Energy Efficient Autonomous Lower Limb Exoskeleton for Human Motion Enhancement
The paper describes conceptual design, control strategies, and partial simulation for a new fully autonomous lower limb wearable exoskeleton system for human motion enhancement that can support its weight and increase strength and endurance. Various problems still remain to be solved where the most important is the creation of a power and cost efficient system that will allow an exoskeleton to operate for extended period without batteries being frequently recharged. The designed exoskeleton is enabling to decouple the weight/mass carrying function of the system from the forward motion function which reduces the power and size of propulsion motors and thus the overall weight, cost of the system. The decoupling takes place by blocking the motion at knee joint by placing passive air cylinder across the joint. The cylinder is actuated when the knee angle has reached the minimum allowed value to bend. The value of the minimum bending angle depends on usual walk style of the subject. The mechanism of the exoskeleton features a seat to rest the subject’s body weight at the moment of blocking the knee joint motion. The mechanical structure of each leg has six degrees of freedom: four at the hip, one at the knee, and one at the ankle. Exoskeleton legs are attached to subject legs by using flexible cuffs. The operation of all actuators depends on the amount of pressure felt by the feet pressure sensors and knee angle sensor. The sensor readings depend on actual posture of the subject and can be classified in three distinct cases: subject stands on one leg, subject stands still on both legs and subject stands on both legs but transit its weight from one leg to other. This exoskeleton is power efficient because electrical motors are smaller in size and did not participate in supporting the weight like in all other existing exoskeleton designs.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1339432Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1029
 Zoss, A.B., Kazerooni, H. & Chu, A., “Biomechanical design of the Berkeley lower extremity exoskeleton (BLEEX),” IEEE/ASME Transactions on Mechatronics, 11(2), pp. 128–138. 2006.
 K. Suzuki, G. Mito, H. Kawamoto, Y. Hasegawa, Y. Sankai, “Intention-based walking support for paraplegia patients with robot suit HAL,” Journal of Advanced Robotics, 21, pp. 1441-1469, 2007.
 Y. Mao, S. K. Agrawal, “Design of a Cable Driven Arm Exoskeleton (CAREX) for Neural Rehabilitation”, IEEE Transactions on Robotics, vol. 28, no. 4, pp. 922-931, 2012.
 P. K. Jamwal, Q. X. Sheng, H. Shahid, G. P. John, “An adaptive wearable parallel robot for the treatment of ankle injuries,” IEEE/ASME Transactions on Mechatronics, 19(1), pp. 64-75, 2014.
 J. Iqbal, K. Baizid, “Stroke rehabilitation using exoskeleton-based robotic exercisers,” Mini Review, Biomedical Research, 26 (1), pp. 197-201, 2015.
 J. L. Pons, Wearable Robots: Bio-mechatronic Exoskeletons, Wiley & Sons, Ltd.: Hoboken, NJ, USA. 2008.
 De Santis, B. Siciliano, A. De Luca, A. Bicchi, “An atlas of physical human-robot interaction,” Mechanisms and Machines Theory,” vol. 43, pp. 253-270, 2008.
 J. F. Veneman, R. Kruidhof, E. E. Hekman, R. Ekkelenkamp, E. H. Van Asseldonk, H. van der Kooij, “Design and evaluation of the LOPES exoskeleton robot for interactive gait rehabilitation,” IEEE Trans. on Neural Systems and Rehabilitation Engineering, vol. 15, pp. 379-86, 2007.
 S. Banala, S. Agrawal, J. Scholz, “Robot assisted gait training with active leg exoskeleton (ALEX),” IEEE Trans. Neural Syst. Rehabilitation Engineering., vol. 17, pp. 2-8, 2009.
 H. Kawamoto, Y. Sankai, “Power assists method based on phase sequence and muscle force condition for HAL,” Journal of Advanced Robotics, 19(7), pp. 717–734, 2005.
 T. Kawabata, H. Satoh, Y. Sankai, “Working posture control of robot suit HAL for reducing structural stress,” in Proc. of IEEE International Conference on Robotics and Biomimetics (ROBIO), , Guilin, 2009, pp. 2013–2018.
 P. Kao, D. P. Ferris, “Motor adaptation during dorsiflexion-assisted walking with a powered orthosis,” Journal of Gait Posture., vol. 29, pp. 230-236, 2009.
 H. Kazerooni, R. Steger, L. Huang, “Hybrid control of the Berkeley lower extremity exoskeleton (bleex),” The International Journal of Robotics Research, 25(5-6), pp. 561–573, 2006.
 J. Ghan, H. Kazerooni, “System identification for the Berkeley lower extremity exoskeleton (BLEEX),” In Proc. of IEEE International Conference on Robotics and Automation (ICRA), Florida, 2006, pp. 3477–3484.
 C. Heng, Z. Jun, X. Chunming, Z. Hong, C. Xiao, W. Yu, “Design and Control of a Hydraulic-Actuated Leg Exoskeleton for Load-Carrying Augmentation,” in Proc. Of IEEE International Conference on Intelligent Robotics and Automation (ICIRA), Part I, vol. 6424, Shanghai, 2010, pp. 590–599.
 C. J. Walsh, D. Paluska, “Development of a lightweight, underactuated exoskeleton for load-carrying augmentation,” in Proc. of IEEE International Conference on Robotics and Automation (ICRA), Florida, 2006, pp. 3485–3491.
 Y. Ikeuchi, J. Ashihara, Y. Hiki, H. Kudoh, T. Noda, “Walking assist device with bodyweight support system,” in Proc. of IEEE/RSJ International Conference on Intelligent Robots and Systems, St. Louis, 2009, pp. 4073–4079.
 M. Leslie, “The next generation of exoskeletons,” A Magazine of the IEEE Engineering in Medicine and Biology Society, vol. 3, no. 4, pp. 56-61, 2012.
 H. B. Tawakal, M. Adnan, I. Javaid, I. Umer, S. K. Umer, “Kinematic and dynamic Analysis of Lower Limb Exoskeleton,” World Academy of Science, Engineering and Technology International Journal of Mechanical, Aerospace, Industrial, Mechatronic and Manufacturing Engineering, vol.6, no.9, pp. 1945-1949, 2012.