Journal articles: 'Compliant contact'

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Kang, Sungchul, Yonk K. Hwang, Munsang Kim, Chongwon Lee, and Kyo-Il Lee. "A compliant controller dynamically updating the compliance center by contact localization." Robotica 16, no. 5 (September 1998): 543–50. http://dx.doi.org/10.1017/s0263574798000058.

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This paper presents a compliant control method for insertion of complex objects with concavities. Most work on robot assembly using compliant motion control schemes focuses on overcoming jamming conditions for simple peg-in-hole problems, and cannot be used for complex shapes frequently encountered in assembly applications. When an object is being inserted to a hole or slot with a small clearance, a contact path is issued to compensate for uncertainties. When the object shape is complex, however, the contact state changes several times and severely, making compliant control difficult. The algorithm presented here is capable of generating satisfactory compliant motion control in spite of changing contact states. During the execution of a nominal motion plan, it computes the actual position of the contact point from the force/torque sensor reading using a contact localization algorithm. It then dynamically updates the center for compliance to the computed contact point, and minimize the chance of jamming and unwanted collisions. The control scheme has been implemented on hardware and tested on the task of inserting a T-shape into a C-shape involving a very tight tolerance. The insertion motion was accomplished by a sequence of 2 translational and 1 rotational compliant motions, and successfully executed by the proposed compliant motion controller.

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Raja Lexshimi RG, Najibah AR, Taufiq Zahari, Lau Wei Keat, Sim Linger, Nur Ain Diyana Ismail, Zaleha MI, and Jemaima CH. "KNOWLEDGE, COMPLIANCE AND COMPLICATION OF CONTACT LENS USAGE AMONG MEDICAL STUDENTS IN UNIVERSITI KEBANGSAAN MALAYSIA MEDICAL CENTRE." Malaysian Journal of Public Health Medicine 20, no. 1 (May 1, 2020): 229–34. http://dx.doi.org/10.37268/mjphm/vol.20/no.1/art.567.

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Non-compliance to hygienic practices in contact lens wear is regarded as a significant risk factor for contact lens-related complications. Non-compliant behaviour continues to prevent efforts to improve contact lens safety despite advancements in lens materials and care solutions. The objective of this study was to identify the association between knowledge, compliance and complications of contact lens wear. A cross-sectional design was used and contact lens users among medical faculty students were identified and recruited via convenience sampling throughout October 2013 to March 2014. A total of 36 close-ended questions that focused on knowledge level, compliance to standard contact lens practice, and experience of complications were administered. A total of 188 respondents, majority of females (89.4%; n=168) participated in this study. Although majority had good knowledge level (68.1%; n=128) on care and usage of contact lens while only a small number having moderate knowledge (26.6%; n=50) and poor knowledge (5.3%; n=10), most of them were partially compliant (74.5%; n=140) to the recommended contact lens practices. However, a small group was found to be fully compliant (24.4%; n=46) and the rest being non-compliant (1.1%; n=2). There was a significant association between knowledge on contact lens usage and compliance level to standard practices (p=0.0003). In addition, a significant association also existed between compliance level to recommended practices and risk of complications from contact lens usage (p=0.023). Findings of this study showed the positive association between knowledge of contact lens usage and compliance to recommended practices and negative association between knowledge of contact lens usage and complications experienced by contact lens users. By providing basic knowledge on contact lens care and usage via education, improvement on compliance and enhancement of safety of contact lens wear could invariably be achieved.

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Manko, D. J., and W. L. Whittaker. "Inverse Dynamic Models of Closed-Chain Mechanisms With Contact Compliance." Journal of Mechanical Design 114, no. 1 (March 1, 1992): 82–86. http://dx.doi.org/10.1115/1.2916929.

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A general inverse dynamic model which is applicable to closed-chain mechanisms with contact compliance is presented. This class of mechanism has relatively rigid members and joints, but experiences compliant interactions with objects and the environment; examples include walking machines operating on natural terrain, devices for grasping a compliant object, and wheeled mobile robots. Previous approaches for formulating inverse dynamic models of compliant mechanisms have been approximations or limited to simple configurations and open-chain mechanisms. Inverse dynamic equations for closed-chain mechanisms with contact compliance are shown to be solvable sets of differential/algebraic equtaions (DAEs) which assures that stable and accurate solutions can be calculated; relevant characteristics and solutions of DAE systems are discussed.

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Stronge, W. J. "Chain Reaction From Impact on Coaxial Multibody Systems." Journal of Applied Mechanics 67, no. 3 (May 2, 2000): 632–35. http://dx.doi.org/10.1115/1.1309541.

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In a mechanism or system of “rigid” bodies that are joined or connected by compliant points of contact, an external impact at one point in the system generates a pulse of reaction force that propagates outward successively through neighboring joints or connections. At each point of contact between adjacent bodies, this wave of reaction force is just sufficient to change the relative velocities so that interpenetration of the bodies is prevented; i.e., the reactions enforce the displacement constraints. Each connection has a local wave speed that depends on the contact compliance and the mass of the adjacent bodies. Where the local wave speed is decreasing with “distance” from the external impact, the reaction impulses at neighboring contacts occur sequentially whereas if the local wave speed is increasing substantially with distance, the impulses at neighboring contacts occur simultaneously. Between these limits, the dynamics of impact of multibody systems with compliant contacts depends on coupling between time-dependent contact forces rather than some assumed timing of the resultant impulses. [S0021-8936(00)00903-X]

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Refaat, M. H., and S. A. Meguid. "Accurate modelling of compliant grippers using a new method." Robotica 16, no. 2 (March 1998): 219–25. http://dx.doi.org/10.1017/s026357479800054x.

