A novel online gait optimization approach for biped robots with point-feet

2019 ◽  
Vol 25 ◽  
pp. 81
Author(s):  
Majid Anjidani ◽  
M.R. Jahed Motlagh ◽  
M. Fathy ◽  
M. Nili Ahmadabadi
Keyword(s):  
Learning Algorithm ◽  
Biped Robot ◽  
Optimization Method ◽  
Optimization Approach ◽  
Loop Model ◽  
Modeling Error ◽  
Environment Change ◽  
Biped Robots ◽  
Walking Gait ◽  
New Situation

Designing a stable walking gait for biped robots with point-feet is stated as a constrained nonlinear optimization problem which is normally solved by an offline numerical optimization method. On the result of an unknown modeling error or environment change, the designed gait may be ineffective and an online gait improvement is impossible after the optimization. In this paper, we apply Generalized Path Integral Stochastic Optimal Control to closed-loop model of planar biped robots with point-feet which leads to an online Reinforcement Learning algorithm to design the walking gait. We study the ability of the proposed method to adapt the controller of RABBIT, which is a planar biped robot with point-feet, for stable walking. The simulation results show that the method, starting a dynamically unstable initial gait, quickly compensates the modeling error and reaches to a walking with exponential stability and desired features in a new situation which was impossible by the past methods.

scholarly journals Comparative stable walking gait optimization for small-sized biped robot using meta-heuristic optimization algorithms

2018 ◽  
Vol 40 (4) ◽  
pp. 407-424
Author(s):  
Tran Thien Huan ◽  
Ho Pham Huy Anh
Keyword(s):  
Humanoid Robot ◽  
Differential Evolution Algorithm ◽  
Biped Robot ◽  
The Novel ◽  
Biped Robots ◽  
Walking Gait ◽  
Gait Parameters ◽  
Lift Height ◽  
Evolution Algorithm ◽  
Gait Optimization

This paper proposes a new way to optimize the biped walking gait design for biped robots that permits stable and robust stepping with pre-set foot lifting magnitude. The new meta-heuristic CFO-Central Force Optimization algorithm is initiatively applied to optimize the biped gait parameters as to ensure to keep biped robot walking robustly and steadily. The efficiency of the proposed method is compared with the GA-Genetic Algorithm, PSO-Particle Swarm Optimization and Modified Differential Evolution algorithm (MDE). The simulated and experimental results carried on the prototype small-sized humanoid robot demonstrate that the novel meta-heuristic CFO algorithm offers an efficient and stable walking gait for biped robots with respect to a pre-set of foot-lift height value.

scholarly journals How does ankle push-off balance the walking speed and energy efficiency of planar biped robots?

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110119
Author(s):  
Qiaoli Ji ◽  
Zhihui Qian ◽  
Lei Ren ◽  
Luquan Ren
Keyword(s):  
Energy Efficiency ◽  
Gait Cycle ◽  
Walking Speed ◽  
Biped Robot ◽  
Step Length ◽  
Cost Of Transport ◽  
Biped Robots ◽  
Walking Gait ◽  
Motion Performance ◽  
Step Transition

Ankle push-off is defined as the phase in which muscle-tendon units about the ankle joint generate a burst of positive power during the step-to-step transition in human walking. The dynamic walking of a biped robot can be effectively realized through ankle push-off. However, how to use ankle push-off to balance the walking speed and energy efficiency of biped robots has not been studied deeply. In this study, the effects of the step length (the inter-leg angle is 40°, 50°, and 60°), torque and timing of ankle push-off on the walking speed and energy efficiency of biped robots were studied. The results show that when the step length is 50°, the push-off torque is 30 N· m and the corresponding push-off timing occurs at 43% of the gait cycle, the simulated robot obtains a highly economical walking gait. The corresponding maximum normalized walking speed is 0.40, and the minimum mechanical cost of transport is 2.25. To acquire a more economical walking gait of biped robots, the amount of ankle push-off and the push-off timing need to be coordinated. The purpose of this study is to provide a reference for the influence of ankle push-off on the motion performance of biped robots.

The Experimental Study of the Influence of the Foot Articulated Structure on the Biped Robot Walking

2013 ◽  
Vol 461 ◽  
pp. 924-929
Author(s):  
Xiao Chun Hu ◽  
Xiao Peng Li ◽  
Qing Qing Zhang ◽  
Bao Zhao ◽  
Qin Xia
Keyword(s):  
Biped Robot ◽  
Body Motion ◽  
Human Walking ◽  
Future Research ◽  
Bionic Design ◽  
Biped Robots ◽  
Walking Gait ◽  
Comparison Results ◽  
Foot Deformation ◽  
Support Phase

