G. PreethaK., Subin K. Antony, K. R. R. Babu, S. Saritha, U. Sangeetha
Purpose This paper aims to bring in augmented reality (AR) into navigation systems to rectify the issues mentioned. This paper proposes an AR enhanced navigation system for location automated teller machine (ATM) counters (AR-ATM) and branches of banks based on user’s choice. Upon selecting the ATM, the navigational path to the destination is drawn from the current location, thereby the user can reach the ATM through the optimal path. Design/methodology/approach Traditional navigation systems require users to map with the real world environment as and when required and also may lead to incorrect path due to minor difference in distance. The traditional navigation systems’ also does not take into consideration the ergonomics and safety of the user. Findings In this system, a camera lens is used, which is directed down the street at eye level and the application displays the location of ATMs and bank branches and also provides information about the locations like distance and time through the AR superimposed object. Originality/value The application also provides indoor navigation, especially in a multi-storeyed building. Experiments are performed on smartphones that support AR, and the results are promising with no lag in time frame of the real object and virtual object. To determine the factors that regulate the suggested AR tracking mechanism, a quantitative evaluation of the experimental data is also performed. The testing of implemented AR-ATM from the standpoint of end-users is undertaken to evaluate real-time usage comfortability, and the results have been determined to be extremely satisfactory.
{"title":"Design and implementation of an augmented reality mobile application for navigating ATM counters (AR-ATM)","authors":"G. PreethaK., Subin K. Antony, K. R. R. Babu, S. Saritha, U. Sangeetha","doi":"10.1108/ir-02-2022-0051","DOIUrl":"https://doi.org/10.1108/ir-02-2022-0051","url":null,"abstract":"\u0000Purpose\u0000This paper aims to bring in augmented reality (AR) into navigation systems to rectify the issues mentioned. This paper proposes an AR enhanced navigation system for location automated teller machine (ATM) counters (AR-ATM) and branches of banks based on user’s choice. Upon selecting the ATM, the navigational path to the destination is drawn from the current location, thereby the user can reach the ATM through the optimal path.\u0000\u0000\u0000Design/methodology/approach\u0000Traditional navigation systems require users to map with the real world environment as and when required and also may lead to incorrect path due to minor difference in distance. The traditional navigation systems’ also does not take into consideration the ergonomics and safety of the user.\u0000\u0000\u0000Findings\u0000In this system, a camera lens is used, which is directed down the street at eye level and the application displays the location of ATMs and bank branches and also provides information about the locations like distance and time through the AR superimposed object.\u0000\u0000\u0000Originality/value\u0000The application also provides indoor navigation, especially in a multi-storeyed building. Experiments are performed on smartphones that support AR, and the results are promising with no lag in time frame of the real object and virtual object. To determine the factors that regulate the suggested AR tracking mechanism, a quantitative evaluation of the experimental data is also performed. The testing of implemented AR-ATM from the standpoint of end-users is undertaken to evaluate real-time usage comfortability, and the results have been determined to be extremely satisfactory.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"34 1","pages":"571-580"},"PeriodicalIF":1.8,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75201694","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 study aims to design a controller which can improve the end-effector low-frequency chattering resulting from the measurement noise and the time delay in the on-orbit tasks. The rendezvous point will move along the rendezvous ring owing to the error of the camera, and the manipulators’ collision need be avoided. In addition, owing to the dynamics coupling, the manipulators’ motion will disturb the spacecraft, and the low tracking accuracy of the end-effector needs to be improved. Design/methodology/approach This paper proposes a minimum disturbance controller based on the synchronous and adaptive acceleration planning to improve the tracking error and the disturbance energy. The synchronous and adaptive acceleration planning method plans the optimal rendezvous point and designs synchronous approaching method and provides an estimation method of the rendezvous point acceleration. A minimum disturbance controller is designed based on the energy conservation to optimize the disturbance resulting from the manipulator’s motion. Findings The acceleration planning method avoids the collision of two end-effectors and reduces the error caused by the low-frequency chattering. The minimum disturbance controller minimizes the disturbance energy of the manipulators’ motion transferred to the spacecraft. Experiment results show that the proposed method improves the low-frequency chattering, and the average position tracking error reduces by 30%, and disturbance energy reduces by 30% at least. In addition, it has good performances in the synchronous motion and adaptive tracking. Originality/value Given the immeasurability of the target satellite acceleration in space, this paper proposes an estimation method of the acceleration. This paper proposes a synchronous and adaptive acceleration planning method. In addition, the rendezvous points are optimized to avoid the two end-effectors collisions. By the energy conservation, the minimum disturbance controller is designed to ensure a satisfying tracking error and reduce the disturbance energy resulting from the manipulators’ motion.
