Study on feet forces' distributions, energy consumption and dynamic stability measure of hexapod robot during crab walking

Mahapatra, Abhijit; Roy, Shibendu Shekhar; Pratihar, Dilip Kumar

doi:10.1016/j.apm.2018.09.015

Cited by 23 publications

(16 citation statements)

References 52 publications

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“…The main body of the UMSWR and swing leg have an uninterrupted and continuous motion for the given initial position and orientation. Hence, it is assumed that the motions are regulated by a step function that approximates the Heaviside step function with a cubic polynomial [64]. Effective gait planning and an efficient algorithm is required to move the robot's legs in a sequential manner along a straight path on various terrains.…”

Section: Path Planning For Optimized Drag and Posture Adjustment Techmentioning

confidence: 99%

Concept Design of the Underwater Manned Seabed Walking Robot

Khan

Wang

et al. 2019

JMSE

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In this paper, a novel concept designed of a multi-legged underwater manned seabed walking robot is presented. The robot will be used in both shallow water current (1–2 m/sec) and deep water up to 500 m. It is powered by an external electric power source through tether cable. It walks on the seabed with six legs, which makes it distinct from conventional screw-propelled underwater robots. It can walk calmly without making the water turbid. Two anterior arms act as manipulators. All leg joints and manipulators are controlled by Brushless Direct Current Motors. Motivation for this concept comes from soldier crab that walk mostly forward and has an egg-shaped body. It is operated by a pilot sitting in a pressurized cabin, and promptly control operations of the robot and manipulator. Preliminary design of the pressurized cabin, using an empirical formula, “ASME PVHO-1 2007” standard, and validation was carried out through ANSYS Workbench. Hydrodynamic forces acting on the robot body and legs are utilized to withstand the water current and external forces to adjust legs and body posture for stability. Buoyancy rules are employed to control its rising and diving motion. All key technologies employed in the development of the robot and their approaching methods are explained. It will provide a safe operation space for humans in underwater operations.

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Section: Path Planning For Optimized Drag and Posture Adjustment Techmentioning

confidence: 99%

Concept Design of the Underwater Manned Seabed Walking Robot

Khan

Wang

et al. 2019

JMSE

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“…Assuming that the robot is loaded, the center of gravity of the body remains unchanged, and the body can be kept horizontal and static by adjusting the foot position of the supporting leg. The contact of the foot tip with the ground can be modeled as a hard point contact with friction, which indicates that the interaction between the foot tip and the ground is limited to three force components [24], as shown in the enlarged portion of Figure 1. Force f iz is in the vertical direction, and forces f ix and f iy are in the ground direction.…”

Section: Static Analysismentioning

confidence: 99%

Research on Low Energy Consumption Static Postures of Bionic Feet

Zhang

Gao

et al. 2019

Applied Sciences

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By studying the relation of the robot’s postures and its energy consumption, a static analysis-based method to obtain the low-energy postures of the robot is proposed. This method decreases the energy consumption and increases the battery life by adjusting the postures in the horizontal environment. The method takes the low-speed hexapod bionic robot as the research object. First, we obtain the output torque of each joint of the leg through static analysis and establish the energy consumption model of the robot. Considering the flexibility of the robot, we then introduce the performance index of the maximum step length and establish an equilibrium solution based on energy consumption and maximum step size. Finally, we derive the low-energy postures of the robot using MATLAB (MATLAB 2014a, The MathWorks, Natick, Massachusetts State, USA, 2014) simulations. An energy consumption experiment is carried out with a physical prototype to verify the validity of the method.

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“…A previous study by Mahapatra et al 42 tackled the coupled dynamic problem, whereby the coupling effect of the swing legs on support legs was addressed. However, the validation of such dynamic model using virtual prototyping (VP) tools and experiments is very much essential.…”

Section: Introductionmentioning

confidence: 99%

“…However, the validation of such dynamic model using virtual prototyping (VP) tools and experiments is very much essential. The present study deals with the validation of the developed model 42 (both experimentally and MSC ADAMS simulation) on a six-legged robot either maneuvering on flat terrains or climbing a staircase, prescribing swing leg trajectory in 3D Cartesian space and tackling the coupled multi-body dynamics. In addition to validation, the present study examines the accuracy with which a nonlinear, constrained inverse dynamical model of the six-legged robot could consider the coupling effects of swing legs on the support legs and trunk body, and with which a proposed 3D foot-ground interaction mechanics model (deformable foot on hard terrain with little deformation) could represent compliance between the foot and ground during locomotion on staircase or flat terrains.…”

Section: Introductionmentioning

confidence: 99%

“…Also, the dynamic model has been further improved in the present study by incorporating the calculation of moment arm for the determination of moment at foot-tip. The previous study by Mahapatra et al 42 assumed the moment arm to be equal to zero in the case studies. Furthermore, it is to be noted that although the basic equations are the same as that of Mahapatra et al, 42 in the present study, the terrains are different, and therefore, there are significant changes in the formulation and boundary conditions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Optimal Feet-Forces’ and Torque Distributions of Six-Legged Robot Maneuvering on Various Terrains

Mahapatra¹,

Roy

Pratihar

2019

Robotica

Self Cite

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SUMMARYAn analytical model with coupled dynamics for a realistic six-legged robotic system locomoting on various terrains has been developed, and its effectiveness has been proven through computer simulations and validated using virtual prototyping tools and real experiment. The approach is new and has not been attempted before. This study investigated the optimal feet-forces’ distributions under body force and foot–ground interaction considering compliant contact and friction force models for the feet undergoing slip. The kinematic model with 114 implicit constraints in 3D Cartesian space has been transformed in terms of generalized coordinates with a reduced explicit set of 24 constrained equations using kinematic transformations. The nonlinear constrained inverse dynamics model of the system has been formulated as a coupled dynamical problem using Newton–Euler method with realistic environmental conditions (compliant foot–ground contact, impact, and friction) and computed using optimization techniques due to its indeterminate nature. One case study has been carried out to validate the analytical data with the simulated ones executed in MSC.ADAMS® (Automated Dynamic Analysis of Mechanical Systems), while the other case study has been conducted to validate the analytical and simulated data with the experimental ones. In both these cases, results are found to be in close agreement, which proves the efficacy of the model.

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Study on feet forces' distributions, energy consumption and dynamic stability measure of hexapod robot during crab walking

Cited by 23 publications

References 52 publications

Concept Design of the Underwater Manned Seabed Walking Robot

Concept Design of the Underwater Manned Seabed Walking Robot

Research on Low Energy Consumption Static Postures of Bionic Feet

Optimal Feet-Forces’ and Torque Distributions of Six-Legged Robot Maneuvering on Various Terrains

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