Values Of Lateral Acceleration Research Articles

Integrated control of anti-rollover for high-mobility emergency rescue vehicles

In this paper, an integrated anti-rollover control strategy is proposed to solve the rollover stability problem of emergency rescue vehicles. The integrated anti-rollover control is performed on the Active suspension system and the multi-axle steering system. Firstly, establish an eleven-degree-of-freedom coupled dynamic model for the vehicle; Secondly, the H∞/generalized H2 output feedback controller for Active suspension is designed, and the multi-axle steering LQR controller is designed; The upper level coordinated fuzzy controller is designed again, and the integrated control strategy of anti-rollover is used to integrate the Active suspension system and the multi-axle steering system. The test results show that, compared with the uncontrolled vehicle, the root mean square value of the lateral load transfer rate of the vehicle under integrated control decreased by 14.3%, 12%, and 10.9%; the root mean square values of lateral acceleration decreased by 26.8%, 22.8%, and 27.4%, respectively; the root mean square values of roll angle decreased by 27.7%, 25.2%, and 29.1%, respectively; respectively in the three-vehicle tests, and the proposed integrated control strategy for rollover prevention effectively improved the rollover prevention ability of emergency rescue vehicles.

Objective evaluation index for the comprehensive performance of intelligent vehicle lane-changing trajectory

Lane-changing behaviour is one of the most important and basic driving behaviours. Intelligent and connected vehicles must face lane-changing scenarios to achieve autonomous driving. To improve the rationality of lane-changing trajectory planning for intelligent vehicles, by analysing numerous real vehicle lane-changing trajectories in the German HighD natural driving dataset, a dimensionless lateral quantification balance index is proposed to realise a comprehensive and objective evaluation of the degree of human-likeness of lane change trajectory planning. Focused on the lateral kinematic characteristics of lane changing, a lane-changing trajectory extraction method based on the peak-to-peak value of lateral acceleration is proposed. Lateral displacement, lateral velocity, lateral acceleration and lane-changing duration are extracted from natural driving data, and the correlations between the parameters are revealed to deduce the lateral quantification balance index. With several common parametric lane-changing trajectory models of intelligent vehicles, such as sine, quintic polynomial, Gaussian and hyperbolic tangent and fifth-order Bessel models, as examples, the index values of each lane-changing trajectory model are calculated and obtained. Results show that the proposed index can balance the different requirements in lane-changing efficiency and comfort of the trajectory parameters during the lane-changing process, thus achieving a comprehensive quantitative evaluation of lateral stability, efficiency and comfort. This research establishes an intuitive and concise objective function for human-like trajectory planning and provides a basis for trajectory tracking control and real-time dynamic correction of intelligent vehicles.

Vehicles lateral acceleration and speed profiles investigation at the entry area of interchange ramps as a criterion of geometric road design

The subject of road safety is the main subject of many research programs regarding the road network infrastructure. In the present study, lateral acceleration is recorded through modern instruments, depending on passing speed for each participant driver, for four (4) interchanges and six (6) horizontal curves in total. Essentially, this study emphasizes on how the geometric roads design affects driving behavior. The main purpose is to determine the effect of on-ramp applied speed and curve geometry on lateral acceleration and to create a clear speed profile of drivers during their passage from an interchange ramp. The data collection took place in morning weekend hours, in order to avoid high traffic flows and record the vehicles motions in free flow conditions. As a result, the analysis can examine the main human factors, which affect the driving behavior, too. The selected interchange ramps are mainly trumpets, but also clover and diamond sections and the under-investigation curve radii varies between 28 and 175 meters.For each curve, the presented figures correlate the speed within the curve and the lateral acceleration, while comparisons are made between the lateral acceleration recorded in this research and the literature and guidelines limits. Additionally, V85, V50 and V15 are calculated from the total measurements, taking also into account the data from three additional horizontal curves of Schistos-Skaramagas interchange investigated one year earlier. Therefore, aggregate speed profiles are created and presented.In conclusion, the results show that an increase in the speed leads to an increase in the lateral acceleration as well. Also the limit values of lateral acceleration received by drivers into smaller-radii curves, significantly exceed the maximum driver comfort limit and the maximum driver safety limit, as well as the provided -by design guidelines- values, in contrast to larger-radii curves. Regarding the speed within the curve in respect to the horizontal radius, it was found that as the radius of the curve increases the applied speed also increases. However, this increase is more abrupt for the smaller radius curves compared to the larger ones. Moreover, de Jong's models include higher values than the measurements made in the present study and much more than those presented by Jafarov's and Zaluga's model (2020), especially in cases of large horizontal radii.

