Acceleration Maneuvers Research Articles

Automated Lane Changing With a Controlled Steering-Wheel Feedback Torque for Low Lateral Acceleration Purposes

To bridge the gap between autonomous and normal steering during low lateral acceleration maneuvers, a steering-wheel torque controller is developed. It consists of three controllers in series, a high-gain feedback steering-wheel torque controller, a nonlinear steering-angle controller, and a linear yaw-rate controller. A validated two degrees of freedom steering-system model, in combination with a single-track vehicle model, is used to determine the controller parameters. Driving tests with different drivers have been executed to find a comfortable steering-wheel torque/angle relation. This relation is maintained throughout the lane change by specifying the steering-wheel torque as a function of the steering-wheel angle tracking error. Experiments show promising results regarding the driver/vehicle interaction, but also show that a system to detect the lanes and the vehicle position on the road is required for further improvement.

Fuel consumption at the oversaturated signalized intersection considering queue effects: A case study in Harbin, China

Vehicles are always in an alternating state of going and stopping at oversaturated signalized intersections, which not only reduces the operational efficiency of the intersections but also greatly increases the average fuel consumption of vehicles. The purpose of this study is to propose a fuel consumption analysis method that can be adapted to the oversaturated signalized intersections. Considering queue effects, this paper proposed a way to define the judging criteria and the classification for the oversaturated state based on the intersection spacing, traffic demand, and the intersection capacity. The theoretical models were constructed for estimating vehicular fuel consumption towards two different oversaturated states and with/without automatic start and stop systems respectively, which was dependent on two main parameters of the delay and the stop that were confirmed by the definite number theory. The results show that the degree of saturation of the approach and the automatic start and stop systems have a great influence on vehicular fuel consumption at oversaturated signalized intersections, and the shorter spacing is expected for the oversaturated state II because of more deceleration and acceleration maneuvers.

A stability-guaranteed and energy-conserving torque distribution strategy for electric vehicles under extreme conditions

For electric vehicles with in-wheel motors, the torque distribution strategy is used to manipulate their dynamics to reduce energy consumption and ensure safety. Under critical conditions, it is difficult to meet the necessary requirements with a simple torque distribution due to the coupled nonlinear characteristics and corresponding safety constraints. To address these problems, a stability-guaranteed and energy-conserving torque distribution strategy is proposed for the vehicles in an innovative master-slave control framework. Considering the dynamic characteristics of tires on a low-friction-coefficient road, a nonlinear controller is designed to regulate the steering angle of the front wheel and an additional yaw moment in the active safety control layer. According to the driver’s dynamic demand and actuator constraints, a torque distribution controller based on model predictive control theory is designed in the energy-efficiency control layer. The motor efficiency map is used in the objective function to reduce energy consumption while improving and balancing motor efficiency. The proposed torque distribution strategy managed to show an increment of 4.50%, 0.80% with previous in energy saving under double lane change and straight acceleration maneuvers respectively, while the power loss does not exceed 0.08%.

Fuzzy adaptive fault tolerant IGC method for STT missiles with time-varying actuator faults and multisource uncertainties

This paper studies the integrated guidance and control (IGC) problem for a class of skid-to-turn (STT) missiles subjected to rapidly changing actuator failures and coupled multisource uncertainties. Meanwhile, during interception, the target is allowed to possess unknown and changeable maneuver accelerations. By analyzing the dominating factors in the IGC system, a nonlinear uncertain strict-feedback system suffering from matched and mismatched uncertainties is utilized to describe the IGC dynamics. Furthermore, for each subsystem, the control gain functions and their boundaries are assumed unknown, which make it difficult to design the controllers. By using a hyperbolic tangent function and estimating the bounds of the lumped disturbances, the time-varying multisource uncertainties can be handled. To compensate the unknown nonlinearities existing in the IGC system, several fuzzy logic systems are established. Furthermore, a number of reciprocal adaptive laws are developed such that unwanted effects caused by the unknown control gain functions and changing actuator gain faults can be surmounted. As a result, a novel fault tolerant IGC structure is constructed and satisfactory hit-to-kill interception performance can be obtained. Finally, the numerical simulations are provided to verify the validity and advantage of the proposed method.

