Design optimisation of industrial robots using the Modelica multi-physics modeling language
Superior performance of industrial robots can only be achieved if the interaction of mechanics, electronics and software is taken into account already in the design phase. Conventional approaches to modelling, however, cannot cope with such multi-physics systems. The new Modelica modelling language has been specifically developed for this purpose. It also significantly increases re-usability of model components, since components adapt to the connection structure in which they are used. In the European resarch project “Real-time Simulation for Design of Multi-physics Systems“ (RealSim), efficient tools for modelling, simulating and optimising industrial robots are developed. A general Modelica MultiBody library (freely available from [1] or [2]) formed the basis for the development of a specific robot component library. A development environment for creating robot models out of the available components was provided, in which initial calculations to verify the first rough design can also be performed. Tools for automated optimisation were developed that take the initial design as the starting point. Afterwards, the performance of a design can than be verified in a real-time simulation before investing in building a real prototype. These powerful development tools provide the basis for an even more efficient development process and superior robot performance in the future.
Kinematic Modelling and Simulation of a 2R Robot Using SolidWorks and Verification by MATLAB / Simulink Regular Paper
The  simulation  of  robot  systems  is  becoming very popular, especially with  the  lowering of  the cost of computers,  and  it  can  be  used  for  layout  evaluation, feasibility studies, presentations with animation and off‐ line programming. The  trajectory  planning  of  redundant manipulators  is  a very  active  area  since  many  tasks  require  special characteristics  to  be  satisfied.  The  importance  of redundant manipulators has  increased over  the  last  two decades  because  of  the  possibility  of  avoiding singularities  as  well  as  obstacles  within  the  course  of motion.  The  angle  that  the  last  link  of  a  2  DOF manipulator makes with the x‐axis is required in order to find the solution for the inverse kinematics problem. This angle  could  be  optimized  with  respect  to  a  given specified  key  factor  (time,  velocity,  torques)  while  the end‐effector  performs  a  chosen  trajectory  (i.e., avoiding an obstacle) in the task space. Modeling  and  simulation  of  robots  could  be  achieved using  either  of  the  following  models:  the  geometrical model (positions, postures), the kinematic model and the dynamic model. To  do  so,  the  modelization  of  a  2‐R  robot  type  is implemented. Our main  tasks  are  comparing  two  robot postures with the same trajectory (path) and for the same length  of  time,  and  establishing  a  computing  code  to obtain the kinematic and dynamic parameters. SolidWorks  and MATLAB/Simulink  softwares  are  used to check the theory and the robot motion simulation. This  could  be  easily  generalized  to  a  3‐R  robot  and possibly therefore to any serial robot (Scara, Puma, etc.). The verification of the obtained results by both softwares allows  us  to  qualitatively  evaluate  and  underline  the validityof  the  chosen  model  and  obtain  the  right conclusions. The results of  the simulations are discussed and an agreement between the two softwares is certainly obtained.
Evaluation of buckling load and dynamic performance of steel shear wall retrofitted with strips made of shape memory alloy
One of the most imperfections of the steel shear wall is out of plane displacements that cause severe damage in both structural and non-structural elements. In this paper, the effects of shape-memory alloys on steel shear walls are investigated. First, a numerical analysis using the finite element method in ABAQUS software has been carried out according to an experimental test. The results of the numerical analysis have been verified with experimental results. Next, shape-memory alloy fibers have been added vertically and horizontally to various parts of the steel shear wall. The results show that retrofitting with the shape-memory alloy reduces the out-of-plane displacement of the steel shear wall under both cyclic and seismic loadings. Besides, the buckling load in the steel shear wall increases when it is retrofitted with the shape-memory alloy. Also, the total out-of-plane movement (accumulated absolute displacements) of the steel shear wall and non-structural damage are controlled by the characteristic of a shape-memory alloy material called “super-elastic”.