Yaw Acceleration Research Articles

Metaheuristic tuned decentralized PID controller based active suspension system for railway vehicle

AbstractA high‐speed railway system is one of the sustainable alternatives to other modes of transportation and may connect the most congested urban cities with minimum carbon emissions. However, the vibration intensity increases as the train's operating speed increases, resulting in deteriorated ride comfort and stability. Hence, this article investigates a 27‐degree‐of‐freedom (DOF) dynamic model of railway vehicles with an improved active suspension system. The decentralized control structure performs the controlling action with five optimized Proportional Integral Derivative (PID) controllers that suppress the vehicle body's vertical, lateral, pitch, roll, and yaw motions. Further, to optimize the PID parameters, three metaheuristic optimization techniques, Genetic algorithm (GA), Grey Wolf Optimization (GWO), and Flower Pollination Algorithm (FPA), are utilized, and their simulated results are compared with the passive system as well as other conventional tuning technique. Moreover, the performance of the proposed control strategy is evaluated in the frequency domain under random track irregularities, and the results are characterized in terms of power spectral densities (PSDs). The simulated results show that among the proposed metaheuristic algorithms, FPA outperforms with a significant reduction in vehicle vibration compared to other tuning methods. The percentage reduction of the vertical, lateral, pitch, rolls, and yaw accelerations is 71.4%, 35.1%, 52.8%, 48.1%, and 38.2%, respectively, ensuring enhanced vehicle ride comfort.

Vibrations control of railway vehicles using decentralized proportional integral derivative controller with flow direction optimization algorithm

The reduction of vibration-induced discomfort in vehicles is an important goal in the field of transportation engineering. Several mathematical models with various controlling techniques, from classical to modern, have been employed to achieve better ride comfort. Still, no comprehensive solution has yet been found. Therefore, this paper proposes a 17-degree-of-freedom (minimum number of coordinates) dynamic model of a full-scale railway vehicle integrated with wheel-rail contact forces and an active suspension system. Two controllers, termed system and force tracking controllers, suppress the vehicle body's vibrations. Based on a multi-loop control structure, three optimally tuned Proportional Integral Derivative controllers evaluate the desired control forces and performs the system controller’s action. While the force-tracking controller generates the command voltage to track that forces. The parameters of controllers are tuned with a novel metaheuristic optimization algorithm known as the flow direction algorithm (FDA), and the results are compared with two other optimization techniques, i.e., particle swarm optimization and ant colony optimization. The simulated results show that the ride comfort of the vehicle is improved with FDA, as the root mean square values of the lateral, roll, and yaw accelerations are reduced by 42.01%, 33.12%, and 48.24%, respectively. Moreover, the simulated results of the proposed model are validated with the experimental results of accelerations. The simulated results show that the proposed system tuned with the metaheuristic algorithm outperforms with a significant reduction in vehicle vibrations.

Design of Guidance Law for Smart Missile Based on Direct Mode Configuration with Implicit Dynamic-Inverse

The design of guidance law for smart missile based on implicit dynamic-inverse direct mode configuration is described in this paper. The dynamic-inverse theory and direct mode algorithm are applied to the design of guidance law. The pitching acceleration and yaw acceleration are designed for the pitch channel by using the augmented proportional guidance and for the yaw channel by using the dynamic-inverse theory respectively. The attacking time parameter and the attack time error equation are introduced as the constraint criteria for the design of the dynamic-inverse. According to the singular perturbation theory, the fast and slow subsystems are designed by dynamic-inverse control, and then the required control quantities are obtained by solving the relative motion equations of the missile and the target. The simulation results showed that the guidance law can fully meet the guidance trajectory performance requirements of the smart missile.

Research on Yaw Moment Control System for Race Cars Using Drive and Brake Torques

The yaw acceleration required for circuit driving is determined by the time variation of the yaw rate due to two factors: corner radius and velocity at the center of gravity. Torque vectoring systems have the advantage where the yaw moment can be changed only by the longitudinal force without changing the lateral force of the tires, which greatly affects lateral acceleration. This is expected to improve the both the spinning performance and the orbital performance, which are usually in a trade-off relationship. In this study, we proposed a yaw moment control technology that actively utilized a power unit with a brake system, which was easy to implement in a system, and compared the performance of vehicles equipped with and without the proposed system using the Milliken Research Associates moment method for quasi-steady-state analysis. The performances of lateral acceleration and yaw moment were verified using the same method, and a variable corner radius simulation for circuit driving was used to compare time and performance. The results showed the effectiveness of the proposed system.

