Objective Evaluation of Drivability in Passenger Cars with Dual-Clutch Transmission: A Case Study of Static Gearshift Condition

This paper is aimed at the problem that the subjective drivability evaluation by experienced test drivers is limited in time efficiency and is of high cost and poor repeatability. In this article, an intelligent drivability objective evaluation tool (I-DOET) for passenger cars with dual-clutch transmission (DCT) is developed and verified by real vehicle testing. First, the signal denoising method and its key parameters, which are suitable for drivability evaluation, are selected based on analytic hierarchy process (AHP) and technique for order preference by similarity to ideal solution (TOPSIS). Besides, combined with the uncertainty characteristics of subjective judgment, a mathematical model of the objective drivability evaluation FARODE (fuzzy AHP-RS based on objective drivability evaluation) is proposed by using the fuzzy comprehensive assessment (FCA) method. The AHP and rough set (RS) method are used to calculate the subjective and objective weights of the drivability evaluation, respectively, and the proportion of subjective and objective weights is determined by the principle of minimum relative information entropy. The fuzzy matrix is built by membership function of the evaluation indexes. Finally, the static gearshift condition focused on by the subjective evaluation experts is taken as a case study. The predictability score is obtained by combining the drivability quantization lever vector, comprehensive weight, and fuzzy matrix. The experimental results indicate that the proposed method is applicable for objective drivability evaluation in passenger cars with DCT

Parameter Analysis on Torque Stabilization for the Eddy Current Brake: A Developed Model, Simulation, and Sensitive Analysis

Eddy current brake (ECB) is an attractive contactless brake whereas it suffers from braking torque attenuation when the rotating speed increases. To stabilize the ECB’s torque generation property, this paper introduces the concept of anti-magneto-motive force to develop the ECB model on the fundamental of magnetic circles. In the developed model, the eddy current demagnetization and the influence of temperature which make the braking torque attenuation are clearly presented. Using the developed model of ECB, the external and internal characteristics of the ECB are simulated through programming by MATLAB. To find the sensibility of the influences on ECB’s torque generation stability, the stability indexes are defined and followed by a sensibility analysis on the internal parameters of an ECB. Finally, this paper indicates that (i) the stability of ECB’s torque generating property could be enhanced by obtaining the optimal combination of “demagnetization speed point and the nominal maximum braking torque.” (ii) The most remarkable influencing factor on the shifting the demagnetization speed point of ECB was the thickness of the air-gap. (iii) The radius of pole shoe’s cross section area and the distance from the pole shoe center to the rotation center are both the most significant influences on the nominal maximum braking torque

Endovascular Thrombus Removal for Treating Post-Partum Iliofemoral Deep Vein Thrombosis: A Single-Centre Retrospective Cohort Study

Objective To evaluate the safety and efficacy of percutaneous thrombectomy for treating postpartum iliofemoral vein thrombosis. Methods A retrospective analysis was performed on patients with continuous postpartum acute symptomatic iliofemoral deep vein thrombosis who were treated in our center, including all patients who underwent pharmacomechanical thrombolysis (PMT) or only catheter-directed thrombolysis (CDT) (study group), and patients that received simple anticoagulation treatment (control group). We evaluated the incidence of lower extremity postthrombotic syndrome, recanalization rate of lower extremity veins, and complications in the study and control groups. Results Overall, 72 postpartum women were included in this study, including the PMT combined with CDT group (14 cases, 15 limbs), CDT alone group (26 cases, 27 limbs), and anticoagulant therapy alone group (32 cases, 34 limbs). The thrombectomy group completed the treatment with a technical success rate of 100%, and no serious bleeding complications occurred. The patency rate of lower limb veins in the thrombectomy group was 85.09 ± 16.51% after treatment and 82.60 ± 21.45% after 1 year. At the 1-year follow-up, the Villalta score in the study group was lower (1.90 ± 2.45 vs 8.50 ± 5.33, P  < .001), and the incidence of postthrombotic syndrome was significantly different between the groups (17.50% in the study group vs 68.75% in the anticoagulant group, P  < .001). Conclusions Lower extremity venous thrombectomy is a safe and effective treatment for postpartum iliofemoral venous thrombosis. It can improve the patency rate of lower extremity veins and reduce the incidence of postthrombotic syndrome compared with anticoagulation alone