Applied Mechanics and Materials Vol. 762

Abstract: A geometric and kinematic study between two structures of robots was performed, respectively a mechanical anthropomorphic structure, with bars and gears, with four degree of freedom, (dof), redundant (4R), which can avoid obstacles and a parallel manipulator with translation on three axes (3T). This 3T structural solution allows rapid and precise movements, which are important characteristics for machine building industry. All these features make the parallel manipulator to be an attractive alternative to the serial ones for high precision operations in a limited workspace.

Abstract: The last years a large number of vehicles have been developed for their mobility characteristics over rough terrains. The new modular walking robot MERO* (MEchanism Robot- *Pelecudi Ch et.al.) by reconfiguring their architecture are built to displace the heavy loads on the rough terrains. The main characteristic of the modular walking robot is that they are able to move away on not arranged, horizontal and rough terrains. The modular mechatronic system protect much better the environment when its contact with the soil is discrete, a fact that limits appreciately he area that is crushed. Operation of autonomous walking robot MERO movement implies the existence of a close link between planning movements, environmental perception and executions order to obtain an appropriate behaviour in weakly structured environments. For further acquisition of terrain information, we propose installed active force sensor for terminal leg. This paper describes the detailed design and the prototype characterization of a novel tactile sensor force/moment sensor for MERO an intelligent walking robot’s .

Abstract: Brachytherapy (BT) is a modality to treat cancer by inserting needles into a patient to deliver radioactive sources direct to the diseased tissue. The efficiency of the treatment is determined by the positions of the needles. A robot can be used in order to increase the precision of the needles locations. This paper presents an approach for needle trajectory planning based on isomorphic mapping from a haptic device. A virtual reality environment has been modelled containing a 3D reconstructed abdominal model of the patient. Needle insertion using the BT robot is controlled using a Force Dimension Omega haptic device. The developed software application allows the users to practice robotic needle insertion and to determine the most appropriate locations for the BT needles.

Abstract: Inspection and exploration represent a challenging domain in the field of robotics because of the hazardous and limited workspace to which the robots have to adapt and because of the reduced ability to monitor and acquire data about the inspected environment. A pipeline inspection robot must ensure sufficient traction force to pull its tether cable and other equipment while travelling inside a pipeline to complete inspection, maintenance, and repair tasks. This paper presents the design of three minirobots with adaptable structure for in pipe inspection and the experimental determination of their traction force. To measure the traction force of the minirobots, the Xplorer GLX digital measuring device was used.

Abstract: The paper presents the development of a smart sensor system that is used for measuring pipe network parameters. The developed sensor is intended for use with in pipe inspection robots that can independently explore and evaluate the constructive parameters and the condition of the pipe network. The proposed system is developed around the Atmel ATMega16 microcontroller which is connected to a set of sensors and to the robot. The sensor system was tested using the ROBIN250 mobile robot and the obtained results are presented in the paper.

Abstract: The differential impact equations of motion are developed using an nonlinear contact force. The nonlinear equations of motion are written using symbolical MATLAB and are solved using numerical techniques. The impact equations are based on the Kogut-Etsion model. The numerical results are obtained for different geometries of the link, different coefficients of friction, and different initial conditions. The coefficient of restitution (COR) is discussed for specific cases. The results can be used for the impact of mobile robots with different type of surfaces.

Abstract: This paper deals with the analysis of the mechanical system of a self-propelled vehicle on the tires able to move on an uneven ground whilst his platform stays horizontally. It is question to simulate the movement of a desmodromic robot which moves in an environment represented by a 3D surface. The robot has a mechano-hydraulic system which is able to modify the geometry of chassis in the aim of maintaining the platform always at horizontal while in movement, no matter the soil configuration (of course between some limits).The horizontalisation mechanism with the rolling train hydraulically driven presents some difficulties because of the non holonomic constraints of the wheels ([1, 2]). In order to make the application of the multipoles theory in the structomatical model must be introduce some simplifications in the contact joint. Thus, the non holonomic joints are presented like gamma active joints (with the condition of controlled rolling/skidding).This is an extension of the general principle of mechanism formation ([3]) according who any mechanical structure can be broken in genes upon an unique formula (the genetic code of the mechanism).Because of the complexity of the calculus the study of mechanism was divided in a few chapters: geometrics, structomatics, kinematics, kinetostatics and dynamics etc. The uttermost important and difficult part is the kinematical model because of the non-linearity of the equations. This article presents the first two items; the others will be the matter of future papers.

Abstract: This paper addresses the concept of “natural interaction”, defined as a way to interact in a simple, human-like and intuitive manner with personal assistive robots. A human-robot interaction system was developed for this purpose in order to provide means for expert and non-expert users to cooperate and interact with an assistant humanoid robot (Nao) operating in a domestic environment, allowing them to express their instructions as combinations of gestures and speech inputs.

Abstract: In this paper the authors present a software platform made using Matlab for studying hexapod robot stability in gravitational field and some basic locomotion simulations over obstacles. For the proposed design of the leg was calculated the kinematical model and a workspace analysis was made. The trajectory generator for the leg tip was implemented using piecewise cubic spline interpolation method. Next are presented the most common types of obstacles and the influence upon robot locomotion. The analysis of the robot static stability is made for different cases of loco-motion. The paper includes some simulation results related to the static gravitational stability de-pending on the support polygon, single leg control and locomotion over common types of obstacles.

Abstract: This paper presents the development of a voice and gesture based interface (HMI – Human - Machine Interface) for the human control of a mobile robot. The application utilizes the Microsoft Kinect sensor and its Visual Studio C# libraries for voice and gestures recognition. Once, the specific voice commands or gestures are recognized, the controller (a PC or Laptop) sends specific commands to a microcontroller (ATmega2560 on an Arduino Mega board). The microcontroller is mounted on the mobile robot and controls the robot’s motors. Also there are presented some limitations of the Kinect sensor to be taken into consideration when using it.