Application of Double Closed-Loop Control to the Steady-State Regulation and Control of Underwater Vehicle

2012 ◽  
Vol 443-444 ◽  
pp. 548-552
Author(s):  
Liang Liu ◽  
Yu Yi Zhai ◽  
Wen Jie Lu ◽  
Huan Xin Luo ◽  
Yu Li

In this paper, the speed control system controlled by motor speed was designed to control forward speed of underwater robot precisely. Based on the theory of double closed-loop speed control, motor control system was modeled firstly, and then regulator parameters were designed based on the engineering approaches. According to the characteristics of forward movement, the mechanical construction of sub-mini underwater robots and the comparison of various system designs, the double closed-loop regulator parameters of sub-mini underwater robots were obtained. And the propulsion system of sub-mini underwater robots was equipped with speed and current double closed-loop control. All the experimental results showed that within a certain range of motor speed, no static error could be guaranteed and the variable speed of underwater vehicle could be achieved.

2014 ◽  
Vol 496-500 ◽  
pp. 1417-1421 ◽  
Author(s):  
Li Na Duan ◽  
Jin Zhao

The System is at the core of TMS320F2812DSP from TI company to design the control system for BLDC motor, the control segment of it take advantage of the event manager EVA of the DSP to compare and produce six ways signal control.And utilize the capture module to acquire the state situation of the rotor-position sensor.Acording to the condition of hall sensor to control motor commutation.And solve the PWM signal system in the generation and motor speed feedback.It's easy to realize the motor closed-loop control, greatly simplify the system hardware design, improves the reliability of the system, reduces the volume of the system. Through the experiments,we gain the PWM waveform, and finally realize the purpose of reverse control .


Author(s):  
Axel Fehrenbacher ◽  
Christopher B. Smith ◽  
Neil A. Duffie ◽  
Nicola J. Ferrier ◽  
Frank E. Pfefferkorn ◽  
...  

The objective of this research is to develop a closed-loop control system for robotic friction stir welding (FSW) that simultaneously controls force and temperature in order to maintain weld quality under various process disturbances. FSW is a solid-state joining process enabling welds with excellent metallurgical and mechanical properties, as well as significant energy consumption and cost savings compared to traditional fusion welding processes. During FSW, several process parameter and condition variations (thermal constraints, material properties, geometry, etc.) are present. The FSW process can be sensitive to these variations, which are commonly present in a production environment; hence, there is a significant need to control the process to assure high weld quality. Reliable FSW for a wide range of applications will require closed-loop control of certain process parameters. A linear multi-input-multi-output process model has been developed that captures the dynamic relations between two process inputs (commanded spindle speed and commanded vertical tool position) and two process outputs (interface temperature and axial force). A closed-loop controller was implemented that combines temperature and force control on an industrial robotic FSW system. The performance of the combined control system was demonstrated with successful command tracking and disturbance rejection. Within a certain range, desired axial forces and interface temperatures are achieved by automatically adjusting the spindle speed and the vertical tool position at the same time. The axial force and interface temperature is maintained during both thermal and geometric disturbances and thus weld quality can be maintained for a variety of conditions in which each control strategy applied independently could fail.


2017 ◽  
Vol 3 (2) ◽  
pp. 363-366
Author(s):  
Tobias Steege ◽  
Mathias Busek ◽  
Stefan Grünzner ◽  
Andrés Fabían Lasagni ◽  
Frank Sonntag

AbstractTo improve cell vitality, sufficient oxygen supply is an important factor. A deficiency in oxygen is called Hypoxia and can influence for example tumor growth or inflammatory processes. Hypoxia assays are usually performed with the help of animal or static human cell culture models. The main disadvantage of these methods is that the results are hardly transferable to the human physiology. Microfluidic 3D cell cultivation systems for perfused hypoxia assays may overcome this issue since they can mimic the in-vivo situation in the human body much better. Such a Hypoxia-on-a-Chip system was recently developed. The chip system consists of several individually laser-structured layers which are bonded using a hot press or chemical treatment. Oxygen sensing spots are integrated into the system which can be monitored continuously with an optical sensor by means of fluorescence lifetime detection.Hereby presented is the developed hard- and software requiered to control the oxygen content within this microfluidic system. This system forms a closed-loop control system which is parameterized and evaluated.


Author(s):  
Bahram Yaghooti ◽  
Ali Siahi Shadbad ◽  
Kaveh Safavi ◽  
Hassan Salarieh

In this article, an adaptive nonlinear controller is designed to synchronize two uncertain fractional-order chaotic systems using fractional-order sliding mode control. The controller structure and adaptation laws are chosen such that asymptotic stability of the closed-loop control system is guaranteed. The adaptation laws are being calculated from a proper sliding surface using the Lyapunov stability theory. This method guarantees the closed-loop control system robustness against the system uncertainties and external disturbances. Eventually, the presented method is used to synchronize two fractional-order gyro and Duffing systems, and the numerical simulation results demonstrate the effectiveness of this method.


2021 ◽  
Vol 20 ◽  
pp. 140-148
Author(s):  
Amir Salmaninejad ◽  
Rene V. Mayorga

A Direct Current (DC) Motor is usually supposed to be operated at a desired speed even if the load on the shaft is exposed to changes. One of its applications is in automatic door controllers like elevator automatic door drivers. Initially, to achieve this aim, a closed loop control can be applied. The speed feedback is usually prepared by a sensor (encoder or tachometer) coupled to the motor shaft. Most of these sensors do not always perform well, especially in elevator systems, where high levels of noise, physical tensions of the mobile car, and maintenance technicians walking on the car, make this environment too noisy. This Paper presents a new approach for precise closed loop control of the DC motor speed without a feedback sensor, while the output load is variable. The speed here is estimated by the Back EMF (BEMF) voltage obtained from the armature current. First, it is shown that a PID controller cannot control this process alone, and then intelligent controllers, Fuzzy Logic Controller (FLC) and Adaptive Neuro Fuzzy Inference Systems (ANFIS), assisting PID are applied to control this process. Finally, these controllers’ performance subjected to a variable mechanical load on the motor shaft are compared.


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