Sensors for Assistive Robotic Drinking with Physical Contact

This paper proposes two sensor systems for human robot interaction in assistive drinking tasks for motion impaired people. The first sensor system uses a capacitive and resistive sensor to detect proximity and measure contact forces between the user and a regular drinking cup. The cup is held by a robot with a three finger gripper. Control strategies for the drinking process with a regular cup using both the capacitive and resistive measurements were developed and tested. The control strategies were rated by the subjects with a NASA RTLX questionnaire. Statistically significant differences between both strategies are not evident. The second sensor system uses a System on Chip (SoC) with four sensors. It enables motion impaired users to stop the robot without contact to the robot. This is accomplished with a robust detection of a human blowing on the sensor. A sensor fusion algorithm is used for detection. The results suggest the usage of both sensing methods in further robotic systems. However, the detection of a human blow should undergo further tests with motion impaired people.