Pub Date : 2024-01-01DOI: 10.1177/17298806231218789
Hongzhi Tian, Jirong Wang
Model-based stereo vision pose estimation depends on the establishment of the model. The photo-model-based method simplifies the model-building process with just one photo. Programming languages do not predefine the shapes, colors, and patterns of objects. In the past, however, it was necessary to calculate a pixel per metric ratio, that is, the number of pixels per millimeter of the object, based on the photo’s shooting distance to generate a photo-model with the same size (length and width) as the actual object. It restricts the real application. The proposed method extends the traditional photo-modeling algorithm and relaxes the photo prerequisite for target pose determination. Various pixel per metric ratios will be assumed to generate 3D photo-models of different sizes. These models will then be employed in stereo vision image matching techniques to detect the pose of the target object. Since it is not a data-driven method, it does not require many pictures and pretraining time. This article applies the algorithm to the cleaning of seaports and aquaculture, aiming to locate dead or diseased marine life on the water surface before collection. Pose estimation experiments have been conducted to detect an object’s pose and a prepared photo’s pixel per metric ratio in real application scenarios. The results show that the expanded photo-model stereo vision method can estimate the pose of a target with one pixel per metric ratio unknown photo.
{"title":"Expanded photo-model-based stereo vision pose estimation using a shooting distance unknown photo","authors":"Hongzhi Tian, Jirong Wang","doi":"10.1177/17298806231218789","DOIUrl":"https://doi.org/10.1177/17298806231218789","url":null,"abstract":"Model-based stereo vision pose estimation depends on the establishment of the model. The photo-model-based method simplifies the model-building process with just one photo. Programming languages do not predefine the shapes, colors, and patterns of objects. In the past, however, it was necessary to calculate a pixel per metric ratio, that is, the number of pixels per millimeter of the object, based on the photo’s shooting distance to generate a photo-model with the same size (length and width) as the actual object. It restricts the real application. The proposed method extends the traditional photo-modeling algorithm and relaxes the photo prerequisite for target pose determination. Various pixel per metric ratios will be assumed to generate 3D photo-models of different sizes. These models will then be employed in stereo vision image matching techniques to detect the pose of the target object. Since it is not a data-driven method, it does not require many pictures and pretraining time. This article applies the algorithm to the cleaning of seaports and aquaculture, aiming to locate dead or diseased marine life on the water surface before collection. Pose estimation experiments have been conducted to detect an object’s pose and a prepared photo’s pixel per metric ratio in real application scenarios. The results show that the expanded photo-model stereo vision method can estimate the pose of a target with one pixel per metric ratio unknown photo.","PeriodicalId":50343,"journal":{"name":"International Journal of Advanced Robotic Systems","volume":"36 8","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139455645","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}
Pub Date : 2024-01-01DOI: 10.1177/17298806231218865
Xiaoxu Du, Yongsheng Qi, Junfeng Zhu, Yongting Li, Liqiang Liu
There are problems in the special pastoral environment, including large changes in target size and serious interference from light and environmental factors. To solve the above problems, an enhanced YOLOv4-tiny target detection network is proposed in this study. This network first solves the problem of livestock size fluctuation in pastoral areas, uses a pyramid network with multiscale feature fusion, and considers shallow local detail features and deep semantic information. Subsequently, a novel compound multichannel attention mechanism is proposed to increase the accuracy of the target detection network for the pastoral environment. The problem of poor accuracy of target detection network is solved. The algorithm is ported to Jetson AGX embedded platform for validation to examine the real-time performance of the algorithm. As revealed by the experimental results, enhanced YOLOv4-tiny achieves 89.77% detection accuracy and 30 frames/second detection speed, which increases the average detection accuracy by 11.67% compared with the conventional YOLOv4-tiny while maintaining almost the same detection rate.
