B-25 A converting algorithm of the motion dependent term into the joint torque term in forward dynamics analysis of human movement

2009 ◽  
Vol 2009 (0) ◽  
pp. 355-360
Author(s):  
Sekiya KOIKE ◽  
Tatsuya ISHIKAWA
Keyword(s):  
Human Movement ◽  
Joint Torque ◽  
Dynamics Analysis ◽  
Forward Dynamics ◽  
Dependent Term

An EMG-Driven Forward Dynamics Model to Simulate Stance Phase of Gait

2009 ◽  
Author(s):  
Qi Shao ◽  
Kurt Manal ◽  
Thomas S. Buchanan
Keyword(s):  
Muscle Activation ◽  
Stance Phase ◽  
Control Strategies ◽  
Neuromuscular Control ◽  
Human Movement ◽  
Joint Torque ◽  
Forward Dynamics ◽  
Activation Patterns ◽  
Joint Torques ◽  
Muscle Activation Patterns

Simulations based on forward dynamics have been used to identify the biomechanical mechanisms how human movement is generated. They used either net joint torques [1] or muscle forces [2, 3, 4] as actuators to drive forward simulation. However, very few models used EMG-based patterns to define muscle excitations [4] or were actually driven by EMGs. Muscle activation patterns vary from subject to subject and from movement to movement, and the activations depend on the control task, sometimes quite different even for the same joint angle and joint torque [5]. Using EMG as input can account for subjects’ different muscle activation patterns and help revealing the neuromuscular control strategies.

Feedback control of the neuromusculoskeletal system in a forward dynamics simulation of stair locomotion

2009 ◽  
Vol 223 (6) ◽  
pp. 663-675 ◽  
Author(s):  
A Selk Ghafari ◽  
A Meghdari ◽  
G Vossoughi
Keyword(s):  
Feedback Control ◽  
Degrees Of Freedom ◽  
Inverse Dynamics ◽  
Sagittal Plane ◽  
Human Movement ◽  
Stair Climbing ◽  
Dynamics Simulation ◽  
Forward Dynamics ◽  
Control Loops ◽  
The Stability

The aim of this study is to employ feedback control loops to provide a stable forward dynamics simulation of human movement under repeated position constraint conditions in the environment, particularly during stair climbing. A ten-degrees-of-freedom skeletal model containing 18 Hill-type musculotendon actuators per leg was employed to simulate the model in the sagittal plane. The postural tracking and obstacle avoidance were provided by the proportional—integral—derivative controller according to the modulation of the time rate change of the joint kinematics. The stability of the model was maintained by controlling the velocity of the body's centre of mass according to the desired centre of pressure during locomotion. The parameters of the proposed controller were determined by employing the iterative feedback tuning approach to minimize tracking errors during forward dynamics simulation. Simultaneously, an inverse-dynamics-based optimization was employed to compute a set of desired musculotendon forces in the closed-loop simulation to resolve muscle redundancy. Quantitative comparisons of the simulation results with the experimental measurements and the reference muscles' activities illustrate the accuracy and efficiency of the proposed method during the stable ascending simulation.

Dynamic Modeling of Overconstrained Parallel Robot

2013 ◽  
Vol 373-375 ◽  
pp. 34-37
Author(s):  
Jian Xin Yang ◽  
Zhen Tao Liu ◽  
Jian Wei Sun
Keyword(s):  
Dynamic Modeling ◽  
Virtual Work ◽  
Parallel Robot ◽  
Tree Structure ◽  
Kinematics And Dynamics ◽  
Dynamics Analysis ◽  
Forward Dynamics ◽  
Principle Of Virtual Work ◽  
Closed Form Solutions ◽  
Dynamics Models

The dynamic modeling method for parallel robot based on the principle of virtual work and equivalent tree structure is proposed by taking off the platform and the chains as well as degenerating parallel robot into a tree structure, the closed-form solutions for the inverse and forward dynamics models of parallel robot are derived. The method is applied on kinematics and dynamics analysis of a representative 3-RRR spherical parallel robot.

