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In hobbing motion chamfering of cylindrical gear tooth profiles, the tool parameters and mounting position parameters of the chamfering tool directly affect the results. In this paper, the co-optimization method of multiparameters is proposed. Considering the consistency and symmetry of the chamfering result, a multiparameter co-optimization model is established. The improved non-dominated sorting genetic algorithms-II (INSGA-II) is proposed for the optimization effect of the model. The optimization and determination parameter combinations are performed using INSGA-II and Fuzzy C-means_Grey Relational Projection (FCM_GRP). Finally, the optimized parameter combinations are used to calculate the tool rake face profile, and the local curve superposition improves the uneven chamfering at the transition arc. The proposed method’s effectiveness is verified based on the tooth profile chamfering simulation results.

The assembly of large and complex products such as cars, trucks, and white goods typically involves a huge amount of production resources such as workers, pieces of equipment, and layout areas. In this context, multi-manned workstations commonly characterize these assembly lines. The simultaneous operators’ activity in the same assembly station suggests considering compatibility/incompatibility between the different mounting positions, equipment sharing, and worker cooperation. The management of all these aspects significantly increases the balancing problem complexity due to the determination of the start/end times of each task. This paper proposes a new mixed-integer programming model to simultaneously optimize the line efficiency, the line length, and the workload smoothness. A customized procedure based on a simulated annealing algorithm is developed to effectively solve this problem. The aforementioned procedure is applied to the balancing of the real assembly line of European sports car manufacturers distinguished by 665 tasks and numerous synchronization constraints. The experimental results present remarkable performances obtained by the proposed procedure both in terms of solution quality and computation time. The proposed approach is the practical reference for efficient multi-manned assembly line design, task assignment, equipment allocation, and mounting position management in the considered industrial fields.

The effect of Gurney flap height and mounting position on the head coefficient of a centrifugal fan at different Reynolds numbers is investigated experimentally. Quarter round Gurney flap of 1.0, 1.5, 2.0 and 2.5 mm height is mounted at three different positions, S=1.00 (impeller tip), S=0.95 and S=0.90 on the pressure surface of the impeller blade tip. Performance tests are carried out on the centrifugal fan at five Reynolds numbers corresponding to five rotational speeds of 1100, 1500, 2000, 2500 and 2900 rpm respectively. From the performance curves it is found that the fan head coefficient increases significantly with Gurney flaps at low Reynolds numbers and increases marginally at high Reynolds numbers. Effect of Reynolds number on the head coefficient is considerable for the baseline fan and found to be negligible for the fan with Gurney flaps, for all combinations of Gurney flap mounting position and height. The head coefficient of the fan improves as Gurney flap height increases but the improvement is marginal after certain height of Gurney flap. The head coefficient of the fan deteriorates when Gurney flap is mounted away from the impeller blade tip.

This paper proposes optimization of a mounting position and angle for vehicle RKE antennas. To take into consideration the platform effect that degrades the radiation characteristic of the antenna, both interior and exterior vehicle structures are re-modeled as piece-wise mesh elements in a full-wave electromagnetic (EM) simulator. The optimum placement is found by evaluating radiation characteristics for all possible placements, and its average gain is improved by 4.7 dB, while the minimum gain is increased by 8.4 dB, compared to the conventional placement. The results demonstrate that the proposed method is suitable for maximizing the reading distance of the antenna by minimizing the platform effect.

This contribution is concerned with joint angle calculation based on inertial measurement data in the context of human motion analysis. Unlike most robotic devices, the human body lacks even surfaces and right angles. Therefore, we focus on methods that avoid assuming certain orientations in which the sensors are mounted with respect to the body segments. After a review of available methods that may cope with this challenge, we present a set of new methods for: (1) joint axis and position identification; and (2) flexion/extension joint angle measurement. In particular, we propose methods that use only gyroscopes and accelerometers and, therefore, do not rely on a homogeneous magnetic field. We provide results from gait trials of a transfemoral amputee in which we compare the inertial measurement unit (IMU)-based methods to an optical 3D motion capture system. Unlike most authors, we place the optical markers on anatomical landmarks instead of attaching them to the IMUs. Root mean square errors of the knee flexion/extension angles are found to be less than 1° on the prosthesis and about 3° on the human leg. For the plantar/dorsiflexion of the ankle, both deviations are about 1°.

With mounting data on its accuracy and prognostic value, cardiovascular magnetic resonance (CMR) is becoming an increasingly important diagnostic tool with growing utility in clinical routine. Given its versatility and wide range of quantitative parameters, however, agreement on specific standards for the interpretation and post-processing of CMR studies is required to ensure consistent quality and reproducibility of CMR reports. This document addresses this need by providing consensus recommendations developed by the Task Force for Post Processing of the Society for Cardiovascular MR (SCMR). The aim of the task force is to recommend requirements and standards for image interpretation and post processing enabling qualitative and quantitative evaluation of CMR images. Furthermore, pitfalls of CMR image analysis are discussed where appropriate.

