Cab Design Research Articles

An adaptive multi-objective optimization method for structure-connection-performance design of commercial vehicle cab

A variable screening-approximate model-adaptive multi-optimization algorithm integrated method is proposed to solve the high-dimensional nonlinear problems for lightweight optimization of cabs. Firstly, a full-parametric body-in-white model of the cab is established using implicit parameterization technology, and the simulation analysis of the bending and torsional stiffness, natural modal characteristics, and passive safety are established. Then, considering the structure and connection process parameters, the design variables are screened based on a gray relational analysis-TOPSIS (GRA-TOPSIS). Finally, integrated multi-objective optimization of cab structure-connection-performance is carried out by an adaptive RBF neural network optimization method, and the optimal solution is determined by the GRA-TOPSIS method. Compared with the initial model, the mass of cab is reduced by 3.28% after optimization design. It provides guidance for the lightweight design of body.

A performance-driven lightweight optimization method for material-structure coupling design of cab

A performance-driven lightweight optimization method for material-structure coupling design of cab

Design, Production and Impact Test of Multi-Axle Heavy Commercial Vehicle Cab

The main and most complex superstructure module of heavy-duty and heavy commercial vehicles is the driver-passenger cabin. While cabin design and production; It must be safe, light, rigid, ergonomic, modular, suitable for lean production, user-friendly and serviceable. But the most important of these criteria is the life safety of the crew in the cab. In this context, the cabin strength must be at a very high level. To determine the cabin strength, it is subjected to the R29 - Cabin strength test within the ECE regulations. Thanks to this test, it is possible to see the skeletal strength and behavior of the cabin in the event of an accident or collision. According to this test, the life safety of the crew inside the cabin must be prioritized, and the necessary designs and production must be carried out to ensure that the cabin suffers as little damage as possible in the event of an accident. In this way, it is aimed to maximize the security (safe area) inside the cabin by providing cabin rigidity. This scope of work; The objectives of lighter weight, shorter and easier production, assembly and disassembly, lower production costs, less labor and equipment or consumable expenses have been achieved. Additionally, in this study, the seat configuration in the cabin was increased from 1+4 to 1+5 and a crash test was performed by including another door option.

Analysis of Musculoskeletal Biomechanics of Lower Limbs of Drivers in Pedal-Operation States

In this study, to establish the biomechanical characteristics of commercial vehicle drivers’ muscles and bones while operating the three pedals, a driver pedal-operation simulator was built, and the real-life situation was reconstructed in OpenSim 3.3 software. We set up three seat heights to investigate the drivers’ lower limbs, and the research proceeded in two parts: experiment and simulation. Chinese adult males in the 95th percentile were selected as the research participants. In the experiment, Delsys wireless surface electromyography (EMG) sensors were used to collect the EMG signals of the four main muscle groups of the lower limbs when the drivers operated the three pedals. Then, we analyzed the muscle activation and the degree of muscle fatigue. The simulation was based on OpenSim software to analyze the driver’s lower limb joint angles and joint torque. The results show that the activation of the hamstrings, gastrocnemius, and rectus femoris muscles were higher in the four muscle groups. In respect of torque, in most cases, hip joint torque > knee joint torque > ankle joint torque. The knee joint angles were the largest, and the ankle joint angles changed the most. The experimental results provide a reference for improving drivers’ handling comfort in commercial vehicles and provide theoretical bases for cab design and layout optimization.

Internet of agriculture: Analyzing and predicting tractor ride comfort through supervised machine learning