Analysis of Lower Limbs Dynamics and its Application in the Sports Training Based on Computer Vision

2014 ◽  
Vol 513-517 ◽  
pp. 3212-3215
Author(s):  
Sheng Gang Jing ◽  
Wen Yuan Wan
Keyword(s):  
Computer Vision ◽  
Model Building ◽  
Lower Limbs ◽  
Joint Torque ◽  
Visual Simulation ◽  
Dynamics Analysis ◽  
Sports Training ◽  
Analysis Model ◽  
Vision Simulation ◽  
Torque Values

The lower limbs dynamics analysis model was researched, and applied it in the ports training based on computer vision. Through theoretical analysis and computer visual simulation, the detailed theoretical and simulation data was obtained for the lower limbs torque value, which was applied to sports training. Using the computer simulation technology, the human lower limbs skeletal dynamics model was established on the computer visual simulation platform. The joint torque values in different sports models were calculated for analyzing the optimum force and power mode. In the model building process, the single leg support motion model and running model were constructed, and the lower limbs dynamics analysis was implemented for the two models, calculating the joint torque values in theory and simulation. Finally, the ADAMS software was used for dynamic visual simulation in computer vision. Simulation results can show the force torque values vividly, the simulation result and theoretical result are compared and analyzed, it provides important data references and effective theoretical guidance in sports training, and it is meaningful for the optimization of physical training and improvement of training effect.

scholarly journals Are Torque-Driven Simulation Models of Human Movement Limited by an Assumption of Monoarticularity?

2021 ◽  
Vol 11 (9) ◽  
pp. 3852
Author(s):  
Martin G. C. Lewis ◽  
Maurice R. Yeadon ◽  
Mark A. King
Keyword(s):  
Lower Limb ◽  
Simulation Models ◽  
Human Movement ◽  
Joint Torque ◽  
Whole Body ◽  
Countermovement Jump ◽  
Joint Torques ◽  
Large Joint ◽  
Subject Specific ◽  
Similar Accuracy

Subject-specific torque-driven computer simulation models employing single-joint torque generators have successfully simulated various sports movements with a key assumption that the maximal torque exerted at a joint is a function of the kinematics of that joint alone. This study investigates the effect on model accuracy of single-joint or two-joint torque generator representations within whole-body simulations of squat jumping and countermovement jumping. Two eight-segment forward dynamics subject-specific rigid body models with torque generators at five joints are constructed—the first model includes lower limb torques, calculated solely from single-joint torque generators, and the second model includes two-joint torque generators. Both models are used to produce matched simulations to a squat jump and a countermovement jump by varying activation timings to the torque generators in each model. The two-joint torque generator model of squat and countermovement jumps matched measured jump performances more closely (6% and 10% different, respectively) than the single-joint simulation model (10% and 24% different, respectively). Our results show that the two-joint model performed better for squat jumping and the upward phase of the countermovement jump by more closely matching faster joint velocities and achieving comparable amounts of lower limb joint extension. The submaximal descent phase of the countermovement jump was matched with similar accuracy by the two models (9% difference). In conclusion, a two-joint torque generator representation is likely to be more appropriate for simulating dynamic tasks requiring large joint torques and near-maximal joint velocities.

Psychophysical Cost Function of Joint Movement for Arm Reach Posture Prediction

1994 ◽  
Vol 38 (10) ◽  
pp. 636-640 ◽  
Author(s):  
Eui S. Jung ◽  
Jaeho Choe ◽  
Sung H. Kim
Keyword(s):  
Prediction Model ◽  
Cost Function ◽  
Degrees Of Freedom ◽  
Human Movement ◽  
Difficult Problem ◽  
Joint Torque ◽  
Joint Movement ◽  
Human Arm ◽  
Posture Prediction ◽  
Joint Range

A man model can be used as an effective tool to design ergonomically sound products and workplaces, and subsequently evaluate them properly. For a man model to be truly useful, it must be integrated with a posture prediction model which should be capable of representing the human arm reach posture in the context of equipments and workspaces. Since the human movement possesses redundant degrees of freedom, accurate representation or prediction of human movement was known to be a difficult problem. To solve this redundancy problem, a psychophysical cost function was suggested in this study which defines a cost value for each joint movement angle. The psychophysical cost function developed integrates the psychophysical discomfort of joints and the joint range availability concept which has been used for redundant arm manipulation in robotics to predict the arm reach posture. To properly predict an arm reach posture, an arm reach posture prediction model was then developed in which a posture configuration that provides the minimum total cost is chosen. The predictivity of the psychophysical cost function was compared with that of the biomechanical cost function which is based on the minimization of joint torque. Here, the human body is regarded as a two-dimensional multi-link system which consists of four links; trunk, upper arm, lower arm and hand. Real reach postures were photographed from the subjects and were compared to the postures predicted by the model. Results showed that the postures predicted by the psychophysical cost function closely simulated human reach postures and the predictivity was more accurate than that by the biomechanical cost function.

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