Peng Yan, Hailin Huang, Sen Wang, Bing Li, Zhifeng Zhang
Pipeline inspection in unknown environments is challenging for robots, and various In-pipe crawling robots have been developed in recent years to perform pipeline inspection. Most of these robots comprise multiple segments and require multiple actuators to realize the pipeline locomotion, resulting in complicated system composition and large energy consumption. In this paper, inspired by the crawling principles of earthworm locomotion, we propose a single-actuated camshaft robot that can realize multiple sequential motions for pipeline crawling. The proposed singled-actuated camshaft robot contains one actuator and three segments: head anchoring, body elongation, and rear anchoring segment. The multiple sequential motions of these three segments are realized based on the cam mechanisms. Umbrella-shaped elastic rubbers are longitudinally arranged around the head and rear anchoring segments. Each segment contains a cam bracket. The camshaft's rotatory motion pushes the cam brackets to generate the axial translational motion, resulting in the umbrella-shaped elastic rubbers being expanded or contracted. The proposed camshaft robot's expansion and contraction motion are sequentially realized by the phase deviation of the camshafts. First, the structures of the proposed robot are designed. Then, the cam curves are modeled, the expansion/contraction ratio of the rear/head anchoring segment is calculated, the phase deviation of the camshafts is determined, and multiple sequential motions of the proposed robot are simulated. Finally, we fabricate the proposed camshaft robot and carry out crawling experiments in pipelines with different shapes and diameters.
{"title":"Single-actuated camshaft robot with multiple sequential motions","authors":"Peng Yan, Hailin Huang, Sen Wang, Bing Li, Zhifeng Zhang","doi":"10.1115/1.4062987","DOIUrl":"https://doi.org/10.1115/1.4062987","url":null,"abstract":"\u0000 Pipeline inspection in unknown environments is challenging for robots, and various In-pipe crawling robots have been developed in recent years to perform pipeline inspection. Most of these robots comprise multiple segments and require multiple actuators to realize the pipeline locomotion, resulting in complicated system composition and large energy consumption. In this paper, inspired by the crawling principles of earthworm locomotion, we propose a single-actuated camshaft robot that can realize multiple sequential motions for pipeline crawling. The proposed singled-actuated camshaft robot contains one actuator and three segments: head anchoring, body elongation, and rear anchoring segment. The multiple sequential motions of these three segments are realized based on the cam mechanisms. Umbrella-shaped elastic rubbers are longitudinally arranged around the head and rear anchoring segments. Each segment contains a cam bracket. The camshaft's rotatory motion pushes the cam brackets to generate the axial translational motion, resulting in the umbrella-shaped elastic rubbers being expanded or contracted. The proposed camshaft robot's expansion and contraction motion are sequentially realized by the phase deviation of the camshafts. First, the structures of the proposed robot are designed. Then, the cam curves are modeled, the expansion/contraction ratio of the rear/head anchoring segment is calculated, the phase deviation of the camshafts is determined, and multiple sequential motions of the proposed robot are simulated. Finally, we fabricate the proposed camshaft robot and carry out crawling experiments in pipelines with different shapes and diameters.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43176809","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}
Trajectory learning is an important part of robot skill learning, and a trajectory learning method based on improved Dynamic Movement Primitives (DMPs) is proposed to improve trajectory reproduction accuracy. In this method, the truncation processing is used to improve the Gaussian kernel function of DMPs to eliminate the impact of tail exponential decay on fitted target forcing term, and the optimization on the number of shape parameters is used to make the model better approximate the local gradient of the target forcing term. The principle of trajectory accuracy improvement is described in detail. The trajectory reproduction simulation is performed, which verifies the feasibility of the proposed method. An experimental setup for robot skill trajectory learning is constructed and the relevant comparison experiments are performed, which verifies the effectiveness of the proposed method in improving trajectory learning accuracy.