The aim of this study is to improve ride comfort among tractor drivers by utilizing Internet of Things (IoT) technology and Machine Learning (ML) techniques to analyze and predict vibration exposure. The study explores the association between tractor ride characteristics, including average speed, tool depth, and pulling force, and ride comfort during actual rotary soil tillage operations. Ride comfort was evaluated by calculating the Overall Vibration Value (OVV) at three measurement locations (i.e., the floor, seat pan, and seat backrest). The study employed spectral analysis i.e., Fast Fourier Transform (FFT) and Power Spectral Density (PSD) to determine the predominant resonant frequencies. In addition, ML approaches i.e., Linear Regression (LR), Decision Tree Regressor (DTR), Support Vector Regression (SVR), Gaussian Process Regression (GPR), and Artificial Neural Network (ANN) were used to predict ride comfort response. Three hyperparameter optimization techniques, including Grid Search, Random Search, and Bayesian optimization were used. Tractor-tiller system was operated on a real agricultural field by five male tractor drivers. Vibration levels were measured along three translational axes at three measurement locations using a smart monitoring device based on the IoT concept. Average OVV magnitude was computed as 0.84 m/s2 i.e., exceeding the ISO 2631-1 (1997) threshold limits. FFT and PSD analysis revealed a variety of dominant frequencies, including resonance peaks at 2 Hz, 6–7 Hz, and 9–11 Hz. The analysis of variance (ANOVA) indicates that tractor speed and tool depth are significant variables (at the 5% level) in determining ride comfort. Regarding predictive accuracy, the ANN model exhibits the highest coefficient of determination of 0.90, followed by the SVM and GPR models with a coefficient of determination of 0.89. The DTR and LR models demonstrate slightly lower coefficient of determination values of 0.83 and 0.82, respectively. Furthermore, Bayesian optimization proved to be an effective approach in achieving more accurate predictions of tractor ride comfort. In general, the study outcomes can be utilized by tractor designers in numerous ways to optimize tractor design (such as suspension system, cab design, seat design, etc.) to improve tractor ride comfort in real field applications.

Test and evaluation of driving comfort of rice combine harvester.

During the field operation of rice combine harvester, the vibration generated by vibration component will only reduce mechanical reliability and yield, but also cause resonance in the human body, leading to a decrease in driving comfort and even damage to the driver's health. To study the impact of combine harvester vibration on driving comfort, a certain type of tracked rice combine harvester was selected as the research object, and vibration tests were carried out based on vibration source analysis in the driving cab during field harvesting operations. The study showed that under the influence of field road conditions and crop flow, the operating speed of the engine, threshing rotor, stirrer, cutting blade, threshing cylinder, vibration sieve and conveyor were fluctuating, and their rotation and reciprocating motion would produce vibration excitation in the driving cab. A spectrum analysis was conducted on the acceleration signal of the driver's cab, and it was found that vibration frequencies at three measuring points, namely the pedal, control lever, and seat, can reach up to 36.7~43.3 Hz. These frequencies can cause resonance in various parts of the driver's body, such as the head and lower limbs, leading to symptoms such as dizziness, throat discomfort, leg pain, defecation anxiety, and frequent urination, and even affect vision of the driver. At the same time, a weighted root-mean-square acceleration evaluation method was used to evaluate the driving comfort of the harvester. The evaluation method showed that the vibration at the foot pedal (Aw1 = 4.4 m/s2>2.5 m/s2) caused extreme discomfort, while the vibration at the seat (0.5 m/s2< Aw2 = 0.67 m/s2<1.0 m/s2) and the control lever (0.5 m/s2< Aw3 = 0.55 m/s2<1.0 m/s2) caused relatively less discomfort. This research can provide some reference for the optimization design of the joint harvester driver's cab.

A Novel Many-Objective Sine–Cosine Algorithm (MaOSCA) for Engineering Applications

In recent times, numerous innovative and specialized algorithms have emerged to tackle two and three multi-objective types of problems. However, their effectiveness on many-objective challenges remains uncertain. This paper introduces a new Many-objective Sine–Cosine Algorithm (MaOSCA), which employs a reference point mechanism and information feedback principle to achieve efficient, effective, productive, and robust performance. The MaOSCA algorithm’s capabilities are enhanced by incorporating multiple features that balance exploration and exploitation, direct the search towards promising areas, and prevent search stagnation. The MaOSCA’s performance is evaluated against popular algorithms such as the Non-dominated sorting genetic algorithm-III (NSGA-III), the Multi-objective Evolutionary Algorithm based on Decomposition (MOEA/D) integrated with Differential Evolution (MOEADDE), the Many-objective Particle Swarm Optimizer (MaOPSO), and the Many-objective JAYA Algorithm (MaOJAYA) across various test suites, including DTLZ1-DTLZ7 with 5, 9, and 15 objectives and car cab design, water resources management, car side impact, marine design, and 10-bar truss engineering design problems. The performance evaluation is carried out using various performance metrics. The MaOSCA demonstrates its ability to achieve well-converged and diversified solutions for most problems. The success of the MaOSCA can be attributed to the multiple features of the SCA optimizer integrated into the algorithm.