{"title":"Minimum disturbance control based on synchronous and adaptive acceleration planning of dual-arm space robot to capture a rotating target","authors":"Qiang Liu, S. Shi, M. Jin, S. Fan, Hong Liu","doi":"10.1108/ir-12-2021-0291","DOIUrl":"https://doi.org/10.1108/ir-12-2021-0291","url":null,"abstract":"\u0000Purpose\u0000This study aims to design a controller which can improve the end-effector low-frequency chattering resulting from the measurement noise and the time delay in the on-orbit tasks. The rendezvous point will move along the rendezvous ring owing to the error of the camera, and the manipulators’ collision need be avoided. In addition, owing to the dynamics coupling, the manipulators’ motion will disturb the spacecraft, and the low tracking accuracy of the end-effector needs to be improved.\u0000\u0000\u0000Design/methodology/approach\u0000This paper proposes a minimum disturbance controller based on the synchronous and adaptive acceleration planning to improve the tracking error and the disturbance energy. The synchronous and adaptive acceleration planning method plans the optimal rendezvous point and designs synchronous approaching method and provides an estimation method of the rendezvous point acceleration. A minimum disturbance controller is designed based on the energy conservation to optimize the disturbance resulting from the manipulator’s motion.\u0000\u0000\u0000Findings\u0000The acceleration planning method avoids the collision of two end-effectors and reduces the error caused by the low-frequency chattering. The minimum disturbance controller minimizes the disturbance energy of the manipulators’ motion transferred to the spacecraft. Experiment results show that the proposed method improves the low-frequency chattering, and the average position tracking error reduces by 30%, and disturbance energy reduces by 30% at least. In addition, it has good performances in the synchronous motion and adaptive tracking.\u0000\u0000\u0000Originality/value\u0000Given the immeasurability of the target satellite acceleration in space, this paper proposes an estimation method of the acceleration. This paper proposes a synchronous and adaptive acceleration planning method. In addition, the rendezvous points are optimized to avoid the two end-effectors collisions. By the energy conservation, the minimum disturbance controller is designed to ensure a satisfying tracking error and reduce the disturbance energy resulting from the manipulators’ motion.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"418 1","pages":"1116-1132"},"PeriodicalIF":1.8,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79493974","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}
Aman Arora, Debadrata Sarkar, Arunabha Majumder, Soumen Sen, S. Roy
Purpose This paper aims to devise a first-of-its-kind methodology to determine the design, operating conditions and actuation strategy of pneumatic artificial muscles (PAMs) for assistive robotic applications. This requires extensive characterization, data set generation and meaningful modelling between PAM characteristics and design variables. Such a characterization should cover a wide range of design and operation parameters. This is a stepping stone towards generating a design guide for this highly popular compliant actuator, just like any conventional element of a mechanism. Design/methodology/approach Characterization of a large pool of custom fabricated PAMs of varying designs is performed to determine their static and dynamic behaviours. Metaheuristic optimizer-based artificial neural network (ANN) structures are used to determine eight different models representing PAM behaviour. The assistance of knee flexion during level walking is targeted for evaluating the applicability of the developed actuator by attaching a PAM across the joint. Accordingly, the PAM design and the actuation strategy are optimized through a tabletop emulator. Findings The dependence of passive length, static contraction, dynamic step response for inflation and deflation of the PAMs on their design dimensions and operating parameters is successfully modelled by the ANNs. The efficacy of these models is investigated to successfully optimize the PAM design, operation parameters and actuation strategy for using a PAM in assisting knee flexion in human gait. Originality/value Characterization of static and the dynamic behaviour of a large pool of PAMs with varying designs over a wide range of operating conditions is the novel feature in this article. A lucid customizable fabrication technique is discussed to obtain a wide variety of PAM designs. Metaheuristic-based ANNs are used for tackling high non-linearity in data while modelling the PAM behaviour. An innovative tabletop emulator is used for investigating the utility of the models in the possible application of PAMs in assistive robotics.
