scholarly journals Control of a Biped Robot by Total Rate of Angular Momentum Using the Task Function Approach

2005 ◽  
Vol 2 (2) ◽  
pp. 111-116
Author(s):  
J. A. Rojas-Estrada ◽  
J. Marot ◽  
P. Sardain ◽  
G. Bessonnet
Keyword(s):  
Angular Momentum ◽  
Control Problem ◽  
Degrees Of Freedom ◽  
Biped Robot ◽  
Function Approach ◽  
Control Law ◽  
Total Rate ◽  
Biped Robots ◽  
Formal Problem

In this work we address the control problem of biped robots by using the task function approach. A problem arrives when one of the feet is in contact with the ground, which presents imperfections. There is then the possibility that the biped robot undergoes a fall. It is difficult to track any trajectory due to the presence of unevenness on the ground. What we propose is to use the task function approach combined with the application of the total rate of angular momentum to obtain a control law for the ankle. By this technique, the tracking becomes more smooth and the balance is assured. The control law proposed allows the upper part of the robot to be controlled independently since only the ankle actuators are concerned. We enounce the formal problem and present some simulations with real parameters of a 21 degrees of freedom biped robot.

scholarly journals Control of a biped robot by total rate of angular momentum using the task function approach

2005 ◽  
Vol 2 (2) ◽  
pp. 111-116
Author(s):  
J. A. Rojas-Estrada ◽  
J. Marot ◽  
P. Sardain ◽  
G. Bessonnet
Keyword(s):  
Angular Momentum ◽  
Biped Robot ◽  
Function Approach ◽  
Total Rate

Design of a Biped Robot With Torsion Springs at the Joints for Reduced Energy Consumption During Walk

2009 ◽  
Author(s):  
Santosh Pratap Singh ◽  
Ashish Dutta ◽  
Anupam Saxena
Keyword(s):  
Energy Consumption ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Biped Robot ◽  
Single Step ◽  
Biped Robots ◽  
Gait Parameters ◽  
Reduction Of Energy Consumption ◽  
Torsion Springs ◽  
Spring Constants

Biped robots have multiple degrees of freedom for walking and hence they consume a lot of energy. In this paper it is proposed that adding torsion springs at the joints of an 8 DOF biped will lead to reduced energy consumption during walk. First the dynamic equations of motion of the biped robot are obtained incorporating the torsion springs at the joints. Using the dynamic model the total energy consumed during walk was evaluated for a single step. A Genetic Algorithm (GA) based algorithm was developed for finding the energy optimal trajectory during gait by comparing all the possible trajectories. It is first proved that addition of torsion springs at the joints lead to reduction of energy consumption as compared to a biped with no springs. All the gait parameters were then optimized to get the optimum values for the spring constants at each joint, reference angle of springs and length of each step. It is proved that using these optimal parameters the proposed biped robot consumes the least energy.

scholarly journals Triple-Mode Model Predictive Control Using Future Target Information

Processes ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 54
Author(s):  
Minghao Chen ◽  
Zuhua Xu ◽  
Jun Zhao
Keyword(s):  
Model Predictive Control ◽  
Control Problem ◽  
Predictive Control ◽  
Degrees Of Freedom ◽  
Golden Section ◽  
Tracking Performance ◽  
Control Law ◽  
Target Information ◽  
The Future ◽  
Triple Mode

In this paper, we propose a triple-mode model predictive control (MPC) algorithm that uses future target information to improve tracking performance. To explicitly take into account the future target information in the MPC optimization, the proposed triple-mode control law encompasses three parts: (i) the future target information feedforward, (ii) the output feedback, and (iii) the extra degrees of freedom for constraint satisfaction. The first two parts of the control law are off-line designed through unconstrained MPC, and the optimal future trajectory horizon is obtained by golden section search based on the integral of squared error (ISE) criterion. The final part is calculated by the on-line MPC algorithm aiming to satisfy constraints. Furthermore, we analyze the feasibility and convergence properties of the proposed algorithm. The method is demonstrated by the simulation of the shell fundamental control problem and also tested on the coordinated control problem in the power plant. The test results show that the proposed algorithm can increase tracking performance dramatically due to the proper selection of future trajectory horizon.