Lightweight Design of Commercial Vehicle Cab Based on Fatigue Durability

To better improve the lightweight and fatigue durability performance of the tractor cab, a multi-objective lightweight design of the cab was carried out in this study. First, the finite element model of the cab with counterweight loading was established and then confirmed by the physical testing, and use the inertial relief method to obtain stress distribution under unit load. The cab-frame rigid-flexible coupling multi-body dynamics model was built by Adams/car software. Taking the cab airbag mount displacement and acceleration signals acquired on the proving ground as the desired signals and obtaining the fatigue analysis load spectrum through Femfat-Lab virtual iteration. The fatigue simulation analysis is performed in nCode based on the Miner linear fatigue cumulative damage theory. Then, with the mass and fatigue damage values as the optimization objectives, the bending-torsional stiffness and first-order bending-torsional mode as constraints, the thickness variables are screed based on the sensitivity analysis. The experimental design was carried out using the Optimal Latin hypercube method, and the multi-objective optimal design of the cab was carried out using the Kriging approximation model fitting and particle swarm algorithm. The weight of the optimized cab is reduced by 7.8% on the basis of meeting the fatigue durability performance. Finally, a seven-axis road simulation test rig was designed to verify its fatigue durability. The results show the optimized cab can consider both lightweight and durability.

Flow and Transport Analysis and Suggested Optimal CAB Design Charts under Varying Hydraulic Conditions

Flow and Transport Analysis and Suggested Optimal CAB Design Charts under Varying Hydraulic Conditions

Validating Measurement Structure of Checklist for Evaluating Ergonomics Risks in Heavy Mobile Machinery Cabs

Heavy mobile machinery cabs and their equipment are still not well adjusted to operators, so it is not surprising that we are still witnessing huge consequences of accidents at sites where they operate. The checklist with 39 questions, based on the previous research, is formed, and its’ measurement structure has been tested on the sample of 102 transport, construction, and mining machines, including cranes, excavators, bucket wheel excavators, bulldozers, loaders, graders, backhoe loaders, trenchers, dump trucks, and scrapers by correlation analysis, Cronbach’s alpha, Spearman-Brown and Kendall’s W coefficient, exploratory factor analysis, and confirmatory factor analysis. The results validate the measurement structure of a checklist with only 17 items and five constructs. The results show that special attention should be put to the design of armrests and working conditions/exhaust gases, which are negatively correlated to cab interior space and task visibility. All other correlations between seat characteristics, the characteristics of armrests, whole-body vibration influences, reaching commands, the characteristics of cab interior space and environments, and interpersonal relationships are positive, which means that improvements to one area lead to improvements in another. Accordingly, the proposed model should be used for the fast, efficient, and cost-effective evaluation of ergonomics risks and as a guideline for further cab design improvements.

Body Models of Law Enforcement Officers for Cruiser Cab Accommodation Simulation.

This study developed multivariate law enforcement officer (LEO) body models for digital simulation of LEO accommodation in police cruiser cabs. Anthropometrically accurate digital LEO body models, representing the United States LEOs, for computerized LEO cruiser interface simulations are lacking. Twenty body dimensions (with and without gear combined) of 756 male and 218 female LEOs were collected through a stratified national survey using a data collection trailer that traveled across the US. A multivariate Principal Component Analysis (PCA) approach was used to develop digital LEO body models. Fifteen men and 15 women representing unique body size and shape composition of the LEO population were identified. A combined set of 24 male and female models (removal of 6 redundant models for which female and male models overlapped) is suggested. A set of 24 digital LEO body models in 3-dimensional form, along with their anthropometric measurements, were developed to facilitate LEO cruiser cab design. Digital modeling software developers can use the models and their anthropometric data to build digital avatars for simulated evaluation of LEO cruiser cab configuration, console communication-equipment fitting, and cruiser ingress/egress access arrangement. LEO vehicle and equipment designers also can use eight key body dimensions (i.e., stature, buttock-popliteal length, eye height sitting, knee height sitting, shoulder-grip length, popliteal height, sitting height, and body weight) of the body models to recruit 24 human subjects to physically evaluate their vehicle prototypes for improved vehicle and equipment design.

Tractor Cab Ergonomics Optimization Based on the Simplified Model of Upper Limb from the Perspective of Public Health.

