Patrick Labenda

Snake‐like, tracked, mobile robot with active flippers for urban search‐and‐rescue tasks

Purpose – After a building collapse, people buried alive have to be localized and rescued. This requires the damage sites inspection and surveillance. These tasks are dangerous and challenging due to the areas hard‐to‐reach and hazardous environment. The damage site cannot be actively entered but must be inspected from a safe distance. In this context, mobile robots gain in importance as they can be operated semi‐autonomously or remote‐controlled without exposing the first responders to the risk. The purpose of this paper is to introduce a novel robot.Design/methodology/approach – The novel robot introduced in this paper has a snake‐like build‐up, uses tracks and active flippers for locomotion and negotiates completely structured as well as extremely unstructured and rough terrain. The systems slender, segmented and modular structure is actively articulated by the use of overall 30 degrees‐of‐freedom, which allow the robots flexible adaptation to a given terrain. System‐terrain‐interaction is detected...

Study of efficiency of USAR operations with assistive technologies

Abstract This paper presents a study on efficiency of Urban Search and Rescue (USAR) missions that has been carried out within the framework of the German research project I-LOV. After three years of development, first field tests have been carried out in 2011 by professionals such as the Rapid Deployment Unit for Salvage Operations Abroad (SEEBA). We present results from evaluating search teams in simulated USAR scenarios equipped with newly developed technical search means and digital data input terminals developed in the I-LOV project. In particular, USAR missions assisted by the ‘bioradar’, a radar system for the detection of humanoid movements, a semi-active video probe of more than 10m length for rubble pile exploration, a snake-like rescue robot, and the decision support system FRIEDAA were evaluated and compared with conventional USAR missions. Results of this evaluation indicate that the developed technologies represent an advantage for USAR missions, which are discussed in this paper.

A Methodology for the Development, Production, and Validation of R-Phase Actuators

The R-phase transformation has interesting features with potential for applications that need a small temperature hysteresis and good dynamic behavior, such as thermostatic valves. The aim of this article is to show the development, production, and validation process of different R-phase shape memory alloy (SMA) actuators, starting with a semi-finished wire and concluding with a finalized R-phase spring actuator. This study focuses mainly on the calculation, the thermomechanical treatment, and experimental validation of the designed actuators. The first section of this article presents a mathematical dimensioning tool for different R-phase actuators, especially for extension SMA springs. The second part shows specific parameters on the R-phase transformation during thermomechanical treatment. The parameters Ni-content and annealing temperature are being varied to achieve different transformation behavior of the R-phase. The third section relates to the production process of calculated SMA spring actuators based on the R-phase transformation. In the fourth and last section of the article, the performance of selected actuators will be characterized in functional tests, and the results will be compared with the calculated results of the mathematical model.

Traditional and project- and team-based education in mechatronic and robotic systems design

Basically, education in engineering design has to focus, on the one hand, on impartment of theoretical knowledge as well as, on the other hand, on gaining practical experiences. But additionally, teaching and education has to adequately cope with the fact that technical products and systems are becoming increasingly multidisciplinary. Best examples are mechatronic and robotic systems. Such products can effectively be developed only by a team of engineers and designers. The involved team members mostly have different background, knowledge and experiences. Consequently, already during their education students have to be adequately prepared for team-based work to be able to understand, communicate and work with the other team members. Hence, distinct team and soft skills gain significant importance. This paper reports on our educational concept combining traditional and advanced methods to gain, on the one hand, systems- and subject-related as well as, on the other hand, practice-related, personal and social competency. At its core are small-scaled design-and-build projects standing out due to their integrated approach.

Controlled Maneuverability of an Articulated Tracked Mobile Robot

Considerable potentials with regard to mobility in unstructured environment offer actively articulated mobile robots equipped with powered wheels or tracks. These potentials are obvious when dealing with a system’s trafficability and terrainability. However, maneuverability and steerability of articulated mobile robots are challenging. This is due to the fact that these robots represent a form of truck-trailer systems leading to interactions and influences between the individual vehicles resulting in significant problems like e.g. off-tracking with regard to a given path. Further on, when dealing with a mobile robot’s maneuverability there are only few scientific contributions covering articulated vehicles with actively powered trailers using tracks as propulsive elements. The described systems differ significantly with regard to their configuration with respect to the multi-redundant mobile robot in this work. To investigate the maneuverability of articulated tracked mobile robots a demonstrator has been developed. It is built up out of three identical modules which are connected with each other in a rowby means of a rotational and a translational degree-of-freedom. Each module has two tracks which can be powered independently. Overall, the system has got ten degrees-of-freedom whereas six of them are active and four passive. The developed demonstrator has been used for investigations dealing with maneuverability and steerability as well as modularization of the system’s control architecture. The paper summarizes the development of the mobile robot, its feedback control strategy as well as the tests carried out. The achieved results show a satisfying performance with regard to the implemented control strategy and the system’s maneuverability.Copyright

Wheeled, Kinematically Redundant Locomotion System for Mobility-Oriented Research and Experimentation

