Development of H-M interface for generating motion of the 6 dof Fanuc 2iC robot in a virtual reality BOUZGOU Kamel Laboratory of Power Systems, Solar Energy and Automation USTO.MB.Oran-Algeria bouzgou_kamel@hotmail.fr AHMED-FOITIH Zoubir Laboratory of Power Systems, Solar Energy and Automation USTO.MB.Oran-Algeria zfoitih@yahoo.fr Abstract In this paper, we propose a human-machine interface for simulation, control and generation of motions of the 6 dof manipulator arm the Fanuc 2iC, either in the joint space and also in the operational space while avoiding passage through the singular positions, we have also implemented an algorithm for the generation of motion between two points in the operating space, this interactive interface allows us to visualize the different interpolations in a virtual reality environment based on VRML Matlab, with integration CAD model while solving problems in geometric modeling of the manipulator arm. level three and level five applied to control the arm position, velocity and acceleration. II- DESCRIPTION OF THE GEOMETRY OF FANUC 2iC ROBOT : The kinematics of the wrist is a RRR type, has three revolute joints with intersecting axes, equivalent to a ball (Fig.1). Keywords Motion generation, polynomial interpolation, geometric modeling, 6DOF manipulator arm, virtual reality, VRML, Matlab, CAO. I.INTRODUCTION In telerobotics, the current issue of robotic systems has resulted in the reduction of physical workload of the operator, coupled with an increase in mental load. To carry out a teleoperation action, it is necessary to provide the operator in a position to command / control, information on the progress of the task in the worksite, i.e., assistance to the operator for the perception, decision and control. This largely explains the development of the current artificial assistance techniques. The purpose of this paper is to present the results of a graphical simulation of a 6 dof manipulator robot control Fanuc in an environment with a synthetic representation of the scene (virtual world) which consists of all relevant objects models of the site where the task will run. Updating and animating of this virtual world rely on recent mathematical techniques arising from the field of human reasoning. Initially, the robot has been programmed and modeled by manufacturer software using opaque and limited software for possible extensions. For our use, we will try to develop a software model [12, 13, 14, 15] to an open system using the Matlab mathematical software in a virtual reality that is other than the VRML system. We will simulate the polynomial interpolation, linear, Fig.1. Dimension of the robot and the workspace. [4] 8 From a methodological point of view, we place firstly axes on the joint axes and according to well defined rules [1], Then we determine the geometric parameters of the robot. The placement of frames is indicated in the figure (Fig.2).
R4 Where: And R6 d4 1.Forward geometric model: d3 Forward geometric model is the set of relations which express the position of the end-effector, i.e. operational coordinates of the robot, according to its joint coordinates. Notons : (2) d2 Fig.2. Real architecture of FANUC robot (3) Axes 4, 5 and 6 are concurrent axes, they have the orientation of the end-effector and they do not affect its position, the DH parameters are shown in Table 1. : Transformation matrix of tool frame in the end-effector frame. We present only elements of the positions as follow: Table 1: Modified geometric parameters D-H of the FANUC robot [8] Joint j 1 2 9 d2 3 d3 4 9 d4 R4 5-9 6 9 III- Geometric model of the FANUC robot : (4) 2-Iinverse kinematic model : The inverse problem is to calculate the joint coordinates corresponding to a given end-effector situation, several analytical methods [9, 1] to find the inverse geometric model and iterative as [6,7] The homogeneous transformation matrices: (5) With orientation matrix for frame 2-1-1 computation of, and : (6) (1)
With: (7) For the first equality of (6) we make: ; So by identification: And the all becomes: (8) (13) For the first equality of (8) we extract (9) And for the second equality of (8) we extract: (14) (1) we pose: (11) Thus: We replace in (11): Equation (in terms of ) of second degree admits two reals solutions if where: Therefore: We replace its in (9) et (1) we obtain: (12) 2-1-2-computation of, and We found, and ; so, matrix being known: IV. Graphical interface (15) Several Toolboxes have been developed and integrated in the MATLAB library, which are a valuable aid for scientific research, and that in many areas of engineering [16]. We tried, in our case; design a graphical interface for simulation, command and viewing different graphs positions, velocity and acceleration according to the laws of interpolations to be presented in the remainder of this paper. To customize our own library, we designed our functions from predefined functions in Matlab to simplify and facilitate the programming, e.g., the M_orientation function; we return the orientation matrix, as shown in figure (fig.3)
- The motion between two points with free trajectory. -the motion between two points through intermediate points. -The motion between two points with a constraint trajectory. -The motion between two points with a constraint trajectory through intermediate points. The motion generation is in articular spase also in operational space..[1] 1) Motion generation in the articular space The motion between two points and according the time t is described by a following equation [1]: And velocity: Fig3. The MATLAB code of M_Orientation function Several functions have been created and programmed for the forward and inverse kinematics, for example: function [px,py,pz] = mgd(teta1,teta2,teta3,teta4,teta5,teta6 ) Le modele geometrique inverse : function [teta1,teta2,teta3,teta4,teta5,teta6,angl ess] = mgi(px,py,pz,a) Etc The result of our work has led to design an interface for simulation and control of the FANUC manipulator arm FANUC (Fig. 4) with CAD [3,4,5]. With: This approach is shown schematically in Figure (fig.5) (t) Génération de mouvement en q Asservissemen t Fig 5.Motion generation in the articular space A several function allow to satisfy a passage through at t= and by at. We study successively: linear interpolation: (16) polynomial interpolation of three degree: Where: (17) polynomial interpolation of five degree: Where: (18) Bang-Bang law. Fig.4. Main interface IV- Motion generation The motion generation is to calculate the steps and reference guidelines in position, velocity and acceleration, which assure the passage of robot by a desired trajectory.. We distinguish the following motions: We were able to incorporate all these laws in our GUI as shown in (Fig. 6), with a choice of initial and final points.
