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Our previous formulation for optimization-based dynamic motion simulation of a serial-link human upper body (from waist to right hand) is extended to predict the motion of a tree-structured human model that includes the torso, right arm, and left arm, with various applied external loads. The dynamics of tree-structured systems is formulated and implemented. The equations of motion for the tree structures must be derived carefully when dealing with the connection link. The optimum solution results show realistic dual-arm human motions and the required joint actuator torques. In the second part of this paper, a new method is introduced in which the constraint forces and moments at the joints are calculated along with the motion and muscle-induced actuator torques. A set of fictitious joints are modeled in addition to the real joints.

The evaluation of maintenance tasks is increasingly important in the design and redesign of many industrial operations including vehicles. The weight of subsystems can be extreme and often tools are developed to abate the ergonomic risks commonly associated with such tasks, while others are unfortunately overlooked. We evaluated a member of the family of medium-sized tactical vehicles (FMTV) and chose the battery handling from a list of previously addressed concerns regarding the vehicle. Particularly in larger vehicles, similar to those analyzed in this paper, batteries may exceed 35 kg (77 lbs). The motions required to remove these batteries were simulated using motion prediction modules from the Human Motion Simulation (HUMOSIM) laboratory at the University of Michigan. These motions were visualized in UGS PLM Solutions' Jack™ and analyzed with the embedded 3-D Static Strength Prediction program.

Vehicle operators are required to perform a variety of reaching tasks while the vehicle is in motion. The vibration transmitted from the terrain-vehicle coupling can prevent the operator from successfully completing the required task. The level to which vibration inhibits the completion of these tasks must be more clearly understood in order to effectively design controls and displays that minimize these performance decrements. The Ride Motion Simulator (RMS) at the U.S. Army Tank-Automotive Research, Development, and Engineering Center (TARDEC) simulated single-axis and 6DOF ride motion, in which twelve participants were asked to perform push-button reaching tasks to eight RMS-mounted targets. In order to better ascertain the effects of dynamic ride motion on in-vehicle reaching tasks, we used a twelve-camera VICON optical motion capture system to record and UGS PLM Solutions’ Jack™ to analyze the associated kinematic and kinetic motions.

Vehicle motions can adversely affect the ability of a driver or occupant to quickly and accurately push control buttons located in many advanced vehicle control, navigation and communications systems. A pilot study was conducted using the U.S. Army Tank Automotive and Armaments Command (TACOM) Ride Motion Simulator (RMS) to assess the effects of vertical ride motion on the kinematics of reaching. The RMS was programmed to produce 0.5 g and 0.8 g peak-to-peak sinusoidal inputs at the seat-sitter interface over a range of frequencies. Two participants performed seated reaching tasks to locations typical of in-vehicle controls under static conditions and with single-frequency inputs between 0 and 10 Hz. The participants also held terminal reach postures during 0.5 to 32 Hz sine sweeps. Reach kinematics were recorded using a 10-camera VICON motion capture system. The effects of vertical ride motion on movement time, accuracy, and subjective responses were assessed.

This paper discusses the cooperative research and development work between Delphi Automotive Systems (formerly known as Delphi Interior & Lighting Systems) and the U.S. Army TACOM/TARDEC. Discussion will focus on past work and the evolution of the approaches currently being used by TARDEC and Delphi for digital human animation, real-time human interaction (man in the loop), and motion data library development, as it relates to TACOM/Delphi's electromagnetic motion capture systems and the Engineering Animation Incorporated (EAI)-Jack ergonomic analysis/animation software.