Control of Exoskeletons Inspired by Fictitious Variable Gain in Human

2008 ◽  
Author(s):  
Kyoungchul Kong ◽  
Masayoshi Tomizuka
Keyword(s):  
Control System ◽  
Control Algorithm ◽  
Controller Design ◽  
Assistive Device ◽  
Single Input Single Output ◽  
Variable Gain ◽  
Single Output ◽  
Single Input ◽  
Parallel Control ◽  
The Brain

A human wearing an exoskeleton-type assistive device results in a parallel control system that includes two controllers: the human brain and a digital exoskeleton controller. Unknown and complicated characteristics of the brain dynamically interact with the exoskeleton controller which makes the controller design challenging. In this paper, the motion control system of a human is regarded as a feedback control loop that consists of a brain, muscles and the dynamics of the extended human body. The brain is modeled as a control algorithm amplified by a fictitious variable gain. The variable gain compensates for characteristic changes in the muscle and dynamics. If a human is physically impaired or subjected to demanding work, the exoskeleton should generate proper assistive forces, which is equivalent to increasing the variable gain. In this paper, a control algorithm that realizes the fictitious variable gain is designed and its performance and robustness are discussed for single-input single-output cases. The control algorithm is then verified by simulation results.

scholarly journals Comparative study of zero effects in pole-placement control system design via the shift and delta transforms

2005 ◽  
Vol 18 (3) ◽  
pp. 439-451
Author(s):  
Milica Naumovic
Keyword(s):  
Control System ◽  
System Design ◽  
Pole Placement ◽  
Control System Design ◽  
Single Input Single Output ◽  
Single Output ◽  
Continuous Time Systems ◽  
Single Input ◽  
Pole Placement Control ◽  
Time Systems

This paper deals with the special replacement of the shift operator and its associated z transform by delta operator and ? transform, respectively. The aim of the paper is to clarify the role of zeros of discretized linear single input single output continuous-time systems modeled by shift and delta operators. In particular, the effect of zero dynamics on the control system design based on classical pole-zero assignment in the case of both operators is considered. The analysis is illustrated by simulation results.

Isotropic Compliance in E(3): Feasibility and Workspace Mapping

2016 ◽  
Vol 8 (6) ◽  
Author(s):  
Matteo Verotti ◽  
Nicola P. Belfiore
Keyword(s):  
Control System ◽  
Euclidean Space ◽  
Joint Control ◽  
Control Law ◽  
Single Input Single Output ◽  
Gain Ratio ◽  
Single Output ◽  
Control Gain ◽  
Single Input ◽  
Manipulator Control

A manipulator control system, for which isotropic compliance holds in the Euclidean space E(3), can be significantly simplified by means of diagonal decoupling. However, such simplification may introduce some limits to the region of the workspace where the sought property can be achieved. The present investigation reveals how to detect which peculiar subset, among four different classes, a given manipulator belongs to. The paper also introduces the concept of control gain ratio for each specific single-input/single-output joint control law in order to limit the maximum gain required to achieve the isotropic compliance condition.

scholarly journals MIMO Passive Control Systems Are Not Necessarily Robust

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Jesús U. Liceaga-Castro ◽  
Irma I. Siller-Alcalá ◽  
Eduardo Liceaga-Castro ◽  
Luis A. Amézquita-Brooks
Keyword(s):  
Control System ◽  
Structure Function ◽  
Control Systems ◽  
Passive Control ◽  
Linear Control System ◽  
Linear Control ◽  
Single Input Single Output ◽  
Single Output ◽  
Single Input

Via several cases of study it is shown that a passive multivariable linear control system, contrary to its single input single output counterpart, may not be robust. Moreover, it is shown that lack of robustness can be exposed via the multivariable structure function.

