Biped Landing Pattern Modification Method and Walking Experiments in Outdoor Environment

2008 ◽  
Vol 20 (5) ◽  
pp. 775-784 ◽  
Author(s):  
Kenji Hashimoto ◽  
◽  
Yusuke Sugahara ◽  
Hun-Ok Lim ◽  
Atsuo Takanishi ◽  
...  
Keyword(s):  
Biped Robot ◽  
Stability Control ◽  
Outdoor Environment ◽  
Walking Robots ◽  
Control Algorithms ◽  
Biped Robots ◽  
Uneven Terrain ◽  
Walking Pattern ◽  
Actual Compliance ◽  
Modification Method

Many researchers have studied walking stability control for biped robots, most of which involve highly precise acceleration controls based on robot model mechanics. Modeling error, however, makes the control algorithms used difficult to apply to biped walking robots intended to transport human users. The “landing pattern modification method” we propose is based on nonlinear admittance control. Theoretical compliance displacement calculated from walking patterns is compared to actual compliance displacement, when a robot's foot contacts slightly uneven terrain. Terrain height is detected and the preset walking pattern is modified accordingly. The new biped foot we also propose forms larger support polygons on uneven terrain than conventional biped foot systems do. Combining our new modification method and foot, a human-carrying biped robot can traverse uneven terrain, as confirmed in walking experiments.

scholarly journals Constrained Quadratic Programming and Neurodynamics-Based Solver for Energy Optimization of Biped Walking Robots

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Liyang Wang ◽  
Ming Chen ◽  
Xiangkui Jiang ◽  
Wei Wang
Keyword(s):  
Energy Consumption ◽  
Quadratic Programming ◽  
Energy Optimization ◽  
Biped Robot ◽  
High Energy ◽  
Walking Robots ◽  
Biped Robots ◽  
Biped Walking ◽  
Joint Torques ◽  
Force Moment

The application of biped robots is always trapped by their high energy consumption. This paper makes a contribution by optimizing the joint torques to decrease the energy consumption without changing the biped gaits. In this work, a constrained quadratic programming (QP) problem for energy optimization is formulated. A neurodynamics-based solver is presented to solve the QP problem. Differing from the existing literatures, the proposed neurodynamics-based energy optimization (NEO) strategy minimizes the energy consumption and guarantees the following three important constraints simultaneously: (i) the force-moment equilibrium equation of biped robots, (ii) frictions applied by each leg on the ground to hold the biped robot without slippage and tipping over, and (iii) physical limits of the motors. Simulations demonstrate that the proposed strategy is effective for energy-efficient biped walking.

PLANNING OF SAGITTAL GAIT OF BIPED ROBOTS BASED ON MINIMUM MOTION ENERGY

2010 ◽  
Vol 07 (04) ◽  
pp. 635-667 ◽  
Author(s):  
KUO-YANG TU ◽  
MI-SHIN LIU
Keyword(s):  
Lower Limb ◽  
Optimal Trajectory ◽  
Biped Robot ◽  
Inverse Kinematic ◽  
Biped Robots ◽  
Motion Energy ◽  
Walking Pattern ◽  
Acceleration And Deceleration ◽  
Zero Moment ◽  
Kinetic And Potential Energies

Traditional planning of biped robot walking patterns solves optimal trajectory for minimizing energy consumption. However, a diversity of biped robot walking functions lead to a variety of walking types. The walking patterns to implement a variety of biped robot objectives should have enough parameters to cope with their functions. In this article, walking patterns based on two 4-3-4 polynomials for the trajectories of biped robot waist and lower limb are proposed. The main advantage of the walking pattern is that 4-3-4 polynomials containing the parameters of acceleration and deceleration for biped walking make the implementation of a variety of walking types possible. In the study, the prototype mechanism of a biped robot is designed. After that, the direct and inverse kinematic equations of the biped robot are derived. For studying motion energy of biped robots, kinetic and potential energies are also defined. Based on these definitions, the parameters of the biped robot trajectories for minimum motion energy are solved. The solution is summarized by a development procedure. In addition, the study of zero moment point (ZMP) during the biped robot in walking is included.

