scholarly journals Design of bionic active–passive hybrid-driven prosthesis based on gait analysis and simulation of compound control method

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Xinsheng Xu ◽  
Xiaoli Xu ◽  
Ying Liu ◽  
Kai Zhong ◽  
Haowei Zhang
Keyword(s):  
Real Time ◽  
Ankle Joint ◽  
Control Algorithm ◽  
Control Method ◽  
Real Time Control ◽  
Outer Loop ◽  
Time Control ◽  
Human Ankle ◽  
Motion Characteristics ◽  
Joint Prostheses

Abstract Purpose The purpose of this paper is to design a prosthetic limb that is close to the motion characteristics of the normal human ankle joint. Methods In this study, combined with gait experiments, based on a dynamic ankle joint prosthesis, an active–passive hybrid-driven prosthesis was designed. On this basis, a real-time control algorithm based on the feedforward compensation angle outer loop is proposed. To test the effectiveness of the control method, a multi-body dynamic model and a controller model of the prosthesis were established, and a co-simulation study was carried out. Results A real-time control algorithm based on the feedforward compensation angle outer loop can effectively realize the gait angle curve measured in the gait test, and the error is less than the threshold. The co-simulation result and the test result have a high close rate, which reflects the real-time nature of the control algorithm. The use of parallel springs can improve the energy efficiency of the prosthetic system. Conclusions Based on the motion characteristics of human ankle joint prostheses, this research has completed an effective and feasible design of active and passive ankle joint prostheses. The use of control algorithms improves the controllability of the active and passive ankle joint prostheses.

Theory of Temperature Dynamic Control in Arch Dams and its Application

2012 ◽  
Vol 594-597 ◽  
pp. 738-741 ◽  
Author(s):  
Yin Duan ◽  
Xing Hong Liu ◽  
Xiao Lin Chang
Keyword(s):  
Real Time ◽  
Temperature Control ◽  
Control Method ◽  
Dynamic Control ◽  
Arch Dam ◽  
Real Time Control ◽  
New Techniques ◽  
Time Dynamic ◽  
Arch Dams ◽  
Time Control

Main factors of the temperature control and crack prevention in arch dams are summarized. The Space-time Dynamic Control method in pipe cooling process and the Temperature Real-time Control and Decision Database System are introduced to help for temperature real-time control and rapid analysis. Successful application of these new techniques in the construction of Dagangshan arch dam indicates that the proposed method are of significant effectiveness on the temperature control and crack prevention, and have good application prospect in practical project.

Research on 2-Dof Parallel Robot and its Motion Characteristics

2010 ◽  
Vol 139-141 ◽  
pp. 2203-2206
Author(s):  
Hui Ping Shen ◽  
Lei Ding ◽  
Chang Yu Xue ◽  
Ju Li ◽  
Jia Ming Deng ◽  
...  
Keyword(s):  
Real Time ◽  
Industrial Application ◽  
Parallel Mechanism ◽  
Parallel Robot ◽  
Real Time Control ◽  
Time Control ◽  
Surface Welding ◽  
Motion Characteristics ◽  
Straight Lines ◽  
Five Axis

A novel robot, derived from a planar parallel mechanism, is presented. With two sliders driving on the same side of parallel guide rails, this simple but practical mechanism is capable of realizing a large workspace. The direct and inverse kinematical solutions are given. The simulation demonstrates that all kinds of straight lines and circles can be realized by the end actuator of the robot; the corresponding motion disciplines and characteristics driven by the two sliders are analyzed; the results are verified on the prototype. By allowing the end actuator to move in Z-direction or to rotate around A or B-axis, three-, four-, five-axis manipulator would be composed and surface welding and space cutting would be realized. This paper lays the foundation for the real-time control and industrial application of this novel robot.

Joint Self-Tuning With Cartesian Setpoints

1986 ◽  
Vol 108 (2) ◽  
pp. 146-150 ◽  
Author(s):  
P. G. Backes ◽  
G. G. Leininger ◽  
Chun-Hsien Chung
Keyword(s):  
Real Time ◽  
Control Method ◽  
Hybrid Control ◽  
Pole Placement ◽  
Real Time Control ◽  
Time Control ◽  
Self Tuning ◽  
Cause Of Error ◽  
Time Position ◽  
Manipulator Control

A joint coordinate self-tuning manipulator control method is presented which uses Cartesian setpoints. The method is capable of both position and hybrid control. Position and force errors are transformed from Cartesian coordinates to position and force errors at the joints. The position and force errors at each joint are combined into one hybrid error that is eliminated using pole-placement self-tuning. Real time position and hybrid control results are given. No prior knowledge of manipulator or load dynamics is required and real time control results show that the goal of consistent control with changing load dynamics is achieved. The major cause of error in position and hybrid control is the large friction effects in the joints.

