{"title":"Large-Stroke Constant-Force Mechanisms Utilizing Second Bending Mode of Flexible Beams: Evaluation Metrics and Design Approach","authors":"Fulei Ma, Guimin Chen, Wang Haitian","doi":"10.1115/detc2019-97813","DOIUrl":"https://doi.org/10.1115/detc2019-97813","url":null,"abstract":"\u0000 Compliant constant-force mechanisms (CCFMs), which provide a near constant force output over a range of displacement, can benefit many applications. This work proposes a novel large-stroke CCFM (abbreviated as B2CCFM) that utilizes the second bending mode of flexible beams. Two general nondimensionalized metrics, one describing the variation of output force and the other describing the operational displacement, are proposed to effectively characterize the performances of various CCFMs. Based on the general metrics, design formulas that can help designers quickly find suitable B2CCFM design for a specific application are obtained. A kinetostatic model for B2CCFM is also provided based on the chained beam constrain model (CBCM) to verify B2CCFM designs. An example accompanied with a prototype is presented to verify this novel CCFM and the effectiveness of the design formulas. The experimental results show that the B2CCFM example outputs a constant-force in a range as large as 45% of the beam length with variation less than 4.7%. The nondimensionalized metrics were demonstrated in comparison of several CCFMs, and the comparison results show the superior performances of B2CCFMs.","PeriodicalId":178253,"journal":{"name":"Volume 5A: 43rd Mechanisms and Robotics Conference","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117013475","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}
{"title":"Kinematic Optimization of a 2-DOF U, 2PSS Parallel Wrist Device","authors":"Neil M. Bajaj, A. Dollar","doi":"10.1115/detc2019-98108","DOIUrl":"https://doi.org/10.1115/detc2019-98108","url":null,"abstract":"\u0000 The wrist plays the crucial role of orienting a hand or end effector without significant translational motion, a critical requirement of successful manipulation. In this paper, we present the kinematic design optimization a two degree of freedom universal, two-prismatic-spherical-spherical (U, 2-PSS) parallel wrist mechanism. By varying the geometric parameters of the mechanism, we examine configurations that maximize the Global Conditioning Index, a metric describing the quality of the motion and torque, over the desired workspace, which mimics a healthy human wrist range of motion in circumduction (flexion/extension and abduction/adduction). We further investigate the effects of sizing constraints on the resulting optimized design which satisfies the imposed sizing constraints.","PeriodicalId":178253,"journal":{"name":"Volume 5A: 43rd Mechanisms and Robotics Conference","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114825420","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}
Matthew W. Powelson, Wesley A. Demirjian, S. Canfield
{"title":"Integrating Dry Adhesives and Compliant Suspension for Track-Type Climbing Robots","authors":"Matthew W. Powelson, Wesley A. Demirjian, S. Canfield","doi":"10.1115/detc2019-98012","DOIUrl":"https://doi.org/10.1115/detc2019-98012","url":null,"abstract":"\u0000 Climbing robots using dry adhesives in the literature typically exhibit minimal payload and are considered useful for tasks involving light-weight sensors, such as surveillance or exploration. Existing designs demonstrate small payloads primarily because they either employ minimal adhesion area or fail to distribute the adhesion forces over the adhering region of these robots. Further, existing design methods do not demonstrate scalability of payload-to-vehicle size and, in fact, indicate that such robots are not scalable. However, dry adhesives routinely demonstrate adhering pressures in the range of 20–50 kPa which suggests that a 30 × 30 cm robot could have a payload on the order of 20–50 kg.\u0000 This paper presents a step-by-step approach for designing track-type dry adhesive climbing robots to achieve high payloads. The aforementioned design steps are then experimentally validated, showing that high payloads should theoretically be possible when using dry adhesives to climb. By integrating a general adhesion model with a suspension system, this design procedure can be used to design climbing robots that distribute the payload over a large adhesive area. The models behind the design procedure (developed previously [1] but summarized here) simultaneously consider the behavior of both the adhesive material at the track-surface interface and the distribution of the adhesive forces over the full contact surface. When each of these criteria are satisfied, track-type climbing robots can be designed to carry high payloads, thus enabling applications previously thought to be impossible.","PeriodicalId":178253,"journal":{"name":"Volume 5A: 43rd Mechanisms and Robotics Conference","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130839400","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}
