Design and Kinematic Analysis of Quadrupedal Cat-Like Robot

Robotics technology is one of the most important technologies in determining the progress of civilization in the world. Since the invention of mobile robot technology, the development of robotics has occurred in almost every sector of life, such as the military, manufacturing, industry, health, and others. On a mobile robot, there are two classifications of mechanisms used, namely the legged mechanism and the wheel mechanism. Of the two mechanisms, legged robots have advantages over wheel robots, because leg robots can pass through all the terrains to be traversed. In the legged robots, quadruped robots are easier to manufacture and control than a two-legged (biped) robot, and a six-legged robot (hexapod). Therefore, this study seeks to develop a Quadrupedal Robot inspired by the structure and movement of a cat. In this first phase of research, the robot was manufactured with a total weight of 1293 g and dimensions of 43 cm long, 20.5 cm wide, and 22 cm high. The equation of motion uses the geometry equation to model and determine the position of the end-effector (leg-tip) and perform a kinematic simulation with the toolbox in Matlab. The result of 2D forward kinematics is highly nonlinear that it is difficult to solve by analytical solutions. Symbolic toolbox and ‘solve’ command under Matlab software is utilized to obtain the joint angle inputs. The acquired angles are then used as input on the Simulink block to be embedded on the microcontroller, and the actuator on the robot, before the prototype is carried out in a straight walking test. From the results of walk test, the robot can successfully walk without falling. The robot can walk without orientation feedback control.