{"title":"Hybridized neural network inspired behavioural modelling of pneumatic artificial muscles for assistive robotic applications","authors":"Aman Arora, Debadrata Sarkar, Arunabha Majumder, Soumen Sen, S. Roy","doi":"10.1108/ir-03-2022-0060","DOIUrl":"https://doi.org/10.1108/ir-03-2022-0060","url":null,"abstract":"\u0000Purpose\u0000This paper aims to devise a first-of-its-kind methodology to determine the design, operating conditions and actuation strategy of pneumatic artificial muscles (PAMs) for assistive robotic applications. This requires extensive characterization, data set generation and meaningful modelling between PAM characteristics and design variables. Such a characterization should cover a wide range of design and operation parameters. This is a stepping stone towards generating a design guide for this highly popular compliant actuator, just like any conventional element of a mechanism.\u0000\u0000\u0000Design/methodology/approach\u0000Characterization of a large pool of custom fabricated PAMs of varying designs is performed to determine their static and dynamic behaviours. Metaheuristic optimizer-based artificial neural network (ANN) structures are used to determine eight different models representing PAM behaviour. The assistance of knee flexion during level walking is targeted for evaluating the applicability of the developed actuator by attaching a PAM across the joint. Accordingly, the PAM design and the actuation strategy are optimized through a tabletop emulator.\u0000\u0000\u0000Findings\u0000The dependence of passive length, static contraction, dynamic step response for inflation and deflation of the PAMs on their design dimensions and operating parameters is successfully modelled by the ANNs. The efficacy of these models is investigated to successfully optimize the PAM design, operation parameters and actuation strategy for using a PAM in assisting knee flexion in human gait.\u0000\u0000\u0000Originality/value\u0000Characterization of static and the dynamic behaviour of a large pool of PAMs with varying designs over a wide range of operating conditions is the novel feature in this article. A lucid customizable fabrication technique is discussed to obtain a wide variety of PAM designs. Metaheuristic-based ANNs are used for tackling high non-linearity in data while modelling the PAM behaviour. An innovative tabletop emulator is used for investigating the utility of the models in the possible application of PAMs in assistive robotics.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"87 1","pages":"56-69"},"PeriodicalIF":1.8,"publicationDate":"2022-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84070652","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 Branched articulated robots (BARs) are highly non-linear systems; accurate dynamic identification is critical for model-based control in high-speed and heavy-load applications. However, due to some dynamic parameters being redundant, dynamic models are singular, which increases the calculation amount and reduces the robustness of identification. This paper aims to propose a novel methodology for the dynamic analysis and redundant parameters elimination of BARs. Design/methodology/approach At first, the motion of a rigid body is divided into constraint-dependent and constraint-independent. The redundancy of inertial parameters is analyzed from physical constraints. Then, the redundant parameters are eliminated by mapping posterior links to their antecedents, which can be applied for re-deriving the Newton–Euler formulas. Finally, through parameter transformation, the presented dynamic model is non-singular and available for identification directly. Findings New formulas for redundant parameters elimination are explicit and computationally efficient. This unifies the redundant parameters elimination of prismatic and revolute joints for BARs, and it is also applicable to other types of joints containing constraints. The proposed approach is conducive to facilitating the modelling phase during the robot identification. Simulation studies are conducted to illustrate the effectiveness of the proposed redundant parameters elimination and non-singular dynamic model determination. Experimental studies are carried out to verify the result of the identification algorithm. Originality/value This work proposes to determine and directly identify the non-redundant dynamic model of robots, which can help to reduce the procedure of obtaining the reversible regression matrix for identification.
