Bio-Inspired Design and Iterative Feedback Tuning Control of a Wearable Ankle Rehabilitation Robot

2016 ◽  
Vol 16 (4) ◽  
Author(s):  
Liang Zhou ◽  
Wei Meng ◽  
Charles Z. Lu ◽  
Quan Liu ◽  
Qingsong Ai ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Control Method ◽  
Real Life ◽  
Ankle Injuries ◽  
Rehabilitation Robot ◽  
Robotic Rehabilitation ◽  
Robot Controller ◽  
Model Free ◽  
Ankle Rehabilitation ◽  
Iterative Feedback

Robotic rehabilitation for ankle injuries offers several advantages in terms of precision, force accuracy, and task-specific training. While the existing platform-based ankle rehabilitation robots tend to provide a rotation center that does not coincide with the actual ankle joint. In this paper, a novel bio-inspired ankle rehabilitation robot was designed, which is wearable and can keep the participant's shank be stationary. The robot is redundantly actuated by four motors in parallel to offer three ankle rotation degrees-of-freedom (DOFs) with sufficient range of motion (ROM) and force capacity. To control the robotic rehabilitation device operated in a repetitive trajectory training manner, a model-free robust control method in form of iterative feedback tuning (IFT) is proposed to tune the robot controller parameters. Experiments were performed on the parallel ankle rehabilitation platform to investigate the efficacy of the design and the robustness of the IFT technique under real-life rehabilitation scenarios.

scholarly journals Design and Workspace Analysis of a Parallel Ankle Rehabilitation Robot (PARR)

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Leiyu Zhang ◽  
Jianfeng Li ◽  
Mingjie Dong ◽  
Bin Fang ◽  
Ying Cui ◽  
...  
Keyword(s):  
Ankle Joint ◽  
Information Acquisition ◽  
Degrees Of Freedom ◽  
Goodness Of Fit ◽  
Kinematic Model ◽  
Complete Information ◽  
Physical Structure ◽  
Foot Drop ◽  
Rehabilitation Robot ◽  
Ankle Rehabilitation

The ankle rehabilitation robot is essential equipment for patients with foot drop and talipes valgus to make up deficiencies of the manual rehabilitation training and reduce the workload of rehabilitation physicians. A parallel ankle rehabilitation robot (PARR) was developed which had three rotational degrees of freedom around a virtual stationary center for the ankle joint. The center of the ankle should be coincided with the virtual stationary center during the rehabilitation process. Meanwhile, a complete information acquisition system was constructed to improve the human-machine interactivity among the robot, patients, and physicians. The physiological motion space (PMS) of ankle joint in the autonomous and boundary elliptical movements was obtained with the help of the RRR branch and absolute encoders. The natural extreme postures of the ankle complex are the superposition of the three typical movements at the boundary motions. Based on the kinematic model of PARR, the theoretical workspace (TWS) of the parallel mechanism was acquired using the limit boundary searching method and could encircle PMS completely. However, the effective workspace (EWS) was smaller than TWS due to the physical structure, volume, and interference of mechanical elements. In addition, EWS has more clinical significance for the ankle rehabilitation. The PARR prototype satisfies all single-axis rehabilitations of the ankle and can cover most compound motions of the ankle. The goodness of fit of PMS can reach 93.5%. Hence, the developed PARR can be applied to the ankle rehabilitation widely.

Research Status on Ankle Rehabilitation Robot

2019 ◽  
Vol 12 (2) ◽  
pp. 104-124
Author(s):  
Jingang Jiang ◽  
Zhaowei Min ◽  
Zhiyuan Huang ◽  
Xuefeng Ma ◽  
Yihao Chen ◽  
...  
Keyword(s):  
Structure Type ◽  
Ankle Injuries ◽  
Pneumatic Cylinder ◽  
Future Research ◽  
Rehabilitation Robot ◽  
Rehabilitation Training ◽  
Rehabilitation Robots ◽  
Number Of Patients ◽  
Ankle Rehabilitation ◽  
Training Mode

Background: Ankle is an important bearing joint in the human body. Unreasonable exercise patterns and exercise intensity can cause ankle injuries. This will seriously affect patients’ daily life. With the increase in the number of patients, the labor intensity of doctors is increasing. Ankle rehabilitation robot can help doctors free themselves from repetitive tasks, which is, of more practical value. Objective: To give a general summary of recent ankle rehabilitation robot and introduce the respective characteristics and development including structure type, drive type and rehabilitation training mode. Methods: This paper investigates various representative studies related to the ankle rehabilitation robot. The structure type, drive type, rehabilitation training mode and applications situation of these ankle rehabilitation robot are discussed. Results: The characteristics of different types of ankle rehabilitation robots are analyzed. This paper analyzes the main problems in its development. The solutions to the issues and the current and future research on ankle rehabilitation robot are discussed. Conclusion: The ankle rehabilitation robots are classified into motor drive type, pneumatic artificial muscle and pneumatic cylinder drive type and others. Further improvements are needed in the aspects of mechanical design, safety, virtual reality, brain-computer interface, control strategies and algorithm of bio-syncretic mechanism system of ankle rehabilitation robot. More related patents about ankle rehabilitation robot need to be developed.

