A Robust Biped Locomotion Based on LinearQuadraticGaussian Controller and Divergent Component of Motion Generating robust locomotion for a humanoid robot in the presence of disturbances is difficult because of its high number of degrees of freedom and its unstable nature. In this paper, we used the concept of Divergent Component of Motion (DCM) and propose an optimal closedloop controller based on LinearQuadraticGaussian to generate a robust and stable walking for humanoid robots. The biped robot dynamics has been approximated using the Linear Inverted Pendulum Model (LIPM). Moreover, we propose a controller to adjust the landing location of the swing leg to increase the withstanding level of the robot against a severe external push. The performance and also the robustness of the proposed controller is analyzed and verified by performing a set of simulations using MATLAB. The simulation results showed that the proposed controller is capable of providing a robust walking even in the presence of disturbances and in challenging situations.

Motion Decoupling and Composition via Reduced Order Model optimization for Dynamic Humanoid Walking with CLFQP based Active Force Control In this paper, 3D humanoid walking is decoupled into periodic and transitional motion, each of which is decoupled into planar walking in the sagittal and lateral plane. Reduced order models (ROMs), i.e. actuated Springloaded Inverted Pendulum (aSLIP) models and HybridLinear Inverted Pendulum (HLIP) models, are utilized for motion generation on the desired center of mass (COM) dynamics for each type of planar motion. The periodic motion is planned via point foot (underactuated) ROMs for dynamic motion with minimum ankle actuation, while the transitional motion is planned via footactuated ROMs for fast and smooth transition. Composition of the planar COM dynamics yields the desired COM dynamics in 3D, which is embedded on the humanoid via control Lyapunov function based Quadratic programs (CLFQPs). Additionally, the ground reaction force profiles of the aSLIP walking are used as desired references for ground contact forces in the CLFQPs for smooth domain transitions. The proposed framework is realized on a lowerlimb exoskeleton in simulation wherein different walking motions are achieved.