Flat Road Research Articles

Analysis on the Seismic Damage Data of Flat Roads in the 2011 Off the Pacific Coast of Tohoku Earthquake

Analysis on the Seismic Damage Data of Flat Roads in the 2011 Off the Pacific Coast of Tohoku Earthquake

DESIGN AND VALIDATION OF A SURFACE PROFILING APPARATUS FOR AGRICULTURAL TERRAIN ROUGHNESS MEASUREMENTS

How to accurately and efficiently measure the profiles of the terrain on which agricultural machines operate has been an ongoing research topic. In this study, a surface profiling apparatus (profiler) was developed to measure agricultural terrain profiles along parallel tracks. The profiler is mainly composed of sensor frames, an RTK-GNSS system (Real Time Kinematics-Global Navigation Satellite Systems), laser sensors, an Inertial Measurement Unit (IMU) sensor and a data acquisition system. Along with a full description of how the terrain profiles were produced, a methodology to compensate for the tractor motion was included in the sensor data analysis. In field profiling validation, two trapezoidal bumps with known dimensions were used to assess the ability of the terrain profiler to reproduce the vertical profiles of the bumps, resulting in root mean square error (RMSE) of 3.6-4.7 mm and 4.5-5.1 mm with profiling speeds of 1.02 and 2.56 km/h, respectively. In addition, a validation test was also conducted on an asphalt road by profiling a flat road with the measuring wheels of the profiler rolling on the flat section but with the tractor wheels driving over a trapezoidal bump to excite the tractor pitch and roll motion. The measured profiles then also exhibited a flat road, which showed the ability of the profiler to remove the tractor motion from the profiling measurements.

Co-optimization of speed trajectory and power management for a fuel-cell/battery electric vehicle

With the advent of vehicle connectivity via intelligent transportation systems, the simultaneous optimization of powertrain operation and vehicle dynamics has become an important research problem to improve energy efficiency. However, this problem is still very challenging due to computational loads in terms of time and memory usage, and hence very little effort has been spent to reveal the full potential of co-optimization. Studies in the literature on eco-driving or energy-efficient operation typically preferred using a sequential optimization or eliminating some constraints for fast computation. This paper extends the authors’ previous work of determining energy-efficient speed profiles focused on vehicle dynamics by including additional state and control variables due to vehicle hybridization in application to a fuel-cell/battery electric vehicle. The results from Pontriagyn’s Minimum Principle analysis reveal that the co-optimization can be formulated with one discrete variable describing vehicle operation and another continuous variable for power distribution to reduce computation in implementing Dynamic Programming. Then, the performance of co-optimization and sequential optimization for energy-efficient driving is comprehensively analyzed and compared in terms of energy consumption by each powertrain component, operating modes, and computational cost. The total energy savings by co-optimization range from 5.3% to 24.2% for aggressive driving on a hilly terrain. Meanwhile, on a relatively flat road, the benefit of co-optimization is less significant. Nonetheless, co-optimization achieved 0.5%–5.3% reduction in total energy consumption as compared to sequential optimization.

An extended car-following model considering the low visibility in fog on a highway with slopes

To depict the effect of low-visibility foggy weather upon traffic flow on a highway with slopes, this paper proposes an extended car-following model taking into consideration the drivers’ misjudgment of the following distance and their active reduction of the velocity. By linear stability analysis, the neutral stability curves are obtained. It is shown that under all the three road conditions: uphill, flat road and downhill, drivers’ misjudgment of the following distance will change the stable regions, while having little effect on the sizes of the stable regions. Correspondingly, drivers’ active reduction of the velocity will increase the stability. The numerical simulations agree well with the analytical results. It indicates that drivers’ misjudgment contributes to a higher velocity. Meanwhile, their active reduction of the velocity helps mitigate the influences of small perturbation. Furthermore, drivers’ misjudgment of the following distance has the greatest effect on downhill and the smallest effect on uphill, so does drivers’ active reduction of the velocity.

The more (sharp) curves, the lower the risk

The risk of accident in horizontal curves is a complex function of at least the following characteristics of the curve: the radius of the curve; the length of the curve (and the resultant deflection angle); the presence of a spiral transition curve; the super-elevation of the curve; the distance to adjacent curves; and whether the curve is on a flat road, a straight gradient or a vertical curve. The interactions between these characteristics in determining accident risk in horizontal curves is only beginning to be understood. This paper summarises the results of studies that have investigated the interaction between the radius of a horizontal curve and the distance to adjacent curves. The shorter the mean distance between curves, the lower is the increase in risk for a given curve radius. The sharper neighbouring curves are, the lower is the increase in risk for a given curve radius. Thus, overall risk may not be higher on a road consisting mostly of sharp curves than on a road consisting mostly of straight sections with a few curves located far apart from each other.