Investigation of the Performance Characteristics of the Angle-based Proportional Navigation Guidance Law

Guidance commands generated by the proportional navigation guidance (PNG) law which constitutes the most popular one among the guidance laws applied on the guidance munition fired against predetermined targets are in the form of linear acceleration or angular speed as dictated by the relevant engagement geometry. As a result of the studies in which notable linear acceleration- and angle-based guidance laws are compared, it is seen the lateral acceleration values obtained with the PNG law occur in a lower level than the results of the angle-based guidance laws. However, the angle-based guidance laws lead to lower final miss distances. In this study, the PNG law is so adapted that it yields angle-based guidance commands and then it is applied upon a short-range air-to-surface missile against a maneuvering surface target as well as the velocity pursuit guidance law that is nothing but a version of PNG law, linear homing guidance law, and body pursuit guidance law. After the computer simulations, it is observed that the angle-based PNG law produces smaller final miss distances compared to its original form. The resulting lateral accelerations are in admissible levels. Also, the engagement duration values with the target happen to be almost the same.

Analysis of the Structure of Driver Maneuvers in Different Road Conditions

The safety of road users is one of the priority issues taken into account in both the operation and design of vehicles. The presented work is part of a study that aims to develop a method for parametric assessment of driver behavior. The driving style of a driver depends on their skills and psychophysical characteristics, the type and performance of the vehicle used by the driver, and the type of road. This method involves the continuous measurement of the longitudinal and lateral acceleration values of a vehicle body. The paper analyzes how the type of road influences the structure of the maneuvers undertaken by the driver. The paper formulates criteria for distinguishing basic maneuvers (acceleration, braking, and turning). The structure of maneuvers was analyzed for two parameters: the extreme value of acceleration occurring during the execution of a given maneuver and the frequency of maneuvers during the passage of a given route. The analysis presented in this paper confirms that the type of road has a significant influence on the structure of the maneuvers undertaken by the driver.

Study on the influence of wheel polygon on the vibration characteristics of bogie system

As one of the important core components of train running parts, the wheel rail related force will directly affect the vehicle running performance and passenger comfort. Take a high-speed train as the research object, the vehicle track coupling dynamic model is established. The influence of wheel polygon on the vibration characteristics of bogie system is analyzed through simulation. The results show that when the wheel polygon wear occurs, the effective value of lateral acceleration of polygonal wheel set axle box is about 18.9 % higher than that of normal wheel set axle box; at the same speed, with the increase of the wave depth of the wheel polygon, the effective values of the transverse and vertical acceleration of the axle box gradually increase; the effective value of axle box vertical vibration acceleration caused by wheel polygon with different amplitude increases first, then decreases and then increases with the change of vehicle speed. The effective value of axle box transverse and vertical acceleration caused by wheel polygon increases with the increase of wave depth or polygon order; the analysis shows that the polygonal wear of the wheel has a great impact on the vibration characteristics of the axle box and can cause the high-frequency vibration of the axle box.

