A COMPARISON BETWEEN SERIES ELASTIC ACTUATORS FOR FOUR LEGGED DYNAMIC ROBOT APPLICATION

Arnaldo Gomes Leal Junior¹; Rafhael Milanezi de Andrade¹; Antônio Bento Filho¹

¹ UFES

doi:10.20906/CPS/COB-2015-0317

Resumo

Over the years, machine and drive systems are built to be as stiff as possible to increase bandwidth. The mechanical systems actuators are always rigidly connected to the load. However, the friction effect, impact damage and coupled actuator inertia begun to represent a great problem in some actuator's applications. To deal with these drawbacks, a series elastic actuator (SEA) which contains an elastic element in series with the mechanical energy source was created. Such an elastic element gives SEA's several unique properties compared to rigid actuators, including tolerance to impact loads, low mechanical output impedance, passive mechanical energy storage, and increased peak power output. These properties allow the SEA to have major applications in dynamic robots. This paper describes a comparison between two types of SEA, an electric serial elastic actuator (ESEA) and a hydraulic serial elastic actuator (HSEA), for four legged dynamic robot application. The parameters employed in the comparison are bandwidth, output impedance, time response, power density, dynamic range. The results indicate the HSEA is the best actuator for a weight carrying four legged dynamic robot because of its higher power density and dynamic ratio with desirable output impedance, time response and bandwidth.

Palavras-chave: SEA; actuator; force control; dynamic robot