Study and redesign of high temperature batch annealing furnace for production of grain oriented electrical steel

Abstract

Grain oriented electrical steel coils are batch annealed at 1200°C to develop the magnetic properties of the strip. Temperature gradients are known to exist within the coils, which can affect the three important reactions occurring in the steel during annealing. These gradients result from the anisotropic conduction properties of the coil and the application of furnace heat. Heat is applied from the furnace to the coil in the radial direction. Studies of the conduction properties of an electrical steel coil have shown that the radial coefficient is ～20% of the axial coefficient. Computational fluid dynamics was employed to simulate a furnace redesign, comprising increased axial heating and a larger coil size. The results show that the annealing cycle time may be shortened and annealing conditions simultaneously improved. The difference between process requirements and process performance can be significantly narrowed by use of the redesigned furnace.     

Biological Insights Into Robotics: Honeybee Foraging Behavior by a Waggle Dance

A honeybee informs her nestmates of flower locations by a unique behavior called a 'waggle dance'. We regard this behavior as a good model of the 'propagation and sharing of knowledge' to maintain a society. We have attempted to reveal how this dance benefits the colony using mathematical models and computer simulation based on parameters obtained from observations of bee behavior. Our simulation indicated that the most successful forages were made by a putative bee colony that used the dance to communicate. Video analysis of worker honeybee behavior in the field showed that a bee does not dance in a single, random place in the hive, but waggles several times in one place and several times in another. The orientation and duration of waggle runs varied from run to run, within ranges of ±15° and ±15%, respectively. We also found that most of the bees that listened to the waggle dance turned away from the dancer after listening to one or two runs. These data suggest that honeybees use the waggle dance as a method of communication, but that they must base their forages on ambiguous information about the location of a food source.     

The life of a plant builder in the modern metals industry

Abstract

The 2007 SMEA Celebrity Lecture (Sheffield Metallurgical and Engineering Association) was given by Roy Tazzyman, the outgoing Managing Director of Siemens VAI–UK, on 4 July 2007 at the University of Sheffield, in conjunction with the Association's annual conference. Ken Ridal summarises the proceedings.     

Lower Irritation Potential of Laureth‐3 Carboxylate Amino Acid Salt

Sodium laureth sulfate and amino acid type surfactants have been categorized as low‐skin irritation chemicals based on results of previous skin irritation tests. However, detergent‐induced skin irritation still occurs. Detergents with a low‐skin irritation effect are required, since the number of cosmetics for sensitive skin has increased. Therefore, an in vitro method of testing the safety of cosmetics for sensitive skin is required. Skin irritation by anionic surfactants was investigated to determine the effect of laureth‐3 carboxylate (polyoxyethylene lauryl carboxymethyl ether) amino acid salt on skin irritation. In addition, sodium laureth sulfate and amino acid type surfactants, regarded as low‐irritation surfactants, were also tested for skin irritation. The skin irritation effect of laureth‐3 carboxylate lysine salt (Surfactant 1 ), sodium laureth sulfate (Surfactant 2 ), and sodium N‐lauroyl glutamate (Surfactant 3 ) were investigated using a reconstructed human cultured epidermal model, LabCyte EPI‐MODEL24 6D. Cell viabilities of cultured epidermal cells exposed to Surfactant 1 (5.0 % aq.), Surfactant 2 , and Surfactant 3 were 82.0, 45.0 and 19.1 %, respectively. There were significant differences in cell viability upon exposure to 5.0 % aqueous test solutions of the three test chemicals. The results of the current investigation indicate that Surfactant 1 has a low skin‐irritation effect.     

DEVELOPMENT OF CALCULATING MODEL APPLICABLE FOR CYLINDER WALL DYNAMIC HEAT TRANSFER

In the calculation of submarine air conditioning load of the early stage, the obtained heat is regarded as cooling load. The confusion of the two words causing the cooling load figured out is abnormally high, and the change of air conditioning cooling load can not be indicated. In accordance with submarine structure and heat transfer characteristics of its inner components, Laplace transformation to heat conduction differential equation of cylinder wall is carried out. The dynamic calculation of submarine conditioning load based on this model is also conducted, and the results of calculation are compared with those of static cooling load calculation. It is concluded that the dynamic cooling load calculation methods can illustrate the change of submarine air conditioning cooling load more accurate than the static one.     

