Industrial robots have become one of the effective support tools for human labor. Robots are a solution to replace humans in repetitive tasks and in environments where humans cannot work. Robots have become one of the factors responding to the Industrial Revolution 4.0. Automatic control devices require high-precision control quality. Therefore, in this paper, we focus on researching controlling the position of the actuator accurately based on the PID algorithm. First, we study the forward and inverse kinematics of a three-joint robot. Second, we design the robot model on inventor software and transfer the 3d model in inventor software to Matlab Simmechanics. Third, modeling robot model on Simulink to simulate and evaluate the results achieved

This article presents how to speculate, design and simulate a mechanical horse based on the point of view of the military man Khong Minh, a talented character in the work "Three Kingdoms" (author La Quan Trung). The behavior of this type of horse closely resembles that of a real horse. That is, it can walk, run, carry goods or people. It is made mainly of wood or steel. The authors speculated that Khong Minh placed a leaf spring in the belly of the mechanical horse. Soldiers just need to rotate so that the leaf spring twists, it will store energy in the form of potential energy. Then, it slowly unfolds, and the potential energy is converted into kinetic energy, transmitting motion to the mechanisms connected to the horse's legs. Finally, the mechanical horse lifted his leg and was able to walk. Despite such speculation, when recreating a mechanical horse, our team of authors used a battery-powered motor instead of leaf springs and gear transmissions as a pre-assembled transmission part in the belly of the mechanical horse. We design additional parts such as the head, tail, belly, legs, etc. to create a complete mechanical horse. The design goal of the author's mechanical horse is to clear people's doubts about the "wooden buffalo mechanical horse" in the literary work "Three Kingdoms". At the same time, this type of mechanical horse is also applied as an amusement ride for people in tourist areas and as a children's toy in the family.

With the development of information technology, many applications of robots are increasingly being applied to support research, learning, and teaching. This paper mainly investigates the modeling and simulation of a robotic arm with 3 degrees of freedom (dofs) for different applications. First, Kinematics and dynamics model of the robot based on the standard Denavit Hartenberg (D-H) modeling method, where the forward kinematics of robot is analyzed and computed to obtain by using the inverse kinematics, and then the solution of the robot dynamics is derived. Second, a CAD model of the robot is designed on CATIA software to convert to MapleSim software to simulation and control. Final, numerical simulation is presented to display results. This work provides a potential basis for the realization of the robotic arm in the industrial, education, and research field, which is of great significance for improving manufacturing efficiency and support teaching and research in the robot field.