Road testing of lateral acceleration in urban bus

Lateral acceleration is one of the parameters used to assess a driver’s behaviour and the comfort of urban bus passengers. Because of its purpose, a city bus is a vehicle designed to transport large numbers of people over relatively short distances. The specific driving conditions require constant stopping and accelerating. Lateral acceleration values collected in selected road manoeuvre tests or performance tests conducted in real traffic conditions will determine the lateral vehicle movement dynamics. This paper presents the results of lateral acceleration in a urban bus, obtained during experimental studies in selected road manoeuvres on various surfaces. The surface condition and type do not substantially affect the lateral acceleration when driving on a circular track. During test drives on a circular track, the range of lateral acceleration amounts to 5.56÷7.37 m/s2. The lateral acceleration obtained during double lane change attempts amounted to 2.84÷4.42 m/s2. The maximum lateral acceleration values achieved by the urban bus on a dry and wet asphalt surface are similar.

Study of lateral acceleration of a Ford Transit car on various road surfaces

The measurement of car acceleration in time can be used to assess driving styles and safety behaviours of drivers. The values of lateral acceleration of the car can be an indication of the driver’s aggressive driving style and tendency for risky behaviour. If the lateral acceleration is too high, it may affect the car’s stability and potentially cause it to roll over. The paper outlines the results of the lateral acceleration analysis of a Ford Transit car driving in a circle and in the attempt to change two driving lanes. The tests were conducted in driving practice areas. Measurements were taken for the test vehicle driving in circles with maximum attainable velocity, and changing two driving lanes with pre-specified velocity. The tests were conducted on asphalt and concrete surfaces, in dry, wet and icy conditions. The purpose of the tests was to determine the maximum lateral acceleration of the analysed vehicle. The impact of the surface condition on the lateral acceleration of the test vehicle was also determined. The obtained results can be used as threshold values to assess driving style, and to analyse causes of accidents taking into consideration the condition of the road surface.

Tests of lateral acceleration during a controlled skid - various types of vehicles

This article presents the values of lateral acceleration during controlled slip for a passenger vehicle and a city bus. Skidding is one of the most dangerous road situations that can occur while driving a vehicle. They can happen to anyone, without exception whether someone has experience or is a young driver. The lateral accelerations during the controlled skidding presented in the article showed higher values for a passenger vehicle. The article refers to drawing attention to the lateral accelerations acting on the vehicle during the slip. It depends on the driving system of the driver whether he will be able to make the correct choice in a dangerous situation. Therefore, improving driving techniques, especially in a skidding situation, should be generally available to drivers.

Novel high-fidelity tyre model for motorcycles to be characterised by quasi-static manoeuvres – rationale and numerical validation

Although diverse tyre model formulations exist in the literature, they are suited for characterisation using a dedicated test bench, preventing parameters' estimation in driving conditions. This study defined a novel motorcycle tyre model, characterisable through driving manoeuvres using simple instrumentation consisting in an inertial measurement unit, steering position sensor and wheel speed sensors. Acquired signals were used to estimate instantaneous tyre forces, moments, slip angle and other properties, which were employed to calculate tyre model's parameters. Tyre model development and validation were performed in a simulation environment: we used a Magic Formula tyre-equipped motorcycle model to perform a set of manoeuvres, which were employed to characterise the proposed tyre model. Lastly, a set of quasi-static manoeuvres was conducted using the same motorcycle model equipped with the two tyre models, and results were compared. Comparison results showed a close reproduction of real tyre forces, moments and slips by the proposed tyre model for quasi-static manoeuvres, accurately reproducing motorcycle dynamics. Therefore, steering torque was correctly predicted for different lateral acceleration values. These results show that the proposed tyre model can be characterised, for both longitudinal and lateral dynamics, using this limited set of manoeuvres and simple instrumentation; the correctly predicted steering torque could allow the use of this tyre model for handling description.

