scholarly journals Anti-Slip Gait Planning for a Humanoid Robot in Fast Walking

2019 ◽  
Vol 9 (13) ◽  
pp. 2657 ◽  
Author(s):  
Fangzhou Zhao ◽  
Junyao Gao
Keyword(s):  
Walking Speed ◽  
Control Method ◽  
Humanoid Robots ◽  
Mass Model ◽  
Gait Planning ◽  
Fast Walking ◽  
Zero Moment ◽  
Constraint Method ◽  
Rotational Slip

Humanoid robots are expected to have broad applications due to their biped mobility and human-like shape. To increase the walking speed, it is necessary to increase the power for driving the joints of legs. However, the resulting mass increasing of the legs leads to a rotational slip when a robot is walking fast. In this paper, a 3D three-mass model is proposed, in which both the trunk and thighs are regarded as an inverted pendulum, and the shanks and feet are considered as mass-points under no constraints with the trunk. Then based on the model, a friction constraint method is proposed to plan the trajectory of the swing leg in order to achieve the fastest walking speed without any rotational slip. Furthermore, the compensation for zero-moment point (ZMP) is calculated based on the 3D three-mass model, and the hip trajectory is obtained based on the compensated ZMP trajectory by using the preview control method, thus improving the robot’s overall ZMP follow-up effect. This planning method involves simple calculations but reliable results. Finally, simulations confirm that the rotational slip is avoided while stable and fast walking is realized, with free joints of the waist and arms, which then could be planned for other tasks.

Dynamic Cooperative Manipulating Pattern Generation for Mobile Humanoid Robot Using Waist Moment Compensation

2011 ◽  
Vol 201-203 ◽  
pp. 1978-1982
Author(s):  
Tie Jun Zhao
Keyword(s):  
Humanoid Robot ◽  
Control Method ◽  
Dynamic Effect ◽  
Humanoid Robots ◽  
Pattern Generation ◽  
Whole Body ◽  
Robotic Arm ◽  
Living Space ◽  
Zero Moment ◽  
The Stability

This research is aimed at dynamically stable motion and safety of mobile humanoid robots expected to work in a human living space. The mechanism of the mobile humanoid robot YIREN is described. A highly flexible anthropomorphic 7-DOF robotic arm and a new waist configuration with parallel driving motor are developed. Because the dynamitic behavior of manipulator and waist has an effect on the stability of mobile humanoid robots, the dynamitic model is built. By using the zero moment point, dynamic effect of the waist is obtained. A basic control method of whole body cooperative dynamic moving is proposed that uses waist cooperative motion to compensate for moment generated by the trajectory of the arms and the correctness of analysis is verified by experiments.

AN ANALYTICAL METHOD FOR REAL-TIME GAIT PLANNING FOR HUMANOID ROBOTS

2006 ◽  
Vol 03 (01) ◽  
pp. 1-19 ◽  
Author(s):  
KENSUKE HARADA ◽  
SHUUJI KAJITA ◽  
KENJI KANEKO ◽  
HIROHISA HIRUKAWA
Keyword(s):  
Real Time ◽  
Analytical Method ◽  
Humanoid Robot ◽  
Humanoid Robots ◽  
Center Of Gravity ◽  
Gait Planning ◽  
The Real ◽  
Smooth Change ◽  
Simulation And Experiment ◽  
Zero Moment

This paper studies real-time gait planning for a humanoid robot. By simultaneously planning the trajectories of the COG (Center of Gravity) and the ZMP (Zero Moment Point), a fast and smooth change of gait can be realized. The change of gait is also realized by connecting the newly calculated trajectories to the current ones. While we propose two methods for connecting two trajectories, i.e. the real-time method and the quasi-real-time one, we show that a stable change of gait can be realized by using the quasi-real-time method even if the change of the step position is significant. The effectiveness of the proposed methods are confirmed by simulation and experiment.

