B-24 Formulation of a forward dynamics analysis of human movement with consideration of constraint axes of joints

2009 ◽  
Vol 2009 (0) ◽  
pp. 349-354
Author(s):  
Sekiya KOIKE ◽  
Tatsuya ISHIKAWA
Keyword(s):  
Human Movement ◽  
Dynamics Analysis ◽  
Forward Dynamics

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.

The Importance of Biarticular Torque Generators in Torque-Driven Simulation Models

2012 ◽  
Author(s):  
Mark King ◽  
Martin Lewis
Keyword(s):  
Simulation Models ◽  
Human Movement ◽  
Forward Dynamics ◽  
Strength Parameters ◽  
Individual Muscle ◽  
Torque Measurements ◽  
Biarticular Muscles ◽  
Subject Specific ◽  
Computer Simulation Models ◽  
Muscle Models

Forward-dynamics computer simulation models of human movement are typically driven by individual muscle models, or torque generators. In muscle-driven models, muscle parameters are typically determined from experimental data in the literature. While in torque-driven models, subject-specific torque parameters can be determined from torque measurements collected on an isovelocity dynamometer. Such a method avoids some of the errors encountered with individual muscle models by determining strength parameters directly from torque measurements. The disadvantage of existing subject-specific torque generator models over individual muscle models has been that the torque exerted at a joint has been represented by a function of the kinematics of the primary joint. As such torque generator models may not accurately represent the torques exerted by biarticular muscles where the kinematics of a primary and secondary joint may be important.

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.

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