Cloud-Based AGV Control System

Zhang, Xiangnan; Gong, Wei; Xiang, Haolong; Chen, Yifei; Li, Dan; Wang, Yawei

doi:10.1007/978-3-030-48513-9_24

Cited by 1 publication

(1 citation statement)

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“…A PID controller approach was applied as it is wide-spread, so numerous practices for tuning the controller gains are available. The individual PID controller statements were transferred into G-code line by line [17]. Three controller gains had to be approximated: K P (proportional part), K I (integral part), and K D (derivative part).…”

Section: Powder Controlmentioning

confidence: 99%

In situ measurement and closed-loop control for powder supply processes

Breese

Hauser

Regulin

et al. 2021

Int J Adv Manuf Technol

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The powder mass flow rate is one of the main parameters regarding the geometrical precision of built components in the additive manufacturing process of laser metal deposition. However, its accuracy, constancy, and repeatability over the course of the running process is not given. Reasons among others are the performance of the powder conveyors, the complex nature of the powder behavior, and the resulting issues with existing closed-loop control approaches. Additionally, a direct in situ measurement of the powder mass flow rate is only possible with intrusive methods. This publication introduces a novel approach to measure the current powder mass flow rate at a frequency of 125 Hz. The volumetric powder flow evaluation given by a simple optical sensor concept was transferred to a mass flow rate through mathematical dependencies. They were found experimentally for a nickel-based powder (Inconel 625) and are valid for a wide range of mass flow rates. With this, the dynamic behavior of a vibration powder feeder was investigated and a memory effect dependent on previous powder feeder speeds was discovered. Next, a closed-loop control with the received sensor signal was implemented. The concept as a whole gives a repeatable and accurate powder mass flow rate while being universally retrofittable and applicable. In a final step, the improved dynamic and steady performance of the powder mass flow rate with closed-loop control was validated. It showed a reduction of mean relative errors for step responses of up to 81% compared to the uncontrolled cases.

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Section: Powder Controlmentioning

confidence: 99%