scholarly journals Self-Stabilising Quadrupedal Running by Mechanical Design

2009 ◽  
Vol 6 (1) ◽  
pp. 73-85 ◽  
Author(s):  
Panagiotis Chatzakos ◽  
Evangelos Papadopoulos
Keyword(s):  
Mechanical System ◽  
Mechanical Design ◽  
Quadruped Robot ◽  
The Self ◽  
Rough Terrain ◽  
Stable Regime ◽  
Quadruped Robots ◽  
The Stability ◽  
Running Robots ◽  
Body Inertia

Dynamic stability allows running animals to maintain preferred speed during locomotion over rough terrain. It appears that rapid disturbance rejection is an emergent property of the mechanical system. In running robots, simple motor control seems to be effective in the negotiation of rough terrain when used in concert with a mechanical system that stabilises passively. Spring-like legs are a means for providing self-stabilising characteristics against external perturbations. In this paper, we show that a quadruped robot could be able to perform self-stable running behaviour in significantly broader ranges of forward speed and pitch rate with a suitable mechanical design, which is not limited to choosing legs spring stiffness only. The results presented here are derived by studying the stability of the passive dynamics of a quadruped robot running in the sagittal plane in a dimensionless context and might explain the success of simple, open loop running controllers on existing experimental quadruped robots. These can be summarised in (a) the self-stabilised behaviour of a quadruped robot for a particular gait is greatly related to the magnitude of its dimensionless body inertia, (b) the values of hip separation, normalised to rest leg length, and leg relative stiffness of a quadruped robot affect the stability of its motion and should be in inverse proportion to its dimensionless body inertia, and (c) the self-stable regime of quadruped running robots is enlarged at relatively high forward speeds. We anticipate the proposed guidelines to assist in the design of new, and modifications of existing, quadruped robots. As an example, specific design changes for the Scout II quadruped robot that might improve its performance are proposed.

Stability Margin of a Metamorphic Quadruped Robot With a Twisting Trunk

2019 ◽  
Vol 11 (6) ◽  
Author(s):  
Chunsong Zhang ◽  
Chi Zhang ◽  
Jian S. Dai ◽  
Peng Qi
Keyword(s):  
Closed Loop ◽  
Stability Margin ◽  
Rigid Bodies ◽  
Quadruped Robot ◽  
Quadruped Robots ◽  
Kinematic Performance ◽  
The Stability ◽  
Twisting Angle

Abstract To date, most quadruped robots are either equipped with trunks that are rigid bodies or consist of blocks connected by passive joints. The kinematic performance of these quadruped robots is only determined by their legs. To release the mobility of trunks and enhance the performance of quadruped robots, this paper proposes a metamorphic quadruped robot with a moveable trunk (a planar six-bar closed-loop linkage), called MetaRobot I, which can implement active trunk motions. The robot can twist its trunk like natural quadrupeds. Through trunk twisting, the stability margin of the quadruped robot can be increased compared with that of a quadruped robot with a rigid trunk. The inner relationship between the stability margin and the twisting angle is analyzed in this paper. Finally, simulations are carried out to show the benefits facilitated by the twisting trunk to the quadruped robot.

Normalized Energy Stability Margin Based Analysis of Omni-Directional Static Walking of a Quadruped Robot on Rough Terrain

2011 ◽  
Vol 383-390 ◽  
pp. 7401-7405
Author(s):  
Lei Zhang ◽  
Shan Gao
Keyword(s):  
Stability Criterion ◽  
Simulation Experiment ◽  
Stability Margin ◽  
Quadruped Robot ◽  
Center Of Gravity ◽  
Energy Stability ◽  
Rough Terrain ◽  
The Stability

With Normalized Energy Stability Margin(Sne ) as stability criterion, this paper studies the tumbles of omni-directional static walking of a quadruped robot around the line connecting two adjacent supporting legs on rough terrain, proposes the method to improve the stability of quadruped robot by increasing the (Sne ) value, which is realized by lowering the height of center of gravity(COG), and finally substantiates the feasibility of the method through a simulation experiment.

scholarly journals Echo State Networks for Estimating Exteroceptive Conditions From Proprioceptive States in Quadruped Robots