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Current techniques which have been devised for motion planning and control of compliant multi-fingered grippers are based on the assumption of a constant compliance. The present investigation was undertaken to examine the validity of this assumption. To this end, the variational inequalities approach and the finite element method were used to formulate the general frictional contact problem. A two-step algorithm, which employs Quadratic Programming and non-differential optimization algorithms, is used to solve the resulting variational inequality and to provide the contact characteristics of compliant grippers.The proposed method is applied to a case study involving a multi-fingered compliant gripper. The equivalent stress contours and the compliance of the system were obtained and analyzed. The proposed approach, which can be applied to any contact problem in robotics, overcomes most of the difficulties and approximations evident in current simplified contact analysis techniques.

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Cannon, Jesse R., and Larry L. Howell. "A compliant contact-aided revolute joint." Mechanism and Machine Theory 40, no. 11 (November 2005): 1273–93. http://dx.doi.org/10.1016/j.mechmachtheory.2005.01.011.

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Nelson, Todd G., and Just L. Herder. "Developable compliant-aided rolling-contact mechanisms." Mechanism and Machine Theory 126 (August 2018): 225–42. http://dx.doi.org/10.1016/j.mechmachtheory.2018.04.013.

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Atanackovic, T. M., and D. T. Spasic. "On Viscoelastic Compliant Contact-Impact Models." Journal of Applied Mechanics 71, no. 1 (January 1, 2004): 134–38. http://dx.doi.org/10.1115/1.1629106.

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We study dynamics of a mass, moving on a straight line, and impacting against the rigid wall through a deformable body, that we model as a straight rod of negligible mass. The chosen constitutive model of the viscoelastic body comprises fractional derivatives of stress and strain and the restrictions on the coefficients that follow from Clausius Duhem inequality. We show that the dynamics of the problem is governed by a single differential equation of real order. The obtained equation was solved numerically. The comparison is made to the solution obtained by the Laplace transform and Post’s inversion formula. The predictions of the model concerning the duration of the impact, maximal values of the impacting force and deformation as well as the restitution coefficient are determined for several values of system parameters.

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McMonnies, Charles W. "Improving contact lens compliance by explaining the benefits of compliant procedures." Contact Lens and Anterior Eye 34, no. 5 (October 2011): 249–52. http://dx.doi.org/10.1016/j.clae.2011.06.006.

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Liang, J. W., and B. F. Feeny. "Dynamical Friction Behavior in a Forced Oscillator With a Compliant Contact." Journal of Applied Mechanics 65, no. 1 (March 1, 1998): 250–57. http://dx.doi.org/10.1115/1.2789033.

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Contact compliance, which may arise from elastic deformation near the contact point or in the surrounding structure, affects the dynamical friction behaviors in mechanical oscillators. An idealized model consisting of a mass sliding harmonically on a mass-less compliant contact produces hysteresis in friction-velocity plots. Dynamical friction features, depending on the contact stiffness, friction level, and the frequency and amplitude of oscillation, are predicted and quantified. Contact compliance can also lead to oscillations at the transition from slip to stick. Experiments and simulations verify the model and tie together phenomena of both continuous sliding and stick-slip.

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Mankame, Nilesh D., and G. K. Ananthasuresh. "A Novel Compliant Mechanism for Converting Reciprocating Translation Into Enclosing Curved Paths." Journal of Mechanical Design 126, no. 4 (July 1, 2004): 667–72. http://dx.doi.org/10.1115/1.1759360.

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This paper introduces a novel contact-aided compliant mechanism that uses intermittent contacts to convert a single translatory reciprocating input into two output curves, which intersect to enclose a two dimensional region. Contact interactions endow contact-aided compliant mechanisms with enhanced kinematic and kinetostatic capabilities. The mechanism described in this paper is designed to undergo large deformations repeatedly, without yielding by avoiding flexural joints and by using contacts to obtain the desired deformation. A single-material, joint-free and planar design makes the mechanism easy and economical to fabricate at the macro or micro scales. The design is validated experimentally by manufacturing and testing macro scale prototypes. Two potential applications that motivated this mechanism are also noted.

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Yu, Jie, Jinkui Chu, Yang Li, and Le Guan. "An improved compliant contact force model using a piecewise function for impact analysis in multibody dynamics." Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics 234, no. 2 (January 14, 2020): 424–32. http://dx.doi.org/10.1177/1464419319900874.

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Contact-impact problems have attracted more and more attention in mechanical multibody systems. In the past period of time, a few compliant contact force models have been put forward. However, some compliant contact force models are only applicable to a specific range of coefficient of restitution impact problems. And, some compliant contact force models have large errors with the actual situation. In order to reduce the errors, an improved compliant contact force model is proposed in this paper, which is applicable to the whole range of coefficient of restitution impact problems. In this work, the permanent deformation is taken into account during the contact process. Meanwhile, the method of piecewise fitting is used to reduce the errors in numerical solutions. Therefore, the improved compliant contact force model uses a piecewise function for the whole range of coefficient of restitution. In order to illustrate the situation, six independent contact force models are numerically analyzed by using Matlab codes. The result shows that the improved compliant contact force model in this paper is applicable to both soft and hard impact and nearer to the actual situation.

