A comparative study of kinematic analysis between conventional Theo Jansen mechanism and modified Theo Jansen mechanism developed using ABS for the development of spyder robot

The article shows the modifications and analysis performed in the Theo Jansen Mechanism to achieve the best step height and stride length with less jerk in the mechanism. The Modified mechanism consists of a total of seven links of which five links are binary while two links are ternary, while the original Theo Jansen Mechanism uses eleven Binary links. Various iterations are performed by changing the dimensions of various linkages to obtain step height and stride length by performing path analysis. After completion of path analysis on the mechanism, motion analysis is performed where values of acceleration and velocity graphs are generated. The final selection of mechanism is then done based on achieved step height and stride length while having low values of acceleration in the mechanism and smoothness of the velocity graph. Since, the mechanism is to be used for an eight-legged spyder robot, so static structural analysis of the mechanism is performed with material values of Acrylonitrile Butadiene Styrene (ABS) one of the most popular 3D printing materials used in the Fused Deposition Method (FDM) printing. After completion of all the analyses, the mechanism is used to develop the robot. The body of the robot is designed in CAD software and the body dimensions are finalized based on gear calculation, dimension and position of the motor. After completion of body design in the CAD software, static structural analysis of the overall assembly of the robot is performed. The results show that the design is safe for prototyping.