Efficient UAS sensor mounting using contact force feedback

Uncrewed Aircraft Systems (UAS) are becoming widely used in the inspection of structures. While in most applications, the UAS are used for remote\contactless inspections, there are cases where the UAS need to contact the structure and do a measurement or deliver a sensor package. In this paper, we work on the autonomous deployment and retrieval of sensor packages to the underside of structures. The accurate positioning and reliable mounting of the package below a structure is a challenging problem. Based on our prior work in the field, we develop a new control and mission framework that takes into account the estimated contact force to ensure that the package is firmly attached during deployment and securely retrieved when the mission ends. The new system has been thoroughly tested in numerous lab experiments that mimic the conditions of an outdoor setting, and experimental results show that the new approach greatly increases the reliability of the system.