{"title":"Enhanced lightweight deep network for efficient livestock detection in grazing areas","authors":"Xiaoxu Du, Yongsheng Qi, Junfeng Zhu, Yongting Li, Liqiang Liu","doi":"10.1177/17298806231218865","DOIUrl":"https://doi.org/10.1177/17298806231218865","url":null,"abstract":"There are problems in the special pastoral environment, including large changes in target size and serious interference from light and environmental factors. To solve the above problems, an enhanced YOLOv4-tiny target detection network is proposed in this study. This network first solves the problem of livestock size fluctuation in pastoral areas, uses a pyramid network with multiscale feature fusion, and considers shallow local detail features and deep semantic information. Subsequently, a novel compound multichannel attention mechanism is proposed to increase the accuracy of the target detection network for the pastoral environment. The problem of poor accuracy of target detection network is solved. The algorithm is ported to Jetson AGX embedded platform for validation to examine the real-time performance of the algorithm. As revealed by the experimental results, enhanced YOLOv4-tiny achieves 89.77% detection accuracy and 30 frames/second detection speed, which increases the average detection accuracy by 11.67% compared with the conventional YOLOv4-tiny while maintaining almost the same detection rate.","PeriodicalId":50343,"journal":{"name":"International Journal of Advanced Robotic Systems","volume":"26 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139456084","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}
Pub Date : 2023-11-01DOI: 10.1177/17298806231210665
Zhihong Zou
Manipulability quantification and evaluation of robot manipulators plays an important role in robotic mechanism design, motion planning, and control. In this article, a general methodology of using manipulability polytopes to characterize the manipulator’s capability to generate velocities, forces, and accelerations at the end-effector is proposed. This methodology can be used to determine the kinematic, mechanical, and dynamic manipulability of both redundant and nonredundant serial manipulators, where influences of gravity, joint velocities and accelerations, and end-effector payload on the dynamic manipulability are incorporated into the derivation of the manipulability polytopes. Since the manipulability polytope is the feasible region defined by all the joint constraints, the proposed method is suitable for solving the problems including both symmetric and asymmetric joint constraints. Furthermore, a systematic architecture and detailed procedures for performance computation with respect to different types of manipulability of serial robot manipulators are presented. Two typical application examples, respectively, for two and three degree-of-freedom planar manipulators are given to illustrate the correctness and capability of the proposed methodology.
{"title":"A general method for the manipulability analysis of serial robot manipulators","authors":"Zhihong Zou","doi":"10.1177/17298806231210665","DOIUrl":"https://doi.org/10.1177/17298806231210665","url":null,"abstract":"Manipulability quantification and evaluation of robot manipulators plays an important role in robotic mechanism design, motion planning, and control. In this article, a general methodology of using manipulability polytopes to characterize the manipulator’s capability to generate velocities, forces, and accelerations at the end-effector is proposed. This methodology can be used to determine the kinematic, mechanical, and dynamic manipulability of both redundant and nonredundant serial manipulators, where influences of gravity, joint velocities and accelerations, and end-effector payload on the dynamic manipulability are incorporated into the derivation of the manipulability polytopes. Since the manipulability polytope is the feasible region defined by all the joint constraints, the proposed method is suitable for solving the problems including both symmetric and asymmetric joint constraints. Furthermore, a systematic architecture and detailed procedures for performance computation with respect to different types of manipulability of serial robot manipulators are presented. Two typical application examples, respectively, for two and three degree-of-freedom planar manipulators are given to illustrate the correctness and capability of the proposed methodology.","PeriodicalId":50343,"journal":{"name":"International Journal of Advanced Robotic Systems","volume":"39 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139304318","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}
Pub Date : 2023-11-01DOI: 10.1177/17298806231213442
Ziyue Li, Xianju Yuan, Zhanpeng Yang
The end effector characterizing a flipping–cutting way is designed firstly for picking spherical fruits with a good universality, which is mainly composed of three parts such as a clamping mechanism, a flipping mechanism, and a cutting mechanism. Subsequently, the kinematics simulation for the clamping mechanism, flipping mechanism, and cutting mechanism will be implemented by mathematical models and the ADAMS software, and results reflected through them are consistent with each other, thus presenting the feasibility of the structural scheme and two models. On the basis of scheme and results of models, the sample of the end effector is manufactured. Finally, picking experiments in a lab will be also conducted in view of diverse indexes, such as the successful grabbing action, flipping–cutting action, flipping–breaking action, average fruit picking time, success rate, and damage rate. It is drawn from experimental results that the success rate of grabbing is 100%, and a success rate for picking is over 80%. An average picking time is about 9.6s, and very few fruits are damaged. Therefore, such a scheme is feasible, further presenting a good reference for designing the entire robot in a field of picking diverse spherical fruits.