{"title":"Non-redundant inertial parameters determination for dynamic identification of branched articulated robots","authors":"Chao Tan, Huan Zhao, H. Ding","doi":"10.1108/ir-12-2021-0296","DOIUrl":"https://doi.org/10.1108/ir-12-2021-0296","url":null,"abstract":"\u0000Purpose\u0000Branched articulated robots (BARs) are highly non-linear systems; accurate dynamic identification is critical for model-based control in high-speed and heavy-load applications. However, due to some dynamic parameters being redundant, dynamic models are singular, which increases the calculation amount and reduces the robustness of identification. This paper aims to propose a novel methodology for the dynamic analysis and redundant parameters elimination of BARs.\u0000\u0000\u0000Design/methodology/approach\u0000At first, the motion of a rigid body is divided into constraint-dependent and constraint-independent. The redundancy of inertial parameters is analyzed from physical constraints. Then, the redundant parameters are eliminated by mapping posterior links to their antecedents, which can be applied for re-deriving the Newton–Euler formulas. Finally, through parameter transformation, the presented dynamic model is non-singular and available for identification directly.\u0000\u0000\u0000Findings\u0000New formulas for redundant parameters elimination are explicit and computationally efficient. This unifies the redundant parameters elimination of prismatic and revolute joints for BARs, and it is also applicable to other types of joints containing constraints. The proposed approach is conducive to facilitating the modelling phase during the robot identification. Simulation studies are conducted to illustrate the effectiveness of the proposed redundant parameters elimination and non-singular dynamic model determination. Experimental studies are carried out to verify the result of the identification algorithm.\u0000\u0000\u0000Originality/value\u0000This work proposes to determine and directly identify the non-redundant dynamic model of robots, which can help to reduce the procedure of obtaining the reversible regression matrix for identification.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"55 1","pages":"1229-1241"},"PeriodicalIF":1.8,"publicationDate":"2022-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81931038","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 provide an insight into light detection and ranging (lidar) technology and its growing applications in robotics. Design/methodology/approach Following a short introduction, this paper first describes the main lidar techniques and then provides details of a selection of recent academic and corporate research and development activities. This is followed by a discussion of existing and emerging applications. Finally, conclusions are drawn. Findings Lidar technology has been the topic of extensive development activity and several principles which differ from the original concept have been commercialised. Lidars are used in all manner of autonomous mobile robots (AMRs) across a broad sector of industries for navigation and have recently started to penetrate the domestic robot market. They have the potential to play a central role in the emerging families of driverless passenger cars and commercial vehicles. In the future, the markets for lidar are expected to expand dramatically as the technology continues to evolve and improve and autonomous vehicles, AMRs and drones become ever-more commonplace. Originality/value This paper illustrates the growing importance of lidar to robotics by providing details of the technology, developments and applications.
{"title":"The growing importance of lidar technology","authors":"R. Bogue","doi":"10.1108/ir-05-2022-0138","DOIUrl":"https://doi.org/10.1108/ir-05-2022-0138","url":null,"abstract":"\u0000Purpose\u0000This paper aims to provide an insight into light detection and ranging (lidar) technology and its growing applications in robotics.\u0000\u0000\u0000Design/methodology/approach\u0000Following a short introduction, this paper first describes the main lidar techniques and then provides details of a selection of recent academic and corporate research and development activities. This is followed by a discussion of existing and emerging applications. Finally, conclusions are drawn.\u0000\u0000\u0000Findings\u0000Lidar technology has been the topic of extensive development activity and several principles which differ from the original concept have been commercialised. Lidars are used in all manner of autonomous mobile robots (AMRs) across a broad sector of industries for navigation and have recently started to penetrate the domestic robot market. They have the potential to play a central role in the emerging families of driverless passenger cars and commercial vehicles. In the future, the markets for lidar are expected to expand dramatically as the technology continues to evolve and improve and autonomous vehicles, AMRs and drones become ever-more commonplace.\u0000\u0000\u0000Originality/value\u0000This paper illustrates the growing importance of lidar to robotics by providing details of the technology, developments and applications.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"5 1","pages":"1025-1031"},"PeriodicalIF":1.8,"publicationDate":"2022-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79573986","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}
Compliant and dexterous manipulation forms the basis for efficient robotic interaction in dynamic and unstructured environments. When manipulators are deployed in a dynamic and unstructured environment, they are required to have more adaptivity and dexterity in addition to high precision control. Although we have seen many promising robotic manipulations in well-controlled laboratory environments, compliant dexterous manipulation, as an essential robotic skill that can be applied in a less strict scenario, e.g. in a living room, is far from being solved. The remaining problems motivate researchers to develop advanced technologies that combine optimized design, intelligent perception, interaction and learning to fill the gap between manipulation theory and its application in the real world. As one of the most important motion interfaces, human hands endow human dexterity when interacting with external environments. It is the life-long mission for many robotic scientists and engineers to develop a human-like dexterous robotic hand. However, there exist many R&D challenges for such robotic hands in regard to mechanical structure, modal fusion and control-learning aspects. First, from the robotic hand designing aspect, the developer needs a balance between the hand’s light weight and the volume to accommodate all required actuators, sensors and mechanics to realize humanlike motion. Second, from the perception aspect, how to design the robust state observer by fusion multimodality feedback is an open