Mobile robots for inspection and surveillance of hard-to-reach and hazardous areas e.g. resulting from a building collapse in the course of a natural or man-made catastrophe have to possess enhanced rough terrain mobility capabilities. First, they must be able to navigate through a given environment and to avoid insurmountable obstacles. Second, they must have the ability to traverse different forms of ground without getting immobilized by a loss of traction. Third, they must be able to negotiate a wide spectrum of obstacles including e.g. wide gaps and high steps. These abilities can be described as a mobile robots performance indices “maneuverability”, “trafficability” and “terrainability”. As a consequence, mobile robot concepts for disaster control and search-and-rescue tasks always have to be developed and evaluated with regard to these performance indices. In principle, considerable potentials with regard to mobility in unstructured and rough environments offer kinematically redundant locomotion systems equipped with powered wheels or tracks which are inspired by their biological archetype snake. These potentials are based on the systems’ snake-like; modular design as well as their given kinematic redundancy. Due to their slender, modular and flexible design the systems are basically able to travel and maneuver through noticeable narrow passes and tunnels. Further on, their kinematic redundancy can be used for a purposeful posture and terrain adaptation to safeguard traction and the system’s trafficability, respectively. Finally, the systems’ modular and articulated design, both, can be used to achieve an outstanding terrainability and to be able to negotiate remarkable obstacles. The described and expected potentials of kinematically redundant locomotion systems have to be investigated in detail as well as evaluated in practice. To be able to do so, a demonstrator has been developed and implemented for intense mobility-oriented research and experimentation. The mobile robot and first experimental results are described in the paper at hand. The system stands out especially due to an innovative sensory for slip and contact force detection.Copyright

Shared control system to safeguard mobility of wheeled, actively articulated truck-trailer vehicles on structured and rough terrain

For transportation tasks predominantly wheeled vehicles are used. This is due to a wheels easy construction, its simple actuation and control implementation as well as the fact that no energy is wasted to overcome gravitational effects. But wheeled vehicles are best suited for a use on prepared terrain and surfaces. Their mobility on unstructured and rough terrain is significantly limited. These limits can be overcome by the integration of active articulations which enable a vehicle systems reconfiguration and accommodation to various environmental conditions. The paper at hand describes a wheeled, actively articulated transportation system in form of a mobile robot and experimental small-scale model, respectively. The system is equipped with a shared control system to safeguard its efficient mobility with respect to performance indices maneuverability, terrainability and trafficability, both, on structured and rough terrain. The developed shared control system is introduced and first experimental results are presented.

Provision of Basis for a New Snake-Like Reconnaissance Robot for Disaster Situations

It frequently comes to building collapses all over the world. Often people are buried alive. They must be rescued and saved by rescue teams. It depends on the time that passes during a rescue whether a person can still be rescued alive. Especially the information which is available about the exact position of a person buried alive is decisive for a fast accomplishment of rescue actions. Accordingly the exact localization of victims buried alive is of primary importance. It is the only way, a fast rescue and salvation can be started. However, biological and technical locating equipment available today shows numerous weak points. This refers particularly to the precision of position determination of the victims. But the essential disadvantage of the utilizable technologies is that a collapsed building cannot be entered actively. There is no equipment available that enables a deep penetration into ruins for inspection and exploration tasks, without the necessity of using heavy machines. In a research project currently funded in Germany these difficulties shall be encountered by a part autonomous, energy self-sufficient and remotely controlled reconnaissance robot. It will become a motion system, which orientates its design and behavior at the biological archetype snake. The paper at hand introduces the state-of-the-art of technology and research in the fields of locating, reconnaissance robots as well as snake robots. Originating from a multifunctional locomotion system that has been already implemented successfully, elements for a robot system to be newly developed are introduced and discussed.Copyright

A wireless contact point sensor for tracked robots

Mobile robots offer significant potentials for inspection and surveillance of damage sites after building collapses in the course of a natural or manmade catastrophe. They can be operated semi-autonomously or remote controlled which decreases the danger of the first responders at place. Nevertheless the mentioned scenarios are mostly hard-to-reach and hazardous environments. Therefore mobile robots for the use in such areas have to possess outstanding locomotion and mobility capabilities. Those can be theoretically provided by snake-like robots which have a slender, segmented and modular structure. Furthermore the trafficability and terrainability can be improved by the use of tracks as propulsive elements. Though the use of tracks is best suited for unstructured terrain their design is challenging. This is especially due to the aspect of sensor integration for the detection of physical system-environment-interaction which is necessary for a better terrain adaptation. The paper at hand introduces and describes a new wireless contact sensor for contact point detection for the mobile robot MOEBHIU2S. It focuses on the design, the post integration into the tracks, the signal routing by using RFID technology and first results measured on a test rig.

Prediction of Transformation Behavior of R-Phase SMA Actuators by the Application of Fuzzy Logic

The rhombohedral R-phase is an intermediate phase during the transformation from cubic austenite (B2) to monoclinic martensite (B19’). Compared to the martensitic transformation (B2 → B19’), the R-phase transformation (B2 → R) in NiTi based shape memory alloys (SMA) has a lot of advantages. The main advantages of the R-phase transformation are the very small temperature hysteresis (2-5K) and the high durability (> 100.000 cycles). The main disadvantage of actuators based on R-phase transformation is the small SMA effect (approx. 0,8%). Due to the small temperature hysteresis, the R-phase actuators are usable for temperature sensitive applications in heating technology or in air conditioning. The R-phase transformation doesn’t appear in each SMA alloy and needs a special thermo-mechanical treatment to be induced. Fuzzy logic is an approach to computing, based on degrees of truth, rather than the usual true or false (1 or 0) Boolean logic. It includes 0 and 1 as extreme cases of truth but also the various states of truth. The objective of this paper is to show the applicability of the approach of fuzzy logic in the field of SMA. To gain basic knowledge about influences, different binary NiTi alloys were investigated. The parameters annealing temperature, annealing time and Ni-concentration were varied and their influence on the transformation behavior of the R-phase was noted and added to the fuzzy logic knowledge base.