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Ji, Xuerong, and Jing Xiao. "Planning Motions Compliant to Complex Contact States." International Journal of Robotics Research 20, no. 6 (June 2001): 446–65. http://dx.doi.org/10.1177/02783640122067480.

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Richter, Doris, Kathy Dumbleton, Sarah Guthrie, Craig Woods, Lyndon Jones, and Desmond Fonn. "Patient and practitioner compliance with silicone hydrogel and daily disposable lens replacement in Canada." Canadian Journal of Optometry 72, no. 1 (February 1, 2010): 10. http://dx.doi.org/10.15353/cjo.72.633.

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Purpose: To assess current recommendations by optometrists for replacement frequency (RF) of silicone hydrogels (SH) and daily disposable (DD) contact lenses in Canada, determine rates of non-compliance with recommendations by both the optometrist and patient, and investigate reasons for non-compliance. Methods: Survey packages were sent to optometrists in Canada who had agreed to participate. Patients completed survey questions regarding demographics and contact lens wearing patterns, including recommended and actual contact lens RF. Optometrists were asked to provide lens information and their recommendation for RF. Fifty-eight optometrists returned 654 surveys, of which 578 were eligible for analysis. Results: Seventy percent of patients were female with a median age of 32 years. Lens type distribution was 18% DD, 35% two-week SH, and 47% one-month SH. Six percent were worn for extended wear. Daily wear median wearing time was 12 hours/day, a median of five days/week for DD, seven days/week for SH (two-week and one-month). Optometrists’ recommendations were non-compliant with the manufacturers’ recommended RF for 6% of DD, 35% of two week, and 2% of one-month patients. Patients were non-compliant with recommendations from both the manufacturer and optometrist for 12% of DD, 43% of two-week, and 31% of one-month lens wearers. The most common reason for non-compliance was forgetting which day to replace lenses. Fifty-six percent thought a reminder system would help with compliance. A higher proportion of compliant patients followed the RF because of confidence in their optometrist. Conclusions: Optometrists generally recommended RFs consistent with manufacturers’ recommendations for DD and one-month SH lenses but often recommended longer intervals for two-week SH lenses. Patients were most compliant when wearing DD lenses and least compliant when wearing two-week SH lenses. Communication between the patient and optometrists concerning the risks of non-compliance, or initiating a reminder system might improve compliance.

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Ponik, Suzanne M., Steven M. Trier, Michele A. Wozniak, Kevin W. Eliceiri, and Patricia J. Keely. "RhoA is down-regulated at cell–cell contacts via p190RhoGAP-B in response to tensional homeostasis." Molecular Biology of the Cell 24, no. 11 (June 2013): 1688–99. http://dx.doi.org/10.1091/mbc.e12-05-0386.

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Breast epithelial cells cultured in three-dimensional (3D) collagen gels undergo ductal morphogenesis when the gel is compliant and they can achieve tensional homeostasis. We previously showed that this process requires down-regulation of Rho in compliant collagen gels, but the mechanism remains undefined. In this study, we find that p190RhoGAP-B, but not p190RhoGAP-A, mediates down-regulation of RhoA activity and ductal morphogenesis in T47D cells cultured in compliant 3D collagen gels. In addition, both RhoA and p190RhoGAP-B colocalize with p120-catenin at sites of cell–cell contact. The association between p190RhoGAP-B and p120-catenin is regulated by matrix compliance such that it increases in compliant vs. rigid collagen gels. Furthermore, knockdown of p120-catenin disrupts ductal morphogenesis, disregulates RhoA activity, and results in loss of p190B at cell–cell contacts. Consistent with these findings, using a RhoA-specific FRET biosensor (RhoA-FLARE.sc), we determined spatial RhoA activity to be significantly decreased at cell–cell contacts versus cell–ECM adhesions, and, of importance, spatial RhoA activity is regulated by p190B. This finding suggests that RhoA exists as an inactive pool at cell–cell contacts and is recruited to cell–ECM contacts within stiff matrices. Overall, these results demonstrate that RhoA is down-regulated at cell–cell contacts through p190RhoGAP-B, which is localized to cell–cell contacts by association with p120-catenin that is regulated by tensional homeostasis.

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Zhang, Dingzhi, Yilun Sun, and Tim C. Lueth. "Design of a novel tendon-driven manipulator structure based on monolithic compliant rolling-contact joint for minimally invasive surgery." International Journal of Computer Assisted Radiology and Surgery 16, no. 9 (July 7, 2021): 1615–25. http://dx.doi.org/10.1007/s11548-021-02442-w.

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Abstract Purpose Compliant mechanisms are commonly used in the design of manipulator and surgical robotic tools for minimally invasive surgery (MIS) thanks to their compactness, ability of miniaturization and lower part count. However, conventional compliant joint has higher internal stiffness, which limits the bending radius. To overcome this problem, a novel tendon-driven manipulator structure based on monolithic compliant rolling-contact joint (CRCJ) is proposed. Methods The proposed rolling-contact mechanism is used to prevent cable slack during actuation, which occurs in conventional compliant joint design. By means of selective laser sintering (SLS) technique, the CRCJ can be fabricated in a monolithic structure, thus granting the CRCJ both the advantages of compliant joints and rolling-contact mechanism. Simulations with nonlinear finite element analysis (FEA) and experiments were conducted to evaluate and compare the mechanical properties of the proposed CRCJ with conventional leaf-type compliant joint including the bending and compliant motion. Results Experimental results showed that the CRCJ has lower bending stiffness, higher maximum bending angle (over $$180^{\circ }$$ 180 ∘ ) and a higher compliance compared to conventional compliant hinges, which allows a larger workspace and reduces the possibility of tissue injury. Agreement was also found between the nonlinear FEA and experiments regarding the relation between actuation force and bending angle. A primary prototype of a 3-DOF handheld laparoscopic manipulator with a diameter of 7 mm was further developed. Conclusion A dexterous tendon-driven monolithic manipulator structure based on CRCJ for MIS is proposed. A preliminary prototype of a handheld laparoscopic manipulator demonstrates the capability of the CRCJ for steerable medical devices. However, design improvements based on FEA and application-orientated prototypes considering anatomical requirements still show room for improvements.

