A parallel manipulator is naturally associated with a set of constraint functions defined by its closure constraints. The differential forms arising from these constraint functions completely characterize the geometric properties of the manipulator. In this paper, using the language of differential forms, we provide a thorough geometric study on the various types of singularities of a parallel manipulator, their relations with the kinematic parameters and the configuration spaces of the manipulator, and the role redundant actuation plays in reshaping the singularities and improving the performance of the manipulator. First, we analyze configuration space singularities by constructing a Morse function on some appropriately defined spaces. By varying key parameters of the manipulator, we obtain homotopic classes of the configuration spaces. This allows us to gain insight on configuration space singularities and understand how to choose design parameters for the manipulator. Second, we define parametrization singularities which include actuator and end-effector singularities (or other equivalent definitions) as their special cases. This definition naturally contains the closure constraints in addition to the coordinates of the actuators and the end-effector and can be used to search a complete set of actuator or end-effector singularities including some singularities that may be missed by the usual kinematics methods. We give an intrinsic classification of parametrization singularities and define their topological orders. While a nondegenerate singularity poses no problems in general, a degenerate singularity can sometimes be a source of danger and should be avoided if possible.
{"title":"Singularities of parallel manipulators: a geometric treatment","authors":"Guanfeng Liu, Y. Lou, Zexiang Li","doi":"10.1109/TRA.2003.814507","DOIUrl":"https://doi.org/10.1109/TRA.2003.814507","url":null,"abstract":"A parallel manipulator is naturally associated with a set of constraint functions defined by its closure constraints. The differential forms arising from these constraint functions completely characterize the geometric properties of the manipulator. In this paper, using the language of differential forms, we provide a thorough geometric study on the various types of singularities of a parallel manipulator, their relations with the kinematic parameters and the configuration spaces of the manipulator, and the role redundant actuation plays in reshaping the singularities and improving the performance of the manipulator. First, we analyze configuration space singularities by constructing a Morse function on some appropriately defined spaces. By varying key parameters of the manipulator, we obtain homotopic classes of the configuration spaces. This allows us to gain insight on configuration space singularities and understand how to choose design parameters for the manipulator. Second, we define parametrization singularities which include actuator and end-effector singularities (or other equivalent definitions) as their special cases. This definition naturally contains the closure constraints in addition to the coordinates of the actuators and the end-effector and can be used to search a complete set of actuator or end-effector singularities including some singularities that may be missed by the usual kinematics methods. We give an intrinsic classification of parametrization singularities and define their topological orders. While a nondegenerate singularity poses no problems in general, a degenerate singularity can sometimes be a source of danger and should be avoided if possible.","PeriodicalId":161449,"journal":{"name":"IEEE Trans. Robotics Autom.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128291679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents a methodology for optimal allocation of sensors in a multistation assembly process for the purpose of diagnosing in a timely manner variation sources that are responsible for product quality defects. A sensor system distributed in such a way can help manufacturers improve product quality while, at the same time, reducing process downtime. Traditional approaches in sensor optimization fall into two categories: multistation sensor allocation for the purpose of product inspection (rather than diagnosis); and allocation of sensors for the purpose of variation diagnosis but at a single measurement station. In our approach, sensing information from different measurement stations is integrated into a state-space model and the effectiveness of a distributed sensor system is quantified by a diagnosability index. This index is further studied in terms of variation transmissibility between stations as well as variation detectability at individual stations. Based on an understanding of the mechanism of variation propagation, we develop a backward-propagation strategy to determine the locations of measurement stations and the minimum number of sensors needed to achieve full diagnosability. An assembly example illustrates the methodology.
