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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <language>en-us</language>
    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
    </image>
    <item>
      <title>Risk ratio assessment of key parameters affecting main engine starting system failures on container ships</title>
      <link>https://trid.trb.org/View/2654137</link>
      <description><![CDATA[This paper analyzes failures associated with the main engine starting system, a component critical for ensuring operational continuity in maritime transport. The initial start-up process of the main engine plays a crucial role in both port maneuvers and navigational safety, and malfunctions during this process directly affect the safety and efficiency of ship operations.In this study, a Taguchi-based approach was applied to identify the factors affecting the occurrence of main engine starting system failures in container ships and to examine the effects of these factors on the frequency of failures. This approach allows for the statistically significant evaluation of interactions by optimizing the number of observations in multivariate systems. The results showed that the most important factor affecting the frequency of main engine starting system failures was the age of the ship (43.9 %), followed by the failure type of main engine starting system (21.0 %) and the ship's carrying capacity (2.4 %), respectively. The findings indicate that mechanical wear and system fatigue increase with the age of the ship; therefore, maintenance planning should be optimized according to the age factor.]]></description>
      <pubDate>Mon, 02 Feb 2026 09:31:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/2654137</guid>
    </item>
    <item>
      <title>A Novel Restart Strategy for Sensorless Rail Traction PMSM Drive With Continuous Short-Circuit Current</title>
      <link>https://trid.trb.org/View/2604056</link>
      <description><![CDATA[In rail traction, rotating restart is a common operational condition. For permanent magnet synchronous motors (PMSMs), obtaining accurate speed and rotor position prior to restart is crucial. In sensorless control system, the short-circuit current method is the most commonly used approach to obtain the initial position and speed. However, due to strict limitations on short-circuit time and interval time, this method is limited to a narrower speed range. This article proposes a novel restart strategy based on continuous short-circuit current for a wide speed range. In particular, it can handle the case that the amplitude of back electromotive force (EMF) exceeds the direct current (dc) bus voltage. Taking stator resistance into account, a mathematical derivation of the short-circuit current is performed. Using the continuous short-circuit current and a phase-locked loop (PLL), the initial motor speed and position are estimated. Furthermore, by applying the test zero-voltage pulses (ZVPs), the initial speed range is determined. The effectiveness of the proposed method is verified by simulation and experimental results.]]></description>
      <pubDate>Thu, 18 Dec 2025 10:56:12 GMT</pubDate>
      <guid>https://trid.trb.org/View/2604056</guid>
    </item>
    <item>
      <title>Restart Strategy for Sensorless Control of Permanent Magnet Synchronous Motor in Flux-Weakening Region</title>
      <link>https://trid.trb.org/View/2604032</link>
      <description><![CDATA[In railway transportation applications, especially during the transition through neutral sections, it is necessary for the motors to restart at specific speeds. For permanent magnet synchronous motors (PMSMs) operating in the flux-weakening region, this presents a significant challenge with sensorless control strategies due to back electromotive force (BEMF) and the lack of position and speed information. This article proposes a sensorless restart strategy that combines a single zero-voltage vector with a cascade extended state observer (CESO). During motor restart in the flux-weakening region, this method regulates the opening and closing of the contactor to mitigate the effects of uncontrolled rectification. The initial position and speed of the rotor are calculated using the current generated by a single zero-voltage vector, and fast convergence is achieved using a CESO to ensure the success of the restart process. The effectiveness of this method has been experimentally verified, demonstrating its potential to improve the reliability and efficiency of PMSMs in railway applications.]]></description>
      <pubDate>Mon, 15 Dec 2025 10:34:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/2604032</guid>
    </item>
    <item>
      <title>Research on flexible and controllable starting strategy for commercial vehicle diesel range extender</title>
      <link>https://trid.trb.org/View/2511221</link>
