Fabrication and Characterization of Steel-Base Metal Matrix Composites Reinforced by Yttria Nanoparticles through Friction Stir Processing

Friction Stir Processing (FSP) was used to fabricate metal matrix composite, based on steel and reinforced with nano-sized yttrium oxide powder. The powder was packed in a narrow longitudinal groove of 2 mm depth and 1 mm width cut in the steel plate’s rear surface. Different rotation speeds of 500–1500 rpm were used, at a fixed traveling speed of 50 mm.min−1. Single-pass and two passes, with the same conditions, were applied. The direction of the second pass was opposite to that of the first pass. After the first pass, complete nugget zones were obtained when the rotation speeds were more than 700 rpm with some particles agglomeration. The added particles showed as narrow elliptical bands, with a band pitch equal to the rotation speed over traveling speed. Performing the second FSP pass in the opposite direction resulted in better particles distributions. Almost defect-free composite materials, with homogenously distributed yttria nano-sized particles, were obtained after two passes when rotation speeds more than 700 rpm were used. The resulting steel matrix grains were refined from ~60 μm of the base metal to less than 3 μm of the processed nugget zone matrix. The hardness and the tensile strength of the fabricated materials improved almost two-fold over the base metal. Uniform microhardness values within the nugget areas were observed at higher rotational speeds. The ductility and toughness of the fabricated composites were reduced compared to the base metal.

Investigating the impact of Innovative Treatments on Driving Behavior at School Bus Stops: A Driving Simulator Study

The illegal overtaking/crossing of stopped school buses has been identified as one of the leading causes of students’ injuries and fatalities. The likelihood of students in getting involved in a school bus-related crash increases during loading/unloading. The main objective of this driving simulator study was to study the effectiveness of different treatments in improving students’ safety by reducing the illegal overtaking/crossing of stopped school buses. Treatments used in this research are LED, Road Narrowing and Red Pavement. All proposed treatments were compared with the control condition (i.e., typical condition in the State of Qatar). Seventy-two subjects with valid Qatari driving license were invited to participate in this study. Each subject was exposed to three situations (i.e., Situation 1: the school bus is stopped in the same traveling direction, Situation 2: the school bus is stopped in the opposite traveling direction, Situation 3: the school bus is not present at the bus stop). Results showed that LED and Road Narrowing treatments were effective in reducing the illegal overtaking/crossing of stopped school buses. Moreover, the stopping behavior for drivers in LED and Road Narrowing was more consistent compared to the Red Pavement and control conditions. Finally, LED and Road Narrowing treatments motivated drivers to reduce their traveling speed by 5.16 km/h and 5.11 km/h, respectively, even with the absence of the school bus. Taking into account the results from this study, we recommend the proposed LED and Road Narrowing as potentially effective treatments to improve students’ safety at school bus stop locations.

Road traffic noise mapping based on aerial photographs - sound power level determination of road vehicles

As the first step to obtain a city urban area noise map of road traffic noise, sound power levels of vehicles on the roads should be accurately estimated over a wide area. In Japan, ASJ RTN-Model 2018 was proposed as the representative road traffic noise prediction model, and by using the model sound power level of a vehicle can be determined if the vehicle type, traveling speed, and driving mode are known. As such data on urban road network, the Ministry of Land, Infrastructure and Transport of Japan publishes the road traffic census including road traffic volume and travel speed of major roads in Japan. The data, however, is limited to major roads and there is no data on minor roads. In this study, to estimate noise condition and situation on arbitrary road, a method for estimating the traveling speed and the traffic volume of vehicles on the road from aerial photographs was examined. Road traffic noise levels along several roads in Tokyo were analyzed by the proposed method and the validity of the calculation results were verified by comparing with short-time measurement results obtained along the target roads.

Research on the water and land motion performance of an amphibious vehicle

The key motions of land and water are analyzed for a designed amphibious carrier robot. On land, based on the characteristics of the multi-joint crawler, the robot has planned two gaits for climbing steps on land. The kinematic models of climbing steps and climbing steps are established for the two planned gaits, and the maximum height that the robot can climb steps is obtained based, Based on the laws of dynamics, the stability equation of the robot under strong transient impact is established to obtain the conditions for the robot to maintain its own stability when the robot is under strong transient impact during traveling, which provides a theoretical basis for the attitude control of the robot arm. In the water, the fluid numerical method is used to simulate the underwater motion of the robot's swing arm in the extended and retracted state, obtain the traveling resistance and surface pressure of the robot's swing arm crawler in the two states, analyze the relationship between the robot's traveling resistance and speed, obtain the relationship expression between the robot's traveling resistance and the traveling speed, and provide data support of the state selection and speed setting of the robot's underwater crawler.

A novel system for measuring vehicle speed via analog signals of pyroelectric infrared sensors

This paper presents a method of measuring transportation vehicle’s speed via analog signals of a couple of pyroelectric infrared sensors. The measuring system is located along the roadside with the assumption that optical axes of the sensors are parallel to each other and perpendicular to the moving direction of vehicles. A cross-correlation method combined with interpolation has been used in order to determine the time delay between two output signals, thus defining the traveling speed of the target. The experiment results show that the proposed method has an error of less than 5 km/h over the speed range of 20–90 km/h.