Sensitivity-based, space rod system multi-objective design of straddle-type monorail vehicle with single-axle bogies

In order to study the influence of the space linkage system on the stability of the straddle-type monorail vehicle with single-axle bogies, the sensitivity analysis of the space linkage system is identified based on the Pearson coefficient method to determine the importance of each component of the single-axle bogies. The dynamics model of straddle-type monorail vehicle with single-axle bogies is established by the multi-rigid body dynamics. The Pearson analysis method is used to identify the key parameters of the space linkage system. Based on that, dynamic response optimization model of space bar system is developed to carry out a multi-objective suspension design optimization process. The results show that the maximum sensitivity parameter for the RMS value of yaw acceleration and pitch angle acceleration is the length of the longitudinal tow bar; there is a correlation of approximately 0.088 between the stiffness K and the damping coefficient C of the hydraulic shock absorber. After optimization the root mean square of lateral acceleration of the optimized single-axle bogie vehicle is reduced by 6.0%.

Integrated Chassis Control and Control Allocation for All Wheel Drive Electric Cars with Rear Wheel Steering

This study investigates a control strategy for torque vectoring (TV) and active rear wheel steering (RWS) using feedforward and feedback control schemes for different circumstances. A comprehensive vehicle and combined slip tire model are used to determine the secondary effect and to generate desired yaw acceleration and side slip angle rate. A model-based feedforward controller is designed to improve handling but not to track an ideal response. A feedback controller based on close loop observation is used to ensure its cornering stability. The fusion of two controllers is used to stabilize a vehicle’s lateral motion. To increase lateral performance, an optimization-based control allocation distributes the wheel torques according to the remaining tire force potential. The simulation results show that a vehicle with the proposed controller exhibits more responsive lateral dynamic behavior and greater maximum lateral acceleration. The cornering safety is also demonstrated using a standard stability test. The driving performance and stability are improved simultaneously by the proposed control strategy and the optimal control allocation scheme.

Data fusion based lane departure warning framework using fuzzy logic

Background: Lane detection is a difficult issue because of different lane circumstances. It plays an important part in advanced driver assistance systems, which give information about the centre of a host vehicle such as lane structure and lane position. Lane departure warning (LDW) is used to warn the driver about an unplanned lane exit from the original lane. The objective of this study was to develop a data-fusion LDW framework to improve the rate of detection of lane departure during daylight and at night. Methods: Vision-based LDW is a comprehensive framework based on vision-based lane detection with additional lateral offset ratio computations based on the detected X12 and X22 coordinates. The computed lateral offset ratio is used to detect lane departure based on predefined LDW identification criteria for vision-based LDW. Data fusion-based LDW was developed using a multi-input-single-output fuzzy logic controller. Data fusion involved lateral offset ratio and yaw acceleration response from the vision-based LDW and model-based vehicle dynamics frameworks. Real-life datasets were generated for simulation under the MATLAB Simulink platform. Results: Experimental results showed that fusion-based LDW achieved an average lane departure detection rate of 99.96% and 98.95% with false positive rates (FPR) of 0.04% and 1.05% using road footage clips #5–#27 in daytime and night-time, respectively. The average FPR using data fusion-based LDW reduced by 18.83% and 15.22% compared to vision-based LDW in daytime and night-time, respectively. Conclusions: The data fusion-based LDW is a novel way of reducing false lane departure detection by fusing two types of modalities to determine the correct lane departure information. The limitation is the constant warning threshold value used in the current implementation of LDW in the vision-based LDW framework. An adaptive mechanism of warning threshold taking various road structures into account could be developed to improve lane departure detection.

Study on high-speed stability of automobile based on aerodynamic lift feedback

For a long time, the impact of aerodynamic lift on the stability of high-speed vehicles has been studied only from the perspective of the aerodynamic force, and there is a lack of quantitative assessment of the vehicle body. In this paper, a model of multi-body dynamics of the vehicle was constructed by using an in-use vehicle model as the research object. Accuracy was verified using computational fluid dynamics (CFD) and compared with HD-2 (the second wind tunnel of Hunan University) wind tunnel test data. The stability of the vehicle under the condition of high-speed driving was analysed from two aspects of body acceleration and lateral displacement. The results show that the aerodynamic lift at high speed will reduce the maximum lateral acceleration and the maximum yaw acceleration of the vehicle body in the obstacle avoidance condition; and reduce the response speed of the vehicle body to driver's control. The anti-floating front bumper can effectively reduce aerodynamic lift and improve the high-speed driving stability of the vehicles.

