Dört ayaklı bir robotun momentum farkındalı robust lokomosyon kontrolü

This thesis presented a novel locomotion framework for quadruped robots to maintain dynamically balanced locomotion behavior. The proposed framework consists of two parts: trajectory generation and locomotion controller. Firstly, the trajectory generation provides a vertical center of mass (CoM) trajectory generation based on preview control to accomplish agile locomotion tasks such as jumping and jogging. Conventionally, preview control is implemented for walking planning with constant CoM height since this condition renders the pendulum equation linear. We show that the exact implementation can be done for varying CoM heights while the pendulum frequency is constant. To this end, we compactly derived the infinite horizon and finite horizon time-invariant linear quadratic regulator solutions for potential real-time applicability. Secondly, the proposed locomotion controller provides momentum-aware robust behavior to overcome complicated blind locomotion tasks such as walking on slippery terrain, high-speed trot walking, walking under perturbation, and rough terrain walking. To generate the locomotion controller, we utilize the centroidal momentum concept. To reach this point, we proposed the Centroidal Momentum Observer (CMO)-based controller, which consists of Spatial Force Control with CMO. This controller maintains the robot's operation by working under a nominal wrench and estimating the disturbance wrench. Additionally, We introduced the procedure using the auxiliary variable-based observer design approach to implement CMO. Moreover, the Virtual Model Control (VMC) was implemented to map the wrench obtained from the CMO-based controller as contact force references, which were utilized in computed torque control. The proposed trajectory generation approach and the locomotion controller were tested and compared with conventional approaches via a set of simulation experiments, where we used a realistic model of the quadruped robot Kara. In addition, the preliminary experiment was conducted on the real quadruped robot to test the proposed locomotion controller.