In our research, we implemented an algorithm that generates us a line trajectory between two points in operational space, the result is shown into the following interface (fig.9) Fig. Motion generation interface GUI We have developed a GUI to choose the type of interpolation and also the input (position, velocity and acceleration), as shown in the figure (Fig. 7) Fig.9. motion generation of the rectilinear trajectory in operational space V-Conclusion : Fig.7. Interface for choice the interpolation type for visualized The application includes functions created using predefined basic functions of MATLAB, for the calculation and simulation of geometry, velocity and motion generation, we were able to program all the laws of polynomial interpolations and plotted it in one interface, which help us to simulate and interpret the different variables of position, velocity and acceleration. we consider for our future work on the robot controller via TCP / IP. The mathematical and data processing concepts of our research can be adapted to any 6 dof manipulator arms with intersecting axes such as KUKA, ABB etc.... 2) Motion generation in the operational space Reference: The motion generation in operational space allows control of the geometry of trajectory. (Fig.8) - It involves the transformation in joint coordinates of each point of the trajectory (use of IK program). - It can be defeated when the calculated trajectory passes through a singular position. Génération de mouvement en X (t) (t) MGI Asservissement MGD Fig.8.. diagram of motion generation in operational space W. khalil,e.dombre Modelisation identification et commande des robots 2 edition 1999. [2] J.-P.LALLEMAND. (1994). Robotique Aspects fondamentaux. Paris. [3] K.Bouzgou,M.A.Bellabaci,Z.Ahmed-Foitih Modélisation, commande et génération de mouvement du bras manipulateur FANUC 2Ic manipulateur FANUC 2iC, memoire Master informatique industrielle 212-213. [4] Récupéré sur FANUC Robotics: http://www.fanucrobotics.com [5] GRABCAD. Récupéré sur http://grabcad.com/ [6] B. Benhabib, A.A.Goldenberg, and R.G.Fenton, A solution to the inverse kinematics of redundant manipulators IEEE,1985 [7] I.Toyosaku, K.Nagasaka, and S.Yainamoto A New Approach to Kinematic Control of Simple Manipulators IEEE 1992. [8] J. Denavit and R. S. Hartenberg, A Kinematic Notation for Lowerpair Mechanisms Based on Matrices, Journal of Applied Mechanics, 1955. [9] D.L.Pieper the kinematics of manipulators under computer control,phd thesis,stanford university 1968. [1] R.C.P.Paul, Robot manipulators:mathematics,programming and control MIT press,combridge 1981. [11] M.Vaezi,H.E.S. Jazeh Singularity Analysis of 6DOF Stäubli TX4 Robot International Conference on Mechatronics and Automation August 7-1, Beijing, China, IEEE 211. [1]
[12] A.M. Djuric,M.Filipovic,L. Kevac Graphical Representation of the Significant 6R KUKA Robots Spaces SISY 213 IEEE 11th International Symposium on Intelligent Systems and Informatics September 26-28, 213, Subotica, Serbia [13] F. Chinello,S. Scheggi,F. Morbidi, D.Prattichizzo KCT: A MATLAB toolbox for motion control of KUKA robot manipulators, IEEE 21 [14] W. Guan Hao,Y. Yee Leck,L. Chot Hun 6-dof pc-based robotic arm (pc-roboarm) with efficient trajectory planning and speed control IEEE 211 [15] P.I. Corke. A Robotics Toolbox for MATLAB. IEEE Rob. Autom. Mag., 3(1):24 32, 1996. [16] E.K ONG,F.L.TAN Menu-driven graphical interface for MATLAB Control Design int.j.engng Ed.vol.16