scholarly journals Dynamic Modeling and Nonlinear Position Control of a Quadruped Robot with Theo Jansen Linkage Mechanisms and a Single Actuator

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Shunsuke Nansai ◽  
Rajesh Elara Mohan ◽  
Ning Tan ◽  
Nicolas Rojas ◽  
Masami Iwase
Keyword(s):  
Dynamic Modeling ◽  
Position Control ◽  
Equations Of Motion ◽  
Load Ratio ◽  
Quadruped Robot ◽  
Legged Robot ◽  
Modeling And Analysis ◽  
Quadruped Robots ◽  
Scalable Design ◽  
First Time

The Theo Jansen mechanism is gaining widespread popularity among the legged robotics community due to its scalable design, energy efficiency, low payload-to-machine-load ratio, bioinspired locomotion, and deterministic foot trajectory. In this paper, we perform for the first time the dynamic modeling and analysis on a four-legged robot driven by a single actuator and composed of Theo Jansen mechanisms. The projection method is applied to derive the equations of motion of this complex mechanical system and a position control strategy based on energy is proposed. Numerical simulations validate the efficacy of the designed controller, thus setting a theoretical basis for further investigations on Theo Jansen based quadruped robots.

Analysis of the Energy Loss on Quadruped Robot Having a Flexible Trunk Joint

2017 ◽  
Vol 29 (3) ◽  
pp. 536-545
Author(s):  
Masahiro Ikeda ◽  
◽  
Ikuo Mizuuchi
Keyword(s):  
Energy Loss ◽  
Energy Flow ◽  
Control Method ◽  
Quadruped Robot ◽  
Rough Terrain ◽  
Legged Robot ◽  
Walking Robot ◽  
Passive Joint ◽  
Quadruped Robots ◽  
The Relationship

[abstFig src='/00290003/09.jpg' width='300' text='Energy flow in legged robot' ] As a method of robot movement, legs have the advantage of traversability on rough terrain. However, the motion of a legged robot is accompanied by energy loss. The main causes for this loss could be negative work and contact between the legs and ground. On the other hand, animals with legs are considered to reduce energy loss by using the elasticity of their body. In this study, we analyze the influence of walking, using an elastic passive joint mounted on the trunk of a quadruped robot, on the energy loss. Additionally, we study the energy flow between legs and elastic components. In this study, we clarify a control method for quadruped robots in order to reduce the energy loss of walking. The results of simulating a quadruped walking robot, which has passive joints with elastic components on the trunk, are analyzed and the relationship between each kind of energy loss and the trunk joint’s elasticity is clarified.

scholarly journals Modeling and Analysis on Energy Consumption of Hydraulic Quadruped Robot for Optimal Trot Motion Control

2019 ◽  
Vol 9 (9) ◽  
pp. 1771 ◽  
Author(s):  
Kun Yang ◽  
Xuewen Rong ◽  
Lelai Zhou ◽  
Yibin Li
Keyword(s):  
Energy Consumption ◽  
Motion Control ◽  
Spline Interpolation ◽  
Heat Rate ◽  
Step Length ◽  
Quadruped Robot ◽  
Modeling And Analysis ◽  
Quadruped Robots ◽  
Gait Parameters ◽  
Height Step

Energy consumption is an important performance index of quadruped robots. In this paper, the energy consumptions of the quadruped robot SCalf with a trot gait under different gait parameters are analyzed. Firstly, the kinematics and dynamics models of the robot are established. Then, an energy model including the mechanical power and heat rate is proposed. To obtain the energy consumption, a cubic spline interpolation foot trajectory is used, and the feet forces are calculated by using the minimization of norm of the foot force method. Moreover, an energetic criterion measuring the energy cost is defined to evaluate the motion. Finally, the gait parameters such as step height, step length, standing height, gait cycle, and duty cycle that influence the energy consumption are studied, which could provide a theoretical basis for parameter optimization and motion control of quadruped robots.

scholarly journals Creeping Gait Analysis and Simulation of a Quadruped Robot

2019 ◽  
Vol 14 (2) ◽  
pp. 93-106
Author(s):  
Firas A. Raheem ◽  
Murtadha Khudhair Flayyih
Keyword(s):  
Sequence Analysis ◽  
Gait Analysis ◽  
Inverse Kinematic ◽  
Quadruped Robot ◽  
Legged Robot ◽  
Stability Margins ◽  
Robot Locomotion ◽  
Quadruped Robots ◽  
Kinematic Models ◽  
The Stability