{"title":"Modeling, Control and Planning for Multiple Mobile Microrobots","authors":"B. Johnson, D. Cappelleri","doi":"10.1115/detc2019-98392","DOIUrl":"https://doi.org/10.1115/detc2019-98392","url":null,"abstract":"\u0000 We present the modeling, control and planning for multiple magnetic mobile microrobots actuated on a planar array of coils that generates local magnetic fields. The system is capable of actuating multiple microrobots independently. Such systems have a future in micromanufacturing and biomedical applications. The coils are modeled extensively to understand the forces generated by various coil combinations of the array, and solutions for different actuation force directions are discovered. The path planning problem is formulated as a Markov decision process that solves a policy to reach a goal from any location in the workspace. The presence of multiple robots in the workspace can interfere with their motion. Hence, the coil models are used concurrently with models of interaction force between multiple magnetic robots to plan efficient paths to reach a goal in the workspace in the presence of other robots.","PeriodicalId":178253,"journal":{"name":"Volume 5A: 43rd Mechanisms and Robotics Conference","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133498614","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}
{"title":"Designing Lightweight Tensegrity-Based Structures and Materials of Tailorable Thermal Expansion","authors":"Rochelle E. Silverman, E. Hernandez","doi":"10.1115/detc2019-97304","DOIUrl":"https://doi.org/10.1115/detc2019-97304","url":null,"abstract":"\u0000 In this work, we analyze and design structures and materials that possess custom thermal expansion. These structures and materials are composed of a base unit inspired by the tensegrity “D-bar” (or double-pyramid) topology. We derive, for the first time, analytical equations for the linearized and geometrically exact coefficients of thermal expansion (CTEs) of bi-material D-bar structures with arbitrary shape and complexity. Numerical results obtained using the geometrically exact CTE equations are compared with results obtained using the linearized CTE equations, showing that the latter are accurate only in cases where temperature changes are small. Further results show that D-bar structures of low complexity can produce a wide range of CTEs, including positive, zero, and negative values. These CTE values are exhibited for a range of materials that allows for easy manufacturing (materials with CTE ratios as low as 2). Thus, it is concluded that D-bar structures show promise for applications in aerospace engineering and other fields where new materials of tailorable thermal expansion are needed to decrease the substantial thermal stresses caused by large temperature changes.","PeriodicalId":178253,"journal":{"name":"Volume 5A: 43rd Mechanisms and Robotics Conference","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129616910","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}
{"title":"Design of a Triad-Pod Kinematic Flexure Mount for a Primary Mirror in Space Telescope at Cryogenic Temperature","authors":"Tonglong Huo, Jingjun Yu, Hongzhe Zhao","doi":"10.1115/detc2019-97812","DOIUrl":"https://doi.org/10.1115/detc2019-97812","url":null,"abstract":"\u0000 The paper mainly proposed a novel kinematic triad-pod flexure mount for supporting a primary mirror in space. This kind of mount is constructed by three identical pods, each of them is consisted of four rotation flexures with virtual rotation center. The mount can realize great releasement of thermal stress effect on primary mirror caused by CTE (Coefficient of Thermal Expansion) mismatch between baseplate and mirror at cryogenic temperature. Based on principles of kinematic design, the paper firstly proposes a mount configuration with three pods arranged with inclined angle. Then, the structure of pod is designed in detail, and compliance model is established. A study case is employed to illustrate how to design a triad-pod mount with higher supporting stiffness and large radialcompensate compliance. Finally, simulations by FEM are implemented to verify and analyze the performances of the proposed mount. The results demonstrate that the mount can further reduce the thermal stress in primary mirror while maintaining nearly indistinctive supporting stiffness than traditional three-bipod mount. Hence, the proposed mount can provide foundation to achieve a mount with greater performances for supporting a large-aperture mirror at a wider range of temperature.","PeriodicalId":178253,"journal":{"name":"Volume 5A: 43rd Mechanisms and Robotics Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128716445","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}
