Stability and Dynamic Walk Control of Humanoid Robot for Robot Soccer Player

Robotic football with humanoid robots is a multidisciplinary field connecting several scientific fields. A challenging task in the design of a humanoid robot for the AndroSot and HuroCup competitions is the realization of movement on the field. This study aims to determine a walking pattern for a humanoid robot with an impact on its dynamic stability and behavior. The design of the proposed technical concept depends on its stability management mechanism, walking speed and such factors as the chosen stability approaches. The humanoid robot and its versatility, along with the adaptability of the terrain, are somewhat limited due to the complexity of the walking principle and the control of the robot’s movement itself. The technical concept uses dynamic stability as the potential force of the inertial bodies and their parts so that the humanoid robot does not overturn. The total height of the robot according to the rules of the competition will be 50 cm. In the performed experiment, only the lower part of the humanoid robot with added weight was considered, which is more demanding due to the non-use of the upper limbs for stabilization. The performed experiment verified the correctness of the design, where the torso of the robot performed eight steps in inclinations of a roll angle +4/−2° and a pitch angle +4/−6°.

Implementation of Deep Deterministic Policy Gradients for Controlling Dynamic Bipedal Walking

A control system for bipedal walking in the sagittal plane was developed in simulation. The biped model was built based on anthropometric data for a 1.8 m tall male of average build. At the core of the controller is a deep deterministic policy gradient (DDPG) neural network that was trained in GAZEBO, a physics simulator, to predict the ideal foot placement to maintain stable walking despite external disturbances. The complexity of the DDPG network was decreased through carefully selected state variables and a distributed control system. Additional controllers for the hip joints during their stance phases and the ankle joint during toe-off phase help to stabilize the biped during walking. The simulated biped can walk at a steady pace of approximately 1 m/s, and during locomotion it can maintain stability with a 30 kg·m/s impulse applied forward on the torso or a 40 kg·m/s impulse applied rearward. It also maintains stable walking with a 10 kg backpack or a 25 kg front pack. The controller was trained on a 1.8 m tall model, but also stabilizes models 1.4–2.3 m tall with no changes.

Mechanism Design of a Humanoid Robotic Torso Based on Bionic Optimization

A new torso structure for a humanoid robot has been proposed. The structural characteristics and functions of human torso have been considered to gain inspirations for design purposes. The proposed torso structure consists of six revolute units divided into two basic categories connected in a serial chain mechanism. The proposed torso structure shows more advantages compared to traditional humanoid robots in terms of high degrees of freedom (DOFs), high stiffness, self-locking capabilities, as well as easy-to-control features. Bionic optimization design based on objective function method has been implemented on structural design for better motion performances. A 3D model has been elaborated and simulated in SolidWorks and ADAMS environments for structural design and kinematic simulation purposes, respectively. Simulation results show that the new bionic torso structure is able to well imitate movements of human torso.

Modeling, stability and walking pattern generators of biped robots: a review

Biped robots have gained much attention for decades. A variety of researches have been conducted to make them able to assist or even substitute for humans in performing special tasks. In addition, studying biped robots is important in order to understand human locomotion and to develop and improve control strategies for prosthetic and orthotic limbs. This paper discusses the main challenges encountered in the design of biped robots, such as modeling, stability and their walking patterns. The subject is difficult to deal with because the biped mechanism intervenes with mechanics, control, electronics and artificial intelligence. In this paper, we collect and introduce a systematic discussion of modeling, walking pattern generators and stability for a biped robot.

EXPERIMENTAL REALIZATION OF DYNAMIC STAIR CLIMBING AND DESCENDING OF BIPED HUMANOID ROBOT, HUBO

In this paper, dynamic stair climbing and descending are experimentally realized for a biped humanoid robot, HUBO. Currently, in addition to biped walking on the ground, other types of biped walking such as running, jogging, and stair walking (climbing and descending) have been also studied since the end of 1990. In spite of many years of research works on stair walking, it is still a challengeable topic that requires high performance of control technique. For dynamic stair walking, we designed stair climbing and descending patterns according to a known stair configuration. Next, we defined stair climbing and descending stages for a switching control strategy. In each stage, we designed and adopted several online controllers to maintain the balance. For the simplicity and easy application, the online controllers only use the force and torque signals of the force/torque sensors of the feet. Finally, the effectiveness and performance of the proposed strategy are verified through stair climbing and descending experiments of HUBO.