Modeling Gait Patterns of a Patient with Orthopedic Injury Using an Exoskeleton

Purpose of reseach. The paper describes the EXOLITE-REHAB rehabilitation robotic complex which makes it possible to do rehabilitation exercises of lower limbs of patients by performing leg lifting, verticalization, squats and other types of movement. In many countries, research work is underway to create devices that allow a person to move in space when the musculo-skeletal system is damaged.  Therefore, the purpose of this article is to study and set the basic regularities and algorithms based on mathematical models describing the controlled movement of the lower limbs exoskeleton by the example of modeling the movement of the exoskeleton's ankle joint.

Methods. The key feature of the complex is the use of a follower-up control system that allows us to provide a prescribed movement of the human ankle joint with a high degree of accuracy in a wide range of parameters’ changes. Methods of mathematical modeling of the ankle joint movement are applied, taking into account their subsequent possible use in modeling the movement of exoskeleton links.

Results. A kinematic setting of the ankle joint movement trajectory  is used in order to simulate the operation of a robotic system. In order to find the vector of generalized coordinates, the inverse kinematics problem is solved using the vector-matrix method with the application of Jacobian matrix. The results of numerical simulation show high convergence and adequacy of the proposed method.

Conclusion. The article considers the method of using a follower-up control system that has a sufficient degree of accuracy of copying the trajectory. The results of modeling the follower-up control system of the EXOLITE-REHAB rehabilitation exoskeleton, working according to the developed algorithm, show that it is able to repeat the required trajectory with sufficient accuracy. In the future, we plan to study the system more deeply on a three-dimensional model with electric drives. 

1. Aliseychik A.P. i dr. Mekhanika i upravleniye ekzoskeletami nizhnikh konechnostey dlya neyroreabelitatsii spinal'nykh bol'nykh [Mechanics and control of exoskeletons of the lower extremities for neurorehabitation of spinal patients]. XI Vserossiyskiy s"yezd po fundamental'nym problemam teoreticheskoy i prikladnoy mekhaniki. Sbornik dokladov [XI AllRussian Congress on Fundamental Problems of Theoretical and Applied Mechanics. Collection of reports]. Kazan, 2015, pp. 132-134 (In Russ.).

2. Aliseychik A.P., Orlov I.A., Kolesnichenko Ye.Yu., Pavlovskiy V.Ye., Pavlov- skiy V.V., Platonov A.K. Reabilitatsionnyy ekzoskelet BioMekh: modeli, upravleniye, konstruktsiya. [Rehabilitation exoskeleton BioMech: models, management, design, experiments]. Mechatronics, automation, control]. Mekhatronika, avtomatizatsiya, upravlenie = Mechatronics, Automation, Management, 2016, no. 17(10), pp. 670-677 (In Russ.).

3. Borisov A. V., Rozenblat G. M., Chigarev A. V. Primeneniye matrichnogo metoda i rekurrentnogo algoritma k modeli ploskogo mnogozvennogo mekhanizma so zven'yami peremennoy dliny, dvizhushchegosya po gorizontal'noy ploskosti [Application of the matrix method and the recurrent algorithm to the model of a plane-multipurpose mechanism with lines of variable length moving on a horizontal plane]. Teoreticheskaya i prikladnaya mekhanika. Mezhdunarodnyi nauchno-tekhnicheskii sbornik [Theoretical and applied mechanics. International scientific and technical collection]. Minsk, 2018, vol. 33, pp. 370-380 (In Russ.).

4. Borisov A.V. Mekhanika prostranstvennoy modeli ekzoskeleta i antropomorfnogo robota [The mechanics of the spatial model of the exoskeleton and anthropomorphic robot]. Voprosy oboronnoy tekhniki. Seriya 16: Tekhnicheskiye sredstva prodivodeystviya terrorizmu = Questions of defense technology. Series 16: Technological Tools for Combating Terrorism, 2018. no. 3-4, pp. 46-55 (In Russ.).

5. Domrachev T.B. Yashmetkov K.S. Loskutov Yu.V. Kinematika lokomotsiy cheloveka pri vstavanii iz seda i posadke na oporu [Kinematics of human locomotion when standing up from a gray-haired vehicle and landing on a support]. AEE Avtomatizatsiya v elektroenergetike i elektrotekhnike [AEE Automation in the electric power industry and electrical engineering]. Perm'. Apr. 2016. (In Russ.).

