Passive Dynamic Walking Robot Research Articles

Legged walking robot design applying the adaptive behavior of passive dynamic walking and interconnections among the different dynamics

In this paper, the authors propose a new design methodology for legged walking robots with dynamic characteristics suitable for walking motions by applying the unique properties of Passive Dynamic Walking as design criteria. The authors have identified the ‘adaptive behaviour’, in which the passive dynamic walking robot automatically adjusts its gait to keep walking in response to variations in physical parameters, such as the slope angle or mass, that constitute its mechanics. Furthermore, the authors discovered that this adaptive behaviour enables the transition of the structure and degrees of freedom of the passive dynamic walking robot to different mechanical systems through the application of ‘interconnections among different dynamics’. This paper introduces new mechanical design approach for legged robots that applies these unique properties, with its validity verified through the computer simulations.

Multi-legged Passive Dynamic Walking Robot

Multi-legged Passive Dynamic Walking Robot

Designing passive dynamic walking robots for additive manufacture

Purpose Ongoing research in computational design synthesis of passive dynamic systems aims to automatically generate robotic configurations based on a given task. However, an automated design-to-fabrication process also requires a flexible fabrication method. This paper aims to explore designing and fabricating passive dynamic walking robots and all necessary components using single-material fused deposition modeling (FDM). Being able to fabricate all components of a robot using FDM is a step toward the goal of automated design and fabrication of passive dynamic robots. Design/methodology/approach Two different configurations of passive dynamic walking robots are re-designed to be fabricated using FDM. Different robotic joint assemblies are designed and tested. To arrive at feasible solutions, a modular design approach is chosen and adjustability of components after printing is integrated in the design. Findings The suitability of FDM for printing passive dynamic robots is shown to depend heavily on the sensitivity of the configuration. For one robot configuration, all components are printed in one job and only little assembly is needed after printing. For the second robot configuration, which has a more sensitive gait, a metal bearing is found to increase the performance substantially. Originality/value Printable, monolithic mechatronic systems require multi-material printing, including electronics. In contrast, passive dynamic systems not only have the potential to save energy and component cost compared to actuated systems but can also be fabricated using single-material FDM as demonstrated in this paper.

Influence of the swing ankle angle on walking stability for a passive dynamic walking robot with flat feet

To achieve high walking stability for a passive dynamic walking robot is not easy. In this article, we aim to investigate whether the walking performance for a passive dynamic walking robot can be improved by just simply changing the swing ankle angle before impact. To validate this idea, a passive bipedal walking model with two straight legs, two flat feet, a hip joint, and two ankle joints was built in this study. The walking dynamics that contains double stance phase was derived. By numerical simulation of the walking in MATLAB, we found that the walking performance can be adjusted effectively by only simply changing the swing ankle angle before impact. A bigger swing ankle angle in a reasonable range will lead to a higher walking stability and a lower initial walking speed of the next step. A bigger swing ankle angle before impact leads to a bigger amount of energy lost during impact for the quasi-passive dynamic walking robot which will influence the walking stability of the next step.

重心位置変化による受動的動歩行ロボットの歩幅の制御

重心位置変化による受動的動歩行ロボットの歩幅の制御

Level-Ground Walking for 3D Quasi-Passive Walker with Flat Feet - Lateral-plane Input using McKibben-Type Artificial Muscle -

Currently, many bipedal robots have been proposed to realize the high energy efficiency walking. The passive dynamic walking does not require control input. Generally, a foot of passive dynamic walking robot is an arc foot. In this paper, it is intended to establish a control method and control mechanism to achieve energy efficient and stable gate. Therefore, we developed 3D quasi-passive walker with flat feet driven by an antagonistic pneumatic artificial muscle. An antagonistic mechanism is constituted by a pair of McKibben muscle. And an antagonistic pneumatic system is used as joint actuators of linkage mechanisms which control the torque, joint stiffness and position simultaneously. Finally, this report shows that the 3D quasi-passive walking in the level ground can realize by the swinging (simple) input of the frontal direction, and the stride of the robot is proportional to lateral-plane input.