{"title":"High Precision Trajectory Learning Method based Improved Dynamic Movement Primitives for Robot Skill Learning","authors":"Bin Zhai, Enzheng Zhang, Bingchen Li, Xiujun Fang","doi":"10.1115/1.4062985","DOIUrl":"https://doi.org/10.1115/1.4062985","url":null,"abstract":"\u0000 Trajectory learning is an important part of robot skill learning, and a trajectory learning method based on improved Dynamic Movement Primitives (DMPs) is proposed to improve trajectory reproduction accuracy. In this method, the truncation processing is used to improve the Gaussian kernel function of DMPs to eliminate the impact of tail exponential decay on fitted target forcing term, and the optimization on the number of shape parameters is used to make the model better approximate the local gradient of the target forcing term. The principle of trajectory accuracy improvement is described in detail. The trajectory reproduction simulation is performed, which verifies the feasibility of the proposed method. An experimental setup for robot skill trajectory learning is constructed and the relevant comparison experiments are performed, which verifies the effectiveness of the proposed method in improving trajectory learning accuracy.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44984302","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}
The authors propose a systematic formulation of the dynamics of the 6-P-RR-R-RR parallel-kinematics machine (PKM) with offset RR-joints. The kinematics of the same system is reported in an accompanying paper. Based on the kinematics model developed in the former, the dynamics model of the limb-chain is derived using the Newton-Euler equations. Then, the constraint wrenches in the governing equations of the limb-chain are eliminated with the aid of the natural orthogonal complement (NOC). This is the twist-shaping matrix, which maps the joint-rate array of the limb-chain into the twist array of the PKM. Furthermore, the dynamics model of the whole PKM with offset joints is formulated. Moreover, the actuator forces are obtained. Finally, upon validation via simulation, the dynamics model is proven to be both precise and effective.
{"title":"Dynamics of a Parallel-kinematics Machine with Six Pairs of Offset Joints","authors":"Ha-si-ao-qi-er Han, J. Angeles","doi":"10.1115/1.4062984","DOIUrl":"https://doi.org/10.1115/1.4062984","url":null,"abstract":"\u0000 The authors propose a systematic formulation of the dynamics of the 6-P-RR-R-RR parallel-kinematics machine (PKM) with offset RR-joints. The kinematics of the same system is reported in an accompanying paper. Based on the kinematics model developed in the former, the dynamics model of the limb-chain is derived using the Newton-Euler equations. Then, the constraint wrenches in the governing equations of the limb-chain are eliminated with the aid of the natural orthogonal complement (NOC). This is the twist-shaping matrix, which maps the joint-rate array of the limb-chain into the twist array of the PKM. Furthermore, the dynamics model of the whole PKM with offset joints is formulated. Moreover, the actuator forces are obtained. Finally, upon validation via simulation, the dynamics model is proven to be both precise and effective.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49161016","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}
Bistable soft robots are gaining momentum for their fast speed. This study presents a novel asymmetric mechanically-prestressed, pneumatically-driven, bistable laminated soft actuator. Its two orthogonal stable shapes are created by prestretching two orthogonal elastomer matrix composites (EMCs) before bonding them to a thin core layer. Two fluidic layers with fluid channels are bonded on either side of the core layer to actuate and trigger the snap-through process of the actuator. An analytical model is proposed as follows: the actuator net energy is calculated based on polynomials with unknown coefficients, and the stable shapes of the actuator are computed as a result of pneumatic pressure and external loads with the Rayleigh-Ritz method. Bistable actuators are fabricated with different prestrains, and motion capture and tensile loading experiments are conducted for model validation. A gripper is fabricated with two bistable actuators and demonstrated to grasp a variety of objects. Sensitivity studies are performed to identify the actuator response as a function of a variety of design parameters.
{"title":"Mechanically-prestressed pneumatically-driven bistable soft actuators","authors":"Yitong Zhou, Zefeng Xu","doi":"10.1115/1.4062949","DOIUrl":"https://doi.org/10.1115/1.4062949","url":null,"abstract":"Bistable soft robots are gaining momentum for their fast speed. This study presents a novel asymmetric mechanically-prestressed, pneumatically-driven, bistable laminated soft actuator. Its two orthogonal stable shapes are created by prestretching two orthogonal elastomer matrix composites (EMCs) before bonding them to a thin core layer. Two fluidic layers with fluid channels are bonded on either side of the core layer to actuate and trigger the snap-through process of the actuator. An analytical model is proposed as follows: the actuator net energy is calculated based on polynomials with unknown coefficients, and the stable shapes of the actuator are computed as a result of pneumatic pressure and external loads with the Rayleigh-Ritz method. Bistable actuators are fabricated with different prestrains, and motion capture and tensile loading experiments are conducted for model validation. A gripper is fabricated with two bistable actuators and demonstrated to grasp a variety of objects. Sensitivity studies are performed to identify the actuator response as a function of a variety of design parameters.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43375263","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}
The introduction of intrinsic compliance in the design of robots allows to reduce the inherent risk for humans working in the vicinity of a robotic cell. Indeed, it permits to decouple the dynamic effects of the links' inertia from those of the rotors' inertia, thus reducing the maximum impact force. However, robot designers are lacking modeling tools to help simulate numerous collision scenarios, analyze the behaviour of a compliant robot and optimize its design. In this article, we introduce a method to reduce the model of a multi-link compliant robot in a simple translationnal mass-spring-mass system. Simulation results show that this reduced model allows to accurately predict the maximal impact force in the case of a collision with a constrained human body part, and thus estimate the severity of such collision. Multiple impact scenarios are conducted on two case-studies, a planar serial elastic robot and the R-Min robot, an underactuated parallel planar robot, designed for collaboration.