{"title":"Design, simulation, and experiment for the end effector of a spherical fruit picking robot","authors":"Ziyue Li, Xianju Yuan, Zhanpeng Yang","doi":"10.1177/17298806231213442","DOIUrl":"https://doi.org/10.1177/17298806231213442","url":null,"abstract":"The end effector characterizing a flipping–cutting way is designed firstly for picking spherical fruits with a good universality, which is mainly composed of three parts such as a clamping mechanism, a flipping mechanism, and a cutting mechanism. Subsequently, the kinematics simulation for the clamping mechanism, flipping mechanism, and cutting mechanism will be implemented by mathematical models and the ADAMS software, and results reflected through them are consistent with each other, thus presenting the feasibility of the structural scheme and two models. On the basis of scheme and results of models, the sample of the end effector is manufactured. Finally, picking experiments in a lab will be also conducted in view of diverse indexes, such as the successful grabbing action, flipping–cutting action, flipping–breaking action, average fruit picking time, success rate, and damage rate. It is drawn from experimental results that the success rate of grabbing is 100%, and a success rate for picking is over 80%. An average picking time is about 9.6s, and very few fruits are damaged. Therefore, such a scheme is feasible, further presenting a good reference for designing the entire robot in a field of picking diverse spherical fruits.","PeriodicalId":50343,"journal":{"name":"International Journal of Advanced Robotic Systems","volume":"38 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139306263","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}
Pub Date : 2023-11-01DOI: 10.1177/17298806231216798
Shuangji Yao, Zhilong Wang, M. Ceccarelli, Haojie Yang, Dingxuan Zhao
The manipulate load system of a helicopter driving simulator is a complex mechatronic system. To simulate the load system of the joystick more effectively, this study provides a new manipulate mechanism with automatic position reset function that integrates a spring system within the joystick. The load simulation of this manipulate mechanism can be achieved by designing the nonlinear coefficient of the spring in a reasonable manner, thereby eliminating the need for complex control of motor simulation and system time delay. This greatly simplifies the complexity of the system and effectively meets the requirements of real-time and accuracy. Initially, the new manipulate mechanism is described in detail through kinematic analysis. Then, dynamic simulation is conducted in ADAMS software to simulate the motion of the operation mechanism. Considering the active–passive relationships between the manipulate mechanism and the driving simulator, a mapping is established to achieve synchronized motion. The synchronized motion is subsequently evaluated and verified in MATLAB/Simulink. The results reveal that this new manipulate mechanism has high reliability and can effectively achieve synchronized motion with the driving simulator. The new manipulate mechanism will be useful in advancing research into the design of manipulate mechanism processes.
{"title":"Manipulate mechanism design and synchronous motion application for driving simulator","authors":"Shuangji Yao, Zhilong Wang, M. Ceccarelli, Haojie Yang, Dingxuan Zhao","doi":"10.1177/17298806231216798","DOIUrl":"https://doi.org/10.1177/17298806231216798","url":null,"abstract":"The manipulate load system of a helicopter driving simulator is a complex mechatronic system. To simulate the load system of the joystick more effectively, this study provides a new manipulate mechanism with automatic position reset function that integrates a spring system within the joystick. The load simulation of this manipulate mechanism can be achieved by designing the nonlinear coefficient of the spring in a reasonable manner, thereby eliminating the need for complex control of motor simulation and system time delay. This greatly simplifies the complexity of the system and effectively meets the requirements of real-time and accuracy. Initially, the new manipulate mechanism is described in detail through kinematic analysis. Then, dynamic simulation is conducted in ADAMS software to simulate the motion of the operation mechanism. Considering the active–passive relationships between the manipulate mechanism and the driving simulator, a mapping is established to achieve synchronized motion. The synchronized motion is subsequently evaluated and verified in MATLAB/Simulink. The results reveal that this new manipulate mechanism has high reliability and can effectively achieve synchronized motion with the driving simulator. The new manipulate mechanism will be useful in advancing research into the design of manipulate mechanism processes.","PeriodicalId":50343,"journal":{"name":"International Journal of Advanced Robotic Systems","volume":"1 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139296212","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}
Pub Date : 2023-09-01DOI: 10.1177/17298806231199845
Qing Yang, Jili Zhou, Huijuan Meng, Dexin Gao
In the complex marine environment, target recognition is difficult, and the real-time detection has a slow speed. In this article, a target recognition method combining underwater generative adversarial network and improved YOLOv4 is proposed, which is named M-YOLOv4. Firstly, the images collected by the underwater inspection robot are enhanced using the underwater generative adversarial network algorithm to obtain the training datasets. Secondly, the YOLOv4 target detection algorithm combines the feature extraction network of MoblieNetv3 for lightweight processing, which reduces the network model size, and reduces the number of algorithm calculations and parameters. Then, change the size of the spatial pyramid pooling module pooling kernel, which can enlarge receptive field and integrate characteristics of different receptive fields. Finally, the processed datasets are transferred to the improved M-YOLOv4 algorithm for training, and the trained model is transplanted to the Jetson Nano hardware device for real-time detection. The results of experiments show that the mean average precision value of the improved M-YOLOv4 recognition is 90.77%, which is 2.02% higher than that of the unimproved one. The frame per second value of the lightweight YOLOv4 algorithm with MobileNetv3 is 27, an increase of 12 compared with YOLOv4. The improved M-YOLOv4 algorithm can perform accurate detection of marine multi-targets on embedded devices.
