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# Development of a Human-Machine System in the Form of a Person in a Passive Exoskeleton with Two Types of Spring Elements

Borisov AV*

The Smolensk Branch of Moscow Power Engineering Institute (Technical University), Russia

*Corresponding author: Borisov AV, The Smolensk Branch of Moscow Power Engineering Institute (Technical University), Russia

Submission: December 05, 2020; Published: February 26, 2021

ISSN 2637-8019
Volume3 Issue3

#### Introduction

The proposed model of the protective passive exoskeleton with spring elements addresses the following problems: autonomous working of exoskeleton while keeping some of the advantages of active exoskeletons and increasing the user comfort, unloading the human musculoskeletal system and protecting it. The proposed model differs from the existing [1- 3] ones by the availability of variable-length links [4-6]. These links enhance the comfort of the user operating the exoskeleton and make this operation more energy-efficient as the exoskeleton features the energy recuperators of two types: torsion and compression springs. These features make the consumer properties of passive exoskeletons close to those of active exoskeletons, although the designs of the former ones are simpler and cheaper.

#### The Problem Formulation

The following should be done to solve the problem of simulating the motion of a person in a passive exoskeleton with spring elements of two types:
A. Build the system of differential equations of motion for the model shown on the Figure 1.

Figure 1:2-D model of passive exoskeleton with spring elements and angles calculated between the links.

B. Solve the Cauchy problem numerically for the derived system of differential equations of motion taking into account the exoskeleton mass and the given control based on the empirical information [5].
C. For a visual estimation of the obtained motion of the humanmachine robotic system as a person in exoskeleton, synthesize the animated visualization of the motion for the developed model based on the numerical solution of the Cauchy problem.

#### Numerical Simulation of the Dynamics of the Passive Exoskeleton with Spring Elements

The system of differential equations of the mechanism motion similarly as it is described in the [4,5]. In the vector-matrix record it keeps the form (1), however, the matrices included into this equation become more cumbersome than in the case when the angles are calculated from the horizontal [4,5]. The matrix subscripts designate the corresponding generalized coordinate: k = 1, 2, here 1 corresponds to the generalized coordinate j, 2 - corresponds to the generalized coordinate ξ

Figure 2:The animated visualization frames of the protective passive exoskeleton motion.

Thus, there is an option to visually evaluate the motion of the proposed model. The Figure 2 illustrates the power of this approach and demonstrates the movements’ adequacy of the robotic human-machine system as a person in the protective exoskeleton.

#### Conclusion

The model of passive exoskeleton with variable-length links and spring elements, in which the angles are calculated between the links, has been proposed. This model is more prospective for building a working exoskeleton in which the controlled change of angles between the links should be implemented. The efficiency of this model, as well as its connection with the previous models, in which the angles are calculated between the links and the horizontal, are demonstrated.

#### References

© 2021 Borisov AV. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and build upon your work non-commercially.

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