challenge, especially when the environments and the given tasks are dynamic. Finally, promising off-the-shelf AI approaches cannot be quickly transferred to the robot control domain. The learning-based method requires a large amount of data, which is not readily available for contact-richmanipulation tasks. This special issue includes the most cutting-edge research results on the abovementioned problems. It contains six research articles that present the newest research achievements regarding the above challenges: The first two focus on dexterous hand design. The third and fourth ones are on perception recognition. The remaining two papers study control and learning. The first paper (Bai et al., 2022) proposes a humanoid robot hand that could wear spacesuit gloves and thus performed measurements. The robot hand consisted of five modular fingers and a parallel wrist driven by a linear motor. Compared with traditional robotic hands, the fingers and wrist were fitted into a spacesuit glove and assembled inside. The humanoid design boosted the dexterity performance of the robotic hand. With the simplification of design and control, the minimalist design radically reduced the complexity of the system and improved the dexterity of the hands. The second paper (Liu et al., 2022) proposes a soft actuator with a sponge-based actuating structure and a layer-jammingbased stiffness to improve the structure in a cavity. The soft actuator was bent under vacuum pressure
{"title":"Guest editorial: Dexterous manipulation","authors":"Bin Fang, Qiang Li, Fei Chen, Weiwei Wan","doi":"10.1108/ir-06-2022-460","DOIUrl":"https://doi.org/10.1108/ir-06-2022-460","url":null,"abstract":"Compliant and dexterous manipulation forms the basis for efficient robotic interaction in dynamic and unstructured environments. When manipulators are deployed in a dynamic and unstructured environment, they are required to have more adaptivity and dexterity in addition to high precision control. Although we have seen many promising robotic manipulations in well-controlled laboratory environments, compliant dexterous manipulation, as an essential robotic skill that can be applied in a less strict scenario, e.g. in a living room, is far from being solved. The remaining problems motivate researchers to develop advanced technologies that combine optimized design, intelligent perception, interaction and learning to fill the gap between manipulation theory and its application in the real world. As one of the most important motion interfaces, human hands endow human dexterity when interacting with external environments. It is the life-long mission for many robotic scientists and engineers to develop a human-like dexterous robotic hand. However, there exist many R&D challenges for such robotic hands in regard to mechanical structure, modal fusion and control-learning aspects. First, from the robotic hand designing aspect, the developer needs a balance between the hand’s light weight and the volume to accommodate all required actuators, sensors and mechanics to realize humanlike motion. Second, from the perception aspect, how to design the robust state observer by fusion multimodality feedback is an open challenge, especially when the environments and the given tasks are dynamic. Finally, promising off-the-shelf AI approaches cannot be quickly transferred to the robot control domain. The learning-based method requires a large amount of data, which is not readily available for contact-richmanipulation tasks. This special issue includes the most cutting-edge research results on the abovementioned problems. It contains six research articles that present the newest research achievements regarding the above challenges: The first two focus on dexterous hand design. The third and fourth ones are on perception recognition. The remaining two papers study control and learning. The first paper (Bai et al., 2022) proposes a humanoid robot hand that could wear spacesuit gloves and thus performed measurements. The robot hand consisted of five modular fingers and a parallel wrist driven by a linear motor. Compared with traditional robotic hands, the fingers and wrist were fitted into a spacesuit glove and assembled inside. The humanoid design boosted the dexterity performance of the robotic hand. With the simplification of design and control, the minimalist design radically reduced the complexity of the system and improved the dexterity of the hands. The second paper (Liu et al., 2022) proposes a soft actuator with a sponge-based actuating structure and a layer-jammingbased stiffness to improve the structure in a cavity. The soft actuator was bent under vacuum pressure","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"51 1","pages":"601-602"},"PeriodicalIF":1.8,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78322244","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 sensorless external force estimation of robot manipulator can be helpful for reducing the cost and complexity of the robot system. However, the complex friction phenomenon of the robot joint and uncertainty of robot model and signal noise significantly decrease the estimation accuracy. This study aims to investigate the friction modeling and the noise rejection of the external force estimation. Design/methodology/approach A LuGre-linear-hybrid (LuGre-L) friction model that combines the dynamic friction characteristics of the robot joint and static friction of the drive motor is proposed to improve the modeling accuracy of robot friction. The square root cubature Kalman filter (SCKF) is improved by integrating a Sage Window outer layer and a nonlinear disturbance observer (NDOB) inner layer. In the outer layer, Sage Window is integrated in the square root Kalman filter (W-SCKF) to dynamically adjust noise statistics. NDOB is applied as the inner layer of W-SCKF (NDOB-WSCKF) to obtain the uncertain state variables of the state model. Findings A peg-in-hole contact experiment conducted on a real robot demonstrates that the average accuracy of the estimated joint torque based on LuGre-L is improved by 4.9% in contrast to the LuGre model. Based on the proposed NDOB-WSCKF, the average estimation accuracy of the external joint torque can reach up to 92.1%, which is improved by 4%–15.3% in contrast to other estimation methods (SCKF and NDOB). Originality/value A LuGre-L friction model is proposed to handle the coupling of static and dynamic friction characteristics for the robot manipulator. An improved SCKF is applied to estimate the external force of the robot manipulator. To improve the noise rejection ability of the estimation method and make it more resistant to unmodeled state variable, SCKF is improved by integrating a Sage Window and NDOB, and a NDOB-WSCKF external force estimator is developed. Validation results demonstrate that the accuracy of the robot dynamics model and the estimated external force is improved by the proposed method.
