In recent times, several control engineers have been working towards development of efficient rehabilitation exoskeletons for mobility impairments. This work aims at implementation of an optimal fuzzy logic-based control strategy for a lower limb exoskeleton application wherein the control parameters for the proposed control approach are obtained by a recently developed optimization technique named as dragon fly algorithm (DFA). For analysis of appropriately tuned closed-loop control, a comparative study between two optimization techniques namely DFA and genetic algorithm (GA) applied to a 2-degree of freedom (dof) nonlinear and coupled lower-limb exoskeleton, is presented. To see the practical aspects, a three-dimensional simscape model of the 4-dof lower limb exoskeleton is developed to observe the closed-loop performance of fuzzy logic proportional–integral–derivative (FLC-PID) controller for bipedal human walking. Experimental data for different speeds during treadmill walking is captured with electronic wireless goniometer, and is used to validate the bipedal walking control for the designed lower-limb exoskeleton. The results are further compared with traditional PID controllers in order to see the effectiveness of the proposed control approaches. Furthermore, the robustness testing of the proposed control schemes is also investigated for different speeds of human walking. This study presents a closed-loop control design for the development of a low-cost lower limb exoskeleton to restore normal gait for persons with mobility disorders, stroke or elderly persons.

最近，几位控制工程师一直在致力于开发用于行动不便的高效康复外骨骼。这项工作的目的是为下肢外骨骼应用实现基于最优模糊逻辑的控制策略，其中，通过最近开发的名为“蜻蜓算法”（DFA）的优化技术来获得所建议控制方法的控制参数。为了分析适当调整的闭环控制，提出了两种优化技术之间的比较研究，即DFA和应用于2自由度（dof）非线性和耦合下肢外骨骼的遗传算法（GA）。要了解实际情况，建立了一个4 dof下肢外骨骼的三维simscape模型，以观察模糊逻辑比例-积分-微分（FLC-PID）控制器对双足人步行的闭环性能。跑步机步行过程中不同速度的实验数据通过电子无线测角仪捕获，并用于验证设计的下肢外骨骼的双足步行控制。将结果与传统PID控制器进行了进一步比较，以了解所提出的控制方法的有效性。此外，还针对不同的人类步行速度研究了所提出的控制方案的鲁棒性测试。这项研究提出了一种闭环控制设计，用于开发低成本的下肢外骨骼，以恢复行动不便者的正常步态，