Florida Department of Transportation’s Enhanced Hydroplaning Prediction Tool

Florida Department of Transportation (FDOT) recently developed and implemented a new hydroplaning prediction (HP) program for predicting the traveling speed at which a vehicle would start hydroplaning. The tool was developed as part of the effort to reduce hydroplaning accidents and is being used during the roadway design phase to evaluate the hydroplaning potential of Florida’s roadways. This paper presents an overview of FDOT’s HP program and demonstrates how it may be used. The tool incorporates a total of four water film thickness models and three hydroplaning speed models developed in the past, allowing for a total of 12 model combinations for the hydroplaning analysis. The tool also offers different analysis options that may be used to meet a variety of FDOT’s needs. As demonstrated in this paper, the primary use of the new HP tool is for checking the final geometric roadway design parameters for hydroplaning potential. In addition, the HP program can also be used as a forensic investigation tool for identifying specific locations that exhibit higher potential for hydroplaning.

Tracking Control of an Autonomous Head Feeding Combine

This study aims to develop an autonomous combine harvester. A manual steering combine harvester was modified autonomously using navigation systems of an RTK-DGPS, a gyroscope, and crawler speed sensors. These sensors could determine the combine position and heading required to guide the path. The control system is processed for these navigation sensors' data to make the decision of combine movement. Moreover, it commands the actuator to move the steering lever mechanism. The steering control's desired heading angle was determined from lateral error, heading error, and the traveling speed. In this study, the combined harvester's average forward traveling speed was set at 0.17 m/s, adjusted to a navigation sensor's sampling rate of 5 Hz and the steering mechanism delay. The preliminary test showed the combine could turn by pivoting one of its tracks which turned the radius was into 0.4 m. Furthermore, a guidance control system of the combine harvester was developed based on this test result. The developed guidance control system was successfully guiding the combine to follow the harvesting path. The test results showed that the root mean square of the lateral error was less than 0.1 m.

Reduction of Pesticide Use in Fresh-Cut Salad Production through Artificial Intelligence

Incorrect pesticide use in plant protection often involve a risk to the health of operators and consumers and can have negative impacts on the environment and the crops. The application of artificial intelligence techniques can help the reduction of the volume sprayed, decreasing these impacts. In Italy, the production of ready-to-eat salad in greenhouses requires usually from 8 to 12 treatments per year. Moreover, inappropriate sprayers are frequently used, being originally designed for open-field operations. To solve this problem, a small vehicle suitable for moving over rough ground (named “rover”), was designed, able to carry out treatments based on a single row pass in the greenhouse, devoted to reduce significantly the sprayed product amount. To ascertain its potential, the prototype has been tested at two growth stages of some salad cultivars, adopting different nozzles and boom settings. Parameters such as boom height, nozzle spacing and inclination, pump pressure and rover traveling speed were studied. To assess the effectiveness of the spraying coverage, for each run several water-sensitive papers were placed throughout the vegetation. Compared to the commonly distributed mixture volume (1000 L/ha), the prototype is able to reduce up to 55% of product sprayed, but still assure an excellent crop coverage.

Application of Lateral Overturning and Backward Rollover Analysis in a Multi-Purpose Agricultural Machine Developed in South Korea

This study analyzed the lateral overturning and backward rollover characteristics of a multi-purpose agricultural machine recently developed in South Korea. Free body diagrams for theoretical analysis and a three-dimensional model for dynamic simulation were created by reflecting the actual dimensions and material properties of the multi-purpose agricultural machine. The simulation model was verified using the minimum turning radius and angle of static falling down sidelong derived through the certified performance test. The lateral overturning and backward rollover characteristics of the multi-purpose agricultural machine were analyzed using a verified simulation model and theoretical equations derived through literature review. In the lateral overturning analysis, the critical traveling speed at which lateral overturning occurs was derived according to the inner steering angle of the front wheels under steady-state turning conditions. In the backward rollover analysis, the critical angular velocity and theoretical traveling speed of the main body at which backward rollover occurs were derived according to lifting angle of the front wheels. There was no significant difference between the theoretical analysis and simulation results at 5% significance level, and we derived the appropriate traveling speed conditions of the multi-purpose agricultural machine that do not cause lateral overturning and backward rollover.

Measuring and Comparing Forces Acting on Moldboard Plow and Para-Plow with Wing to Replace Moldboard Plow with Para-Plow for Tillage and Modeling It Using Adaptive Neuro-Fuzzy Interface System (ANFIS)

The objective of this study was to measure the draft, vertical, and lateral forces acting on the moldboard plow, para-plow without a wing, para-plow with forward-bent wing, and para-plow with a backward-bent wing at three working depths and three forward speeds in clay loam soil to investigate the use of a suitable para-plow instead of the moldboard plow. Also, modeling the draft, vertical, and lateral forces acting on the implements using Adaptive Neuro-Fuzzy Interface System (ANFIS) was another objective of this research. To measure the draft, vertical, and lateral forces, a three-point hitch dynamometer was used. The results showed that, with the increment of the forward speed and working depth, the draft force required by the used implements increased. This increase was also true for vertical and lateral forces acting on the implements. Modeling of the draft, vertical, and lateral forces acting on the implements was performed using the effective parameters of the implements, working depth, and forward traveling speed using the (ANFIS) fuzzy neural system model. The root mean square error (RMSE) for the draft, vertical, and lateral forces for the above models were obtained equal to 0.121, 0.014, and 0.016, respectively.