A new type of variable structure temperature programming controller

1998 ◽  
Vol 2 (3) ◽  
pp. 249-251
Author(s):  
Ruisen Lin ◽  
Xu Yaoliang
Keyword(s):  
Variable Structure ◽  
Temperature Programming ◽  
New Type

Moving Sliding Surfaces for Fast Tracking Control of Second-Order Dynamical Systems

1994 ◽  
Vol 116 (1) ◽  
pp. 154-158 ◽  
Author(s):  
Seung-Bok Choi ◽  
Dong-Won Park
Keyword(s):  
Dynamical Systems ◽  
Initial Conditions ◽  
Variable Structure ◽  
Second Order ◽  
Sliding Surface ◽  
Structure Control ◽  
Fast Tracking ◽  
Control Gain ◽  
New Type ◽  
Representative Points

A new type of sliding surface for a variable structure control system is proposed to achieve fast and accurate path tracking in a class of nonlinear second-order multi-input dynamical systems. The surface is adaptable to arbitrary initial conditions, and movable towards a predetermined surface. The movement is executed in a stepwise manner according to the trajectory of representative points. We call it a moving sliding surface (MSS). Using the MSS favorable fast tracking is accomplished without increasing the magnitude of the discontinuous control gain. A two-degree-of-freedom robotic manipulator subjected to external disturbances is considered to demonstrate the efficacy of the proposed method.

Trajectory Designing and Realizing for the Variable Structure Motorcycle Helmet

2011 ◽  
Vol 328-330 ◽  
pp. 633-637
Author(s):  
Ai Nong Geng ◽  
Xin Mo Li ◽  
Yu Xing Xie
Keyword(s):  
Trajectory Planning ◽  
Variable Structure ◽  
Motorcycle Helmet ◽  
Double Movement ◽  
New Type ◽  
Design Requirements ◽  
Design Case ◽  
Double Track

A new type of variable structure motorcycle helmet is proposed in this paper, in which that the helmet’s chin-guard can be transformed between the full-helmet status and the half-helmet status as needed. The helmet creatively adopts double movement nails and double track grooves to constraint the chin-guard movement according to the predetermined trajectory, and thus smoothly accomplishing the chin-guard’s lifting, climbing, passing zenith, falling and closing in the helmet shell. The paper introduces the chin-guard’s trajectory planning principles, realizing methods and designing steps, and then gives a design case for the constraint slot tracks in detail. The results show that the new type helmet can reliably realize helmet structure conversion between full-helmet and half-helmet and fully meets the design requirements.

scholarly journals A Novel Smooth Variable Structure Smoother for Robust Estimation

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1781
Author(s):  
Yu Chen ◽  
Luping Xu ◽  
Bo Yan ◽  
Cong Li
Keyword(s):  
Sliding Mode ◽  
Variable Structure ◽  
Estimation Accuracy ◽  
Maneuvering Target Tracking ◽  
State Estimate ◽  
Maneuvering Target ◽  
Modeling Uncertainties ◽  
New Type ◽  
Gaussian System ◽  
Smooth Variable Structure Filter

The smooth variable structure filter (SVSF) is a new-type filter based on the sliding-mode concepts and has good stability and robustness in overcoming the modeling uncertainties and errors. However, SVSF is insufficient to suppress Gaussian noise. A novel smooth variable structure smoother (SVSS) based on SVSF is presented here, which mainly focuses on this drawback and improves the SVSF estimation accuracy of the system. The estimation of the linear Gaussian system state based on SVSS is divided into two steps: Firstly, the SVSF state estimate and covariance are computed during the forward pass in time. Then, the smoothed state estimate is computed during the backward pass by using the innovation of the measured values and covariance estimate matrix. According to the simulation results with respect to the maneuvering target tracking, SVSS has a better performance compared with another smoother based on SVSF and the Kalman smoother in different tracking scenarios. Therefore, the SVSS proposed in this paper could be widely applied in the field of state estimation in dynamic system.

Sliding Mode Control for Singular Systems with Variable Switched Surface

2013 ◽  
Vol 651 ◽  
pp. 967-975
Author(s):  
Jing Xie ◽  
Cun Chen Gao ◽  
Chong Zhang
Keyword(s):  
Sliding Mode ◽  
Singular Systems ◽  
Variable Structure ◽  
Minimum Time ◽  
Integral Type ◽  
Switching Sequence ◽  
Structure Control ◽  
Sliding Surfaces ◽  
New Type ◽  
Sliding Mode Variable Structure

The problem of minimum time sliding mode variable structure control is researched for a singular continuous linear system on variable reaching surfaces. Firstly, a sufficient condition for asymptotic stability of two switching subsystems’ sliding movements is deduced on integral-type sliding surfaces. Secondly, a new-type reaching law is designed, so that reaching surfaces of subsystems’ state trajectories tend to sliding surfaces at certain rates and finally coincide with them. Thirdly, an estimated value of the minimum time is calculated as less as possible for reaching surfaces to sliding surfaces. And a switching sequence is designed to make two subsystems reach hierarchically to sliding mode and then converge in a neighborhood of the origin. Finally, the effectiveness and the feasibility are illustrated for the proposed method by a simulation example.

