Gait Emulator for Evaluation of a Powered Ankle-Foot Prosthesis

2017 ◽  
Author(s):  
Evandro Ficanha ◽  
Houman Dallali ◽  
Mo Rastgaar
Keyword(s):  
Control System ◽  
Degrees Of Freedom ◽  
Closed Loop ◽  
Hybrid Control ◽  
Design Parameters ◽  
Parameter Uncertainties ◽  
Walking Tests ◽  
Walking Speeds ◽  
Hybrid Control System ◽  
Smooth System

In this paper we present an enhanced gait emulator and a novel hybrid control system to test powered ankle-foot prostheses with two degrees of freedom in the sagittal and frontal planes. The gait emulator is a nonlinear and non-smooth system that has to follow a precisely timed set of phases to achieve a human-like periodic gait. Despite the complexity and parameter uncertainties of this five degrees of freedom system, our proposed hybrid control system simplifies the walking control by use of state triggered kinematic events. The control system works in closed loop with kinematic event detection to ensure robust and repeatable walking tests as design parameters are varied. The developed gait emulator can be used to test the prosthesis under various loading conditions and walking speeds.

Improved hand prostheses control for transradial amputees based on hybrid of voice recognition and electromyography

2020 ◽  
pp. 039139882097665
Author(s):  
Omer Saad Alkhafaf ◽  
Mousa K Wali ◽  
Ali H Al-Timemy
Keyword(s):  
Control System ◽  
Degrees Of Freedom ◽  
Grip Force ◽  
Hybrid Control ◽  
Combination Strategy ◽  
Emg Control ◽  
Upper Limb Prostheses ◽  
Reasonable Cost ◽  
Hybrid Control System ◽  
The Voice

The control of prostheses and their complexities is one of the greatest challenges limiting wide amputees’ use of upper limb prostheses. The main challenges include the difficulty of extracting signals for controlling the prostheses, limited number of degrees of freedom (DoF), and cost-prohibitive for complex controlling systems. In this study, a real-time hybrid control system, based on electromyography (EMG) and voice commands (VC) is designed to render the prosthesis more dexterous with the ability to accomplish amputee’s daily activities proficiently. The voice and EMG systems were combined in three proposed hybrid strategies, each strategy had different number of movements depending on the combination protocol between voice and EMG control systems. Furthermore, the designed control system might serve a large number of amputees with different amputation levels, and since it has a reasonable cost and be easy to use. The performance of the proposed control system, based on hybrid strategies, was tested by intact-limbed and amputee participants for controlling the HANDi hand. The results showed that the proposed hybrid control system was robust, feasible, with an accuracy of 94%, 98%, and 99% for Strategies 1, 2, and 3, respectively. It was possible to specify the grip force applied to the prosthetic hand within three gripping forces. The amputees participated in this study preferred combination Strategy 3 where the voice and EMG are working concurrently, with an accuracy of 99%.

Active Vibration Control for Base-Isolated Structures Using a PID Controller against Earthquakes

2016 ◽  
Vol 26 ◽  
pp. 99-110 ◽  
Author(s):  
Nassim Djedoui ◽  
Abdelhafid Ounis ◽  
Mahdi Abdeddaim
Keyword(s):  
Control System ◽  
Pid Controller ◽  
Closed Loop ◽  
Hybrid Control ◽  
Tuned Mass Damper ◽  
Frame Structure ◽  
Control Force ◽  
Mass Damper ◽  
Base Displacement ◽  
Hybrid Control System

In this paper, a closed loop control approach for controlling the vibration of buildings under earthquake excitations is introduced. An active hybrid control combining base isolation and active tuned mass damper (AMD) installed on the lowest floor of a base-isolated frame building is investigated. The Active control force is controlled by the mean of a proportional–integral–derivative (PID) controller, incorporated with a negative feedback error closed loop. The difference between the base displacement and equilibrium position of the structure is used to evaluate the error and feed the PID controller. A simulation is carried out on a six degrees of freedom base-isolated frame structure using MATLAB. The performances of the proposed active hybrid control system are tested under El Centro, Northridge, and Loma Pietra earthquakes.Compared results with base-isolated structure and base-isolated structure equipped with a passive and active tuned mass damper (TMD)/ (ATMD) showed that the active hybrid control system is more efficient. A reduction of 70% in base displacement, velocity and 15% in base acceleration is obtained.

Research on hybrid control system of quadrotor UAV

2013 ◽  
Vol 33 (3) ◽  
pp. 858-861 ◽  
Author(s):  
Guoqing XIA ◽  
Yuefeng LIAO ◽  
Lu WANG
Keyword(s):  
Control System ◽  
Hybrid Control ◽  
Quadrotor Uav ◽  
Hybrid Control System

CMAC Based Hybrid Control System for Solving Electrohydraulic System Nonlinearities

2014 ◽  
Vol 4 (2) ◽  
pp. 47-72
Author(s):  
Amro Shafik ◽  
Magdy Abdelhameed ◽  
Ahmed Kassem
Keyword(s):  
Neural Network ◽  
Control System ◽  
Hybrid Control ◽  
Learning Algorithm ◽  
Cerebellar Model Articulation Controller ◽  
Stick Slip ◽  
Electrohydraulic System ◽  
Cmac Neural Network ◽  
Wide Range ◽  
Hybrid Control System

Automation based electrohydraulic servo systems have a wide range of applications in nowadays industry. However, they still suffer from several nonlinearities like deadband in electrohydraulic valves, hysteresis, stick-slip friction in valves and cylinders. In addition, all hydraulic system parameters have uncertainties in their values due to the change of temperature while working. This paper addresses these problems by designing a suitable intelligent control system that has the ability to deal with the system nonlinearities and parameters uncertainties using a fast and online learning algorithm. A novel hybrid control system based on Cerebellar Model Articulation Controller (CMAC) neural network is presented. The proposed controller is composed of two parallel controllers. The first is a conventional Proportional-Velocity (PV) servo type controller which is used to decrease the large initial error of the closed-loop system. The second is a CMAC neural network which is used as an intelligent controller to overcome nonlinear characteristics of the electrohydraulic system. A fourth order model for the electrohydraulic system is introduced. PV controller parameters are tuned to get optimal values. Simulation and experimental results show a good tracking performance obtained using the proposed controller. The controller shows its robustness in two working environments. The first is by adding different inertia loads and the second is working with noisy level input signals.

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