Omnidirectional Static Walking of a Quadruped Robot on a Slope

2006 ◽  
Vol 18 (1) ◽  
pp. 51-58
Author(s):  
Lei Zhang ◽  
◽  
Shugen Ma ◽  
Yoshinori Honda ◽  
Kousuke Inoue ◽  
...  
Keyword(s):  
Stability Margin ◽  
Static Stability ◽  
Quadruped Robot ◽  
Body Posture ◽  
Gait Transition ◽  
Minimum Number ◽  
Motion Speed ◽  
Arbitrary Body ◽  
Time Required ◽  
Foot Position

We propose successive gait transition with arbitrary body posture to enable a quadruped robot to walk statically and omnidirectionally on a slope. Body posture is determined by rotation around 3 axes, roll, pitch, and yaw. Successive gait transition with a minimum number of steps on a slope is realizable using common foot position before and after gait transition. The time required to transit between gaits is reduced by carefully designing foot position in crawling and rotating while limiting foot reachable region on a slope. The robot thus walks into any direction with arbitrary body postures. In this study, we also verify a tradeoff relation between motion speed and body posture. Computer simulation and experiments verified the feasibility of our proposed method and the stability of gait transition based on static stability margin.

Structural design and gait research of a new bionic quadruped robot

2021 ◽  
pp. 095440542199566
Author(s):  
Jiu-Peng Chen ◽  
Hong-Jun San ◽  
Xing Wu ◽  
Bin-Zhou Xiong
Keyword(s):  
Stability Margin ◽  
Static Stability ◽  
Quadruped Robot ◽  
Superior Performance ◽  
Linkage Mechanism ◽  
Wide Range ◽  
Planning Algorithm ◽  
Planning Experiment ◽  
Strength And Stiffness ◽  
Foot Trajectory

Quadruped bionic robot has a strong adaptability to the environment, compared with wheeled and tracked robots, it has superior motion performance, and has a wide range of application prospects in rescue and disaster relief, ground mine clearance, mountain transportation, so it has become a research hotspot all over the world. Leg structure is an important embodiment of the superior performance of quadruped robot, and it is also the key and difficult point of design. This article proposes a novel quadruped robot with waist structure, which can complete a variety of gait forms. Based on the theory of linkage mechanism, a novel leg structure is designed with anti-parallelogram mechanism, which improves the strength and stiffness of the robot. Using D-H description method, the kinematics analysis of this quadruped robot single leg is carried out. On this basis, in order to ensure the foot contact with the ground and achieve zero impact, polynomial programming is used to plan the foot trajectory of swing phase and support phase. Based on the static stability margin, the optimal static gait of the quadruped robot is planned. A co-simulation study has been carried out to investigate further the validity and effectiveness of the quadruped robot on gait. The simulation results clearly show the robot can walk steadily and its input and output meet the expected requirements. The solid prototype platform is built, and the trajectory planning experiment of single leg is carried out, and the foot trajectory of single leg is obtained by using laser tracker. The gait planning algorithm is applied to the whole robot, and the results show that the robot can walk according to the scheduled gait, which proves the effectiveness of the proposed algorithm.

Optimal turning gait of a six-legged robot using a GA-fuzzy approach

2000 ◽  
Vol 14 (3) ◽  
pp. 207-219 ◽  
Author(s):  
DILIP KUMAR PRATIHAR ◽  
KALYANMOY DEB ◽  
AMITABHA GHOSH
Keyword(s):  
Stability Margin ◽  
Static Stability ◽  
Legged Robot ◽  
Fuzzy Approach ◽  
Traditional Methods ◽  
Gait Generation ◽  
Minimum Number ◽  
Stable Gait ◽  
Multilegged Robot ◽  
The Stability

This paper describes a new method for generating the turning-gait of a six-legged robot using a combined genetic algorithm (GA)-Fuzzy approach. The main drawback of the traditional methods of gait generation is their high computational load. Thus, there is still a need for the development of a computationally tractable algorithm that can be implemented online to generate stable gait of a multilegged robot. In the proposed genetic-fuzzy system, the fuzzy logic controllers (FLCs) are used to generate the stable gait of a hexapod and a GA is used to improve the performance of the FLCs. The effectiveness of the proposed algorithm is tested on a number of turning-gait generation problems of a hexapod that involve translation as well as rotation of the vehicle. The hexapod will have to take a sharp circular turn (either clockwise or counter-clockwise) with minimum number of ground legs having the maximum average kinematic margin. Moreover, the stability margin should lie within a certain range to ensure static stability of the vehicle. Each leg of a six-legged robot is controlled by a separate FLC and the performance of the controllers is improved by using a GA. It is to be noted that the actual optimization is done off-line and the hexapod can use these optimized FLCs to navigate in real-world scenarios. As an FLC is computationally less expensive, the proposed algorithm will be faster compared with the traditional methods of gait-generation, which include both graphical as well as analytical methods. The GA-tuned FLCs are found to perform better than the author-defined FLCs.

