scholarly journals Reuleaux Triangle—Based Two Degrees of Freedom Bipedal Robot

Robotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 114
Author(s):  
Jiteng Yang ◽  
Wael Saab ◽  
Yujiong Liu ◽  
Pinhas Ben-Tzvi
Keyword(s):  
Degrees Of Freedom ◽  
Body Height ◽  
Step Length ◽  
Bipedal Robot ◽  
Dynamic Simulations ◽  
Reuleaux Triangle ◽  
Modeling Analysis ◽  
Cam Follower ◽  
Walking Velocity ◽  
Forward Locomotion

This paper presents the design, modeling, analysis, and experimental results of a novel bipedal robotic system that utilizes two interconnected single degree-of-freedom (DOF) leg mechanisms to produce stable forward locomotion and steering. The single DOF leg is actuated via a Reuleaux triangle cam-follower mechanism to produce a constant body height foot trajectory. Kinematic analysis and dimension selection of the Reuleaux triangle mechanism is conducted first to generate the desired step height and step length. Leg sequencing is then designed to allow the robot to maintain a constant body height and forward walking velocity. Dynamic simulations and experiments are conducted to evaluate the walking and steering performance. The results show that the robot is able to control its body orientation, maintain a constant body height, and achieve quasi-static locomotion stability.

scholarly journals Regulation of Step Length and Walking Velocity on Gait in Mounting a Treadmill

2007 ◽  
Vol 22 (1) ◽  
pp. 163-166
Author(s):  
Takayuki SHIMOJU ◽  
Hiroaki TANI
Keyword(s):  
Step Length ◽  
Walking Velocity

scholarly journals Center of Pressure Feedback for Controlling the Walking Stability Bipedal Robots using Fuzzy Logic Controller

2018 ◽  
Vol 8 (5) ◽  
pp. 3678
Author(s):  
Afrizal Mayub ◽  
Fahmizal Fahmizal
Keyword(s):  
Fuzzy Logic ◽  
Degrees Of Freedom ◽  
Fuzzy Logic Controller ◽  
Center Of Pressure ◽  
Bipedal Robots ◽  
Bipedal Robot ◽  
Position Information ◽  
Pressure Feedback ◽  
The Stability ◽  
Foot Pad

This paper presents a sensor-based stability walk for bipedal robots by using force sensitive resistor (FSR) sensor. To perform walk stability on uneven terrain conditions, FSR sensor is used as feedbacks to evaluate the stability of bipedal robot instead of the center of pressure (CoP). In this work, CoP that was generated from four FSR sensors placed on each foot-pad is used to evaluate the walking stability. The robot CoP position provided an indication of walk stability. The CoP position information was further evaluated with a fuzzy logic controller (FLC) to generate appropriate offset angles to be applied to meet a stable situation. Moreover, in this paper designed a FLC through CoP region's stability and stable compliance control are introduced. Finally, the performances of the proposed methods were verified with 18-degrees of freedom (DOF) kid-size bipedal robot.<br /><br />

scholarly journals Jumping in frogs: assessing the design of the skeletal system by anatomically realistic modeling and forward dynamic simulation

2002 ◽  
Vol 205 (12) ◽  
pp. 1683-1702 ◽  
Author(s):  
William J. Kargo ◽  
Frank Nelson ◽  
Lawrence C. Rome
Keyword(s):  
Degrees Of Freedom ◽  
The Body ◽  
Joint Torque ◽  
Rotational Degree ◽  
Skeletal System ◽  
Dynamic Simulations ◽  
Inverse Dynamic ◽  
Maximal Distance ◽  
Out Of Plane ◽  
Rotational Degrees Of Freedom

