scholarly journals A two-stage thermal control method for cryocoolers cooling infrared optics

2014 ◽  
Author(s):  
Tao Yan ◽  
Yali Li ◽  
Jianguo Li ◽  
Guotong Hong
Keyword(s):  
Control Method ◽  
Thermal Control ◽  
Two Stage ◽  
Infrared Optics

scholarly journals A Two-Stage Quality Control Method for 2-m Temperature Observations Using Biweight Means and a Progressive EOF Analysis

2013 ◽  
Vol 141 (2) ◽  
pp. 798-808 ◽  
Author(s):  
Zhifang Xu ◽  
Yi Wang ◽  
Guangzhou Fan
Keyword(s):  
Quality Control ◽  
Control Method ◽  
Control Process ◽  
Lapse Rate ◽  
Systematic Bias ◽  
Eof Analysis ◽  
Two Stage ◽  
Quality Control Method ◽  
Quality Control Process ◽  
The Difference

Abstract The relatively smooth terrain embedded in the numerical model creates an elevation difference against the actual terrain, which in turn makes the quality control of 2-m temperature difficult when forecast or analysis fields are utilized in the process. In this paper, a two-stage quality control method is proposed to address the quality control of 2-m temperature, using biweight means and a progressive EOF analysis. The study is made to improve the quality control of the observed 2-m temperature collected by China and its neighboring areas, based on the 6-h T639 analysis from December 2009 to February 2010. Results show that the proposed two-stage quality control method can secure the needed quality control better, compared with a regular EOF quality control process. The new method is, in particular, able to remove the data that are dotted with consecutive errors but showing small fluctuations. Meanwhile, compared with the lapse rate of temperature method, the biweight mean method is able to remove the systematic bias generated by the model. It turns out that such methods make the distributions of observation increments (the difference between observation and background) more Gaussian-like, which ensures the data quality after the quality control.

scholarly journals Adaptive-MPPT-Based Control of Improved Photovoltaic Virtual Synchronous Generators

Energies ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1834 ◽  
Author(s):  
Xiangwu Yan ◽  
Jiajia Li ◽  
Ling Wang ◽  
Shuaishuai Zhao ◽  
Tie Li ◽  
...  
Keyword(s):  
Energy Storage ◽  
Control Method ◽  
Synchronous Generator ◽  
Storage Device ◽  
Stable Operation ◽  
Energy Storage Devices ◽  
Two Stage ◽  
Additional Energy ◽  
Control Approach ◽  
Pv Grid

The lack of inertia and damping mechanism of photovoltaic (PV) grid-connected systems controlled by maximum power point tracking (MPPT) poses a challenge for the safety and stability of the grid. Virtual synchronous generator (VSG) technology has attracted wide attention, since it can make PV grid-connected inverter present the external characteristics of a synchronous generator (SG). Nevertheless, traditional PV-VSG is generally equipped with an energy storage device, which leads to many problems, such as increased costs, space occupation, and post-maintenance. Thus, this paper proposes a two-stage improved PV-VSG control method based on an adaptive-MPPT algorithm. When PV power is adequate, the adaptive-MPPT allows the PV to change the operating point within a stable operation area to actualize system supply-demand, matching in accordance to the load or dispatching power demand; when PV power is insufficient, PV achieves traditional MPPT control to reduce power shortage; simultaneously, improved VSG control prevents the DC bus voltage from falling continuously to ensure its stability. The proposed control approach enables the two-stage PV-VSG to supply power to loads or connect to the grid without adding additional energy storage devices, the effectiveness of which in off-grid and grid-connected modes is demonstrated by typical simulation conditions.

