Stable gait synthesis and analysis of a 12 - degree of freedom eiped robot in sagittal and frontal planes

Legged machines have not been offered biologically realistic movement patterns and behaviours due to the limitations in kinematic, dynamics and control technique. When the degrees of freedom (DOF) increases, the robot becomes complex and it affects the postural stability. A loss of postural stability of biped may have potentially serious consequences and this demands thorough analysis for the better prediction and elimination of the possibility of fall. This work presents the modelling and simulation of twelve degrees of freedom (DOF) biped robot, walking along a pre-defined trajectory after considering the stability in sagittal and frontal planes based upon zero moment point (ZMP) criterion. Kinematic modelling and dynamic modelling of the robot are done using Denavit-Hartenberg (DH) parameters and Newton-Euler algorithm respectively. This paper also proposes Levenberg- Marquardt method for finding inverse kinematic solutions and determines the size of the foot based on ZMP for the stable motion of biped. Biped robot locomotion is simulated, kinematic and dynamic parameters are plotted using MATLAB. Cycloidal gait trajectory is experimentally validated for a particular step length of the biped.