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Faustini, Mario C., Richard H. Crawford, Richard R. Neptune, William E. Rogers, and Gordon Bosker. "Design and Analysis of Orthogonally Compliant Features for Local Contact Pressure Relief in Transtibial Prostheses." Journal of Biomechanical Engineering 127, no. 6 (July 7, 2005): 946–51. http://dx.doi.org/10.1115/1.2049331.

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A very attractive advantage of manufacturing prosthetic sockets using solid freeform fabrication is the freedom to introduce design solutions that would be difficult to implement using traditional manufacturing techniques. Such is the case with compliant features embedded in amputee prosthetic sockets to relieve contact pressure at the residual limb-socket interface. The purpose of this study was to present a framework for designing compliant features to be incorporated into transtibial sockets and manufacturing prototypes using selective laser sintering (SLS) and Duraform™ material. The design process included identifying optimal compliant features using topology optimization algorithms and integrating these features within the geometry of the socket model. Using this process, a compliant feature consisting of spiral beams and a supporting external structure was identified. To assess its effectiveness in reducing residual limb-socket interface pressure, a case study was conducted using SLS manufactured prototypes to quantify the difference in interface pressure while a patient walked at his self-selected pace with one noncompliant and two different compliant sockets. The pressure measurements were performed using thin pressure transducers located at the distal tibia and fibula head. The measurements revealed that the socket with the greatest compliance reduced the average and peak pressure by 22% and 45% at the anterior side distal tibia, respectively, and 19% and 23% at the lateral side of the fibula head, respectively. These results indicate that the integration of compliant features within the socket structure is an effective way to reduce potentially harmful contact pressure and increase patient comfort.

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Yao, J. Q. "Contact Mechanics of Soft Layer Artificial Hip Joints: Part 1: General Solutions." Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 208, no. 4 (December 1994): 195–205. http://dx.doi.org/10.1243/pime_proc_1994_208_289_02.

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Unlike natural synovial joints, which are lubricated with a full fluid film lubrication mechanism, conventional artificial hip joints are lubricated with a mixed lubrication mechanism. Recently, however, a new generation of artificial hip joints employing compliant layers to mimic the compliance of articular cartilage in natural synovial joints have been developed to provide fluid film lubrication in these joints. While satisfactory lubrication can be achieved by employing soft layers, compliant thin layers are susceptible to the debonding between the soft layer and its stiffer substrate and long-term mechanical fatigue failure. Stress analyses for different designs of such joints are therefore important. In the present paper, the circular contact between a rigid sphere and an elastomeric layer bonded on to a rigid substrate has been analysed with a novel semi-analytical approach. The detailed contact parameters (the contact radius, the maximum surface deformation, the contact pressure and the contact stress inside the layer) have been examined for a wide range of aspect ratios (0 ≤ a/ht ≤ 100).

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Najjar, Dany M., S. Gulderen Aktan, Christopher J. Rapuano, Peter R. Laibson, and Elisabeth J. Cohen. "Contact lens–related corneal ulcers in compliant patients." American Journal of Ophthalmology 137, no. 1 (January 2004): 170–72. http://dx.doi.org/10.1016/s0002-9394(03)00722-0.

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Halverson, Peter A., Larry L. Howell, and Spencer P. Magleby. "Tension-based multi-stable compliant rolling-contact elements." Mechanism and Machine Theory 45, no. 2 (February 2010): 147–56. http://dx.doi.org/10.1016/j.mechmachtheory.2008.11.013.

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de Vicente, J., J. R. Stokes, and H. A. Spikes. "Rolling and sliding friction in compliant, lubricated contact." Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 220, no. 2 (February 2006): 55–63. http://dx.doi.org/10.1243/13506501jet90.

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Baek, Stanley S., and Ronald S. Fearing. "Reducing Contact Resistance Using Compliant Nickel Nanowire Arrays." IEEE Transactions on Components and Packaging Technologies 31, no. 4 (December 2008): 859–68. http://dx.doi.org/10.1109/tcapt.2008.2004576.

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ElMaraghy, H. A., and S. Payandeh. "Contact prediction and reasoning for compliant robot motions." IEEE Transactions on Robotics and Automation 5, no. 4 (1989): 533–38. http://dx.doi.org/10.1109/70.88068.

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Dollar, Aaron M., Leif P. Jentoft, Jason H. Gao, and Robert D. Howe. "Contact sensing and grasping performance of compliant hands." Autonomous Robots 28, no. 1 (August 26, 2009): 65–75. http://dx.doi.org/10.1007/s10514-009-9144-9.

