Development of Gait Training System Powered by Antagonistic Mono-and Bi-Articular Actuators Using Contraction Model Control Scheme

2013 ◽  
Vol 393 ◽  
pp. 525-531 ◽  
Author(s):  
Mohd Azuwan Mat Dzahir ◽  
Tatsuya Nobutomo ◽  
Shin Ichiroh Yamamoto

The use of Pneumatic Muscle Actuator (PMA) in medical robots for rehabilitation has changed due to the requirements for a compliant, light weight and user-friendly robotic system. In this paper, a control system for controlling the bi-articular actuators (PMA) is proposed. Based on the information obtained from the positional input data (hip and knee joint angles), a contraction model is derived using mathematical equations to determine the contraction patterns of antagonistic mono-and bi-articular actuators, and then implemented it into the control system. Anterior and posterior muscle activation levels are introduced into the model to manipulate its magnitude. There are two tests for the control system; first is with antagonistic mono-articular actuators alone; second is along with antagonistic bi-articular actuators. The contraction model control scheme was tested on a healthy subject in a robot assisted walk test, and satisfactory performance was obtained. The result showed that, the cycle time of the gait training system is improved up to 3 seconds gait cycle compared to 5 seconds gait cycle used in previous research. However, a little time shift and inertia occurred when the controller is tested at faster gait cycle time of 2 seconds and 1 second. Thus, the potential field and iterative learning control are suggested to improve the gait cycle of the system.

2019 ◽  
Vol 19 (02) ◽  
pp. 1940018
Author(s):  
ANDY CHIEN ◽  
FU-HAN HSIEH ◽  
CHING HUANG ◽  
FEI-CHUN CHANG ◽  
NAI-HSIN MENG ◽  
...  

One-third of stroke survivors fail to regain independent ambulation and strokes have been identified as a significant source of long-term disability and a tremendous health burden. Robot-assisted gait rehabilitation is gaining traction and advocators for its inclusion as part of the routine post-stroke rehabilitation program are on the increase. However, despite the recent technological advances in the development and design of better robotics, the research evidence on the best model of robotic training remains sparse and unclear. It is therefore the aim of the current study to comparatively investigate the clinical feasibility and efficacy of a recently developed HIWIN Robotic Gait Training System (MRG-P100) combined with the use of a lab-developed MBS-E100 EMG system as a controller on facilitating the development of an appropriate gait pattern for motor impaired subacute stroke patients. The results indicated that due to the heterogeneity of stroke-induced changes in muscle characteristics, an “auto-fit” algorithm was required to allow constant monitoring and updating of the appropriate threshold based on EMG signals captured during previous gait cycle in order to determine the desired muscle activation threshold for the current gait cycle. Eighteen participants were tested using the new auto-fit algorithm and results demonstrated a significantly more fluent and physiologically appropriate gait pattern.


Author(s):  
Ke Li ◽  
Feng Ling ◽  
Xiaodong Sun ◽  
Zebin Yang

In this paper, a novel decoupling control scheme combining least squares support vector machines (LSSVM) inverse models and 2-degree-of-freedom (DOF) internal model controllers is employed in the decoupling control system of the bearingless permanent magnet synchronous motor (BPMSM). This scheme can be used to enhance the control properties of high-precision, fast-response, and strong-robustness for the BPMSM system, and effectively eliminate the nonlinear and coupling influence. It introduces LSSVM inverse models into the original BPMSM system to constitute a decoupled pseudo-linear system. In addition, the particle swarm optimization algorithm (PSO) is used to optimize parameters of the LSSVM, which improves its fitting ability and prediction accuracy. What is more, the internal model control scheme is used to design additional closed-loop controllers, thereby improving the robustness of the entire control system. Therefore, this scheme successfully combines the advantages of the LSSVM inverse models and the internal model controller. It can enhance the stability and the static as well as dynamic properties of the whole BPMSM system while independently adjusting the tracking and interference rejection performances. The effectiveness of the proposed scheme has been verified by simulation results at various operations.


Actuators ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 105
Author(s):  
Thinh Huynh ◽  
Minh-Thien Tran ◽  
Dong-Hun Lee ◽  
Soumayya Chakir ◽  
Young-Bok Kim

This paper proposes a new method to control the pose of a camera mounted on a two-axis gimbal system for visual servoing applications. In these applications, the camera should be stable while its line-of-sight points at a target located within the camera’s field of view. One of the most challenging aspects of these systems is the coupling in the gimbal kinematics as well as the imaging geometry. Such factors must be considered in the control system design process to achieve better control performances. The novelty of this study is that the couplings in both mechanism’s kinematics and imaging geometry are decoupled simultaneously by a new technique, so popular control methods can be easily implemented, and good tracking performances are obtained. The proposed control configuration includes a calculation of the gimbal’s desired motion taking into account the coupling influence, and a control law derived by the backstepping procedure. Simulation and experimental studies were conducted, and their results validate the efficiency of the proposed control system. Moreover, comparison studies are conducted between the proposed control scheme, the image-based pointing control, and the decoupled control. This proves the superiority of the proposed approach that requires fewer measurements and results in smoother transient responses.


2021 ◽  
Vol 11 (14) ◽  
pp. 6299
Author(s):  
Xiong Xie ◽  
Tao Sheng ◽  
Liang He

The distributed attitude synchronization control problem for spacecraft formation flying subject to limited energy and computational resources is addressed based on event-triggered mechanism. Firstly, a distributed event-driven controller is designed to achieve attitude coordination with the limitation of energy and computing resources. Under the proposed control strategy, the controller is only updated at the event triggering instants, which effectively reduces the update frequency. Subsequently, an event-triggered strategy is developed to further decrease energy consumption and the amount of computation. The proposed event-triggered function only requires the latest state information about its neighbors, implying that the trigger threshold does not need to be calculated continuously. It is shown that the triggering interval between two successive events is strictly positive, showing that the control system has no Zeno phenomenon. Moreover, the update frequency of the proposed controller can be reduced by more than 90% compared to the update frequency of the corresponding time-driven controller with an update frequency of 10 Hz by choosing appropriate control parameters and the control system can still achieve high-precision convergence. Finally, the effectiveness of the constructed control scheme is verified by numerical simulations.