{"title":"Real-time marine target recognition method of underwater inspection robot based on computer vision","authors":"Qing Yang, Jili Zhou, Huijuan Meng, Dexin Gao","doi":"10.1177/17298806231199845","DOIUrl":"https://doi.org/10.1177/17298806231199845","url":null,"abstract":"In the complex marine environment, target recognition is difficult, and the real-time detection has a slow speed. In this article, a target recognition method combining underwater generative adversarial network and improved YOLOv4 is proposed, which is named M-YOLOv4. Firstly, the images collected by the underwater inspection robot are enhanced using the underwater generative adversarial network algorithm to obtain the training datasets. Secondly, the YOLOv4 target detection algorithm combines the feature extraction network of MoblieNetv3 for lightweight processing, which reduces the network model size, and reduces the number of algorithm calculations and parameters. Then, change the size of the spatial pyramid pooling module pooling kernel, which can enlarge receptive field and integrate characteristics of different receptive fields. Finally, the processed datasets are transferred to the improved M-YOLOv4 algorithm for training, and the trained model is transplanted to the Jetson Nano hardware device for real-time detection. The results of experiments show that the mean average precision value of the improved M-YOLOv4 recognition is 90.77%, which is 2.02% higher than that of the unimproved one. The frame per second value of the lightweight YOLOv4 algorithm with MobileNetv3 is 27, an increase of 12 compared with YOLOv4. The improved M-YOLOv4 algorithm can perform accurate detection of marine multi-targets on embedded devices.","PeriodicalId":50343,"journal":{"name":"International Journal of Advanced Robotic Systems","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134994881","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}
Safety plays a key role when implementing collaborative robots (cobots) in human-shared workspace scenarios. Nevertheless, the significance and understanding of safety-related aspects may significantly vary with different stakeholders’ perspectives. In particular, there is often a misconception that cobots are inherently safe with the result of significantly underestimating the need of adopting adequate safety measures and features for the deployment of collaborative robots in industrial and non-industrial frames. Accordingly, this article develops an in-depth analysis of the stakeholders and their stakes in human–robot collaboration in the manufacturing industry with particular attention to the safety aspects. The proposed approach consists of a field study, with an online questionnaire and structured interviews, directed at the main stakeholders. The field study results are presented and compared with insights from two recent explorative studies. Finally, careful analysis and discussion is provided. This research focuses on three topics: (i) the specific phases in the collaborative robot application cycle, (ii) the stakeholders that are involved in each phase, and (iii) the stakes that affect the stakeholders in general, and specifically the role of safety within these stakes. The findings show that awareness of safety issues is still jeopardized between stakeholders. In addition, key stakeholders still significantly underestimate safety-related issues when implementing cobots in new production lines. This implies the need for objective assessment tools that can systematically address and assess all safety-related aspects. This study provides industry practitioners with a broader view of how different stakeholders regard safety-related aspects in the cobot life cycle. This will enable more informed decision-making when implementing cobot solutions and potentially avoid unconsidered safety risks later on. This article also adds to the scant research on the role of each stakeholder in human–robot collaboration.