      <description><![CDATA[For range extender, engine starting conditions and boosting methods lead to varying oil film formation and pressure establishment durations, resulting in differences in optimal starting durations. This paper primarily addresses the control issue of range extender starting duration. Initially, it establishes and validates the dynamic model of the target range extender system, consisting of a four-cylinder diesel engine and a flywheel integrated starter generator (FISG). Subsequently, designing an adjustable and controllable target speed curve by polynomial splicing, and calibrates curve parameters by optimising vibration performance indicators. Based on the target speed curve, the motor torque is designed, with the torque corresponding to the speed primarily constructing the feedforward torque, supplemented by the feedback torque. Finally, the proposed starting control strategy is validated on the test bench, compared with the original strategy, and the impact of different control parameters on the starting control effect is analysed, confirming the effectiveness of the proposed strategy in achieving flexible and controllable starting times.]]></description>
      <pubDate>Tue, 25 Nov 2025 08:55:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/2511221</guid>
    </item>
    <item>
      <title>Optimal control strategy for vehicle starting coordination based on driver intention recognition</title>
      <link>https://trid.trb.org/View/2596689</link>
      <description><![CDATA[To enhance the starting performance of heavy-duty vehicles under different starting conditions, a vehicle starting coordinated optimal control method based on driver intention recognition is proposed. This method uses the Gaussian Mixture Model-Hidden Markov Model (GMM-HMM) for starting intention recognition, dividing the starting intentions into three categories: gentle start, normal start, and emergency start. The GMM-HMM starting intention recognition model is validated using real vehicle data. Based on the recognition results of driver intentions, a performance index function is defined as a weighted sum of smoke limit restriction time, 0–20 km/h acceleration time, and starting jerk. By assigning different weight coefficients, the allocation of requirements for starting power and comfort is achieved. Based on the principle of minimizing values, the coordinated control parameters (upshift speed and starting fuel quantity) are optimized, resulting in the optimal combination of coordinated control parameters under different starting intentions. This enables the optimal control of vehicle starting coordination based on the driver’s different starting intentions.]]></description>
      <pubDate>Wed, 24 Sep 2025 15:31:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/2596689</guid>
    </item>
    <item>
      <title>Enhancement of Two-Motor Hybrid Engine Start-up Vibration Performance by Motor Starting Torque Control Considering Power Plant Resonance</title>
      <link>https://trid.trb.org/View/2556922</link>
      <description><![CDATA[In order to suppress the variation in body vibration at the start-up of a compact two-motor hybrid vehicle, this study focused on the coupling between the initial frequency of the input shaft torque fluctuation due to the forcing force, in addition to the torsional damper resonance and power plant rigid body resonance, which are the causes of the vibration. By increasing the starting torque rise, these coupling effects were avoided, power plant vibration was reduced, and the variation in body vibration was reduced to the same level as the target for a mid-size vehicle.]]></description>
      <pubDate>Thu, 26 Jun 2025 16:12:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/2556922</guid>
    </item>
    <item>
      <title>Time-Optimal Coordination Gear-Shifting Control With a Rotational Angle Difference Estimation and Alignment Algorithm in the Vehicle-Start Condition</title>
      <link>https://trid.trb.org/View/2512043</link>
      <description><![CDATA[Multigear transmission in electric vehicles (EVs) can help the drive motor operate on high-efficiency working points by shifting gears. However, big jerks and long power interruption are two crucial issues during gear-shifting process, especially in the vehicle-start condition (VSC) when the rotational angle difference between the sleeve and gear ring is unknown. The authors focus on a non-synchronizer electric-driven mechanical transmission (NEMT) system, which removes the complex clutch system and synchronizer. A novel gear-shifting control strategy with a rotational angle difference estimation algorithm (RADEA) and a time-optimal alignment and cooperative control strategy is proposed to reduce the time and jerks. First, the mechanical and electric structures of the NEMT are presented. Then, an experimentally validated gear-shifting dynamic model is developed. After that, a RADEA and an angle alignment algorithm are designed to reduce jerks by estimating and aligning the rotational angle difference. The time-optimal coordination control law for the shift motor is proposed to save time. Finally, a state-feedback model tracking control strategy with the time-optimal control law as the feed-forward is designed and validated on the test bench. Compared to the traditional constant-force control algorithm, the proposed strategy is more effective, taking 15 ms less time and producing only 30% of jerks.]]></description>
