Applied Mechanics and Materials Vol. 762

Abstract: This paper is devoted to the presentation of new formulations on the higher order motion energies that are used in the advanced dynamic study of robots. Integral part of these mechanical systems are the mechanical robot structures, on which an application will be presented in order to highlight the importance of the higher order motion energies regarding the dynamic behavior. In current dynamic studies, the kinetic energy is used as a central function in Lagrange - Euler equations. This paper extends the study by developing the acceleration energies of first, second and third order and their implementation in differential equations of motion of third and fourth order, which gives the possibility of applying the initial motion conditions in positions, velocities and accelerations of first and second order. This leads to a more precise control on the transitory motion phases of the multibody systems, in which the robot structures are included.

Abstract: This paper shows the steps of structural synthesis and analysis, kinematic synthesis and analysis and CAD constructive design of a reconfigurable modular anthropomorphic gripper with three fingers. Modularity refers to the fact that the gripper variants can be obtained with only two modules, namely a platform and a finger. Reconfigurability refers to the fact that the main variants of the gripper can be obtained by changing the relative position of the fingers. It is demonstrated that the three-finger gripper has four main configurations that provide important functionality even reported to the functionality of a three-finger gripper with continuous reconfigurability. To verify correct operation, functional CAD simulation is performed, and for dynamic operation simulation, we turn to the advanced software ADAMS. An important advantage of this type of gripper, compared to those with continuous reconfigurability, is much lower price at a relatively good functionality for current robotic gripping operations. The paper makes possible subsequent turn to prototype, testing the gripper operation, as it is mounted on an industrial robot, and optimization of its operation by equipping it with contact sensors. The simulation of the gripper operation in virtual environment and data transmission to the real gripper is a solution of interest that will be studied in future research.

Abstract: The paper presents the general structure and the feedback control method of a compact type of driving simulator, having a mobile suspended seat actuated by pneumatic muscles. The completed simulator is intended to be used as an advertising demonstrator for the university and also for various research projects. In order to better observe the viability and behavior of the proposed feedback structure, a scaled model is constructed using similar pneumatic muscle actuation of a 3+1 DOF suspended mass. For analysis purposes, multi-step pressure and tri-state muscle contraction control is employed. The feedback data is exchanged between the software simulator and the motion control PLC by using a custom software application.

Abstract: This paper presents the workflow to create a robotic humanoid hand simulation environment using two top software packages and also the implementation of an intelligent hybrid force - position control method using neural networks for force closing operation of a humanoid robotic hand modeled in the 3D virtual environment. The benefits that the 3D modeling provides are described and then the results of the proposed method are presented. This approach allows studying the motion of the robotic system under different circumstances without any greater costs.

Abstract: This paper presents a comparative kinematic and dynamic analysis of a Delta parallel robot based on numerical simulations of the rigid vs. flexible links robot models. The flexible links numerical models are derived using AutoFlex module of Adams software. Finally, the conclusions regarding the obtained results useful in manipulator constructive design are presented.

Abstract: In this paper, the geometrical model of a guiding device mechanism of a parallel topology robot proposed as a flight simulator is presented. For the operation simulation, the input parameters are the relative displacements of driving kinematical joints links versus time. The displacements of 2 characteristic points on the mobile platform are determined, as well as their velocity and acceleration variations. Also, the variations of kinematic and potential energy of human operator geometrical model and the variation of power consumption for different operating conditions are accomplished. For geometrical modeling and dynamic simulation, SolidWorks software is used.

Abstract: This paper proposes a study on the workspace of the guiding device mechanism of a parallel topology robot. The kinematical scheme and the geometrical model of the guiding device mechanism of the parallel topology robot are presented. The lengths of binary links between the platforms determine the shape and the volume of the parallel robot’s workspace; different boundaries of the workspace are presented. Thus, variation of the workspace in both volume and shape is studied, depending on the binary link lengths, using for modeling and simulation SolidWorks software.

Abstract: Driving simulators represent a novel way to reproduce the movements of a vehicle with the purpose of testing different cars, to prevent dangerous situations, entertainment and also to train the professional drivers. More, they are used to render the effects of the interactions between the car and the road, as a consequence of the constrains imposed by the road: different folds, cavities. This work presents the topological synthesis, the kinematic analysis and the virtual modeling of driving simulator. The mechanical structure of the simulator is modeled in the Matlab/Simulink environment, generally used the advantages of numerical solutions.

Abstract: The major disadvantage of the parallel robot is that the singular positions are comprised into the work space. The singular positions are the particular poses for parallel robot DELTA where the mobility of the structure is not longer zero when the actuators are locked. Present analysis is focused on the determinant value of the Jacobian matrix of the kinematic analysis equation system, written using Denavit – Hartenberg transformation matrices. The kinematic equations possess the algebraic and trigonometric character, so that the inverse singularity analysis can be formulated. By instantaneous mobility analysis of the moving platform of the parallel robots, the geometric conditions for the forward singularity configurations are identified. Finally, a numerical example is solved in order to illustrate the variation of the Jacobian determinant in the proximity of a singular position.

Abstract: The paper presents a new medical parallel robot for brachytherapy. Brachytherapy (BT) is a relatively new and efficient medical technique for cancer treatment that enables to deliver higher doses of radiation to more-specific areas of the body, compared to the conventional form of radiation therapy that projects radiation from a machine outside the body. BT implies the implant of radioactive seeds inside the tumor, through specific needles, thus affecting only the tumor while avoiding unnecessary irradiation of the healthy tissue. Compared to the most of the brachytherapy designed only for treating the prostate, the medical robot presented in the paper is designed for hard-to-reach areas (such as the retroperitoneal area or the mediastinum). An approach regarding the robot structural synthesis, kinematics is presented followed by some simulation results obtained for a specific BT needle trajectory.