Novel adaptive sliding mode guidance law against arbitrarily maneuvering target

A novel adaptive sliding mode guidance law is proposed in this article. The target is assumed to have an arbitrarily but upper bounded maneuvering acceleration which is considered as the system disturbances and uncertainties. The guidance law is consisted of three terms. The first one is a proportional navigation–type term. The second one is a term used for compensating the target maneuvering acceleration. And the last one is a term for controlling the convergence time of the line-of-sight angular rate. In this guidance law, the upper bound of the target acceleration is estimated by an adaptive estimator with a tunable updating law. Hence, the prior knowledge of the upper bound of the target acceleration is not essential for this guidance law. The novel adaptive sliding mode guidance law can guarantee the asymptotical convergence of the line-of-sight rate to zero or its neighborhood, or even the finite time convergence of the line-of-sight rate conditionally. Finally, the new theoretical findings are demonstrated by numerical simulations.

Capturability of a Sliding-Mode Guidance Law With Finite-Time Convergence

Using the Lyapunov-like approach, the capturability of a recently proposed sliding-mode guidance law, which is used for exoatmospheric interception and can guide the line-of-sight (LOS) angular rate to converge to zero or its small neighborhood in a finite time, is thoroughly analyzed. The target is assumed to have an arbitrary but upper-bounded maneuvering acceleration. A more realistic definition of capture is considered. The upper bound of the commanded acceleration is obtained and so is the capture region. The new theoretical findings are extended to the three-dimensional space with the help of the rotating LOS coordinate system.

An Unconventional Multiple Low-Cost IMU and GPS-Integrated Kinematic Positioning and Navigation Method Based on Singer Model.

To release the strong dependence of the conventional inertial navigation mechanization on the a priori low-cost inertial measurement unit (IMU) error model, this research applies an unconventional multi-sensor integration strategy to integrate multiple low-cost IMUs and a global positioning system (GPS) for mass-market automotive applications. The unconventional integration strategy utilizes a basic three-dimensional (3D) kinematic trajectory model as the system model to directly estimate navigational parameters, and it allows the measurements from all of the sensors independently participating in measurement updates. However, the less complex kinematic model cannot realize smooth transitions between different motion statuses for the road vehicle with acceleration maneuvers. In this manuscript, we establish a more practical 3D kinematic trajectory model based on a “current” statistical Singer acceleration model to realize smooth transitions for the maneuvering vehicle. In addition, taking advantage of the unconventional strategy, we individually model the systematic errors of each IMU and the measurements of all sensors, in contrast to most existing approaches that adopt the common-mode errors for different sensors of the same design. A real dataset involving a GPS and multiple IMUs is processed to validate the success of the proposed algorithm model under the unconventional integration strategy.

A Nonlinear Observer for Attitude Estimation of Vehicle-Mounted Satcom-on-the-Move

In this paper, a low-cost attitude estimation system (AES) is designed to estimate the attitude information of the vehicle utilizing MEMS inertial measurement unit (MIMU) and single baseline global positioning system (GPS). The proposed AES adopts a nonlinear attitude observer to fuse different sensors and estimate the vehicle's attitude. With the help of single baseline GPS, a maneuver accelerations compensation algorithm is used to improve the accuracy of the attitude angles and gyro biases. Modified quaternions are also used for the attitude observer to separate the yaw angle from the gravity angles easily when the single baseline GPS information is absent. The proposed AES judges the maneuver state of the vehicle depending on a switch criteria and adjusts the gain of the observer during GPS outages. The rules can efficiently detect the maneuver state of the vehicle and make full use of the inertial sensor outputs than classical rules. The experimental tests show that the proposed AES has a good attitude estimation accuracy, which meets the requirements of the Satcom-on-the-Move (SOTM) systems.

Non-collision incidents on buses due to acceleration and braking manoeuvres leading to falling events among standing passengers

BackgroundOn public transport buses, standing passengers are subject to acceleration and braking driver manoeuvres which may lead to a falling event. Purpose and proceduresThis study investigates the characteristics of such events connected to driver manoeuvres (i.e., acceleration or braking), passenger conditions (i.e., boarding, travelling, alighting), and injury severity. The data for analyses comprise three and a half years (2015–2018). All passengers were standing at the time of the fall event and were treated at hospital emergency departments (ED) after the falling event. FindingsThe results highlight aspects which may need further attention. For example, the involvement of females is not only high for the 65 ​+ ​age group, this is also the case for younger age groups which indicates that acceleration/deceleration threshold values for sustaining balance may differ by gender. Furthermore, driver manoeuvres and passenger conditions are important characteristics impacting the mechanisms of falling differently. In acceleration manoeuvres, older passengers (aged 65+) are most often involved in a fall inmediately after boarding, whereas falls during braking manoeuvres are most common while travelling, and mostly involving the 25-64 years-old age group. ConclusionsThese findings may indicate that acceleration and braking manoeuvres should be studied separately. It is worth noting that driving style might influence the risk of losing balance for standing passengers, and shortening the time to get seated can be beneficial for reducing the risk of falling, especially for the elderly users after boarding the bus.