      <pubDate>Tue, 27 May 2025 09:34:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/2512043</guid>
    </item>
    <item>
      <title>A Restart Method of Permanent Magnet Synchronous Machine Sensorless Drives With a Single DC-Bus Current Sensor</title>
      <link>https://trid.trb.org/View/2511792</link>
      <description><![CDATA[When restarting a permanent magnet synchronous machine (PMSM) sensorless drive at an unknown initial speed, the initial position and speed must be estimated before applying pulsewidth modulation (PWM) signals to the inverter. Then, a proper initial voltage vector with the right direction and magnitude can be generated to avoid an inrush current that may impair power switches. Nevertheless, a PMSM sensorless drive with a single dc-bus current sensor is a challenging work and has not been solved thoroughly. Because the conventional zero-voltage injection method cannot work due to the unmeasured phase current in a single dc-bus current sensor drive. This article proposes a novel restart method by applying three pairs of active-voltage vectors during the flying state. Six dc-bus currents are sampled sequentially, and phase currents can be reconstructed. Then, the initial position and speed can be estimated continuously using a phase-locked loop (PLL) based on the phase current angle. Furthermore, the estimation errors due to the sequential samplings and inductance saliency are analyzed and compensated. The effectiveness of the proposed method is verified in two PMSM sensorless drives. A smooth and fast transition from the flying state to sensorless closed-loop control can be implemented by avoiding inrush currents, which improves the reliability of PMSM sensorless drives.]]></description>
      <pubDate>Wed, 23 Apr 2025 11:54:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/2511792</guid>
    </item>
    <item>
      <title>Nudging drivers: The influence of innovative green-phase forewarning systems on drivers' start-up behavior at signalized intersections</title>
      <link>https://trid.trb.org/View/2480448</link>
      <description><![CDATA[Traffic congestion, especially at signalized intersections along urban arterials, poses a global challenge affecting travel efficiency, mental health, and air quality. This study investigates the effectiveness of innovative forewarning systems in reducing start-up lost time at signalized intersections. In this regard, four different forewarning systems were tested and compared with the untreated control condition in a driving simulator experiment inviting 61 participants with a valid driving license. All the tested conditions were tested for two different waiting times, i.e., 20 s and 60 s to evaluate their impact on reaction times, start-up lost time, and early start-up behaviors. The results of the study demonstrated that among the tested conditions, the clock-based VMS with a 2 s (VMS_2s) warning proved to be the most effective in significantly reducing start-up delays by 21.2 %. In addition, VMS_2s and R_yellow; the condition where the yellow signal was displayed simultaneously with the red signal during the last two seconds, effectively reduced drivers' reaction times at the onset of green signal by 53.5 % and 62.4 %, respectively. Moreover, the results did not reveal any instance of risky early start-up behaviors, such as red light running violations. Based on the study findings, the VMS_2s and R_yellow conditions are suggested for further evaluation and potential real-world implementation to improve drivers' start-up behavior at signalized intersections.]]></description>
      <pubDate>Tue, 18 Feb 2025 10:56:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/2480448</guid>
    </item>
    <item>
      <title>Analysis of vibration responses in a large airport ground transportation centre caused by maglev and subway trains</title>
      <link>https://trid.trb.org/View/2454753</link>
