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Semi-trailers are widely used in highway freight transportation because of their large payload capacity and high transport efficiency. However, structural characteristics such as a high center of gravity (CG), heavy loads, and the dynamic coupling between the tractor and trailer make them prone to yaw instability and rollover under complex conditions. To solve these problems, this article proposes a hierarchical stability control architecture for semi-trailers based on the joint estimation of equivalent parameters. First, a six-degree-of-freedom (6-DOF) theoretical dynamic model is established. This model includes the lateral, yaw, and roll motions of both the tractor and trailer to provide desired reference states. Second, a parameter estimation method combining a genetic algorithm (GA) with a forgetting-factor recursive least squares (RLS) algorithm is designed. It dynamically identifies eight unknown equivalent parameters, specifically the tire cornering stiffness and suspension damping. Next, a hierarchical controller is developed. The upper layer uses model predictive control (MPC) to calculate the required additional yaw moments, while the lower layer allocates these moments through quadratic programming (QP) based on vehicle steering characteristics. Co-simulation results, evaluated using error metrics that compare control outputs directly against TruckSim reference outputs, show that the fusion GA-RLS method offers better accuracy and adaptability than a standalone GA. Furthermore, the stability controller prevents rollover in high-speed maneuvers and reduces peak state indicators by over 41.2% in low-speed scenarios. Robustness tests also confirm its effectiveness under low-adhesion road conditions and heavy payloads. Compared with a conventional fixed-parameter MPC, the proposed adaptive architecture improves key stability indicators by 19% to 25%, effectively enhancing the dynamic safety of semi-trailers.
Song, DafengNi, LixinDuan, ChaoshengZeng, Xiaohua
This SAE Recommended Practice describes chemical analysis, hardness, microstructure, and physical characteristic requirements for low carbon cast steel shot to be used for shot peening or blast cleaning operations.
Surface Enhancement Committee
This SAE Recommended Practice describes the testing procedures required to evaluate the integrity of a ground ambulance-based patient litter, litter retention system, and patient restraint when exposed to a frontal, side or rear impact. Its purpose is to provide litter manufacturers, ambulance builders, and end-users with testing procedures and, where appropriate, acceptance criteria that, to a great extent ensures the patient litter, litter retention system, and patient restraint utilizes a similar dynamic performance test methodology to that which is applied to other vehicle seating and occupant restraint systems. Descriptions of the test set-up, test instrumentation, photographic/video coverage, test fixture, and performance metrics are included.
Truck Crashworthiness Committee
This SAE Recommended Practice describes the dynamic testing procedures required to evaluate the integrity of patient compartment interior Storage Compartments such as cabinets, drawers, or refillable supply pouch systems when exposed to a frontal, side or rear impact (i.e., a crash impact). Its purpose is to provide component manufacturers, ambulance builders, and end-users with testing procedures and, where appropriate, acceptance criteria that, to a great extent, ensure interior Storage Compartments or systems meet the same performance criteria across the industry. Descriptions of the test set-up, test instrumentation, photographic/video coverage, test fixture, and performance metrics are included.
Truck Crashworthiness Committee
This study investigates the characterization and dry machining performance of advanced physical vapor deposition (PVD) aluminum titanium nitride (AlTiN) and aluminum chromium titanium nitride (AlCrTiN) coatings deposited using three techniques: cathodic arc evaporation (CAE), high-power impulse magnetron sputtering (HiPIMS), and scalable pulse power plasma (S3p). The coatings were evaluated for thickness, microstructure, surface roughness, coefficient of friction (CoF), adhesion strength, and microhardness. Among the tested coatings, the S3p-deposited AlCrTiN showed the best performance, exhibiting the highest microhardness (40 GPa), the strongest adhesion (108 N), and the lowest CoF (0.25), along with a defect-free microstructure. Under the selected dry turning condition of 150 m/min cutting speed, 0.15 mm/rev feed rate, and 0.7 mm depth of cut, the S3p-deposited AlCrTiN coating achieved a maximum tool life of 10,800 mm, nearly three times higher than the CAE-deposited AlTiN coating. In contrast, CAE coatings showed comparatively lower hardness and weaker adhesion, with minimum values of 25 GPa and 68 N for C1, along with higher CoF values of 0.58–0.60. Furthermore, AlCrTiN coatings produced by HiPIMS and S3p provided 20–30% longer tool life than AlTiN coatings under identical cutting conditions, highlighting the importance of deposition technique.
Dinkar Sonawane, Gaurav
This specification covers a magnesium alloy in the form of die forgings 3 inches (76 mm) and under in nominal thickness at time of heat treatment, hand forgings 6 inches (152 mm) and under in nominal thickness, and forging stock of any size (see 8.5).
AMS D Nonferrous Alloys Committee
This specification covers a corrosion-resistant steel in the form of sheet, strip, and plate.
AMS F Corrosion and Heat Resistant Alloys Committee
G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
This SAE Standard covers unshielded cable, 22 gauge and larger, intended for use at a nominal system voltage up to 600 V or 1000 V (ACrms or DC). It is intended for use in surface vehicle electrical systems.
Cable Standards Committee
This study presents an integrated suspension system to improve the ride quality and stability of semi-trailer truck vehicles. The system consists of both an Air/MR-controlled suspension on the driver’s seat and on the truck cab, and an active air main suspension for the truck to improve vehicle stability. All components are connected to the truck and semi-trailer via a series of coupled connections. An analysis of dynamic stability reveals how the truck’s motions affect slosh forces within the semi-trailer during operation. An experimental validation of the new Air/MR suspension damper, developed using ANSYS 2023 R1 Computational Fluid Dynamics (CFD) software, yielded results consistent with prior experimental evidence. The control strategy uses a hierarchical architecture in which an inverse LSTM network controls the MR damper, accurately following the damping forces generated by a higher-level RNN controller implemented in MATLAB. The RNN system adaptively adjusts the stiffness of the cab and driver seat suspension, isolating the cab from vibrations caused by uneven roads. The truck and trailer’s main air suspension uses LQR control, using state inputs to counteract vertical motions caused by road roughness and sloshing. An integrated nonlinear co-simulation model of the truck and semi-trailer—including the truck, sloshing trailer, nonlinear air springs, and CFD-based MR damper demonstrates the control system’s effectiveness. Simulation results compared with a passive suspension system show that the proposed integrated controlled suspension system significantly reduces the truck chassis bending moment, improves ride comfort (49.98%), reduces cab body displacement (63.60%), and increases dynamic stability (57.78%). Maximizing dynamic tire load due to slosh dynamics in both half-loaded and full-loaded tanks does not affect the effective dynamic stability of tire hopping at high frequencies because the stiffness coefficient is adaptively adjusted, thereby synchronizing disturbance rejection and long-term riding comfort in frequency-based control under different road conditions.
Gad, Ahmed Shehata
This test method outlines the recommended procedure for performing radial limit load and ultimate load tests on low-speed airframe and high-speed helicopter rotor head bearings.
ACBG Plain Bearing Committee
This standard establishes definitions, guidelines, and requirements governing materials (e.g., alloy and heat-treat condition) allowed for use in chemical process test specimens when requirements call for a generic class of alloy.
AMS B Finishes Processes and Fluids Committee