Naslov
Hibridno upravljanje podatnošću i optimizacija trajektorije stopala za biološki inspiriranog četveronožnog robota
(Hybrid Compliance Control and Foot Trajectory Optimization for a Bioinspired Quadruped robot)

Autori
Kočo, Edin

Vrsta, podvrsta i kategorija rada
Ocjenski radovi, doktorska disertacija

Fakultet
Fakultet elektrotehnike i računarstva

Mjesto
Zagreb

Datum
17.07

Godina
2017

Stranica
205

Mentor
Zdenko Kovacic

Ključne riječi
Quadruped robot, active compliance, variable passive compliance, hybrid compliance control, virtual springs, gait optimization, foot trajectory formulation

Sažetak
Modern quadruped robots are facing a real challenge to perform dynamic locomotion on rugged and unpredictable terrain. Unlike on flat terrain, when performing locomotion on rugged terrain very little can be assumed or predicted on robot’s behavior. In order to make our robots capable of navigating rough terrain, we can search for inspiration in nature by witnessing how animals preform fast and efficient locomotion on various terrain types. The nature teaches us how the soft interaction with the environment yields various beneficial characteristics in terms of stability, speed and efficiency which enables the biological systems to gracefully move on harsh terrain. Therefore we can conclude that compliance, either passive (formed by elastic tendons) or active (through muscle modulation), serves as important concern when designing, manufacturing and controlling legged robots. In this thesis we propose a hybrid compliance control system for a stiff-by-nature quadruped robot comprising active and variable passive compliance control parts and show how it can improve the performance of locomotion under moderate external disturbances. The observed robotic system integrates high gear ratio DC motors making the whole mechanism stiff and inconvenient for use for rugged terrain locomotion while subjected to unknown disturbances. To tackle this problem we have installed small and durable foot force sensors to sense the Ground Reaction Forces (GRF) in order to emulate compliant behavior using virtual springs. The robot leg design also integrates a mechanical implant allowing the robot to alter the passive compliance of the legs onthe-fly. The variable passive compliance ensures the filtering of sudden impacts during locomotion while the active compliance allows for lower bandwidth compliance control for locomotion purposes. Mathematical modeling and simulation analysis is conducted in order to identify the performance of the proposed system. We show how the derived compliance controllers can be used in synergy with foot trajectories in order to achieve arbitrary gaits. Finally we present a general framework for determining the parameters of foot trajectories through a multiobjective genetic algorithm optimization procedure based on maximization of locomotion speed and the minimization of consumed energy. Application of such framework leads to solutions that exhibit behaviors often seen in nature.

Izvorni jezik
Engleski

Znanstvena područja
Elektrotehnika, Temeljne tehničke znanosti

POVEZANOST RADA