{"title":"Optimal sensor distribution for variation diagnosis in multistation assembly processes","authors":"Yu Ding, Pansoo Kim, D. Ceglarek, Jionghua Jin","doi":"10.1109/TRA.2003.814516","DOIUrl":"https://doi.org/10.1109/TRA.2003.814516","url":null,"abstract":"This paper presents a methodology for optimal allocation of sensors in a multistation assembly process for the purpose of diagnosing in a timely manner variation sources that are responsible for product quality defects. A sensor system distributed in such a way can help manufacturers improve product quality while, at the same time, reducing process downtime. Traditional approaches in sensor optimization fall into two categories: multistation sensor allocation for the purpose of product inspection (rather than diagnosis); and allocation of sensors for the purpose of variation diagnosis but at a single measurement station. In our approach, sensing information from different measurement stations is integrated into a state-space model and the effectiveness of a distributed sensor system is quantified by a diagnosability index. This index is further studied in terms of variation transmissibility between stations as well as variation detectability at individual stations. Based on an understanding of the mechanism of variation propagation, we develop a backward-propagation strategy to determine the locations of measurement stations and the minimum number of sensors needed to achieve full diagnosability. An assembly example illustrates the methodology.","PeriodicalId":161449,"journal":{"name":"IEEE Trans. Robotics Autom.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134474631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The field of evolutionary robotics has demonstrated the ability to automatically design the morphology and controller of simple physical robots through synthetic evolutionary processes. However, it is not clear if variation-based search processes can attain the complexity of design necessary for practical engineering of robots. Here, we demonstrate an automatic design system that produces complex robots by exploiting the principles of regularity, modularity, hierarchy, and reuse. These techniques are already established principles of scaling in engineering design and have been observed in nature, but have not been broadly used in artificial evolution. We gain these advantages through the use of a generative representation, which combines a programmatic representation with an algorithmic process that compiles the representation into a detailed construction plan. This approach is shown to have two benefits: it can reuse components in regular and hierarchical ways, providing a systematic way to create more complex modules from simpler ones; and the evolved representations can capture intrinsic properties of the design space, so that variations in the representations move through the design space more effectively than equivalent-sized changes in a nongenerative representation. Using this system, we demonstrate for the first time the evolution and construction of modular, three-dimensional, physically locomoting robots, comprising many more components than previous work on body-brain evolution.
{"title":"Generative representations for the automated design of modular physical robots","authors":"G. Hornby, Hod Lipson, J. Pollack","doi":"10.1109/TRA.2003.814502","DOIUrl":"https://doi.org/10.1109/TRA.2003.814502","url":null,"abstract":"The field of evolutionary robotics has demonstrated the ability to automatically design the morphology and controller of simple physical robots through synthetic evolutionary processes. However, it is not clear if variation-based search processes can attain the complexity of design necessary for practical engineering of robots. Here, we demonstrate an automatic design system that produces complex robots by exploiting the principles of regularity, modularity, hierarchy, and reuse. These techniques are already established principles of scaling in engineering design and have been observed in nature, but have not been broadly used in artificial evolution. We gain these advantages through the use of a generative representation, which combines a programmatic representation with an algorithmic process that compiles the representation into a detailed construction plan. This approach is shown to have two benefits: it can reuse components in regular and hierarchical ways, providing a systematic way to create more complex modules from simpler ones; and the evolved representations can capture intrinsic properties of the design space, so that variations in the representations move through the design space more effectively than equivalent-sized changes in a nongenerative representation. Using this system, we demonstrate for the first time the evolution and construction of modular, three-dimensional, physically locomoting robots, comprising many more components than previous work on body-brain evolution.","PeriodicalId":161449,"journal":{"name":"IEEE Trans. Robotics Autom.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126942488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The snakeboard is shown to possess two decoupling vector fields, and to be kinematically controllable. Accordingly, the problem of steering the snakeboard from a given configuration at rest to a desired configuration at rest is posed as a constrained static nonlinear inversion problem. An explicit algorithmic solution to the problem is provided, and its limitations are discussed. An ad hoc solution to the nonlinear inversion problem is also exhibited.
{"title":"Kinematic controllability and motion planning for the snakeboard","authors":"F. Bullo, A. D. Lewis","doi":"10.1109/TRA.2003.810236","DOIUrl":"https://doi.org/10.1109/TRA.2003.810236","url":null,"abstract":"The snakeboard is shown to possess two decoupling vector fields, and to be kinematically controllable. Accordingly, the problem of steering the snakeboard from a given configuration at rest to a desired configuration at rest is posed as a constrained static nonlinear inversion problem. An explicit algorithmic solution to the problem is provided, and its limitations are discussed. An ad hoc solution to the nonlinear inversion problem is also exhibited.","PeriodicalId":161449,"journal":{"name":"IEEE Trans. Robotics Autom.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127078217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents a path-planning algorithm for an articulated planar robot with a static obstacle. The algorithm selects a robot part, finds a path to its goal configuration by systematic configuration space search, drags the entire robot along the path using compliant motion, and repeats the cycle until every robot part reaches its goal. The planner is tested on 11 000 random problems, which span dozens of robot/obstacle geometries with up to 43 moving parts and with narrow channels. It solves every problem in seconds, whereas randomized algorithms appear to fail on all of them.