Birdwatching Potential Based on Distribution of Bird Diversity in Protected Forests RPH Sumbermanjing Kulon KPH Malang

Areas with natural forest potential that are still preserved have the potential to birdwatching activities, a concept of sustainable tourism to preserve the environment and increase the participation of local communities. Protected forests in the South Malang area are natural forests which are still protected by habitat conditions for wild animals, especially for bird species. The purpose of this study was to determine the potential development of a birdwatching track based on the distribution of birds in the Protected Forest Area of Sumbermanjing Kulon KPH Malang. Make a path of observation and identify the types of birds found in protected forests. Knowing the community's response to birdwatching activities around protected forests through interviews. Data analysis was done by making a map of the distribution of maps and the potential of the observation pathway using the ArcGis 10.3 program. There are 51 species of birds with 3.4 species diversity (H ') in the high category. The potential of 22 birdwatching routes with mostly flat road conditions (59%), sloping (23%) and steep (18%). Bird species that can be found in 6 species of birds for each observation pathway. Knowledge of respondents related to the ability to recognize 3-5 species of birds 40%, recognize 70% birdwatching activities, and 83% of respondents' agree with the development of birdwatching as a tourism. Keywords: birdwatching, ecoturism, Kondang Merak, protected forest

Noise Reduction for Efficient In-Vehicle Respiration Monitoring with Accelerometers.

Toward ubiquitous vital sign monitoring, de-noising is still challenging under real driving conditions. This work intends to investigate the performance of de-noising with an additional accelerometer in different positions for respiratory rate (RR) estimation. One accelerometer was attached to the seatbelt to record the signal of respiratory movements. For noise recording, two accelerometers were attached to the car seat in two ways, i.e., (1) on the front and back side (F-B) of the seat and (2) on the left and right side (L-R). The recorded noise information was used to suppress noise in the signal and in the frequency domain. The experiment was conducted under three driving conditions, i.e., engine on, flat road and uneven road. The median of the estimated RR is for F-B 2.15 breaths per minute (bpm), and for L-R 0.93 bpm. The medians for the three driving conditions are 0.81 bpm (engine on), 0.86 bpm (flat road), and 2.53 bpm (uneven road) respectively. In conclusion, suitable positions for the noise accelerometer are on the left and right side of the seat. Further approaches are in demand to achieve a more stable estimation for the most dynamic driving conditions such as uneven roads.

The influence of the temperature of hydro-pneumatic spring into the state of tracked vehicle

Based on the multi-body dynamics model, the influence of the temperature of the hydro-pneumatic spring on the state of a lighted tracked vehicle under several driving conditions is studied. A multi-body dynamics model of chassis and body of a tracked vehicle is established, and verified with simulation and experimental results in the relevant literatures. Typical driving conditions are studied including running on a flat road with constant velocity, passing a semi-round obstacle with the radius of 200 mm, and running on a sinusoidal surface with wavelength of 2 m and amplitude of 100 mm. Some responses of the vehicle are compared and analyzed, so as to obtain the influence of the temperature of hydro-pneumatic spring. The numerical analysis results show that the temperature of hydro-pneumatic spring has a significant effect on the vehicle’s responses including height of centroid, vertical acceleration of centroid, pitch angle, track tension and gas pressure of the springs.

Selected aspects of motor vehicle dynamics on the example of a power-off straight line maneuver

In this paper the selected phenomena related to motor vehicle’s motion have been considered basing on a computer simulation. The vehicle performed a power-off straight line maneuver with different road conditions being included. All simulations have been performed in the MSC Adams/Car environment based on the available sports two-seater vehicle model, realizing the adopted maneuver at the instant speed of 100km/h. This enabled observation of the selected phenomena along the road long enough to relate them to different aspects of vehicle dynamics research. As for the randomly uneven road, almost similar and almost different profiles have been assumed for the left and right wheels of the vehicle. Additionally, two values of the coefficient determining the maximum amplitude of road irregularities have been selected: 0.3 for lower and 0.9 for higher irregularities, so the road surface conditions along with the flat road have been considered as one of the factors causing disturbances of the motor vehicle motion. Such research seems valuable from the point of view of road traffic safety and vehicle maintenance. This specific example is a presentation of the possible research on vehicle dynamics as well as a potential background for further considerations including different types of vehicles along with almost different road profiles for the left and right wheels of the given vehicle model. A power-off straight maneuver is not performed very often in normal road traffic. However, such test could be valuable when analyzing influence of the selected motor vehicle parameters, such as uneven loading, suspension characteristics, etc. on such maintenance features as stability, steerability and the influence of external disturbances acting on the moving vehicle. Further research provides different maneuvers and different simulation conditions.