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Maraghy, H. A., and S. Payandeh. "Knowledge-based contact reasoning for compliant robot tasks." International Journal of Advanced Manufacturing Technology 3, no. 5 (November 1988): 61–80. http://dx.doi.org/10.1007/bf02601561.

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Wang, Kai, and Xing Song Wang. "Adaptive Impedance Control for a Tendon-Sheath-Driven Compliant Gripper." Applied Mechanics and Materials 532 (February 2014): 74–77. http://dx.doi.org/10.4028/www.scientific.net/amm.532.74.

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This paper investigates the feasibility of adaptive impedance control scheme for compliant gripper. A compliant gripper was designed for manipulation tasks requiring precision position and force control. The gripper is actuated by tendon-sheath transmission system and use strain gages to measure both the displacement and gripping force. Position based impedance control is used to control the contact force to made the gripper more compliantly. Due to the nonlinear of the structure; it is difficult to establish the mathematic model and kinematical equations. Therefore, combine model reference adaptive control strategy with impedance control to realize the soft control of the compliant gripper.

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Marigold, Daniel S., and Aftab E. Patla. "Adapting Locomotion to Different Surface Compliances: Neuromuscular Responses and Changes in Movement Dynamics." Journal of Neurophysiology 94, no. 3 (September 2005): 1733–50. http://dx.doi.org/10.1152/jn.00019.2005.

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Knowledge of how the nervous system deals with surfaces with different physical properties such as compliance that challenge balance during locomotion is of importance as we are constantly faced with these situations every day. The purpose of this study was to examine the control of center of mass (COM) and lower limb dynamics and recovery response modulation of muscle activity during locomotion across an unexpected compliant surface and in particular, scaling behavior across different levels of compliance. Eight young adults walked along a walkway and stepped on an unexpected compliant surface in the middle of the travel path. There were three different levels of surface compliance, and participants experienced either no compliant surface or one of the three compliant surfaces during each trial that were presented in a blocked or random fashion. Whole body kinematics were collected along with surface electromyography (EMG) of selected bilateral lower limb and trunk muscles. The recovery response to the first compliant-surface trial demonstrated muscle onset latencies between 97 and 175 ms, and activity was modulated while on the compliant surface. Vertical COM trajectory was not preserved after contact with the compliant surface: peak vertical COM, while on the compliant surface was lower than when on stable ground. Perturbed-limb knee flexion after toe-off increased with increased surface compliance, which enabled toe clearance with the ground to be similar to control trials. The results suggest that stepping off of a compliant surface is actively modulated by the CNS and is geared toward maintaining dynamic stability.

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Xu, Chang, Yuxiang Wang, Steven C. Hauser, and Gregory J. Gerling. "In the Tactile Discrimination of Compliance, Perceptual Cues in Addition to Contact Area Are Required." Proceedings of the Human Factors and Ergonomics Society Annual Meeting 62, no. 1 (September 2018): 1535–39. http://dx.doi.org/10.1177/1541931218621347.

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In our ability to discriminate compliant, or ‘soft,’ objects, we rely upon information acquired from interactions at the finger pad. We have yet to resolve the most pertinent perceptual cues. However, doing so is vital for building effective, dynamic displays. By introducing psychophysical illusions through spheres of various size and elasticity, we investigate the utility of contact area cues, thought to be key in encoding compliance. For both active and passive touch, we determine finger pad-to-stimulus contact areas, using an ink-based procedure, as well as discrimination thresholds. The findings indicate that in passive touch, participants cannot discriminate certain small compliant versus large stiff spheres, which generate similar contact areas. In active touch, however, participants easily discriminate these spheres, though contact areas remain similar. Supplementary cues based on stimulus rate and/or proprioception seem vital. One cue that does differ for illusion cases is finger displacement given a volitionally applied force.

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Chen, Yang, and Xue Zhu Wang. "Shared Compliant Control of Teleoperation Based on Stiffness Feedback." Applied Mechanics and Materials 321-324 (June 2013): 1482–86. http://dx.doi.org/10.4028/www.scientific.net/amm.321-324.1482.

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In teleoperation tasks, communication delays between master and slave sides negatively affect the stability and transparency of closed loop system, and make it difficult to maintain a desired contact force. In order to improve the performance of contact force control in teleoperation under large time delays, a shared compliant control method is proposed in this paper. On the master side, the operator issues a desired contact force command according to the feedback of the contact stiffness identified on line besides motion commands. And on the slave side, a local contact force controller is designed using an adaptive Smith predictor, so as to shares control load with the operator. Experimental results show that this method can improve the force control performance, lower the difficulty of operation, and help the operator complete contact tasks with proper forces.In teleoperation tasks, communication delays between master and slave sides negatively affect the stability and transparency of closed loop system, and make it difficult to maintain a desired contact force. In order to improve the performance of contact force control in teleoperation under large time delays, a shared compliant control method is proposed in this paper. On the master side, the operator issues a desired contact force command according to the feedback of the contact stiffness identified on line besides motion commands. And on the slave side, a local contact force controller is designed using an adaptive Smith predictor, so as to shares control load with the operator. Experimental results show that this method can improve the force control performance, lower the difficulty of operation, and help the operator complete contact tasks with proper forces.

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Wiedmann, Stephen, and Bob Sturges. "Spatial Kinematic Analysis of Threaded Fastener Assembly." Journal of Mechanical Design 128, no. 1 (April 26, 2005): 116–27. http://dx.doi.org/10.1115/1.2114909.