Adaptive Impedance Control of Parallel Ankle Rehabilitation Robot

2017 ◽  
Vol 139 (11) ◽  
Author(s):  
Prashant K. Jamwal ◽  
Shahid Hussain ◽  
Mergen H. Ghayesh ◽  
Svetlana V. Rogozina
Keyword(s):  
Ankle Joint ◽  
Degrees Of Freedom ◽  
Impedance Control ◽  
Control Strategies ◽  
Active Participation ◽  
Rehabilitation Robot ◽  
Robotic Assistance ◽  
Control Approach ◽  
Ankle Rehabilitation ◽  
Adaptive Impedance Control

Robots are being increasingly used by physical therapists to carry out rehabilitation treatments owing to their ability of providing repetitive, controlled, and autonomous training sessions. Enhanced treatment outcomes can be achieved by encouraging patients' active participation besides robotic assistance. Advanced control strategies are required to be designed and implemented for the rehabilitation robots in order to persuade patients to contribute actively during the treatments. In this paper, an adaptive impedance control approach is developed and implemented on a parallel ankle rehabilitation robot. The ankle robot was designed based on a parallel mechanism and actuated using four pneumatic muscle actuators (PMAs) to provide three rotational degrees-of-freedom (DOFs) to the ankle joint. The proposed controller adapts the parallel robot's impedance according to the patients' active participation to provide customized robotic assistance. In order to evaluate performance of the proposed controller, experiments were conducted with stroke patients. It is demonstrated from the experimental results that the robotic assistance decreases as a result of patients' active participation. Similarly, increased robotics assistance is recorded in response to decrease in patient's participation in the rehabilitation process. This work will aid in the further development of customized robot-assisted physical therapy of ankle joint impairment.

scholarly journals Towards Optimal Platform-Based Robot Design for Ankle Rehabilitation: The State of the Art and Future Prospects

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Qing Miao ◽  
Mingming Zhang ◽  
Congzhe Wang ◽  
Hongsheng Li
Keyword(s):  
Degrees Of Freedom ◽  
English Language ◽  
Gait Training ◽  
Robot Design ◽  
Rehabilitation Robot ◽  
Parallel Mechanisms ◽  
Robot Assisted ◽  
Ankle Rehabilitation ◽  
Keywords Ankle ◽  
New Research

This review aims to compare existing robot-assisted ankle rehabilitation techniques in terms of robot design. Included studies mainly consist of selected papers in two published reviews involving a variety of robot-assisted ankle rehabilitation techniques. A free search was also made in Google Scholar and Scopus by using keywords “ankle∗,” and “robot∗,” and (“rehabilitat∗” or “treat∗”). The search is limited to English-language articles published between January 1980 and September 2016. Results show that existing robot-assisted ankle rehabilitation techniques can be classified into wearable exoskeleton and platform-based devices. Platform-based devices are mostly developed for the treatment of a variety of ankle musculoskeletal and neurological injuries, while wearable ones focus more on ankle-related gait training. In terms of robot design, comparative analysis indicates that an ideal ankle rehabilitation robot should have aligned rotation center as the ankle joint, appropriate workspace, and actuation torque, no matter how many degrees of freedom (DOFs) it has. Single-DOF ankle robots are mostly developed for specific applications, while multi-DOF devices are more suitable for comprehensive ankle rehabilitation exercises. Other factors including posture adjustability and sensing functions should also be considered to promote related clinical applications. An ankle rehabilitation robot with reconfigurability to maximize its functions will be a new research point towards optimal design, especially on parallel mechanisms.