ANALISIS ALTERNATIF PEMILIHAN BIAYA SIKLUS HIDUP PADA MASA PEMELIHARAAN RUAS JALAN JANTI – PRAMBANAN KM 7+759-8+750

The highway is one of the land transportation infrastructure that serves to connect one area to another for public activities such as economic s and social activities. Safe, comfortable, and efficient roads are not avoided by the availability of a flat road and no significant road damage. This research to calculate the life cycle cost analysis of the road with the calculation of pavement thickness that has been done by Ramadhani (2017). The method used in this research is by study case method, by collecting data about Janti-Prambanan Road section KM 7 + 750-8 + 750 and analyzing life cycle cost by estimating road maintenance that will be done during the life of the plan.Based on the analysis that has been done, the cost of construction or initial cost that must be issued based on the thickness of pavement set by Ramadhani (2017) with the total thickness of paved layer 50 cm is Rp. 14,089,007,000. The cost of maintenance at Alternative1 is Rp. 2.565.778.485,91 and at Alternative2 is Rp. 2,555,861,411.86. The total cost of the road life cycle in Alternative 1 is Rp. 16.654.785.485,91 while at Alternative 2 of Rp. 16,644,868,411.86. Analysis of the lifecycle cost of the two alternatives found EUAC for Alternative 1 is Rp. 65,649.89, while for Alternative 2 is Rp. 65,610.80. So that can be said by advancing the rehabilitation at least save on maintenance costs.

An investigation into the effect of road gradient and driving style on [formula omitted] emissions from a diesel vehicle driven on urban roads

This study explores the influence of different driving styles and road gradient profiles on NOX emissions in a diesel passenger vehicle on urban driving. Driving dynamics parameters were correlated with cumulative NOX emissions measured during on-road driving on urban roads. In this work, the vehicle was driven on two different urban routes, one with mostly hilly roads and the other with predominately flat roads to assess the effect of road gradient on NOX emissions. Each route was driven six times, the first drive on each route was driven very timidly, each subsequent drive systematically became more aggressive with the sixth drive being very aggressive. From the vehicle speed and road gradient data, the instantaneous vehicle energy was estimated and correlated against the instantaneous NOX emission. In order to investigate for monotonic relationships, Spearmans rank correlation coefficient was used to investigate potential correlations between NOX emissions and driving parameters. A strong positive correlation was observed between instantaneous NOX emissions and instantaneous vehicle energy irrespective of the driving behaviour. The correlation of driving dynamics parameters with NOX emissions also showed a similar trend indicating that driving aggressiveness and vehicle NOX emissions have a strong relationship. Also there is evidence that the influence of road gradient on NOX emissions decreases with an increase in driving aggressiveness.

Influencia de productos de la hidrólisis en el desempeño de un vehículo que opera con gasolina y gas natural en la altura

Introducción: En la actualidad existe un gran interés en la reducción en el uso de combustibles fósiles por la variación de los precios y los fuertes controles normativos, por lo cual se buscan métodos para disminuir el consumo de combustible en los motores de combustión interna, tales como el suministro de productos de la hidrólisis del agua en la admisión del motor.
 Objetivo: El objetivo del este trabajo es presentar los resultados de una metodología experimental aplicada para estimar el desempeño mecánico y ambiental de un vehículo alimentado con gasolina y gas natural, específicamente cuando al motor se le suministran productos resultantes de la hidrólisis del agua.
 Metodología: Para el suministro de dichos productos al vehículo se le instalo un dispositivo hidrólisis externo, y el vehículo fue instrumentado con una quinta rueda, sensores de temperatura y velocidad de revoluciones del motor, para realizar pruebas de aceleración en una carretera plana y una carretera con pendiente longitudinal. Adicionalmente, se realizaron pruebas de torque y potencia con dinamómetro de chasis y pruebas de emisiones contaminantes y de consumo de combustible. Las pruebas fueron realizadas en las afueras de la ciudad de Bogotá DC - Colombia, ubicada a 2650 m sobre el nivel del mar.
 Resultados: Los resultados muestran que los productos de la hidrólisis no mejoran el desempeño mecánico del vehículo, ya que aumentan el tiempo para llegada a las velocidades definidas en las pruebas de aceleración hasta en un 18% en el motor con gasolina y 7% en el motor con gas natural, mientras que el torque y la potencia del motor se incrementa alrededor del 1%. Por otro lado, los resultados de las pruebas de emisiones contaminantes indican que el consumo de combustible se reduce aproximadamente en un 7%.
 Conclusiones: Los resultados indican que el desempeño del vehículo no mejora, aunque el consumo de combustible disminuye, el desempeño ambiental no disminuye.