Driving Style Clustering using Naturalistic Driving Data

Knowledge of driving styles may contribute to traffic safety, riding experience, and support the design of advanced driver-assistance systems or highly automated vehicles. This study explored the possibility of identifying driving styles directly from driving parameters using data from the Strategic Highway Research Program 2 database. Partitioning Around Medoids method was implemented to cluster driving styles based on 14 variables derived from time series records. Principal component analysis was then conducted to understand the underlying structure of the clusters and provide visualization to aid interpretation. Three clusters of driving styles were identified, for which the influential differentiating factors are speed maintained, lateral acceleration maneuver, braking, and longitudinal acceleration. Chi-square test of homogeneity was performed to compare the proportions of trips assigned to the three driving style clusters across levels of each driver attribute (age, gender, driving experience, and annual mileage). The results showed that all four attributes examined had an impact on how the trips were clustered, thus suggesting that the clusters capture individual differences in driving styles to some extent. While our results demonstrate the potential of naturalistic vehicle kinematics in capturing individuals’ driving styles, it was also possible that the identified clusters were classifying mostly drivers’ transient behaviors rather than habitual driving styles. More vehicle parameters and information about road conditions are necessary to obtain deeper insights into driving styles.

Injuries in Floorball: a Questionnaire Survey in Swiss National LeagueA Floorball Players

Rapid changes in direction, acceleration, deceleration and deception manoeuvres with rotational movements increase the risk of injuries in floorball players. Up to date, there are no data or facts available from Swiss Floorball League players demonstrating the types of injuries that occur. This study aimed to find out which injuries occur in Swiss National League A floorball players. This study was carried out in a retrospective, non- experimental design as a questionnaire survey. Five Swiss National League A floorball teams were interviewed in writing on an exposure period of 12 months. The injury rate describes the number of injuries per 1000 hours of exposure. The Wilcoxon rank sum test was used to assess the significance of the results. The significance level was set to p < 0.05 for all tests. During a calendar year, n = 71 of all players (n = 101) sustained an average of 1.14 injuries (± 1.05). The injury rate in the presented data set was 2.01. The injury rate in competition was two times higher than in training (rate ratio (RR) = 2.04). Most injuries were sprains, muscle injuries and inflammation, with muscle injuries almost exclusively affecting the thigh. Sprains usually occurred in the ankle. This study confirms the hypothesis that the susceptibility to injuries in floorball is significantly higher during competition compared with training. It can be assumed that players in whom physical activity triggers significant fatigue and emotional stress are more susceptible to injuries. Further studies should be performed to evaluate different preventative measures and to make a comparison on gender-specific vulnerability.

A Composite Guidance Law for Suppressing Measurement Noise of LOS Angular Rate

To effectively intercept a low-altitude target in clutter background, a nonsingular fast terminal sliding mode guidance law is designed. The designed guidance law can fully exploit the fast convergence characteristics of linear sliding mode control and the finite-time-convergent characteristics of terminal sliding mode control to ensure that the line-of-sight (LOS) angle converges to a desired angle in a limited time at a faster rate. Utilizing the smooth switching characteristics of the hyperbolic tangent function similar to the saturation function, a finite-time-convergent differentiator is designed. Meanwhile, a new finite-time-convergent disturbance observer designed on the tracking differentiator can effectively track the ideal LOS angular rate, suppress the measurement noise, and make a smooth estimation of the target maneuvering acceleration in clutter background. Combining the estimated value of the disturbance observer, the sign function with switch coefficient is introduced to design a composite nonsingular fast terminal sliding mode guidance law. The simulation results show that the composite guidance law can not only effectively suppress the measurement noise of the LOS angular rate and improve the accuracy of low-altitude target intercepting, but also greatly reduce the energy consumption in the interception process.

