Bioinspired Jumping Locomotion for Miniature Robotics

In nature, many small animals use jumping locomotion to move in rough terrain. Compared to other modes of ground locomotion, jumping allows an animal to overcome obstacles that are relatively large compared to its size. In this thesis we outline the main design challenges that need to be addressed when building miniature jumping robots. We then present three novel robotic jumpers that solve those challenges and outperform existing similar jumping robots by one order of magnitude with regard to jumping height per size and weight. The robots presented in this thesis, called EPFL jumper v1, EPFL jumper v2 and EPFL jumper v3 have a weight between 7g and 14.3g and are able to jump up to 27 times their own size, with onboard energy and control. This high jumping performance is achieved by using the same mechanical design principles as found in jumping insects such as locusts or fleas. Further, we present a theoretical model which allows an evaluation whether the addition of wings could potentially allow a jumping robot to prolong its jumps. The results from the model and the experiments with a winged jumping robot indicate that for miniature robots, adding wings is not worthwhile when moving on ground. However, when jumping from an elevated starting position, adding wings can lead to longer distances traveled compared to jumping without wings. Moreover, it can reduce the kinetic energy on impact which needs to be absorbed by the robot structure. Based on this conclusion, we developed the EPFL jumpglider, the first miniature jumping and gliding robot that has been presented so far. It has a mass of 16.5g and is able to jump from elevated positions, perform steered gliding flight, land safely and locomote on ground with repetitive jumps1. ______________________________ 1See the collection of the accompanying videos at http://lis.epfl.ch/microglider/moviesAll.zi

Aerial additive building manufacturing: Three-dimensional printing of polymer structures using drones

This paper describes the first aerial additive building manufacturing system developed to create and repair civil engineering structures remotely using polymers extruded from unmanned aerial robots (drones). The structural potential of three commercially available expanding polyurethane foams of varying density (LD40, Reprocell 300 and Reprocell 500), and their feasibility for deposition using an autonomous flying dual-syringe device is described. Test specimens consisting of one and two layers, with horizontal and vertical interfaces, were mechanically tested both parallel and perpendicular to the direction of expansion. LD40 specimens exhibited ductile failure in flexural tests and provided evidence that the interfaces between layers were not necessarily regions of weaknesses. Hand-mixed specimens of Reprocell 500 possessed compressive strengths comparable to those of concrete and flexural strengths similar to those of the lower range of timber, though they exhibited brittle failure. There are challenges to be faced with matching the performance of hand-mixed specimens using an autonomous dual-syringe deposition device, primarily concerning the rheological properties of the material following extrusion. However, the device successfully imported and deposited two liquid components, of varying viscosity, and maintained correct mixing ratios. This work has demonstrated the structural and operational feasibility of polyurethane foam as a viable structural material for remote three-dimensional printing using drones

Evaluating Immersive Teleoperation Interfaces: Coordinating Robot Radiation Monitoring Tasks in Nuclear Facilities

We present a virtual reality (VR) teleoperation interface for a ground-based robot, featuring dense 3D environment reconstruction and a low latency video stream, with which operators can immersively explore remote environments. At the UK Atomic Energy Authority's (UKAEA) Remote Applications in Challenging Environments (RACE) facility, we applied the interface in a user study where trained robotics operators completed simulated nuclear monitoring and decommissioning style tasks to compare VR and traditional teleoperation interface designs. We found that operators in the VR condition took longer to complete the experiment, had reduced collisions, and rated the generated 3D map with higher importance when compared to non-VR operators. Additional physiological data suggested that VR operators had a lower objective cognitive workload during the experiment but also experienced increased physical demand. Overall the presented results show that VR interfaces may benefit work patterns in teleoperation tasks within the nuclear industry, but further work is needed to investigate how such interfaces can be integrated into real world decommissioning workflows

Public Policy Design and Implementation in Slovenia

Public policy design and implementation is a complex process, and so decision makers try to monitor all of the policy lifecycle stages in a particular policy domain. However, the question of coherent integration of various policy activities arises, including agenda-setting, ex-ante evaluation, formulation, decision-making, implementation, ex-post evaluation of individual policies, sector-specific ones, and even horizontal ones. Therefore, it is important to investigate and understand the reasons why an individual country, such as Slovenia, does not exploit all potential aspects of carrying out policy activities in a systematic and coherent manner. This article explores and analyzes Slovenian practice in policy design based on an in-depth empirical study among key public policyholders and decision makers. Furthermore, the authors identify the key success factors that facilitate or inhibit the development and progress of public policies, programs, and projects (PPPP) in Slovenia. The key findings indicate a particular lack of a professional policy unit to monitor the process holistically and the absence of ex-post evaluation. A need for a systemic solution in public policy design is established, which would merge different authorities’ efforts, epistemic communities, and the public in developing a structural multilevel model for good public governance

Deposition dynamics and analysis of polyurethane foam structure boundaries for Aerial Additive Manufacturing

Additive manufacturing in construction typically consists of ground-based platforms. Introducing aerial capabilities offers scope to create or repair structures in dangerous or elevated locations. The Aerial Additive Manufacturing (AAM) project has developed a pioneering approach using Unmanned Aerial Vehicles (UAV, ‘drones’) to deposit material during self-powered, autonomous, untethered flight. This study investigates high and low-density foams autonomously deposited as structural and insulation materials. Drilling resistance, mechanical, thermal and microscopy tests investigate density variation, interfacial integrity and thermal stability. Autonomous deposition is demonstrated using a flying UAV and robotic arm. Results reveal dense material at interfaces and directionally dependent cell expansion during foaming. Cured interfacial regions are vulnerable to loading parallel to interfaces but resistant to perpendicular loading. Mitigation of trajectory printing errors caused by UAV flight disturbance is demonstrated by a stabilising end effector, with trajectory errors ≤10 mm. AAM provides a significant development towards on-site automation in construction

Rotorigami: A rotary origami protective system for robotic rotorcraft

Applications of aerial robots are progressively expanding into complex urban and natural environments. Despite remarkable advancements in the field, robotic rotorcraft is still drastically limited by the environment in which they operate. Obstacle detection and avoidance systems have functionality limitations and substantially add to the computational complexity of the onboard equipment of flying vehicles. Furthermore, they often cannot identify difficult-to-detect obstacles such as windows and wires. Robustness to physical contact with the environment is essential to mitigate these limitations and continue mission completion. However, many current mechanical impact protection concepts are either not sufficiently effective or too heavy and cumbersome, severely limiting the flight time and the capability of flying in constrained and narrow spaces. Therefore, novel impact protection systems are needed to enable flying robots to navigate in confined or heavily cluttered environments easily, safely, and efficiently while minimizing the performance penalty caused by the protection method. Here, we report the development of a protection system for robotic rotorcraft consisting of a free-to-spin circular protector that is able to decouple impact yawing moments from the vehicle, combined with a cyclic origami impact cushion capable of reducing the peak impact force experienced by the vehicle. Experimental results using a sensor-equipped miniature quadrotor demonstrated the impact resilience effectiveness of the Rotary Origami Protective System (Rotorigami) for a variety of collision scenarios. We anticipate this work to be a starting point for the exploitation of origami structures in the passive or active impact protection of robotic vehicles