scholarly journals Development of a Control System and Functional Validation of a Parallel Robot for Lower Limb Rehabilitation

Actuators ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 277
Author(s):  
Doina Pisla ◽  
Iuliu Nadas ◽  
Paul Tucan ◽  
Stefan Albert ◽  
Giuseppe Carbone ◽  
...  

This paper is focused on the development of a control system, implemented on a parallel robot designed for the lower limb rehabilitation of bedridden stroke survivors. The paper presents the RECOVER robotic system kinematics, further implemented into the control system, which is described in terms of architecture and functionality. Through a battery of experimental tests, achieved in laboratory conditions using eight healthy subjects, the feasibility and functionality of the proposed robotic system have been validated, and the overall performance of the control system has been studied. The range of motion of each targeted joint has been recorded using a commercially available external sensor system. The kinematic parameters, namely the patient’s joints velocities and accelerations have been recorded and compared to the ones obtained using the virtual model, yielding a very small difference between them, which provides a validation of the RECOVER initial design, both in terms of mechanical construction and control system.

Author(s):  
Bogdan Gherman ◽  
Iosif Birlescu ◽  
Paul Tucan ◽  
Calin Vaida ◽  
Adrian Pisla ◽  
...  

As the life span increases and the availability of physicians becomes more and more scarce, robotic rehabilitation for post-stroke patients becomes more and more demanding, especially due to the repeatability character of the rehabilitation exercises. Both lower and upper limb rehabilitation using robotic systems have proved to be very successful in different stages of the rehabilitation process, but only a few address the immediate (critical) post-stroke phase, especially when the patient is hemiplegic and is unable to stand. The paper presents the kinematic modelling, singularity analysis and gait simulation for a new 4-DOF parallel robot named RECOVER used for lower limb rehabilitation for bedridden patients. The robotic system has been designed for the mobilization of the lower limb, namely the following motions: the hip and knee flexion and the plantar adduction/abduction and flexion/dorsiflexion. The kinematics has been studied and the singularity configurations have been determined to achieve a failsafe rehabilitation robot. Numerical simulations prove that the system can be used for gait training exercises in safe conditions.


2020 ◽  
Vol 20 (10) ◽  
pp. 2040037
Author(s):  
YAN-LIN WANG ◽  
KE-YI WANG ◽  
ZI-XING ZHANG ◽  
LIANG-LIANG CHEN ◽  
ZONG-JUN MO

Cable-driven parallel robots (CDPR) have been well used in the rehabilitation field. However, the cables can provide the tension in a single direction, there is a pseudo-drag phenomenon of the cables in the CDPR, which will have a great impact on the safety of patients. Therefore, the novelty of this work is that a bionic muscle cable is used to replace the ordinary cable in the CDPR, which can solve the pseudo-drag phenomenon of the cables in the CDPR and improve the safety performance of the rehabilitation robot. The cable-driven lower limb rehabilitation robot with bionic muscle cables is called as the bionic muscle cable-driven lower limb rehabilitation robot (BMCDLR). The motion planning of the rigid branch chain of the BMCDLR is studied, and the dynamics and system stiffness of the BMCDLR are analyzed based on the man–machine model in this paper. The influence of the parameters of the elastic elements in the bionic muscle cables on the mechanical characteristics of the BMCDLR system was analyzed by using simulation experiments. The research results can provide a reference basis for research on the safety evaluation and control methods of the BMCDLR system.


Author(s):  
Jian Li ◽  
Diansheng Chen ◽  
Chunjing Tao ◽  
Hui Li

Purpose Many studies have shown that rehabilitation robots are crucial for lower limb dysfunction, but application of many robotics have yet to be seen to actual use in China. This study aimed to improve a lower limb rehabilitation robot by details improving and practical design. Design/methodology/approach Structures and control system of a lower limb rehabilitation robot are improved in detail, including joint calculations, comfort analysis and feedback logic creation, and prototype experiments on healthy individuals and patients are conducted in a hospital. Findings All participating subjects did not experience any problems. The experiment shows detail improving is reasonable, and feasibility of the robot was confirmed, which has potential for overcoming difficulties and problems in practical application. Research limitations/implications Therapeutic effects need to be evaluated in the future. Also, more details should be improved continuously based on the actual demand. Originality/value The improved robot could assist the lower limb during standing or walking, which has significance for practical application and patients in China.


2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Alireza Rastegarpanah ◽  
Mozafar Saadat

The aim of this study is to investigate the performance of a 6-DoF parallel robot in tracking the movement of the foot trajectory of a paretic leg during a single stride. The foot trajectories of nine patients with a paretic leg including both males and females have been measured and analysed by a Vicon system in a gait laboratory. Based on kinematic and dynamic analysis of a 6-DoF UPS parallel robot, an algorithm was developed in MATLAB to calculate the length of the actuators and their required forces during all trajectories. The workspace and singularity points of the robot were then investigated in nine different cases. A 6-DoF UPS parallel robot prototype with high repeatability was designed and built in order to simulate a single stride. Results showed that the robot was capable of tracking all of the trajectories with the maximum position error of 1.2 mm.


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