Augmented unbiased minimum-variance input and state estimation for tracking a maneuvering satellite

The technique of tracking a maneuvering satellite is significantly important for Space Situation Awareness (SSA). Traditional Kalman filters (KF) cannot robustly track unknown maneuvers. Motivated by the problem of tracking a non-cooperative maneuvering satellite, an augmented unbiased minimum-variance input and state estimation (AUMVISE) method is developed for estimating the state and the maneuver acceleration in this study. The maneuver acceleration estimate of the proposed method is proven to be more accurate than the original unbiased minimum-variance input and state estimation (UMVISE) method. Approaches based on the measurement residuals and the acceleration estimates are developed for maneuver start and end detection. The filter is switched between the AUMVISE method and the classical extended Kalman filter (EKF) to obtain an accurate tracking result during both the maneuver period and the non-maneuver period. Simulation results show that the proposed method has a suitable maneuver detection delay and outperforms the UMVISE method in estimating the state and maneuver acceleration.

Performance analysis of differential geometric guidance law against high-speed target with arbitrarily maneuvering acceleration

The interception of high-speed target with an arbitrary maneuvering acceleration causes serious troubles to the guidance and control system design of airborne missile. A novel guidance law based on the classical differential geometry curve theory was proposed not long ago. Although it is believed and numerically demonstrated that this differential geometric guidance law (DGGL) is superior to the classical pure proportional navigation (PPN) in intercepting high-speed targets, its performance has not been thoroughly analyzed. In this paper, using the Lyapunov-like approach, the performance of DGGL against the high-speed target with an arbitrary but upper-bounded maneuvering acceleration is well studied. The upper bounds of the LOS rate and commanded acceleration of DGGL are obtained, and conditions that guarantee the capture of this type of maneuvering target are also presented. The nonlinear relative dynamics between the missile and target is taken into full account. Finally, the proposed theoretical findings are demonstrated by numerical simulation examples.

Guidance law to control impact angle and time based on optimality of error dynamics

In this work, a new guidance law with a meaningful performance index is designed to satisfy terminal impact angle and impact time constraints based on optimal error dynamics, which can be used for salvo attacks or cooperative missions of multi-missile. The analytical solution of the proposed guidance law is a combination of trajectory shaping guidance law and an additional impact time error feedback term that is proportional to the difference between the desired and the true impact times. Trajectory shaping guidance law aims to achieve the desired terminal impact angle and zero miss distance, whereas the extra term aims to meet the desired impact time. The minimum and maximum feasible impact times that consider the seeker's field-of-view limit, terminal impact angle constraint, and missile's maneuvering acceleration limit are calculated to provide the feasible boundary range of the desired impact time. Numerical simulations of several engagement situations demonstrate the effectiveness of the proposed guidance law in the accuracy of terminal impact angle and impact time.

A finite-time-convergent composite guidance law with strong fault-tolerant performance

To improve the performance of tracking and intercepting the low-altitude target, a nonlinear integral sliding mode guidance law is designed firstly, which can guarantee that the line-of-sight angle converges to a desired tracking angle and the line-of-sight angular rate converges to zero in finite time. Meanwhile, to solve the chattering problem caused by the high gain coefficient of the sign function in the guidance law, a sliding mode disturbance observer is designed to estimate the maneuvering acceleration of the target. Moreover, a composite nonlinear integral sliding mode guidance law is designed by introducing the estimated value of the acceleration, which can weaken the chattering phenomenon effectively. Finally, considering the magnitude loss fault of the guidance command that may occur in the practical implementation, a composite guidance law with strong fault-tolerant performance is designed by introducing a fault compensation command, which can effectively improve the reliability of the system.

