Failure Cases

Failure Cases on Tactile Poking

In this paper, we assume that contacting poking regions will generate reliable tactile readings, while causing minimum disturbance to object states. However, as for the light object such as the disposable cup, the gravity is extremely small, which cannot counteract the torque generated by the poking and lead to a rotation of the cup. As shown in the left figure, when the cup is under hydrostatic equilibrium, we can get F*d2 = G*d1. Hence, as shown in the right figure, the maximum force Fmax applied to the cup is equal to G*d1max/d2min. As for the big disposal cup, the maximum force is around 0.1N, which is hard to be perceived by both the tactile sensor and robotic arm and will lead to a failed tactile poking.