{"title":"A Reduced Mass-Spring-Mass Model of Compliant Robots Dedicated to the Evaluation of Impact Forces","authors":"Guillaume Jeanneau, Vincent Bégoc, S. Briot","doi":"10.1115/1.4062946","DOIUrl":"https://doi.org/10.1115/1.4062946","url":null,"abstract":"\u0000 The introduction of intrinsic compliance in the design of robots allows to reduce the inherent risk for humans working in the vicinity of a robotic cell. Indeed, it permits to decouple the dynamic effects of the links' inertia from those of the rotors' inertia, thus reducing the maximum impact force. However, robot designers are lacking modeling tools to help simulate numerous collision scenarios, analyze the behaviour of a compliant robot and optimize its design. In this article, we introduce a method to reduce the model of a multi-link compliant robot in a simple translationnal mass-spring-mass system. Simulation results show that this reduced model allows to accurately predict the maximal impact force in the case of a collision with a constrained human body part, and thus estimate the severity of such collision. Multiple impact scenarios are conducted on two case-studies, a planar serial elastic robot and the R-Min robot, an underactuated parallel planar robot, designed for collaboration.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47293054","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}
Robots are playing an important role in precision manufacturing and automated inspection, which places higher demands on the positioning accuracy. The Delta robot is the most widely used parallel robot with high speed and small cumulative error. In this way, improving the positioning accuracy of the Delta robot can expand its application scenarios. According to the parameter mapping relationship, the position error can be divided into geometric error and non-geometric error. Considering the influence of the orientation errors on the actual position of the robot end, an error model to recognize the geometric error is established, and the parameter identification is performed based on an iterative approach. For the non-geometric error, the 3D annular sector grid division method and the interpolation rule are established based on the error similarity. And then, a new error compensation method for Delta robots is proposed by combining geometric error modeling with spatial interpolating. After compensation, the positioning accuracy of the Delta robot is improved significantly. The maximum absolute positioning error of the robot is reduced by 86.08% from 2.084 mm to 0.290 mm, the average absolute positioning error of the robot is reduced by 81.77% from 0.790 mm to 0.144 mm, and the error trend in the workspace is eliminated, so as to enable the expansion of Delta robot applications.
{"title":"A new error compensation method for Delta robots combining geometric error modeling with spatial interpolating","authors":"Jianwei Ma, Yabin Shen, Shumei Zhang, Hui-Teng Yan, Zhenyuan Jia","doi":"10.1115/1.4062947","DOIUrl":"https://doi.org/10.1115/1.4062947","url":null,"abstract":"\u0000 Robots are playing an important role in precision manufacturing and automated inspection, which places higher demands on the positioning accuracy. The Delta robot is the most widely used parallel robot with high speed and small cumulative error. In this way, improving the positioning accuracy of the Delta robot can expand its application scenarios. According to the parameter mapping relationship, the position error can be divided into geometric error and non-geometric error. Considering the influence of the orientation errors on the actual position of the robot end, an error model to recognize the geometric error is established, and the parameter identification is performed based on an iterative approach. For the non-geometric error, the 3D annular sector grid division method and the interpolation rule are established based on the error similarity. And then, a new error compensation method for Delta robots is proposed by combining geometric error modeling with spatial interpolating. After compensation, the positioning accuracy of the Delta robot is improved significantly. The maximum absolute positioning error of the robot is reduced by 86.08% from 2.084 mm to 0.290 mm, the average absolute positioning error of the robot is reduced by 81.77% from 0.790 mm to 0.144 mm, and the error trend in the workspace is eliminated, so as to enable the expansion of Delta robot applications.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48869549","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}
This paper proposes a novel kinematic calibration method to address the ill-conditioned identification matrix problem and enhance the accuracy of Parallel Manipulators (PMs). The kinematic calibration method applies the Truncated Total Least Squares (T-TLS) regularization method to the inverse kinematic calibration of PMs and doesn't have the unit inconsistency issue and configuration selection issue. The performance of the T-TLS method in the inverse kinematic calibration of PMs that have the ill-conditioned identification matrix problem is compared to that of classical regularization methods, including the Truncated Singular Value Decomposition (TSVD) method and Tikhonov method, in simulations. Then, the kinematic calibration method is applied to a 3- PSS/S spherical PM prototype in the real world. For the 3- PSS/S spherical PM prototype, the kinematic calibration method can reduce the absolute angular errors of the end-effector from over 1.0 deg before calibration to less than 0.1 deg after calibration.