Design of a Biped Toy Robot with an Automatic Center of Gravity Shifting Mechanism

2010 ◽  
Vol 118-120 ◽  
pp. 670-674
Author(s):  
Pai Shan Pa ◽  
Jinn Bao Jou
Keyword(s):  
Degrees Of Freedom ◽  
Biped Robot ◽  
Center Of Gravity ◽  
Biped Robots ◽  
Zero Moment Point ◽  
Single Motor ◽  
Mechanical Products ◽  
Zero Moment ◽  
Crank Mechanism

The design of the biped toy robot in this study, presents a brand new concept compared to that of the conventional mechanical biped robots on the market. These conventional mechanical products rely mainly on a large sole area to stabilize the wobbling movement during walking. In this design walking stability is not achieved by large sole areas, but by having more degrees of freedom and automatically shifting the center of gravity as the robot walks. A single motor is used to drive the biped toy robot trunk so that the center of gravity is automatically shifted to achieve walking stability. The two feet are driven by four connecting rods for striding and leg-lifting action. More particularly, an equal parallel crank mechanism is provided that uses a single motor to drive the connecting rods, thereby swinging the center of gravity of the toy robot in time with striding frequency. In addition, the concept of the zero moment point is utilized in the shifting of the center of gravity allowing the biped robot to lift its legs, change step, and move forward in balance. This study also discusses the use of the four connecting rods, and the shifting of the center of gravity of the robot, as an alternative to the servomotors commonly used in conventional robots which are bulky, expensive and hard to control.

Bibot-U6: A Novel 6-DoF Biped Active Walking Robot - Modeling, Planning and Control

2014 ◽  
Vol 11 (02) ◽  
pp. 1450014 ◽  
Author(s):  
Xuefeng Zhou ◽  
Yisheng Guan ◽  
Haifei Zhu ◽  
Wenqiang Wu ◽  
Xin Chen ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Biped Robot ◽  
High Energy ◽  
Walking Robots ◽  
Walking Robot ◽  
Biped Robots ◽  
Planning And Control ◽  
Biped Walking Robot ◽  
And Control ◽  
High Energy Consumption

Most of current biped robots are active walking platforms. Though they have strong locomotion ability and good adaptability to environments, they have a lot of degrees of freedom (DoFs) and hence result in complex control and high energy consumption. On the other hand, passive or semi-passive walking robots require less DoFs and energy, but their walking capability and robustness are poor. To overcome these shortcomings, we have developed a novel active biped walking robot with only six DoFs. The robot is built with six 1-DoF joint modules and two wheels as the feet. It achieves locomotion in special gaits different from those of traditional biped robots. In this paper, this novel biped robot is introduced, four walking gaits are proposed, the criterion of stable walking is addressed and analyzed, and walking patterns and motion planning are presented. Experiments are carried out to verify the locomotion function, the effectiveness of the presented gaits and to illustrate the features of this novel biped robot. It has been shown that biped active walking may be achieved with only a few DoFs and simple kinematic configuration.

The Design of Central Pattern Generators Based on the Matsuoka Oscillator to Generate Rhythmic Human-Like Movement for Biped Robots

2007 ◽  
Vol 11 (8) ◽  
pp. 946-955 ◽  
Author(s):  
Guang Lei Liu ◽  
◽  
Maki K. Habib ◽  
Keigo Watanabe ◽  
Kiyotaka Izumi
Keyword(s):  
Degrees Of Freedom ◽  
Central Pattern Generators ◽  
Biped Robot ◽  
Coupling Coefficients ◽  
Neuron Models ◽  
Bipedal Robots ◽  
Biped Robots ◽  
Coupling Dynamics ◽  
Pattern Generators ◽  
6 Degrees Of Freedom

We propose a controller based on a central pattern generator (CPG) network of mutually coupled Matsuoka nonlinear neural oscillators to generate rhythmic human-like movement for biped robots. The parameters of mutually inhibited and coupled Matsuoka oscillators and the necessary interconnection coupling coefficients within the CPG network directly influence the generation of the required rhythmic signals related to targeted motion. Our objective is to analyze the mutually coupled neuron models of Matsuoka oscillators to realize an efficient CPG design that leads to have dynamic, stable, sustained rhythmic movement with robust gaits for bipedal robots. We discuss the design of a CPG model with new interconnection coupling links and its inhibitation coefficients for a CPG-based controller. The new design was studied through interaction between simulated interconnection coupling dynamics with six links and a musculoskeletal model with the 6 degrees of freedom (DOFs) of a biped robot. We used the weighted outputs of mutually inhibited oscillators as torques to actuate joints. We verified the effectiveness of our proposal through simulation and compared the results to those of Taga’s CPG model, confirming better, more efficient generation of stable rhythmic walking at different speeds and robustness in response to disturbances.

