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Proportional control

About: Proportional control is a research topic. Over the lifetime, 3756 publications have been published within this topic receiving 49050 citations.


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Journal ArticleDOI
TL;DR: This is the first simultaneous proportional myoelectric control system demonstrated on a prosthesis affixed to the forearm of a subject and illustrates that PGT is a promising system training method for proportional control.
Abstract: Pattern recognition control of prosthetic hands take inputs from one or more myoelectric sensors and controls one or more degrees of freedom. However, most systems created allow only sequential control of one motion class at a time. Additionally, only recently have researchers demonstrated proportional myoelectric control in such systems, an option that is believed to make fine control easier for the user. Recent developments suggest improved reliability if the user follows a so-called prosthesis guided training (PGT) scheme. In this study, a system for simultaneous proportional myoelectric control has been developed for a hand prosthesis with two motor functions (hand open/close, and wrist pro-/supination). The prosthesis has been used with a prosthesis socket equivalent designed for normally-limbed subjects. An extended version of PGT was developed for use with proportional control. The control system’s performance was tested for two subjects in the Clothespin Relocation Task and the Southampton Hand Assessment Procedure (SHAP). Simultaneous proportional control was compared with three other control strategies implemented on the same prosthesis: mutex proportional control (the same system but with simultaneous control disabled), mutex on-off control, and a more traditional, sequential proportional control system with co-contractions for state switching. The practical tests indicate that the simultaneous proportional control strategy and the two mutex-based pattern recognition strategies performed equally well, and superiorly to the more traditional sequential strategy according to the chosen outcome measures. This is the first simultaneous proportional myoelectric control system demonstrated on a prosthesis affixed to the forearm of a subject. The study illustrates that PGT is a promising system training method for proportional control. Due to the limited number of subjects in this study, no definite conclusions can be drawn.

66 citations

Journal ArticleDOI
TL;DR: In this paper, a control system for a tubular synchronous linear motor based on a sliding-mode control and a proportional-integral (PI)-based equivalent disturbance observer is described.
Abstract: Direct drives with linear motors have been recently attracting the attention of both industry and academia. The main peculiarity of these systems is the lack of mechanical reduction and transmission devices, which makes the influence of some uncertain electromechanical phenomena (e.g., friction, cogging forces, etc.) and load disturbances much more significant than in the case of conventional rotary actuators. This paper describes a control system for a tubular synchronous linear motor based on a sliding-mode control (SMC) and a proportional-integral (PI)-based equivalent disturbance observer. The distinctive peculiarities of the proposed scheme are the use of a control law that guarantees the stability of the system regardless of the payload mass, the adoption of a double boundary layer addressing effectively the harmful effects of static friction, and the introduction of a simple PI-based equivalent disturbance observer that avoids steady-state errors regardless of model uncertainties and external disturbances. The reduced computational cost of the control law, alongside with the introduction of the effective design criteria for the SMC and the disturbance observer, makes the implementation of the proposed approach as simple as standard cascaded linear control schemes using industrial microcontrollers. The aforementioned considerations are validated by extensive experiments.

66 citations

Journal ArticleDOI
01 Feb 1978
TL;DR: Some recent research results on algorithms designed for use in stand-alone, single-loop calculator or microprocessor-based controllers are presented, specifically tailored for simple implementation in a relatively low computing power, discrete-time environment.
Abstract: Process control applications and control algorithms suited for microprocessors are surveyed. Applications are noted both in large, general purpose process control systems and in specialized applications that have been made possible by the availability of computing power in small packages. Distributed control and use of extended data buses (data highways), both made possible by extensive use of microprocessors, are becoming standard in general purpose systems. General purpose process control systems still utilize proportional-integral-derivative (PID) algorithms and variants of them for the most part. Some recent research results on algorithms designed for use in stand-alone, single-loop calculator or microprocessor-based controllers are presented. These algorithms, which could also be used in direct digital control (DDC) systems, are specifically tailored for simple implementation in a relatively low computing power, discrete-time environment.

66 citations

Proceedings ArticleDOI
01 Apr 2007
TL;DR: It is concluded that the fuzzy controller performance outperformed the PID controller; moreover, the tuning process using the STA method was easier than using the Ziegler-Nichols method.
Abstract: We are presenting the usefulness of an innovative method called simple tuning algorithm (STA) for tuning fuzzy controllers, it has only one variable to adjust to achieve the tuning goal, this in counterpart to other methods like the proportional integral derivative (PID) controller wish has three variables to adjust for the same goal. Comparative examples of the STA and the PID methods are presented in a speed control of a real DC gear motor application. The PID controller was tuned using the Ziegler-Nichols. In base of the obtained quantitative and qualitative measures and observations, we are concluding that the fuzzy controller performance outperformed the PID controller; moreover, the tuning process using the STA method was easier than using the Ziegler-Nichols method

66 citations

Journal ArticleDOI
TL;DR: In this paper, a dual-level control is proposed to solve the problem of ignorable coordinates, where the first level control is designed to control the first-level coordinates and lead to a positive definite "augmented system" and the second-level controls are designed for the final control of the complete state vector, including the ignorable coordinate.
Abstract: One problem peculiar to spacecraft in free space is that of ignorable coordinates, which are present when the spacecraft has no natural ability of preventing rigid-body motions. Ignorable coordinates can be eliminated from the problem formulation by introducing a reduced state vector. However, this results in having the ignorable coordinates uncontrolled. This paper solves this problem by introducing a dual-level control. The firstlevel controls are designed to control the ignorable coordinates and they lead to a positive definite "augmented system" and the second-level controls are designed for the final control of the complete state vector, including the ignorable coordinates. The second-level controls are designed in modal space and can be based on several types of control laws. In particular, proportional control providing artificial viscous damping, proportional optimal control, and nonlinear on-off control are discussed. A numerical example, illustrating all of these control laws, is presented.

66 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20237
202217
202162
2020110
2019150
2018150