The experimental study on the contact process of passive walking

The passive dynamic walking is a new concept of biped walking. Researchers have been working on this area with both theoretical analysis and experimental analysis ever since McGeer. This paper presents our compass-like pas- sive walking model with a new set of testing system. Two gyroscopes are used for measuring the angles of two legs, and ten FlexiForce sensors are used for measuring the con- tact forces on the feet. We got the experimental data on the passive walking process with the validated testing system. A great emphasis was put on the contact process between the feet and the slope. The contact process of the stance leg was divided into four sections, and differences between the real testing contact process and the classic analytical contact process with no bouncing and slipping were summarized

Modeling and analysis of passive dynamic bipedal walking with segmented feet and compliant joints

Passive dynamic walking has been developed as a possible explanation for the efficiency of the human gait. This paper presents a passive dynamic walking model with segmented feet, which makes the bipedal walking gait more close to natural human-like gait. The proposed model extends the simplest walking model with the addition of fiat feet and torsional spring based compliance on ankle joints and toe joints, to achieve stable walking on a slope driven by gravity. The push-off phase includes foot rotations around the toe joint and around the toe tip, which shows a great resemblance to human normal walking. This paper investigates the effects of the segmented foot structure on bipedal walking in simulations. The model achieves satisfactory walking results on even or uneven slopes.

Passive walker that can walk down steps:simulations and experiments

A planar passive walking model with straight legs and round feet was discussed. This model can walk down steps, both on stairs with even steps and with random steps. Simulations showed that models with small moments of inertia can navigate large height steps. Period-doubling has been observed when the space between steps grows. This period-doubling has been validated by experiments, and the results of experiments were coincident with the simulation.

Planning and Control for Passive Dynamics Based Walking of 3D Biped Robots

Efficient walking is one of the main goals of research on biped robots. Passive Dynamics Based Walking （PDBW） has been proven to be an efficient pattern in numerous previous approaches to 2D biped walking. The goal of this study is to develop feasible method for the application of PDBW to 3D robots. First a hybrid control method is presented, where a previously proposed two-point-foot walking pattern is employed to generate a PDBW gait in the sagittal plane and, in the frontal plane, a systematic balance control algorithm is applied including online planning of the landing point of the swing leg and feedback control of the stance foot. Then a multi-space planning structure is proposed to implement the proposed method on a 13-link 3D robot. Related kinematics and planning details of the robot are presented. Furthermore, a simulation of the 13-link biped robot verifies that stable and highly efficient walking can be achieved by the proposed control method. In addition, a number of features of the biped walking, including the transient powers and torques of the joints are explored.

Preface

Micromechanics aims mainly at establishing the quantitative relation between the macroscopic mechanical behavior and the microstructure of heterogeneous materials.

Motion analysis of passive dynamic walking with a rigorously constraint model: A necessary condition for maintaining period-1 gait

The friction force is an important environmental factor that influences dynamic walking.While most of the related works simply assume static friction or Coulomb friction,we use the LuGre friction,which accounts for both static and dynamic effects,to model the horizontal ground reaction force of passive dynamic walking.We present a detailed mathematical modeling method and perform numerical simulations using it.Furthermore,we analyze the ground surface cases of the Coulomb friction condition and static friction condition to verify the model’s generalization.We discover the required condition for the existence of the period-1 gait through investigation.Our mathematical model and theoretical analysis add to our understanding of passive dynamic walking,which helps to positively utilize the natural dynamics of the legged locomotion system in control design.

A self-stabilised walking gait for humanoid robots based on the essential model with internal states

Walking stability is one of the key issues for humanoid robots.A self-stabilised walking gait for a full dynamic model of humanoid robots is proposed.For simplified models,that is,the linear inverted pendulum model and variable-length inverted pendulum model,self-stabilisation of walking gait can be obtained if virtual constraints are properly defined.This result is extended to the full dynamic model of humanoid robots by using an essential dynamic model,which is developed based on the zero dynamics concept.With the proposed method,a robust stable walking for a humanoid robot is achieved by adjusting the step timing and landing position of the swing foot automatically,following its intrinsic dynamic characteristics.This exempts the robot from the time-consuming high-level control approaches,especially when a full dynamic model is applied.How different walking patterns/features(i.e.,the swing foot motion,the vertical centre of mass motion,the switching manifold configuration,etc.)affect the stability of the walking gait is analysed.Simulations are conducted on robots Romeo and TALOS to support the results.