An integrated system design interface for operating 8-DoF robotic arm

This study examines the system integration of a game engine with robotics middleware to drive an 8 degree offreedom (DoF) robotic upper limb to generate human-like motion for telerobotic applications. The developed architectureencompasses a pipeline execution design using Blender Game Engine (BGE) including the acquisition of real humanmovements via the Microsoft Kinect V2, interfaced with a modeled virtual arm, and replication of similar arm movements on the physical robotic arm. In particular, this study emphasizes the integration of a human “pilot” with ways to drive such a robotic arm through simulation and later, into a finished system. Additionally, using motion capture technology, a human upper limb action was recorded and applied onto the robot arm using the proposed architecture flow. Also, we showcase the robotic arm’s actions which include reaching, picking, holding, and dropping an object. This paper presentsa simple and intuitive kinematic modeling and 3D simulation process, which is validated using 8-DoF articulated robot to demonstrate methods for animation, and simulation using the designed interface.

Vibration Mode and Motion Trajectory Simulations of an Articulated Robot by a Dynamic Model Considering Joint Bearing Stiffness

Articulated robots are widely used in industries because they can perform manufacturing tasks with complicated movements. Higher speed and accuracy of motions are always required to improve the quality and productivity of products. The vibration characteristics of the robots are an important factor to achieve higher speed and accuracy motions. Robots are increasingly being used for machining. The vibration characteristics must also be considered when designing proper cutting conditions for the machining. To design control and cutting strategies for higher speed and accuracy motions or higher productivity of the machining process, it is effective to investigate the vibration characteristics of the robot and develop a mathematical model which can represents the vibration characteristics. The aim of this study is to investigate the vibration characteristics of an architectural robot and develop a mathematical model which can represent the dynamic behavior of the robot. To achieve this, vibration mode of an industrial architectural robot is analyzed based on measured frequency characteristics. According to the results of the modal analysis, it was clarified that the axial and angular stiffness of bearings of each joint of the robot has a significant impact on the vibration characteristics. Therefore, in this study, a mathematical model of the robot is developed considering the joint bearing stiffness. The mathematical model that also considers the kinematics of the robot, stiffness of reduction gears, control system for motors, and disturbance, such as friction and gravity, is introduced into the model. The control system is precisely modeled based on actual control algorithm in accordance with the implemented source codes. Although mass and inertia of the links are obtained from the 3D-CAD model, stiffness and damping parameters of the bearings and reduction gears are identified by matching the measured and simulated frequency responses. It has been confirmed that the model can adequately represents the vibration mode of the actual robot. Circular motion tests were performed to verify the model. Motion trajectories of the end effector were measured and simulated. As a result, it has been confirmed that the developed model is effective to analyze the dynamic behaviors.

KINEMATICS ANALYSIS AND IMPLEMENTATION OF THREE DEGREES OF FREEDOM ROBOTIC ARM BY USING MATLAB

The kinematics modeling of the robot arm plays an important role in robot control. This paper presents the kinematic model of a three-degree of freedom articulated robot arm, which is designed for picking and placing an application with hand gripper, where a robot has been manufactured for that purpose. The forward kinematic model has been presented in order to determine the end effector’s poses using the Denavit-Hartenberg (DH) convention. For inverse kinematics, an algebraic solution based on trigonometric formulas mixed with geometric method was adopted for a 3 DOF modular manipulator taking into account the existence of a shoulder offset. MATLAB software was used as a tool to simulate and implement the motional characteristics of the robot arm, by creating a 3D visual software package under designing a Graphical User Interface "GUI" with a support simulation from robotic Toolbox (Rtb 10.3). Finally, an electronic interfacing circuit between the GUI program and the robot arm was developed using Arduino microcontroller to control the robot motion. The presented work can be applicable for learning the reality interface design methodology of the other kinds of robot manipulators and achieve a suitable solution for the motional characteristics

FPGA-Based Implementation of Torque Controller for 6-DOF Articulated Robots

This paper aims to design an impedance position-based proportional-integral-derivative (PID) controller based on forward and inverse kinematics of HIWIN RA605 articulated robot, and Field-Programmable Gate Array (FPGA) implementation for a PID torque controller. In order to control the robot, the FPGA needs to output commands to communicate with the AC servo motor drivers. An FPGA-based controller for a 6-degree-of-freedom (DOF) articulated robot that implements several tasks such as hardware implementation, encoder counters, noise cancellation algorithm, analog generators, PID controller, and communication are included, the processing time of the FPGA is 16 μs. Meanwhile, the whole process of the system only takes 82 μs to complete.

Deburring of Resin Molded Products by Sensorless Shape-Tracing Deburring Technology (On the Principle of Sensorless Shape-Tracing Deburring)

This study aims to automate deburring resin workpieces as generated in injection molding by an articulated robot using sensorless shape-tracing deburring technology. Because resin workpieces largely vary in their individual shape differences, as well as installation errors, it is difficult for an articulated robot, which operates solely based on the given teaching in general use, to precisely deburr the workpieces owing to its precision deficiency. In this study, a deburring technology called “shape-tracing deburring” was developed to prevent a tool from breaking into a workpiece while absorbing any positional errors, based on a mechanism capable of mechanically maintaining the force between the tool and the workpiece constant in relation to the shape of the latter. In this way, an articulated robot can stably deburr the workpiece by following any changes in the workpiece shape. In this report, the principle and system of the shape-tracing deburring technology capable of mechanically tracing the workpiece shape without a sensor are discussed. Furthermore, the effectiveness of the developed shape-tracing deburring technology is demonstrated through an example of deburring a resin molded article with an actual cutter complete with a shape-tracing part.

Design and Implementation of 6 DOF ROTARIC Robot Using Inverse Kinematics Method

This paper will discuss the calculation of inverse kinematic which will be used to control the 6-DOF articulated robot. This robot consists of 6 Dynamixel MX-28 smart servo with OpenCM 9.04 microcontroller. The articulated robot has been simplified to 4-DOF because there are no obstacles in the work area and no special movements are required. The calculation method uses the intersection point equation between the ball and the line, so that it can make it easier to determine the point in calculating the kinematic inverse. The experiment is carried out using the desired position as input for the kinematic inverse to produce the angle of each joint. From the angle of each joint obtained, it will be entered into forward kinematic so that the end-effector position will be obtained. The desired position will be compared with the end-effector position, and then how much difference will be calculated. From the experimental results, it was found that the inverse kinematic method which has been inverted by the forward kinematic produces the same final position. Keywords: 6-DOF manipulator, Articulated robot, inverse kinematics and forward kinematics, Dynamixel MX-28, OpenCM 9

Reconfigurable Articulated Robot Using Android Mobile Device

This paper focuses on the design and development of a reconfigurable three-degree-of-freedom articulated robot for conducting pick-and-place tasks. To implement the system, an Android platform for the manual control of an articulated robot using wireless Bluetooth technology was developed. This application allows the user to manually reconfigure the robot following the requirements of the integrated system via a user-friendly display. The articulated robot comprises four motors, three of which are used for positioning and orientation and finally used to carry out the pick-and-place task. An Arduino Un R3 board is used to control the movement of the links via a pulse width modulation method. We introduce a set of conveniently composed kinematic and dynamic mathematical models for positioning the robot’s arms and, in our results and discussion section, calculate and report the torque required to move each joint.