Impedance Control Based Sliding Mode for Lower Limb Rehabilitation Robot

2014 ◽  
Vol 672-674 ◽  
pp. 1770-1773 ◽  
Author(s):  
Fu Cheng Cao ◽  
Li Min Du
Keyword(s):  
Dynamic Response ◽  
Sliding Mode Control ◽  
Lower Limb ◽  
Control Method ◽  
Sliding Mode ◽  
Impedance Control ◽  
Rehabilitation Robot ◽  
Active Rehabilitation ◽  
Limb Rehabilitation ◽  
Lower Limb Rehabilitation

Aimed at improving the dynamic response of the lower limb for patients, an impedance control method based on sliding mode was presented to implement an active rehabilitation. Impedance control can achieve a target-reaching training without the help of a therapist and sliding mode control has a robustness to system uncertainty and vary limb strength. Simulations demonstrate the efficacy of the proposed method for lower limb rehabilitation.

scholarly journals A 4-DOF Upper Limb Exoskeleton for Physical Assistance: Design, Modeling, Control and Performance Evaluation

2021 ◽  
Vol 11 (13) ◽  
pp. 5865
Author(s):  
Muhammad Ahsan Gull ◽  
Mikkel Thoegersen ◽  
Stefan Hein Bengtson ◽  
Mostafa Mohammadi ◽  
Lotte N. S. Andreasen Struijk ◽  
...  
Keyword(s):  
Upper Limb ◽  
Tracking Control ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Mechanical Design ◽  
Trajectory Tracking Control ◽  
Upper Limb Exoskeleton ◽  
And Performance ◽  
Physically Disabled People ◽  
Human Upper Limb

Wheelchair mounted upper limb exoskeletons offer an alternative way to support disabled individuals in their activities of daily living (ADL). Key challenges in exoskeleton technology include innovative mechanical design and implementation of a control method that can assure a safe and comfortable interaction between the human upper limb and exoskeleton. In this article, we present a mechanical design of a four degrees of freedom (DOF) wheelchair mounted upper limb exoskeleton. The design takes advantage of non-backdrivable mechanism that can hold the output position without energy consumption and provide assistance to the completely paralyzed users. Moreover, a PD-based trajectory tracking control is implemented to enhance the performance of human exoskeleton system for two different tasks. Preliminary results are provided to show the effectiveness and reliability of using the proposed design for physically disabled people.

scholarly journals Dealing with multiple experts and non-stationarity in inverse reinforcement learning: an application to real-life problems

2021 ◽  
Author(s):  
Amarildo Likmeta ◽  
Alberto Maria Metelli ◽  
Giorgia Ramponi ◽  
Andrea Tirinzoni ◽  
Matteo Giuliani ◽  
...  
Keyword(s):  
Reinforcement Learning ◽  
Real World ◽  
Real Life ◽  
User Preferences ◽  
Inverse Reinforcement Learning ◽  
Water Release ◽  
Reward Function ◽  
Model Free ◽  
Conflicting Objectives ◽  
Multiple Experts

AbstractIn real-world applications, inferring the intentions of expert agents (e.g., human operators) can be fundamental to understand how possibly conflicting objectives are managed, helping to interpret the demonstrated behavior. In this paper, we discuss how inverse reinforcement learning (IRL) can be employed to retrieve the reward function implicitly optimized by expert agents acting in real applications. Scaling IRL to real-world cases has proved challenging as typically only a fixed dataset of demonstrations is available and further interactions with the environment are not allowed. For this reason, we resort to a class of truly batch model-free IRL algorithms and we present three application scenarios: (1) the high-level decision-making problem in the highway driving scenario, and (2) inferring the user preferences in a social network (Twitter), and (3) the management of the water release in the Como Lake. For each of these scenarios, we provide formalization, experiments and a discussion to interpret the obtained results.

Anti-noise model-free adaptive control and its application in the circulating fluidized bed boiler

2020 ◽  
pp. 095965182097937
Author(s):  
Na Dong ◽  
Wenjin Lv ◽  
Shuo Zhu ◽  
Donghui Li
Keyword(s):  
Adaptive Control ◽  
Complete Convergence ◽  
Circulating Fluidized Bed ◽  
Control Method ◽  
Noise Model ◽  
Good Resistance ◽  
Industrial Systems ◽  
Noise Interference ◽  
Model Free ◽  
Tracking Differentiator

Model-free adaptive control has been developed greatly since it was proposed. Up to now, model-free adaptive control theory has become mature and tends to be an effective solution for complex unmodeled industrial systems. In practical industrial processes, most control systems are inevitably accompanied by noise that will result in indelible error and may further cause inaccurate feedback to the output. In order to solve this kind of problem with model-free technique, this article incorporates an improved tracking differentiator into model-free adaptive control. After that, the anti-noise model-free adaptive control method with complete convergence analysis is proposed. Meanwhile, numerical simulation proves that the improved control method can quickly track a given signal with good resistance to noise interference. Finally, the effectiveness and practicability of the proposed algorithm are verified by experiments through the control of drum water level of circulating fluidized.

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