Roll Dynamics Model Research Articles

An adaptive model predictive control for coupled yaw and rollover stability of vehicle during corner maneuvers

This paper presents a control strategy to achieve yaw and roll stability by taking into account the physical interaction between the yaw and roll dynamics to prevent vehicle collisions in hilly or curved terrain. The mathematical model is formulated utilizing a roll dynamic model with a small tyre slip angle and a bicycle model with two degrees of freedom considering coupling of yaw and roll dynamics. An adaptive model predictive controller and a PID controller are included in the proposed control methodology so that a real-time scenario of variation in the longitudinal velocity and friction coefficient is considered. Stability limits are established based on the yaw rate, sideslip, and roll motions of the vehicle, taking into account the effects of the road angle. The friction coefficients of 0.4 and 0.8 are chosen for wet and dry road surfaces to show manoeuvrability and force the vehicle to avoid rollover condition. Using numerical simulations in Matlab R2022a, the effectiveness of the designed controller is assessed. A root mean square error (RMSE) is calculated for the proposed methodology for the evaluation of the performance and the values are obtained as 3.032 and 3.912 for friction coefficient of 0.8 for yaw rate and roll angle respectively. On comparing with the other methodology, it is found that the performance of the proposed method is better based on RMSE. Also, the fluctuations at the corners are removed and the variables are bound inside the stability limit, thus avoiding the vehicle from accidents in hilly areas. The robustness of the controller towards increasing the mass of the vehicle by 5% and 10% is found to be good.

Roll dynamic model and steering stability analysis of the counterbalance forklift truck with considering hierarchical rollover

The dynamic model of a counterbalance forklift truck is established, and the validations under various operational conditions are studied. The roll motion of the counterbalance forklift is expressed by four degrees of freedom with consideration given to the independent roll motion between the body and chassis, the variation of the roll axis, and the contact between the body limit block and rear axle. Furthermore, testing under turning on firm ground and driving over obstacle conditions are conducted for verifying the dynamic response characteristic of the established model. In addition, numerical simulations are performed to investigate the effect of forklift structural parameters and road roughness excitation on the roll dynamics of forklifts. Finally, the rationality of evaluating the forklift roll state by load transfer ratio (LTR) is discussed. Simulation results are well in harmony with experiment results, suggesting that the proposed dynamic model can be an effective tool for stability analysis of counterbalance forklift trucks. This work provides theoretical foundations for the development of improved anti-rollover control, ultimately leading to enhanced stability and safety of forklifts.

Research on anti-rollover warning control of heavy dump truck lifting based on sliding mode-robust control

In order to improve the rollover stability of heavy dump trucks during lifting and unloading under special circumstances and prevent heavy dump trucks from overturning, a sliding mode-robust control based on anti-rollover early warning control method for heavy dump trucks lifting and unloading was proposed. A four-degree-freedom heavy dump truck lifting and unloading roll dynamic model was established, and the accuracy of the model was verified in the MATLAB/Simulink simulation environment. The controller was designed by combining sliding mode robust control based on HJI theory and active suspension control. The ratio of the gravity carried by the wheel with the lighter bearing capacity to the total gravity of the heavy dump truck was used as the evaluation index for rollover warning. Under two different simulation conditions, compared with conventional sliding mode control and no control, the rollover evaluation index and roll angles were analyzed under three control methods. The results showed that the anti-rollover early warning control method for lifting and unloading of heavy dump trucks proposed in this paper had better anti-rollover capability and better stability.

Integrated Control for Path Tracking and Stability Based on the Model Predictive Control for Four-Wheel Independently Driven Electric Vehicles

Four-wheel independently driven electric vehicles are prone to rollover when driving at high speeds on high-adhesion roads and to sideslip on low-adhesion roads, increasing the risks associated with such vehicles. To solve this problem, this study proposes a path tracking and stability-integrated controller based on a model predictive control algorithm. First, a vehicle planar dynamics model and a roll dynamics model are established, and the lateral velocity, yaw rate, roll angle, and roll angle velocity of the vehicle are estimated based on an unscented Kalman filter. The lateral stiffness of the tires is estimated online according to the real-time feedback state of the vehicle. Then, the path tracking controller, roll stability controller, and lateral stability controller are designed. An integrated control strategy is designed for the path tracking and stability, and the conditions and coordination strategies for the vehicle roll and lateral stability state in the path tracking are studied. The simulation results show that the proposed algorithm can effectively limit the lateral load transfer rate on high-adhesion roads and the sideslip angle on low-adhesion roads at high speeds. Hence, the driving stability of the vehicle under different road adhesion coefficients can be ensured and the path tracking performance can be improved.