      <description><![CDATA[This study aims to assess the vibration response of the ground transportation centre (GTC) at an airport integrated transportation hub during the starting and braking processes of underground maglev and subway trains. In this work, the authors considered the actual motion states of trains entering and exiting the GTC and calculated the traction characteristics of maglev and subway trains. On this basis, the vertical coupling vibration models for a medium- and low-speed maglev train-guideway and a subway train-floating slab track considering variable-speed motion, as well as the vehicle longitudinal motion models, were established, and the vertical and longitudinal fastener forces of the tracks were obtained accordingly. Finally, based on the two-step analysis method, the vertical and longitudinal fastener forces were simultaneously applied to the track–GTC–soil finite element model to evaluate the structural vibrations induced by maglev and subway trains. The results show that the amplitude of the vertical fastener force is an order of magnitude greater than that of the longitudinal fastener force, and the amplitude of the vertical fastener force caused by subway trains is greater than that caused by maglev trains. The starting process of both maglev trains and subway trains results in a greater vertical vibration response of the GTC than the braking process, with the impact of subway trains being greater than that of maglev trains. Within the same area, the vertical vibration level observed at structural column observation points is lower than that at slab observation points. When maglev trains and subway trains start simultaneously, the vibration level response at some points exceeds the specified limit of 75 dB.]]></description>
      <pubDate>Wed, 11 Dec 2024 10:39:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/2454753</guid>
    </item>
    <item>
      <title>Particulate Matter Emission During Start-up and Transient Operation of a Spark-Ignition Engine (2): Effect of Speed, Load, and Real-World Driving Cycles</title>
      <link>https://trid.trb.org/View/1786912</link>
      <description><![CDATA[Previous research into Particulate Matter (PM) emissions from a spark-ignition engine has shown that the main factor determining the how PM emissions respond to transient engine operating conditions is the effect of those conditions on intake port processes such as fuel evaporation. The current research extends the PM emissions data base by examining the effect of transient load and speed operating conditions, as well as engine start-up and shut-down. In addition, PM emissions are examined during “real-world” driving conditions - specifically, the Federal Test Procedure. Unlike the previous work, which was performed on an engine test stand with no exhaust gas recirculation and with a non-production engine controller, the current tests are performed on a fully-functional, production vehicle operated on a chassis dynamometer to better examine real world emissions. PM emissions prior to and after dilution are examined, and the results are discussed in the context of a previously developed PM formation and emission model. The results show that the greatest increases in PM emissions come directly after start-up, and when load is increased - either when the load is increased at constant speed, or when the vehicle accelerator is depressed to change speed while maintaining nominally constant intake pressure. Engine shut-down can cause a brief, small peak in PM emissions, for reasons that will be discussed.]]></description>
      <pubDate>Thu, 07 Nov 2024 11:52:24 GMT</pubDate>
      <guid>https://trid.trb.org/View/1786912</guid>
    </item>
    <item>
      <title>A new real-time optimal energy management strategy for range extended electric vehicles considering battery degradation and engine start-up</title>
      <link>https://trid.trb.org/View/2410567</link>
      <description><![CDATA[Range extended electric vehicles (REEVs) offer a solution to the limited range of pure electric vehicles by incorporating an additional energy source. Effectively managing the output power among these energy sources is the key to reduce operating cost. To enhance the economy of REEVs, this paper proposes a multi-objective optimal energy management strategy (MOEMS) that considers battery degradation. The powertrain of the REEV is comprehensively modeled by integrating the efficiency of the range extender, battery, and driving motor. MOEMS is designed to instantaneously minimize the total operating cost of the vehicle, including factors such as fuel consumption, electricity consumption, and battery degradation. To minimize the frequency of engine starts and stops, the cost associated with engine startup is integrated into the objective function. Two control coefficients are introduced into the objective function to regulate the battery state of charge. Additionally, another coefficient is employed to restrict variations of engine output power, thereby avoiding significant fluctuations of engine load. Simulation results show that compared to the adaptive equivalent consumption minimization strategy (AECMS) and rule-based energy management strategy (REMS), the total cost of MOEMS is reduced by 9.1% and 32.3% in Worldwide Harmonized Light Vehicles Test Cycle (WLTC) driving cycles, and by 7.9% and 31.7% in China Light Vehicle Test Cycle (CLTC) driving cycles.]]></description>
      <pubDate>Sun, 18 Aug 2024 11:28:34 GMT</pubDate>
      <guid>https://trid.trb.org/View/2410567</guid>
    </item>
    <item>
