Construction and Experimental Study of a 3-Dof Haptic Master for Interactive Operation

This paper presents a novel 3-degrees-of-freedom (3-DOF) haptic master with rubber bands for self-resetting. The mechanical design avoids coupling between three directions mechanically by using three perpendicular axis intersecting at one point. Bevel gear transmission is adopted to increase the compactness of the overall structure. VR-based interactive system is designed and built by incorporating the proposed haptic master. The proposed haptic device can generate force feedback along 3-degree-of-freedom motion using motors and provide command signals to the avatar in the virtual environment. In order to analyze the performance of the developed device in terms of haptic feedback operation, ergonomics assessments are designed and experimentally implemented. Preliminary studies on the influencing factor including the guidance force, the reset force, the speed of the avatar and the arm the length have been conducted. The results of this paper are of great significance for the design of the haptic master and interactive system.

New Method of Measurements of Magnetic Characteristics in Two Perpendicular Axis of Amorphous Ribbon

The paper presents new method, which enables measurement of magnetic characteristics of amorphous alloy ribbons in two directions. In presented method a frame shaped core is placed in middle layer of PCB (Printed Circuit Board). Magnetizing and measuring coils on every side of core enable measurements of both axis of tape. The results show, that differences in magnetic properties in two directions of tape caused by anisotropy are limited. Research opens possibility to develop two axis fluxgate sensors and miniature cores for power conversion devices.

Simulation and Optimization of Flexible Hooke Hinge

Flexible Flexible hinge is a typical flexible element in compliant mechanisms. Hooke hinge is a combination of the two revolute whose axis through the same point. It allows the two components have relative rotation of two degrees of freedom along the perpendicular axis. The distributed multi-reeds and large-deflection flexible Hooke hinge with the curve reed as the basic unit is analysed by finite element simulation, and is optimized in Multi-objective. The Hooke hinge after optimization lines with the basic rotation characteristics of Hooke hinge. It can provide the larger two-dimensional rotating schedule.It’s unilateral rotation angle can up to ±11.9 °, and the center drift and input coupling of rotation is small. So this flexible Hooke hinge is a new type of large deformation flexible Hook hinge which have excellent performance.

Growth of the dominant follicle and endometrial folding after administration of hCG in mares during oestrus

The purpose of the trial was evaluation of follicular growth and endometrial folding in mares after human chorionic gonadotropin (hCG) treatment in comparison with untreated mares during oestrus. In addition, the influence of follicle size at the time of hCG treatment on these parameters was evaluated. HCG (3000 IU) was administered intravenously in 17 mares bearing dominant follicles 35–40 mm in diameter (Group A) and in 13 mares with larger follicles (Group B). Ten mares with follicles ≥ 35 mm were untreated (Group C). Ultrasonographical examination of the mares continued in 6 h intervals until ovulation. Growth of the dominant follicle was faster in Group A than in Groups B and C (1.3 vs. 0.3 and 0.7 mm/6h, P < 0.05) but diameters of the preovulatory follicles were similar – 44, 48 and 44 mm in Groups A, B and C, respectively. Similarly, reduction of endometrial folding (on a three point scale) during observation was higher in Group A than in B and C (2.1 vs. 1.2 and 1.8, A : B P < 0.05) but endometrial folding values in the term before ovulation were not different (0.6, 0.9 and 0.6 in Groups A, B and C). A positive correlation between the speed of follicular growth and reduction of endometrial folding was found (r_s – 0.479, P = 0.003). Irregularity in follicle shape (the difference between the longest axis and its perpendicular axis) at the beginning of observation (3.3, 4.0 and 3.2 mm) was lower than before ovulation (7.4, 10.4 and 9.2 mm) in all groups (P < 0.01). The interval from the beginning of observation until ovulation was significantly shorter in Groups A and B versus C (37 and 31 vs. 103 h, P < 0.01). The results show that growth of dominant follicles after hCG is influenced by the size of the follicles at the time of treatment and correlates with reduction in endometrial folding as well as irregularity of follicle shape. Nevertheless, hCG treatment does not influence the size and shape of preovulatory follicles or endometrial folding immediately before ovulation.  

Improvement of Machining Accuracy in Micro Cylindrical Traverse Grinding

The elastic deformation of workpiece acted by grinding force is so large as to make the low machining efficiency and accuracy in the cylindrical grinding of micro parts of which the stiffness is extremely small because of their small diameter. In this study, the perpendicular axis type cylindrical traverse grinding is proposed for the manufacture of micro parts, and the undeformed chip shape in the grinding process is investigated comparing with that in the parallel axis type traverse grinding using generally for manufacture of over small-sized parts. The surface finish and the form accuracy of workpiece by the perpendicular axis type grinding are finer than those by the parallel axis type grinding with the developed micro cylindrical grinding machine.