Research on roll stability of articulated engineering vehicles based on dynamic lateral transfer load

A 16-degree-of-freedom non-linear roll dynamic model is developed for an articulated engineering vehicle considering non-linear road excitations and non-linear characteristics of vehicle structures. In addition, a variable step-size numerical method is proposed to solve the non-linear dynamic model. The proposed numerical method can improve the calculation accuracy and the computational stability. Through the proposed dynamic model, an equation is derived considering time-varying tire load characteristics to reflect the roll stability of an articulated engineering vehicle. Using the proposed roll stability equation, the driving stability can be effectively evaluated for an articulated engineering vehicle with different system parameters. The analysis results show that the roll stability decreases significantly with the increase in vehicle speed, centroid height of engineering vehicle, or lateral slope angle. The influence of vehicle speed and lateral slope angle on roll stability is greater than that of the centroid height of engineering vehicle. When steering on the road with a lateral slope angle, the roll angle and the lateral load transfer ratio curves fluctuate with time. As the lateral slope angle increases, the fluctuation is stronger. Overall, the proposed model can accurately evaluate the roll stability of a driving articulated engineering vehicle and accurately determine the unstable tilting of an articulated engineering vehicle.

A Novel Roll and Pitch Estimation Approach for a Ground Vehicle Stability Improvement Using a Low Cost IMU.

Onboard attitude estimation for a ground vehicle is persuaded by its application in active anti-roll bar design. Conventionally, the attitude estimation problem for a ground vehicle is a complex one, and computationally, its solution is very intensive. Lateral load transfer is an important parameter which should be taken in account for all roll stability control systems. This parameter is directly related to vehicle roll angle, which can be measured using devices such as dual antenna global positioning system (GPS) which is a costly technique, and this led to the current work in which we developed a simple and robust attitude estimation technique that is tested on a ground vehicle for roll mitigation. In the first phase Luenberger and Sliding mode observer is implemented using simplest roll dynamics model to measure the roll angle of a vehicle and the validation of results is carried using commercial software, CarSim® (CarSim, Ann Arbor, MI, USA). In the second phase of research, complementary and Kalman filters have been designed for attitude estimation. In the third phase, a low-cost inertial measurement unit (IMU) is mounted on a vehicle, and both the complementary filter (CF) and Kalman filter (KF) are applied independently to measure the data for both smooth and uneven terrains at four different frequencies. We compared the simulated and real-time results of roll and pitch angles obtained using the complementary and Kalman filters. Using the proposed method, the achieved root mean square error (RMSE) is less than 0.73 degree for pitch and 0.68 degree for roll, with a sample time of 2 ms. Thus, a warning signal can be generated to mitigate roll over. Hence, we claim that our proposed method can provide a low-cost solution to the roll-over problem for a road vehicle.

Robust static output feedback H∞-controller design for three degree of freedom integrated bus lateral, yaw, roll dynamics model

In this paper, a three-degree-of freedom (3 DOF) integrated vehicle lateral, yaw, roll dynamics model with optimal control design have been proposed to improve the bus lateral stability and handling performance. First, a 3 DOF vehicle model for a passenger bus is introduced. The 3 DOF model dynamics include the vehicle steering wheel angle, forward speed, yaw motion, sideslip angle, lateral acceleration and the rolling motion. Then, the presented 3 DOF model is used to design the robust static output feedback [Formula: see text] controller for both nominal system and uncertain system. The proposed controller is designed to improve the bus lateral stability and handling performance by controlling the yaw rate during normal driving and maneuvers. For the robust static output feedback [Formula: see text] controller, the norm bounded uncertainty is considered to simulate the variation of vehicle forward velocity uncertainty. The robust controller is designed to check the lateral stability of the bus at different forward velocity and at different velocity uncertainty. The controllers are synthesized within the [Formula: see text] control approach and the controllers’ design conditions are given within the Linear Matrix Inequalities (LMIs) framework. Numerical simulations have been carried out to demonstrate the effectiveness of the proposed controllers. The obtained simulation results show that the designed nominal and robust controllers enhance the lateral stability of the bus by reducing the amplitude of the yaw rate, lateral acceleration and rolling motion. Hence, the improvements in bus lateral stability and handling performance are achieved.