{"title":"External force estimation for robot manipulator based on a LuGre-linear-hybrid friction model and an improved square root cubature Kalman filter","authors":"Jiacai Wang, Jiaoliao Chen, Libin Zhang, Fang Xu, Lewei Zhi","doi":"10.1108/ir-03-2022-0057","DOIUrl":"https://doi.org/10.1108/ir-03-2022-0057","url":null,"abstract":"\u0000Purpose\u0000The sensorless external force estimation of robot manipulator can be helpful for reducing the cost and complexity of the robot system. However, the complex friction phenomenon of the robot joint and uncertainty of robot model and signal noise significantly decrease the estimation accuracy. This study aims to investigate the friction modeling and the noise rejection of the external force estimation.\u0000\u0000\u0000Design/methodology/approach\u0000A LuGre-linear-hybrid (LuGre-L) friction model that combines the dynamic friction characteristics of the robot joint and static friction of the drive motor is proposed to improve the modeling accuracy of robot friction. The square root cubature Kalman filter (SCKF) is improved by integrating a Sage Window outer layer and a nonlinear disturbance observer (NDOB) inner layer. In the outer layer, Sage Window is integrated in the square root Kalman filter (W-SCKF) to dynamically adjust noise statistics. NDOB is applied as the inner layer of W-SCKF (NDOB-WSCKF) to obtain the uncertain state variables of the state model.\u0000\u0000\u0000Findings\u0000A peg-in-hole contact experiment conducted on a real robot demonstrates that the average accuracy of the estimated joint torque based on LuGre-L is improved by 4.9% in contrast to the LuGre model. Based on the proposed NDOB-WSCKF, the average estimation accuracy of the external joint torque can reach up to 92.1%, which is improved by 4%–15.3% in contrast to other estimation methods (SCKF and NDOB).\u0000\u0000\u0000Originality/value\u0000A LuGre-L friction model is proposed to handle the coupling of static and dynamic friction characteristics for the robot manipulator. An improved SCKF is applied to estimate the external force of the robot manipulator. To improve the noise rejection ability of the estimation method and make it more resistant to unmodeled state variable, SCKF is improved by integrating a Sage Window and NDOB, and a NDOB-WSCKF external force estimator is developed. Validation results demonstrate that the accuracy of the robot dynamics model and the estimated external force is improved by the proposed method.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"13 1","pages":"11-25"},"PeriodicalIF":1.8,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85993900","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 paper aims to reduce the low-frequency resonance and residual vibration of the robot during the operation, improve the working accuracy and efficiency. A reduced weight and large load-to-weight ratio can improve the practical application of a collaborative robot. However, flexibility caused by the reduced weight and large load-to-weight ratio leads to low-frequency resonance and residual vibration during the operation of the robot, which reduces the working accuracy and efficiency. The vibrations of the collaborative robot are suppressed using a modified trajectory-planning method. Design/methodology/approach A rigid-flexible coupling dynamics model of the collaborative robot is established using the finite element and Lagrange methods, and the vibration equation of the robot is derived. Trajectory planning is performed with the excitation force as the optimization objective, and the trajectory planning method is modified to reduce the vibration of the collaborative robot and ensure the precision of the robot terminal. Findings The vibration amplitude is reduced by 80%. The maximum torque amplitude of the joint before the vibration suppression reaches 50 N·m. After vibration suppression, the maximum torque amplitude of the joint is 10 N·m, and the resonance phenomenon is eliminated during the operation process. Consequently, the effectiveness of the modified trajectory planning method is verified, where the vibration and residual vibration in the movement of the collaborative robot are significantly reduced, and the positioning accuracy and working efficiency of the robot are improved. Originality/value This method can greatly reduce the vibration and residual vibration of the collaborative robot, improve the positioning accuracy and work efficiency and promote the rapid application and development of collaborative robots in the industrial and service fields.