Lane Departure Warning Estimation Using Yaw Acceleration

Abstract Lane departure collisions have contributed to the traffic accidents that cause millions of injuries and tens of thousands of casualties per year worldwide. Due to vision-based lane departure warning limitation from environmental conditions that affecting system performance, a model-based vehicle dynamics framework is proposed for estimating the lane departure event by using vehicle dynamics responses. The model-based vehicle dynamics framework mainly consists of a mathematical representation of 9-degree of freedom system, which permitted to pitch, roll, and yaw as well as to move in lateral and longitudinal directions with each tire allowed to rotate on its axle axis. The proposed model-based vehicle dynamics framework is created with a ride model, Calspan tire model, handling model, slip angle, and longitudinal slip subsystems. The vehicle speed and steering wheel angle datasets are used as the input in vehicle dynamics simulation for predicting lane departure event. Among the simulated vehicle dynamic responses, the yaw acceleration response is observed to provide earlier insight in predicting the future lane departure event compared to other vehicle dynamics responses. The proposed model-based vehicle dynamics framework had shown the effectiveness in estimating lane departure using steering wheel angle and vehicle speed inputs.

Performance study of multi-source driving yaw system for aiding yaw control of wind turbines

Multi-source driving (MSD) yaw system is widely used in large-scale wind turbines. However, due to the complex coupling effect of mechanical, electrical, and hydraulic, there is a knowledge gap on the dynamic process of the MSD yaw system. To fill this gap, a dynamic coupling model of the MSD yaw system is established. In this model, multi-way power source subsystems, transmission gearbox subsystems, and hydraulic brake subsystems are established, and the coupling of multi-way yaw subsystems are realized. Based on this model, different yaw angle control modes are studied, including comparison control and servo control. To further reflect the dynamic process in-service condition, the MSD yaw system model is integrated into a wind turbine model. An approximate solution for calculating yaw load is also presented. Through this study, the results show the established MSD yaw system model can work effectively. The difference of gear meshing gaps directly affects the distribution of yaw load. The dynamic response of the yaw system, including yaw position, yaw speed, and yaw acceleration, is affected by the changing amplitude and frequency of yaw load, but the large inertia of yaw system can restrain the fluctuation of yaw dynamic response to some extent.

Accurate Tracking of Aggressive Quadrotor Trajectories Using Incremental Nonlinear Dynamic Inversion and Differential Flatness

Autonomous unmanned aerial vehicles (UAVs) that can execute aggressive (i.e., high-speed and high-acceleration) maneuvers have attracted significant attention in the past few years. This article focuses on accurate tracking of aggressive quadcopter trajectories. We propose a novel control law for tracking of position and yaw angle and their derivatives of up to fourth order, specifically velocity, acceleration, jerk, and snap along with yaw rate and yaw acceleration. Jerk and snap are tracked using feedforward inputs for angular rate and angular acceleration based on the differential flatness of the quadcopter dynamics. Snap tracking requires direct control of body torque, which we achieve using closed-loop motor speed control based on measurements from optical encoders attached to the motors. The controller utilizes incremental nonlinear dynamic inversion (INDI) for robust tracking of linear and angular accelerations despite external disturbances, such as aerodynamic drag forces. Hence, prior modeling of aerodynamic effects is not required. We rigorously analyze the proposed control law through response analysis and demonstrate it in experiments. The controller enables a quadcopter UAV to track complex 3-D trajectories, reaching speeds up to 12.9 m/s and accelerations up to 2.1 g, while keeping the root-mean-square tracking error down to 6.6 cm, in a flight volume that is roughly 18 m ×7 m and 3-m tall. We also demonstrate the robustness of the controller by attaching a drag plate to the UAV in flight tests and by pulling on the UAV with a rope during hover.

