Development and applications of quadruped robots: from rigid-body model to flexible body

Quadruped robots represent a rapidly developing technology with significant potential applications. These robots offer a notable advantage over wheeled robotic vehicles due to their ability to navigate obstacles, enhancing their versatility and making them a subject of intensive development aimed at increasing their adaptability, reducing costs, and broadening accessibility. Potential applications extend beyond industrial and military uses, including hazardous human activities such as inspecting unstable buildings, providing support during disasters, and exploring contaminated areas. Despite these potential applications, widespread adoption remains limited due to high costs and developmental challenges. Current quadruped robots exhibit limited versatility and greater instability compared to wheeled robots, which benefit from simpler designs and more established technologies. This thesis initially reviews the current modeling techniques for quadruped robots, highlighting their strengths and limitations. It then surveys key studies and achievements in the field to date. The research conducted aims to address existing gaps and uncertainties in the literature, focusing on enhancing the versatility of quadruped robots through a novel gait optimization method for highly dynamic systems. This involves evaluating the inertial and Coriolis effects on leg movements, ensuring a complete solution to the equations of motion. The core objective of the doctoral research is to refine models, techniques, and strategies to identify optimal motion conditions for quadruped robots. While much of the study centers on rigid-body kinematic chains, it also includes preliminary research on gait optimization using a flexible robotic body within the quadruped system. The main findings from these studies are presented in the latter part of the thesis.