An improved startup mode using clutch coupling for in-wheel electric vehicle drives

By introducing a new type of clutch into the driveline system of an in-wheel drive electric vehicle, a flexible connection has been developed to replace the rigid one between the hub and the motor. The driving motor can realize variable idling, unlike the internal combustion engine, which needs a minimum rotational speed. This paper proposes a new startup method that utilizes the initial kinetic energy of the motor to achieve a smooth and fast acceleration of the wheel speed from zero to the expected motor speed. First, the powertrain system, including the driving motor, the clutch and the vehicle resistance, is modelled. Second, factors influencing the starting current and the jerk level during the starting process are investigated. In consequence, the idle speed can be interpreted as a tunable variable that determines the tradeoff between the torque capacity and the jerk level. Finally, simulation and experiments on a laboratory test rig are performed. The results validate that the proposed variable-idle speed control strategy has a lower jerk level and lower starting current when compared with those using a direct start under the same load condition

Spatial and temporal variation of north-west pacific tropical cyclone under the background of upper ocean warming

879-885Under the background of global warming, the activities of north-west pacific (NWP) tropical cyclones (TCs) are undergoing significant changes. The TC frequencies have been characterized by an initial slow increase followed by a rapid increase and then a decrease, the past 33 years. During the 21st century, the TC frequency of the NWP has clearly decreased. However, the three TC origin types in the NWP have experienced different types of changes. The TC frequencies of origin 1 (10°~22°N,110°~120°E) and origin 2 (8°~20°N,125°~145°E) are both increasing, but the TC frequency of origin 3 (5°~20°N,145°~155°E) is decreasing. Under the background of upper ocean warming, the average TC duration has shown a decreasing trend (-0.27d/10a), while the TC mean and maximum intensity has increased (0.93 m/s/10a and 1.57 m/s/10a, respectively). Therefore, the potential threats of TC activities to NWP coastal countries are likely to intensify. The changes in the thermal state of the upper ocean have many effects on TC activities. Sea surface temperature is not the main factor affecting the frequency of TCs. However, the response of TCs to the upper ocean heat content is obvious

Research on torque compensation with optimal pedal throttle for direct-drive electric vehicle start-up

Originalna kruta veza između motora i glavine zamijenjena je fleksibilnom uporabom spojke za povezivanje pogonskog i gonjenog vratila sustava prijenosa. U radu se zatim predstavlja odvojeni proces pokretanja i opterećenja motora na osnovu kojega se analizira shema reguliranja rada motora u praznom hodu. Fokusiranjem na probleme koordinacije povećanog kapaciteta zakretnog momenta i smanjenja trzaja automobila samo regulacijom rada motora u praznom hodu, predlaže se poboljšano rješenje kompenzacije zakretnog momenta podešavanjem napona rotora dok se spojka aktivira gonjenom stranom. Nadalje, ispituje se i optimizira metoda za označavanje napona zakretnog momenta s ciljem stvaranja balansa između traženog prijenosnog mehanizma zakretnog momenta i jačine trzaja tijekom pokretanja vozila. Konačno, eksperimentima je demonstriran učinkovito poboljšani učinak zakretnog momenta pogonskog motora kod pokretanja vozila u svrhu povećane udobnosti.The original rigid connection between the motor and the hub is replaced with a flexible one using the clutch to connect the driving and driven sides of the driveline system. Then the paper proposes a separable process of motor start-up and load operation, based on which the scheme of idle speed control is studied. Focusing on the contradiction between the extended torque capacity and the reduced vehicle jerk merely by tuning the idle speeds, an improved solution is proposed for toque compensation by throttle adjustment during the clutch engagement. Furthermore, the method for tracking the armature voltage of the driving motor is investigated and optimized, aiming at the balance between the demanded transmitted torque and the jerk level during the starting process. Finally, effectively enhanced torque capacity of the driving motor for the vehicle start-up on the premise of the improved comfort level has been demonstrated by experiments

Analysis of Eccentrically Loaded FRP Partially Wrapped Reinforced Concrete Columns Subjected to Combined Environmental Erosion

The Behavior of Eccentrically Loaded Fiber Reinforced Polymer (FRP) Partially Wrapped Reinforced Concrete (RC) Columns under Combined Environmental Erosion Was Investigated in This Paper. Circular RC Columns Were Firstly Subjected to Chloride Erosion Where the Target Corrosion Degree (0, 10 %, and 20 %) is Obtained with Externally Applied Current. This Was Then Followed by Partially Strengthening with 2-Ply of Glass Fiber Reinforced Polymer (GFRP) Strips as Well as 50 Freeze–thaw Cycles. Series of Eccentric Compression Tests Were Conducted with Ranging Eccentricities of 0, 5 Mm, 10 Mm, and 15 Mm. for Comparison, the Carbon Fiber Reinforced Polymer (CFRP) Partially Strengthened Columns with the Corrosion Degree of 10 % and Subjected to 50 Freeze–thaw Cycles Were Also Eccentrically Loaded with an Eccentricity of 10 Mm. Results Showed that with Increasing Corrosion Degree, the Bearing Capacity of GFRP Strengthened Column Showed a 2-Stage Behavior (Firstly Increased and Then Decreased), Which May Be Caused by the Confinement Reduction of FRP on Columns Due to Severe Environmental Erosion. under Small Eccentric Loading, the CFRP Strengthened RC Columns Showed Better Compressive Behavior Than that of GFRP Strengthened RC Columns. based on the Stress–strain Relationship of Constituent Materials, a Simplified Analytical Model Considered the Effects of Chloride and Freeze–thaw Erosion Was Put Forward to Predict the Bearing Capacity of FRP Partially Wrapped RC Column under Eccentric Loading

