A hybrid active force control of a lower limb exoskeleton for gait rehabilitation

2018 ◽  
Vol 63 (4) ◽  
pp. 491-500 ◽  
Author(s):  
Zahari Taha ◽  
Anwar P.P. Abdul Majeed ◽  
Amar Faiz Zainal Abidin ◽  
Mohammed A. Hashem Ali ◽  
Ismail Mohd Khairuddin ◽  
...  
Keyword(s):  
Force Control ◽  
Lower Limb ◽  
Sagittal Plane ◽  
Joint Space ◽  
Gait Rehabilitation ◽  
Active Force ◽  
Lower Limb Exoskeleton ◽  
Active Force Control ◽  
Increasing Demand ◽  
And Control

Abstract Owing to the increasing demand for rehabilitation services, robotics have been engaged in addressing the drawbacks of conventional rehabilitation therapy. This paper focuses on the modelling and control of a three-link lower limb exoskeleton for gait rehabilitation that is restricted to the sagittal plane. The exoskeleton that is modelled together with a human lower limb model is subjected to a number of excitations at its joints while performing a joint space trajectory tracking, to investigate the effectiveness of the proposed controller in compensating disturbances. A particle swarm optimised active force control strategy is proposed to facilitate disturbance rejection of a conventional proportional-derivative (PD) control algorithm. The simulation study provides considerable insight into the robustness of the proposed method in attenuating the disturbance effect as compared to the conventional PD counterpart without compromising its tracking performance. The findings from the study further suggest its potential employment on a lower limb exoskeleton.

scholarly journals The Control of a Lower Limb Exoskeleton for Gait Rehabilitation: A Hybrid Active Force Control Approach

2017 ◽  
Vol 105 ◽  
pp. 183-190 ◽  
Author(s):  
A.P.P.A. Majeed ◽  
Z. Taha ◽  
A.F.Z. Abidin ◽  
M.A. Zakaria ◽  
I.M. Khairuddina ◽  
...  
Keyword(s):  
Force Control ◽  
Lower Limb ◽  
Gait Rehabilitation ◽  
Active Force ◽  
Control Approach ◽  
Lower Limb Exoskeleton ◽  
Active Force Control

scholarly journals Modal Decoupled Dynamics Feed-Forward Active Force Control of Spatial Multi-DOF Parallel Robotic Manipulator

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Xinjian Niu ◽  
Chifu Yang ◽  
Bowen Tian ◽  
Xiang Li ◽  
Junwei Han
Keyword(s):  
Control Strategy ◽  
Force Control ◽  
Parallel Mechanism ◽  
Control Method ◽  
Intelligent System ◽  
Joint Space ◽  
Active Force ◽  
Feed Forward ◽  
Electric Actuator ◽  
Active Force Control

According to the parallel mechanism theory, this paper proposes a novel intelligent robotic spine brace for the treatment of scoliosis. Nevertheless, this type of parallel mechanism has the following disadvantages: strong dynamic coupling in task space or joint space, adverse effect of system’s gravity, and lower response frequency in roll and pitch orientations, which seriously affect the performance of the system. In order to solve those boring problems, this paper presents a novel active force control structure, modal space dynamic feed-forward (MSDF) force control strategy. Besides, this paper expresses the intelligent robotic brace system model including the dynamic and kinematic models and the electric actuator model with Kane strategy. The stability of the intelligent system with the novel control strategy is proved. In order to evaluate the performance of the presented MSDF force control method, this paper builds the parallel mechanism experimental platform. It can be seen from experimental results that the proposed motion control method solves these boring problems well.

scholarly journals Knowledge-Based Trajectory Error Pattern Method Applied to an Active Force Control Scheme

1970 ◽  
Vol 3 (1) ◽  
Author(s):  
Endra Pitowarno, Musa Mailah, Hishamuddin Jamaluddin
Keyword(s):  
Force Control ◽  
Error Pattern ◽  
Robot Arm ◽  
Active Force ◽  
Trajectory Error ◽  
Track Error ◽  
Knowledge Based ◽  
Inertia Matrix ◽  
Active Force Control ◽  
Control Scheme

The active force control (AFC) method is known as a robust control scheme that dramatically enhances the performance of a robot arm particularly in compensating the disturbance effects. The main task of the AFC method is to estimate the inertia matrix in the feedback loop to provide the correct (motor) torque required to cancel out these disturbances. Several intelligent control schemes have already been introduced to enhance the estimation methods of acquiring the inertia matrix such as those using neural network, iterative learning and fuzzy logic. In this paper, we propose an alternative scheme called Knowledge-Based Trajectory Error Pattern Method (KBTEPM) to suppress the trajectory track error of the AFC scheme. The knowledge is developed from the trajectory track error characteristic based on the previous experimental results of the crude approximation method. It produces a unique, new and desirable error pattern when a trajectory command is forced. An experimental study was performed using simulation work on the AFC scheme with KBTEPM applied to a two-planar manipulator in which a set of rule-based algorithm is derived. A number of previous AFC schemes are also reviewed as benchmark. The simulation results show that the AFC-KBTEPM scheme successfully reduces the trajectory track error significantly even in the presence of the introduced disturbances.Key Words:  Active force control, estimated inertia matrix, robot arm, trajectory error pattern, knowledge-based.

scholarly journals Development of human lower limbs exoskeleton robot for medical rehabilitation

2021 ◽  
pp. 91-97
Author(s):  
E. A. Kotov ◽  
◽  
A. D. Druk ◽  
D. N. Klypin ◽  
◽  
...  
Keyword(s):  
Control System ◽  
Experimental Research ◽  
Lower Limb ◽  
Lower Limbs ◽  
Medical Rehabilitation ◽  
Lower Limb Exoskeleton ◽  
Exoskeleton Robot ◽  
Controlled Motion ◽  
And Control

The article deals with the solution of the problem of optimizing the characteristics of controlled motion of human lower limb exoskeleton robot for improving medical rehabilitation. The aim of the work is to develop a rehabilitation device capable of providing controlled motion in two planes, as well as maintaining balance without loss of mobility. The design and control system of a rehabilitation trainer designed for performing mechanotherapy of the lower limbs of patients with locomotive disorders are proposed and characterized. The developed system has a number of significant differences from analogues and can be recommended for experimental research on patients with impaired locomotive functions

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