Force Estimation at the Bionic Soft Arm�s Tool-Center-Point during the Interaction with the Environment

Soft continuum robots enable new application areas in contrast to standard rigid robots, such as inter- action with a varying environment. Due to their compliant continuous structure, they are inherently safe and adaptive to environmental conditions. In this paper, the interaction with the environment is performed at the tool-center-point of a soft continuum manipulator and is realized by a hybrid force-position control. For this, a force estimation model is derived to substitute the force sensor at the tool-center-point. The force estimation is probabilistic and relies on normal distributions considering model parameters and deviations from model identification of the soft continuum robot. It also provides a qualitative measure for the contact estimation. This paper first presents the probabilistic force estimation model and then shows the hybrid force-position control using the presented model. From the results, it is concluded that force sensing is replaceable for the environment interaction.