ON TRAVERSABILITY COST EVALUATION FROM PROPRIOCEPTIVE SENSING FOR A CRAWLING ROBOT

Traversability characteristics of the robot working environment are crucial in planning an efficient path for a robot operating in rough unstructured areas. In the literature, approaches to wheeled or tracked robots can be found, but a relatively little attention is given to walking multi-legged robots. Moreover, the existing approaches for terrain traversability assessment seem to be focused on gathering key features from a terrain model acquired from range data or camera image and only occasionally supplemented with proprioceptive sensing that expresses the interaction of the robot with the terrain. This paper addresses the problem of traversability cost evaluation based on proprioceptive sensing for a hexapod walking robot while optimizing different criteria. We present several methods of evaluating the robot-terrain interaction that can be used as a cost function for an assessment of the robot motion that can be utilized in high-level path-planning algorithms

ON EVALUATION OF MOTION GAITS ENERGY EFFICIENCY WITH A HEXAPOD CRAWLING ROBOT

In this work, we are concerning the problem of energy efficient locomotion of a hexapod crawling robot. We are emphasizing a practical verification and deployment on a real walking robot to evaluate relations between the energy consumption, motion speed, and terrain type with a particular motion gait. The tripod, tetrapod, and pentapod motion gaits are considered in the presented evaluation report

Locomotion Control of Hexapod Walking Robot with Four Degrees of Freedom per Leg

V této práci představujeme nového šestinohého robota jménem HAntR, kterého jsme vytvořili dle potřeb Laboratoře výpočetní robotiky Centra umělé inteligence fakulty Elektrotechnické Českého vysokého učení technického v Praze. Jeho hlavním účelem jest vylepšit schopnosti pohybu v těžkém terénu původního robotu přidáním čtvrtého stupně volnosti každé noze. Na základě nově navržené nohy jsme také přepracovali celé tělo robotu tak, aby splnilo i další požadavky, jako například menší rozměry, či možnost osazení alespoň šesti Lithium-Iontovými monočlánky. V práci pečlivě popisujeme motivace a úvahy, které nás k výslednému návrhu vedly. Uvádíme řešení přímé i inverzní kinematické úlohy řešené pomocí podmínky na ideální orientaci konce nohy a uvažující i důležité kinematické singularity. Navržený robot byl vyzkoušen v několika experimentech, při kterých byl použit námi navržený řídicí systém napsaný v jazyce C++. Ukázalo se, že HAntR vydrží díky zvýšené energetické hustotě a lepšímu rozkladu sil v končetinách autonomně fungovat přes hodinu. Robot je také schopen jít rychlostí až 0.42m/s, což předčí mnohé srovnatelné roboty. Při experimentu, kdy robot stál na nakloněné rovině, bylo prokázáno zlepšení oproti předchozímu robotu. A také jsme dle pokynů této práce potvrdili, že i HAntR je schopen adaptivní chůze spoléhající pouze na poziční zpětnou vazbu.In this thesis a novel six-legged robot called HAntR is presented. The robot was developed according to needs of the Robotics Laboratory, at the Artificial Intelligent Center, Faculty of Electrical Engineering, Czech Technical University in Prague. Its main purpose is enhancing rough-terrain movement capabilities by upgrading a former design by adding fourth degree of freedom to each leg. We also revised robot torso to fit new leg design and incorporate other requirements such as smaller dimensions with space for at least six Lithium-Ion cells. We thoroughly describe motivations and considerations that led us to the presented particular solution. Further, the solutions of forward and inverse kinematic tasks with partial orientation constraint and important singularities avoidance are presented. The proposed design has been evaluated in several experimental deployments, which utilised developed software controller written in C++. Endurance tests showed, that HAntR is able to remotely operate for over an hour thanks to increased energy density. Maximal speed test resulted to 0.42m/s during tripod gait, which outpaces most of the comparable robotic platforms. Experiment where HAntR stood on platform with varying inclination showed qualitative improvement against former robot. Finally, in accord with the thesis assignment, we proved that HAntR is able to perform walking with adaptive gait using positional feedback only