6. Gavrilov S. V., Zang D. T. Komp'yuternoye modelirovaniye dinamiki dvizheniya pyatistepennogo shagayushchego robota [Computer simulation of the dynamics of motion of a five-step walking robot]. Inzhenernye kadry – budushchee innovatsionnoi ekonomiki Rossii = Engineering staff - the future of Russia's innovative economy, 2017, no. 1, pp. 40-42 (In Russ.).

7. Lavrovskiy E.K. Ob energetike pokhodki cheloveka-operatora, osushchestvlyayemoy pri pomoshchi apparata “passivnyy” ekzoskeleton [On the energy of the gait of a human operator, carried out using the apparatus “passive” exoskeleton]. Izvestiya Rossiyskoy akademii nauk. Mekhanika tverdogo tela = News of the Russian Academy of Sciences. Solid mechanics, 2015, no. 1, pp. 9-24 (In Russ.).

8. Contreras-Vidal, Jose L., Robert G. Grossman. "NeuroRex: A clinical neural interface roadmap for EEG-based brain machine interfaces to a lower body robotic exoskeleton." Engineering in medicine and biology society (EMBC), 2013 35th annual international conference of the IEEE. IEEE, 2013.

9. Kiguchi Kazuo, Takakazu Tanaka, and Toshio Fukuda. "Neuro-fuzzy control of a robotic exoskeleton with EMG signals." Fuzzy Systems, IEEE Transactions on 12.4, 2004, pp. 481-490.

10. Kazerooni H, Steger R, Huang L. Hybrid control of the Berkeley lower extremity exoskeleton (BLEEX). The International Journal of Robotics Research. 2006, May 1, no. 25(5-6), pp.561-73.

11. Kazerooni H., Racine JL., Huang L., Steger R. On the control of the Berkeley lower extremity exoskeleton (BLEEX). In Robotics and automation, 2005. ICRA 2005. Proceedings of the 2005 IEEE international conference, 2005, Apr 18, pp. 4353-4360. IEEE.

12. Steger R., Kim SH, Kazerooni H. Control scheme and networked control architecture for the Berkeley lower extremity exoskeleton (BLEEX). InRobotics and Automation, 2006. ICRA 2006. Proceedings 2006 IEEE International Conference on 2006 May 15, pp. 3469-3476. IEEE.

13. Jatsun S., Savin S., Yatsun A., Malchikov A. Study of Controlled Motion of Exoskeleton Moving from Sitting to Standing Position. In Advances in Robot Design and Intelligent Control, 2016, pp. 165-172. Springer International Publishing.

14. Jatsun S., Savin S., Yatsun A., Turlapov R. Adaptive control system for exoskeleton performing sit-to-stand motion. InMechatronics and its Applications (ISMA), 2015 10th International Symposium on 2015 Dec 8, pp. 1-6. IEEE.

15. Vorochaeva L.Yu., Savin S.I., Yatsun A.S. An investigation of motion of a crawling robot with supports with controllable friction В книге: ANS Conference Series: Scientific Heritage of Sergey A. Chaplygin (Nonholonomic Mechanics, Vortex Structures and Hydrodynamics) Book of Abstracts, 2019, pp. 207-209.

16. Jatsun S.F., Yatsun A.S. Criterion of the rehabilitation process effectiveness on the basis of biomehatronic system EXOLITE REHAB В сборнике: Proceedings of IEEE Workshop on Advanced Robotics and its Social Impacts, ARSO Сер. 2018 IEEE Workshop on Advanced Robotics and its Social Impacts, ARSO 2018", 2019, pp. 105-110.

17. Yang W. Structure Design and Dynamic Model Analysis of Multi-degree-offreedom Exoskeleton / W. Yang, Y. Yang, W. Liu, R. Wang. In 2015 International Conference on Mechatronics, Electronic, Industrial and Control Engineering (MEIC-15). Atlantis Press Publ., 2015.

18. Yatsun A., Jatsun S. Modeling quasi-static gait of a person wearing lower limb exoskeleton Lecture Notes in Mechanical Engineering. 2019, № 9783319956299, pp. 565-575.

19. Zoss A.B., Kazerooni H. , Chu A. Biomechanical design of the Berkeley lower extremity exoskeleton (BLEEX). IEEE/ASME Transactions On Mechatronics, 2006, no. 11(2), pp.128-138.

20. Vitiello N., Lenzi T., Roccella S., . De Rossi S. M.M, Cattin E., Giovacchini F., Vecchi F., Carrozza M. NEUROExos: A powered elbow exoskeleton for physical rehabilitation. Robotics, IEEE Transactions on 29, 2013, no. 1, pp.220-235.