Assessment of Active Wheelset Steering System Using Computer Simulations and Roller Rig Tests

The paper is created within a project which aims to design a system of active wheelset steering for an electric four-axle locomotive. The wheelset steering system enables reduction in forces acting in the wheel-rail contacts in a curved track and consequently a reduction in wear and maintenance costs of both vehicles and rails is achieved. The project consists of three main parts: computer simulations, scaled roller rig experiments, and field tests. The paper is focused on the fundamental aspects of the first and the second part on the project. Track curvature estimation based on the rotation of the bogies towards the car body is proposed and assessed by computer simulations across varying track radiuses, vehicle speeds, and friction conditions. The scaled roller rig has been innovated in order to simulate bogie run in a curved track with uncompensated value of lateral acceleration and instrumented with a system of measurement of lateral wheel-rail forces. The experimental bogie has been equipped with systems of active wheelset steering and measurement of axle-box forces. The experiment setup, newly developed and applied systems of forces measurement and wireless signal transmission, and results of the first experiments are described in detail. Performed computer simulations and scaled roller rig experiments show that active wheelset steering is effective and practically implementable method of reducing guiding forces acting between railway vehicle wheels and rails in a curved track.

Investigation of the Performance Characteristics of the Angle-based Proportional Navigation Guidance Law

Guidance commands generated by the proportional navigation guidance (PNG) law which constitutes the most popular one among the guidance laws applied on the guidance munition fired against predetermined targets are in the form of linear acceleration or angular speed as dictated by the relevant engagement geometry. As a result of the studies in which notable linear acceleration- and angle-based guidance laws are compared, it is seen the lateral acceleration values obtained with the PNG law occur in a lower level than the results of the angle-based guidance laws. However, the angle-based guidance laws lead to lower final miss distances. In this study, the PNG law is so adapted that it yields angle-based guidance commands and then it is applied upon a short range air-to-surface missile against a maneuvering surface target as well as the velocity pursuit guidance law that is nothing but a version of PNG law, linear homing guidance law, and body pursuit guidance law. After the computer simulations, it is observed that the angle-based PNG law produces smaller final miss distances compared to its original form. The resulting lateral accelerations are in admissible levels. Also, the engagement duration values with the target happen to be almost the same.

A Methodology for Evaluating Driving Styles in Various Road Conditions

For many institutions, it is important to evaluate a given driving technique as safe or unsafe based on measurable vehicle movement parameters. The paper constitutes a part of studies aimed at establishing a method of parameter-based evaluation of drivers in various road conditions, in other words, to create a so-called ‘driver profile’. The tests were carried out on a 650 km route, on four varying road types. Longitudinal and lateral acceleration values are used to evaluate the driving style. An analysis is presented of the impact of the type and shape of road on acceleration values. The results demonstrate that the same driver, when driving the same vehicle on an expressway, an inter-urban road or in urban traffic, will move with various acceleration values. A detailed analysis of acceleration values and distributions was conducted. Interesting conclusions were drawn after excluding the so-called ‘smooth driving’ sections, by acceleration ranges of −0.5 to 0.5 m/s2 from the analysis. This allowed for the evaluation of the structure of other longitudinal and lateral acceleration values. After this modification, the distributions showed specificity for the given road type, thereby allowing the road type used by the vehicle’s driver to be recognized based solely on the distribution.

Solutions for increasing the comfort in road vehicles based on improving the construction of the seats

To reduce the harmful vibrations to which passengers and drivers are exposed when traveling in road vehicles, various suspension systems for the vehicle, chassis or seats may be used. Most research and development is focused on reducing vertical vibrations. When the vehicle is cornering, lateral acceleration occurs, which causes discomfort to passengers. According to a number of studies, the value of lateral acceleration can be reduced if the vehicle or seats lean towards the center of the turn. This study looks at some solutions to increase comfort in road vehicles based on improving the design of the seats. New design solutions for a child tilting seat, which were developed by the authors, are presented. Road experiments have been carried out to demonstrate that the use of these seats when the vehicle is cornering can reduce the value of lateral acceleration.

