Global ETD Search

61	Simulation of an interlocking hydraulic direct-drive system for a biped walking robot Shimizu, Juri, Otani, Takuya, Hashimoto, Kenji, Takanishi, Atsuo 25 June 2020 (has links) Biped robots with serial links driven by an electric motor experience problems because the motor and transmission are installed in each joint, causing the legs to become very heavy. Previous solutions involved robots using servo valves, a type of highly responsive proportional valve. However, high supply pressure is necessary to realize high responsiveness and the resulting energy losses are large. To address this problem, we proposed a hydraulic direct-drive system in which the pump controls the cylinder meter-in flow, while a proportional valve controls the meter-out flow. Furthermore, our hydraulic interlocking drive system connects two hydraulic direct-drive systems for biped humanoid robots and concentrates the pump output on one side cylinder. The meter-in flow rate of the other side cylinder is controlled by the meter-out flow rate of the cylinder on which the pump is concentrated. A comparison of the walking simulation performance with that of the conventional independent system shows that our proposed system reduces the motor output power by 24.3%. These results prove the feasibility of constructing a two-legged robot without having to incorporate highly responsive servo valves. info:eu-repo/classification/ddc/620 ddc:620
62	Predicting ground reaction forces of human gait using a simple bipedal spring-mass model Mauersberger, Michael, Hähnel, Falk, Wolf, Klaus, Markmiller, Johannes F. C., Knorr, Alexander, Krumm, Dominik, Odenwald, Stephan 22 May 2024 (has links) Aircraft design must be lightweight and cost-efficient on the condition of aircraft certification. In addition to standard load cases, human-induced loads can occur in the aircraft interior. These are crucial for optimal design but difficult to estimate. In this study, a simple bipedal spring-mass model with roller feet predicted human-induced loads caused by human gait for use within an end-to-end design process. The prediction needed no further experimental data. Gait movement and ground reaction force (GRF) were simulated by means of two parameter constraints with easily estimable input variables (gait speed, body mass, body height). To calibrate and validate the prediction model, experiments were conducted in which 12 test persons walked in an aircraft mock-up under different conditions. Additional statistical regression models helped to compensate for bipedal model limitations. Direct regression models predicted single GRF parameters as a reference without a bipedal model. The parameter constraint with equal gait speed in experiment and simulation yielded good estimates of force maxima (error 5.3%), while equal initial GRF gave a more reliable prediction. Both parameter constraints predicted contact time very well (error 0.9%). Predictions with the bipedal model including full GRF curves were overall as reliable as the reference. info:eu-repo/classification/ddc/500 ddc:500 info:eu-repo/classification/ddc/600 ddc:600
63	Design of a Pneumatic Artificial Muscle for Powered Lower Limb Prostheses Murillo, Jaime 01 May 2013 (has links) Ideal prostheses are defined as artificial limbs that would permit physically impaired individuals freedom of movement and independence rather than a life of disability and dependence. Current lower limb prostheses range from a single mechanical revolute joint to advanced microprocessor controlled mechanisms. Despite the advancement in technology and medicine, current lower limb prostheses are still lacking an actuation element, which prohibits patients from regaining their original mobility and improving their quality of life. This thesis aims to design and test a Pneumatic Artificial Muscle that would actuate lower limb prostheses. This would offer patients the ability to ascend and descend stairs as well as standing up from a sitting position. A comprehensive study of knee biomechanics is first accomplished to characterize the actuation requirement, and subsequently a Pneumatic Artificial Muscle design is proposed. A novel design of muscle end fixtures is presented which would allow the muscle to operate at a gage pressure surpassing 2.76 MPa (i.e. 400 psi) and yield a muscle force that is at least 3 times greater than that produced by any existing equivalent Pneumatic Artificial Muscle. Finally, the proposed Pneumatic Artificial Muscle is tested and validated to verify that it meets the size, weight, kinetic and kinematic requirements of human knee articulation. PAM Pneumatic Artificial Muscle High power density actuator Powered lower limb prostheses actuator Actuators for robotics and automation Biorobotics Light and powerful actuator Pneumatic actuator in aerospace industry Powered prostheses McKibben muscle Lightweight actuator Compliance Actuator Pneumatic Legged robots Rehabilitation Gait Exoskeleton Locomotion Aerospace actuator Bipedal walking robot
64	Design of a Pneumatic Artificial Muscle for Powered Lower Limb Prostheses Murillo, Jaime January 2013 (has links) Ideal prostheses are defined as artificial limbs that would permit physically impaired individuals freedom of movement and independence rather than a life of disability and dependence. Current lower limb prostheses range from a single mechanical revolute joint to advanced microprocessor controlled mechanisms. Despite the advancement in technology and medicine, current lower limb prostheses are still lacking an actuation element, which prohibits patients from regaining their original mobility and improving their quality of life. This thesis aims to design and test a Pneumatic Artificial Muscle that would actuate lower limb prostheses. This would offer patients the ability to ascend and descend stairs as well as standing up from a sitting position. A comprehensive study of knee biomechanics is first accomplished to characterize the actuation requirement, and subsequently a Pneumatic Artificial Muscle design is proposed. A novel design of muscle end fixtures is presented which would allow the muscle to operate at a gage pressure surpassing 2.76 MPa (i.e. 400 psi) and yield a muscle force that is at least 3 times greater than that produced by any existing equivalent Pneumatic Artificial Muscle. Finally, the proposed Pneumatic Artificial Muscle is tested and validated to verify that it meets the size, weight, kinetic and kinematic requirements of human knee articulation. PAM Pneumatic Artificial Muscle High power density actuator Powered lower limb prostheses actuator Actuators for robotics and automation Biorobotics Light and powerful actuator Pneumatic actuator in aerospace industry Powered prostheses McKibben muscle Lightweight actuator Compliance Actuator Pneumatic Legged robots Rehabilitation Gait Exoskeleton Locomotion Aerospace actuator Bipedal walking robot
65	The Development of the Anterior Inferior Iliac Spine: A Comparative Analysis Among Hominids and African Apes Zirkle, Dexter 27 March 2015 (has links) No description available. Ancient History Archaeology Biology Biomedical Research Cellular Biology Comparative Developmental Biology Endocrinology Forensic Anthropology Forensic Osteology Genetics Morphology Paleontology Physical Anthropology Radiology Sports Medicine Surgery Zoology Biomechanics Evolution and Development Health Sciences Anatomy and Physiology Animals pelvis ilium iliac isthmus anterior inferior iliac spine AIIS anterior spine hominid Ardi Ardipithecus Oreopithecus Pan Gorilla Pongo secondary ossification Lucy Lovejoy Zirkle development morphology ape bipedal anatomy evolution apophysis growth

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