{"title":"Vibration suppression of collaborative robot based on modified trajectory planning","authors":"Y. Tian, Xiang Yue, Lin Wang, Yan Feng","doi":"10.1108/ir-01-2022-0017","DOIUrl":"https://doi.org/10.1108/ir-01-2022-0017","url":null,"abstract":"\u0000Purpose\u0000The paper aims to reduce the low-frequency resonance and residual vibration of the robot during the operation, improve the working accuracy and efficiency. A reduced weight and large load-to-weight ratio can improve the practical application of a collaborative robot. However, flexibility caused by the reduced weight and large load-to-weight ratio leads to low-frequency resonance and residual vibration during the operation of the robot, which reduces the working accuracy and efficiency. The vibrations of the collaborative robot are suppressed using a modified trajectory-planning method.\u0000\u0000\u0000Design/methodology/approach\u0000A rigid-flexible coupling dynamics model of the collaborative robot is established using the finite element and Lagrange methods, and the vibration equation of the robot is derived. Trajectory planning is performed with the excitation force as the optimization objective, and the trajectory planning method is modified to reduce the vibration of the collaborative robot and ensure the precision of the robot terminal.\u0000\u0000\u0000Findings\u0000The vibration amplitude is reduced by 80%. The maximum torque amplitude of the joint before the vibration suppression reaches 50 N·m. After vibration suppression, the maximum torque amplitude of the joint is 10 N·m, and the resonance phenomenon is eliminated during the operation process. Consequently, the effectiveness of the modified trajectory planning method is verified, where the vibration and residual vibration in the movement of the collaborative robot are significantly reduced, and the positioning accuracy and working efficiency of the robot are improved.\u0000\u0000\u0000Originality/value\u0000This method can greatly reduce the vibration and residual vibration of the collaborative robot, improve the positioning accuracy and work efficiency and promote the rapid application and development of collaborative robots in the industrial and service fields.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"79 1","pages":"45-55"},"PeriodicalIF":1.8,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82936131","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 propose an overall deformation rolling mechanism based on double four-link mechanism. The double quadrilateral mobile mechanism (DQMM) has two switchable working modes which can be used to traverse different terrains or climb over obstacles. Design/methodology/approach The main body of the DQMM is composed of a double four-link mechanism which sharing a public link and two symmetrical steering platforms which placed at both ends of the four-link mechanism. The steering platforms give the DQMM not only steering ability but also reconnaissance ability which can be achieved by carrying sensors such as cameras on steering platforms. By controlling the deformation of the DQMM, it can switch between two working modes (tracked rolling mode and obstacle-climbing mode) to achieve the functions of rolling and obstacle-climbing. Dynamic simulation model was established to verify the feasibility. Findings Based on the kinematics analysis and simulation results of the DQMM, its moving function is realized by the tracked rolling mode, and the obstacle-climbing mode is used to climb over obstacles in structured terrains such as continuous stairs. The feasibility of the two working modes is verified on a physical prototype. Originality/value The work of this paper is a new exploration of applying “overall closed moving linkages mechanism” to the area of small mobile mechanisms. The adaptability of different terrains and the ability of obstacle-climbing are improved by the combination of multi-modes.