WALKING PATTERN MAPPING FROM IMPERFECT MOTION CAPTURE DATA ONTO BIPED HUMANOID ROBOTS

2010 ◽  
Vol 07 (01) ◽  
pp. 127-156 ◽  
Author(s):  
JUNG-YUP KIM ◽  
YOUNG-SEOG KIM
Keyword(s):  
Motion Capture ◽  
Measurement Errors ◽  
Biped Robot ◽  
Humanoid Robots ◽  
Mapping Method ◽  
Human Motion ◽  
Motion Capture Data ◽  
Biped Robots ◽  
Walking Pattern ◽  
Walking Motion

This paper proposes an efficient walking pattern mapping algorithm from motion capture data onto biped humanoid robots. Currently, the technology known as human motion capture is widely utilized to generate various humanlike motions in many applications, including robotics. An important thing is that several difficulties are associated with motion capture data. These include a data offset issue, noise, and drift problems due to measurement errors caused by imperfect camera calibration, and marker position. If a biped robot uses motion capture data without suitable post-processes, the walking motion of the robot will differ from an actual walking motion, and the Zero Moment Point (ZMP) will be asymmetrical and noisy, leading to unstable walking. A further difficulty exists in the walking pattern mapping process due to the different joint numbers, link sizes, and weights between a human and a robot. Although walking pattern mapping is suitable after addressing the above difficulties, a slip problem between the feet and the ground can continue to cause problems. To solve these difficulties efficiently, a Fourier fitting method is proposed in this research. Improvements of walking pattern and the ZMP trajectory are confirmed using the proposed method. Furthermore, a geometric mapping method is introduced to generate walking patterns for various biped robots while maintaining a degree of similarity to humans. By applying a no-slip constraint to the feet and modifying the joint angles through inverse kinematics, the slip problem is also solved. The effectiveness of the proposed algorithm is verified through computer simulations of two different biped robots that have different sizes, weights, walking cycles, and step lengths.

scholarly journals Contact-Dependent Balance Stability of Biped Robots

2018 ◽  
Vol 10 (2) ◽  
Author(s):  
Carlotta Mummolo ◽  
William Z. Peng ◽  
Carlos Gonzalez ◽  
Joo H. Kim
Keyword(s):  
Stability Boundary ◽  
Theoretical Models ◽  
Biped Robot ◽  
Walking Robots ◽  
Stability Boundaries ◽  
Biped Robots ◽  
Double Support ◽  
Contact Configuration ◽  
Multiple Contacts ◽  
Balance Stability

A theoretical–algorithmic framework for the construction of balance stability boundaries of biped robots with multiple contacts with the environment is proposed and implemented on a robotic platform. Comprehensive and univocal definitions of the states of balance of a generic legged system are introduced with respect to the system's contact configuration. Theoretical models of joint-space and center of mass (COM)-space dynamics under multiple contacts, distribution of contact wrenches, and robotic system parameters are established for their integration into a nonlinear programing (NLP) problem. In the proposed approach, the balance stability capabilities of a biped robot are quantified by a partition of the state space of COM position and velocity. The boundary of such a partition provides a threshold between balanced and falling states of the biped robot with respect to a specified contact configuration. For a COM state to be outside of the stability boundary represents the sufficient condition for falling, from which a change in the system's contact is inevitable. Through the calculated stability boundaries, the effects of different contact configurations (single support (SS) and double support (DS) with different step lengths) on the robot's balance stability capabilities can be quantitatively evaluated. In addition, the balance characteristics of the experimental walking trajectories of the robot at various speeds are analyzed in relation to their respective stability boundaries. The proposed framework provides a contact-dependent balance stability criterion for a given system, which can be used to improve the design and control of walking robots.

Design and Analysis of a Foot Contact Sensor for Posture Control of a Biped Robot

2010 ◽  
Author(s):  
Koray K. S¸afak ◽  
T. Batuhan Baturalp
Keyword(s):  
Postural Stability ◽  
Low Cost ◽  
Reaction Force ◽  
Biped Robot ◽  
Stability Control ◽  
Ease Of Use ◽  
Force Sensors ◽  
Biped Robots ◽  
Contact Sensor ◽  
Computation Scheme

Development of a planar biped robot is currently underway at Yeditepe University. The robot consists of lower extremities with a torso that are designed at anthropomorphic dimensions. This study describes the design and testing of a foot contact sensor for the biped robot. Dynamic stability of a biped robot is commonly measured by the zero moment point (ZMP) method. Experimentally, ZMP is measured by multi-component force/torque sensors. Due to their low cost and ease of use, force sensitive resistors (FSR) are used to build a foot contact sensor for the biped robot. Four FSRs are mounted at the corners of the robot’s foot to measure the ground reaction force and its moment. Hence, by utilizing the data from the foot contact sensors, a real-time ZMP computation scheme can be implemented. The performance of the designed foot contact sensor is presented by numerical simulations of a planar biped robot’s postural stability control. Results indicate that reaction force computation by the FSR based force sensors is a viable method to monitor postural stability of biped robots. Force sensors and their electronics are currently being built to be used for the actual tests.

