The Problem of Adhesion Methods and Locomotion Mechanism Development for Wall-Climbing Robots

This review considers a problem in the development of mobile robot adhesion methods with vertical surfaces and the appropriate locomotion mechanism design. The evolution of adhesion methods for wall-climbing robots (based on friction, magnetic forces, air pressure, electrostatic adhesion, molecular forces, rheological properties of fluids and their combinations) and their locomotion principles (wheeled, tracked, walking, sliding framed and hybrid) is studied. Wall-climbing robots are classified according to the applications, adhesion methods and locomotion mechanisms. The advantages and disadvantages of various adhesion methods and locomotion mechanisms are analyzed in terms of mobility, noiselessness, autonomy and energy efficiency. Focus is placed on the physical and technical aspects of the adhesion methods and the possibility of combining adhesion and locomotion methods

TERMES: An Autonomous Robotic System for Three-Dimensional Collective Construction

Collective construction is the research area in which autonomous multi-robot systems build structures according to user specifications. Here we present a hardware system and high-level control scheme for autonomous construction of 3D structures under conditions of gravity. The hardware comprises a mobile robot and specialized passive blocks; the robot is able to manipulate blocks to build desired structures, and can maneuver on these structures as well as in unstructured environments. We describe and evaluate the robot's key capabilities of climbing, navigation, and manipulation, and demonstrate its ability to perform complex tasks that combine these capabilities by having it autonomously build a ten-block staircase taller than itself. In addition, we outline a simple decentralized control algorithm by which multiple simultaneously active robots could autonomously build user-specified structures, working from a high-level description as input.Engineering and Applied Science

Grasping, Perching, And Visual Servoing For Micro Aerial Vehicles

Micro Aerial Vehicles (MAVs) have seen a dramatic growth in the consumer market because of their ability to provide new vantage points for aerial photography and videography. However, there is little consideration for physical interaction with the environment surrounding them. Onboard manipulators are absent, and onboard perception, if existent, is used to avoid obstacles and maintain a minimum distance from them. There are many applications, however, which would benefit greatly from aerial manipulation or flight in close proximity to structures. This work is focused on facilitating these types of close interactions between quadrotors and surrounding objects. We first explore high-speed grasping, enabling a quadrotor to quickly grasp an object while moving at a high relative velocity. Next, we discuss planning and control strategies, empowering a quadrotor to perch on vertical surfaces using a downward-facing gripper. Then, we demonstrate that such interactions can be achieved using only onboard sensors by incorporating vision-based control and vision-based planning. In particular, we show how a quadrotor can use a single camera and an Inertial Measurement Unit (IMU) to perch on a cylinder. Finally, we generalize our approach to consider objects in motion, and we present relative pose estimation and planning, enabling tracking of a moving sphere using only an onboard camera and IMU

Bio-Inspired Robotics

Modern robotic technologies have enabled robots to operate in a variety of unstructured and dynamically-changing environments, in addition to traditional structured environments. Robots have, thus, become an important element in our everyday lives. One key approach to develop such intelligent and autonomous robots is to draw inspiration from biological systems. Biological structure, mechanisms, and underlying principles have the potential to provide new ideas to support the improvement of conventional robotic designs and control. Such biological principles usually originate from animal or even plant models, for robots, which can sense, think, walk, swim, crawl, jump or even fly. Thus, it is believed that these bio-inspired methods are becoming increasingly important in the face of complex applications. Bio-inspired robotics is leading to the study of innovative structures and computing with sensory–motor coordination and learning to achieve intelligence, flexibility, stability, and adaptation for emergent robotic applications, such as manipulation, learning, and control. This Special Issue invites original papers of innovative ideas and concepts, new discoveries and improvements, and novel applications and business models relevant to the selected topics of ``Bio-Inspired Robotics''. Bio-Inspired Robotics is a broad topic and an ongoing expanding field. This Special Issue collates 30 papers that address some of the important challenges and opportunities in this broad and expanding field

Prototyping for Research and Industry

In this thesis we want to present some of the activities carried out during the PhD studies held at the PhD School "L. da Vinci" in the period from January 2012 to December 2014. The activities were held in the fields of robotics and mechanical engineering, and the main theme was the prototyping of new concepts, as well as the activity of conceptual design in its different phases, from generation of the idea, to the realization and testing of prototypes. The conceptual design phase is of fundamental importance to structure the process of generation of new ideas. Sometimes it is a process that is carried out unconsciously by the inventor. Providing a tool that allows to guide him in the various stages of idea generation can lead to advantages that let the inventor to explore areas from which take inspiration, which otherwise would not have been taken into account. An aspect of fundamental importance in the development of new prototypes is a process that goes in the opposite direction of the idea generation phase. Initially the conceptual design tends to provide tools to generate as many ideas as possible, but at some point there is the need to select a limited number of cases to investigate. Through the selection phase, which can be structured at levels more or less structured, and more or less qualitative/quantitative, the inventor tends to identify, case by case, which are the ideas in which is worth investing time and resources, before moving to the following stages. Prototyping, as well as its previous phase, now commonly called pretotyping, are mandatory steps for those who want to develop any new idea. The success of the final product or service may depend from the analysis of the pretotype first, and of the prototype later, since it allows to detect limits and possible improvements of the concept before moving to the final implementation phase