Gait Planning of Quadruped Robot Walking on a Slope Based on Static Balance

2013 ◽  
Vol 373-375 ◽  
pp. 282-286 ◽  
Author(s):  
Wen Yu Zhang ◽  
Lei Zhang
Keyword(s):  
Center Of Pressure ◽  
Quadruped Robot ◽  
Joint Torque ◽  
Static Balance ◽  
Gait Transition ◽  
Gait Planning ◽  
Motion Speed ◽  
Walking Environment ◽  
Movement Parameters ◽  
The Stability

Gait planning affects stability, motion speed, and joint torque of quadruped robot etc. Also, it is necessary to consider movement parameters of slope walking environment such as the inclination angle, the movement area of feet and so on. The stability criterion on the basis of center of pressure is chosen to analyze the stability during the movement. Based on static balance, the omni-directional walking of quadruped robot on a slope is planned. CFP is set in order to reduce the transition steps. Then the start and end positions of swinging leg and supporting leg is calculated. The process of gait transition is planned to make sure stable and continuous movement. The experiment verifies the validity of the proposed method.

Walking Stability Analysis of Multi-Legged Crablike Robot over Slope

2013 ◽  
Vol 572 ◽  
pp. 636-639
Author(s):  
Xi Chen ◽  
Gang Wang
Keyword(s):  
Mathematical Model ◽  
Stability Analysis ◽  
Stability Criterion ◽  
Stability Margin ◽  
Static Stability ◽  
Matlab Simulation ◽  
And Performance ◽  
The Stability ◽  
The Mathematical Model ◽  
The Relationship

This paper deals with the walking stability analysis of a multi-legged crablike robot over slope using normalized energy stability margin (NESM) method in order to develop a common stabilization description method and achieve robust locomotion for the robot over rough terrains. The robot is simplified with its static stability being described by NESM. The mathematical model of static stability margin is built so as to carry out the simulation of walking stability over slope for the crablike robot that walks in double tetrapod gait. As a consequence, the relationship between stability margin and the height of the robots centroid, as well as its inclination relative to the ground is calculated by the stability criterion. The success and performance of the stability criterion proposed is verified through MATLAB simulation and real-world experiments using multi-legged crablike robot.

scholarly journals Analysis and experiments with a 3D printed walking robot to improve climbing obstacle

2020 ◽  
Vol 17 (3) ◽  
pp. 172988142092528
Author(s):  
Ivan Chavdarov ◽  
Aleksandar Krastev ◽  
Bozhidar Naydenov ◽  
Galia Pavlova
Keyword(s):  
Mobile Robots ◽  
Static Stability ◽  
Walking Robot ◽  
Baseline Model ◽  
Minimum Number ◽  
3D Printed ◽  
Different Shapes ◽  
Original Concept

The purpose of this work is to investigate the possibilities of climbing higher obstacles while maintaining the overall dimensions of a walking robot through design improvements and experiments. An original concept for the design of a walking robot with a minimum number of motors is presented. Geometric and force constraints for overcoming an obstacle and the conditions for maintaining static stability are determined. Experiments for overcoming a vertical obstacle are conducted with a 3D printed model. The 3D printed robot feet with different shapes and materials are used. The results of the experiments are presented graphically as a percentage of success against a baseline model. In this study, a dimensionless index to compare the height of the overcome obstacle and the dimensions of the robot is introduced. It allows to objectively compare the possibilities of overcoming obstacles between various types of mobile robots. Conclusions and guidelines for design improvements are made.

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.

Multifractal characteristics of combustor dynamics close to lean blowout

2015 ◽  
Vol 784 ◽  
pp. 30-50 ◽  
Author(s):  
Vishnu R. Unni ◽  
R. I. Sujith
Keyword(s):  
Stability Margin ◽  
Static Stability ◽  
Combustion Noise ◽  
Stable Operation ◽  
Nonlinear Behaviour ◽  
Classical Literature ◽  
Unified Framework ◽  
Simple Description ◽  
Thermoacoustic Instability ◽  
Lean Blowout

In classical literature, blowout is described as loss of static stability of the combustion system whereas thermoacoustic instability is seen as loss of dynamic stability of the system. At blowout, the system transitions from a stable reacting state to a non-reacting state, indicating loss of static stability of the reaction. However, this simple description of stability margin is inadequate since recent studies have shown that combustors exhibit complex nonlinear behaviour prior to blowout. Recently, it was shown that combustion noise that characterizes the regime of stable operation is itself dynamically complex and exhibits multifractal characteristics. Researchers have already described the transition from combustion noise to combustion instability as a loss of multifractality. In this work, we provide a multifractal description for lean blowout in combustors with turbulent flow and thus introduce a unified framework within which both thermoacoustic instability and blowout can be described. Further, we introduce a method for predicting blowout based on the multifractal description of blowout.

Sign in / Sign up

Export Citation Format

Share Document