{"title":"Stakeholders’ perspectives on safety-related human–robot collaborative scenarios","authors":"Nicole Berx, Anita Brescia, Rhea Aqamarina, Elio Matteo Curcio, Liliane Pintelon, Giuseppe Carbone","doi":"10.1177/17298806231200095","DOIUrl":"https://doi.org/10.1177/17298806231200095","url":null,"abstract":"Safety plays a key role when implementing collaborative robots (cobots) in human-shared workspace scenarios. Nevertheless, the significance and understanding of safety-related aspects may significantly vary with different stakeholders’ perspectives. In particular, there is often a misconception that cobots are inherently safe with the result of significantly underestimating the need of adopting adequate safety measures and features for the deployment of collaborative robots in industrial and non-industrial frames. Accordingly, this article develops an in-depth analysis of the stakeholders and their stakes in human–robot collaboration in the manufacturing industry with particular attention to the safety aspects. The proposed approach consists of a field study, with an online questionnaire and structured interviews, directed at the main stakeholders. The field study results are presented and compared with insights from two recent explorative studies. Finally, careful analysis and discussion is provided. This research focuses on three topics: (i) the specific phases in the collaborative robot application cycle, (ii) the stakeholders that are involved in each phase, and (iii) the stakes that affect the stakeholders in general, and specifically the role of safety within these stakes. The findings show that awareness of safety issues is still jeopardized between stakeholders. In addition, key stakeholders still significantly underestimate safety-related issues when implementing cobots in new production lines. This implies the need for objective assessment tools that can systematically address and assess all safety-related aspects. This study provides industry practitioners with a broader view of how different stakeholders regard safety-related aspects in the cobot life cycle. This will enable more informed decision-making when implementing cobot solutions and potentially avoid unconsidered safety risks later on. This article also adds to the scant research on the role of each stakeholder in human–robot collaboration.","PeriodicalId":50343,"journal":{"name":"International Journal of Advanced Robotic Systems","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134994909","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}
Pub Date : 2023-09-01DOI: 10.1177/17298806231198936
Wei Wang, Zequan Xu, Qinchuan Li, Jin Wang, Ran Huo, Guodong Lu
Coordinated manipulators can construct a series system, such that all the position error of the end-effector is required to remain within the permissible limit. This article proposed a new method to handle the problem of reliability analysis involving in multiple failure modes. The extreme value of the position error is introduced to construct a surrogate model to replace the original failure event, the moment with fraction order instead of the traditional integer is applied to derive the best-fit distribution of the extreme value based on the maximum entropy principle. The innovations mainly include: (1) the high efficient dimension reduction via the surrogate model constructed with the extreme value and (2) a better probability density function is derived through the fractional moment. A series system consists of three manipulators is used as an example to demonstrate the efficiency and accuracy of the proposed method.
{"title":"The motion reliability analysis of a series system with multiple coordinated manipulators","authors":"Wei Wang, Zequan Xu, Qinchuan Li, Jin Wang, Ran Huo, Guodong Lu","doi":"10.1177/17298806231198936","DOIUrl":"https://doi.org/10.1177/17298806231198936","url":null,"abstract":"Coordinated manipulators can construct a series system, such that all the position error of the end-effector is required to remain within the permissible limit. This article proposed a new method to handle the problem of reliability analysis involving in multiple failure modes. The extreme value of the position error is introduced to construct a surrogate model to replace the original failure event, the moment with fraction order instead of the traditional integer is applied to derive the best-fit distribution of the extreme value based on the maximum entropy principle. The innovations mainly include: (1) the high efficient dimension reduction via the surrogate model constructed with the extreme value and (2) a better probability density function is derived through the fractional moment. A series system consists of three manipulators is used as an example to demonstrate the efficiency and accuracy of the proposed method.","PeriodicalId":50343,"journal":{"name":"International Journal of Advanced Robotic Systems","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135347567","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}
Pub Date : 2023-09-01DOI: 10.1177/17298806231206940
Qin Zhang, Zhenyu Liu, Hui Chai, Yueyang Li
When two manipulators cooperate to clamp a rigid object, a closed chain with both ends fixed is formed. The singularity of a single manipulator causes the closed chain to be at a singularity, which results in uncertainty in the velocity mapping between the terminal and joint space. This study proposes a closed-chain singularity processing method for dual-arm collaboration, adopting the Jacobian pseudoinverse method based on damped least squares to obtain an approximate solution. During the solution process, the adaptive damping factor is improved by cubic polynomials, and the optimal damping factor is determined by quadratic sequence programming. Furthermore, this study analyzes the kinematic constraints of the closed-chain system and constructs a closed-chain Jacobian to judge whether the system is in a singular region. Finally, the effectiveness of the proposed method is verified through simulations.