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Compliant mechanisms for rigid part mating exist for prismatic geometries. A few instances are known of mechanisms to assemble screw threads. A comprehensive solution to this essentially geometric problem comprises at least three parts: parametric equations for nut and bolt contact in the critical starting phase of assembly, the possible space of motions between these parts during this phase, and the design space of compliant devices which accomplish the desired motions in the presence of friction and positional uncertainty. This work concentrates on the second part in which the threaded pair is modeled numerically, and contact tests are automated through software. Tessellated solid models were used during three-dimensional collision analysis to enumerate the approximate location of the initial contact point. The advent of a second contact point presented a more constrained contact state. Thus, the bolt is rotated about a vector defined by the initial two contact points until a third contact location was found. By analyzing the depth of intersection of the bolt into the nut as well as the vertical movement of the origin of the bolt reference frame, we determined that there are three types of contacts states present: unstable two-point, quasi-stable two-point, stable three point. The space of possible motions is bounded by these end conditions which will differ in detail depending upon the starting orientations. We investigated all potential orientations which obtain from a discretization of the roll, pitch, and yaw uncertainties, each of which has its own set of contact points. From this exhaustive examination, a full contact state history was determined, which lays the foundation for the design space of either compliant mechanisms or intelligent sensor-rich controls.

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Machado, Margarida, Pedro Moreira, Paulo Flores, and Hamid M. Lankarani. "Compliant contact force models in multibody dynamics: Evolution of the Hertz contact theory." Mechanism and Machine Theory 53 (July 2012): 99–121. http://dx.doi.org/10.1016/j.mechmachtheory.2012.02.010.

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Khansari, Mohammad, Ellen Klingbeil, and Oussama Khatib. "Adaptive human-inspired compliant contact primitives to perform surface–surface contact under uncertainty." International Journal of Robotics Research 35, no. 13 (July 11, 2016): 1651–75. http://dx.doi.org/10.1177/0278364916648389.

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Mankame, Nilesh D., and G. K. Ananthasuresh. "Topology optimization for synthesis of contact-aided compliant mechanisms using regularized contact modeling." Computers & Structures 82, no. 15-16 (June 2004): 1267–90. http://dx.doi.org/10.1016/j.compstruc.2004.02.024.

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Winges, Sara A., Stephanie E. Eonta, John F. Soechting, and Martha Flanders. "Effects of Object Compliance on Three-Digit Grasping." Journal of Neurophysiology 101, no. 5 (May 2009): 2447–58. http://dx.doi.org/10.1152/jn.91021.2008.

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Compared with rigid objects, grasping and lifting compliant objects presents additional uncertainties. For any static grasp, forces at the fingertips depend on factors including the locations of the contact points and the contact forces must be coordinated to maintain equilibrium. For compliant objects, the locations and orientations of the contact surfaces change in a force-dependent manner, thus changing the force requirements. Furthermore, every force adjustment then results in additional changes in object shape. This study characterized force and muscle activation patterns in this situation. Fingertip forces were measured as subjects grasped and lifted a 200-g object using their thumb, index, and ring fingers. A spring was sometimes placed under the index and/or ring finger contact surface. Surface electromyographic activity was recorded from ten hand muscles and one proximal arm muscle. The patterns of grip (normal) force and muscle activity were similar across conditions during the load and lift phases, but their amplitude depended on whether the contact surface was compliant. Specifically, the grip force increased smoothly during the load phase of the task under all conditions. To the contrary, the tangential contact (load) force did not increase monotonically when one or more of the contact surfaces were compliant, resulting in a decoupling of the grip and load forces.

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Jansen, Meredith E., Robin Chalmers, G. Lynn Mitchell, Beth T. Kinoshita, Dawn Y. Lam, Timothy T. McMahon, Kathryn Richdale, Luigina Sorbara, and Heidi Wagner. "Characterization of patients who report compliant and non-compliant overnight wear of soft contact lenses." Contact Lens and Anterior Eye 34, no. 5 (October 2011): 229–35. http://dx.doi.org/10.1016/j.clae.2011.01.001.

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Bilancia, Pietro, Mario Baggetta, Giovanni Berselli, Luca Bruzzone, and Pietro Fanghella. "Design of a bio-inspired contact-aided compliant wrist." Robotics and Computer-Integrated Manufacturing 67 (February 2021): 102028. http://dx.doi.org/10.1016/j.rcim.2020.102028.

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Bongaerts, J. H. H., K. Fourtouni, and J. R. Stokes. "Soft-tribology: Lubrication in a compliant PDMS–PDMS contact." Tribology International 40, no. 10-12 (October 2007): 1531–42. http://dx.doi.org/10.1016/j.triboint.2007.01.007.

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Xie, Kang, Lee Wells, Jaime A. Camelio, and Byeng D. Youn. "Variation Propagation Analysis on Compliant Assemblies Considering Contact Interaction." Journal of Manufacturing Science and Engineering 129, no. 5 (May 17, 2007): 934–42. http://dx.doi.org/10.1115/1.2752829.

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Dimensional variation is inherent to any manufacturing process. In order to minimize its impact on assembly products it is important to understand how the variation propagates through the assembly process. Unfortunately, manufacturing processes are complex and in many cases highly nonlinear. Traditionally, assembly process modeling has been approached as a linear process. However, many assemblies undergo highly complex nonlinear physical processes, such as compliant deformation, contact interaction, and welding thermal deformation. This paper presents a new variation propagation methodology considering the compliant contact effect, which will be analyzed through nonlinear frictional contact analysis. Its variation prediction will be accurately and efficiently conducted using an enhanced dimension reduction method. A case study is presented to show the applicability of the proposed methodology.

