Light Cargo Research Articles

Hybrid Zwitterionic Hydrogels with Encoded Differential Swelling and Programmed Deformation for Small-Scale Robotics.

Stimuli-responsive shape-morphing hydrogels with self-healing and tunable physiochemical properties are excellent candidates for functional building blocks of untethered small-scale soft robots. With mechanical properties similar to soft organs and tissues, such robots enable minimally invasive medical procedures, such as cargo/cell transportation. In this work, responsive hydrogels based on zwitterionic/acrylate chemistry with self-healing and stimuli-responsiveness are synthesized. Such hydrogels are then judiciously cut and pasted to form hybrid constructs with predetermined swelling and elastic anisotropy. This method is used to program hydrogel constructs with predetermined 2D-to-3D deformation upon exposure to different environmental ionic strengths. Untethered soft robotic functionalities are demonstrated, such as actuation, magnetic locomotion, and targeted transport of soft and light cargo in flooded media. The proposed hydrogel expands the repertoire of functional materials for fabricating small-scale soft robots.

Investigating the Effects of Cargo Weight and its Distribution on the Dynamic Performance of a High-Speed Planing Hull

The aim of this article is to evaluate the effects of cargo relative weight and its distribution along the boat’s length in addition to the relative water wavelength on the dynamic performance of a high-speed planing hull. Here, the dynamic performance is measured by the intensity of the boat’s heave and pitch motions. The Zarnick’s strip theory, which divides the vessel’s hull into equal lateral sections, is used to study the applied forces on the vessel, and a MATLAB code is provided based on it. It is demonstrated that increasing the cargo weight and its distribution result in more heave and pitch, and the maximum amount of them are observed in the wave with a length of about 5 times the length of the boat. In addition, the interactive effects of cargo weight and its distribution on the heave and pitch motions are affected by the relative wavelength. Therefore, the more centralized cargo distribution is preferred to increase the dynamic performance of a heavy planing boat with cargo weights more than 50% of the boat’s weight, while moving in short waves (λ⁄L<4); and for light cargo weight, less than 50% of the boat’s weight, the favorite cargo distribution is broad. When the boat sails in long waves, the desired distribution is reversed.

Cascade PID Control for Altitude and Angular Position Stabilization of 6-DOF UAV Quadcopter

UAVs are commonly used in transportation, especially in the express delivery of light cargo parcels. However, controlling UAVs is difficult because of their complex structure and wide range of operations in space. The research contribution is proposed a cascade control structure using six PID controllers for the 6-DOF UAV quadcopter, that ensures the altitude angulars positions control at the desired values and maintains flight balance stability for the 6-DOF UAV quadcopter. First, the mathematical dynamic models for the 6-DOF UAV quadcopter have been researched and developed, including the translational dynamic mathematical model and the rotational dynamic mathematical model of the 6-DOF UAV quadcopter. This is a complex object with strong nonlinearity and difficult control. And then, the article introduces the method of designing six PID controllers for 6-DOF UAV quadcopter to meet the requirements, based on applying the Ziegler-Nichols experimental method. Applying the Ziegler-Nichols experimental method makes the process of designing a UAV quadcopter control system simple, straightforward and heuristics with fast controller parameters tuning. Next, the article presents the results of modeling and simulation of the 6-DOF UAV quadcopter control system on Matlab/Simulink. The simulation results show that the six proposed PID controllers have ensured the flight balance stability at the desired altitude and angular positions with overshoot less than 20%, steady-state error less than 1%. This shows the prospect of applying the proposed PID control method to physical UAVs, easily adjusting PID parameters to suit the flight environment.

Programmable nanocomposites of cellulose nanocrystals and zwitterionic hydrogels for soft robotics

Stimuli-responsive hydrogels have garnered significant attention as a versatile class of soft actuators. Introducing anisotropic properties, and shape-change programmability to responsive hydrogels promises a host of opportunities in the development of soft robots. Herein we report the synthesis of pH-responsive hydrogel nanocomposites with predetermined microstructural anisotropy, shape-transformation, and self-healing. Our hydrogel nanocomposites are largely composed of zwitterionic monomers and asymmetric cellulose nanocrystals. While the zwitterionic nature of the network imparts both self-healing and cytocompatibility to our hydrogel nanocomposites, the shear-induced alignment of cellulose nanocrystals renders their anisotropic swelling and mechanical properties. Thanks to the self-healing properties, we utilized a cut-and-paste approach to program reversible, and complex deformation into our hydrogels. As a proof-of-concept, we demonstrated the transport of light cargo using tethered and untethered soft robots made from our hydrogels. We believe the proposed material system introduce a powerful toolbox for the development of future generations of biomedical soft robots.

