Simultaneous Motion and Force Sensing for a Flexure Finger

Flexure graspers have been identified as a bioinspired evolution in robotics to adapt to unpredictable disturbances and uncertainties in unstructured environments. However, these soft robots with infinite degrees of freedom (DOFs) have brought in many technical challenges, among which is the sensing of spatially-distributed and time-varying force and displacement fields for feedback control with a finite number of nodal measurements. This paper proposes a simultaneous motion and force sensing method based on discrete strain data with an illustrative application to a flexure finger that can serve as an actuation and sensing unit in a robotic hand. The method is rigorously formulated by introducing the strain mode shapes and correlating continuous displacement and force/moment distributions with curvatures of deformation. Design analysis of the flexure robotic finger is presented and the compliant composite joints are fabricated via shape deposition with embedded strain gauges. The proposed sensing method is numerically verified with finite element analysis and experimentally validated on a prototype of the flexure finger.

[1]  Conor J. Walsh,et al.  Shape Deposition Manufacturing of a Soft, Atraumatic, and Deployable Surgical Grasper , 2015 .

[2]  Robert J. Webster,et al.  Design and Kinematic Modeling of Constant Curvature Continuum Robots: A Review , 2010, Int. J. Robotics Res..

[3]  Arianna Menciassi,et al.  A Machine-Learning-Based Approach to Solve Both Contact Location and Force in Soft Material Tactile Sensors. , 2019, Soft robotics.

[4]  Robert J. Wood,et al.  Soft Robotic Grippers for Biological Sampling on Deep Reefs , 2016, Soft robotics.

[5]  Kok-Meng Lee,et al.  Articular Geometry Reconstruction for Knee Joint with a Wearable Compliant Device , 2019, Robotica.

[6]  Aaron P. Gerratt,et al.  Elastomeric Electronic Skin for Prosthetic Tactile Sensation , 2015 .

[7]  Kok-Meng Lee,et al.  Compliant joint design and flexure finger dynamic analysis using an equivalent pin model , 2013 .

[8]  Caihua Xiong,et al.  Design and Implementation of an Anthropomorphic Hand for Replicating Human Grasping Functions , 2016, IEEE Transactions on Robotics.

[9]  Qingsong Xu,et al.  Design and Development of a Novel Compliant Gripper With Integrated Position and Grasping/Interaction Force Sensing , 2017, IEEE Transactions on Automation Science and Engineering.

[10]  Jiajie Guo,et al.  A Modal Expansion Method for Displacement and Strain Field Reconstruction of a Thin-Wall Component During Machining , 2018, IEEE/ASME Transactions on Mechatronics.

[11]  Cecilia Laschi,et al.  Soft robotics: a bioinspired evolution in robotics. , 2013, Trends in biotechnology.

[12]  Robert J. Wood,et al.  Toward a modular soft sensor-embedded glove for human hand motion and tactile pressure measurement , 2014, 2014 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[13]  Mark R. Cutkosky,et al.  Tunable Contact Conditions and Grasp Hydrodynamics Using Gentle Fingertip Suction , 2019, IEEE Transactions on Robotics.

[14]  Robert D. Howe,et al.  Contact sensing and grasping performance of compliant hands , 2010, Auton. Robots.

[15]  Xiaohua Yi,et al.  Large-Deformation Analysis and Experimental Validation of a Flexure-Based Mobile Sensor Node , 2012, IEEE/ASME Transactions on Mechatronics.

[16]  Aaron M. Dollar,et al.  The Smooth Curvature Model: An Efficient Representation of Euler–Bernoulli Flexures as Robot Joints , 2012, IEEE Transactions on Robotics.

[17]  Bruno Siciliano,et al.  The DEXMART hand: Mechatronic design and experimental evaluation of synergy-based control for human-like grasping , 2014, Int. J. Robotics Res..