An application of real-time control systems to robotics

Robotica ◽  
2001 ◽  
Vol 19 (3) ◽  
pp. 323-329 ◽  
Author(s):  
Carmen Monroy ◽  
Ricardo Campa ◽  
Rafael Kelly
Keyword(s):  
Control Systems ◽  
Real Time ◽  
Control Algorithm ◽  
Computing Environment ◽  
Real Time Control ◽  
Time Control ◽  
On Line ◽  
Robot Performance ◽  
Single Processor ◽  
Selection Of

This paper illustrates basic concepts of real-time control systems through the application of a real-time single-processor computing environment for the control of a robotic arm. The paper describes elements for the selection of the real-time architecture, the control algorithm and the graphical user interface. The system provides an opportunity for users to verify the robot performance by changing on-line the controller parameters and the shape of the desired motion.

scholarly journals Optimisation of a fuzzy logic-based local real-time control system for mitigation of sewer flooding using genetic algorithms

2019 ◽  
Vol 22 (2) ◽  
pp. 281-295 ◽  
Author(s):  
S. R. Mounce ◽  
W. Shepherd ◽  
S. Ostojin ◽  
M. Abdel-Aal ◽  
A. N. A. Schellart ◽  
...  
Keyword(s):  
Fuzzy Logic ◽  
Real Time ◽  
Control Algorithm ◽  
Expert Knowledge ◽  
Economic Losses ◽  
Rainfall Time Series ◽  
Real Time Control ◽  
Spare Capacity ◽  
Time Control ◽  
Drainage Networks

Abstract Urban flooding damages properties, causes economic losses and can seriously threaten public health. An innovative, fuzzy logic (FL)-based, local autonomous real-time control (RTC) approach for mitigating this hazard utilising the existing spare capacity in urban drainage networks has been developed. The default parameters for the control algorithm, which uses water level-based data, were derived based on domain expert knowledge and optimised by linking the control algorithm programmatically to a hydrodynamic sewer network model. This paper describes a novel genetic algorithm (GA) optimisation of the FL membership functions (MFs) for the developed control algorithm. In order to provide the GA with strong training and test scenarios, the compiled rainfall time series based on recorded rainfall and incorporating multiple events were used in the optimisation. Both decimal and integer GA optimisations were carried out. The integer optimisation was shown to perform better on unseen events than the decimal version with considerably reduced computational run time. The optimised FL MFs result in an average 25% decrease in the flood volume compared to those selected by experts for unseen rainfall events. This distributed, autonomous control using GA optimisation offers significant benefits over traditional RTC approaches for flood risk management.

Control Design for Automated Vehicle Emergency Safe Stop System Based on Differential Dynamic Programming

2020 ◽  
Author(s):  
Lisheng Yang ◽  
Tomonari Furukawa ◽  
Lei Zuo ◽  
Zachary Doerzaph
Keyword(s):  
Dynamic Programming ◽  
Real Time ◽  
Control Algorithm ◽  
Computation Time ◽  
Grid Cell ◽  
System Control ◽  
Real Time Control ◽  
Differential Dynamic Programming ◽  
Time Control ◽  
Emergency Stop

Abstract This paper presents the control algorithm and system design for a newly proposed automated emergency stop system, which aims to navigate the vehicle out of its travel lane to a safe road-side location when an emergency (e.g. driver fails to take control during fallback of the Dynamic Driving Task) occurs. To address the unique requirements of such a system, control techniques based on differential dynamic programming are developed. Optimal control sequence computation is broken down into step-by-step quadratic optimization and solved iteratively. Control constraints are addressed efficiently by a tailored Projected-Newton algorithm. The iterative control algorithm is then integrated into a real-time control system which considers both computation delay and modeling errors. The system employs a novel grid-based storage structure for recording all acceptable control commands computed within the iteration and uses a high frequency estimator for self-localization. During operation, the real-time control thread will extract commands from the grid cell corresponding to current states. Simulation results show strong potential of the proposed system for addressing the engineering challenges of the automated emergency stop function. The robustness of the system in presence of computation time delay and modelling errors is also demonstrated.

SPC-Based Real-Time Control Method for CNC Machining Quality

2010 ◽  
Vol 42 ◽  
pp. 263-267
Author(s):  
Xin Long Kang ◽  
Dong Man Yu ◽  
Xue Ling Yang ◽  
Di Wang
Keyword(s):  
Real Time ◽  
High Precision ◽  
Control Method ◽  
Cnc Machining ◽  
Machining Process ◽  
Real Time Control ◽  
The Real ◽  
Machining Quality ◽  
Time Control ◽  
Process System

This paper presents the methods and applications for the real-time control of CNC machining process quality in detail and clarifies the objectives of SPC for CNC machining, in order to enhance the understanding of the factors that cause instability to process system. Also, this paper adopts the methods and procedures for SPC to effectively serve the production of high-precision products for enterprises, in order to meet customers’ requirements and expectations.

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