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Zafer, Naci, and Sezcan Yilmaz. "Frictional Compliant Haptic Contact and Deformation of Soft Objects." International Journal of Advanced Robotic Systems 13, no. 3 (January 2016): 92. http://dx.doi.org/10.5772/63937.

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Prutchi, David, and Mircea Arcan. "Dynamic contact stress analysis using a compliant sensor array." Measurement 11, no. 3 (June 1993): 197–210. http://dx.doi.org/10.1016/0263-2241(93)90039-k.

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Hippmann, Gerhard. "An Algorithm for Compliant Contact Between Complexly Shaped Bodies." Multibody System Dynamics 12, no. 4 (December 2004): 345–62. http://dx.doi.org/10.1007/s11044-004-2513-4.

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Sayers, Colin M. "Stress‐dependent seismic anisotropy of shales." GEOPHYSICS 64, no. 1 (January 1999): 93–98. http://dx.doi.org/10.1190/1.1444535.

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A simple theory for the stress‐dependent seismic anisotropy of shales can be obtained in terms of a second‐rank tensor and a fourth‐rank tensor that depend on the orientation distribution of contacts between clay platelets. The theory allows the normal and shear stiffness of the contact regions between clay platelets to be obtained as a function of stress from measurements of seismic P- and S-wave velocities for shales. The ratio of the normal‐to‐shear compliance, [Formula: see text], of the contact regions between clay particles is found to be sensitive to the saturation state of the shale. Inversion of velocity measurements for fully saturated shales shows a low value of [Formula: see text] when compared with measurements on air‐dry shales, consistent with the expected reduction in normal compliance in a fluid‐saturated, low‐permeability rock. For all shales considered, [Formula: see text] is found to be less than unity. The contacts between clay particles are therefore more compliant in shear than in compression.

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Luo, Lianzhen, and Meyer Nahon. "A Compliant Contact Model Including Interference Geometry for Polyhedral Objects." Journal of Computational and Nonlinear Dynamics 1, no. 2 (November 15, 2005): 150–59. http://dx.doi.org/10.1115/1.2162870.

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Modeling of contact with the environment is an essential capability for the simulation of space robotics system, which includes tasks such as berthing and docking. The effect of interbody contact on the robotic system has to be determined to predict potential problems in the design cycle. A compliant contact dynamics model is proposed here that considers most possible contact situations for a wide diversity of possible object shapes and using interference geometry information. A uniform formula is provided to determine the contact force as a function of geometric parameters and material properties. A corresponding geometric algorithm is provided in order to obtain the necessary geometric parameters. Some simulation results are presented based on the implementation of the geometric algorithm.

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Leff, Julian, Ruth Berkowitz, Naomi Shavit, Angus Strachan, Ilana Glass, and Christine Vaughn. "A Trial of Family Therapy v. a Relatives Group for Schizophrenia." British Journal of Psychiatry 154, no. 1 (January 1989): 58–66. http://dx.doi.org/10.1192/bjp.154.1.58.

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Schizophrenic patients living in high contact with relatives having high expressed emotion (EE) were recruited for a trial of social interventions. The patients were maintained on neuroleptic medication, while their families were randomly assigned to education plus family therapy or education plus a relatives group. Eleven out of 12 families accepted family therapy in the home, whereas only six out of 11 families were compliant with the relatives group. Non-compliance was associated with a poorer outcome for the patients in terms of the relapse rate. The relapse rate over nine months in the family therapy stream was 8%, while that in compliant families in the relatives group stream was 17%. Patients' social functioning showed small, non-significant, gains. The data from the current trial were compared with data from a previous trial. The lowering of the relapse rate in schizophrenia appears to be mediated by reductions in relatives' EE and/or face-to-face contact, and is not explained by better compliance with medication. Reduction in EE and/or contact was associated with a minuscule relapse rate (5%). Very little change occurred in families who were non-compliant with the relatives group. On the basis of these findings, we recommend that the most cost-effective procedure is to establish relatives groups in conjunction with family education and one or more initial family therapy sessions in the home. It is particularly important to offer home visits to families who are unable to or refuse to attend the relatives groups.

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Dargahi, J. "An Endoscopic and Robotic Tooth-like Compliance and Roughness Tactile Sensor." Journal of Mechanical Design 124, no. 3 (August 6, 2002): 576–82. http://dx.doi.org/10.1115/1.1471531.

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This paper reports on design, fabrication and testing of a prototype Polyvinylidene Fluoride (PVDF) tactile sensor for endoscopic and robotic applications. The sensor can measure both compliance and surface roughness. It consists of rigid and compliant elements. A relative deformation between adjacent parts of the contact object is used to measure the compliance, and the deformation of the compliant element of the sensor is used to measure the profile of a rough surface. The sensor in miniaturized form can be integrated with both endoscopic graspers and robotic end effectors. The theoretical analysis of the sensor is made and compared with experimental values. The advantages and limitations of the sensor are also discussed.

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She, Yu, Siyang Song, Hai-jun Su, and Junmin Wang. "A Parametric Study of Compliant Link Design for Safe Physical Human–Robot Interaction." Robotica 39, no. 10 (February 3, 2021): 1739–59. http://dx.doi.org/10.1017/s0263574720001472.