Design Optimization and Application of Hybrid Bit to Reduce a Well Cost in Geothermal Field

Hybrid bit is one of the innovations developed for very hard and abrasive formations such as in geothermal field. This bit eliminates the risk of losing cones, reduces tripping time, and increaseas ROP to reduce the well cost. The stage of data processing by calculating the UCS formation using D-BOS software and design optimization based on 9-7/8" bits simulations in granodiorite formations. The 1st phase was to determine the 4 best out of 7 hybrid bit designs that were selected from the highest ROP obtained, the most stable cutter cutting force, and the lowest vibration by comparing the results of FEA modeling of 1 ft drilling simulation. The 2nd phase is to choose 1 of the best from the 4 selected by doing 50 ft of drilling dynamics simulation which is assessed by directional capability, the durability, and the lowest MSE. In this study to improve drilling optimization in geothermal field, it was found that the Z616 hybrid bit design was the most optimal one. Based on 1st phase simulation, this bit was able to produce ROP of 6.38 mph, a stable cutter cutting force, very low average lateral 2.109 g and axial vibration 0.329 g. Furthermore, for the 2nd phase simulation of 50 ft, seen from the comparison of directional capability, this bit has a 0.91 deg/100 ft DLS in rotating mode, and 6.5 deg/100ft DLS in sliding mode means quite stable when drilling in rotary mode and easy to make some angle in slide mode. By its durability, the average value of lateral acceleration is 10 g, and the lateral force is 6 klbf. By MSE side, this bit also produces the lowest average MSE value of 769 psi. From the economic view, this bit can save USD 198,625 - USD 564,712 of a well cost.

Evaluation of speed loss in bulk carriers with actual data from rough sea voyages

The evaluation of speed loss is the most important studies in the optimal ship routing. However, the mode of speed loss during rough sea voyages is complicated because of the involvement of the human factor. A speed loss analysis is conducted to improve the accuracy of evaluation of measured data extracted from actual marine conditions. First, the conventional criteria to judge the deliberate speed reduction is summarized with the conventional ship maneuvering techniques. Second, a nationwide questionnaire for marine engineers implemented for engine safety during rough sea voyages is detailed. Third, these conventional criteria are validated by analyzing the collated data on accelerations, ship motions, navigation, and engine parameters. The limiting value of vertical acceleration agrees with that obtained via practical measurements. On the contrary, the limiting values of lateral acceleration, roll motions, probabilities of deck wetness, and slamming do not agree with that obtained via measurements. The probabilities of deck wetness, slamming, and propeller racing start to increase at approximately the same instant where the deliberate speed reduction occurs. Some relations between the deck and engine parameters detailed in this paper were found to be highly correlated. Finally, the results of the analysis were used to model simpler estimations. • This study makes clear the detailed situations on the speed loss in rough sea voyages. • Related parameters are validated with the measured database for 28,000-DWT bulk carrier. • Deliberate speed reduction occurs at the starting point of deck wetness or propeller racing. • Speed loss has a boundary region at Δ V = 3–4 knots, and are correlated with pitch motion.

Transmission of lateral vibrations to children during car traveling and possibilities for their reduction

The publication addresses the need for technical solutions to reduce the transmission of lateral vibrations to passengers, especially children traveling by car in a child seat. A special design of a pendulum type tilting child seat has been proposed. Results of road trial conducted on a specific mountain road section are shown. The differences in the values of lateral accelerations acting on a child traveling in a conventional and in a tilting seat are given. The power spectral densities of lateral accelerations for both types of child seats are presented and compared. The root mean square values of lateral acceleration are given. Results for the values of the seat tilt angle are presented.

On the handling performance of a vehicle with different front-to-rear wheel torque distributions

ABSTRACTThe handling characteristic is a classical topic of vehicle dynamics. Usually, vehicle handling is studied by analyzing the understeer coefficient in quasi-steady-state maneuvers. In this paper, experimental testsare performed on an electric vehicle with four independent motors, which is able to reproduce front-wheel-drive, rear-wheel-drive and all-wheel-drive (FWD, RWD and AWD, respectively) architectures. The handling characteristics of each architecture are inferred through classical and new concepts. The study presents a procedure to compute the longitudinal and lateral tire forces, which is based on a first estimate and a subsequent correction of the tire forces that guarantee the equilibrium. A yaw moment analysis is performed to identify the contributions of the longitudinal and lateral forces. The results show a good agreement between the classical and new formulations of the understeer coefficient, and allow to infer a relationship between the understeer coefficient and the yaw moment analysis. The handling characteristics vary with speed and front-to-rear wheel torque distribution. An apparently surprising result arises at low speed: the RWD architecture is the most understeering configuration. This is discussed by analyzing the yaw moment caused by the longitudinal forces of the front tires, which is significant for high values of lateral acceleration and steering angle.

