Design and Testing of a Servo Controller for Pneumatic Cylinders

1989 ◽  
Vol 203 (1) ◽  
pp. 21-27 ◽  
Author(s):  
J A Marchant ◽  
M J Street ◽  
P Gurney ◽  
J A Benson
Keyword(s):  
Closed Loop ◽  
Experimental System ◽  
External Source ◽  
Pole Placement ◽  
Pneumatic Cylinder ◽  
Design Technique ◽  
Space Design ◽  
Damped Oscillations ◽  
Servo Controller ◽  
And Control

A closed-loop method of controlling a pneumatic cylinder is proposed where the cylinder can respond to varying position demands from an external source. The method uses a state space design technique involving the experimental identification of a dynamic model for the cylinder and valve combination. Data for the identification are obtained from an initial phase in which the valve and cylinder are excited by an operator. The controller constants are then derived using a pole placement design technique. The model and control constants are derived within the controller, resulting in automatic tuning. Experimental data are presented in response to step and ramp inputs. With moderate closed-loop bandwidths the response is well damped but as the designed bandwidth increases, lightly damped oscillations occur in the response, probably caused by differences between the responses of the experimental system and its model. If greater closed-loop bandwidths are required further work needs to be done on the form and order of the model.

Simultaneous Structural and Control Design Using Constraint Functions

1988 ◽  
Vol 110 (1) ◽  
pp. 65-72 ◽  
Author(s):  
J. M. Starkey ◽  
P. M. Kelecy
Keyword(s):  
Control System ◽  
System Dynamics ◽  
Structural Design ◽  
Closed Loop ◽  
Control Design ◽  
Pole Placement ◽  
Design Parameters ◽  
Weighted Sum ◽  
Design Technique ◽  
And Control

A design technique is presented which modifies system dynamics by simultaneously considering control system gains and structural design parameters. Constraint functions are devised that become smaller as (1) structural design parameters and feedback gains become smaller, and (2) closed-loop eigenvalues migrate toward more desirable regions. By minimizing a weighted sum of these functions, the interaction between design performance and design parameters can be explored. Examples are given that show the effects of the weighting parameters, and the potential advantages of this technique over traditional pole placement techniques.

scholarly journals From Beale Number to Pole Placement Design of a Free Piston Stirling Engine

2017 ◽  
Vol 64 (4) ◽  
pp. 499-518 ◽  
Author(s):  
Shahryar Zare ◽  
Alireza Tavakolpour-Saleh ◽  
Amir Omidvar
Keyword(s):  
Closed Loop ◽  
Design Procedure ◽  
Stirling Engine ◽  
Pole Placement ◽  
Design Parameters ◽  
Dynamic Systems Theory ◽  
Design Technique ◽  
Free Piston ◽  
Frictional Damping ◽  
Free Piston Stirling Engine

Abstract In this paper, pole placement-based design and analysis of a free piston Stirling engine (FPSE) is presented and compared to the well-defined Beale number design technique. First, dynamic and thermodynamic equations governing the engine system are extracted. Then, linear dynamics of the free piston Stirling engine are studied using dynamic systems theory tools such as root locus. Accordingly, the effects of variations of design parameters such as mass of pistons, stiffness of springs, and frictional damping on the locations of dominant closed-loop poles are investigated. The design procedure is thus conducted to place the dominant poles of the dynamic system at desired locations on the s-plane so that the unstable dynamics, which is the required criterion for energy generation, is achieved. Next, the closed-loop poles are selected based on a desired frequency so that a periodical system is found. Consequently, the design parameters, including mass and spring stiffness for both power and displacer pistons, are obtained. Finally, the engine power is calculated through the proposed control-based analysis and the result is compared to those of the experimental work and the Beale number approach. The outcomes of this work clearly reveal the effectiveness of the control-based design technique of FPSEs compared to the well-known approaches such as Beale number.

scholarly journals Modelling And Control Of Automated Polishing/Deburring Process

2021 ◽  
Author(s):  
Liang Liao
Keyword(s):  
Feedback Linearization ◽  
Closed Loop ◽  
Control Method ◽  
Minimum Degree ◽  
Open Loop ◽  
Pole Placement ◽  
Control Performance ◽  
Nonlinear Controller ◽  
Loop Control ◽  
And Control

In this thesis, a new approach is presented for the modelling and control of an automated polishing/deburring process that utilizes a dual-purpose complaint toolhead mounted on a parallel tripod robot. This toolhead has a pneumatic spindle that can be extended and retracted by three pneumatic actuators to provide tool compliance. By integrating a pressure sensor and a linear encoder, this toolhead can be used for polishing and deburring. For the polishing open-loop control, the desired tool pressure is pre-planned based on the given part geometry. To improve control performance, a closed-loop controller is applied for pressure tracking through pressure sensing. For the deburring control, another closed-loop controller is applied to regulate the tool length through tool extension sensing. The two control methods have been tested and implemented on a polishing/deburring robot, and the experiment results demonstrate the effectiveness of the presented methods. To future improve the control performance, an adaptive controller is developed to deal with the uncertainties in the compliant tool. This control method combines the adaptive control theory with the constant stress theory of the contact model. A recursive last squares (RLS) estimator is developed to estimate the pneumatic plant model, and then a minimum-degree pole placement (MDPP) is applied to design a self-tuning controller. Afterwards, the simulation and experiment results of the proposed controller are presented and discussed. Finally, a nonlinear model of the pneumatic plant is developed. The nonlinear controller developed by using feedback linearization method is applied on the nonlinear pneumatic system of the compliant toolhead. The simulation is carried out to test the effectiveness of the pressure tracking for the polishing process.