Design and Development of a Mobile Climbing Robot for Wind Turbine Inspection

Wind turbines (WT) have become an essential renewable energy source as the contribution of WT farms has reached megawatts scale. However, wind turbine blades (WTB) are subjected to failure due to many loading effects such as aerodynamic, gravity and centrifugal loads and operation in harsh environments such as ultraviolet (UV) radiation, ice, hail, temperature variation, dirt, and salt. As a result, the blades suffer different types of damage. Consequently, a periodic inspection process is required to detect and repair defects before a catastrophic failure happens. This thesis presents a literature review of wall climbing robots to identify the most appropriate locomotion and adhesion method to use for a WT climbing machine that can take a large payload of non-destructive testing (NDT) sensors up to a blade and deploy them with scanning arms. A review of wind turbine blade construction, various loading effects on blades and types of damage in blades is followed by a review of the NDT techniques used for inspecting WTB. The above review determines the design requirements to achieve the aim of the current research which is to design a low-cost and reliable mobile robot which will be able to climb the WT tower and subsequently scan the blade surface to perform the inspection using various sensors to identify and classify damages. This robot system should be able to access all the critical areas of the blade structure in a stable and secure way. It should be stable enough to allow the various test sensors to scan the blade structure in the shortest possible time. The thesis describes the development of a tower climbing robot that uses magnetic adhesion to adhere to the WT. As a preliminary study, a simulation model is developed using COMSOL Multiphysics to simulate the magnetic adhesion force while climbing the tower. A test rig is designed and fabricated to measure the magnetic adhesion force experimentally to validate the simulation model. The response surface methodology (RSM) using Box-Behnken design (BBD) is used to design and perform experiments to optimise different independent variables i.e. air gap, the distance between magnets in an array and backplate (yoke) thickness that affect the magnetic adhesion force. A scaled-down prototype magnetic adhesion climbing robot has been designed and constructed for wind turbine blade inspection. The robot is 0.29 m long with two 1.0 m long arms, weighs 10.0 kg and can carry a maximum 2.0 kg payload of NDT sensors. Optimum design of a magnetic adhesion mechanism has been developed for the climbing robot prototype that maximises the magnetic adhesion force. The robot is equipped with two arms that can be extended by one meter to come close to the blade for inspection. Each arm is equipped with a gripper that can hold an inspection tool of weight up to one kilogram. A scaled-down wind turbine has been modelled using SolidWorks and a portion of it constructed to experimentally test the scaled-down climbing robot. To scale up the robot prototype for operation on a normal sized wind turbine, a 100 m tall wind turbine with three 76 m long blades has been modelled and the prototype robot scaled up based on these dimensions. The scaled-up robot is 3.0 m long, weighs 1135 kg and has two 10 m long arms. Static stress analysis and flow simulation have been carried out to check the durability of the scaled-up robot while climbing the wind turbine tower. The procedure for scaling up the adhesion mechanism to achieve equilibrium of the robot has been introduced based on the reaction force concluded from the static stress and flow simulation study. As a result, the maximum payload that each arm can carry has been calculated for both the scaled-down prototype (1 kg) and the scaled-up design (50 kg). This concludes the utility and robustness of the wall climbing robot as a robotic solution for wind turbine blade inspection

Advanced Mobile Robotics: Volume 3

Mobile robotics is a challenging field with great potential. It covers disciplines including electrical engineering, mechanical engineering, computer science, cognitive science, and social science. It is essential to the design of automated robots, in combination with artificial intelligence, vision, and sensor technologies. Mobile robots are widely used for surveillance, guidance, transportation and entertainment tasks, as well as medical applications. This Special Issue intends to concentrate on recent developments concerning mobile robots and the research surrounding them to enhance studies on the fundamental problems observed in the robots. Various multidisciplinary approaches and integrative contributions including navigation, learning and adaptation, networked system, biologically inspired robots and cognitive methods are welcome contributions to this Special Issue, both from a research and an application perspective

Development, Control, and Empirical Evaluation of the Six-Legged Robot SpaceClimber Designed for Extraterrestrial Crater Exploration

In the recent past, mobile robots played an important role in the field of extraterrestrial surface exploration. Unfortunately, the currently available space exploration rovers do not provide the necessary mobility to reach scientifically interesting places in rough and steep terrain like boulder fields and craters. Multi-legged robots have proven to be a good solution to provide high mobility in unstructured environments. However, space missions place high demands on the system design, control, and performance which are hard to fulfill with such kinematically complex systems. This thesis focuses on the development, control, and evaluation of a six-legged robot for the purpose of lunar crater exploration considering the requirements arising from the envisaged mission scenario. The performance of the developed system is evaluated and optimized based on empirical data acquired in significant and reproducible experiments performed in a laboratory environment in order to show thecapability of the system to perform such a task and to provide a basis for the comparability with other mobile robotic solutions