2—THE SYSTEMATIC OPTIMIZATION OF THE AQUEOUS COMPRESSION-JET WOOL SCOUR. PART II: SCOURING TRIAL FOR OPTIMUM PRODUCTION CAPACITY

A factorial experiment performed on the aqueous compression-jet scour with three independent variables is reported. These variables were the feed-rate of greasy wool, the speed of the layer of wool, and the jetting pressures. The wools were processed to gilled slivers, on which mean-fibre-length determinations were made. The effects of the independent variables on the dependent variables of residual grease and dirt and mean fibre length (the last-named being a measure of the degree of entanglement of the scoured wool) were evaluated. The results obtained indicated the operating conditions to be used to achieve the optimum production capacity.     

FAULT DIAGNOSIS APPROACH BASED ON HIDDEN MARKOV MODEL AND SUPPORT VECTOR MACHINE

Aiming at solving the problems of machine-learning in fault diagnosis, a diagnosis approach is proposed based on hidden Markov model (HMM) and support vector machine (SVM). HMM usually describes intra-class measure well and is good at dealing with continuous dynamic signals. SVM expresses inter-class difference effectively and has perfect classify ability. This approach is built on the merit of HMM and SVM. Then, the experiment is made in the transmission system of a helicopter. With the features extracted from vibration signals in gearbox, this HMM-SVM based diagnostic approach is trained and used to monitor and diagnose the gearbox's faults. The result shows that this method is better than HMM-based and SVM-based diagnosing methods in higher diagnostic accuracy with small training samples.     

Probing Virtual Boundaries and the Perception of Delayed Stiffness

During interaction with robotic manipulanda, the human brain constructs internal representations of the environment imposed by the robotic device. These representations (i) provide cognitive interpretation of the interfaced environment and (ii) generate motor commands for future interaction with the imposed environment. Interestingly, cognitive and motor representations are not always mutually consistent. We consider a simple environment consisting of a spring-like surface, where either the delay between force and position or the location of the boundary is experimentally altered. We explored the cognitive representation of rigidity by asking subjects which of two surfaces is stiffer. We also considered the motor representation by investigating adaptation to the same virtual environments. We asked subject to reach a target inside virtual surface, and observed adaptation and its after effects in catch trials. In the cognitive study, we constructed psychometric curves based on the verbal reports of the subjects. In the motor study, we constructed analogous curves, which we name 'motormetric curves', describing the implicit motor expectation of rigidity, as expressed not verbally but by the errors in catch trials, where the delay was unexpectedly removed. We simulated motormetric curves from a simplified mechanical model of the arm and neural controller. We found that the cognitive reports reflected our measure of the motor behavior in the case of delayed stiffness, but not in the case of shifted boundary.     

Virtual Force/Tactile Sensors for Interactive Machines Using the User's Biological Signals

This study proposes a new approach to virtual realization of force/tactile sensors in machines equipped with no real sensors. The key of our approach is that a machine exploits the user's biological signals. Therefore, this approach is not dependent on controlled objects and is expected to be widely applicable for a variety of machines including robots. This article describes an example robotic system comprised of an industrial robot manipulator, a motion capture system and a surface electromyogram (EMG) measurement apparatus. By monitoring/recording the user's surface EMG and postural information in real-time, we show that a robot equipped with no force/tactile sensors behaved similarly to one possessing sensors over its body. Another advantage of our approach is demonstrated by a task in which a robot and a user cooperatively hold and move a heavy load.     

静态数据模型的形式化表示

本文论述了如何将OMT规范中的静态数据模型表示成BAMN中的MACHINE结构。     

A feature extraction method for galvanized steel sheet powdering rates classification

Abstract

This paper describes a feature extraction method for classifying galvanized steel sheet powdering rates. By combining machine vision with statistics, and using the standard deviation's difference between powdered and normal regions, the range of powdered areas is recognized. The method exhibits a number of interesting features: it uses mathematical statistics for image feature analysis, and develops an effective method for analyzing particle size which cannot be measured by manual detection. The experiment result shows that the correction rate of this method to acquire galvanized steel sheet powdered regions is up to 99%, which satisfies the requirements of the application.     

Formaldehyde and Benzoquinone Cross-links in Keratin—Reply

A study is reported in which fibre-length measurements were made on fibres withdrawn from a range of staples representing 21 sale lots of merino wool. The average variance of fibres within staples was 2.2 cm², and the estimates fell in the range 1.2–4.8 cm². Fibre-length variances within sale lots were estimated for six sale lots, and these ranged from 3.3 to 5.8 cm².

Both the ratio of average fibre length to staple length and the regression coefficients for these parameters varied over a wide range (e.g., from 1.1 to 1.6 for the ratios and from 0.4 to 1.0 for the regression coefficients). This variation, coupled with relatively low correlation coefficients, indicates that the use of staple length as a predictor of the average fibre length of greasy wool is inefficient. However, staple length may be a useful predictor of the average fibre length of wool tops.     

Terrain-evaluation-based motion planning for legged locomotion on irregular terrain

The path planning of legged locomotion is complex in that path generation is based on constraints not only from body motion, but also from leg motion. A general approach to path planning will fail in generating a feasible path for walking machines when facing the huge searching space of legged locomotion. In this paper, an effective method of path planning is introduced by virtue of terrain evaluation. It maps obstacles into the robot configuration space by evaluating the obstacles' influence on the legged locomotion. The evaluation produces an index of terrain, called terrain complexity, for path planning. Using potential-guided searching, the terrain with mapped obstacles is searched to generate a feasible path.     

43—FIBRE MIGRATION IN OPEN-END-SPUN YARNS

A study of the migration of fibres in open-end-spun yarns is reported. Samples of viscose rayon yarns were produced by the drum and air-vortex methods, and the results obtained on them were compared with those for a ring-spun yarn made from the same fibre. Migration was studied by determining three parameters: the helix profile, the mean fibre position, and the r.m.s. deviation, i.e., the root-mean-square value of the radial deviation of the helix profile from the mean fibre position. The geometry of fibre-packing in the yarn cross-section and the fibre extent were also studied.

It is shown that open-end-spun yarns are somewhat different in character from ring-spun yarns and that the most basic structural differences are found in the fibre extent, fibre migration, and fibre-packing density. The fibre migration in an open-end-spun yarn is shown to be as little as one-sixth of that in a typical ring-spun yam, and the difference in structure is important in that it can affect the yarn properties. It is concluded that the observed low strength of most open-end-spun yarns can be attributed to the poor fibre extent and inferior fibre migration within the yarn body and that their relatively high elongation can be explained in terms of the folded and entangled nature of the fibres.

An examination of the fibre geometry in the yarn shows that the design features of drum spinners are important with regard to the determination of the fibre extent, a tangential feed being preferable to an axial one.

The yarn cross-sections demonstrate that open-end spun yarns generally have a lower fibre-packing density than ring-spun yarns, which tends to give the yarn a more bulky nature; this is consistent with what might be expected from an assembly of tangled fibres.