      <title>Fuzzy Control of AMT Clutch Engagement during the Vehicle Starting</title>
      <link>https://trid.trb.org/View/2203680</link>
      <description><![CDATA[Clutch engagement process of automatic mechanical transmission is investigated during the process of starting the vehicle. The kinetics of clutch engagement is analyzed and the dynamical equation was deduced. Clutch engagement speed is changed by body load and road condition. A method of correcting the driving intention is proposed to adopt quality of vehicle conversion coefficient. The more fuzzy input parameters arouse the more control rules and increase computational load of ECU; the method of double fuzzy controller is brought forward to control speed of clutch engagement. Simulation of the model is carried out in Matlab/Simulink. Results show that fuzzy control rules with quality of vehicle conversion coefficient can effectively improve clutch engagement process.]]></description>
      <pubDate>Thu, 18 Jul 2024 10:48:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/2203680</guid>
    </item>
    <item>
      <title>A Hybrid Sensorless Starting Strategy for SRM With Fault-Tolerant Capability</title>
      <link>https://trid.trb.org/View/2201130</link>
      <description><![CDATA[The electromagnetic characteristics of the switched reluctance motors (SRMs) appear highly nonlinear due to the high phase current in the starting stage. Thus, the key issue of developing a reliable sensorless starting strategy is to seek an effective way to avoid the saturation effects on position estimation. In this article, a hybrid sensorless starting strategy with fault-tolerant capability is proposed. First, an unsaturated inductance restructure-based inductance vector coordinate transformation (UIR-IVCT) method is proposed for accurate initial positioning at standstill and continuous position estimation in the starting operation. Second, an incremental inductance partition (IIP) method with a bottom incremental inductance threshold is proposed for position pulse indirect measurement and fault-tolerant position estimation under phase lacking faults. These two methods are combined to ensure continuous position estimation under normal operation and fault-tolerant position estimation under one or two phases lacking cases. Thus, the proposed hybrid sensorless strategy can highly improve the overall reliability of the sensorless starting process. Furthermore, the proposed method is easy for implementation without complex initial data measurement, complicated parameter modeling, and heavy memory space. Detailed analysis and experimental results based on a 12/8 structure SRM prototype machine are provided for verification.]]></description>
      <pubDate>Sun, 30 Jun 2024 16:02:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/2201130</guid>
    </item>
    <item>
      <title>Research on the Power-on and Power-Off Control and Propulsion Control Method in Hybrid and Electric Vehicles</title>
      <link>https://trid.trb.org/View/2367276</link>
      <description><![CDATA[The traditional car's power-up and power-down sequence is only designed for 12V low-voltage system, which is harmless to human body and does not involve the functional safety of the vehicle. The existing power-up and power-down technologies for high-voltage systems (above 220V) are mostly designed for pure electric vehicles, plug-in hybrid electric vehicle, and non-plug-in hybrid electric vehicle. There is no one process that is applicable to EV, PHEV, and HEV, and it rarely involves the power-up and power-down sequence of one-key start and remote start, and for the power-down delay problem when there is battery cooling and motor cooling request, the battery failure, DCDC failure, collision, low battery SOC, the active power-down sequence problem when the external charging gun is connected, and the sequence problem when the controller resets the fault. The seven states of the power-up and power-down sequence control defined in this paper are: state 1 is the initial state, state 2 is the CPSR relay disconnection, state 3: the CPSR relay is closed, state 4: the high-voltage relay is closed, state 5: the DCDC is closed, state 6: the initial state of the collision, and state 7: the collision state. Compared with other technologies, the timing definition of the collision state is added. The control logic modeling and simulation analysis of the vehicle's power-up, power-down and motor management system faults are conducted by Simulink, and the verification is carried out under the real vehicle test. The test results show that the power on and the power off treatment accord with the control logic, the failure power off treatment ensures the high voltage safety, and the power on and off control logic is more conducive to the vehicle energy control.]]></description>
      <pubDate>Tue, 07 May 2024 09:44:36 GMT</pubDate>
      <guid>https://trid.trb.org/View/2367276</guid>
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