{"title":"Enhancing Kinematic Calibration Accuracy for Parallel Manipulators Based on Truncated Total Least Square Regularization","authors":"Shengqi Jian, Hao Xiong, Xiansheng Yang, Y. Lou","doi":"10.1115/1.4062948","DOIUrl":"https://doi.org/10.1115/1.4062948","url":null,"abstract":"\u0000 This paper proposes a novel kinematic calibration method to address the ill-conditioned identification matrix problem and enhance the accuracy of Parallel Manipulators (PMs). The kinematic calibration method applies the Truncated Total Least Squares (T-TLS) regularization method to the inverse kinematic calibration of PMs and doesn't have the unit inconsistency issue and configuration selection issue. The performance of the T-TLS method in the inverse kinematic calibration of PMs that have the ill-conditioned identification matrix problem is compared to that of classical regularization methods, including the Truncated Singular Value Decomposition (TSVD) method and Tikhonov method, in simulations. Then, the kinematic calibration method is applied to a 3- PSS/S spherical PM prototype in the real world. For the 3- PSS/S spherical PM prototype, the kinematic calibration method can reduce the absolute angular errors of the end-effector from over 1.0 deg before calibration to less than 0.1 deg after calibration.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2023-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49036726","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}
The present analysis addresses the generation of regular polygonal paths with any number of sides, odd or even, using special rotors revolving with uniquely prescribed motions inside fixed guidance polygons, which are coincident or similar to the trajectories to be traced. The whole rotation motion of the rotor is considered composed of a succession of Cardan motions so that the active profile of contact is formed by a polycentric sequence of circular arcs. It is shown and proved that the guidance polygon and the target polygon may coincide in the hypothesis of an odd number n of sides, whereas the guidance profile must necessarily be larger than the one to be generated for n even, in which case two equal concentric polygons rotated of θ/n between each other may be simultaneously generated by two particular points of the rotors. These devices are very useful to drill blind polygonal holes, providing the rotors of proper cutting tools and driving them by constant-speed motors through homokinetic joints.
{"title":"Kinematical approach to the drilling mechanisms for n-sided polygonal holes","authors":"F. Sorge","doi":"10.1115/1.4062914","DOIUrl":"https://doi.org/10.1115/1.4062914","url":null,"abstract":"\u0000 The present analysis addresses the generation of regular polygonal paths with any number of sides, odd or even, using special rotors revolving with uniquely prescribed motions inside fixed guidance polygons, which are coincident or similar to the trajectories to be traced. The whole rotation motion of the rotor is considered composed of a succession of Cardan motions so that the active profile of contact is formed by a polycentric sequence of circular arcs. It is shown and proved that the guidance polygon and the target polygon may coincide in the hypothesis of an odd number n of sides, whereas the guidance profile must necessarily be larger than the one to be generated for n even, in which case two equal concentric polygons rotated of θ/n between each other may be simultaneously generated by two particular points of the rotors. These devices are very useful to drill blind polygonal holes, providing the rotors of proper cutting tools and driving them by constant-speed motors through homokinetic joints.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43945961","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}
This paper explores a class of extended double-centered linkages and presents two novel multi-bifurcated double-centered metamorphic and reconfigurable mechanisms. Higher order kinematic analyses and singular value decomposition are combined to demonstrate the characteristics of multi-furcation and to reveal motion-branch transformation. These findings show that the presented double-centered linkages are able to evolve to distinct motion branches including two spherical 4R linkages, linesymmetric Bricard linkage or Bennett linkage. Furthermore, by exploring the local properties of singular configurations on geometric constraints and algebraic relationships, a systematic approach for the synthesis of the singular configurations can be designed to discover more novel multi-bifurcated metamorphic and reconfigurable mechanisms.