2021 ◽  
Vol 15 ◽  
Author(s):  
Mario Calandra ◽  
Luca Patanè ◽  
Tao Sun ◽  
Paolo Arena ◽  
Poramate Manoonpong
Keyword(s):  
Mechanical Design ◽  
Sensory System ◽  
Quadruped Robot ◽  
Proprioceptive Information ◽  
Reservoir Computing ◽  
Quadruped Robots ◽  
Echo State Networks ◽  
Dynamic Estimation ◽  
Reaction Forces ◽  
Computing Structure

We propose a methodology based on reservoir computing for mapping local proprioceptive information acquired at the level of the leg joints of a simulated quadruped robot into exteroceptive and global information, including both the ground reaction forces at the level of the different legs and information about the type of terrain traversed by the robot. Both dynamic estimation and terrain classification can be achieved concurrently with the same reservoir computing structure, which serves as a soft sensor device. Simulation results are presented together with preliminary experiments on a real quadruped robot. They demonstrate the suitability of the proposed approach for various terrains and sensory system fault conditions. The strategy, which belongs to the class of data-driven models, is independent of the robotic mechanical design and can easily be generalized to different robotic structures.

Gait Planning and Simulation Analysis of a New Amphibious Quadruped Robots

2018 ◽  
Vol 30 (2) ◽  
pp. 257-264
Author(s):  
Shuo Han ◽  
◽  
Yuan Chen ◽  
Guangying Ma ◽  
Jinshan Zhang ◽  
...  
Keyword(s):  
Simulation Analysis ◽  
Stability Margin ◽  
Quadruped Robot ◽  
Working Environment ◽  
Practical Application ◽  
Quadruped Robots ◽  
Driving Mechanisms ◽  
Adams Software ◽  
New Type ◽  
The Stability

In order to allow quadruped robots to adapt to the complex working environment in the field of fisheries and aquaculture, a new type of quadruped robot with linear and rotary driving is proposed, and the kinematic inverse solution of the leg of the quadruped robot is deduced. For achieving quadruped robot smooth walking, the straight gait of the quadruped robot is planned according to the stability margin principle of motion, so that the stability margin of the machine is 20 mm when three legs supporting it. The planning gait is simulated by ADAMS software, the kinematics and dynamics analysis of the four main driving mechanisms of the robot leg were carried out, and the feasibility of using the STEP5 driving function to execute the planning gait in the quadruped robot was verified. The theoretical and simulation curve analysis results show that, the quadruped robot according to the planned gait can complete the cycle and have a stable walking. The results of this study can provide a reference for the practical application of the new amphibious quadruped robot in the fields of complex and uneven ground in the field of fisheries and aquaculture to realize exploration, fishing and transportation.

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 Stability Criterion for Dynamic Gaits of Quadruped Robot

2018 ◽  
Vol 8 (12) ◽  
pp. 2381 ◽  
Author(s):  
Yan Jia ◽  
Xiao Luo ◽  
Baoling Han ◽  
Guanhao Liang ◽  
Jiaheng Zhao ◽  
...  
Keyword(s):  
Dynamic Stability ◽  
Stability Criterion ◽  
Quadruped Robot ◽  
Stability Criteria ◽  
Irregular Terrain ◽  
Quadruped Robots ◽  
Simulation Results ◽  
Zero Moment ◽  
The Stability ◽  
Dynamic Gait

Dynamic-stability criteria are crucial for robot’s motion planning and balance recovery. Nevertheless, few studies focus on the motion stability of quadruped robots with dynamic gait, none of which have accurately evaluated the robots’ stability. To fill the gaps in this field, this paper presents a new stability criterion for the motion of quadruped robots with dynamic gaits running over irregular terrain. The traditional zero-moment point (ZMP) is improved to analyze the motion on irregular terrain precisely for dynamic gaits. A dynamic-stability criterion and measurement are proposed to determine the stability state of the robot and to evaluate its stability. The simulation results show the limitations of the existing stability criteria for dynamic gaits and indicate that the criterion proposed in this paper can accurately and efficiently evaluate the stability of a quadruped robot using such gaits.

