Lower limb exoskeletons are a staple in military research because they allow soldiers to carry heavy loads without enduring the weight. The existing lower limb exoskeletons are either gas or battery powered and therefore are not practical for extended periods of time. The LEX (UCSC’s Lower Limb Exoskeleton) is designed to actuate based off of recycled pneumatic energy, which will allow for no time constraints. The human walking (gait) cycle consists of controlled falls which are essentially forward momentum. The knee acts as a damper and absorbs energy created from these falls to prevent it from fracturing bones [1]. The LEX utilizes this energy storage technique by compressing air cylinders at the knee and ankle joints upon flexion and storing the harvested energy in a reservoir tank. The pressurized air is then released into the hip and ankle joints to propel the exoskeleton forward. There are six cylinders total, one in each hip, knee, and ankle joint. Based off of force, angle, and pressure sensors, voltage controlled solenoid valves direct the flow of pressurized air at respective time intervals.

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The development of actuators with enhanced capabilities is critical to the achievement of sensory feedback systems for intuitive, real time human operations of telerobotic systems. The objective of this research project is to continue development of new actuators using active materials which will enhance the capabilities of dexterous, exoskeletal feedback systems for telerobotic applica-tions. In Phase I, feasibility of novel Terfenol-D driven actuators was demonstrated. The new actuators are efficient, responsive, small and exert relatively high forces. The actuators provide proportional forces and are easily interfaced with digital electronics because of low voltage requirements. Phase II will pursue advanced development of proportional force resist ive brake actuators and active linear actuators. The actuator designs will be optimized, fabricated and integrated into a digitally controllable exoskeleton demonstration test bed.

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Research shows that Indian School Children carry up to 8 kg of backpack to school everyday. This study will see the effect of prolonged carriage of the backpack on the autonomic nervous system response, posture and other body deformations. Also, to determine the dimensions of the school backpacks and to identify the methods of carrying bags by school children.

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Current motion tracking technologies fail to provide accurate wide area tracking of multiple users without interference and occlusion problems. These limitations make difficult the construction of a practical and intuitive interface, which allows humans to be inserted into networked virtual environments in a fully immersive manner. Advances in the field of miniature sensors make possible inertial/magnetic tracking of human body limb segment orientation without the limitations of current systems. Due to implementation challenges, inertial/magnetic sensors have not previously been used successfully for full bodymotion capture. This research proposes to overcome these challenges using multi-axis sensors combined with a quaternion-based complementary filter algorithm capable of continuously correcting for drift and following motion through all orientations without singularities. Primarily, this research involves the development of a prototype tracking system to demonstrate the feasibility of hybrid RF/magnetic/inertial motion tracking. Construction of inertial/magnetic (MARG) sensors is completed using off-the-shelf components. Mathematical analysis and computer simulation are used to validate the correctness of the complementary filter algorithm. The implemented human body model utilizes the worldcoordinate reference frame orientation data provided in quaternion form by the complementary filter and orients each limb segment independently. Calibration of the model and the inertial sensors is accomplished using simple but effective algorithms. Physical experiments demonstrate the utility of the proposed system. These experiments involve the tracking of human limbs in real-time using multiple inertial sensors. The motion tracking system produced has an accuracy which is comparable and a latency which is superior to active electro-magnetic sensors. The system is “sourceless” and does not suffer from range restrictions and interference problems. With additional MARG sensor packages, the architecture produced will easily scale to full body tracking. This new technology overcomes the limitations of motion tracking technologies currently vi in use. It will provide wide area tracking of multiple users in virtual environment and augmented reality applications.

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The Defense Advanced Research Project Agency (DARPA) funded the BLEEX project in 2000. Last November, U.C. Berkeley’s Human Engineering and Robotics Laboratory, successfully demonstrated the first experimental Exoskeleton in which the pilot (i.e., the wearer) could carry a heavy load, while feeling only a few-pound load.

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