Hybrid Control of Flowrate in Microextrusion-Based Direct-Write Additive Manufacturing
| Autor: | Ali Asghari Adib, David J. Hoelzle |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Lyapunov function
0209 industrial biotechnology Control and Optimization Computer science Open-loop controller Microextrusion 02 engineering and technology Sense (electronics) 021001 nanoscience & nanotechnology Stability (probability) Pressure sensor symbols.namesake 020901 industrial engineering & automation Control and Systems Engineering Control theory Control system symbols 0210 nano-technology Marginal stability |
| Zdroj: | ACC |
| DOI: | 10.23919/acc50511.2021.9483215 |
| Popis: | Flowrate control has been a continuous challenge in Direct-Write Additive Manufacturing (DW AM) due to capacitive energy storage in the system and the lack of suitable flowrate sensors at the microscale, resulting in poor dimensional control of material addition. While a pressure sensor can be used for pressure-based feedback control, the system will become marginally stable if the material loses contact with the pressure sensor, and thus feedback is lost. In this letter, we design and implement a pressure-based hybrid controller with a state-dependent switching strategy that eliminates the stability problem due to a loss of pressure feedback, and thus enables the real time, stable control of flowrate in DW AM. The stability of the hybrid controller is assessed using phase portraits and Multiple Lyapunov-like Functions. The hybrid dynamical model and the hybrid controller are experimentally implemented and validated. Stability results indicate that the hybrid controller resolved the marginal stability issue, and is stable in the sense of Lyapunov. Moreover, the hybrid control scheme implementation in the case study demonstrated that the shape fidelity of the parts is appreciably enhanced compared to the open loop control case. |
| Databáze: | OpenAIRE |
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