{"title":"Multi-Furcation Variations of Two Novel Double-Centered Mechanisms Based on Higher Order Kinematic Analyses and Singular Value Decomposition","authors":"Zhao Tang, J. Dai","doi":"10.1115/1.4062915","DOIUrl":"https://doi.org/10.1115/1.4062915","url":null,"abstract":"\u0000 This paper explores a class of extended double-centered linkages and presents two novel multi-bifurcated double-centered metamorphic and reconfigurable mechanisms. Higher order kinematic analyses and singular value decomposition are combined to demonstrate the characteristics of multi-furcation and to reveal motion-branch transformation. These findings show that the presented double-centered linkages are able to evolve to distinct motion branches including two spherical 4R linkages, linesymmetric Bricard linkage or Bennett linkage. Furthermore, by exploring the local properties of singular configurations on geometric constraints and algebraic relationships, a systematic approach for the synthesis of the singular configurations can be designed to discover more novel multi-bifurcated metamorphic and reconfigurable mechanisms.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42402392","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}
Slender beams serve as typical flexible components to transfer motion, force, and energy in compliant mechanisms (CMs). Therefore, the accurate and efficient kinetostatic modeling for the slender beams are highly needed in the synthesis and analysis of compliant mechanisms. Several impressive and great modeling methods have been completed by the pioneering researchers based on the governing equation of slender beams, which can solve the deflection of the beam while the beam-tip loads are known. However, parts of the beam-tip loads are unknown in some scenarios and the traditional governing equation becomes inefficient in these scenarios. The aim of this paper is to propose a novel modeling method for the compliant mechanism, which can solve the large deflection problem without iterative algorithm. In this research, a novel governing equation of slender beams has been established based on the Castigliano&s principle and simplified by the differential geometry. In the proposed governing equation, the statically force equilibrium equations and geometric constraint equations between different slender beams can be established in the boundary conditions, so the model of compliant mechanisms can be solved directly even if parts of the beam's tip loads and displacements are unknown. The proposed governing equation provides the deformed shapes and cross-sectional loads of the slender beams, which help the designer to check the mechanical interference and strength in the design process. The numerical examples are presented to demonstrate the feasibility of proposed method.
{"title":"Modeling Method for Static Large Deflection Problem of Curved Planar Beams in Compliant Mechanisms Based on a Novel Governing Equation","authors":"Jingyu Jiang, Song Lin, Hanchao Wang, N. Modler","doi":"10.1115/1.4062916","DOIUrl":"https://doi.org/10.1115/1.4062916","url":null,"abstract":"\u0000 Slender beams serve as typical flexible components to transfer motion, force, and energy in compliant mechanisms (CMs). Therefore, the accurate and efficient kinetostatic modeling for the slender beams are highly needed in the synthesis and analysis of compliant mechanisms. Several impressive and great modeling methods have been completed by the pioneering researchers based on the governing equation of slender beams, which can solve the deflection of the beam while the beam-tip loads are known. However, parts of the beam-tip loads are unknown in some scenarios and the traditional governing equation becomes inefficient in these scenarios. The aim of this paper is to propose a novel modeling method for the compliant mechanism, which can solve the large deflection problem without iterative algorithm. In this research, a novel governing equation of slender beams has been established based on the Castigliano&s principle and simplified by the differential geometry. In the proposed governing equation, the statically force equilibrium equations and geometric constraint equations between different slender beams can be established in the boundary conditions, so the model of compliant mechanisms can be solved directly even if parts of the beam's tip loads and displacements are unknown. The proposed governing equation provides the deformed shapes and cross-sectional loads of the slender beams, which help the designer to check the mechanical interference and strength in the design process. The numerical examples are presented to demonstrate the feasibility of proposed method.","PeriodicalId":49155,"journal":{"name":"Journal of Mechanisms and Robotics-Transactions of the Asme","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44762749","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}