Optimization of Design Parameters for Leaf Spring by Taguchi Technique

Spring design in vehicles is one of the basic requirements in the system of suspension as by ensuring the proper design, the necessary comfort for passengers can be obtained. Thus, the car's stability on the road and in different places (the flat roads, winding roads and mountain roads) will be achieved. Given this importance, there are many factors that affect the design of springs (leaf springs). This research includes the study of three factors considered namely :( thickness, length and step) of springs. Taguchi experiment is used in determining the best among the tests performed. Then each factor was taken individually in control to get the design parameters for the leaf spring. Taguchi technique is applied in the design process of the three factors and mix levels to choose the optimal level for each factor that gives nominal of suitable displacement, stress and load. Optimal levels that have been achieved for case study of leaf spring of a total thickness of (12) mm were: Spring work in regions with high bumps. Spring work in flat areas and highways. Spring work in the middle regions (winding roads within cities). Applied cases studied were NISSAN, SCANIA and MAN automobiles to apply this rule and compare the actual design specifications of these automobiles. The output results showed a complete compatibility between these cases.

Experimental Study of Comfortableness during Hydrodynamic Torque Converter Lockup in a Construction Machinery

The comfortableness during hydrodynamic torque converter lockup in a construction machinery is investigated in this study. A motor grader is chosen as a typical construction machinery. Standard ramps are used to simulate stable working load. It is found that at conditions of flat road, the hydrodynamic torque converter locks at coupling condition, resulting in small acceleration fluctuation, little vibration dose value (VDV), and comfortable process. At ramp conditions, the hydrodynamic torque converter uses a traditional lockup strategy, which is possible to extend lockup status to higher load range. However, before the lockup process, the speed and torque differences between impeller and turbine wheels are larger. During the lockup process, the large speed difference leads to high engine inertia energy releasing rate. The large torque difference leads to high demanded engine torque change, which extends the engine adjustment ability and causes torque fluctuation. With a joint effect, three obvious acceleration fluctuations are observed, the VDVs become larger, and the lockup process becomes uncomfortable. As load increases, the comfortableness intends to get worse.

Designing, Manufacturing and Testing the Cycling Training System Featuring Magnetorheological Brake

In this study, a dual-disc magneto-rheological brake (MRB) with two coils placed on each side housing is proposed for a cycling training system. The cycling training system is integrated a positioning system to simulate the cycling process in different slope ranging from 0 to 150. By adjusting position of the bicycle, braking torque of the brake, a cyclist can experience different riding condition such as riding on flat road or steep road with the slope up to 15o.

An Assistive Device that Converses the Walking Patterns between Stairs and Flat Roads

An Assistive Device that Converses the Walking Patterns between Stairs and Flat Roads

The Effect of Using the Nitrogen in Automotive Tires on the Ride Comfort

Nitrogen as an inflation gas for passenger car and light truck tires use is widely available commercially. Consumers are confronted with a bewildering selection of offerings, and suppliers tout the purity of their nitrogen generation systems andthe effectiveness of using the gas in place of air. This paper will examine a number of issues that are key to nitrogen inflation. The first is the initial inflation of the tire with air. Since there is always some nitrogen in the tire due to the bead seating process, the inflation of a tire with nitrogen typically is done using a number of inflation and deflation cycles. The phenomenon of nitrogen uses as an alternative to air in vehicle tires without any definite information about this phenomenon. also heard that it causes many problems for tires and vehicles because they are gas and not air. Moreover, there are many problems that occur while driving with tires inflation with air. Therefore, the present research has been carried out to investigate experimentally to test the use of nitrogen in vehicle tires and their effect on ride comfort and vehicle performance. The experimental results showed that at reduced tire pressure, the air is better than Nitrogen, especially at high speeds. The nitrogen inflation reduces vehicle vibration at flat roads. Finally, it is concluded that Nitrogen is good inflating fluid for all conditions at the ideal tire pressure.