Walking capacities in multiple sclerosis measured by global positioning system odometer

2007 ◽  
Vol 13 (2) ◽  
pp. 220-223 ◽  
Author(s):  
A Créange ◽  
I Serre ◽  
M Levasseur ◽  
D Audry ◽  
A Nineb ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Global Positioning System ◽  
Walking Speed ◽  
Walking Distance ◽  
Expanded Disability Status Scale ◽  
Satellite Technology ◽  
Promising Tool ◽  
Disability Status ◽  
Global Positioning

We used a global positioning satellite technology odometer to determine the maximum objective walking distance capacity (MOWD) of patients with multiple sclerosis (MS). The MOWD correlated with Expanded Disability Status Scale (EDSS) score (r2 =0.41; P < 0.0001), the MSWS-12 scale (r2 = 0.46; P < 0.0001), time to walk 10 m (r2 = 0.51; P < 0.02) and walking speed (r2 =0.75; P < 0.001). Limitation of walking capacities was measurable up to 4550 m, strikingly above the 500-m limit of the EDSS. This objective odometer is a promising tool for evaluation and follow-up of patients with MS. Multiple Sclerosis 2007; 13: 220–223. http://msj.sagepub.com

ZMP: A REVIEW OF SOME BASIC MISUNDERSTANDINGS

2006 ◽  
Vol 03 (02) ◽  
pp. 153-175 ◽  
Author(s):  
MIOMIR VUKOBRATOVIĆ ◽  
BRANISLAV BOROVAC ◽  
VELJKO POTKONJAK
Keyword(s):  
Degrees Of Freedom ◽  
Dynamic Balance ◽  
Decisive Role ◽  
Humanoid Robots ◽  
Ground Contact ◽  
Science And Engineering ◽  
Theoretical Assumptions ◽  
Zero Moment ◽  
Basic Characteristics

One of basic characteristics of the regular bipedal walk of humanoid robots is the maintenance of their dynamic balance during the walk, whereby a decisive role is played by the unpowered degrees of freedom arising at the foot–ground contact. Hence, the role of the Zero-Moment Point (ZMP) as an indicator of dynamic balance is indispensable. This paper gives a detailed discussion of some basic theoretical assumptions related to the ZMP in the light of imprecise, and even incorrect, interpretations that have recently appeared, and which have led to some erroneous conclusions. Examples are given to show some erroneous basic attitudes and the genesis of some of them is indicated. It is also pointed out that in the domain of bipedal walk there are still notions that are not clearly defined and their meanings differentiated in some related branches of science and engineering. One of the examples is dynamic balance and stability, which are often used interchangeably.

scholarly journals Endoscopic removal of an incidentally discovered intrauterine contraceptive device eroding into the rectum

2019 ◽  
Vol 12 (9) ◽  
pp. e231410
Author(s):  
Mahdi Abdulrasoul Al Sahaf ◽  
Bahaa Farouk Bseiso ◽  
Sami Abdulmohsin Al-Momen ◽  
Abdul-Wahed Nasir Meshikhes
Keyword(s):  
Control Method ◽  
Intrauterine Contraceptive Device ◽  
Contraceptive Device ◽  
Birth Control Method ◽  
Endoscopic Removal ◽  
Rectosigmoid Colon ◽  
Diagnostic Colonoscopy ◽  
Intrauterine Contraceptive ◽  
Pelvic Viscera

Intrauterine contraceptive device (IUCD) is a common birth control method. It is safe but can be associated with serious complications including migration into the peritoneal cavity and penetration into other intra-abdominal and pelvic viscera; most commonly the rectosigmoid colon. Different retrieval methods including endoscopy, laparoscopy or open abdominal surgery have been described. We report the case of 38-year-old woman who became pregnant shortly after insertion of the IUCD 6 years prior to presentation. She delivered vaginally and ‘expulsion’ of the device was assumed. Some 4 years later, she had another IUCD inserted and remained asymptomatic till she recently presented with iron-deficiency anaemia. As part of the investigation, diagnostic colonoscopy was performed. Surprisingly, the old IUCD was found penetrating into the midrectum. Uneventful endoscopic removal was performed and she remained well at 3-month follow-up. Migrating IUCD remains asymptomatic and may be discovered accidentally during routine investigation for some other symptoms.

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