scholarly journals Robustly stable multiestimation scheme for adaptive control and identification with model reduction issues

2005 ◽  
Vol 2005 (1) ◽  
pp. 31-67 ◽  
Author(s):  
A. Bilbao-Guillerna ◽  
M. De La Sen ◽  
A. Ibeas ◽  
S. Alonso-Quesada
Keyword(s):  
Adaptive Control ◽  
Closed Loop ◽  
Dead Zone ◽  
Adaptive Controller ◽  
Pole Placement ◽  
Switching Rule ◽  
Estimation Scheme ◽  
On Line ◽  
Minimum Residence Time ◽  
And Control

A discrete pole-placement-based and multiestimation-based adaptive control scheme involving a relative adaptation dead zone is presented for a plant with known poles and unknown zeros. The basic usefulness of the proposed multiestimation scheme is related to the use of a set of models of reduced order associated with the multiestimation scheme instead of a high-order one. Depending on the frequency spectrum characteristics of the input and on the estimates evolution, the multiestimation scheme selects on-line the most appropriate model and its related estimation scheme in order to improve the identification and control performances. Robust closed-loop stability is proved even in the presence of unmodeled dynamics of sufficiently small sizes as it has been confirmed by simulation results. The scheme chooses in real time the estimator/controller associated with a particular reduced model possessing the best performance according to an identification performance index by implementing a switching rule between estimators. The switching rule is subject to a minimum residence time at each identifier/adaptive controller parameterization for closed-loop stabilization purposes. A conceptually simple higher-level supervisor, based on heuristic updating rules which estimate on-line the weights of the switching rule between estimation schemes, is discussed.

scholarly journals Modelling And Control Of Automated Polishing/Deburring Process

2021 ◽  
Author(s):  
Liang Liao
Keyword(s):  
Feedback Linearization ◽  
Closed Loop ◽  
Control Method ◽  
Minimum Degree ◽  
Open Loop ◽  
Pole Placement ◽  
Control Performance ◽  
Nonlinear Controller ◽  
Loop Control ◽  
And Control

In this thesis, a new approach is presented for the modelling and control of an automated polishing/deburring process that utilizes a dual-purpose complaint toolhead mounted on a parallel tripod robot. This toolhead has a pneumatic spindle that can be extended and retracted by three pneumatic actuators to provide tool compliance. By integrating a pressure sensor and a linear encoder, this toolhead can be used for polishing and deburring. For the polishing open-loop control, the desired tool pressure is pre-planned based on the given part geometry. To improve control performance, a closed-loop controller is applied for pressure tracking through pressure sensing. For the deburring control, another closed-loop controller is applied to regulate the tool length through tool extension sensing. The two control methods have been tested and implemented on a polishing/deburring robot, and the experiment results demonstrate the effectiveness of the presented methods. To future improve the control performance, an adaptive controller is developed to deal with the uncertainties in the compliant tool. This control method combines the adaptive control theory with the constant stress theory of the contact model. A recursive last squares (RLS) estimator is developed to estimate the pneumatic plant model, and then a minimum-degree pole placement (MDPP) is applied to design a self-tuning controller. Afterwards, the simulation and experiment results of the proposed controller are presented and discussed. Finally, a nonlinear model of the pneumatic plant is developed. The nonlinear controller developed by using feedback linearization method is applied on the nonlinear pneumatic system of the compliant toolhead. The simulation is carried out to test the effectiveness of the pressure tracking for the polishing process.

scholarly journals Design, Construction, and Control for an Underwater Vehicle Type Sepiida

Robotica ◽  
2020 ◽  
pp. 1-18
Author(s):  
M. Garcia ◽  
P. Castillo ◽  
E. Campos ◽  
R. Lozano
Keyword(s):  
Embedded System ◽  
Closed Loop ◽  
Underwater Vehicle ◽  
Mathematical Representation ◽  
Closed Loop System ◽  
Vehicle Type ◽  
Mathematical Equations ◽  
And Control ◽  
Design Construction

SUMMARY A novel underwater vehicle configuration with an operating principle as the Sepiida animal is presented and developed in this paper. The mathematical equations describing the movements of the vehicle are obtained using the Newton–Euler approach. An analysis of the dynamic model is done for control purposes. A prototype and its embedded system are developed for validating analytically and experimentally the proposed mathematical representation. A real-time characterization of one mass is done to relate the pitch angle with the radio of displacement of the mass. In addition, first validation of the closed-loop system is done using a linear controller.

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