A robust three-dimensional cooperative guidance law against maneuvering target

This paper proposes a robust three-dimensional cooperative guidance law (RTCGL) against a maneuvering target. When some missiles are intercepted during the engagement, this RTCGL integrated with a local filtering algorithm can ensure that the rest missiles hit the maneuvering target simultaneously. The pitch acceleration command is designed based on an augmented proportional navigation guidance law and can make the missile’s trajectory fall into its yaw plane. Then the three-dimensional cooperative problem is converted into a planar one. The yaw acceleration command consists of a guidance component for homing and a coordination component for simultaneous arrival. Numerical simulation results are presented to verify the effectiveness of the cooperative guidance law.

Path Following of Autonomous Underactuated Ships: A Translation–Rotation Cascade Control Approach

In this paper, a novel translation–rotation cascade control (TRCC) scheme is developed for path following of an autonomous underactuated ship suffering from unknown sideslip and complex disturbances. Salient contributions are as follows: 1) finite-time observers are devised to exactly estimate lumped unknowns including sideslip, disturbances, and virtual yaw acceleration; 2) complex unknowns are compositely compensated with finite-time convergence such that exact path following with accurate unknown rejection is achieved; 3) in lieu of detached guidance-control design in previous works, the TRCC facilitates integrated guidance-control (IGC) system in a cascade manner; 4) combining cascade analysis with Lyapunov approach, the entire IGC system is ensured to be globally uniformly asymptotically stable. Both simulation and experimental results are provided to validate the superiority of the proposed TRCC scheme.

Toward Automated Vehicle Control Beyond the Stability Limits: Drifting Along a General Path

Abstract Professional drivers in drifting competitions demonstrate accurate control over a car's position and sideslip while operating in an open-loop unstable region of state-space. Could similar approaches help autonomous cars contend with excursions past the stable handling limits, thereby improving overall safety outcomes? As a first step toward answering that question, this paper presents a novel controller framework for automated drifting along a path. The controller is derived for the general case, without reference to a nearby equilibrium point. This leads to the physically insightful result that one can use the rotation rate of the vehicle's velocity vector to track the path, while simultaneously using the yaw acceleration to stabilize sideslip. Nonlinear model inversion, in concert with low-level wheelspeed control, is then used to achieve these required state derivatives over a broad range of conditions. Experiments on MARTY, a modified 1981 DMC DeLorean, demonstrate excellent tracking of a path with varying curvature, speed, and sideslip. Comparisons to a test run without wheelspeed control highlight the importance of accounting for the rear saturated-tire wheelspeed dynamics.

Design of a central feedforward control of torque vectoring and rear-wheel steering to beneficially use tyre information

ABSTRACT This paper presents the design of a central feedforward control for the two chassis control systems rear-wheel steering (RWS) and torque vectoring (TV) which have related areas of intervention in lateral dynamics. A control strategy is presented in order to follow desired target values consisting of yaw acceleration and sideslip angle velocity. Central attention is given to the use of additional tyre information with the aim of enhancing vehicle handling and stability. With the knowledge of the mounted tyre type, an adaption law for the desired target values is derived. Although the focus is based on the usage of new tyre information, this modelling approach basically has the potential to reduce the need for coordination among the two systems RWS and TV, exploiting the synergies between both of them. Starting from an extended single-track model an exact Input–output linearisation method is used to design the feedforward control. This is followed by a proof of stability for the external and the internal dynamics of the controller. For the subsequent investigation, in a preliminary step, real-world in vehicle tests are carried out under varying tyre types with a wide spreading of characteristics. This serves as a basis to identify the most important tyre parameters for the controller and to derive the target goals. Finally, the controller is implemented in a 14-DOF non-linear entire vehicle model in Matlab/Simulink, that serves for simulations with a virtual vehicle plant. The performance of the presented feedforward control is assessed by specified objective criteria for steady-state and transient open-loop manoeuvres in lateral dynamics. These criteria are used to investigate the effectiveness of the control design with the aim to achieve the defined target motion. In addition to that, the manoeuvre results also serve to evaluate the control effort, involved in the coordinated cooperation of both systems.

Helicopter landing gear vibration analysis using Lagrange method

In this paper, landing dynamics for a helicopter fitted with an oleo pneumatic landing gear in the front and tail gears has been analysed with a seven degree of freedom mathematical model. Dynamic equations have been developed using Lagrange principle to investigate the effects of vibrations on the structure during landing phase of the helicopter. The bounce, roll, pitch, yaw acceleration response of helicopter landing obtained by numerical simulation in Matlab/Simulink. The developed model by Lagrange method will be useful to measure the vibration levels on landing and taxing of helicopter with uncertainties. This approach is also helpful to optimize the stiffness and damping properties of landing gear.

