Design and Improvement on a Stress Loading Device for Ligament Tissue Engineering

2013 ◽  
Vol 325-326 ◽  
pp. 267-270
Author(s):  
Xiu De Wu ◽  
Xiong Wang

Strain loading control is important for addressing the complex requirements of tissue engineering in bioreactor. The stress variation laws of the engineering tissue during growth were analyzed, and the strain loading rules were determined. A new mechanical stress loading device was developed, which was able to apply complex concurrent mechanical strains to three-dimensional scaffolds independently housed in reactor chambers. The AC servo control system was used to carry out tensional and rotational displacements. Well controlled mechanical stimulations could be applied to the developing ligament tissue, through the closed-loop control system for stresses, allowed different mechanical loading patterns on the scaffolds. We analyzed the strains of scaffolds fixed in circular and planar modes. The strain, motion, and position control methods were designed. This device is suitable for the bioreactor used in ligament tissue engineering.

2011 ◽  
Vol 127 ◽  
pp. 126-129
Author(s):  
Li Hong Wang ◽  
Yue Ling Zhao

A stepping motor position closed loop control system was designed, which adopts displacement sensor to examine the position of the load. The system’s hardware constitute was given here, and the pulse control project was given at the same time. It uses the high-speed pulse output of PLC to export the adjustable frequency pulse. The adjustment of the frequency based on the error of initial value and actual value. On one hand, it can realize fast and accurate position control. On the other hand, it can overcome the weakness of losing step. Thus makes the system have better control function.


2011 ◽  
Vol 219-220 ◽  
pp. 3-7
Author(s):  
Ning Zhang ◽  
Rong Hua Liu

An expert control system based on transient response patterns and expert system techniques is proposed in this paper. Depending on the features of the closed-loop control system determines the control decision and adjusts the parameters of the controller. The proposed method requires minimal proper information about the controlled plant and, with the linear re-excitation learning method, the system is kept satisfying the performance criterion.


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.


2012 ◽  
Vol 229-231 ◽  
pp. 2201-2204
Author(s):  
Cun Hai Pan ◽  
Hui Li ◽  
Su Mei Du ◽  
Wei Gao

A twin-rotary motion control system was built based on a cam technology and Siemens S7-300T PLC in this paper. The system can position accurately in a three-dimension space using a twin-servo closed loop control system and can real-time monitor various parameters of positioning system by HMI (Human Machine Interface). It also can automatically collect various parameter information and judge the type of fault.At the same time, the degree of automation has been raised and the cost of production was reduced.


2018 ◽  
Vol 42 (3) ◽  
pp. 323-339
Author(s):  
Jicheng Liu ◽  
Jinshuai Yang ◽  
Binglu Yan ◽  
Zheng Liu

A new category of large-diameter adaptable amphibious wheel-legged robot is proposed in this paper. The proposed mechanism can climb obstacles better than existing designs. The Denavit–Hartenberg (D–H) coordinate system is used for kinematic analysis, and the constructed kinematic model is used to solve for these joint variables for a redundant robot. The control strategy is to plan both the foot trajectory of the amphibious robot, to optimize the operational performance in special environments, as well as the walking gait. Then the closed-loop control system is used. A simulation is used to verify the usefulness of the planned foot trajectory and walking gait for an entire running cycle, and a circuit is designed to solve a communication problem between the Arduino and the AX-12 servo. Finally, the foot trajectory of a single robot leg is captured by a three-dimensional motion-capture system to verify the rationality of the foot trajectory and walking gait.


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