MODELING METHOD OF 4D INFORMATION MODEL FOR COOPERATIVE DESIGN OF MECHANICAL PRODUCTS

The continuous developing features in the design of mechanical product and based on 3D entity model is aimed at, and the extension of the 4-dimensional model with the process of designing, the knowledge described model on the level of semantic understanding and summarizing the designing process and the way of discovering knowledge from multi-information model are studied. On the basis of designing the broad sensed collaborative system, through discussion of the relationship between the implicit knowledge of the users and the designing knowledge as well as commanding all the designing links, taking advantage of the way of concluding and deducting in the concept of the designers, the synthetic knowledge unit formed in the dynamic process from the conception design to the last design is schemed out, and the knowledge discovered principle in the dynamic designing process of the mechanical products and the key technology in its implementation under the milieu of network is brought forward.     

Modeling and time delay control of shape memory alloy actuators

Shape memory alloy (SMA) actuators possess hard nonlinearities including backlash-like hysteresis and saturation. These nonlinearities result in steady-state error and limit-cycle problems when conventional controllers such as the proportional integral derivative (PID) are used for trajectory control. In this study, a dynamics for an SMA actuator was newly derived using the modified Liang's model. The derived dynamics showed continuity at the change of the phase transformation process, but the original model could not. SMA actuator characteristics could be well described using this dynamics. The derived dynamics could be also used effectively for the prediction of control performance and gain tuning of the time delay control (TDC). The dynamics consisted of first-order linear and second-order nonlinear equations. Accordingly, a control strategy was established for the TDC to regulate only the second-order nonlinear part for simplicity and for the internal closed loop to regulate the rest. The control strategy was examined from the point of view of influence of an antiwindup scheme and high gain tuning on control performance. An anti-windup scheme was essential to protect windup phenomenon and high gain tuning was effective when a temperature disturbance existed. In the robustness test, the TDC with high gains showed robustness to inertia variation and temperature disturbance in comparison with the TDC with low gains.     

An evolutionary algorithm for simultaneous localization and mapping (SLAM) of mobile robots

This paper presents a novel algorithm for simultaneous localization and mapping (SLAM) of mobile robots. The algorithm, termed Evolutionary SLAM, is based on an island model genetic algorithm (IGA). The IGA searches for the most probable map(s) such that the underlying robot's pose(s) provide(s) a robot with the best localization information. The correspondence problem in SLAM is solved by exploiting the property of natural selection, to support only better-performing individuals to survive. The algorithm does not follow any explicit heuristics for loop closure, rather it maintains multiple hypotheses to solve the loop-closing problem. The algorithm processes sensor data incrementally and, therefore, has the capability to work online. Experimental results in different indoor environments validate the robustness of the proposed algorithm.     

Kinematic modeling of wheeled mobile robots with slip

This work presents a kinematic modeling method for wheeled mobile robots with slip based on physical principles. First, we present the kinematic modeling of a mobile robot with no-slip considering four types of wheels: fixed, centered orientable, off-centered orientable (castor) and Swedish (also called Mecanum, Ilon or universal). Then, the dynamics of a wheeled mobile robot based on Lagrange formulation are derived and discussed. Next, a quasi-static motion is considered to obtain the kinematic conditions that provide the slip modeling equations. Several types of traction models for the slip between the wheel and the floor are indicated. In particular, for a frictional force linearly dependent on the sliding velocity, the no-slip kinematic equation of the wheeled mobile robot is related, through the weighted least-squares algorithm, with the slip modeling equations. To illustrate the applications of the proposed approach a tricycle vehicle is considered in a real situation. The experimental results obtained for the slip kinematic model are compared with the ones obtained for the well-known Kalman filter.     

Kinematic modeling and singularity of wheeled mobile robots

This paper presents a global singularity analysis for wheeled mobile robots (WMRs). First, a kinematic model of a generic wheel is obtained using a recursive kinematics formulation. This novel and efficient approach is valid for all the common types of wheels: fixed, centered orientable, off-centered orientable (caster or castor) and Swedish or Mecanum. Then, a procedure for generating robot kinematic models is presented based on the set of wheel equations and the null space concept. Next, the singularity of kinematic models is discussed: first, the kinematic singularity condition in forward models is obtained, and then the singularity condition in inverse, or even mixed, models. A generic and practical geometric approach is established to characterize the singularity of any kinematic model of any WMR with the mentioned wheels. To illustrate the applications of the proposed approach, the singular configurations for many types of WMRs are depicted. Finally, the singularity characterization is extended to include other specialized wheels: dual-wheel, dual-wheel castor, ball-type and orthogonal.