System overview and walking dynamics of a passive dynamic walking robot with flat feet

The concept of “passive dynamic walking robot” refers to the robot that can walk down a shallow slope stably without any actuation and control which shows a limit cycle during walking. By adding actuation at some joints, the passive dynamic walking robot can walk stably on level ground and exhibit more versatile gaits than fully passive robot, namely, the “limit cycle walker.” In this article, we present the mechanical structures and control system design for a passive dynamic walking robot with series elastic actuators at hip joint and ankle joints. We built a walking model that consisted of an upper body, knee joints, and flat feet and derived its walking dynamics that involve double stance phases in a walking cycle based on virtual power principle. The instant just before impact was chosen as the start of one step to reduce the number of independent state variables. A numerical simulation was implemented by using MATLAB, in which the proposed passive dynamic walking model could walk stably down a shallow slope, which proves that the derived walking dynamics are correct. A physical passive robot prototype was built finally, and the experiment results show that by only simple control scheme the passive dynamic robot could walk stably on level ground.

Bifurcations and chaos in passive dynamic walking: A review

Irrespective of achieving certain success in comprehending Passive Dynamic Walking (PDW) phenomena from a viewpoint of the chaotic dynamics and bifurcation scenarios, a lot of questions still need to be answered. This paper provides an overview of the previous literature on the chaotic behavior of passive dynamic biped robots. A review of a broad spectrum of chaotic phenomena found in PDW in the past is presented for better understanding of the chaos detection and controlling methods. This paper also indicates that the bulk of literature on PDW robots is focused on locomotion on slope, but there is a thriving trend towards bipedal walking in more challenging environments.

2A1-H06 対称構造を有する受動的動歩行ロボット(受動歩行ロボット(1))

Passive Dynamic Walking robots' structures which are used in previous researches usually generate different gaits for every step because of the robots' structures. However, general system model of Passive Dynamic Walking which is used for the research generates uniform gait for every step, of course. For this reason, it is desirable for the real prototyped legged walking robots to generate uniform gaits which are used for Passive Dynamic Walking research. For this reason, we proposed a new symmetric structure of Passive Dynamic Walking robot which generates uniform gait for every step. In this paper we describe the robot's structure and walking behavior in detail.

1A1-J05 スリップ時における二足歩行ロボットの制御と回復性(進化・学習とロボティクス)

Passive Dynamic Walking is a technique that makes a robot walk naturally like a human adjusting to skews and slight slopes without active control or energy. It is energy efficient, but to set the initial condition for robots to walk stably is difficult. So when a Passive Dynamic Walking model is affected by a slip, it is not considered to walk stably. This paper analyzes how the gait stability of Passive Dynamic Walking robots is affected by a slip. The results of this study provide some ideas about how to apply such technique in a variety of environments or conditions.

Modeling and Control of Passive Dynamic Walking Robot with Humanoid Gait

Considering the sagittal movement and the lateral swing in the humanoid practical walking, a new humanoid passive dynamic bipedal robot with the lateral movable upper body is proposed in this paper. The finite state machine (FSM) theory is adopted to control the robot, which changes agilely the control strategy according to the practical states of the humanoid gait. In the method, the torque compensation adaptive excitation control strategy is used for sagittal control and PID is applied to the upper body for the robots lateral stability. It is verified by the co-simulation based on ADAMS and MATLAB that the bipedal robot can reach the stable humanoid gait with the high energy efficiency.