Development of a single subfloor plate for a light cargo vehicle in sandwich construction

AbstractThe Institute for Vehicle Concepts of the German Aerospace Center is developing new concepts for very light vehicles. One of these concepts is a light freight vehicle for urban logistics. The complete chassis is designed as a sandwich structure. Challenges in using these sandwich structures are the introduction of loads and joining technology. Additionally, the structure should be easy and efficient to produce. This leads to the question, if it is possible to use a single sandwich subfloor plate as the load‐bearing structure of this vehicle. As a solution, the implementation of through‐the‐thickness inserts, which are mounted in the production process of the sandwich structure are proposed. Validation with simulations will be presented and the production process of such structures will be illustrated.

ANALYSIS OF BRAKE SYSTEMS IN MOTOR VEHICLES USING PRACTICAL EXAMPLES FROM THE ASPECT OF THEIR DIAGNOSTICS

The part of the braking system that has the task of transmitting the command activated by the driver to thebrakes is called the transmission mechanism. The transmission mechanism itself can be different depending on howit is constructed and conceptually executed. As for the conceptual solution, the question arises as to whether thetransmission method itself must be such that the driver's command is only transmitted to the brakes or the driver'scommand itself is handed over to a separate energy system. The energy system itself can be such that it additionallyhelps the activation of the brakes (servo brake force boosters) or completely takes over the activation of the brakes,with the creation of a certain braking force on the wheels, and these are the so-called mechanisms with full servoaction. Today we have the following transmission mechanisms in use: Mechanical transmission, hydraulic with orwithout servo amplification, hydraulic with full servo action, pneumatic with full servo action, hydro-pneumaticwith servo amplification or with full servo action. The very choice of these systems depends on a large number offactors, but the main one is - how much energy must be delivered to the brakes. Each of these systems is explainedseparately in the paper. A mechanical transmission mechanism is a system that does not have any additional servoamplification, but the command of the driver or the person operating the machine is directly transmitted to thebrakes. Based on this, we can conclude that the application of this transmission mechanism in brake systems is quitelimited. Today, this transmission mechanism is only used as a service brake on some slower trucks and tractors. Thehydraulic transmission mechanism is the system that is most common in brake systems of passenger, light cargo anddelivery vehicles. In the case of vehicles weighing up to 1000 kg, the driver alone is sufficient to develop thenecessary energy for braking, so it is not necessary to additionally support the braking force with servo boosters. Butthat's why smaller trucks and delivery vehicles need additional help from a servo booster to activate the brakingforce. Servo amplifiers have become an integral part of the equipment in passenger vehicles primarily due to thesafety, security and comfort of passengers. In contrast to the mechanical transmission, this system is morecomplicated in terms of performance and its operation is based on the transmission of pressure through the brakefluid from the main brake cylinder to the brake cylinder in the brakes. The pressure created by the brake fluid actson the pistons in the cylinder itself and in this way force is created and the brakes are activated. The main advantageof this system is the very safety and safer braking, because with the hydraulic system it is possible to make adistribution in several independent branches to the cylinders on the brakes, and this is one of the basic satisfactoryrequirements in the ECE regulation that the brakes must also have an auxiliary braking system in case dismissal ofthe principal. The system itself consists of: the pedal, which is activated by pressing the foot on the pedal itself, themain brake cylinder, the distribution system, the working brake cylinders in the brakes and the brake itself.