One-pot synthesis of 2-alkyl cycloketones on bifunctional Pd/ZrO₂ catalyst

2-Alkyl cycloketones are essential chemicals and intermediates for synthetic perfumes and pesticides, which are conventionally produced by multistep process including aldol condensation, separation and hydrogenation. In present work, a batch one-pot cascade approach using aldehydes and cycloketones as the raw materials, and a bifunctional Pd/ZrO2 catalyst was developed for the synthesis of 2-alkyl cycloketones, e.g., cyclohexanone and cycloheptanone. Very high aldehydes (except for paraldehyde with large steric hindrance) conversion and high yields for 2-alkyl cycloketones (e.g., 99 % of conversion for n-butanal and 76 wt.% of yield for 2-butyl cyclohexanone) were obtained at mild temperature of 140 °C. After 10 cycles of reuse, Pd/ZrO2 catalyst showed slight deactivation (ca. 5 % conversion and 10 % yield losses), due to the coke on the catalyst. However, the performance of the catalyst was completely recovered after an oxidative regeneration

Robot-assisted percutaneous screw fixation in the treatment of navicular fracture

BackgroundLong recovery time, large scar, postoperative swelling and pain are possible side effects of open reduction internal fixation (ORIF) for tarsal navicular fractures. Early exercise instruction is made possible by the use of an intraoperative robot-assisted percutaneous invasive closed reduction internal fixation. The goal of the trial was to determine whether percutaneous screw internal fixation with robot assistance might be used to treat navicular fractures.Methods27 patients with navicular fractures had surgical treatment between June 2019 and December 2021. Of those, 20 instances were treated with ORIF, while 7 cases had robot-assisted percutaneous screw internal fixation. At the final follow-up, the American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score and the visual analogue scale (VAS) score were compared to determine outcomes and function.ResultsFollow-up was obtained in all 27 patients after surgery, with a mean follow-up time of 21.81 months, ranging from 15 to 29 months . In the 7 instances of robot-assisted group, percutaneous guide wire insertion and screw placement only needed one attempt and the depth and position of the implant were both satisfactory. In the ORIF group, there were two patients who sustained cutaneous nerve injuries. The AOFAS score and the VAS score of the group receiving robot-assisted navigation percutaneous screw fixation were 92.25 ± 2.22 and 0.75 ± 0.25 respectively at the last follow-up, while 82.25 ± 7.15 and 0.50 ± 0.29 were the respective values for the ORIF group.ConclusionIntraoperative robot-assisted percutaneous closed reduction internal fixation for tarsal navicular fractures can accomplish exact localization of fracture site, reduce soft tissue damage and operative time. According to current view, this method offers fewer complications, a faster recovery after surgery, and more patient satisfaction

Lateral approach for insertional Achilles tendinitis with Haglund deformity

ObjectiveThe study aims to investigate the functional outcome of the lateral approach for insertional Achilles tendinitis (IAT) with Haglund deformity.MethodsFrom January 2016 to September 2019, 14 cases of IAT with Haglund deformity that resisted conservative treatment received surgery in our department. A lateral approach was used to debride the bony and soft tissue and reattach the insertion of the Achilles tendon. The Visual Analog Scale (VAS), American Orthopedic Foot and Ankle Score (AOFAS), and Victorian Institute of Sport Tendon Study Group-Achilles Tendinopathy score (VISA-A) were used to evaluate clinical outcomes.ResultThe mean patient age was 39.57 years at the time of surgery. The mean follow-up was 14.74 months. The mean VAS score significantly decreased from 4.86 ± 0.86 preoperatively to 1.21 ± 1.58 postoperatively (P < 0.001). The mean AOFAS score significantly improved from 66.64 ± 6.23 preoperatively to 90.21 ± 11.50 postoperatively (P < 0.001). The mean preoperative and the last follow-up VISA-A were 66 (range 56.75–69.25) and 86 (range 75.75–97.00) points, respectively (P < 0.05).ConclusionThe lateral approach was effective and safe for IAT with Haglund deformity. Moreover, the mid-term functional outcome was promising.Level of Clinical EvidenceI

Effect of HAP decomposition on the corrosion behavior of Ti-HAP biocomposites

Ti-HAP biocomposites are gained attention for combining the attractive properties of Ti and hydroxyapatite (HAP). However, the decomposition of HAP at elevated processing temperatures is a major concern since it can lead to structural flaws and may deteriorate the corrosion resistance of Ti. The present study aims to investigate the corrosion behavior of Ti-HAP composite processed by powder metallurgy by performing potentiodynamic polarization and electrochemical impedance spectroscopy in 0.9wt% NaCl solution at body temperature. Results show that the presence of Ti lowers the HAP decomposition temperatures resulting in the formation of HAP-depleted zones acting as electrochemically active sites, decreasing the corrosion resistance.This study was supported by the Foundation for Science andTechnology (FCT), Portugal with the reference projects UID/EEA/04436/2013, EXCL/EMS-TEC/0460/2012, and M-ERA-NET/0001/2015, as well, by FEDER funds through the COMPETE 2020–Programa Operacional Competitividade eInternacionalização (POCI) with the reference project POCI-01-0145-FEDER-006941. The authors would also like toacknowledge Prof. Ana Senos (University of Aveiro) andProf. José Carlos Teixeira (University of Minho) for theprovision of the characterization facilities