The study of tractor ergonomics is both an essential part of public health and a very significant part of the scientific community's focus at the moment. It offers a foundation for the layout design of the tractor cab, making it possible to effectively avoid occupational diseases, minimize the number of safety accidents, and enhance the comfort of operation. Devices are categorized as control rod devices, knob-type devices, and steering wheels according to the various modes of operation of the tractor cab. Steering wheels are also included. The ease of handling of a number of different components was ranked according to how well they performed on the fast evaluation approach for the upper limbs. After that, in accordance with the concept that underpins this evaluation approach, the comfortable range of motion of human upper limb joints is evaluated while undergoing a variety of manipulation modalities. In conjunction with the structure of the human body and the characteristics of its movement, a streamlined point-line structure model of the human upper limb is constructed, with the H-point serving as the reference point. The problem of figuring out how to distribute the control components in the best possible way has been solved, and the optimal distribution range diagram of the steering wheel has been obtained. The ideal height for the distribution of control rod devices is around 300–400 millimeters, whereas the ideal height for the distribution of knob-type devices is approximately 200–500 millimeters. In conclusion, the cab design of the KAT2204 tractor is improved upon thanks to the analysis done in this study, which can be found above. The legitimacy of the research conclusion is confirmed by the fact that the RULA value is lower than 2, which is proved by the fact that the design findings are validated by the Creo Manikin module. The ergonomics of the tractor cab were taken into consideration when using this research approach as a reference.

Hybrid multi-objective robust design optimization of a truck cab considering fatigue life

Fatigue performance optimization without considering uncertainties of design variables can be problematic or even dangerous in real life. In this paper, a hybrid multi-objective robust design optimization methodology is proposed to make a proper tradeoff between the lightweight and fatigue durability for the design of a truck cab. However, the uncertainties, in reality, could lead to the optimized design unstable or even useless; this situation can be more serious in non-deterministic optimization. The Taguchi robust parametric design technique is adopted to refine the intervals of design variables for the subsequent optimization based on the validated simulation model against fatigue tests. Three types of dual surrogate models, namely the dual polynomial response surface, dual Kriging, and dual radial basis function methods are compared, and the dual Kriging is selected to model the mean and standard deviation of the mass and fatigue life for its high accuracy. The multi-objective particle swarm optimization algorithm is utilized to perform robust design. The Pareto fronts with different weight factors are analyzed to provide some insightful information on optimum designs. The robust optimization results demonstrate that the optimized design improves the fatigue life and reduces the mass of the truck cab significantly and becomes less sensitive to uncertainty. Different optimums can be obtained based on three different normalization techniques (Linear, vector, and LMM) and three MCDM methods (TOPSIS, WPM, and WSM) from the same Pareto front. The comparison analysis emphasizes the importance of normalization and MCDM method selection in the optimal design selection process.

Experimental modal analysis and optimal design of cab’s isolation system for a single drum vibratory roller

The purpose of this paper is to solve problems about cab’s low-frequency shaking in the direction of forward motion when vibratory roller operates. To solve this problem, a modal test for a single-drum vibratory roller is carried out by the Belgium LMS dynamic testing which is used to identify the model parameters and find out the natural frequency of the vehicle. A Finite Element Analysis (FEA) simulation is carried out to find out the reasons causing the cab’s low-frequency shaking. The model simulation results are found to be in good agreement with the experimental results. Finally, the design parameters of cab’s isolation system are optimized to reach the maximum value of the first-order natural frequency in order to avoid resonance vibration for cab at low frequency and reduce cab’s low-frequency shaking.

Study on Ergonomic Analysis of Excavator Cab

Excavators are the leading construction machinery used to mine ore and soil. It has an irreplaceable role in the completion of construction machinery tasks. Given to enable the absolute safety, it is of great necessity to analysis how to make drivers have better driving and operating experience. Therefore, this paper aims to analyze the cab of the excavator from the perspective of ergonomics. The cab design that meets the comfort requirements can be beneficial for improving the safety performance and ensuring the high efficiency of the excavator operation.

Carbon Fiber Reinforced Composite Materials for Self-supporting Subway Train Cab

In order to meet the requirement of lightweight, the design of the subway self-supporting composite subway cab is highly desired. Here we designed and developed carbon fiber reinforced composite sheets with high strength and moduli to replace the aluminum alloy used in the traditional subway cab. The tensile, compression, bending, interlaminar shear properties, and high speed impact performance of composite sheets were investigated. The results showed that the composite sheets had good mechanical properties comparable to traditional aluminum sheets, while reducing the weight of the subway cab by more than 30%. This composite is expected to be a good promising material to make the new generation of subway cab.