{"title":"Design of a Robotic Cannula for Robotic Lumber Discectomy","authors":"Yang Ding, B. Johnson, D. Cappelleri","doi":"10.1115/detc2019-97365","DOIUrl":"https://doi.org/10.1115/detc2019-97365","url":null,"abstract":"\u0000 In this paper, the design of the robotic cannula for minimally invasive robotic lumbar discectomy is presented. Lumbar discectomy is the surgery to remove the herniated disc material that is pressing on a nerve root or spinal cord. Recently, a robotic approach to performing this procedure has been proposed that utilizes multiple teleoperated articulated instruments inserted into the surgical workspace using a single cannula. In this paper, we propose a new robotic cannula system to work in conjunction with this new procedure. It allows for the independent teleoperated control of the axial position and rotation of up to three surgical instruments at the same time. The mechanical design, controller design, and prototype of new system are presented in this paper demonstrating a fully functioning device for this application. A novel worm gear and rack system allow for the instrument translation while and embedded gear trains produce the rotational movement. Steady-state errors of less than 50 μm for translation and less than 2° for rotational motion are obtained.","PeriodicalId":178253,"journal":{"name":"Volume 5A: 43rd Mechanisms and Robotics Conference","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123910984","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}
{"title":"Stiffness Based Stability Enhancement in Human-Robot Collaboration","authors":"S. Jujjavarapu, E. Esfahani","doi":"10.1115/detc2019-98506","DOIUrl":"https://doi.org/10.1115/detc2019-98506","url":null,"abstract":"\u0000 This paper presents the importance of endpoint stiffness and its role in improving the interaction stability of a human-robot collaborative task. A low effort collaborative task is simulated with the help of an admittance controlled robot. The performance of this robot for different levels of grasp stiffness are compared and a solution in the form of a Variable Stiffness Mechanism is provided. This mechanism provides an opportunity to modify the stiffness at the port of interaction based on two measures, an instability index in the frequency domain, and human muscle contraction in the time domain. Experimental results show an improvement in the performance and stability for the system with high stiffness vs low stiffness. Human muscle contraction provides a time instant at which the stiffness has to be modified and the instability index value provides information about the direction in which the stiffness has to be modified.","PeriodicalId":178253,"journal":{"name":"Volume 5A: 43rd Mechanisms and Robotics Conference","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115680365","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}
Daniel R. McArthur, A. B. Chowdhury, D. Cappelleri
{"title":"Autonomous Door Opening With the Interacting-BoomCopter UAV","authors":"Daniel R. McArthur, A. B. Chowdhury, D. Cappelleri","doi":"10.1115/detc2019-97397","DOIUrl":"https://doi.org/10.1115/detc2019-97397","url":null,"abstract":"\u0000 This paper presents the design of a light-weight, compliant end-effector and an image processing strategy that together enable the Interacting-BoomCopter (I-BC) unmanned aerial vehicle (UAV) to perform an autonomous door opening task. Autonomy is achieved through the use of feedback from an on-board camera for door detection & localization, and embedded force and distance sensors in the end-effector for detecting the physical interaction with the door. The results of several experimental flight tests are presented in which the end-effector and image processing strategy were deployed on the I-BC to successfully open a small enclosure door autonomously.","PeriodicalId":178253,"journal":{"name":"Volume 5A: 43rd Mechanisms and Robotics Conference","volume":"136 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116308735","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}
Pratheek Bagivalu Prasanna, A. Midha, Sushrut G. Bapat
{"title":"Classification of Compliant Mechanisms and Determination of the Degrees of Freedom Using the Concepts of Compliance Number and Pseudo-Rigid-Body Model","authors":"Pratheek Bagivalu Prasanna, A. Midha, Sushrut G. Bapat","doi":"10.1115/detc2019-98522","DOIUrl":"https://doi.org/10.1115/detc2019-98522","url":null,"abstract":"\u0000 Understanding the kinematic properties of a compliant mechanism has always proved to be a challenge. A concept of compliance number offered earlier emphasized the development of terminology that aided in its determination. A method to evaluate the elastic degrees of freedom associated with the flexible segments/links of a compliant mechanism using the pseudo-rigid-body model (PRBM) concept is provided. In this process, two distinct classes of compliant mechanisms are developed involving: (i) Active Compliance and (ii) Passive Compliance. Furthermore, these also aid in a better characterization of the kinematic behavior of a compliant mechanism. A more lucid interpretation of the significance of compliance number is provided. Applications of this method to both active and passive compliant mechanisms are exemplified. Finally, an experimental procedure that aids in visualizing the degrees of freedom as calculated is presented.","PeriodicalId":178253,"journal":{"name":"Volume 5A: 43rd Mechanisms and Robotics Conference","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131986575","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}