Adaptive Tracking Control of an Air Powered Robot Actuator

1993 ◽  
Vol 115 (3) ◽  
pp. 427-433 ◽  
Author(s):  
B. W. McDonell ◽  
J. E. Bobrow
Keyword(s):  
Tracking Control ◽  
Position Control ◽  
Adaptive Controller ◽  
Pneumatic Actuator ◽  
Tracking Accuracy ◽  
Nonlinear Characteristics ◽  
Adaptive Tracking Control ◽  
Full State ◽  
Full State Feedback ◽  
High Bandwidth

An adaptive controller is presented for a one-degree-of-freedom pneumatic actuator. The control law uses full-state feedback for simultaneous parameter identification and tracking control. For position control, a pneumatic actuator with high bandwidth is difficult to obtain because of the compressibility of air and the nonlinear characteristics of air flowing through a variable area orifice. Most previous controllers for gas powered actuators were relatively limited fixed gain or on-off type controllers with low tracking accuracy. Experimental results demonstrate that tracking performance comparable to electric servomotors can be obtained using the algorithm presented despite the nonlinearities and compressibility of air.

Adaptive, High Bandwidth Control of a Hydraulic Actuator

1996 ◽  
Vol 118 (4) ◽  
pp. 714-720 ◽  
Author(s):  
J. E. Bobrow ◽  
K. Lum
Keyword(s):  
Adaptive Controller ◽  
Hydraulic Actuator ◽  
Controlled Systems ◽  
Full State ◽  
Parameter Variations ◽  
Full State Feedback ◽  
Bandwidth Control ◽  
High Bandwidth ◽  
On Line ◽  
Proportional Controller

Hydraulic servovalve controlled systems contain many time-varying dynamic characteristics that are difficult to model Controllers for such systems must either adapt to these changing parameters or be robust enough to handle the parameter variations. In order to achieve the highest possible bandwidth, an adaptive controller is developed for the system that uses full-state feedback for simultaneous parameter identification and tracking control This controller takes into account the hydraulic fluid compressibility with an on-line identification scheme Experimental results demonstrate a four fold improvement in bandwidth as compared to a conventional fixed gain proportional controller.

Adaptive Pneumatic Force Actuation and Position Control

1991 ◽  
Vol 113 (2) ◽  
pp. 267-272 ◽  
Author(s):  
J. E. Bobrow ◽  
F. Jabbari
Keyword(s):  
Position Control ◽  
Low Cost ◽  
Equations Of Motion ◽  
Pneumatic Actuator ◽  
Unit Weight ◽  
Force Output ◽  
Nonlinear Characteristics ◽  
Pneumatic Actuators ◽  
Highly Nonlinear ◽  
High Bandwidth

In this paper an implementation of an adaptive control law for a pneumatic actuator is presented. Pneumatic actuators are of particular interest for robotic applications because of their large force output per unit weight, and their low cost. Stabilization of a pneumatic actuator is difficult if a high bandwidth closed-loop system is desired. This is because of the compressibility of air, and of the nonlinear characteristics of air flowing through a variable area orifice. Further complications arise from the geometry of the mechanism because the equations of motion are highly nonlinear. The order of the dominant dynamics is shown to vary with the position of the mechanicsm.

Flexible-Joint Humanoid Balancing Augmentation via Full-State Feedback Variable Impedance Control

2021 ◽  
Vol 13 (2) ◽  
Author(s):  
Emmanouil Spyrakos-Papastavridis ◽  
Jian S. Dai
Keyword(s):  
State Feedback ◽  
Position Control ◽  
Impedance Control ◽  
Humanoid Robots ◽  
Flexible Joint ◽  
Model Free ◽  
Floating Base ◽  
Full State ◽  
Full State Feedback ◽  
Series Elastic Actuators