Comparative investigation on ultimate strength of hull girder with laser-welded web-core sandwich deck

This paper numerically studies the ultimate strength characteristics of the hull girder with the upper deck made of the laser-welded web-core sandwich plates subjected to the vertical bending, the horizontal bending, the torsion and the combined loads among them. The hull girder with the upper sandwich deck is designed from the typical midship section of a light cargo ship as the prototype on the basis of equal cross-sectional area. Compared with the prototype hull girder, the advantages of the hull girder with the upper sandwich deck in the ultimate strength are fully demonstrated in this paper. The results show that by using the laser-welded web-core sandwich deck, the stiffness of the hull girder under sagging has been improved. The sagging ultimate strength of the hull girder can be increased by 15%, and the horizontal bending ultimate strength can be increased by 6.2%. The finite laser weld rotation stiffness has no significant effect on the ultimate strength of the hull girder with the upper sandwich deck. Based on the numerical results, the ultimate strength interaction relationships for the hull girders under the combined two or three moments are established with high accuracy.

Вплив конструктивних і експлуатаційних факторів на стійкість руху автопоїзда з причепом категорії О1

The issues of stability and controllability of cars and road trains (ATZ) in connection with their practical importance have been studied by many researchers. If the issues of transportation of bulky goods are studied well enough, then for the transportation of light cargo, which uses low-capacity road trains with simple single- or two-axle trailers, the issues of stability are not fully studied. Recommendations for changing the design parameters to improve a particular type of stability are different and sometimes contradict the requirements for other performance of the car, in particular, its smoothness and passability. Qualitative assessment of stability is performed on the basis of the general theory of stability of motion AM Lyapunov. Steady motion according to Lyapunov is realized in a previously unknown region of initial perturbations, which are called the region of attraction of undisturbed motion. There is a problem of defining the boundaries of this area. To solve it, the system of equations of plane-parallel motion of a road train with a trailer of category O1 was improved, from which the critical speed of rectilinear motion and the rate of oscillation instability were determined, and the factors influencing its numerical value were analyzed. The analysis of calculations showed that in the event of perturbation at speeds up to 31 m / s (30.8 m / s) the nature of changes in the lateral and angular velocities of the traction vehicle during the transient process is extinguished. Under the same conditions, when the velocity increases above 31 m / s (31.5 m / s), the nature of the change in lateral and angular velocities also fades, but there are fluctuations. At increase in speed to 32 m / s fluctuations of parameters of movement will be divergent that will lead to loss of stability and impossibility of the further movement. This movement should be considered unstable, which should be avoided. The stability of motion can be judged to a greater extent by the magnitude of the lateral accelerations acting in the center of mass of the individual links. The stability of the road train under consideration at nominal parameters of loading, air pressure in tires of all wheels, symmetrical loading of the trailer, loading on the traction coupling device within 500 N is provided, in particular critical speed of rectilinear movement made 33,97 m / s. oscillating instability 31.5 m / s), which is much higher than the normalized value of the maximum speed for road trains with trailers of category O1 (25 m / s), the maximum lateral acceleration when performing maneuvers such as circular motion, steering wheel jerk and "shift" is not exceeded the maximum allowable 0.45g.

Urban Freight Last Mile Logistics—Challenges and Opportunities to Improve Sustainability: A Literature Review

Last mile logistics (LML) is the least efficient and complex part of supply chain. The main objective of this study was to identify major challenges of urban freight LML and opportunities for intervention. For this, 42 peer-reviewed full papers published after 2010 and three additional references were used. The findings indicated that urban freight flow has a trend of steady growth. The main driving forces behind this steady growth are population growth, urbanization, densification, globalization, online and omni-channel (OC) retailing, and urban economic development. Using typology analysis, three main potential freight LML configurations were mapped and discussed. Freight LML configurations that involve light cargo vehicles and cargo bike-based delivery schemes could be more attractive freight LML models if the delivery failure is minimized. The LML challenges were categorized as technological, infrastructural, LML system and management, and logistic cost related challenges, and discussed broadly. Similarly, the potential opportunities were discussed from environmental, economic, and social sustainability aspects. Finally, this report has pinpointed future potential research agendas related to LML. The study could be a knowledge base useful for academicians and practitioners, logistics and technical service providers, policy makers, and customers.