A quadruped (four-legged) robot locomotion has the potential ability for using in different applications such as walking over soft and rough terrains and to grantee the mobility and flexibility. In general, quadruped robots have three main periodic gaits:  creeping gait, running gait and galloping gait. The main problem of the quadruped robot during walking is the needing to be statically stable for slow gaits such as creeping gait. The statically stable walking as a condition depends on the stability margins that calculated particularly for this gait. In this paper, the creeping gait sequence analysis of each leg step during the swing and fixed phases has been carried out. The calculation of the minimum stability margins depends upon the forward and inverse kinematic models for each 3-DOF leg and depends on vertical geometrical projection during walking. Simulation and results verify the stability insurance after calculation the minimum margins which indicate clearly the robot COG (Center of Gravity) inside the supporting polygon resulted from the leg-tips.

scholarly journals Modeling and analysis on low energy consumption foot trajectory for hydraulic actuated quadruped robot

2021 ◽  
Vol 18 (6) ◽  
pp. 172988142110620
Author(s):  
Yaru Sun ◽  
Zisen Hua ◽  
Yibin Li ◽  
Chai Hui ◽  
Xianhua Li ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Gait Cycle ◽  
Simulation Analysis ◽  
Spline Interpolation ◽  
Quadruped Robot ◽  
Hydraulic Actuator ◽  
Total Energy Consumption ◽  
Modeling And Analysis ◽  
Quadruped Robots ◽  
Foot Trajectory

According to the energy consumption characteristics of hydraulic actuator, the valuable foot trajectory characterized by using segmented cubic spline interpolation curve in the swing phase is proposed firstly to reduce the energy consumption of quadruped robots, which is implemented by using controlling parameters tf to change the duration of leg raising and falling in one gait cycle, and then realized the directly control to the time ratio between the piston extension and retraction. Then, the total energy consumption of the hydraulic actuated quadruped robot SCalf-II is modeled. Meanwhile, the parameters of the foot trajectory that have a large impact on the energy consumption are determined. Finally, simulation analysis and verification experiments of the robot moving with constant speeds at the key parameters are performed. The results show that for the given foot trajectory, the optimization ranges of the gait cycle and duration of leg lifting from the lowest to highest are determined in which the energy required for the robot locomotion is at a relatively low level.

Fault-tolerant control of a compliant legged quadruped robot for free swinging failure

2017 ◽  
Vol 232 (2) ◽  
pp. 161-177 ◽  
Author(s):  
Mehul M Gor ◽  
PM Pathak ◽  
AK Samantaray ◽  
Jung Ming Yang ◽  
SW Kwak
Keyword(s):  
Dynamic Modeling ◽  
Control Strategy ◽  
External Load ◽  
Fault Tolerant ◽  
Bond Graph ◽  
Quadruped Robot ◽  
Quadruped Robots ◽  
Hazardous Environments ◽  
Critical Issues ◽  
Robot Body

Quadruped robots are designed to work in remote or hazardous environments which are unreachable or harmful for humans. In these situations, reliability and adaptability are the most critical issues for the quadruped robot. During the failure of any actuator, the performance of quadruped robot is severely affected. The failure can lead to joint locking or free joint. In the case of free joint, leg joint loses actuator torque and also the capability to support the robot body on the ground. Leg joint also loses resistance to external load and acts as a free rotating hanging link. This article presents strategies for controlling a compliant legged quadruped robot in the presence of free swinging failure. The strategy is motivated by the natural crawling by infants and adapted crawling by persons with specific disabilities. Bond graph has been used for dynamic modeling of the system. The control strategy has been tested both through simulations and experiments conducted on a prototype quadruped robot.