Abstract This paper attempts to address the quandary of flexible-joint humanoid balancing performance augmentation, via the introduction of the Full-State Feedback Variable Impedance Control (FSFVIC), and Model-Free Compliant Floating-base VIC (MCFVIC) schemes. In comparison to rigid-joint humanoid robots, efficient balancing control of compliant bipeds, powered by Series Elastic Actuators (or harmonic drives), requires the design of more sophisticated controllers encapsulating both the motor and underactuated link dynamics. It has been demonstrated that Variable Impedance Control (VIC) can improve robotic interaction performance, albeit by introducing energy-injecting elements that may jeopardize closed-loop stability. To this end, the novel FSFVIC and MCFVIC schemes are proposed, which amalgamate both collocated and non-collocated feedback gains, with power-shaping signals that are capable of preserving the system's stability/passivity during VIC. The FSFVIC and MCFVIC stably modulate the system's collocated state gains to augment balancing performance, in addition to the non-collocated state gains that dictate the position control accuracy. Utilization of arbitrarily low-impedance gains is permitted by both the FSFVIC and MCFVIC schemes propounded herein. An array of experiments involving the COmpliant huMANoid reveals that significant balancing performance amelioration is achievable through online modulation of the full-state feedback gains (VIC), as compared to utilization of invariant impedance control.

Adaptive Backstepping Control of the Gripping Process of Heavy Manipulators

2017 ◽  
Author(s):  
Lixin Yang ◽  
Xianmin Zhang
Keyword(s):  
Tracking Control ◽  
Hydraulic Drive ◽  
Adaptive Controller ◽  
Drive System ◽  
Uncertain Parameters ◽  
Backstepping Method ◽  
Nonlinear Characteristics ◽  
Cylinder Model ◽  
Stability Principle ◽  
The Stability

A valve-controlled asymmetrical cylinder model was established to study the gripping hydraulic drive system of the grip device of heavy manipulator. Due to the strong nonlinear characteristics and uncertain parameters of the model, the Lyapunov stability principle was used to design a multistage inversion adaptive controller based on backstepping method and by introducing the virtual control parameter. The simulation results reveal that the tracking control and adaptive of uncertain parameters are very effective, which confirm that the designed controller can guarantee the stability of the closed-loop clamping hydraulic drive system.

Adaptive Tracking Control of Industrial Robots

1988 ◽  
Vol 110 (3) ◽  
pp. 215-220 ◽  
Author(s):  
G. Ambrosino ◽  
G. Celentano ◽  
F. Garofalo
Keyword(s):  
Input Signal ◽  
Tracking Control ◽  
Design Procedure ◽  
Adaptive Controller ◽  
Approximate Model ◽  
Industrial Robots ◽  
Uncertain Parameters ◽  
Load Variations ◽  
Adaptive Tracking Control ◽  
Control Scheme

A design procedure for the synthesis of an adaptive controller for a robotic manipulator is presented. The design involves the evaluation of a nominal input signal by using a model of the manipulator with nominal values of the loads, and of an adaptive component by means of the sole knowledge of the maximum possible size of the uncertain parameters of the model. The proposed control scheme also guarantees an accurate tracking of a planned path when an approximate model of the manipulator is used and/or load variations occur during operation. Moreover, the resulting control signal is smooth.

scholarly journals Direct Adaptive Tracking Control for a Class of Pure-Feedback Stochastic Nonlinear Systems Based on Fuzzy-Approximation

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Huanqing Wang ◽  
Xiaoping Liu ◽  
Qi Zhou ◽  
Hamid Reza Karimi
Keyword(s):  
Nonlinear Systems ◽  
Tracking Control ◽  
Controller Design ◽  
Tracking Error ◽  
Small Neighborhood ◽  
Adaptive Controller ◽  
Stochastic Nonlinear Systems ◽  
Fuzzy Logic Systems ◽  
Adaptive Tracking Control ◽  
Adaptive Tracking

The problem of fuzzy-based direct adaptive tracking control is considered for a class of pure-feedback stochastic nonlinear systems. During the controller design, fuzzy logic systems are used to approximate the packaged unknown nonlinearities, and then a novel direct adaptive controller is constructed via backstepping technique. It is shown that the proposed controller guarantees that all the signals in the closed-loop system are bounded in probability and the tracking error eventually converges to a small neighborhood around the origin in the sense of mean quartic value. The main advantages lie in that the proposed controller structure is simpler and only one adaptive parameter needs to be updated online. Simulation results are used to illustrate the effectiveness of the proposed approach.

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