Vehicle Path Prediction Using Yaw Acceleration for Adaptive Cruise Control

In this paper, we propose a vehicle path prediction employing yaw acceleration for adaptive cruise control (ACC). First, a path prediction method employing yaw acceleration is proposed to improve the path prediction performance of ego vehicles. In the proposed method, the vehicle path is predicted by using a clothoidal cubic polynomial curve model, and for this purpose, the curvature rate, yaw rate, and longitudinal velocity are required. The curvature rate can be mathematically obtained by differentiating the yaw rate without a camera sensor. To obtain the yaw acceleration from the noisy measured yaw rate, we derive the state-space model from the steer wheel angle for the yaw rate. Then, the KF is designed by using the state-space model to estimate the yaw acceleration. Second, a multirate longitudinal control method is proposed to improve the longitudinal control performance. The multirate KF employs the constant acceleration model in order to estimate the relative distance and velocity of the target vehicle at a faster sampling rate. Then, the desired acceleration is achieved to maintain a safe headway distance or velocity by means of the longitudinal controller. Consequently, the whole ACC system operates with a faster sampling rate so that multirate control scheme reduces ripples in both the relative longitudinal distance and the desired acceleration. The performance of the proposed method was evaluated via simulations and experiments.

PID Controller of Sprayer Chassis by Sliding Mode

In order to solve the straight line drive coordinated control problem of the four-wheel independent drive sprayer chassis, the dynamic model of sprayer chassis and electromagnetic proportional valve controlled hydraulic motor model are established. The additional yaw moment is designed to rectify the deviation with sliding mode variable structure control. PID control strategy is used to calculate the control voltage adjustment of the electromagnetic proportional valve. The simulation results show that the accumulative deviation of the chassis is 0.2 m out of 100 m when the coordinated control strategy is adopted on different adhesive coefficient pavement, which is much smaller than the value without control. The test results of test prototype show that the yaw acceleration of the chassis can be as low as −0.0132 m/s2 on different adhesive coefficient pavement with coordinated control, which is smaller than the value without control, and the straight line drive requirements are met. It is feasible to combine sliding mode variable structure with PID control and use the electromagnetic proportional control technology in the straight line drive coordinated control of sprayer chassis by adding the yaw moment to rectify the deviation of chassis based on the yaw acceleration detection.

Vehicle Speed Estimation in Driving Mode for Hybrid Electric Car Using Unscented Kalman Filter

As for the four-wheel drive hybrid electric car with complex and changeable driving modes, unscented Kalman filter(UKF) is proposed for vehicle speed estimation in consideration of obtainable driving torque and electronic stability program(ESP) senor signals. Simulation platform is established according to the four-wheel drive hybrid electric car, which integrates power-train system model, nonlinear seven degree of freedom vehicle dynamics model and the dynamic union tire model. The estimation result of UKF algorithm is compared with the simulated real car's velocity. After steering wheel angle sensor, yaw angular velocity sensor and acceleration sensors are all mounted in the prototype car and the signals of two front wheel angular speed are acquired as well as the torque information of driving wheel are introduced, UKF algorithm is tested on the real vehicle road experiments, which include 8-shape route driving case on pure electric drive mode, double-lane change driving case and S-shape route driving case on four wheel hybrid drive mode. Simulation and test results show that the proposed algorithm has not only high precision, but also strong adaptability.

Research on Stability Control Based on the Wheel Speed Difference for the AT Vehicles

This paper utilizes a linear two-degree-of-freedom vehicle model to calculate the nominal value of the vehicle’s nondrive-wheel speed difference and investigates methods of estimating the yaw acceleration and sideslip angular speed. A vehicular dynamic stability control system utilizing this nondrive-wheel speed difference is then developed, which can effectively improve a vehicle’s dynamic stability at a very low cost. Vehicle cornering processes on roads of different frictions and with different vehicle speeds are explored via simulation, with speed control being applied when vehicle speed is high enough to make the vehicle unstable. Driving simulator tests of vehicle cornering capacity on roads of different friction coefficients are also conducted.