scholarly journals Soft Finger Modelling and Co-Simulation Control towards Assistive Exoskeleton Hand Glove

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 181
Author(s):  
Mohammed N. El-Agroudy ◽  
Mohammed I. Awad ◽  
Shady A. Maged
Keyword(s):  
Pid Control ◽  
Closed Loop ◽  
External Disturbance ◽  
Open Loop ◽  
Optimal Parameters ◽  
Concentrated Force ◽  
Pneumatic Actuators ◽  
User Subroutine ◽  
Fortran Code ◽  
Modeling Software

The soft pneumatic actuators of an assistive exoskeleton hand glove are here designed. The design of the actuators focuses on allowing the actuator to perform the required bending and to restrict elongation or twisting of the actuator. The actuator is then modeled using ABAQUS/CAE, a finite element modeling software, and the open loop response of the model is obtained. The parameters of the actuator are then optimized to reach the optimal parameters corresponding to the best performance. Design of experiment (DOE) techniques are then approached to study the robustness of the system. Software-in-the-loop (SiL) is then approached to control the model variables via a proportional-integral-derivative (PID) control generated by FORTRAN code. The link between the two programs is to be achieved by the user subroutine that is written, where the subroutine receives values from ABAQUS/CAE, performs calculations, and passes values back to the software. The controller’s parameters are tuned and then the closed loop response of the model is obtained by setting the desired bending angle and running the model. Furthermore, a concentrated force at the tip of the actuator is added to observe the actuator’s response to external disturbance.

SPWM Inverter Closed-Loop PID Control System

2011 ◽  
Vol 219-220 ◽  
pp. 1367-1370 ◽  
Author(s):  
Ying Chen
Keyword(s):  
Pid Control ◽  
Pid Controller ◽  
Closed Loop ◽  
Digital Simulation ◽  
Open Loop ◽  
Current Loop ◽  
Closed Loop System ◽  
Working Principle ◽  
The Stability ◽  
Power Electronic Technology

Along with the development of power electronic technology, various inverters are widely used in all sectors. the advanced modern control theory and methods have been applied in the inverter, which made the stability and reliability for the inverter have improved greatly. In this paper analyses the working principle for SPWM inverter that used voltage and current cut-loop PID control strategy, in the voltage loop and current loop make use of its transfer function to both no-load and full load conditions for digital simulation, and get different Bode diagrams, meanwhile also analyses the different simulation results for system that without add PID controller and join PID controller, with the analyze results can determine the open-loop frequency characteristics of various parameters for the closed- loop system, and to ensure the output inverter to achieve the intended targets.

Leveraging the Open-Loop Stiffness of Pneumatic Actuators to Enable High-Stiffness Surface Simulation in Impedance-Type Haptic Interfaces

2005 ◽  
Author(s):  
Xiangrong Shen ◽  
Michael Goldfarb
Keyword(s):  
Closed Loop ◽  
Primary Component ◽  
Open Loop ◽  
Haptic Interface ◽  
Haptic Interfaces ◽  
Small Component ◽  
Pneumatic Actuators ◽  
Loop Control ◽  
High Stiffness ◽  
Haptic Simulation

The stable simulation of high-stiffness surfaces remains a challenge in impedance-type haptic simulation of mechanical environments. In this paper, the authors propose an approach to achieving a stable, high-stiffness surface in a haptic interface by leveraging the open-loop properties of pneumatic actuators. By utilizing the open-loop component of actuator stiffness as the primary component of stiffness simulation in a haptic interface, the system requires a comparatively small component of simulated stiffness from closed-loop control of the actuator. A stability analysis is presented indicating that this approach enhances significantly the range of passivity of haptically simulated high-stiffness surfaces. Experimental results both with and without a human operator are presented that demonstrate the effectiveness of the approach.

scholarly journals Simulator of Dynamical Systems and PID Control based on Java Language

2013 ◽  
Vol 9 (S8) ◽  
pp. 59
Author(s):  
Luis Brito Palma ◽  
João Costa Cruz ◽  
Paulo Sousa Gil ◽  
Fernando Vieira Coito
Keyword(s):  
Dynamical Systems ◽  
Pid Control ◽  
Closed Loop ◽  
Time Domain Analysis ◽  
Domain Analysis ◽  
Frequency Domain Analysis ◽  
Open Loop ◽  
Process Models ◽  
Linear Feedback ◽  
Linear Feedback Controller

In this paper, a Java-based simulator of dynamical systems and PID control is presented. This simulator implements linear low-order process models, open-loop architecture and closed-loop architecture with a PID linear feedback controller. The main contribution is a Java application that can be used by the instructor / user in a blended learning environment to teach / learn the basic notions of dynamical systems behavior, some notions of systems stability, perform time domain analysis and frequency domain analysis, and also analyze the effect of PID control in the closed-loop system.