Situational characteristics of fatal pedestrian accidents involving vehicles traveling at low speeds in Japan

Objective: This study aimed to investigate the situational characteristics of fatal pedestrian accidents involving vehicles traveling at low speeds in Japan. We focused on vehicles with 4 or more wheels. Such characteristics included daytime or nighttime conditions, road type, vehicle behaviors preceding the accident, and vehicle impact locations.Methods: Pedestrian fatality data on vehicle–pedestrian accidents were obtained from the Institute for Traffic Accident Research and Data Analysis of Japan (ITARDA) from 2005 to 2014. Nine vehicle classifications were considered: Trucks with gross vehicle weight (GVW) ≥7.5 tons and <7.5 tons, buses, box vans, minivans, sport utility vehicles (SUVs), sedans, light passenger cars (LPCs), and light cargo vans (LCVs). We compared the situational daytime or nighttime conditions, road type, vehicle behaviors preceding the accident, and vehicle impact locations for accident-involved vehicles traveling at low and higher speeds across all vehicle types.Results: The results indicate that pedestrian fatalities involving vehicles traveling at low speeds occurred more often under daytime conditions across all vehicle types. At signalized intersections, the relative proportions of pedestrian fatalities were significantly higher when vehicles were traveling at low speed, except when the accidents involved box vans or SUVs. Similarly, when vehicles turned right, the relative proportions of pedestrian fatalities were significantly higher when vehicles traveling at low speed were involved across all vehicle types. In terms of the frontal right vehicle impact location, the relative proportions of pedestrian fatalities were significantly higher when trucks with GVW ≥7.5 tons or <7.5 tons, sedans, or LCVs traveling at low speed were involved.Conclusions: The situational characteristics of fatal pedestrian accidents involving vehicles traveling at low speeds identified in this study can guide targeted development of new traffic safety regulations or technologies specific to vehicle–pedestrian interactions at low vehicle travel speeds (i.e., driver alert devices or automated emergency braking systems). Ultimately, these developments can improve pedestrian safety by reducing the frequency or severity of vehicle–pedestrian accidents for vehicles turning right at intersections and/or reducing the number of resultant pedestrian fatalities.

Reflecting upon the humanitarian use of unmanned aerial vehicles (drones).

Nine years after the earthquake in Haiti and the appearance of the concept of &ldquo;humanitarian drones&rdquo;, it remains a poorly discussed yet highly controversial issue. Emergency mapping and light cargo deliveries to inaccessible areas are only some of the most popular ways in which drones are currently used for post-disaster relief and health crisis management by first responders around the world. On the other hand, every single successful use for drones is always followed by controversy about the problems caused by that very same, initially successful, use. However, examples of good practices will contribute to the investigation, study and analysis of the ways in which new, cutting-edge technologies such as drones can be implemented and adapted to meet the needs and requirements of humanitarian organisations and local communities affected by disasters. The issue is how and under what circumstances drone use can potentially fulfil humanitarian functions, particularly in the aftermath of a disaster, and how this type of technology could be deployed in non-violent, ethically desirable ways as part of the humanitarian response. In conclusion, it is questionable whether the benefits of using drones outnumber the moral obstacles they raise, and whether they will eventually be considered an inseparable part of humanitarian aid as well as a cutting-edge technological toy.

Factors in Fatal Injuries to Cyclists Impacted by Five Types of Vehicles

The factors in fatal injuries to cyclists in collisions with five different types of vehicles were examined using data from the Institute for Traffic Accident Research and Data Analysis in Japan for the period 2004 ~ 2013. The vehicle types were sedans, minivans, box vans, light passenger cars (LPCs), and light cargo vans (LCVs). The analyses focused on cyclist age, gender, main body regions that suffered fatal injuries, and vehicle travel speeds. Cyclists aged 75+ years made up the largest group of fatalities in collisions with sedans, box vans, LPCs, and LCVs, whereas those aged 13 ~ 64 years made up the largest group of fatalities in collisions with minivans. Head injuries were the most frequent injuries in cyclist fatalities. The percentage of head injuries in fatalities of cyclists aged 75+ years was significantly higher than that for cyclists aged 13 ~ 64 years for box vans, but significantly lower for sedans, LPCs, and LCVs. For sedans, the percentage of hip injuries in fatalities of cyclists aged 75+ years was significantly higher than that of cyclists aged 13 ~ 64 years. Cyclist fatalities due to hip injuries were significantly more common for females than for males in collisions with sedans, LPCs, and LCVs.