CИНТЕЗ РОБАСТНОГО ПІД-РЕГУЛЯТОРА ДЛЯ НЕВИЗНАЧЕНОЇ НЕЛІНІЙНОЇ МОДЕЛІ БПЛА З ВИКОРИСТАННЯМ ШТУЧНОЇ МОДЕЛІ ПОСИЛЕННЯ І ТИМЧАСОВОЇ ЗАТРИМКИ

Estimations of the flight vehicles aerodynamic coefficients through the theoretical, numerical, wind tunnel and flight-test methods have always errors and uncertainties. Nonlinear dynamics of the unmanned aerial vehicle due to speed variations, as well as variability and uncertainty of the aerodynamic coefficients can be considered as an uncertain model. A robust proportional-integral-derivative controller is designed based on the nonlinear optimization in the time domain for the uncertain nonlinear dynamical model of the unmanned aerial vehicle. Artificial gain and time-delay models are added to achieve required stability margins as system robustness during the robust proportional-integral-derivative control design. The aerodynamic coefficients are divided into two groups on the basis of the output vector's sensitivity to the aerodynamic coefficients. Nonlinear optimization of the criterion is performed in two steps for the robust proportional-integral-derivative controller design. In the first step of the design, nominal values are used for coefficients with low-sensitivity, and upper and lower limits are used only for high sensitive aerodynamic coefficients. In the second step, the upper and lower limits are applied all of the aerodynamic coefficients to evaluate and re-adjust the robust proportional-integral-derivative controller parameters. The robust controller is designed for the uncertain nonlinear roll and lateral dynamic model of the Skywalker X8 flying wing to show the effectiveness of the proposed method to guarantee the stability margins. In the given example during the design of the robust controller, with adding of the artificial gain and time-delay model in the control loop the controller parameters are changed. This regulator increases the phase stability margin by about 10 degrees and the gain stability margin by about two for the family of the equivalent uncertain linear models.

Model predictive control of vehicle roll-over with experimental verification

This paper presents a model predictive approach to directly control untripped vehicle roll-over. First, a novel real-time estimation scheme is designed to provide the vehicle roll angle using an observer on a combined model of vehicle kinematics and roll dynamics. This angle is used in an integrated directional and roll dynamics model for the prediction of vehicle states and roll-over index. The roll-over prevention objective is specified as a soft constraint to ensure persistent feasibility. If the controller foresees impending vehicle roll-over, it intervenes and reduces the roll-over index by torque vectoring. Software simulations are used to assess the effectiveness of the proposed roll-over control method in the industry standard fishhook maneuvers. In addition, the accuracy and performance of the suggested estimation and control algorithms are verified in double-lane change and flick maneuvers on dry asphalt with an instrumented test vehicle. The results show accurate estimation of the vehicle roll angle and excellent control on roll-over index with the proposed predictive roll-over controller.

A novel tripped rollover prevention system for commercial trucks with air suspensions at low speeds

This paper presents a novel system to avoid tripped rollovers at low-speed operations for commercial vehicles with air suspension systems. This is of particular significance since truck rollovers have become a serious road safety problem, which usually lead to severe injuries and fatalities. Several active anti-rollover systems have been proposed in the past two decades; however, most of them focus on untripped rollover prevention instead of the tripped rollovers. Up to now, very few pieces of literature discuss the approaches that are used to avoid tripped rollovers of trucks. Furthermore, the air suspension is widely used for commercial vehicles, thus it provides an opportunity to prevent rollovers when properly manipulated. Therefore, a novel tripped rollover prevention system is proposed for trucks at low-speed operations with air suspensions. A roll dynamics model with an air spring is built to investigate the dynamic behavior and the time response of the whole system. More importantly, the feasibility of this new anti-rollover system is discussed and verified by the co-simulations in TruckSim and MATLAB/Simulink under two possible tripped rollover conditions.