Reflex assisted walking for a hexapod robot

Abstract: This paper describes the performance of a hexapod robot that uses low level leg reflexes to aid in walking over uneven terrain, and is currently being developed at the University of Johannesburg. The goal of this research is a robot able to deploy in both the inspection and search and rescue roles, within an underground mine environment. The robot has six legs with three degrees of freedom per leg, and is equipped with a two degree of freedom arm with a sensor payload attached to a pan-tilt system. Throughout the development of this new robot the Design Science Research Methodology was used to guide the decision making process. This paper presents an overview of the robot, including the control architecture, and the testing conducted to verify the robot’s performance when walking over a laboratory test field

Simplifying robotic locomotion by escaping traps via an active tail

Legged systems offer the ability to negotiate and climb heterogeneous terrains, more so than their wheeled counterparts \cite{freedberg_2012}. However, in certain complex environments, these systems are susceptible to failure conditions. These scenarios are caused by the interplay between the locomotor's kinematic state and the local terrain configuration, thus making them challenging to predict and overcome. These failures can cause catastrophic damage to the system and thus, methods to avoid such scenarios have been developed. These strategies typically take the form of environmental sensing or passive mechanical elements that adapt to the terrain. Such methods come at an increased control and mechanical design complexity for the system, often still being susceptible to imperceptible hazards. In this study, we investigated whether a tail could serve to offload this complexity by acting as a mechanism to generate new terradynamic interactions and mitigate failure via substrate contact. To do so, we developed a quadrupedal C-leg robophysical model (length and width = 27 cm, limb radius = 8 cm) capable of walking over rough terrain with an attachable actuated tail (length = 17 cm). We investigated three distinct tail strategies: static pose, periodic tapping, and load-triggered (power) tapping, while varying the angle of the tail relative to the body. We challenged the system to traverse a terrain (length = 160 cm, width = 80 cm) of randomized blocks (length and width = 10 cm, height = 0 to 12 cm) whose dimensions were scaled to the robot. Over this terrain, the robot exhibited trapping failures independent of gait pattern. Using the tail, the robot could free itself from trapping with a probability of 0 to 0.5, with the load-driven behaviors having comparable performance to low frequency periodic tapping across all tested tail angles. Along with increasing this likelihood of freeing, the robot displayed a longer survival distance over the rough terrain with these tail behaviors. In summary, we present the beginning of a framework that leverages mechanics via tail-ground interactions to offload limb control and design complexity to mitigate failure and improve legged system performance in heterogeneous environments.M.S

ON CONSTRUCTION OF A RELIABLE GROUND TRUTH FOR EVALUATION OF VISUAL SLAM ALGORITHMS

In this work we are concerning the problem of localization accuracy evaluation of visual-based Simultaneous Localization and Mapping (SLAM) techniques. Quantitative evaluation of the SLAM algorithm performance is usually done using the established metrics of Relative pose error and Absolute trajectory error which require a precise and reliable ground truth. Such a ground truth is usually hard to obtain, while it requires an expensive external localization system. In this work we are proposing to use the SLAM algorithm itself to construct a reliable ground-truth by offline frame-by-frame processing. The generated ground-truth is suitable for evaluation of different SLAM systems, as well as for tuning the parametrization of the on-line SLAM. The presented practical experimental results indicate the feasibility of the proposed approach

Overcoming barriers and increasing independence: service robots for elderly and disabled people

This paper discusses the potential for service robots to overcome barriers and increase independence of elderly and disabled people. It includes a brief overview of the existing uses of service robots by disabled and elderly people and advances in technology which will make new uses possible and provides suggestions for some of these new applications. The paper also considers the design and other conditions to be met for user acceptance. It also discusses the complementarity of assistive service robots and personal assistance and considers the types of applications and users for which service robots are and are not suitable

Automation and Robotics: Latest Achievements, Challenges and Prospects

This SI presents the latest achievements, challenges and prospects for drives, actuators, sensors, controls and robot navigation with reverse validation and applications in the field of industrial automation and robotics. Automation, supported by robotics, can effectively speed up and improve production. The industrialization of complex mechatronic components, especially robots, requires a large number of special processes already in the pre-production stage provided by modelling and simulation. This area of research from the very beginning includes drives, process technology, actuators, sensors, control systems and all connections in mechatronic systems. Automation and robotics form broad-spectrum areas of research, which are tightly interconnected. To reduce costs in the pre-production stage and to reduce production preparation time, it is necessary to solve complex tasks in the form of simulation with the use of standard software products and new technologies that allow, for example, machine vision and other imaging tools to examine new physical contexts, dependencies and connections

