3D simulation of manual material handling tasks based on nonlinear optimization method



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Texas Tech University


Two biomechanical approaches were launched in this study to simulate and investigate the manual material handling (MMH) activities. The first is a biomechanical simulation approach. In this approach, an inverse kinematics computation with nonlinear optimization method was applied to simulate MMH. Mathematically, the approach was expressed as a system of nonlinear equations with an objective function and a set of constraints, which was solved using an iterative numerical algorithm. The second is a dynamic & control approach. In this approach, the human body was viewed as a two-link rigid body (upper body and lower body) control system, which can control the muscles to generate different joint torques (ankle torque and hip torque) to compensate the external load moment which was be considered as a perturbation at different phase and posture during lifting. The body postural responses to a wide range of perturbations were simulated.

To test and validate these two modeling approaches, a factorial experiment was conducted to obtain the kinematics data for different task conditions. A set of kinematics (angular displacement and angular velocity) and kinetic parameters (joint torque and compressive forces) was analyzed. The experiment results showed that the simulated data fit well with the experiment data and further insights of the human control strategy of MMH were gained by statistical analysis.



Three-dimenstional (3-D) simulation, Nonlinear optimization method