SUMMARY Comparative musculoskeletal modeling represents a tool to understand better how motor system parameters are fine-tuned for specific behaviors. Frog jumping is a behavior in which the physical properties of the body and musculotendon actuators may have evolved specifically to extend the limits of performance. Little is known about how the joints of the frog contribute to and limit jumping performance. To address these issues, we developed a skeletal model of the frog Rana pipiens that contained realistic bones, joints and body-segment properties. We performed forward dynamic simulations of jumping to determine the minimal number of joint degrees of freedom required to produce maximal-distance jumps and to produce jumps of varied take-off angles. The forward dynamics of the models was driven with joint torque patterns determined from inverse dynamic analysis of jumping in experimental frogs. When the joints were constrained to rotate in the extension—flexion plane, the simulations produced short jumps with a fixed angle of take-off. We found that, to produce maximal-distance jumping,the skeletal system of the frog must minimally include a gimbal joint at the hip (three rotational degrees of freedom), a universal Hooke's joint at the knee (two rotational degrees of freedom) and pin joints at the ankle,tarsometatarsal, metatarsophalangeal and iliosacral joints (one rotational degree of freedom). One of the knee degrees of freedom represented a unique kinematic mechanism (internal rotation about the long axis of the tibiofibula)and played a crucial role in bringing the feet under the body so that maximal jump distances could be attained. Finally, the out-of-plane degrees of freedom were found to be essential to enable the frog to alter the angle of take-off and thereby permit flexible neuromotor control. The results of this study form a foundation upon which additional model subsystems (e.g. musculotendon and neural) can be added to test the integrative action of the neuromusculoskeletal system during frog jumping.

scholarly journals Bondgraph modelling and simulation of the dynamic behaviour of above-knee prostheses

1987 ◽  
Vol 11 (2) ◽  
pp. 65-70 ◽  
Author(s):  
P. G. Van De Veen ◽  
W. Van Der Tempel ◽  
J. De Vreiss
Keyword(s):  
Mathematical Model ◽  
Computer Simulation ◽  
Mass Distribution ◽  
Total Mass ◽  
Dynamic Behaviour ◽  
Step Length ◽  
Swing Phase ◽  
Knee Prostheses ◽  
Prosthetic Foot ◽  
Walking Velocity

A mathematical model was used to investigate the dynamic behaviour of an above-knee (AK) prosthesis in the swing phase and to analyse the influence of mass and mass distribution on the maximal stump load and the required energy. The model consists of a bondgraph model of the prosthesis and a “walking” model which predicts the walking velocity, step length and the femoral trajectory. Equipment was developed to measure the inertial properties of the components of the prosthesis. Through computer simulation, stickdiagrams of the swing phase and graphs of the variation with time of the hip and stump forces were obtained. It was found that for a normal AK prosthesis with a knee-lock mechanism the axial stump load is greatest at the beginning and at the end of the swing phase. At a walking velocity of 5 km/hr the maximum axial stump load amounts to 2.1 times the static weight of the prosthesis. The maximum axial stump force appeared to be almost directly proportional to the total mass of the prosthesis but independent of the mass distribution. The required energy also increased with the mass of the prosthesis but is' dependent on mass distribution. Because of their comparable weights the influence of the shoe is almost equal to the influence of the prosthetic foot. Thus lightweight shoes should be used with lightweight prosthetic feet in order to add to their advantages.

scholarly journals Gait Training Methods and ChangesiIn Gait Parameters in Parkinson`s Disease (Literature Review)

2020 ◽  
Vol 2 (7) ◽  
Author(s):  
Aušra Stuopelytė ◽  
Rasa Šakalienė
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Step Length ◽  
Gait Training ◽  
Auditory Stimulation ◽  
Training Methods ◽  
Dual Tasking ◽  
Gait Parameters ◽  
Rhythmic Auditory Stimulation ◽  
Walking Velocity

Parkinson’s disease is a chronic progressive neurological disorder that can impact function to a variable degree. Changes in gait parameters are the most common signs of Parkinson’s disease. Patients with Parkinson’s disease walk with a reduced step length, step time, walking velocity and walking cadence, increased stride cycle time, coefficient of variation of the step amplitude and step time and increased risk to fall. So, various gait training methods are applied. The effect of rhythmic auditory stimulation on gait in Parkinson’s disease patients is analysed. We can use various kinds of music, metronome, scansion and clapping as a rhythmic auditory stimulation.One of gait training methods in Parkinson’s disease patients is treadmill training. There are attempts to combine treadmill training with transcranial magnetic stimulation and virtual reality. We can use Nordic walking method and because walking technique requires straight posture, trunk rotation, bigger step and heel stride. More often robot–assisted gait training is used in patients with Parkinson’s disease gait training. The effect of dual–tasking and walking with music methods for gait and balance training in patients with Parkinson’s disease is also analysed. This method requires participants to perform primary and secondary tasks at the same time. The secondary task can be cognitive or motor. Dual–tasking is widely analysed because opinions about applying this method are very controversial. Walking with music method is more often analysed in scientific literature. This method could not be compared to rhythmic auditory stimulation method because the latter requires precise walking to rhythm and walking with music method is oriented to emotional component (music is chosen according patients’ music taste). As these methods are applied, we can see an increase in chosen walking and maximal walking velocities, step length and time, distance covered, and decrease in the coefficient of variation of the step time and turning time.Keywords: Gait impairments, walking velocity, rhythmic auditory stimulation.