ObjectivesThis clinical study aimed to compare the performance of various virtual articulator (VA) mounting procedures in the participants’ natural head position (NHP).Materials and methodsFourteen participants with acceptable dentitions and jaw relationships were recruited in this study registered in the Clinical Trials Registry (#NCT05512455; August 2022). A virtual facebow was designed for virtual mounting and hinge axis measurement. Intraoral scans were obtained, and landmarks were placed on each participant’s face to register the horizontal plane in NHP. Six virtual mounting procedures were performed for each participant. The average facebow group (AFG) used an indirect digital procedure by using the average facebow record. The average mounting group (AMG) aligned virtual arch models to VA’s average occlusal plane. The smartphone facial scan group (SFG) and professional facial scan group (PFG) used facial scan images with Beyron points and horizontal landmarks, respectively. The cone-beam computed tomography (CBCT) scan group (CTG) used the condyle medial pole, and horizontal landmarks were applied. The kinematic facebow group (KFG) served as the control group, and a direct digital procedure was applied using a kinematic digital facebow and the 3D skull model. Deviations of the reference plane and the hinge axis between the KFG and other groups were calculated. The inter-observer variability in virtual mounting software operation was then evaluated using the interclass correlation coefficient (ICC) test.ResultsIn virtual condylar center deviations, the CTG had the lowest condylar deviations. The AFG showed larger condylar deviations than PFG, SFG, and CTG. There was no statistically significant difference between the AFG and the AMG and between the PFG and the SFG. In reference plane deviations, the AMG showed the largest angular deviation (8.23 ± 3.29°), and the AFG was 3.89 ± 2.25°. The angular deviations of PFG, SFG, and CTG were very small (means of each group < 1.00°), and there was no significant difference among them. There was no significant difference between the researchers, and the ICC test showed moderate to excellent reliability for the virtual condylar center and good to excellent reliability for the reference plane in the operation of the virtual mounting software.ConclusionsCBCT scan provided the lowest hinge axis deviation in virtual mounting compared to average mounting, facebow record, and facial scans. The performance of the smartphone facial scanner in virtual mounting was similar to that of the professional facial scanner. Direct virtual mounting procedures using horizontal landmarks in NHP accurately recorded the horizontal plane.Clinical relevanceDirect digital procedures can be reliably used for virtual articulator mounting. The use of a smartphone facial scanner provides a suitable and radiation-free option for clinicians.

Multi-source fusion constitutes a research focus in the navigation domain. This article focuses on the online estimation of the mounting angles between the body frame and vehicle frame within low-cost embedded vehicle navigation modules and the lever arm between the global satellite navigation system (GNSS) antenna/odometer and the inertial measurement unit (IMU). An online mounting angle error estimation algorithm, using odometers and IMU speeds, has been developed to estimate the angle errors while vehicles are in motion. At the same time, an online estimation algorithm model for the GNSS antenna lever arm and odometer lever arm was constructed. These two types of lever arms are used as the estimated states, and then Kalman filters are used to estimate them. The algorithm can simultaneously estimate the IMU mounting angle error, GNSS antenna arm, and odometer arm online. The experimental outcomes demonstrate that the lever arm estimation algorithm presented herein is effective for tactical and MEMS-level inertial navigation, with an estimation error of less than 2 cm. Meanwhile, the proposed online estimation of the mounting angle algorithm has an accuracy comparable to that of the post-processing algorithm. After making up the mounting angle and lever arm, we found that the position and speed precision of the multi-source fusion navigation systems were significantly improved. The results indicate that the proposed online estimation of mounting angle error and lever arm algorithm are effective and may promote the practical and widespread application of integrated navigation systems in vehicles. It solves the shortcomings of traditional methods, including the cumbersome and inaccurate manual measurement of the lever arm. It provides a technical solution for developing a more accurate and convenient low-cost vehicle navigation module.

This research aims to study the vibration analysis in the camera holder of Auto Core Adhesion Mounting machine that used in hard disk drive industry for attaching slider onto suspension (HGA). The base excitation of the machine occurs when manufacturing speed increases. This results in position error while image processing. The image processing finds the referent hole position of suspension before attachment slider onto suspension process, the impact of vibration is impact to 3rd camera holder at 43 Hz and 100 Hz. Then four models for the analysis of vibration signal and isolators selected for reducing vibration of camera holder. The 4th model isolator shown best performance to reduce vibration and improve the efficiency of image processing.

The digital Hall-effect sensors are widely used for the rotor position estimation in permanent magnet synchronous motors (PMSMs) for light electric vehicles. Many scholars have discovered that the inevitable misalignment in the sensor mounting due to technical limitations has a negative impact on motor torque and vibration, but the characteristics of the torque ripple and torsional vibration remain unsolved. The analysis of the torque ripple and torsional vibration considering Hall mounting errors is carried out in this work, which makes the vibration-based diagnosis of Hall mounting errors possible and lays a foundation for improving the torque and vibration quality of electric motors. The harmonic characteristic analysis of PMSMs is firstly carried out, which lays a foundation for analyzing the phase current caused by the rotor position error. Subsequently, the order characteristics of the phase current and motor torque considering the rotor position error are derived. Then, the rotor position error caused by Hall mounting errors is analyzed, and the consequential order characteristics of the phase current and torque ripple are derived. Finally, simulated and experimental results are presented to validate the theoretical analysis. It is found that the rotor position error will induce voltage harmonics in PMSMs, resulting in the corresponding current harmonics and torque ripples. The rotor position error caused by Hall mounting errors contains dc component and even order harmonics, which will mainly produce new even order torque ripple and torsional vibration.