Author(s):  
Shihuan Li ◽  
Lei Wang

For L4 and above autonomous driving levels, the automatic control system has been redundantly designed, and a new steering control method based on brake has been proposed; a new dual-track model has been established through multiple driving tests. The axle part of the model was improved, the accuracy of the transfer function of the model was verified again through acceleration-slide tests; a controller based on interference measurement was designed on the basis of the model, and the relationships between the controller parameters was discussed. Through the linearization of the controller, the robustness of uncertain automobile parameters is discussed; the control scheme is tested and verified through group driving test, and the results prove that the accuracy and precision of the controller meet the requirements, the robustness stability is good. Moreover, the predicted value of the model fits well with the actual observation value, the proposal of this method provides a new idea for avoiding car out of control.


Author(s):  
Andy Chien ◽  
Fei-Chun Chang ◽  
Nai-Hsin Meng ◽  
Pei-Yu Yang ◽  
Ching Huang ◽  
...  

Abstract Purpose Robot-assisted gait rehabilitation has been proposed as a plausible supplementary rehabilitation strategy in stroke rehabilitation in the last decade. However, its exact benefit over traditional rehabilitation remain sparse and unclear. It is therefore the purpose of the current study to comparatively investigate the clinical benefits of the additional robot-assisted training in acute stroke patients compared to standard hospital rehabilitation alone. Methods Ninety acute stroke patients (< 3 month) were recruited. All participants received the standard hospital neurorehabilitation comprises 45–60 min sessions daily for 3 weeks. Sixty patients also received an additional 30 min of robot-assisted gait training with the HIWIN MRG-P100 gait training system after each of the standard neurorehabilitation session. Outcome measures included: 1. Berg Balance Scale (BBS); 2. Brunnstrom Stage; 3. Pittsburgh Sleep Quality Index and 4. Taiwanese Depression Questionnaire (TDQ) which were assessed pre-treatment and then after every five training sessions. Results Both groups demonstrated significant improvement pre- and post-treatment for the BBS (robotic group p = 0.023; control group p = 0.033) but no significant difference (p > 0.1) between the groups were found. However, the robotic training group had more participants demonstrating larger BBS points of improvement as well as greater Brunnstrom stage of improvement, when compared to the control group. No significant within and between group statistical differences (p > 0.3) were found for Pittsburgh Sleep Quality Index and Taiwanese Depression Questionnaire. Conclusion The addition of robotic gait training on top of standard hospital neurorehabilitation for acute stroke patients appear to produce a slightly greater improvement in clinical functional outcomes, which is not transferred to psychological status.


2021 ◽  
Vol 11 (4) ◽  
pp. 448
Author(s):  
Francesco Infarinato ◽  
Paola Romano ◽  
Michela Goffredo ◽  
Marco Ottaviani ◽  
Daniele Galafate ◽  
...  

Background: Overground Robot-Assisted Gait Training (o-RAGT) appears to be a promising stroke rehabilitation in terms of clinical outcomes. The literature on surface ElectroMyoGraphy (sEMG) assessment in o-RAGT is limited. This paper aimed to assess muscle activation patterns with sEMG in subjects subacute post stroke after training with o-RAGT and conventional therapy. Methods: An observational preliminary study was carried out with subjects subacute post stroke who received 15 sessions of o-RAGT (5 sessions/week; 60 min) in combination with conventional therapy. The subjects were assessed with both clinical and instrumental evaluations. Gait kinematics and sEMG data were acquired before (T1) and after (T2) the period of treatment (during ecological gait), and during the first session of o-RAGT (o-RAGT1). An eight-channel wireless sEMG device acquired in sEMG signals. Significant differences in sEMG outcomes were found in the BS of TA between T1 and T2. There were no other significant correlations between the sEMG outcomes and the clinical results between T1 and T2. Conclusions: There were significant functional gains in gait after complex intensive clinical rehabilitation with o-RAGT and conventional therapy. In addition, there was a significant increase in bilateral symmetry of the Tibialis Anterior muscles. At this stage of the signals from the tibialis anterior (TA), gastrocnemius medialis (GM), rectus femoris (RF), and biceps femoris caput longus (BF) muscles of each lower extremity. sEMG data processing extracted the Bilateral Symmetry (BS), the Co-Contraction (CC), and the Root Mean Square (RMS) coefficients. Results: Eight of 22 subjects in the subacute stage post stroke agreed to participate in this sEMG study. This subsample demonstrated a significant improvement in the motricity index of the affected lower limb and functional ambulation. The heterogeneity of the subjects’ characteristics and the small number of subjects was associated with high variability research, functional gait recovery was associated with minimal change in muscle activation patterns.


2013 ◽  
Vol 706-708 ◽  
pp. 716-719
Author(s):  
Jian Chu ◽  
Gang Wang

This paper mainly introduced to the PLC as the core of stainless steel composite plate electric control part of the design. The system uses the converter +PLC+ man-machine interface, as the major part of roll welding machine control, because of the use of the PLC, so that the system can improve the automatic level, electrical components is reduced, reduce failure rate, improve the reliability of equipment operation. Based on the current control and speed control, so that the welding quality and welding speed has been greatly improved. In the article, mainly from the production process, and the control system hardware and software design, and the control scheme to introduce several aspects.


Sign in / Sign up

Export Citation Format

Share Document