The article describes the main stages of developing a robotic system for the rehabilitation of the lower limbs based on the “tripteron” robot. The structure of a robotic system has been designed, consisting of a 3-PRRR parallel mechanism, which provides the angles of rotation of all joints of the patient’s leg required for rehabilitation and a passive orthosis for supporting the limb. At the first stage, the positions of the active mechanism links are determined. The output link of only one kinematic chain, making a translational movement in the vertical direction, will experience a maximum load. A design diagram of this kinematic chain was built, and the reactions of the supports were determined at the second stage. At the third stage, kinematic dependences were obtained, and an engine was selected that would provide the required torque at the required speeds.

One of the most actual and complex problems of medicine and neurology is the rehabilitation of patients. Robotic systems currently occupy an important place in the comprehensive rehabilitation of neurological patients with severe motor impairment of various etiologies, as well as the most socially significant and common neurological diseases. The article discusses various architectures of robotic systems for the rehabilitation of the lower limbs. The article also analyzes the work of foreign scientists who deal with these issues. As a result, a classification of rehabilitation systems has been compiled and reviewed. The structure of the rehabilitation system based on a passive orthosis and active parallel 3-PRRR robot is proposed. A numerical algorithm has been developed to determine the workspace of a 3-PRRR robot, taking into account design limitations. The algorithm is based on the concept of non-uniform coverings using interval analysis methods and is implemented in the C++ programming language. The results of computational experiments are presented. The simulation results are visualized by converting a set of three-dimensional parallelepipeds into an STL file. However, many areas remain open to theoretical research. A further area of research is the optimization of the geometric parameters of the system for carrying out rehabilitation procedures.

The paper proposes the structure of the robotic system (RS) control system with and without the patient’s force feedback, describes the conditions for using each of them. The method for improving data reliability on applied forces using strain gauge readings in the absence of patient activity was developed. The method of motivating a patient to perform “correct” movements thus “assisting” the mechanism, which consists in changing the speed of movement to create an impression that the mechanism moves due to patient’s efforts was developed. Mathematical RS model was constructed, graphs reflecting the accuracy of the specified trajectory were obtained.