Modeling, stability and walking pattern generators of biped robots: a review

Robotica ◽  
2013 ◽  
Vol 32 (6) ◽  
pp. 907-934 ◽  
Author(s):  
Hayder F. N. Al-Shuka ◽  
F. Allmendinger ◽  
B. Corves ◽  
Wen-Hong Zhu
Keyword(s):  
Artificial Intelligence ◽  
Control Strategies ◽  
Biped Robot ◽  
Human Locomotion ◽  
Biped Robots ◽  
Walking Pattern ◽  
Control Electronics ◽  
The Subject ◽  
Pattern Generators

SUMMARYBiped robots have gained much attention for decades. A variety of researches have been conducted to make them able to assist or even substitute for humans in performing special tasks. In addition, studying biped robots is important in order to understand human locomotion and to develop and improve control strategies for prosthetic and orthotic limbs. This paper discusses the main challenges encountered in the design of biped robots, such as modeling, stability and their walking patterns. The subject is difficult to deal with because the biped mechanism intervenes with mechanics, control, electronics and artificial intelligence. In this paper, we collect and introduce a systematic discussion of modeling, walking pattern generators and stability for a biped robot.

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.

Walking Pattern Filter for Dynamic Biped Robot With SMA Actuators

Aerospace ◽  
2006 ◽  
Author(s):  
E. Tarkesh Esfahani ◽  
Mohammad Elahinia
Keyword(s):  
Biped Robot ◽  
Human Motion ◽  
Main Criterion ◽  
Biped Robots ◽  
Sma Actuators ◽  
Walking Pattern ◽  
Delay Times ◽  
Zero Moment ◽  
The Stability ◽  
The Given

In this paper we present a walking pattern filter for Shape Memory Alloy (SMA) actuated biped robots. SMAs are known for their slow response. The actuation speed limitation can potentially lead to stability problems for biped robots. This filter adapts the human motion for a SMA biped in order to have a stable walking pattern. The Zero Moment Point (ZMP) is used as a main criterion of the filter to guarantee the stability of the motion. The SMA actuators are designed based on the dynamic and kinematics data of the motion. The response time of each SMA actuator is modeled in order to estimate the behavior of the actuator in realizing the given trajectory. After applying the delay times to the motion new trajectories are generated and checked by the ZMP criterion. The output of the filter can generate smooth trajectories for the SMA biped robots. The filter furthermore guarantees the stability while mimicking the human motion. The filter provides a practical way to create stable walking patterns using SMA actuators.

Stability Region-Based Analysis of Walking and Push Recovery Control

2020 ◽  
Author(s):  
William Z. Peng ◽  
Hyunjong Song ◽  
Joo H. Kim
Keyword(s):  
Biped Robot ◽  
Step Length ◽  
Stability Control ◽  
Human Gait ◽  
Biped Robots ◽  
Reduced Order ◽  
Double Support ◽  
Push Recovery ◽  
The Stability ◽  
Time Required

Abstract Push recovery is a vital aspect of balance stability control in biped robots. In this work, the response of a biped system to unexpected external perturbations is analyzed for different tasks and controllers using stability criteria based on balanced and steppable regions. The steppable region for a given step length and the balanced regions for single and double support contacts are constructed for a biped robot using optimization with its system dynamics, kinematic limits, actuation limits, and contact interactions with the environment. The regions are compared with those of a human subject to demonstrate that human gait exhibits unbalanced (but steppable) phases largely absent in robotic gait. These regions are also applied to a comparative analysis against capturability, where the computed steppable region is significantly larger than the capture region of an equivalent reduced-order model. The stability regions are also used to compare the performance of controllers during a double support balancing task. The implemented hip, knee, and ankle strategy-based controller led to improved stabilization — i.e., decreased foot tipping and time required to balance — relative to an existing hip and ankle controller and a gyro feedback controller. The proposed approaches are applicable to the analysis of any bipedal task and stability controller in general.

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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