Thermodynamic Modeling and Control of Screw Extruder for 3D Printing

Koga, Shumon; Straub, David; Krstić, Miroslav

doi:10.23919/acc.2018.8431649

Cited by 13 publications

(16 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Proof. By the energy-conservation (18) and control law given by (22), one can derive that the closed-loop system has the explicit solution for the state feedback control q c (t) given by…”

Section: Some Conditions Required For Model Validitymentioning

confidence: 99%

“…However, the control design derived from w x (0,t) = 0 does not ensure the positivity and the required conditions addressed in Lemma 6. As proposed in Section 3, we design the control law (22) by means of energy shaping to guarantee the required conditions, which is rewritten as…”

Section: Backstepping Transformationmentioning

confidence: 99%

“…The control design (22) requires the physical parameters of both the liquid and solid phases, however, in practice these parameters are uncertain. Guaranteeing the robustness of the stability of the closed-loop system with respect to such parametric uncertainties is significant.…”

Section: Robustness To Uncertainties Of Physical Parametersmentioning

confidence: 99%

“…are more restrictive than Assumption 3 for the unperturbed design (22), which causes a tradeoff between the parameters' uncertainty and the restriction of the setpoint. The proof of Theorem 2 is established by following similar steps to Section 4. which is developed in our previous work in [17] for the onephase Stefan problem (hereafter "one-phase design").…”

Section: Robustness To Uncertainties Of Physical Parametersmentioning

confidence: 99%

“…Liquid-solid phase transitions are physical phenomena which appear in various kinds of science and engineering processes. Representative applications include sea-ice melting and freezing [25], continuous casting of steel [33], cancer treatment by cryosurgeries [34], additive manufacturing for materials of both polymer [22] and metal [5], crystal growth [6], lithium-ion batteries [21], and thermal energy storage systems [37]. Physically, these processes are described by a temperature profile along a liquid-solid material, where the dynamics of the liquidsolid interface is influenced by the heat flux induced by melting or solidification.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Single-boundary control of the two-phase Stefan system

Koga

Krstić

2020

Systems & Control Letters

Self Cite

View full text Add to dashboard Cite

This paper presents the control design of the two-phase Stefan problem. The two-phase Stefan problem is a representative model of liquid-solid phase transition by describing the time evolutions of the temperature profile which is divided by subdomains of liquid and solid phases as the liquid-solid moving interface position. The mathematical formulation is given by two diffusion partial differential equations (PDEs) defined on a time-varying spatial domain described by an ordinary differential equation (ODE) driven by the Neumann boundary values of both PDE states, resulting in a nonlinear coupled PDE-ODE-PDE system. We design a state feedback control law by means of energy-shaping to stabilize the interface position to a desired setpoint by using single boundary heat input. We prove that the closed-loop system under the control law ensures some conditions for model validity and the global exponential stability estimate is shown in L 2 norm. Furthermore, the robustness of the closed-loop stability with respect to the uncertainties of the physical parameters is shown. Numerical simulation is provided to illustrate the good performance of the proposed control law in comparison to the control design for the one-phase Stefan problem.

show abstract

“…Proof. By the energy-conservation (18) and control law given by (22), one can derive that the closed-loop system has the explicit solution for the state feedback control q c (t) given by…”

Section: Some Conditions Required For Model Validitymentioning

confidence: 99%

Section: Backstepping Transformationmentioning

confidence: 99%

Section: Robustness To Uncertainties Of Physical Parametersmentioning

confidence: 99%

Section: Robustness To Uncertainties Of Physical Parametersmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Single-boundary control of the two-phase Stefan system

Koga

Krstić

2020

Systems & Control Letters

Self Cite

View full text Add to dashboard Cite

show abstract

Delay compensated control of the Stefan problem and robustness to delay mismatch

Koga

Bresch‐Pietri

Krstić

2020

Intl J Robust & Nonlinear

Self Cite

View full text Add to dashboard Cite

Summary This paper presents a control design for the one‐phase Stefan problem under actuator delay via a backstepping method. The Stefan problem represents a liquid‐solid phase change phenomenon which describes the time evolution of a material's temperature profile and the interface position. The actuator delay is modeled by a first‐order hyperbolic partial differential equation (PDE), resulting in a cascaded transport‐diffusion PDE system defined on a time‐varying spatial domain described by an ordinary differential equation (ODE). Two nonlinear backstepping transformations are utilized for the control design. The setpoint restriction is given to guarantee a physical constraint on the proposed controller for the melting process. This constraint ensures the exponential convergence of the moving interface to a setpoint and the exponential stability of the temperature equilibrium profile and the delayed controller in the ℋ1 norm. Furthermore, robustness analysis with respect to the delay mismatch between the plant and the controller is studied, which provides analogous results to the exact compensation by restricting the control gain.

show abstract

Polymer materials for additive manufacturing

2022

Digital Manufacturing

View full text Add to dashboard Cite

Thermodynamic Modeling and Control of Screw Extruder for 3D Printing

Cited by 13 publications

References 18 publications

Single-boundary control of the two-phase Stefan system

Single-boundary control of the two-phase Stefan system

Delay compensated control of the Stefan problem and robustness to delay mismatch

Polymer materials for additive manufacturing

Contact Info

Product

Resources

About