On the Hardware Feasibility of Nonlinear Trajectory Optimization for Legged Locomotion based on a Simplified Dynamics

Simplified models are useful to increase the computational efficiency of a motion planning algorithm, but their lack of accuracy have to be managed. We propose two feasibility constraints to be included in a Single Rigid Body Dynamics-based trajectory optimizer in order to obtain robust motions in challenging terrain. The first one finds an approximate relationship between joint-torque limits and admissible contact forces, without requiring the joint positions. The second one proposes a leg model to prevent leg collision with the environment. Such constraints have been included in a simplified nonlinear non-convex trajectory optimization problem. We demonstrate the feasibility of the resulting motion plans both in simulation and on the Hydraulically actuated Quadruped (HyQ) robot, considering experiments on an irregular terrain

PTA-DESTINATION: a decision support system to ensure human and environmental protection

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Design of a Container Mechanism for Trash Collection on Quadruped Robots

This paper presents the design of a novel container mechanism, tailored for autonomous robotic trash collection, specifically designed for mounting on quadruped robots. The commercial AlienGo and Z1 Unitree robotic arm, along with the container developed in this project, have been integrated to form a robotic system capable of effectively navigating and cleaning environments characterized by rough terrain, such as beaches, stairs, and rocks. The proposed container enables seamless interfacing with the robotic arm, facilitating efficient trash storage and autonomous unloading operations. Furthermore, the container has been engineered to be lightweight, complying with the quadruped’s payload constraints, yet it possesses robustness against the potential damage encountered in real-world operations. The design process started from scratch, with multiple conceptual designs being evaluated. Subsequently, comprehensive mechanical design and simulations were conducted to develop a mechanism that meets the project’s requirements and objectives efficiently. The construction and real-world testing of the mechanism successfully confirmed its functionality and integration within the robotic system. The final container mechanism proposed in this paper represents an innovative subsystem, equipped with essential features for integration with the quadruped robot and the robotic arm