{"title":"Path planning for planar articulated robots using configuration spaces and compliant motion","authors":"E. Sacks","doi":"10.1109/TRA.2003.810237","DOIUrl":"https://doi.org/10.1109/TRA.2003.810237","url":null,"abstract":"This paper presents a path-planning algorithm for an articulated planar robot with a static obstacle. The algorithm selects a robot part, finds a path to its goal configuration by systematic configuration space search, drags the entire robot along the path using compliant motion, and repeats the cycle until every robot part reaches its goal. The planner is tested on 11 000 random problems, which span dozens of robot/obstacle geometries with up to 43 moving parts and with narrow channels. It solves every problem in seconds, whereas randomized algorithms appear to fail on all of them.","PeriodicalId":161449,"journal":{"name":"IEEE Trans. Robotics Autom.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132279301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Proposes an application of the Stewart-Gough parallel platform as a climbing robot and its kinematics control to climb through long structures describing unknown spatial trajectories, such as palm trunks, tubes, etc. First, the description and design of the climbing parallel robot is presented. Second, the inverse and forward kinematics analysis of a mobile six-degrees-of-freedom parallel robot is described, based on spatial constraint formulation. Finally, the gait pattern and the climbing strategy of the parallel robot is described. The information from this research is being used in an actual climbing parallel robot design at Miguel Hernandez University of Elche (Alicante), Spain.
提出了Stewart-Gough并联平台在攀爬机器人中的应用及其运动学控制,用于攀爬具有未知空间轨迹的长结构,如棕榈树干、管子等。首先,对攀爬并联机器人进行了描述和设计。其次,基于空间约束公式对移动六自由度并联机器人进行了运动学逆解和正解分析。最后,描述了并联机器人的步态模式和攀爬策略。西班牙埃尔切(阿利坎特)米格尔·埃尔南德斯大学(Miguel Hernandez University of Elche)正在将这项研究的信息用于实际的攀爬并联机器人设计中。
{"title":"Motion planning of a climbing parallel robot","authors":"M. A. Kroeger, R. Saltarén, R. Aracil, Ó. Reinoso","doi":"10.1109/TRA.2003.810238","DOIUrl":"https://doi.org/10.1109/TRA.2003.810238","url":null,"abstract":"Proposes an application of the Stewart-Gough parallel platform as a climbing robot and its kinematics control to climb through long structures describing unknown spatial trajectories, such as palm trunks, tubes, etc. First, the description and design of the climbing parallel robot is presented. Second, the inverse and forward kinematics analysis of a mobile six-degrees-of-freedom parallel robot is described, based on spatial constraint formulation. Finally, the gait pattern and the climbing strategy of the parallel robot is described. The information from this research is being used in an actual climbing parallel robot design at Miguel Hernandez University of Elche (Alicante), Spain.","PeriodicalId":161449,"journal":{"name":"IEEE Trans. Robotics Autom.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115492262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Planning of a dextrous manipulation task for a multifingered hand requires the feasibility of all the grasps involved throughout the manipulation process. In this paper, we address the problem of determining whether a desired grasp of a polyhedral object is kinematically feasible. In our study, we define a grasp in terms of a system of contact pairs between the topological features of the hand and the object, and formulate the grasp feasibility analysis as a set of equality and inequality constraints in the variables of the hand and object configurations. The feasibility of a grasp then becomes equivalent to the simultaneous satisfaction of all the constraints. This allows us to cast the feasibility analysis conveniently as a constrained nonlinear optimization problem and solve it numerically with commercially available software. The effectiveness of our approach is illustrated with an example of grasping a cuboid using a three-fingered robotic hand.
{"title":"Kinematic feasibility analysis of 3-D multifingered grasps","authors":"Y. Guan, Hong Zhang","doi":"10.1109/TRA.2003.810235","DOIUrl":"https://doi.org/10.1109/TRA.2003.810235","url":null,"abstract":"Planning of a dextrous manipulation task for a multifingered hand requires the feasibility of all the grasps involved throughout the manipulation process. In this paper, we address the problem of determining whether a desired grasp of a polyhedral object is kinematically feasible. In our study, we define a grasp in terms of a system of contact pairs between the topological features of the hand and the object, and formulate the grasp feasibility analysis as a set of equality and inequality constraints in the variables of the hand and object configurations. The feasibility of a grasp then becomes equivalent to the simultaneous satisfaction of all the constraints. This allows us to cast the feasibility analysis conveniently as a constrained nonlinear optimization problem and solve it numerically with commercially available software. The effectiveness of our approach is illustrated with an example of grasping a cuboid using a three-fingered robotic hand.","PeriodicalId":161449,"journal":{"name":"IEEE Trans. Robotics Autom.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117278694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To be able to recognize an environment, a robot should have as many sensors as possible. When we use sensors, we must consider the characteristics of the sensors, such as range, processing time, error, and so on. In this paper, we focus on the ultrasonic wave sensor that is today the most common sensor employed on indoor mobile robotic systems, and we propose a new technique for estimating the smoothed value and the differential value of the distances measured by the ultrasonic wave sensor. In proposing this system, we take the characteristics of the sensors mentioned above into consideration. In spite of the many methods proposed, it is still very difficult to eliminate the noise of sonar completely. Therefore, we smooth the distance value by assuming the continuity of the signal obtained by the sonar, and taking advantage of this continuity, we compose a robust estimator. The estimator is based on the sliding mode system.