{"title":"Design and motion analysis of double quadrilateral mobile mechanism","authors":"Junlin Cheng, Peiyu Ma, Q. Ruan, Yezhuo Li, Qianqian Zhang","doi":"10.1108/ir-12-2021-0290","DOIUrl":"https://doi.org/10.1108/ir-12-2021-0290","url":null,"abstract":"\u0000Purpose\u0000The purpose of this paper is to propose an overall deformation rolling mechanism based on double four-link mechanism. The double quadrilateral mobile mechanism (DQMM) has two switchable working modes which can be used to traverse different terrains or climb over obstacles.\u0000\u0000\u0000Design/methodology/approach\u0000The main body of the DQMM is composed of a double four-link mechanism which sharing a public link and two symmetrical steering platforms which placed at both ends of the four-link mechanism. The steering platforms give the DQMM not only steering ability but also reconnaissance ability which can be achieved by carrying sensors such as cameras on steering platforms. By controlling the deformation of the DQMM, it can switch between two working modes (tracked rolling mode and obstacle-climbing mode) to achieve the functions of rolling and obstacle-climbing. Dynamic simulation model was established to verify the feasibility.\u0000\u0000\u0000Findings\u0000Based on the kinematics analysis and simulation results of the DQMM, its moving function is realized by the tracked rolling mode, and the obstacle-climbing mode is used to climb over obstacles in structured terrains such as continuous stairs. The feasibility of the two working modes is verified on a physical prototype.\u0000\u0000\u0000Originality/value\u0000The work of this paper is a new exploration of applying “overall closed moving linkages mechanism” to the area of small mobile mechanisms. The adaptability of different terrains and the ability of obstacle-climbing are improved by the combination of multi-modes.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"7 1","pages":"1256-1269"},"PeriodicalIF":1.8,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79041324","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}
Yuliang Guo, Jianwei Niu, Renluan Hou, Tao Ren, Bing Han, Xiaolong Yu, Qun Ma
Purpose Sensorless passive lead-through programming (LTP) is a promising physical human-robot interaction technology that enables manual trajectory demonstrations based on gravity and friction compensation. The major difficulty lies in static friction compensation during LTP start-up. Instead of static friction compensation, conventional methods only compensate for Coulomb friction after the joint velocity exceeds a threshold. Therefore, conventional start-up external torques must overcome static friction. When the static friction is considerable, it is difficult for conventional LTP to start up and make small movements. This paper aims to decrease the start-up external torque and improve the small movement performance. Design/methodology/approach This paper reveals a novel usage of a high-gain position-loop in industrial robot applications aimed at sensitively detecting external torque during start-up. Then, the static friction is partly compensated by Coulomb friction to facilitate start-up. In addition, a detailed transition method between the proposed start-up and conventional passive LTP is proposed based on a finite state machine. Findings Experiments are implemented on the ROKAE XB4 robot to verify the effectiveness of the proposed external torque detection. Compared with the conventional LTP method, the proposed LTP method significantly decreases the start-up external torque and facilitates small movements. Originality/value This paper proposes and verifies a novel start-up method of sensorless LTP based on a start-up external torque detection and a transition method between start-up and conventional LTP. This research improves the LTP start-up performance, especially for industrial robots with large static friction.
{"title":"A novel start-up method of sensorless passive lead-through programming for industrial robots","authors":"Yuliang Guo, Jianwei Niu, Renluan Hou, Tao Ren, Bing Han, Xiaolong Yu, Qun Ma","doi":"10.1108/ir-02-2022-0034","DOIUrl":"https://doi.org/10.1108/ir-02-2022-0034","url":null,"abstract":"\u0000Purpose\u0000Sensorless passive lead-through programming (LTP) is a promising physical human-robot interaction technology that enables manual trajectory demonstrations based on gravity and friction compensation. The major difficulty lies in static friction compensation during LTP start-up. Instead of static friction compensation, conventional methods only compensate for Coulomb friction after the joint velocity exceeds a threshold. Therefore, conventional start-up external torques must overcome static friction. When the static friction is considerable, it is difficult for conventional LTP to start up and make small movements. This paper aims to decrease the start-up external torque and improve the small movement performance.\u0000\u0000\u0000Design/methodology/approach\u0000This paper reveals a novel usage of a high-gain position-loop in industrial robot applications aimed at sensitively detecting external torque during start-up. Then, the static friction is partly compensated by Coulomb friction to facilitate start-up. In addition, a detailed transition method between the proposed start-up and conventional passive LTP is proposed based on a finite state machine.\u0000\u0000\u0000Findings\u0000Experiments are implemented on the ROKAE XB4 robot to verify the effectiveness of the proposed external torque detection. Compared with the conventional LTP method, the proposed LTP method significantly decreases the start-up external torque and facilitates small movements.\u0000\u0000\u0000Originality/value\u0000This paper proposes and verifies a novel start-up method of sensorless LTP based on a start-up external torque detection and a transition method between start-up and conventional LTP. This research improves the LTP start-up performance, especially for industrial robots with large static friction.\u0000","PeriodicalId":54987,"journal":{"name":"Industrial Robot-The International Journal of Robotics Research and Application","volume":"223 1","pages":"26-34"},"PeriodicalIF":1.8,"publicationDate":"2022-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83478384","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}