Dynamic Modeling and Analysis for a Planar Three Degrees-of-Freedom Manipulator Under Prescribed Mount Motion

2019 ◽  
Author(s):  
Takeyuki Ono ◽  
Ryosuke Eto ◽  
Junya Yamakawa ◽  
Hidenori Murakami
Keyword(s):  
Dynamic Modeling ◽  
Degrees Of Freedom ◽  
Sliding Mode ◽  
Virtual Work ◽  
Equations Of Motion ◽  
Base Plate ◽  
Moving Frame ◽  
Parallel Plates ◽  
Modeling And Analysis ◽  
Three Degrees Of Freedom

Abstract This paper presents dynamic modeling of a planar, three degrees-of-freedom manipulator consisting of two parallel plates, referred to as top and base plates, which are connected by three actuated legs. When a sensitive equipment is carried by a moving robot or vehicle, it becomes necessary to mount the equipment on a platform which achieves precise positioning for stabilization. The objectives of this paper are to derive analytical equations of motion and apply them to control simulations on the stabilizing planar manipulator. In the derivation of analytical equations of motion, the moving frame method is utilized to describe the kinematics of the two-dimensional multibody system. For the manipulator system comprised of jointed bodies, a graph tree is utilized, which visually illustrates how the constituent bodies are connected to each other. For kinetics, the principle of virtual work is employed to derive the analytical equations of motion for the manipulator system. The resulting equations of motion are used to numerically assess the performance of a sliding mode controller (SMC) to stabilize the top plate from the motion of the translating and rotating base plate. In the numerical simulation, the SMC is compared with a simple PID controller to evaluate both the tracking performance and robustness.

Preventing Tumbling With a Twisting Trunk for the Quadruped Robot: Origaker I

2018 ◽  
Author(s):  
Chunsong Zhang ◽  
Xuheng Chai ◽  
Jian S. Dai
Keyword(s):  
Line Segment ◽  
Quadruped Robot ◽  
Center Of Gravity ◽  
Stability Criteria ◽  
Trunk Motion ◽  
Quadruped Robots ◽  
Direct Motion ◽  
First Time ◽  
The Relationship

The tumble stability indicates the capability to resist the tumble caused by disturbances. For a quadruped robot, the tumble is mainly about the line segment connecting two supporting feet. The tumble stability of quadruped robots is evaluated by various stability criteria based on forces, moments or energies. Work has been done to improve the tumble stability of quadruped robots. Nevertheless, the previous work to achieve this goal relied on motion of legs. No trunk motions were considered. As a matter of fact, trunk motion is widely utilized by natural quadrupeds. By utilizing trunk motion, the quadrupeds are able to regulate the center of gravity to improve the tumble stability level. This paper for the first time investigates the effect of the twisting trunk on the tumble stability of quadruped robots from the viewpoint of energy. Thus it can be seen that the twisting trunk help improve the tumble stability level of quadruped robots. The relationship between the tumble stability and trunk twisting is to be analyzed mathematically, and help find the maximum disturbing energy that the quadruped robot can bear with a twisting trunk and further direct motion of the trunk twisting during tumbles to prevent any overturning.

Dynamic Modeling and Analysis of Three-Dimensional Slack Cables With Application to Elevator Traveling Cables

2015 ◽  
Author(s):  
W. D. Zhu ◽  
Y. G. Mao ◽  
G. X. Ren
Keyword(s):  
Dynamic Modeling ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Beam Theory ◽  
Differential Algebraic Equations ◽  
Dynamic Responses ◽  
Algebraic Equations ◽  
Differentiation Formula ◽  
Modeling And Analysis ◽  
Rayleigh Beam

This paper addresses three-dimensional dynamic modeling of a moving elevator traveling cable with bending and torsional stiffnesses and arbitrarily moving ends. An absolute nodal coordinate formulation based on Rayleigh beam theory is introduced to model the traveling cable. Dynamic equations of motion, which are presented as differential algebraic equations, are solved by the backward differentiation formula. Equilibria of a traveling cable with different cable parameters and car positions are first calculated. Motions of cable ends are prescribed next to simulate the free response of the traveling cable due to motion of the car. Finally, effects of different types of building sways on dynamic responses of the traveling cable are examined.

Dynamic Modeling and Analysis of an Axially Moving and Spinning Rayleigh Beam Based on a Time-varying Element

2021 ◽  
Author(s):  
Shuai Yang ◽  
ajun Hu ◽  
Guidong Mo ◽  
Xingwang Zhang ◽  
Junjie Qin ◽  
...  
Keyword(s):  
Dynamic Modeling ◽  
Time Varying ◽  
Modeling And Analysis ◽  
Rayleigh Beam ◽  
Axially Moving
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