{"title":"Research on estimating smoothed value and differential value by using sliding mode system","authors":"T. Emaru, T. Tsuchiya","doi":"10.1109/TRA.2003.810243","DOIUrl":"https://doi.org/10.1109/TRA.2003.810243","url":null,"abstract":"To be able to recognize an environment, a robot should have as many sensors as possible. When we use sensors, we must consider the characteristics of the sensors, such as range, processing time, error, and so on. In this paper, we focus on the ultrasonic wave sensor that is today the most common sensor employed on indoor mobile robotic systems, and we propose a new technique for estimating the smoothed value and the differential value of the distances measured by the ultrasonic wave sensor. In proposing this system, we take the characteristics of the sensors mentioned above into consideration. In spite of the many methods proposed, it is still very difficult to eliminate the noise of sonar completely. Therefore, we smooth the distance value by assuming the continuity of the signal obtained by the sonar, and taking advantage of this continuity, we compose a robust estimator. The estimator is based on the sliding mode system.","PeriodicalId":161449,"journal":{"name":"IEEE Trans. Robotics Autom.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122557022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents a humanoid robotic shoulder complex and the kinematics of humanoid humeral pointing as performed by this complex. The humanoid shoulder complex is composed of two subsystems, a parallel mechanism which serves as the innermost shoulder girdle and a serial mechanism which serves as the outermost spherical glenohumeral joint. These two subsystems are separated by an offset distance and a twist angle. The subsystems operate cooperatively as an offset double pointing system. Humanoid humeral pointing is defined as a configuration in which the displacement of the shoulder girdle and the humerus are coplanar, and in which a ratio between an inclination angle in each subsystem achieves a constant value consistent with human humeral pointing. One redundant degree of freedom remains in the humanoid shoulder girdle, and it can be used to optimize system configuration and operating criteria, such as avoiding the singular cones of the humanoid glenohumeral joint.
{"title":"A humanoid shoulder complex and the humeral pointing kinematics","authors":"J. Lenarcic, M. Stanisic","doi":"10.1109/TRA.2003.810578","DOIUrl":"https://doi.org/10.1109/TRA.2003.810578","url":null,"abstract":"This paper presents a humanoid robotic shoulder complex and the kinematics of humanoid humeral pointing as performed by this complex. The humanoid shoulder complex is composed of two subsystems, a parallel mechanism which serves as the innermost shoulder girdle and a serial mechanism which serves as the outermost spherical glenohumeral joint. These two subsystems are separated by an offset distance and a twist angle. The subsystems operate cooperatively as an offset double pointing system. Humanoid humeral pointing is defined as a configuration in which the displacement of the shoulder girdle and the humerus are coplanar, and in which a ratio between an inclination angle in each subsystem achieves a constant value consistent with human humeral pointing. One redundant degree of freedom remains in the humanoid shoulder girdle, and it can be used to optimize system configuration and operating criteria, such as avoiding the singular cones of the humanoid glenohumeral joint.","PeriodicalId":161449,"journal":{"name":"IEEE Trans. Robotics Autom.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123887790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Proposes a flexible assembly system, where autonomous manufacturing devices and production management agents communicate with one another to accomplish production tasks. This architecture allows the system to arrange manufacturing devices independently of the type of products assembled and to assemble multiple products in parallel and asynchronous progress. This system also supports plug and produce, a system function that realizes easy reconfiguration. Thus, the system can return quick responses to breakdowns and changes in production quantities. This paper also presents an index for the general evaluation of reconfigurable manufacturing systems. With this index and the plug-and-produce function, the system can be reconfigured appropriately to adapt to changes in the manufacturing environments.
{"title":"A holonic architecture for easy reconfiguration of robotic assembly systems","authors":"M. Sugi, Y. Maeda, Y. Aiyama, T. Harada, T. Arai","doi":"10.1109/TRA.2003.810241","DOIUrl":"https://doi.org/10.1109/TRA.2003.810241","url":null,"abstract":"Proposes a flexible assembly system, where autonomous manufacturing devices and production management agents communicate with one another to accomplish production tasks. This architecture allows the system to arrange manufacturing devices independently of the type of products assembled and to assemble multiple products in parallel and asynchronous progress. This system also supports plug and produce, a system function that realizes easy reconfiguration. Thus, the system can return quick responses to breakdowns and changes in production quantities. This paper also presents an index for the general evaluation of reconfigurable manufacturing systems. With this index and the plug-and-produce function, the system can be reconfigured appropriately to adapt to changes in the manufacturing environments.","PeriodicalId":161449,"journal":{"name":"IEEE Trans. Robotics Autom.","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2003-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129542986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}