Abstract
Robots are electromechanical systems that need mechatronic approach before manufacturing to reduce the development cost. In this chapter, the modelling of the 8 degrees of freedom (DOF) SCARA robot with a multiple gripper using SolidWorks CAD software and the dynamic study with the aid of MATLAB/SimMechanics is presented. The SCARA with multiple gripper is used for pick and place operation in manufacturing industries. The SolidWorks CAD model of SCARA with multiple grippers is converted into SimMechanics block diagram by exporting the 3D CAD model to the MATLAB/SimMechanics second generation technology environment. The motion sensing capability of the SimMechanics is used for determining the dynamic parameters of the manipulators. The SimMechanics block diagrams and the results of the dynamic study presented in this chapter infer that the structure of the robot can be changed to get the required dynamic parameters.
TopBackground
Nowadays automotive industries are utilizing SCARA robots for handling the body works, engines, chassis, and other components (Jazar, 2009). The flexibility in workspace and the usage of multiple tool is very essential for the above task. This can be achieved by the redundancy in the design of the manipulator. The SCARA with redundant characteristics can be achieved by kinematic modelling of the configuration followed by dynamic study with the help of simulation environment in aid with CAD modelling tools. Rehiara (2011) worked and authored an article explaining the forward kinematics and inverse kinematic approach to find the position of the SCARA robot end effector position using D-H convention and corresponding transformation matrices. Spong, Hutchinson and Vidyasagar (2005) explained the forward and inverse kinematics of various robot configurations, including SCARA comprehensively in his publication. Hernandez, Bravo, de Jesus Rubio and Pacheco (2011) studied forward and inverse kinematics for SCARA, Cylindrical robot with four degrees of freedom to find the end-effector position and orientation which is applicable for TIG or MIG welding. The researchers like Wijesekara Arachchige and Salem Abderrahmane (2013) worked on reconfigurable end effectors. The SCARA robot was reconfigured from 4 DOF to 6 DOF. The state of the joint was selected by the motion of the end effector, and the constraints. This methodology is applied to the SCARA robot manipulator to improve its last joint capability. The researchers replaced the last joint with new reconfigurable joint and robot kinematic theory is applied for model evaluation. Patel and Sobh (2014) made a comprehensive study of manipulator performance measures that are very essential to design and study the applications of robotic manipulators. The kinematic indices, manipulability indices and important performance parameters are referred in his chapter to develop a robot with improvised configuration. These researches facilitates the development of new kinematic model for the SCARA robot with multiple tool which is mentioned in this chapter.
Key Terms in this Chapter
Denavit-Hartenberg Method: In this convention, coordinate frames are attached to the joints between two links. One transformation is associated with the joint and the another one is associated with the link.
Kinematics: Is the science of geometry in motion. It is restricted to a pure geometrical description of motion by means of position, orientation, and their time derivatives.
Kinematic Model: It is a mathematical representation to define the orientation and translation of the manipulator is in the form of homogeneous transformation matrix.
Forward Kinematics: The forward kinematics is when the kinematical data are known for the joint coordinates. The variables of the end-effector in a given Cartesian space are to be computed.
Inverse Kinematics: The inverse kinematics is when the kinematics data are known for the end-effecter in Cartesian space. The joint variables are to be computed.
SCARA: SCARA means selective compliance assembly robot arm. The robotic arm is rigid in the Z-axis and flexible in the XY-axes.
SimMechanics: It is a set of add on block libraries and special simulation features for modeling physical systems in the Simulink environment.