Switch Control between Different Speeds for a Passive Dynamic Walker

To make a biped robot walk stably at various speeds, a novel switch control approach is proposed to make the gaits switch smoothly between different walking speeds. The switch controller is designed based on the Lyapunov stability theory and the sufficient condition is given to make the closed-loop system stable. This controller can allow the robot to reach the stable gaits corresponding to the various speeds and improve the robustness of switch process. Potential energy compensation control has been studied in the dynamic model of a passive dynamic walking robot with knees. The functional relationship between the initial states and the walking speed is obtained. Numerical simulations are provided to verify the effectiveness of the control strategy.

2A2-Q04 超多脚型受動的動歩行ロボットJenkka-IIIの実機検証(受動歩行ロボット)

A Passive Dynamic Walking robot can walk down a gentle slope naturally without any actuator or controller, only using potential energy. This suggests that the principle of walking may exist in this phenomenon. Current researches have confirmed Passive Dynamic Walking (PDW) for biped and quadruped. However, it is also important and interesting to study PDW for more than six legs because it could be a significant approach for the resolution of the principle of walking. In this research, the super multilegged passive dynamic walking robot was analyzed by experiments with " Jenkka-III". And it was confirmed that the 20 legged robot could walk and its gait was changed depending on the degree of freedom of its bodies.

2A2-Q02 四脚受動的動歩行における胴体要素の影響に関する研究(受動歩行ロボット)

A passive dynamic walking robot can walk down a gentle slope naturally without any actuator or controller, only by potential energy. Therefore, it is thought that the principle of walking exists in this phenomenon. By current researches, the passive dynamic walking has been confirmed for 2,4,and more than 6 legs. In the previous research, it was verified that a body of multi legged Passive Dynamic walker affected its gaits. In this research, the effect of body element of a quadrupedal Passive Dynamic Walking robot was analyzed in more detail on a simulator.

2P1-E07 受動歩行の安定足形状を用いた歩行安定化補助靴の開発(福祉ロボティクス・メカトロニクス(1))

2P1-E07 受動歩行の安定足形状を用いた歩行安定化補助靴の開発(福祉ロボティクス・メカトロニクス(1))

D12 上半身を有する準受動的二足歩行ロボットの製作と解析(D1ロボット制御)

D12 上半身を有する準受動的二足歩行ロボットの製作と解析(D1ロボット制御)

2A2-Q10 歩行時の状態量が測定可能な受動的動歩行ロボットの開発 : 実験による歩行動作の安定解析(受動歩行ロボット)

In this paper we propose a compass type passive dynamic walking robot which has sensors to measure its dynamical parameters to analyze its walking gaits and behavior. A typical compass type walking robot has a difficulty to keep on walking because of its structure; the outer leg and the inner leg have same length, so the swing leg strikes its foot to the ground during its walking. To improve the problem we develop a new mechanism which expand and contract the second thigh part of the legs, and contribute to cut off the impact shock of ground contact. And then we investigate the behavior of Passive Dynamic Walking by the logged data of the robot.

2A2-E20 受動的動歩行の原理を利用した脚式歩行ロボットの開発

It is well-known that Passive dynamic walking robots walk efficiently, however, the robots are not able to walk on the level ground. Therefore we try to develop a semi-passive dynamic walking robot which can walk on the level ground by adding torques of ankle region using the property of Passive dynamic walking. In this paper we report a simulation result which indicates semi-passive dynamic walking realization.

2A2-F08 歩容解析のための膝付受動的動歩行ロボットの開発

In this paper we report about our development of a passive dynamic walking robot with knees which can measure state-parameters such as angles of knees and hips, posture, grounding contact. And we also show its experimental results and effectiveness.

2A2-F03 上半身を有する準受動的二足歩行ロボットの製作と解析

In this paper, we have developed a new mini quasi passive dynamic walking robot with an upper body. This robot is controlled by delayed feedback which can stabilize periodic walking orbits without their exact information. Then, the parameters of the mini robot are determined based on the numerical simulation in which quasi passive dynamic walking of the mini robot is analyzed. Moreover, we have shown in this paper the mechanism of the mini robot and the experimental result.