A NEW STABILITY CRITERION FOR HUMAN SEATED TASKS WITH GIVEN POSTURES

2012 ◽  
Vol 09 (03) ◽  
pp. 1250015 ◽  
Author(s):  
BRADLEY HOWARD ◽  
JINGZHOU YANG
Keyword(s):  
Stability Analysis ◽  
Stability Criterion ◽  
Center Of Mass ◽  
Reaction Force ◽  
Joint Torque ◽  
Human Model ◽  
Digital Human Model ◽  
Applied Forces ◽  
The Stability ◽  
Digital Human

In digital human modeling (DHM), the analysis of postural stability has five main goals: to determine if a posture is stable or unstable through an explicit criterion; to quantify the level of stability or provide a margin of stability that accounts for the height of the center of mass (COM) above the support plane(s); to be valid in the presence of externally applied forces and moments; be able to assess stability when multiple noncoplanar support planes exist, as is the case with seated postures; and to give insight into the support reaction force (SRF) distribution. To date, there is not a method for analyzing stability that can effectively meet each goal. This paper presents a new stability criterion and stability analysis that accomplishes each intended goal. The stability analysis is derived from the calculation of joint torque using the recursive Lagrangian dynamic formulation. A 56-degree-of-freedom (DOF) articulated digital human model is used to model seated postures to demonstrate the proposed stability criterion. Different given postures with different external load cases are presented.

Effect of Foot Location on Human Running Prediction

2014 ◽  
Author(s):  
Hyun-Joon Chung ◽  
Rajan Bhatt ◽  
Yujiang Xiang ◽  
Jasbir S. Arora ◽  
Karim Abdel-Malek
Keyword(s):  
Degrees Of Freedom ◽  
Reaction Force ◽  
Performance Measure ◽  
Joint Torque ◽  
Upper Body ◽  
Human Model ◽  
Digital Human Model ◽  
Digital Human ◽  
Dynamics Method ◽  
Human Running

Human running is simulated in this work by using a skeletal digital human model with 55 degrees of freedom (DOFs). A predictive dynamics method is used to formulate the running problem, and normal running is formulated as a symmetric and cyclic motion. The dynamic effort and impulse are used as the performance measure, and the upper body yawing moment is also included in the performance measure. The joint angle profiles and joint torque profiles are calculated for the full-body human model, and the ground reaction force is determined. The effect of foot location on the running motion prediction are simulated and studied.

Determining the Static Joint Torques of a Digital Human Model Considering Balance

2009 ◽  
Author(s):  
Jingzhou James Yang ◽  
Yujiang Xiang ◽  
Joo Kim
Keyword(s):  
Human Model ◽  
Joint Torques ◽  
Digital Human Model ◽  
Human Models ◽  
Support Reaction ◽  
Reaction Forces ◽  
Zero Moment ◽  
The Stability ◽  
Physics Based Simulation ◽  
Digital Human

This paper presents a methodology for determining the static joint torques of a digital human model considering balance for both standing and seating tasks. An alternative and efficient formulation of the Zero-Moment Point (ZMP) for static balance and the approximated (ground/seat) support reaction forces/moments are derived from the resultant reaction loads, which includes the gravity and externally applied loads. The proposed method can be used for both standing and seating tasks for assessing the stability/balance of the posture. The proposed formulation can be beneficial to physics-based simulation of humanoids and human models. Also, the calculated joint torques can be considered as an indicator to assess the risks of injuries when human models perform various tasks.

Industrial Design of Motorcycle with Reference to Indian Population

2014 ◽  
Vol 592-594 ◽  
pp. 2659-2664 ◽  
Author(s):  
T. Jeyakumar ◽  
R. Gandhinathan
Keyword(s):  
Optimal Solution ◽  
Human Model ◽  
Anthropometric Data ◽  
Posture Analysis ◽  
Digital Human Model ◽  
Set Up ◽  
The Aesthetic ◽  
Decision Making Model ◽  
Digital Human ◽  
Data Collection Approach

India is the second largest 2W market in the world in terms of sales volumes after China. Motorcycles types that are marketed using sports tag are found to be anchored on performance attributes characterized by visual appeal, higher speeds, heady acceleration and superior ride, handling and braking. The chronograph of the sports segment in the Indian market is plotted. A goal defined design process is developed to produce creative ideas for aesthetic attributes-modern, youthful, aerodynamic, and aggressive. The optimal solution satisfying the aesthetic goal is determined using an operation decision making model based upon weighted generalized mean method. A motorcycle is generally straddled by the rider with manual transmission and can be considered as a constrained workstation. Some ergonomic considerations to fit users of different sizes on the same workstation should be taken into account when designing. A two-dimensional anthropometric data collection approach is followed for riders in India. The obtained anthropometric data concerning riding postures are used for posture analysis using digital human model in CAD software. The mutual trade-off between sporty riding style of the rider and comfort angles have been arrived to set up the final posture of the rider. The detailing of the appearance considering the aesthetic attributes and ergonomics are done. The developed design is aimed at improving appearance and ergonomic performance.

Human Carrying Simulation With Symmetric and Asymmetric Loads

2012 ◽  
Author(s):  
Yujiang Xiang ◽  
Jasbir S. Arora ◽  
Salam Rahmatalla ◽  
Hyun-Joon Chung ◽  
Rajan Bhatt ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Human Motion ◽  
Human Model ◽  
Physical Constraints ◽  
Digital Human Model ◽  
Load Carrying ◽  
Reaction Forces ◽  
Asymmetric Load ◽  
Optimization Schemes ◽  
Digital Human

Human carrying is simulated in this work by using a skeletal digital human model with 55 degrees of freedom (DOFs). Predictive dynamics approach is used to predict the carrying motion with symmetric and asymmetric loads. In this process, the model predicts joints dynamics using optimization schemes and task-based physical constraints. The results indicated that the model can realistically match human motion and ground reaction forces data during symmetric and asymmetric load carrying task. With such prediction capability the model could be used for biomedical and ergonomic studies.

Walking Stability Analysis of Multi-Legged Crablike Robot over Slope

2013 ◽  
Vol 572 ◽  
pp. 636-639
Author(s):  
Xi Chen ◽  
Gang Wang
Keyword(s):  
Mathematical Model ◽  
Stability Analysis ◽  
Stability Criterion ◽  
Stability Margin ◽  
Static Stability ◽  
Matlab Simulation ◽  
And Performance ◽  
The Stability ◽  
The Mathematical Model ◽  
The Relationship

This paper deals with the walking stability analysis of a multi-legged crablike robot over slope using normalized energy stability margin (NESM) method in order to develop a common stabilization description method and achieve robust locomotion for the robot over rough terrains. The robot is simplified with its static stability being described by NESM. The mathematical model of static stability margin is built so as to carry out the simulation of walking stability over slope for the crablike robot that walks in double tetrapod gait. As a consequence, the relationship between stability margin and the height of the robots centroid, as well as its inclination relative to the ground is calculated by the stability criterion. The success and performance of the stability criterion proposed is verified through MATLAB simulation and real-world experiments using multi-legged crablike robot.

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