasibility and locomotivity of different moving modes.\u0000\u0000\u0000Design/methodology/approach\u0000The platform consists of six leg-wheel units. Each of the units has a close-chain mechanical leg and an actuated wheel at the end of the leg. The platform moves with two modes: legged mode and leg-wheel composite mode. The legged mode achieves high mobility driven by crank motors, while the leg-wheel composite mode achieves obstacle-surmounting ability actuated by crank motors and pitch link motors and obtains high efficiency with the hub motors. The gait planning in different modes has been carried out and the obstacle-surmounting capacity has been analyzed.\u0000\u0000\u0000Findings\u0000Based on the results of kinematic analysis and gait planning of the close-chain leg-wheel platform, the high mobility and efficiency obstacle-surmounting ability are demonstrated with the two movement modes. The feasibility of the design and the performance of the mobile platform is verified with the prototype experiment. The results of this paper show that the platform possesses good obstacle-surmounting capability.\u0000\u0000\u0000Originality/value\u0000The work presented in this paper is a novel exploration to design a close-chain leg mechanism and with an actuated wheel in series. The close-chain leg mechanism has the advantages of high leg lift and single degree of freedom characteristics, which makes the platform obtain the ability of obstacle-surmounting.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"7 1","pages":"122-134"},"PeriodicalIF":1.8,"publicationDate":"2022-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87275863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}