Static and Dynamic Analysis for a Swept Back Dihedral Wing and its Optimization

For a stable flight, it is required adequate stability of the aircraft to have good conditions of navigability. The wing dihedral angle, the format, the position and the amount of wings are factors affecting the lateral stability of any aircraft (small or large). The purpose of this paper is study the applicability of dihedral wings in aircrafts, simulating the applications in a small aircraft. Thus, through theoretical final analysis, we can observe the use of dihedral angle implies some viability and it is going to bring significant improvement in performance and stability of the aircraft during the flight. The parameters used in this study were based on the project of a cargo radio controlled aircraft designed by Urutau Aero design, Research and Competition team, to the SAE Brazil Aero design Competition in which engineering students must design a robust and light cargo radio controlled aircraft.

Planning transport functions following a major Wellington, New Zealand, earthquake

Wellington’s (New Zealand) current road network has some clear vulnerabilities in the event of a major earthquake. Following such an event, the metropolitan area would be cut off by way of existing land routes for around 4 months (until the completion of construction of a key road into the region). Planning has been led by the Ministry of Civil Defence and Emergency Management (MCDEM) and the Wellington Region Emergency Management Office (WREMO) on initiatives to recover transport functions and avoid a potential humanitarian crisis. This has required close engagement with various utility providers, including road network providers and port and airport authorities, along with ferry operators and logistics organisations. While the recovery of the airport will provide quick access for passengers and light cargo, the recovery of the roll-on–roll-off (Roro) ferries, with their innate flexibility of use, will enable larger-scale freight to be brought into the region. The uncertainties around the availability of resilient infrastructure for the Roros to moor up to has led to assessments of the potential use of barges and pontoons which would allow unloading of the Roros. This paper describes the process by which MCDEM and WREMO have worked with the respective stakeholders to develop emergency plans.

DEVELOPMENT OF PUSHBROOM AIRBORNE CAMERA SYSTEM USING MULTISPECTRUM LINE SCAN INDUSTRIAL CAMERA

One of the steps on mastery the remote sensing technology (inderaja) for satellite was the development of aerial camera prototype that could be an alternative for LAPAN light cargo aircraft mission (LAPAN Surveillance Aircraft, LSA-01). This system was expected could be operated to fulfill the emptiness or change the remote sensing data of optical satellite as the observer of vegetation covered by cloud. On this research, it was developed a prototype of pushbroom airborne camera 4-channels spectrum with very high resolution that worked on wavelength range seem near infra-red/ NIR used simple components that were available in the commercial market (commercial off-the-shelf/ COTS components). This research also developed georeference imagery software module used method of direct georeference rigorous model that had been applied on SPOT satellite. For this one, it was installed supported sensory for GPS and IMU as the writer of location coordinate and camera behavior while doing the imagery exposure or acquisition. The testing result gave confirmation that COTS components, such as industry camera LQ-200CL, and lower class GPS and IMU could be integrated became a cheaper remote sensing system, which its imagery product could be corrected systematically. The corrected data product showed images with GSD 0.4m still had positioning mistakes on average 157m (400 pixel) from the original position on GoogleEarth. On spectro-radiomatic aspect, the used camera had much higher sensitivity of NIR channel than the looked-channel so it caused bored faster. On the future, this system needed to be fixed by increasing the rate of GPS/ IMU data updates, and increased enough time resolution system so that the synchronization process and the availability supported data for completing more accurate georeference process. Besides, the sensitivity of NIR channel needed to be lower down to make it balance to the looked-channel.

Features of serious pedestrian injuries in vehicle-to-pedestrian accidents in Japan

ABSTRACTThis study clarifies vehicle accident scenarios in which pedestrians suffer serious injuries. We investigated the characteristics of serious pedestrian injuries in accidents, using vehicle-to-pedestrian accident data for 1999 and 2009 in Japan. We focused on the main body region of seriously injured pedestrians considering different factors including the accident year, vehicle type, travel speed, and pedestrian gender and age. The results indicate that sedans, mini vans and light passenger cars tended to injure pedestrians’ legs more frequently, while box vans and light cargo vans tended to injure the head more frequently. The results also show that female pedestrians suffered hip injuries more often than male pedestrians in accidents involving sedans, mini vans, light passenger cars and light cargo vans. In accidents involving sedans, it was revealed that the head and hip were injured statistically more frequently at high vehicle travel speed than at low vehicle travel speed in all age groups.

