Multi-segmented Adaptive Feet for Versatile Legged Locomotion in Natural Terrain

Most legged robots are built with leg structures from serially mounted links and actuators and are controlled through complex controllers and sensor feedback. In comparison, animals developed multi-segment legs, mechanical coupling between joints, and multi-segmented feet. They run agile over all terrains, arguably with simpler locomotion control. Here we focus on developing foot mechanisms that resist slipping and sinking also in natural terrain. We present first results of multi-segment feet mounted to a bird-inspired robot leg with multi-joint mechanical tendon coupling. Our one- and two-segment, mechanically adaptive feet show increased viable horizontal forces on multiple soft and hard substrates before starting to slip. We also observe that segmented feet reduce sinking on soft substrates compared to ball-feet and cylinder-feet. We report how multi-segmented feet provide a large range of viable centre of pressure points well suited for bipedal robots, but also for quadruped robots on slopes and natural terrain. Our results also offer a functional understanding of segmented feet in animals like ratite birds

Locomotor kinematics on sand versus vinyl flooring in the sidewinder rattlesnake Crotalus cerastes.

For terrestrial locomotion of animals and machines, physical characteristics of the substrate can strongly impact kinematics and performance. Snakes are an especially interesting system for studying substrate effects because their gait depends more on the environment than on their speed. We tested sidewinder rattlesnakes (Crotalus cerastes) on two surfaces: sand collected from their natural environment and vinyl tile flooring, an artificial surface often used to elicit sidewinding in laboratory settings. Of ten kinematic variables examined, two differed significantly between the substrates: the bodys waveform had an average of ∼17% longer wavelength on vinyl flooring (measured in body lengths), and snakes lifted their bodies an average of ∼40% higher on sand (measured in body lengths). Sidewinding may also differ among substrates in ways we did not measure (e.g. ground reaction forces and energetics), leaving open clear directions for future study

Diseño e Implementación del Sistema Electrónico y Comunicación para el Control un Robot Modular Tipo Serpiente

Este proyecto consiste en el desarrollo de un sistema electrónico para manipular a un robot serpiente de manera modular; se implementaron tarjetas electrónicas en una relación maestro-esclavas para el control articular de cada módulo mecánico. Estas tarjetas se componen de un DSPic30F4011, microcontrolador de 16 bits de Microchip que incorpora el modulo CAN, protocolo esencial para la comunicación entre tarjetas, salidas PWM para el control de motores, puertos análogos y digitales; como también un socket para conectarse a un dispositivo externo a través de la UART. El firmware ha sido escrito en MikroC Pro. Cada microcontrolador implementa una ecuación característica proveniente de las curvas de Hirose para generar un movimiento serpentino. Este movimiento se simuló usando ROS (Robotic Operating System) en Rviz y finalmente se implementó en el prototipo robot

Development The Electronic System Of Continues Modular Snake-Like-Robot

This project consists of the development of an electronic system to manipulate a snake like robot in a modular way. The electronic cards were implemented in a master-slave relationship for joint control of each mechanical module. These cards are composed of a DSPic30F4011, microchip 16-bit microcontroller that incorporates the CAN module, essential protocol for communication between cards, PWM outputs for motor control, analogue and digital ports; as well as a socket to connect to an external device through the UART. The firmware has been written in MikroC Pro. Each microcontroller implements the characteristic equation from the Hirose curves to generate a serpentine movement. These moves were simulated using ROS (Robotic Operating System in Rviz)

Optimizing the structure and movement of a robotic bat with biological kinematic synergies

In this article, we present methods to optimize the design and flight characteristics of a biologically inspired bat-like robot. In previous, work we have designed the topological structure for the wing kinematics of this robot; here we present methods to optimize the geometry of this structure, and to compute actuator trajectories such that its wingbeat pattern closely matches biological counterparts. Our approach is motivated by recent studies on biological bat flight that have shown that the salient aspects of wing motion can be accurately represented in a low-dimensional space. Although bats have over 40 degrees of freedom (DoFs), our robot possesses several biologically meaningful morphing specializations. We use principal component analysis (PCA) to characterize the two most dominant modes of biological bat flight kinematics, and we optimize our robot’s parametric kinematics to mimic these. The method yields a robot that is reduced from five degrees of actuation (DoAs) to just three, and that actively folds its wings within a wingbeat period. As a result of mimicking synergies, the robot produces an average net lift improvesment of 89% over the same robot when its wings cannot fold

Optimizing the structure and movement of a robotic bat with biological kinematic synergies

In this article, we present methods to optimize the design and flight characteristics of a biologically inspired bat-like robot. In previous, work we have designed the topological structure for the wing kinematics of this robot; here we present methods to optimize the geometry of this structure, and to compute actuator trajectories such that its wingbeat pattern closely matches biological counterparts. Our approach is motivated by recent studies on biological bat flight that have shown that the salient aspects of wing motion can be accurately represented in a low-dimensional space. Although bats have over 40 degrees of freedom (DoFs), our robot possesses several biologically meaningful morphing specializations. We use principal component analysis (PCA) to characterize the two most dominant modes of biological bat flight kinematics, and we optimize our robot’s parametric kinematics to mimic these. The method yields a robot that is reduced from five degrees of actuation (DoAs) to just three, and that actively folds its wings within a wingbeat period. As a result of mimicking synergies, the robot produces an average net lift improvesment of 89% over the same robot when its wings cannot fold