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 Automated Quadruped Robot Simulation using Internet of Things and MATLAB

2021 ◽  
Vol 2115 (1) ◽  
pp. 012022
Author(s):  
Richik Ray ◽  
Rishita Shanker ◽  
Harsh Gupta ◽  
Mohit Sharan ◽  
Swagatika Mohanty
Keyword(s):  
Internet Of Things ◽  
Damage Control ◽  
Quadruped Robot ◽  
Quadruped Robots ◽  
Simulink Model ◽  
Current Consumption ◽  
Cloud Server ◽  
Key Factor ◽  
Computer Based ◽  
The Stability

Abstract In this paper, a MATLAB Simulink model of a Quadruped Robot is presented alongside its remote, control and monitor user interface that has been developed by using the fundamentals of Internet of Things on a Node-Red Flow and the FRED-Cloud Server. Robotics and Automation over the recent years have developed exponentially and hence have been a key factor in the rise of Industry 4.0 which has usurped manual supervision and operation in industrial and manufacturing processes around the globe. The design and creation of technologically advanced robots integrated with computer-based software for their automation has not only successfully made the tasks facile to manage within short spans of time, but also has increased the efficiency notably. The stability and mobility of quadruped robots is considered to be ideal on differing terrains with minimal subtle changes, thereby making it an asset. Internet of Things on the other hand, has paved its way over the control of robots as well, with its unparalleled benefits. This paper is focused on the design and execution of the Quadiuped model which includes the observation of the various significant graphs achieved post simulation with respect to electrical values such as power and current consumption, and a visual animation of the robot running in the workspace. Furthermore, a single platform is developed and displayed that allows a user to log in for security puiposes and thereby, operate and monitor the functions and conditions of the bot easily, ranging from remote visual support, directional integrity, damage control and more, without the need of multiple platforms to carry out varying tasks with respect to control.

Robust Dynamic Locomotion Through Feedforward-Preflex Interaction

2000 ◽  
Author(s):  
Jorge G. Cham ◽  
Sean A. Bailey ◽  
Mark R. Cutkosky
Keyword(s):  
Mechanical System ◽  
Elastic Properties ◽  
Sensory Feedback ◽  
Motor Pattern ◽  
Robotic Systems ◽  
Reflex Response ◽  
Rough Terrain ◽  
Uncertain Environments ◽  
Control Hypothesis ◽  
Running Robots

Abstract Unlike most legged robotic systems built to date, even simple animals have the ability to quickly and robustly traverse through rough terrain and over large obstacles and gaps. Recent evidence from insect physiology research indicates that arthropods achieve this fast robust locomotion largely without relying on sensory feedback or reflex response. Instead, locomotion is the result of the interaction between a basic feedforward motor pattern and the visco-elastic properties of the mechanical system, termed “preflexes.” In this paper, we consider the implications of this control hypothesis for the design of small running robots for uncertain environments. We present working prototypes that show how robust dynamic locomotion can be achieved without the use of sensory feedback. We then discuss modeling approaches for these kinds of systems and present results from simulations of representative models.

scholarly journals Single-Leg Structural Design and Foot Trajectory Planning for a Novel Bioinspired Quadruped Robot

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Mingfang Chen ◽  
Qi Li ◽  
Sen Wang ◽  
Kaixiang Zhang ◽  
Hao Chen ◽  
...  
Keyword(s):  
Structural Design ◽  
Control Algorithm ◽  
Quadruped Robot ◽  
Rational Structure ◽  
Flight Phase ◽  
Experimental Platform ◽  
Quadruped Robots ◽  
The Stability ◽  
The Impact ◽  
Foot Trajectory

To meet the stability requirements for moving quadruped robots, it is important to design a rational structure for a single leg and plan the trajectory of the foot. First, a novel electrically driven leg mechanism for a quadruped robot is designed in this paper to reduce the inertia of the leg swing. Second, a modified foot trajectory based on a compound cycloid is proposed, which has swing-back and retraction motion and continuous velocity in the x-axis direction. Third, a Simulink platform is built to verify the correctness of the proposed foot trajectory. The simulation result shows that when the flight phase and the stand phase switch, the impact of torque is smaller than the foot trajectory before modification. Finally, an experimental platform is constructed, and a control algorithm is written into the controller to realize the foot proposed trajectory. The results of the experiment prove the feasibility of the leg mechanism and the rationality of the proposed foot trajectory.

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