Dynamics Synchronization of the Running of Planar Biped Robots With SLIP Model in Stance Phase

2014 ◽  
Author(s):  
Behnam Dadashzadeh ◽  
Mohammad Mahjoob Jahromi
Keyword(s):  
Stance Phase ◽  
Lagrange Equation ◽  
Center Of Mass ◽  
Biped Robot ◽  
Control Law ◽  
Slip Model ◽  
Initial State ◽  
Biped Robots ◽  
Model Dynamics ◽  
Vast Literature

In this work a control law is derived to synchronize dynamics of multibody biped robots and the spring loaded inverted pendulum (SLIP) model in stance phase of running. The goal is to use the vast literature on the SLIP model dynamics for the control of real multibody robots. Three kneed biped robot models are considered in this work: with springs parallel to motors, with springs series to motors, and without springs. Dynamic equations of the multibody biped models are derived using Lagrange equation and then the applicability of the derived control law to these models are investigated using simulation. The initial state of the multibody robot is found such that its center of mass (CoM) has the same initial condition as SLIP model. Then the trajectory of its CoM is compared to SLIP model. Also motor torque profiles are compared for the models with and without springs and also for the motors with and without rotor inertias. The results show that the effect of rotor inertia is a big challenge in implementing fast biped running on real robots.

Modeling and Simulation of a Novel 16-DOF Humanoid Biped Robot

2012 ◽  
Author(s):  
C. Hernández-Santos ◽  
E. Rodriguez-Leal ◽  
R. Soto ◽  
J. L. Gordillo
Keyword(s):  
Degrees Of Freedom ◽  
Biped Robot ◽  
Human Gait ◽  
Forward Kinematics ◽  
Kinematics And Dynamics ◽  
Lagrangian Dynamics ◽  
Biped Robots ◽  
Kinematic Chains ◽  
Body Parameters ◽  
The Mathematical Model

Humanoid biped robots are typically complex in design, having numerous degrees-of-freedom (DOF) due to the ambitious goal of mimicking the human gait. This paper presents the forward kinematics and dynamics of a new sixteen DOF humanoid biped robot. The synthesis of the kinematic chains is based on human body parameters in terms of ratios, range of motion, and physical length. The paper proposes a new architecture for a biped robot with seven DOF per each leg, adding one DOF that imitates the toe joint. The dynamic model is approached by dividing the legs into the sagittal and frontal planes, which simplifies the mathematical model by further applying the principle of Lagrangian dynamics. The paper contains several simulations and numerical examples to prove the analytical results.

Sliding Mode Control of Underactuated Biped Robots

2005 ◽  
Author(s):  
Mehdi Nikkhah ◽  
Hashem Ashrafiuon ◽  
Farbod Fahimi
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Biped Robot ◽  
Control Law ◽  
Robust Tracking Control ◽  
Biped Robots ◽  
Control Approach ◽  
Double Support ◽  
Mode Control ◽  
The Impact

This paper presents a robust tracking control algorithm for underactuated biped robots. The biped considered in this work is modeled as a five-link planar robot with four actuators located at hip and knee joints to control the joint angles. The control law is defined based on the sliding mode control approach. The objective of the controller is to generate stable walking based on predefined desired trajectories. The planning of the trajectory in swing phase is discussed while the double support phase is considered to be instantaneous and the impact of the swing leg with the ground is modeled as rigid body contact. In order to formulate the sliding control law, we define four first-order sliding surfaces, based on the number of actuators, as a linear combination of tracking joint positions and velocities. The control approach is shown to guarantee that all trajectories will reach and stay on these surfaces. The surface parameters are then selected to ensure the stability of the surfaces leading to an asymptotically stable control law. Numerical simulation is presented for tracking a multi-step walk of a biped robot.

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.

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