Visual Comfort Control for Building Energy Management System

2012 ◽  
Vol 512-515 ◽  
pp. 2838-2841
Author(s):  
Shin Yen Lin ◽  
Wei Yuan Chen
Keyword(s):  
Energy Management ◽  
Control Algorithm ◽  
Control Method ◽  
Fuzzy Controller ◽  
Building Energy ◽  
Fine Tuning ◽  
Visual Comfort ◽  
Two Stage ◽  
Building Energy Management ◽  
Venetian Blind

In this paper, we propose a two-stage energy saving control algorithm to resolve the visual comfort control problem of building energy management systems (BEMS). The first stage control method consists of a fuzzy controller to control the venetian blind so as to exploit the outdoor luminance as much as possible while avoiding the sun glare. To remedy the possible imperfection caused by the fuzzy controller, a follow up fine tuning step is designed to adjust the outputs of the venetian blind resulted from the fuzzy controller. The second stage control is to determine whether to turn on the light based on the luminance measured by the sensor after the first stage control so as to save electricity. We have simulated the proposed two-stage control algorithm and demonstrate that the electricity saving can be up to 61% in the tested room.

A Novel Two-Stage Constant Force Compliant Microgripper

2020 ◽  
Vol 143 (5) ◽  
Author(s):  
Tingting Ye ◽  
Jie Ling ◽  
Xi Kang ◽  
Zhao Feng ◽  
Xiaohui Xiao
Keyword(s):  
Force Control ◽  
Integral Method ◽  
Control Method ◽  
Elliptic Integral ◽  
Negative Stiffness ◽  
Constant Force ◽  
Two Stage ◽  
Elliptic Integral Method ◽  
Dynamic Performances ◽  
Body Method

Abstract The manipulating objects of the micron scale are easily damaged, hence the microgrippers, the key components in micro manipulating systems, demand precise force control, plus miniaturized size. Consequently, the constant force microgrippers, generally lack the ability to fit different sizes. To avoid the overload damage, apply multi-size microparts and simplify the control method, a novel two-stage compliant constant force microgripper is proposed in this paper. Based on the negative stiffness effect, this gripper is connected in parallel with a two-stage negative stiffness module and a positive stiffness module. Then, the elliptic integral method and the pseudo-rigid-body method are both employed to derive the kinetostatic and dynamic performances. Finally, the analytical results are validated. It is observed that two-stage constant forces of 1.33 N in 305.6 μm and 1.11 N in 330.8 μm are acquired.

Kinematics-based end-effector path control of a mobile manipulator system on an uneven terrain using a two-stage Support Vector Machine

Robotica ◽  
2019 ◽  
Vol 38 (8) ◽  
pp. 1415-1433 ◽  
Author(s):  
Hitesh Jangid ◽  
Subham Jain ◽  
Beteley Teka ◽  
Rekha Raja ◽  
Ashish Dutta
Keyword(s):  
Support Vector Machine ◽  
Control Method ◽  
Microsoft Kinect ◽  
Mobile Manipulator ◽  
Support Vector ◽  
Joint Probability Distribution ◽  
Total System ◽  
Two Stage ◽  
End Effector ◽  
Uneven Terrain

SUMMARYA mobile manipulator system (MMS) consists of a robotic arm mounted on a mobile platform that is used in rescue and relief, space exploration, warehouse automation, etc. As the total system has 14 Degrees of Freedom (DOF), it does not have a closed-form inverse kinematics (IK) solution. A learning-based method is proposed, which uses the forward kinematics data to learn the IK relation for motion of an MMS on a rough terrain, using a one-class support vector machine (SVM) framework. Once trained, the model estimates the joint probability distribution of the MMS configuration and end-effector position. This distribution is used to find the MMS configuration for a given desired end-effector path. Past research using a Kohonen Self organizing map (KSOM) neural network-based open-loop control method has shown that the MMS deviates from its desired path while moving on an uneven terrain due to unknown disturbances such as wheel slip, slide, and terrain deformation. Therefore, a new sequential two-stage SVM-based end-effector path-tracking control scheme is proposed to control the end-effector path. In this scheme, the error in the end-effector path is continuously tracked with the help of a Microsoft Kinect 2.0 (Microsoft Regional Sales, Singapore 119968) and is sent as a feedback to the controller. Once the error reaches a threshold value, the error correction step of the controller gets activated to correct the error until the desired accuracy is reached. The effectiveness of the proposed approach is proved through extensive simulations and experiments conducted on 3D terrain in which it is shown that the end effector can follow the desired path with an average experimental error of around 2 cm between the desired and final corrected path.

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