Abstract: Purpose：By investigating the variation of the human walking gait kinematics with respect to the foot deformation constraint, prove that bionic design of feet are the necessity for biped robots to imitate human walking better in terms of flexibility, stability and efficiency. The results will be significant for future research and development of biped robots. Methods: A human being was assumed as a perfect biped robot which had ideal motion drive and control. The walking gait parameters of two healthy men with foot deformation unconstrained and constrained were tested respectively by the inertia motion capture suit, and then they were processed by programming and analyzed by comparison. Results: The data analysis showed that when subjects walked with foot deformation constrained, their angular displacements of lower limb joints generally increased, the curves of angular velocity and accelerations fluctuated in certain walking phases, the walking pace and stride length decreased obviously, the single support phase shortened while the double support phase lengthened. At the same time, subjects felt subjectively that their body motion was less flexible, the walking posture was difficult to control, and the walking stability was more strenuous to keep. Conclusion: Combining the logical analogies with the detailed experimentation results, it is inferred that biped robots with rigid feet will have to suffer awkward and unstable walking gait, heavier and strenuous steps, and lower energy efficiency while walking. The paper concludes the necessity of bionic design of the robot feet for improving the walking quality of the biped robots. The conclusion and the experiment data will be of significant value for future work of robot design and evaluation.

scholarly journals Arms Swing Effects on a Walking Planar Biped

2012 ◽  
Author(s):  
Bassel Kaddar ◽  
Yannick Aoustin ◽  
Christine Chevallereau
Keyword(s):  
Energy Consumption ◽  
Parametric Optimization ◽  
Energy Criterion ◽  
Biped Robot ◽  
Optimization Method ◽  
Robot Kinematics ◽  
Kinematics And Dynamics ◽  
Flat Foot ◽  
Walking Gait ◽  
One Step

A walking gait is designed for a planar biped with two identical three-link legs, a trunk and two one-link arms. This nine-link biped is controlled via eight torques to obtain one step of a cyclic gait. The scope of this paper is to investigate the effects of arms swing on the energy consumption during walking of a fully actuated planar biped robot. Kinematics and dynamics of a biped, HYDROID, are used for this study. Desired gaits are considered to be cyclic having single support phases separated by flat foot impacts. Different evolutions of the arms: arms held, arms bound and arms swing are compared. For each case, we use a parametric optimization method with constraints to produce reference cyclic trajectories according to an energy criterion. The numerical results show that this criterion is lower in the case where the arms swing.

Torso pitch motion effects on walking gait for biped robots

2021 ◽  
pp. 1-11
Author(s):  
Long Li ◽  
Zhongqu Xie ◽  
Xiang Luo ◽  
Juanjuan Li ◽  
Yufeng He
Keyword(s):  
Energy Consumption ◽  
Biped Robot ◽  
Gait Pattern ◽  
Optimization Criterion ◽  
Pattern Generation ◽  
Biped Robots ◽  
Unit Distance ◽  
Pitch Motion ◽  
Walking Gait ◽  
Gait Parameters

Gait pattern generation has an important influence on the walking quality of biped robots. In most gait pattern generation method, it is usually assumed that the torso remains vertial during walking. It is very intuitive and simple. However, is the gait pattern of keeping the torso vertical the most efficient? This paper presents a gait pattern in which the torso has pitch motion during walking. We define the cyclic gait of a seven-link biped robot with multiple gait parameters. The gait parameters are determined by optimization. The optimization criterion is choosen to minimize the energy consumption per unit distance of the biped robot. In order to compare the energy consumption of the proposed gait pattern with the one of torso vertical gait pattern, we generate two sets of optimal gait with various walking step lengths and walking periods. The results show that the proposed gait pattern is more energy-efficiency than the torso vertical gait pattern.

The Application of the Combination of Monte Carlo Optimization Method based QSAR Modeling and Molecular Docking in Drug Design and Development

2020 ◽  
Vol 20 (14) ◽  
pp. 1389-1402 ◽  
Author(s):  
Maja Zivkovic ◽  
Marko Zlatanovic ◽  
Nevena Zlatanovic ◽  
Mladjan Golubović ◽  
Aleksandar M. Veselinović
Keyword(s):  
Monte Carlo ◽  
Molecular Docking ◽  
Computer Calculation ◽  
Molecular Graph ◽  
Optimization Method ◽  
Docking Studies ◽  
Optimization Approach ◽  
Qsar Modeling ◽  
Monte Carlo Optimization ◽  
Molecular Docking Studies

In recent years, one of the promising approaches in the QSAR modeling Monte Carlo optimization approach as conformation independent method, has emerged. Monte Carlo optimization has proven to be a valuable tool in chemoinformatics, and this review presents its application in drug discovery and design. In this review, the basic principles and important features of these methods are discussed as well as the advantages of conformation independent optimal descriptors developed from the molecular graph and the Simplified Molecular Input Line Entry System (SMILES) notation compared to commonly used descriptors in QSAR modeling. This review presents the summary of obtained results from Monte Carlo optimization-based QSAR modeling with the further addition of molecular docking studies applied for various pharmacologically important endpoints. SMILES notation based optimal descriptors, defined as molecular fragments, identified as main contributors to the increase/ decrease of biological activity, which are used further to design compounds with targeted activity based on computer calculation, are presented. In this mini-review, research papers in which molecular docking was applied as an additional method to design molecules to validate their activity further, are summarized. These papers present a very good correlation among results obtained from Monte Carlo optimization modeling and molecular docking studies.