Driving Intention Identification Based on Long Short-Term Memory and A Case Study in Shifting Strategy Optimization

Identification of driving intentions has increasingly attracted wide attention since it can be a valuable reference input of vehicle intelligent control systems. In this study, the long short-term memory (LSTM) is employed to identify the longitudinal intention online with high precision. To this end, the driving intentions when the vehicle runs on a straight and flat road are divided into five categories. The vehicle driving states such as the vehicle speed and acceleration are pre-processed to label the road test data. Subsequently, a LSTM classification model is established to identify the driving intention with inputs of opening degree of the accelerator pedal, vehicle speed and brake pedal force. Identification results reveal that the highest accuracy of the proposed algorithm attains 95.36%, which is around 20% higher than that of the traditional back propagation neural network. Finally, a driving intention-perceptive gear shifting strategy is developed with the help of the built recognition algorithm, and simulation results highlight that the strategy can effectively reduce the number of shifts and achieve better fuel economy.

Vehicle Ego-Localization Based on the Fusion of Optical Flow and Feature Points Matching

To meet the requirement of vehicle real-time and precise ego-localization on the flat road of city, a vehicle ego-localization method based on the fusion of optical flow and feature points matching is proposed. A novel FAST algorithm with self-adaptive threshold is applied to detect feature points. Based on the assumption of flat plane, the improved Lucas-Kanade algorithm is carried out to track feature points, and then the custom LARSAE is used to amend vehicle offsets. Meanwhile, Hu moments are used as the feature descriptor to complete image matching, realizing vehicle motion estimation. These two methods are fused by the discrete kalman filter to update and optimize vehicle position. Experimental results show that the fusion algorithm overcomes the shortcomings of poor positioning accuracy of optical flow and the low processing speed of feature matching, and is able to provide more accurate real-time positioning output, having a certain robustness for circumstances such as illumination change and low pavement texture.

Muscle deoxygenation kinetics in cycling time trial

Background: Concentration changes of oxygenated and deoxygenated haemoglobin (O2Hb and HHb) measured by near infrared spectroscopy (NIRS) provides information about oxygen delivery and extraction at the muscular level. The kinetic response of HHb reflects the adjustment of the oxidative metabolism in skeletal muscle and could therefore be related to exercise tolerance. While most studies used laboratory cycling to investigate the kinetic responses, the effect of cycling time trials in field conditions remains to be shown. Therefore, the aim of this study was to investigate changes in HHb during maximal effort cycling time trials in field conditions. Methods: Thirteen trained cyclists and triathletes (N=13; mean ± SD: age 32 ± 7 years; body mass 74.6 ± 7.4 kg; stature 182 ± 5 cm; maximum oxygen uptake 67.9 ± 3.0 mL·min-1·kg-1; maximal power output 406 ± 39 W), completed 3 cycling time trials lasting 10, 4 and 1 min on a flat road, interspersed by a 30 min recovery period after each trial. Relative changes in HHb were recorded on the right vastus lateralis muscle with a portable continuous-wave NIRS device. Second-by-second data normalised to 100% of the response were used to resolve the amplitude, the time delay and the time constant by nonlinear regression. A repeated measure ANOVA was used to compare the parameter estimates across the time trial durations. Results: The mean power output during the 10-, 4- and 1- minute cycling time trials was 352 ± 45, 385 ± 49 and 525 ± 73 W, respectively (p=0.001). No significant differences were observed for cadence during the 10- vs. 1-minute cycling time trials (p=0.264), however significant differences were observed between 4- vs. 1-minute (p=0.05) The parameter estimates of the kinetic response were significantly affected by time trial duration. The amplitude for 10- vs. 1- minute (78.20 ± 8.42 vs. 89.16 ± 6.82; p = 0.022) as well as for 4- vs. 1-minute (74.99 ± 6.12 vs. 89.16 ± 6.82; p = 0.006) cycling time trial duration showed significant differences. Moreover, significant effects can be reported for the 10- vs. 1-minute time delay parameter (9.54 ± 2.07 s vs. 3.65 ± 1.71s; p = 0.001). Mean response time also demonstrated significant differences for 10- vs. 1-minute cycling time trials (13.45 ± 2.39 s vs. 6.85 ± 1.90 s; p = 0.001). No significant differences were reported for the time constant among the different cycling time trial durations (p>0.05). Discussion: These findings support that the physiological response to high intensity exercise during multiple cycling time trial durations could be monitored by alterations in muscle deoxygenation kinetic parameters. Furthermore, these results imply that changes at the microvascular level are time dependent when exposed to maximal exhaustion. However further research is recommended to support these findings of muscle deoxygenation kinetics during cycling time trial in field conditions.