Double-Input Multi-Output Pressure Control System Based on Addressable Pressure Component

2021 ◽  
Author(s):  
Qiandiao Wei ◽  
He Xu ◽  
Siqing Chen ◽  
Weiwang Fan
Keyword(s):  
Control System ◽  
Control Method ◽  
Pressure Control ◽  
Supply Source ◽  
Single Input Single Output ◽  
Square Wave ◽  
Output Pressure ◽  
Single Output ◽  
Pressure Control System ◽  
Single Input

Abstract Soft robots driven by pressurized fluid have recently been attracted more attention and achieved a variety of innovative applications in bionics, medical surgery, rehabilitation, search, and rescue system. And they have been demonstrated to be able to perform many different tasks, especially in some conditions of demand a high degree of compliance. Generally, they consisted of multiple actuate channels that require independent works. Consequently, a mass of pressure regulators and input pipelines are demanded, which will increase the complexity of the control system. To solve this problem, we propose a new pressure control method inspired by the control bus of electronic interface technology in this paper. An addressable pressure control bus system based on band-pass valve (BPV) and square wave of pressure (control signal) was designed. It consisted of a pressure supply source and an addressing signal, they are controled by two regulators, respectively. One of the pressure pipelines serves as the control bus to transmit the control pressure signal, which plays an addressing signal role in the system. The other serves as the pressure supply source of the multi-channel actuators. The BPV can be set to different opening pressure bands to realize the setting of diverse outputs address codes on the bus. This method discovered the work mode of double-input multi-output, which will get rids of the traditional control method of single-input single-output. In this paper, we designed the BPV and tested its function. To demonstrate the feasibility of this method proposed, a control system with two output ports was established. The result has shown that the output port can be selected by the pressure square wave signal, which realizes the function of single input multiple outputs. It reduces the complexity of the control strategy of the fluid control system.

Single-input—single-output control system synthesis

1985 ◽  
Vol 9 (6) ◽  
pp. 557-566 ◽  
Author(s):  
R.D. Johnson ◽  
G.W. Barton ◽  
M.L. Brisk
Keyword(s):  
Control System ◽  
Output Control ◽  
System Synthesis ◽  
Single Input Single Output ◽  
Single Output ◽  
Single Input ◽  
Control System Synthesis

Hover Position of Quadrotor Based on PD-like Fuzzy Linear Programming

2016 ◽  
Vol 6 (5) ◽  
pp. 2251
Author(s):  
Iswanto Iswanto ◽  
Oyas Wahyunggoro ◽  
Adha Imam Cahyadi
Keyword(s):  
Linear Programming ◽  
Pid Control ◽  
Control Algorithm ◽  
Fuzzy Linear Programming ◽  
Single Input Single Output ◽  
Pid Algorithm ◽  
Single Output ◽  
Single Input ◽  
Control Modification ◽  
Altitude Control

<p>The purpose of this paper is to present the altitude control algorithm for quadrotor to be able to fly at a particular altitude. Several previous researchers have conducted studies on quadrotor altitude by using PID control but there are problems in the overshoot and oscillation. To optimize the control, tunning on PID algorithm must be first conducted to determine proportional and derivative constants. Hence, the paper presents altitude control modification by using PID-like fuzzy without tuning. The PID algorithm is a control algorithm for linear systems. While, system to be controlled is a non-linear, so that linearization is needed by using equilibrium. The proposed algorithm is a modification of the PID algorithm used as an altitude control which enables quadrotor to be stable when hovering. The algorithm used is not PID algorithm with tuning using fuzzy, but this is a single input single output (SISO) control PID-like fuzzy linear programming. The result of the research shows that quadrotor can hover in a rapid raise time, steady state and settling time without performing overshoot and oscillation.</p>

Indirect Adaptive Fuzzy H∞ Tracking Control with Self-Structuring Algorithm for a Class of Uncertain Nonlinear SISO Systems