Effects of cargo types and load efficiency on airline cargo revenues

Numerous factors affect air cargo revenue management. Air cargo companies base their cargo charges on whichever is the greater of gross weight or volumetric weight. We developed a cargo consolidation model based on air cargo characteristics, and investigated the effect of cargo density, the Density Ratio of Heavy cargo to Light cargo (DRHL), and the percentage of small cargo on the chargeable weights and revenues of airlines. The empirical results show that a higher DRHL indicates greater chargeable weight, and that as the DRHL climbs to a certain level, the extent of chargeable cargo weights tends to stabilize gradually. The closer the cargo density approaches the most suitable loading density for a flight, the greater the chargeable weight is. A higher proportion of small cargo loaded on an aircraft means higher airline revenue. Our results can effectively combine types of air cargo to increase loading rates and revenues for airlines.

Risks of Serious Injuries and Fatalities of Cyclists Associated with Impact Velocities of Cars in Car-Cyclist Accidents in Japan.

The main purpose of this study is to define the relationship between the car impact velocity and serious injury risk or fatality risk of cyclists. The authors investigated the risks of serious injuries and fatalities of cyclists using vehicle-cyclist accident data from the database of the Institute for Traffic Accident Research and Data Analysis (ITARDA) in Japan. The vehicle types considered are sedans, mini vans, box vans, light passenger cars and light cargo vans. The results revealed that a 10-km/h decrease in the impact velocity could reduce the severe injury risk and fatality risk for impact velocities of 40 km/h or higher. Specifically, when the impact velocity was less than or equal to 30 km/h, the serious injury risks were less than 21% and the fatality risks were less than or equal to 1% for the above listed vehicle types. Therefore, if the Collision Damage Mitigation Braking System (CDMBS) equipped vehicles can perform its functions effectively so as to reduce the impact velocities, then cyclist injuries will likely be significantly reduced. Another purpose of this study is to assess the effect of wearing a helmet for protection of the cyclist's head. Impact experiment results showed that the measured head injury criterion (HIC) with helmets are lower than that of head-form impactor without a helmet, reducing the HIC by 57%.

The Snaking Stability of Passenger Cars with Light Cargo Trailers

This paper presents research conducted to determine whether the detailed MBS model presented in the paper is applicable to modelling the snaking phenomenon and to validate the model, including the parameter values, so that it can be used in further research. Experiments and simulations both show – and with good agreement – that the system of a passenger car and a cargo trailer can become unstable at motorway velocities if the trailer is loaded inappropriately. Based on an analysis of the measured data, the impact-damping phenomenon and its influence on snaking damping have been identified. An MBS analysis of the computational-fluid-dynamics-determined aerodynamic influences on the system’s response to an impulse disturbance has shown these influences to be negligible. We have devised the principles and apparatus for measuring the steering-wheel angle, the articulation angle and the lateral force of the trailer’s tow bar. Measuring the last of these makes possible an on-the-fly determination of the trailer’s yaw inertia, one of the most influential parameters with respect to the snaking phenomenon.

Safety assessment characteristics of pedestrian legform impactors in vehicle-front impact tests

This study investigated the characteristics of safety assessment results of front-area vehicle impact tests carried out using the Transport Research Laboratory (TRL) legform impactor and a flexible legform impactor (FLEX legform impactor). Different types of vehicles (sedan, sport utility vehicle, high-roof K-car, and light cargo van) were examined. The impact locations in the study were the center of the bumper and an extremely stiff structure of the bumper (i.e., in front of the side member) of each tested vehicle. The measured injury criteria were normalized by injury assessment reference values of each legform impactor. The test results for center and side-member impacts indicated that there were no significant differences in ligament injury assessments derived from the normalized knee ligament injury measures between the TRL legform impactor and the FLEX legform impactor. Evaluations made using the TRL legform impactor and the FLEX legform impactor are thus similar in the vehicle safety investigation for knee ligament injury. Vehicle-center impact test results revealed that the tibia fracture assessments derived from the normalized tibia fracture measures did not significantly differ between the TRL legform impactor and the FLEX legform impactor. However, for an impact against an extremely stiff structure, there was a difference in the tibia fracture assessment between the FLEX legform impactor and the TRL legform impactor owing to their different sensor types.