scholarly journals Effects of Torso Pitch Motion on Energy Efficiency of Biped Robot Walking

2021 ◽  
Vol 11 (5) ◽  
pp. 2342
Author(s):  
Long Li ◽  
Zhongqu Xie ◽  
Xiang Luo ◽  
Juanjuan Li
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Biped Robot ◽  
Gait Pattern ◽  
Pattern Generation ◽  
Biped Robots ◽  
Pitch Motion ◽  
Double Support ◽  
Gait Parameters ◽  
Support Phase

Gait pattern generation has an important influence on the walking quality of biped robots. In most gait pattern generation methods, it is usually assumed that the torso keeps vertical during walking. It is very intuitive and simple. However, it may not be the most efficient. In this paper, we propose a gait pattern with torso pitch motion (TPM) during walking. We also present a gait pattern with torso keeping vertical (TKV) to study the effects of TPM on energy efficiency of biped robots. We define the cyclic gait of a five-link biped robot with several gait parameters. The gait parameters are determined by optimization. The optimization criterion is chosen to minimize the energy consumption per unit distance of the biped robot. Under this criterion, the optimal gait performances of TPM and TKV are compared over different step lengths and different gait periods. It is observed that (1) TPM saves more than 12% energy on average compared with TKV, and the main factor of energy-saving in TPM is the reduction of energy consumption of the swing knee in the double support phase and (2) the overall trend of torso motion is leaning forward in double support phase and leaning backward in single support phase, and the amplitude of the torso pitch motion increases as gait period or step length increases.

Stochastic Bayesian optimization for predicting borderline knock

2021 ◽  
pp. 146808742110652
Author(s):  
Jian Tang ◽  
Anuj Pal ◽  
Wen Dai ◽  
Chad Archer ◽  
James Yi ◽  
...  
Keyword(s):  
Fuel Economy ◽  
Learning Algorithm ◽  
Feedforward Control ◽  
Model Development ◽  
Kriging Model ◽  
Optimization Method ◽  
Surrogate Models ◽  
Bayesian Optimization ◽  
Control Parameters ◽  
Operation Conditions

Engine knock is an undesirable combustion that could damage the engine mechanically. On the other hand, it is often desired to operate the engine close to its borderline knock limit to optimize combustion efficiency. Traditionally, borderline knock limit is detected by sweeping tests of related control parameters for the worst knock, which is expensive and time consuming, and also, the detected borderline knock limit is often used as a feedforward control without considering its stochastic characteristics without compensating current engine operational condition and type of fuel used. In this paper, stochastic Bayesian optimization method is used to obtain a tradeoff between stochastic knock intensity and fuel economy. The log-nominal distribution of knock intensity signal is converted to Gaussian one using a proposed map to satisfy the assumption for Kriging model development. Both deterministic and stochastic Kriging surrogate models are developed based on test data using the Bayesian iterative optimization process. This study focuses on optimizing two competing objectives, knock intensity and indicated specific fuel consumption using two control parameters: spark and intake valve timings. Test results at two different operation conditions show that the proposed learning algorithm not only reduces required time and cost for predicting knock borderline but also provides control parameters, based on trained surrogate models and the corresponding Pareto front, with the best fuel economy possible.

scholarly journals Online Biped Walking Pattern Generation with Contact Consistency

2015 ◽  
Vol 4 (1) ◽  
pp. 19
Author(s):  
Wenqi Hou ◽  
Jian Wang ◽  
Jianwen Wang ◽  
Hongxu Ma
Keyword(s):  
Biped Robot ◽  
Gait Pattern ◽  
Pattern Generation ◽  
Task Space ◽  
Biped Walking ◽  
Foot Placement ◽  
Walking Gait ◽  
Walking Pattern ◽  
Generating Method ◽  
Stable Periodic

In this paper, a novel online biped walking gait pattern generating method with contact consistency is proposed. Generally, it’s desirable that there is no foot-ground slipping during biped walking. By treating the hip of the biped robot as a linear inverted pendulum (LIP), a foot placement controller that takes the contact consistency into account is proposed to tracking the desired orbit energy. By selecting the hip’s horizontal locomotion as the parameter, the trajectories in task space for walking are planned. A task space controller without calculating the inversion of inertial matrix is presented. Simulation experiments are implemented on a virtual 5-link point foot biped robot. The results show the effectiveness of the walking pattern generating method which can realize a stable periodic gait cycle without slipping and falling even suffering a sudden disturbance.

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