2013 ◽  
Vol 756-759 ◽  
pp. 622-626
Author(s):  
Sen Xu ◽  
Zhang Quan Wang ◽  
You Rong Chen ◽  
Ban Teng Liu ◽  
Lu Yao Xu
Keyword(s):  
Fuzzy Controller ◽  
Controller Design ◽  
Pendulum System ◽  
Single Input Single Output ◽  
Adaptive Fuzzy ◽  
Single Output ◽  
Inverted Pendulum System ◽  
Single Input ◽  
Indirect Adaptive Fuzzy Controller ◽  
Siso Systems

Indirect adaptive fuzzy controller with a self-structuring algorithm is proposed in this paper to achieve tracking performance for a class of uncertain nonlinear single-input single-output (SISO) systems with external disturbances. Selecting membership functions and the fuzzy rules are difficult in fuzzy controller design. As a result, self-structuring algorithm is used in this paper, which simplifies the design of fuzzy controller. Lyapunov analysis is used to prove asymptotic stability of the proposed approach. Application of the proposed control scheme to a second-order inverted pendulum system demonstrates the effectiveness of the proposed approach.

scholarly journals Modified approach to distillation column control

2017 ◽  
Vol 71 (3) ◽  
pp. 183-193
Author(s):  
Sasa Prodanovic ◽  
Novak Nedic ◽  
Vojislav Filipovic ◽  
Ljubisa Dubonjic
Keyword(s):  
Distillation Column ◽  
Controller Design ◽  
Industrial Plant ◽  
Control Analysis ◽  
Centralized Control ◽  
Single Input Single Output ◽  
Response Characteristics ◽  
Single Output ◽  
Single Input ◽  
Integral Error

This paper contains methodology research for forming the control algorithm for a distillation column, modeled as TITO (two-input two-output) process. Its modified form was obtained by connecting the two parts, and this combination hasn't been applied for such a industrial plant, until now. These parts include: a simplified decoupler which was first designed and decentralized PID controller obtained using D-decomposition method for such decoupled process. The decoupler was designed in order to make process become diagonal, and parameters of PID controllers are defined for the two SISO (single-input single-output) processes starting from relation between IE (integral error) criterion and integrator gain, taking into account desired response characteristics deriving from technological requirements of controlled plant. Their connecting provides centralized control. Analysis of the processes responses, obtained by the proposed algorithm and their comparison with the results from the literature, were performed after the completion of the simulations. The proposed approach to the centralized controller design, beside its simplicity of usage and flexibility in achieving diversity of process dynamic behavior, gives better response characteristics, in comparison with existing control algorithms for distillation column in the literature.

scholarly journals Hover Position of Quadrotor Based on PD-like Fuzzy Linear Programming

2016 ◽  
Vol 6 (5) ◽  
pp. 2251
Author(s):  
Iswanto Iswanto ◽  
Oyas Wahyunggoro ◽  
Adha Imam Cahyadi
Keyword(s):  
Linear Programming ◽  
Pid Control ◽  
Control Algorithm ◽  
Fuzzy Linear Programming ◽  
Single Input Single Output ◽  
Pid Algorithm ◽  
Single Output ◽  
Single Input ◽  
Control Modification ◽  
Altitude Control

<p>The purpose of this paper is to present the altitude control algorithm for quadrotor to be able to fly at a particular altitude. Several previous researchers have conducted studies on quadrotor altitude by using PID control but there are problems in the overshoot and oscillation. To optimize the control, tunning on PID algorithm must be first conducted to determine proportional and derivative constants. Hence, the paper presents altitude control modification by using PID-like fuzzy without tuning. The PID algorithm is a control algorithm for linear systems. While, system to be controlled is a non-linear, so that linearization is needed by using equilibrium. The proposed algorithm is a modification of the PID algorithm used as an altitude control which enables quadrotor to be stable when hovering. The algorithm used is not PID algorithm with tuning using fuzzy, but this is a single input single output (SISO) control PID-like fuzzy linear programming. The result of the research shows that quadrotor can hover in a rapid raise time, steady state and settling time without performing overshoot and oscillation.</p>

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