On closed-loop equilibrium strategies for mean-field stochastic linear quadratic problems

2020 ◽  
Vol 26 ◽  
pp. 41
Author(s):  
Tianxiao Wang
Keyword(s):  
Optimal Control ◽  
Closed Loop ◽  
Optimal Control Problems ◽  
Mean Field ◽  
Open Loop ◽  
Time Inconsistency ◽  
Control Problems ◽  
Linear Quadratic ◽  
Linear Quadratic Optimal Control ◽  
Equilibrium Strategies

This article is concerned with linear quadratic optimal control problems of mean-field stochastic differential equations (MF-SDE) with deterministic coefficients. To treat the time inconsistency of the optimal control problems, linear closed-loop equilibrium strategies are introduced and characterized by variational approach. Our developed methodology drops the delicate convergence procedures in Yong [Trans. Amer. Math. Soc. 369 (2017) 5467–5523]. When the MF-SDE reduces to SDE, our Riccati system coincides with the analogue in Yong [Trans. Amer. Math. Soc. 369 (2017) 5467–5523]. However, these two systems are in general different from each other due to the conditional mean-field terms in the MF-SDE. Eventually, the comparisons with pre-committed optimal strategies, open-loop equilibrium strategies are given in details.

Comparison of Dc-Dc SEPIC, CUK and Flyback Converters Based LED Drivers

2020 ◽  
pp. 99-107
Author(s):  
Erdal Sehirli
Keyword(s):  
Integrated Circuit ◽  
Closed Loop ◽  
Input Voltage ◽  
Open Loop ◽  
Current Sensor ◽  
Switching Frequency ◽  
Led Driver ◽  
Advantages And Disadvantages ◽  
Led Drivers ◽  
Conduction Mode

This paper presents the comparison of LED driver topologies that include SEPIC, CUK and FLYBACK DC-DC converters. Both topologies are designed for 8W power and operated in discontinuous conduction mode (DCM) with 88 kHz switching frequency. Furthermore, inductors of SEPIC and CUK converters are wounded as coupled. Applications are realized by using SG3524 integrated circuit for open loop and PIC16F877 microcontroller for closed loop. Besides, ACS712 current sensor used to limit maximum LED current for closed loop applications. Finally, SEPIC, CUK and FLYBACK DC-DC LED drivers are compared with respect to LED current, LED voltage, input voltage and current. Also, advantages and disadvantages of all topologies are concluded.

scholarly journals Parallel Point Clouds: Hybrid Point Cloud Generation and 3D Model Enhancement via Virtual–Real Integration

2021 ◽  
Vol 13 (15) ◽  
pp. 2868
Author(s):  
Yonglin Tian ◽  
Xiao Wang ◽  
Yu Shen ◽  
Zhongzheng Guo ◽  
Zilei Wang ◽  
...  
Keyword(s):  
Point Cloud ◽  
Closed Loop ◽  
Real Data ◽  
Point Clouds ◽  
Autonomous Driving ◽  
Training Model ◽  
Labor Cost ◽  
Open Loop ◽  
Training Dataset ◽  
Data Annotation

Three-dimensional information perception from point clouds is of vital importance for improving the ability of machines to understand the world, especially for autonomous driving and unmanned aerial vehicles. Data annotation for point clouds is one of the most challenging and costly tasks. In this paper, we propose a closed-loop and virtual–real interactive point cloud generation and model-upgrading framework called Parallel Point Clouds (PPCs). To our best knowledge, this is the first time that the training model has been changed from an open-loop to a closed-loop mechanism. The feedback from the evaluation results is used to update the training dataset, benefiting from the flexibility of artificial scenes. Under the framework, a point-based LiDAR simulation model is proposed, which greatly simplifies the scanning operation. Besides, a group-based placing method is put forward to integrate hybrid point clouds, via locating candidate positions for virtual objects in real scenes. Taking advantage of the CAD models and mobile LiDAR devices, two hybrid point cloud datasets, i.e., ShapeKITTI and MobilePointClouds, are built for 3D detection tasks. With almost zero labor cost on data annotation for newly added objects, the models (PointPillars) trained with ShapeKITTI and MobilePointClouds achieved 78.6% and 60.0% of the average precision of the model trained with real data on 3D detection, respectively.

scholarly journals Converting MST to TSP Path by Branch Elimination

2020 ◽  
Vol 11 (1) ◽  
pp. 177
Author(s):  
Pasi Fränti ◽  
Teemu Nenonen ◽  
Mingchuan Yuan
Keyword(s):  
Spanning Tree ◽  
Closed Loop ◽  
Minimum Spanning Tree ◽  
Travelling Salesman Problem ◽  
Open Loop ◽  
Travelling Salesman ◽  
Elimination Algorithm ◽  
Number Of Iterations ◽  
Number Of Branches

Travelling salesman problem (TSP) has been widely studied for the classical closed loop variant but less attention has been paid to the open loop variant. Open loop solution has property of being also a spanning tree, although not necessarily the minimum spanning tree (MST). In this paper, we present a simple branch elimination algorithm that removes the branches from MST by cutting one link and then reconnecting the resulting subtrees via selected leaf nodes. The number of iterations equals to the number of branches (b) in the MST. Typically, b << n where n is the number of nodes. With O-Mopsi and Dots datasets, the algorithm reaches gap of 1.69% and 0.61 %, respectively. The algorithm is suitable especially for educational purposes by showing the connection between MST and TSP, but it can also serve as a quick approximation for more complex metaheuristics whose efficiency relies on quality of the initial solution.

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