Doru Bardac

Controlling of the 3D Space Trajectory of the Multi Robots Applications by Using the Proper Iterative Pseudo Inverse Jacobian Neural Network Matrix Method

In many applications we used the multi robots with the central coordination of the 3D space trajectory. In the controlling of the space movement of the end effecter of the all robots from this type of applications and the robot’s joints one of the most important problem is to solve the forward and inverse kinematics, that is different from the single robot application. It is important to know with the extreme precision the joints relative displacements of all robots. One of the most precise method to solve the inverse kinematics problem in the robots with redundant chain is the complex coupled method of the neural network with Iterative Jacobian Pseudo Inverse method. In this paper was proposed and used the proper coupled method Iterative Pseudo Inverse Jacobian Matrix Method (IPIJMM) with Sigmoid Bipolar Hyperbolic Tangent Neural Network with Time Delay and Recurrent Links (SBHTNN-TDRL). The paper contents the mathematical matrix model of the forward kinematics of multiple robots applications, mathematical model of the proper iterative algorithm and all proper virtual LabVIEW instrumentation, to obtain the space conventional and unconventional curves in different Euller planes for one case study of three simultaneously robots movement with extreme precision of the end-effecter less than 0.001mm. The paper shown how can be changed the multi robots application in to one application with parallel robot structure with three independent robots. The presented method and the virtual instrumentations (VI) are generally and they can be used in all other robots application and for all other conventional and unconventional space curves.

Proper LabVIEW Instrumentation of the Robot’s Kinematics and Dynamics Behavior

The most important in the study of the robots is the kinematic and dynamic analyze. Many researchers studied the kinematics or dynamics without simulation and assisted analyze that it is very heavy to understand the behavior and to show some characteristics. The paper shows one assisted method by using the virtual proper LabVIEW instrumentation (VI). For the forward kinematics (FK) and for direct dynamics (DD) was used one recurrent matrix method which was developed with quaternion algebra, that will be possible to use in many different other types of robots, only by initial settings of the type of joints, the movement axis, the home position, the dimension of each robot’s body, the application point in the working space of the manufacturing cells and the internal coordinates in each joint. For the inverse kinematics (IK) we used the Iterative Pseudo Inverse Jacobian Matrix Method (IPIJMM) coupled with the proper Sigmoid Bipolar Hyperbolic Tangent Neural Network with Time Delay and Recurrent Links (SBHTNN-TDRL). The paper describe all steps in one case study to obtain the space curve in different Euller planes by using one arm type robot and the proposed VI-s. The presented method and the LabVIEW VI-s are generally and they can be used in all other robots types and for all other conventional and unconventional space curves.

Prediction of the Structural Dynamic Behavior of High Speed Turning Machine Spindles

This paper presents a method to investigate the dynamic behavior of a turning high-speed spindle system. The machine tool main spindle unit is focused on direct driven spindle units for high-speed and high performance cutting. This paper analyzes the static behavior for a turning machine spindle and presents some activities to improve the CAD model for such complex systems. The proposed models take into account the spindle with the bearing detailed system. The analysis was performed during the design activity and was based on Finite Elements Method. Starting from the 3D model, using FEM done by means of ANSYS analysis, structural dynamic behavior was evaluated. The aim of this paper is to develop a finite element model of the machine spindle system and use this method for design optimization. The 3D model was designed using the Solidworks CAD software. In order to obtain accurate dynamic characteristics of the spindle-bearing system during the design stage, the finite element model is simulated using dedicated software, and a method in which springs and damping units imitate bearing support. The proposed method can predict the regular pattern in which bearing stiffness and bearing span affect natural frequency and harmonic response. The research demonstrates that this method predicts the dynamic characteristics of the spindle-bearing system therefore it can be a reference for dynamic optimization design of spindle-bearing systems in turn-milling centers. The static analysis was presented in another paper. The thermal analysis will be presented in a future paper.

Finite Element Analysis for Static Behaviour of the CNC Turning Machine Spindle

This paper presents a method to investigate the characteristics of a turning high-speed spindle system. The geometric quality of high-precision parts is highly dependent on the performance of the entire machining system,especially by the main spindle behaviour. The machine tool main spindle units is focused on direct driven spindle units for high-speed and high performance cutting. This paper analyzes the static behavior for a turning machine spindle and presents some activities to improve the CAD model for such complex systems. The proposed models take into account the spindle with the detailed bearing system. The analysis was performed during the design activity and was based on Finite Elements Method. Starting from the 3D designed model, using FEM done by means of ANSYS analysis the structure stiffness was evaluated and, by consequence, the influence on the machine tool precision. The aim of this paper is to develop a finite element model of the machine spindle system and to use this method for design optimization. The 3D model was designed using the SolidWorks CAD software. The static analysis was completed by modal, harmonic response and thermal analysis, but their results will be presented in other papers.

Contributions to Soil Resistance Mapping for Increasing Parts Durability for Agricultural Machinery

The Paper Presents a Study Conducted by the Authors for Mapping of Soil Resistance According to Depth and Space. the Determination of Penetration Resistance Pressure of the Soil was Done in Field, with a Penetrograph, and the Experimental Data were Statistically Analyzed, in Order to Assess the Loading Regimes Faced by the Active Organs of Agricultural Machinery while Working for Soil Processing, for Estimating the Influences on their Durability. A Durability Case Study on a Real Reversible Chisel Type Cultivator Blade was also Conducted, Using a 3D Finite Element Solid Model and Two Classical 2D Models in Order to Determine its Fatigue Response, Using as Loads the Determined Soil Resistance Pressure.

Comparative Study on Determining the Drilling Force Regression at Drilling Composites Materials

Composite materials are used extensively because of their higher strength to weight ratios and, when compared to metals, offer new opportunities for design. However, being non-homogenous, anisotropic and reinforced with very abrasive fibers, these materials are difficult to machine. In this current article is present a comparative study of results obtained in determining the drilling force regression at drilling a tree types composites material with polymeric matrix and fiber glass.