Contact Region Estimation Based on a Vision-Based Tactile Sensor Using a Deformable Touchpad

A new method is proposed to estimate the contact region between a sensor and an object using a deformable tactile sensor. The sensor consists of a charge-coupled device (CCD) camera, light-emitting diode (LED) lights and a deformable touchpad. The sensor can obtain a variety of tactile information, such as the contact region, multi-axis contact force, slippage, shape, position and orientation of an object in contact with the touchpad. The proposed method is based on the movements of dots printed on the surface of the touchpad and classifies the contact state of dots into three types—A non-contacting dot, a sticking dot and a slipping dot. Considering the movements of the dots with noise and errors, equations are formulated to discriminate between the contacting dots and the non-contacting dots. A set of the contacting dots discriminated by the formulated equations can construct the contact region. Next, a method is developed to detect the dots in images of the surface of the touchpad captured by the CCD camera. A method to assign numbers to dots for calculating the displacements of the dots is also proposed. Finally, the proposed methods are validated by experimental results.

[1]  Hiroyuki Kajimoto,et al.  High‐resolution tactile sensor using the deformation of a reflection image , 2007 .

[2]  I. Shimoyama,et al.  A shear stress sensor for tactile sensing with the piezoresistive cantilever standing in elastic material , 2006 .

[3]  Takashi Maeno,et al.  Artificial finger skin having ridges and distributed tactile sensors used for grasp force control , 2001, Proceedings 2001 IEEE/RSJ International Conference on Intelligent Robots and Systems. Expanding the Societal Role of Robotics in the the Next Millennium (Cat. No.01CH37180).

[4]  M. Ishida,et al.  Monolithic silicon smart tactile image sensor with integrated strain sensor array on pneumatically swollen single-diaphragm structure , 2006, IEEE Transactions on Electron Devices.

[5]  J. Engel,et al.  Development of a multi-modal, flexible tactile sensing skin using polymer micromachining , 2003, TRANSDUCERS '03. 12th International Conference on Solid-State Sensors, Actuators and Microsystems. Digest of Technical Papers (Cat. No.03TH8664).

[6]  Giulio Sandini,et al.  Tactile Sensing—From Humans to Humanoids , 2010, IEEE Transactions on Robotics.

[7]  Goro Obinata,et al.  Vision-Based Tactile Sensing and Shape Estimation Using a Fluid-Type Touchpad , 2012, IEEE Transactions on Automation Science and Engineering.

[8]  Goro Obinata,et al.  Grip Force Control Using Vision-Based Tactile Sensor for Dexterous Handling , 2008, EUROS.

[9]  Goro Obinata,et al.  Multi-axis force measurement based on vision-based fluid-type hemispherical tactile sensor , 2013, 2013 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[10]  E. Adelson,et al.  Retrographic sensing for the measurement of surface texture and shape , 2009, 2009 IEEE Conference on Computer Vision and Pattern Recognition.

[11]  H. S. Wolff,et al.  iRun: Horizontal and Vertical Shape of a Region-Based Graph Compression , 2022, Sensors.

[12]  RM Crowder,et al.  Tactile Sensing , 2018, Measurement, Instrumentation, and Sensors Handbook.

[13]  Mark Lee,et al.  Review Article Tactile sensing for mechatronics—a state of the art survey , 1999 .

[14]  Goro Obinata,et al.  Vision Based Tactile Sensor Using Transparent Elastic Fingertip for Dexterous Handling , 2007 .

[15]  Masahiro Ohka,et al.  Sensing characteristics of an optical three-axis tactile sensor under combined loading , 2004, Robotica.

[16]  Roger W. Brockett,et al.  Reconstructing the Shape of a Deformable Membrane from Image Data , 2000, Int. J. Robotics Res..

[17]  Naoki Kawakami,et al.  Measurement of force vector field of robotic finger using vision-based haptic sensor , 2008, 2008 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[18]  Xiuqin Chen,et al.  Tactile sensing properties of protein-like single-helix carbon microcoils , 2006 .

[19]  M. Shimojo,et al.  A system for simultaneously measuring grasping posture and pressure distribution , 1995, Proceedings of 1995 IEEE International Conference on Robotics and Automation.

[20]  Hirofumi Suzuki,et al.  Object exploration and manipulation using a robotic finger equipped with an optical three-axis tactile sensor , 2009, Robotica.

[21]  Isao Shimoyama,et al.  1P1-I05 The Estimation of Surface Shape Using Lined Strain Sensors , 2008 .

[22]  Hiroyuki Shinoda,et al.  Digital tactile sensing elements communicating through conductive skin layers , 2002, Proceedings 2002 IEEE International Conference on Robotics and Automation (Cat. No.02CH37292).

[23]  Wen J. Li,et al.  An integrated MEMS three-dimensional tactile sensor with large force range , 2000 .

[24]  Kazuo Tanie,et al.  Development of a Finger-Shaped Tactile Sensor Using a Hemispherical Optical Waveguide , 1994 .

[25]  Naoki Kawakami,et al.  Vision-based sensor for real-time measuring of surface traction fields , 2005, IEEE Computer Graphics and Applications.

[26]  Chang Liu,et al.  Development of polyimide flex-ible tactile sensor skin , 2003 .

[27]  Y. Umetani,et al.  Soft viscoelastic robot skin capable of accurately sensing contact location of object , 1999, Proceedings. 1999 IEEE/SICE/RSJ. International Conference on Multisensor Fusion and Integration for Intelligent Systems. MFI'99 (Cat. No.99TH8480).

[28]  Y. Ito,et al.  Robust Slippage Degree Estimation Based on Reference Update of Vision-Based Tactile Sensor , 2011, IEEE Sensors Journal.

[29]  Hiroyuki Shinoda,et al.  Wire-Free Tactile Sensing Element Based on Optical Connection , 2002 .

[30]  W. A. Bullough.  Liquid state force and displacement devices , 1991 .

[31]  Goro Obinata,et al.  Contact State Estimation by Vision-Based Tactile Sensors for Dexterous Manipulation with Robot Hands Based on Shape-Sensing , 2011 .

[32]  Giorgio Metta,et al.  A tactile sensor for the fingertips of the humanoid robot iCub , 2010, 2010 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[33]  Jean Arlat,et al.  State of the Art Survey , 2022 .