The development of fire detection robot

Bu tez çalışmasının amacı; özellikle endüstriyel alanlarda, erken yangın algılamada kullanılacak bir yangın algılama robotu tasarlamak ve imal etmektir. Bu robot; önceden belirlenen sanal güzergâh üzerinde engel algılama fonksiyonuyla ve yeniden programlanabilir hareket ünitesiyle devriye gezebilecek ve yangın kaynağını tespit edebilmek için ortam taraması yapabilecek şekilde tasarlanmış ve imal edilmiştir. Sistem; hareket planlama ünitesine tanımlanan programlar ile değişken devriye güzergâhlarını takip edebilme yeteneğine sahiptir. Robotun tasarım ve uygulama süreçleri şu şekildedir; mekanik sistemin tasarımı ve geliştirilmesi, elektronik sistemin tasarımı ve geliştirilmesi ve gerekli yazılımların hazırlanmasıdır. Mekanik sistemin tasarım ve geliştirilme sürecinde; taslak çizimleri, ölçülendirmeler ve üç boyutlu modelleme için bilgisayar destekli tasarım ve katı modelleme programları kullanılmıştır. Robotun taşıyıcı gövdesi; ucuz, sağlam ve kolay işlenebilir malzemeler olan ahşap ve sert plastik köpük kullanılarak imal edilmiştir. Robot sürüş sisteminde diferansiyel metot kullanılmıştır. Yarı otomatik robot dört adet fırçalı doğru akım motoru ile çalışmaktadır. Elektronik sistemin tasarımı ve geliştirilmesi sürecinde; hazır kart almak yerine ihtiyaca uygun elektronik veri kazanım ve kontrol devreleri tasarlanıp üretilmiştir. Bu devrelerin şematik diyagramı ve baskı devresi Proteus elektronik tasarım programı kullanılarak hazırlanmıştır. Bu devreler; motor hareketlerini kontrol etmekte ve dizüstü bilgisayar ile algılama üniteleri arasında bir köprü kurmakta kullanılmıştır. Yazılımların hazırlanma sürecinde; engel algılamada ve güzergâh takibinde kullanılacak akıllı yazılımlar geliştirilmiştir. Ayrıca daha güvenilir yangın algılama sağlamak için; çoklu sensör algılama ve değerlendirme algoritması geliştirilmiştir. Bu tezin sonucunda; özellikle endüstriyel alanlarda kullanılabilecek, çeşitli fonksiyonlara sahip bir yangın algılama robotu tasarlanıp imal edilmiştir. Yapılan testlerle; sistemin en fazla 100 cm mesafedeki yangını, robot 0,5 m/s hızla ilerlerken tespit edebildiği sonucuna varılmıştır.The aim of this thesis is to design and manufacture a fire detection robot that especially operates in industrial areas for fire inspection and early detection. Robot is designed and implemented to track prescribed paths with obstacle avoidance function through obstacle avoidance and motion planning units and to scan the environment in order to detect fire source using fire detection unit. Robot is able to track patrolling routes using virtual lines that defined to the motion planning unit. The design and implementation processes of the robot are as follow; the design and the development of mechanical, electronic systems and software. The design and the development of mechanical system; for the sketch drawings, dimensioning and solid state modeling of the robot, computer aided design and solid modelling computer programs were used. The carrier board of the robot is produced using wooden material and rigid plastic foam which are cheap, strong enough and easy to manufacture. Differential steering method is selected for semi-autonomous robot driving system and it is powered by four brushed DC (direct current) motors. The design and the development of electronic system; electronic circuits were designed and produced, instead of buying a commercial card. Both schematic diagrams and circuits of the data acquisition and control circuits are designed using Proteus electronic design program. These circuits are used to control the motion of the motors and establish a data flow between the laptop and the other peripheral sensing components. Software development; intelligent algorithms for obstacle avoidance and path tracking have been developed. A sensor data fusion algorithm for the sensors was also developed to get more reliable fire detection information. In conclusion; a fire inspection and detection robot with various functions to especially can be used in industrial areas was designed and manufactured. The functions of the robot were tested. It can be concluded that system is able to detect the fire source maximum 100 cm distance away while robot is moving with 0.5 m/s forward speed