Cable-driven parallel robot for curtain wall module installation

A cable-driven parallel robot (CDPR) was developed for the installation of curtain wall modules (CWM). The research addressed the question of whether the CDPR was capable installing CWMs with sufficient accuracy while being competitive compared to conventional manual methods. In order to develop and test such a system, a conceptual framework that consisted of three sub-systems was defined. The tests, carried out in two close-to-real demonstration buildings, revealed an absolute accuracy of the CWM installation of 4 to 23 mm. The working time for installing a CWM was reduced to 0.51 h. The results also show that the system is competitive for a workspace greater than 96 m2 compared to conventional manual methods. However, improvements such as reducing the hours for setting up the CDPR on the one hand and achieving a faster and more robust MEE on the other hand will be still necessary in the future.This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 73251

Long-Term Urban Vehicle Localization Using Pole Landmarks Extracted from 3-D Lidar Scans

Due to their ubiquity and long-term stability, pole-like objects are well suited to serve as landmarks for vehicle localization in urban environments. In this work, we present a complete mapping and long-term localization system based on pole landmarks extracted from 3-D lidar data. Our approach features a novel pole detector, a mapping module, and an online localization module, each of which are described in detail, and for which we provide an open-source implementation at www.github.com/acschaefer/polex. In extensive experiments, we demonstrate that our method improves on the state of the art with respect to long-term reliability and accuracy: First, we prove reliability by tasking the system with localizing a mobile robot over the course of 15~months in an urban area based on an initial map, confronting it with constantly varying routes, differing weather conditions, seasonal changes, and construction sites. Second, we show that the proposed approach clearly outperforms a recently published method in terms of accuracy.Comment: 9 page

Initial Stages of Implementation

Multirotors are used in many applications in the present. For some of these applications the capability of the vehicle to perform autonomous missions is a key element. The work for this thesis consists on the initial stages of a multirotor precision landing system implementation. Two commercially available and cheap systems were proposed so that they can be used for commercial purposes. One of the systems (Marvelmind) works by triangulating distances obtained by the relation between the speed of sound and the delay on a transmitted ultrasound (time of flight). The other system (IR-LOCK) works based on a camera (infrared sensible) that detects a target (that emits infrared light) and estimates its relative position. After the initial setup for each system, problems were identified and solutions implemented accordingly. With the Marvelmind system, the autopilot is able to identify its position but is unstable when performing a hover flight and as a result, an autonomous landing is not possible. With the IR-LOCK system, the vehicle is capable of performing autonomous precise landings.Os multirotores são utilizados em imensas aplicações actualmente. Para algumas destas aplicações a capacidade de o veículo efectuar missões de forma autónoma é um ponto-chave. O trabalho para esta disseratção consiste nas etapas iniciais da implementação de um sistema de aterragem de precisão para multirotores. Foram escolhidos dois sistemas cormercialmente disponíveis e baratos para que possam ser utilizados para fins comerciais. Um dos sistemas (Marvelmind) funciona através da triangulação de distâncias obtidas pela relação entre a velocidade do som e o tempo de transmissão de ultrassons (tempo de voo). O outro sistema (IR-LOCK) implementado funciona com base numa câmara (sensível à radiação infravermelha) que deteta um alvo (emissor de radiação infravermelha) e estima a sua posição relativa. Após a configuração inicial de cada sistema, foram identificados problemas e implementadas soluções apropriadas. Com o sistema Marvelmind, o piloto automático é capaz de identificar a sua posição mas é instável ao realizar um voo pairado e por conseguinte, uma aterragem de forma autónoma não é possível. Com o sistema IR-LOCK, o veículo é capaz de executar aterragens autónomas precisas

Aerobrake assembly with minimum Space Station accommodation

The minimum Space Station Freedom accommodations required for initial assembly, repair, and refurbishment of the Lunar aerobrake were investigated. Baseline Space Station Freedom support services were assumed, as well as reasonable earth-to-orbit possibilities. A set of three aerobrake configurations representative of the major themes in aerobraking were developed. Structural assembly concepts, along with on-orbit assembly and refurbishment scenarios were created. The scenarios were exercised to identify required Space Station Freedom accommodations. Finally, important areas for follow-on study were also identified