LATERAL MOVEMENT OF VEHICLES UNDER WEAK-LANE DISCIPLINE HETEROGENEOUS TRAFFIC

Safe driving can be achieved by prevention of risky situations which requires the knowledge of the vehicle dynamics and road geometry. The Indian traffic condition is heterogeneous in nature and has weak lane discipline. Hence, vehicles interactions takes place laterally also along with their longitudinal interaction. Vehicles lateral movements (interactions) are quite high due to absence of lane discipline. Therefore, the lateral acceleration of vehicles are an important variable which characterizes the corresponding vehicle dynamics. Several studies have been done by various authors on lateral acceleration in curves, however, lateral movement study of vehicles on straight road section is also important to analyze vehicles’ maneuver in such traffic (i.e. traffic stream with weak lane discipline). Therefore, the present study is about the observation of lateral movements of vehicles over different types of roads in three metropolitan cities of India (Kolkata, Mumbai and Pune) under moderate traffic conditions. Lateral acceleration variation of five different types of vehicles (SUV cars, Sedan cars, Hutch Back cars, motorized three wheeler and two wheeler) have been recorded to investigate its relationship with vehicles longitudinal characteristics (i.e. longitudinal speed) in Indian heterogeneous and weak lane disciplined traffic. Lateral acceleration values quickly rises with initial increase in speed afterward lateral acceleration values reduces with further increase in vehicles longitudinal speed. Impact of vehicle type and locations on the lateral maneuvering of vehicles have also been studied

Can accelerometry be used to distinguish between flight types in soaring birds?

Accelerometry has been used to identify behaviours through the quantification of body posture and motion for a range of species moving in different media. This technique has not been applied to flight behaviours to the same degree, having only been used to distinguish flapping from soaring flight, even though identifying the type of soaring flight could provide important insights into the factors underlying movement paths in soaring birds. This may be due to the complexities of interpreting acceleration data, as movement in the aerial environment may be influenced by phenomena such as centripetal acceleration (pulling-g). This study used high-resolution movement data on the flight of free-living Andean condors (Vultur gryphus) and a captive Eurasian griffon vulture (Gyps fulvus) to examine the influence of gravitational, dynamic and centripetal acceleration in different flight types. Flight behaviour was categorised as thermal soaring, slope soaring, gliding and flapping, using changes in altitude and heading from magnetometry data. We examined the ability of the k-nearest neighbour (KNN) algorithm to distinguish between these behaviours using acceleration data alone. Values of the vectorial static body acceleration (VeSBA) suggest that these birds experience relatively little centripetal acceleration in flight, though this varies between flight types. Centripetal acceleration appears to be of most influence during thermal soaring; consequently, it is not possible to derive bank angle from smoothed values of lateral acceleration. In contrast, the smoothed acceleration values in the dorso-ventral axis provide insight into body pitch, which varied linearly with airspeed. Classification of passive flight types via KNN was limited, with low accuracy and precision for soaring and gliding. The importance of soaring was evident in the high proportion of time each bird spent in this flight mode (52.17–84.00 %). Accelerometry alone was limited in its ability to distinguish between passive flight types, though smoothed values in the dorso-ventral axis did vary with airspeed. Other sensors, in particular the magnetometer, provided powerful methods of identifying flight behaviour and these data may be better suited for automated behavioural identification. This should provide further insight into the type and strength of updraughts available to soaring birds.