The Effect of a Fractal Profile Tolerance on the Dynamic Performance of Cams

1996 ◽  
Author(s):  
Daniel A. McAdams ◽  
Kristin L. Wood
Keyword(s):  
Fractal Geometry ◽  
Surface Characterization ◽  
Dynamic Performance ◽  
Design Parameters ◽  
Fractal Surface ◽  
Profile Error ◽  
Dynamic Simulations ◽  
Profile Tolerance ◽  
Cam Follower ◽  
Successful Design

Abstract To ensure a successful design, it is important to understand the effect that design parameters have on design performance. Tolerances are an important subset of design parameters. In this paper, the relevance of fractal surface characterization for profile tolerances is investigated. The notion of fractal geometry is discussed. The validity of a fractal characterization on a cam surface is determined. Dynamic simulations of a cam-follower system are used to qualify the effect of a fractal profile error on system performance.

The mechanics of locating earthquakes

1976 ◽  
Vol 66 (1) ◽  
pp. 173-187
Author(s):  
Ray Buland
Keyword(s):  
Degrees Of Freedom ◽  
A Priori Estimates ◽  
A Priori ◽  
Joint Probability ◽  
Step Length ◽  
Earth Model ◽  
Random Errors ◽  
Qr Algorithm ◽  
Location Parameters ◽  
Chi Squared

abstract A complete reexamination of Geiger's method in the light of modern numerical analysis indicates that numerical stability can be insured by use of the QR algorithm and the convergence domain considerably enlarged by the introduction of step-length damping. In order to make the maximum use of all data, the method is developed assuming a priori estimates of the statistics of the random errors at each station. Numerical experiments indicate that the bulk of the joint probability density of the location parameters is in the linear region allowing simple estimates of the standard errors of the parameters. The location parameters are found to be distributed as one minus chi squared with m degrees of freedom, where m is the number of parameters, allowing the simple construction of confidence levels. The use of the chi-squared test with n-m degrees of freedom, where n is the number of data, is introduced as a means of qualitatively evaluating the correctness of the earth model.

Proximal-to-Distal Sequencing and Coordination Variability in the Volleyball Spike of Elite Youth Players: Effects of Gender and Growth

2018 ◽  
Vol 6 (2) ◽  
pp. 250-266 ◽  
Author(s):  
Ben Serrien ◽  
Maggy Goossens ◽  
Jean-Pierre Baeyens
Keyword(s):  
Degrees Of Freedom ◽  
Body Height ◽  
Development Program ◽  
Wrist Flexion ◽  
Trunk Flexion ◽  
Self Organizing Maps ◽  
And Performance ◽  
Coordination Patterns ◽  
Motion Capturing ◽  
Motor Control Systems

The aim of this article was to examine changes in elite youth volleyball players’ performance, proximal-to-distal sequencing, and coordination variability of the spike motion between the start and after 1 year of a talent development program. Eight boys and eight girls in late puberty/early adolescence were measured with 3D motion capturing for 2 consecutive years. Performance and performance variability increased and decreased, respectively, but both changes were not significantly correlated with growth. Gender differences were identified for proximal-to-distal sequencing, but a very strong similarity between both years was observed for all seven degrees of freedom (pelvis and trunk rotation, trunk flexion, shoulder horizontal adduction, shoulder internal rotation, elbow extension, and wrist flexion). The fact that this sequence was kept stable, despite marked growth effects, likely indicates that this sequence is biomechanically efficient and the motor control systems try to preserve it. Coordination variability was analyzed by coordination profiling with self-organizing maps. The decrease in coordination variability correlated strongly and significantly with increase in body height. Participants with stronger growth rates were observed to show smaller decreases in coordination variability, which possibly represents a mechanism to explore various coordination patterns to adapt to the more rapidly changing organismic constraints.

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