{"title":"Singularity avoidance method for dual-arm closed-chain system based on damped least squares","authors":"Qin Zhang, Zhenyu Liu, Hui Chai, Yueyang Li","doi":"10.1177/17298806231206940","DOIUrl":"https://doi.org/10.1177/17298806231206940","url":null,"abstract":"When two manipulators cooperate to clamp a rigid object, a closed chain with both ends fixed is formed. The singularity of a single manipulator causes the closed chain to be at a singularity, which results in uncertainty in the velocity mapping between the terminal and joint space. This study proposes a closed-chain singularity processing method for dual-arm collaboration, adopting the Jacobian pseudoinverse method based on damped least squares to obtain an approximate solution. During the solution process, the adaptive damping factor is improved by cubic polynomials, and the optimal damping factor is determined by quadratic sequence programming. Furthermore, this study analyzes the kinematic constraints of the closed-chain system and constructs a closed-chain Jacobian to judge whether the system is in a singular region. Finally, the effectiveness of the proposed method is verified through simulations.","PeriodicalId":50343,"journal":{"name":"International Journal of Advanced Robotic Systems","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135735387","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}
Pub Date : 2023-07-01DOI: 10.1177/17298806231191938
Tianjiao Zheng, Jingsong Gao, Sikai Zhao, Mingzhu Lai, Yang Gao, Jie Zhao, Yanhe Zhu
Lower-limb exoskeletons have attracted considerable interest because they can provide impaired individuals with the ability to walk upright. Trajectory generation of walking gait is a crucial issue for lower-limb exoskeletons that has not yet been satisfactorily solved. The purpose of this article is to study a stable gait generation method considering the subjective walking intention. Inspired by the motion synergy between crutches and lower limbs, a stable gait generation method for flat-ground walking was proposed for a lower-limb exoskeleton. The motion synergy in the sagittal plane between the crutch-pitch-angle and step length was validated using theoretical and experimental methods. The synergistic relationship between the maximum crutch-pitch-angle and step-length coefficient was established and optimized. Based on the synergistic relationship, the gait trajectory of the exoskeleton with variable step length can be instinctively generated with a crutch swing. The gait stability of the human-exoskeleton system was modeled and analyzed. Consecutive walking experiments were conducted on flat ground in which a compact lower-limb exoskeleton and pair of instrumented crutches were employed. The results demonstrate that gait based on the synergistic relationship is effective and stable, thereby verifying the feasibility of this human-in-the-loop gait generation method.
{"title":"Stable gait generation method for lower-limb exoskeleton based on instrumented crutches","authors":"Tianjiao Zheng, Jingsong Gao, Sikai Zhao, Mingzhu Lai, Yang Gao, Jie Zhao, Yanhe Zhu","doi":"10.1177/17298806231191938","DOIUrl":"https://doi.org/10.1177/17298806231191938","url":null,"abstract":"Lower-limb exoskeletons have attracted considerable interest because they can provide impaired individuals with the ability to walk upright. Trajectory generation of walking gait is a crucial issue for lower-limb exoskeletons that has not yet been satisfactorily solved. The purpose of this article is to study a stable gait generation method considering the subjective walking intention. Inspired by the motion synergy between crutches and lower limbs, a stable gait generation method for flat-ground walking was proposed for a lower-limb exoskeleton. The motion synergy in the sagittal plane between the crutch-pitch-angle and step length was validated using theoretical and experimental methods. The synergistic relationship between the maximum crutch-pitch-angle and step-length coefficient was established and optimized. Based on the synergistic relationship, the gait trajectory of the exoskeleton with variable step length can be instinctively generated with a crutch swing. The gait stability of the human-exoskeleton system was modeled and analyzed. Consecutive walking experiments were conducted on flat ground in which a compact lower-limb exoskeleton and pair of instrumented crutches were employed. The results demonstrate that gait based on the synergistic relationship is effective and stable, thereby verifying the feasibility of this human-in-the-loop gait generation method.","PeriodicalId":50343,"journal":{"name":"International Journal of Advanced Robotic Systems","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43975614","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：