Machines on the Basis of Variable Structure Mechanisms (VSM)

2006 ◽  
Author(s):  
Samudin Abdraimov ◽  
Nazira Samudinovna Abdraimova
Keyword(s):  
Power Consumption ◽  
Variable Structure ◽  
Output Link ◽  
Considerable Part ◽  
Unique Possibility ◽  
New Type ◽  
Machine Parts ◽  
Laws Of Motion ◽  
Force Displacement

The new type of mechanisms — the variable structure mechanisms (VSM) possess a unique possibility of rapid and practically instantaneous transformation of the motion law of actuating link under influence of insignificant non-force displacement of one of the kinematical elements without breaking up the entire kinematical chain. The main feature of VSM is in its ability to fulfill two and more laws of motion by output link. The change of motion law for lever mechanisms occurs without disruption in the kinematical chain and thus enables to expend less effort and time. Whereas the couplings, brakes and other power impact elements control the block of interacting mechanisms till now, this results in disruption of entire kinematical chain. A considerable part of power will be required to put these elements into action. This results in decrease of machine efficiency and, especially, extremely influences the machine parts’ durability. The variable structure mechanisms (VSM) exclude such supplementary operative power consumption elements.

The Microstructure of Shock-Synthesized Diamond

1967 ◽  
Vol 25 ◽  
pp. 324-325
Author(s):  
Lucien F. Trueb
Keyword(s):  
Single Crystals ◽  
Preferred Orientation ◽  
High Magnification ◽  
Texture Pattern ◽  
Shock Process ◽  
New Type ◽  
Diffraction Diagram

A new type of synthetic industrial diamond formed by an explosive shock process has been recently developed by the Du Pont Company. This material consists of a mixture of two basically different forms, as shown in Figure 1: relatively flat and compact aggregates of acicular crystallites, and single crystals in the form of irregular polyhedra with straight edges.Figure 2 is a high magnification micrograph typical for the fibrous aggregates; it shows that they are composed of bundles of crystallites 0.05-0.3 μ long and 0.02 μ. wide. The selected area diffraction diagram (insert in Figure 2) consists of a weak polycrystalline ring pattern and a strong texture pattern with arc reflections. The latter results from crystals having preferred orientation, which shows that in a given particle most fibrils have a similar orientation.

New type electron gun with electrostatic and electromagnetic lenses

1978 ◽  
Vol 36 (1) ◽  
pp. 62-63
Author(s):  
T. Ichinokawa ◽  
H. Maeda
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Optimum Condition ◽  
Bias Voltage ◽  
Electron Gun ◽  
Charge Effect ◽  
Micro Fabrication ◽  
Maximum Brightness ◽  
New Type ◽  
The Ideal

I. IntroductionThermionic electron gun with the Wehnelt grid is popularly used in the electron microscopy and electron beam micro-fabrication. It is well known that this gun could get the ideal brightness caluculated from the Lengumier and Richardson equations under the optimum condition. However, the design and ajustment to the optimum condition is not so easy. The gun has following properties with respect to the Wehnelt bias; (1) The maximum brightness is got only in the optimum bias. (2) In the larger bias than the optimum, the brightness decreases with increasing the bias voltage on account of the space charge effect. (3) In the smaller bias than the optimum, the brightness decreases with bias voltage on account of spreading of the cross over spot due to the aberrations of the electrostatic immersion lens.In the present experiment, a new type electron gun with the electrostatic and electromagnetic lens is designed, and its properties are examined experimentally.

A new type of defect structure in 124-superconducting oxide revealed by HREM

1991 ◽  
Vol 49 ◽  
pp. 1092-1093
Author(s):  
R. Sharma ◽  
B.L. Ramakrishna ◽  
N.N. Thadhani ◽  
D. Hianes ◽  
Z. Iqbal
Keyword(s):  
Shock Wave ◽  
Defect Structure ◽  
Neutron Radiation ◽  
Weak Links ◽  
Defect Structures ◽  
New Materials ◽  
New Type ◽  
Current Densities ◽  
Processing Techniques ◽  
Microstructural Studies

After materials with superconducting temperatures higher than liquid nitrogen have been prepared, more emphasis has been on increasing the current densities (Jc) of high Tc superconductors than finding new materials with higher transition temperatures. Different processing techniques i.e thin films, shock wave processing, neutron radiation etc. have been applied in order to increase Jc. Microstructural studies of compounds thus prepared have shown either a decrease in gram boundaries that act as weak-links or increase in defect structure that act as flux-pinning centers. We have studied shock wave synthesized Tl-Ba-Cu-O and shock wave processed Y-123 superconductors with somewhat different properties compared to those prepared by solid-state reaction. Here we report the defect structures observed in the shock-processed Y-124 superconductors.

ESEM - A multipurpose surface Electron Microscope

1986 ◽  
Vol 44 ◽  
pp. 632-633 ◽  
Author(s):  
G.D. Danilatos
Keyword(s):  
Electron Microscope ◽  
Room Temperature ◽  
Environmental Scanning ◽  
Gas Composition ◽  
Saturated Water Vapor ◽  
Surface Electron ◽  
Current State ◽  
Saturated Water ◽  
New Type ◽  
Temperature And Pressure

Over recent years a new type of electron microscope - the environmental scanning electron microscope (ESEM) - has been developed for the examination of specimen surfaces in the presence of gases. A detailed series of reports on the system has appeared elsewhere. A review summary of the current state and potential of the system is presented here.The gas composition, temperature and pressure can be varied in the specimen chamber of the ESEM. With air, the pressure can be up to one atmosphere (about 1000 mbar). Environments with fully saturated water vapor only at room temperature (20-30 mbar) can be easily maintained whilst liquid water or other solutions, together with uncoated specimens, can be imaged routinely during various applications.

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