Adaptive pitch control for ships with diesel mechanical and hybrid propulsion

Shipping urgently needs to reduce its impact on the environment, both due to CO2, NOx and particulate matter (PM) emissions and due to underwater noise. On the other hand, multifunction ships such as offshore support vessels, anchor handling and towing vessels, naval vessels and wind farm construction and support vessels require fast and accurate manoeuvring and need highly reliable systems to support reduced or no crew. Diesel mechanical propulsion with controllable pitch propellers provides high efficiency and low CO2 emissions, but has traditionally been poor in manoeuvrability, can suffer from thermal overloading due to manoeuvring and requires significant measures to meet NOx and PM emission regulations. The control strategy of diesel mechanical propulsion with fixed combinator curves is one of the causes of the poor manoeuvrability, thermal overloading and cavitation noise during manoeuvring, such as slam start and intermediate acceleration manoeuvres. This paper proposes an adaptive pitch control strategy with slow integrating speed control that reduces fuel consumption, CO2, NOx and PM emissions and underwater noise, improves acceleration performance, limits engine loading and prevents engine under- and overspeed. A simulation study with a validated model of a case study Holland class Patrol Vessel demonstrates 5–15% reduction in fuel consumption and CO2 emissions, compared to the baseline transit control mode in the ship speed range from 6 to 15 kts, during constant speed sailing. Moreover, the adaptive pitch control strategy reduces acceleration time from 0 to 15 kts with the slam start procedure by 32% compared to the baseline manoeuvre control mode and by 84% for an intermediate acceleration from 10 to 15 kts, while preventing thermal overloading of the engine, during straight line manoeuvres. Combining this control strategy with hybrid propulsion, running an electric drive in parallel with the propulsion diesel engine, can potentially further reduce fuel consumption at low speeds while also improving acceleration performance even more. Therefore, hybrid propulsion plants with controllable pitch propellers and adaptive pitch control can provide a significant contribution to the urgent reduction of environmental impact of shipping and to the need for more autonomous and reliable ship systems.

Robust extended Kalman filter with input estimation for maneuver tracking

This study investigates the problem of tracking a satellite performing unknown continuous maneuvers. A new method is proposed for estimating both the state and maneuver acceleration of the satellite. The estimation of the maneuver acceleration is obtained by the combination of an unbiased minimum-variance input and state estimation method and a low-pass filter. Then a threshold-based maneuver detection approach is developed to determinate the start and end time of the unknown maneuvers. During the maneuvering period, the estimation error of the maneuver acceleration is modeled as the sum of a fluctuation error and a sudden change error. A robust extended Kalman filter is developed for dealing with the acceleration estimate error and providing state estimation. Simulation results show that, compared with the Unbiased Minimum-variance Input and State Estimation (UMISE) method, the proposed method has the same position estimation accuracy, and the velocity estimation error is reduced by about 5 times during the maneuver period. Besides, the acceleration detection and estimation accuracy of the proposed method is much higher than that of the UMISE method.

Impact Angle Control Law with Sinusoidal Evasive Maneuver for Survivability Enhancement

In this paper, a new guidance law to enhance the survivability of anti-ship missiles against anti-air threats is presented. Sinusoidal maneuver acceleration is considered as a feed-forward input to a first-order lag system dynamics on the plane. Subject to this system dynamics a planar optimal guidance law for a stationary target is then derived to achieve zero miss distance and a specified impact angle while minimizing the control effort. By independent application of this planar law for homing guidance on the vertical and the horizontal plane, three-dimensional evasive guidance is easily synthesized. The phase difference as well as the magnitude and frequency of the sinusoidal acceleration inputs for the vertical and the horizontal guidance is the design parameter to shape the three-dimensional spiral or barrel-roll evasive maneuver pattern. Enhanced survivability with the proposed law against anti-air missiles is verified via numerical simulations.

Comfort in automated driving: An analysis of preferences for different automated driving styles and their dependence on personality traits

As technical realization of highly and fully automated vehicles draws closer, attention is being shifted from sheer feasibility to the question of how an acceptable driving style and thus comfort can be implemented. It is increasingly important to determine, how highly automated vehicles should drive to ensure driving comfort for the now passive drivers. Thus far, only little research has been conducted to examine this issue. In order to lay a basis on how automated vehicles should drive to ensure passenger comfort, different variations of three central maneuvers were rated and analyzed. A simulator study (N = 72) was conducted in order to identify comfortable driving strategies. Three variations of lane changes, accelerations and decelerations were configured by manipulating acceleration and jerk, and thus the course of each maneuver. Furthermore, the influence of personality traits and self-reported driving style on preferences of differently executed automated maneuvers was analyzed. Results suggest keeping acceleration and jerk as small as possible for acceleration maneuvers. For lane changes, both small accelerations as well as an early motion feedback are advisable. Interestingly, decelerating as a manual driver would is rejected compared to two artificial alternatives. Moreover, no influence of personality traits on maneuver preference was found. Only self-reported driving style had a marginal effect on participants’ preferences. In conclusion, a recommendation for an automated driving style can be given, which was perceived as comfortable by participants regardless of their personality.