Frictional Detachment Between Slender Whisker and Round Obstacle

In nature, hair-like whiskers are used to detect surrounding information, such as surface texture and air flow field. The detection requires a comprehensive understanding of the relationship between whisker deformation and the contact force. With a whisker being modeled as a slender beam, the contact problem cannot be solved by small deformation beam theory and thus requires a new mechanical model to build up the relationship between whisker deformation and the contact force. In this work, the contact problem between a whisker and a round obstacle is solved, considering three factors: large deformation of the whisker, size of the obstacle, and frictional effect of the interface. Force and energy histories during the contact are analyzed under two motion modes: translation and rotation. Results show that the rotational mode is preferred in nature, because rotation of a whisker over an obstacle requires less energy for frictional dissipation. In addition, there are two types of detachment during the slip between the whisker and the obstacle. The detachment types are dependent on the whisker’s length and can be explained by the buckling theory of a slender beam.

Obstacle Avoidance System Based on Single Rotary Ultrasonic Sensor

Centering round obstacle avoidance problem, an evadible system based on the ultrasonic sensor Sens600 is presented in this paper, the sensor rotated by the stepper motor scans back and forth in horizontal plane ahead of the robot, then the system builds and updates a histogram world model with the to-and-fro range information after data processing, the safe area capture (SAC) method is applied to compute the most suitable direction among all candidates, and the steering of the robot is aligned with that direction. The experimental results demonstrate the feasibility and effectiveness of the proposed system.