Experimental Performance Comparison of Bidirectional Actuator Configurations for Suspended Aerial Platforms

Abstract

Suspended payload requires bidirectional thrust actuation to control their motion. Such systems, like the small suspended aerial cliff sampling system considered in this letter, require strong bidirectional actuators capable of fine positioning and fast disturbance rejection to fight wind gusts. This letter presents a detailed experimental comparison of three bidirectional thrust actuator configurations (i.e., reverse thrust, antagonist thrusters, and variable pitch propeller) to understand their characteristics at the scale of small aerial systems. Five tests highlight the strengths and weaknesses of each configuration regarding static thrust capabilities, large and small step response, and bandwidth capabilities. This information is then used to select the best configuration for the suspended aerial cliff sampling system described, which in turn was able to sample rare cliff plants in Kaua'i in winds gusts of up to 37 km/h. The results will also help aerial roboticists make better-informed design decisions.