A literature review on the optimization of legged robots

Over the last two decades the research and development of legged locomotion robots has grown steadily. Legged systems present major advantages when compared with ‘traditional’ vehicles, because they allow locomotion in inaccessible terrain to vehicles with wheels and tracks. However, the robustness of legged robots, and especially their energy consumption, among other aspects, still lag behind mechanisms that use wheels and tracks. Therefore, in the present state of development, there are several aspects that need to be improved and optimized. Keeping these ideas in mind, this paper presents the review of the literature of different methods adopted for the optimization of the structure and locomotion gaits of walking robots. Among the distinct possible strategies often used for these tasks are referred approaches such as the mimicking of biological animals, the use of evolutionary schemes to find the optimal parameters and structures, the adoption of sound mechanical design rules, and the optimization of power-based indexes

Ouezdou, “Dynamic Simulation of a Humanoid Robot with Four DOFs Torso

Abstract-In this paper, we present the 3D dynamic simulation of walking gait of biped Robian I1 virtual manikin (25 kg weight, 1.10 m height). The biped has 16 degrees of freedom (dofs). Initially, a bio-mimetic approach is used t o model a humanoid biped having 25 dofs based on common European male (75 kg, 1.78 m). Using, human being motion recording, footjground contact model and inverse kinematics, a 3D dynamic simulation of this humanoid is carried out. Scale factorization is used in order t o reach Robian I1 weight and height. A 3D dynamic simulation of t h e Robian size humanoid gives t h e effort wrench exerted by t h e torso on t h e lower limbs. An analysis of t h e six components of this wrench shows t h e existence of two coupling relations. A study of four dofs mechanisms based on General State Equation (GSE) formalism leads us t o a n interesting result. Indeed, four dofs a r e necessary and sufficient t o emulate t h e dynamic effects. An R P P P mechanism is presented in order t o replace Robian upper part. Results of 3 D simulation of t h e 16 dofs resulting biped a r e presented. Z M P control algotithm is used t o ensure dynamic stability of t h e biped during walking gait