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SUMMARYRobots of next-generation physically interact with the world rather than be caged in a controlled area, and they need to make contact with the open-ended environment to perform their task. Compliant robot links offer intrinsic mechanical compliance for addressing the safety issue for physical human–robot interactions (pHRI). However, many important research questions are yet to be answered. For instance, how do system parameters, for example, mechanical compliance, motor torque, impact velocities, and so on, affect the impact force? how to formulate system impact dynamics of compliant robots, and how to size their geometric dimensions to maximize impact force reduction. In this paper, we present a parametric study of compliant link (CL) design for safe pHRI. We first present a theoretical model of the pHRI system that is comprised of robot dynamics, an impact contact model, and dummy head dynamics. After experimentally validating the theoretical model, we then systematically study the effects of CL parameters on the impact force in more detail. Specifically, we explore how the design and actuation parameters affect the impact force of pHRI system. Based on the parametric studies of the CL design, we propose a step-by-step process and a list of concrete guidelines for designing CL with safety constraints in pHRI. We further conduct a simulation case study to validate this design process and design guidelines.

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Song, P., P. Kraus, V. Kumar, and P. Dupont. "Analysis of Rigid-Body Dynamic Models for Simulation of Systems With Frictional Contacts." Journal of Applied Mechanics 68, no. 1 (June 16, 2000): 118–28. http://dx.doi.org/10.1115/1.1331060.

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The use of Coulomb’s friction law with the principles of classical rigid-body dynamics introduces mathematical inconsistencies. Specifically, the forward dynamics problem can have no solutions or multiple solutions. In these situations, compliant contact models, while increasing the dimensionality of the state vector, can resolve these problems. The simplicity and efficiency of rigid-body models, however, provide strong motivation for their use during those portions of a simulation when the rigid-body solution is unique and stable. In this paper, we use singular perturbation analysis in conjunction with linear complementarity theory to establish conditions under which the solution predicted by the rigid-body dynamic model is stable. We employ a general model of contact compliance to derive stability criteria for planar mechanical systems. In particular, we show that for cases with one sliding contact, there is always at most one stable solution. Our approach is not directly applicable to transitions between rolling and sliding where the Coulomb friction law is discontinuous. To overcome this difficulty, we introduce a smooth nonlinear friction law, which approximates Coulomb friction. Such a friction model can also increase the efficiency of both rigid-body and compliant contact simulation. Numerical simulations for the different models and comparison with experimental results are also presented.

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Shia, Chih-Yuan, and R. J. Stango. "Analysis of a Compliant Honing Tool for Brushing Cylindrical Surfaces." Journal of Manufacturing Science and Engineering 119, no. 3 (August 1, 1997): 441–44. http://dx.doi.org/10.1115/1.2831126.

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In this paper, a mechanics-based model is developed and I used for analyzing the steady-state configuration of brush fibers during concentric brushing of a cylindrical surface. The geometry of the problem is generalized in order to facilitate the analysis of flexible honing tools, that is, brushing tools having a spherical volume of abrasive compound attached at the end of each fiber. The integrity of the model is evaluated by examining two special cases that have a known solution, namely, (i) quasistatic contact, and (ii) dynamic contact associated with successively reduced fiber stiffness. In each case, correct results are obtained for the contact forces generated at the interface of the filament tip/cylindrical workpart surface. Also, special attention is given to examining the role that brush rotational speed plays in the response of each fiber of the honing tool, including filament/workpart contact force, torque, and filament stress.

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Suomalainen, Markku, Fares J. Abu-dakka, and Ville Kyrki. "Imitation learning-based framework for learning 6-D linear compliant motions." Autonomous Robots 45, no. 3 (March 2021): 389–405. http://dx.doi.org/10.1007/s10514-021-09971-y.

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AbstractWe present a novel method for learning from demonstration 6-D tasks that can be modeled as a sequence of linear motions and compliances. The focus of this paper is the learning of a single linear primitive, many of which can be sequenced to perform more complex tasks. The presented method learns from demonstrations how to take advantage of mechanical gradients in in-contact tasks, such as assembly, both for translations and rotations, without any prior information. The method assumes there exists a desired linear direction in 6-D which, if followed by the manipulator, leads the robot’s end-effector to the goal area shown in the demonstration, either in free space or by leveraging contact through compliance. First, demonstrations are gathered where the teacher explicitly shows the robot how the mechanical gradients can be used as guidance towards the goal. From the demonstrations, a set of directions is computed which would result in the observed motion at each timestep during a demonstration of a single primitive. By observing which direction is included in all these sets, we find a single desired direction which can reproduce the demonstrated motion. Finding the number of compliant axes and their directions in both rotation and translation is based on the assumption that in the presence of a desired direction of motion, all other observed motion is caused by the contact force of the environment, signalling the need for compliance. We evaluate the method on a KUKA LWR4+ robot with test setups imitating typical tasks where a human would use compliance to cope with positional uncertainty. Results show that the method can successfully learn and reproduce compliant motions by taking advantage of the geometry of the task, therefore reducing the need for localization accuracy.

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Cirone, Samantha A., Gregory R. Hayes, Brian L. Babcox, Mary Frecker, James H. Adair, and George A. Lesieutre. "Design of contact-aided compliant cellular mechanisms with curved walls." Journal of Intelligent Material Systems and Structures 23, no. 16 (July 17, 2012): 1773–85. http://dx.doi.org/10.1177/1045389x12453962.

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Journal articles on the topic 'Compliant contact'

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