Whisker-Based Active Tactile Perception for Contour Reconstruction

Perception using whisker-inspired tactile sensors currently faces a major challenge: the lack of active control in robots based on direct contact information from the whisker. To accurately reconstruct object contours, it is crucial for the whisker sensor to continuously follow and maintain an appropriate relative touch pose on the surface. This is especially important for localization based on tip contact, which has a low tolerance for sharp surfaces and must avoid slipping into tangential contact. In this paper, we first construct a magnetically transduced whisker sensor featuring a compact and robust suspension system composed of three flexible spiral arms. We develop a method that leverages a characterized whisker deflection profile to directly extract the tip contact position using gradient descent, with a Bayesian filter applied to reduce fluctuations. We then propose an active motion control policy to maintain the optimal relative pose of the whisker sensor against the object surface. A B-Spline curve is employed to predict the local surface curvature and determine the sensor orientation. Results demonstrate that our algorithm can effectively track objects and reconstruct contours with sub-millimeter accuracy. Finally, we validate the method in simulations and real-world experiments where a robot arm drives the whisker sensor to follow the surfaces of three different objects.

Authors

• Yixuan Dang
• Qinyang Xu
• Yu Zhang 0182
• Xiangtong Yao
• Liding Zhang
• Zhenshan Bing
• Florian Röhrbein
• Alois C. Knoll

Keywords

• Location awareness
• Surface reconstruction
• Accuracy
• Spirals
• Tracking
• Magnetic separation
• Surface morphology
• Tactile sensors
• Robot sensing systems
• Motion control
• Active Tactile Perception
• Active Control
• Gradient Descent
• Reconstruction Accuracy
• Robotic Arm
• Tactile Sensor
• Object Surface
• Local Curvature
• Suspension System
• Bayesian Filtering
• Tip Contact
• Tangential Contact
• Friction
• 3D Printing
• Magnetometer
• Kalman Filter
• Reaction Force
• Optimal State
• 2D Plane
• R-squared Values
• Hall Sensor
• Tip Position
• Normal Displacement
• Unknown Objects
• Root Locus
• Optimal Contact
• Linear Displacement
• Contact Distance
• Contact Conditions
• Tangential Direction