Research on the Aerodynamic Characteristics of Tractor-Trailers with a Parametric Cab Design

As tractor-trailer ownership has increased year-by-year, corresponding energy consumption and environmental issues have gradually become a heated issue. Approximately 45 percent of the total aerodynamic drag of tractor-trailers is attributed to the flow at the front surface of the cab, and the gap between the cab and trailer. Therefore, this study has taken a new approach to designing the shape of the cab inspired by the external forebody of the cheetah. A parametric design protruding cab was devised in this study; the length of the protruding part and the angle between this protruding part and the A pillar were two design variables. Computational fluid dynamics simulation was conducted to investigate the drag reduction effects of these new cab styling designs, and the proposed cab reduced the drag by a maximum of 8.49%. The flow characteristics around the whole body of the tractor-trailer baseline model and the parametric cab design vehicle model were analyzed using the velocity streamline graph to illuminate the change of the flow field and the drag-reduction mechanism of the proposed design. A vortex formed above the protruding part of the cab and it acted as a ‘vortex cushion’ to accelerate the speed of the air flow; accordingly, the positive and negative pressure distribution on the front surface of the cab and trailer also changed. The new parametric design has provided the possibility to adjust the forebody of the cab to an aerodynamically optimized shape, and these findings have offered useful information for the development of a new design method of the tractor-trailer to reduce aerodynamic drag and improve fuel economy.

Confirmation of the Structure of Trans‐Cyclic Azobenzene by X‐Ray Crystallography and Spectroscopic Characterization of Cyclic Azobenzene Analogs

AbstractThe photoisomerization properties of a series of cyclic azobenzene (cAb) analogs, including non‐substituted, Br‐, CN‐, carboxyl‐, and amino cAb, were compared. While the trans‐form of these analogs show different degrees of thermal stability, no spectral changes in the absorption wavelengths were observed for amino cAb upon exposure to purple light. The 15N NMR chemical shifts of cAb in both cis‐ and trans‐forms were found to show a large difference from those of aromatic azobenzene; however, the trend of difference in chemical shift is in agreement with that obtained from quantum chemical calculations. More importantly, the structure of the photoisomerization product from cis‐cAb was confirmed to be, indeed, the trans‐cAb by X‐ray diffraction experiments. The 15NMR data of the cAb isomers and confirmation of trans‐cAb through crystal structure will be of importance for future studies in the design and applications of cAb as a photoswitch.

A Set-Based Genetic Algorithm for Interval Many-Objective Optimization Problems

Interval many-objective optimization problems (IMaOPs), involving more than three objectives and at least one subjected to interval uncertainty, are ubiquitous in real-world applications. However, there have been very few effective methods for solving these problems. In this paper, we proposed a set-based genetic algorithm to effectively solve them. The original optimization problem was first transformed into a deterministic bi-objective problem, where new objectives are hyper-volume and imprecision. A set-based Pareto dominance relation was then defined to modify the fast nondominated sorting approach in NSGA-II. Additionally, set-based evolutionary schemes were suggested. Finally, our method was empirically evaluated on 39 benchmark IMaOPs as well as a car cab design problem and compared with two typical methods. The numerical results demonstrated the superiority of our method and indicated that a tradeoff approximate front between convergence and uncertainty can be produced.

On Human Factors in the Design of Locomotive Cab: An Investigation on Driver’s Cognitive and Behavioral Characteristics

In this paper an investigation on locomotive drivers’ cognitive and behavioral characteristics is conducted and advice for the redesign of locomotive cab considering human factors is proposed. The results of the investigation show that most behaviors of locomotive driving are skill- and rule-based, and previous behavior template plays an important role in locomotive driving, with an obvious process of information feed-forward. Though the operation comfort degree of all the mentioned joysticks is rated low, no significant correlation between controller’s operability and driver’s age, driving experience, handedness or educational level is found. Significant correlation and no variance are found between the speedometer and speed graphic curves on the monitor, indicating both ways for displaying running speed information should coexist to provide necessary information redundancy. According to driver’s characteristics, advice on locomotive cab redesign is proposed with focuses on ergonomic performance, consistency and readability, explicitness and simplicity, and error prevention.