Sensor Anomaly Detection and Recovery in the Roll Dynamics of a Delta-Wing Aircraft via Monte Carlo and Maximum Likelihood Methods

This paper studies the problem of sensor anomaly detection, estimation and recovery for the roll dynamic model of a generic delta-wing aircraft. The proposed algorithm employs particle filtering and maximum likelihood methods to detect and estimate the anomaly. The estimated anomaly is then used to correct the sensor readings. It is assumed that both the system model and sensor outputs are corrupted by noise, which are not necessarily Gaussian. Simulation results are presented to show the performance of the proposed algorithm.

ИДЕНТИФИКАЦИЯ ДИНАМИКИ КАНАЛА КРЕНА БЕСПИЛОТНОГО ЛЕТАТЕЛЬНОГО АППАРАТА ПРИ СЛАБО ИНФОРМАТИВНОМ ВХОДНОМ СИГНАЛЕ

In this article has been identified linear stationary roll dynamic model for unmanned air vehicle with the weak exciting input signal and sensor measurements noise using the two-step method, maximum likelihood method and the genetic optimization algorithm. Due to the weak frequency content of the input signal, eigenvalues of the information matrix are close to zero, and the use of the output error method often gives the wrong solutions in each cycle of the identification algorithm based on the Monte Carlo method. Ill-conditioned information matrix in the identification of dynamic model occurs due to linear relationships between variables. The two-step identification method finds the ratio of the parameters in the first stage. In the second step, the identification algorithm is conducted for the vector of parameters with reduced size. The two-stage identification method gives the right solution with the permissible errors for each execution of the identification process

Compactly modelling and analysing the roll dynamics of a partly filled tank truck

In this study, a compact roll dynamics model for a partly filled tank truck is formulated based on Lagrange's approach. A trammel pendulum equivalent mechanical model is used to simulate the fluid lateral sloshing, and the nonlinear stiffness property of the suspension is also taken into account. The model is indirectly validated by comparing the state response with Salem's trammel pendulum model (Salem et al., 2009). The analysis results reveal that the lateral fluid sloshing in a partly filled tank generally couples with the body roll dynamics of the vehicle, and the rollover stability threshold can be enhanced by increasing the vehicle suspension stiffness. It is concluded that there is a potential of optimising the parameters of tank-sectional shape, suspension stiffness and damping, and some other configurable parameters to elevate the rollover stability of a partly filled tank truck in a wide fill level range.

Single propeller airplane minimal flight speed based upon the lateral maneuver condition

This paper presents the application of the previously presented general analysis method to determine the safe flight boundaries of the asymmetrically loaded airplane within the terminal flight phases as applied to the case of inherently asymmetric single propeller airplane. As the lateral control surface design is done for the flight conditions out of the terminal flight phases, the key objective is to improve the flight safety of the asymmetrically loaded airplane by introducing the lateral flight controls verification at the low flight speeds. The concept of the authority of control surfaces presenting their capability to generate the forces and moments needed by the airplane to perform required maneuvers is the basis of the analysis. Control surface authority is the function of the control surface aerodynamic properties, structurally available flight control displacements and dynamic pressure. The analysis method scope is based upon the requirement to supplement the safe flight boundaries of symmetrically loaded airplane within the terminal flight phases, with the lift coefficient observed as the function of the angle of attack being at the linear limit. Control surface demands are lateral maneuver execution and asymmetric load and lateral wind compensation, the method scope permitting them to be addictive. Thus defined, the method is based upon the comparison of the available control surface authority and demands. For the defined flight conditions, the analysis is reduced to the comparison of the demanded and structurally available flight control displacement. The method combines the simple roll dynamics model, the stationary equations of the airplane lateral-directional motion and several numeric analysis procedures to obtain the results. This new combination possesses synergy properties and is implemented as the computer program. The method is applicable for any combination of airplane asymmetric loads and can be used throughout entire airplane life cycle. The contemporary trend of downsizing training and light combat airplane types with the rising number of the introduced medium and high power single propeller airplane types increases the significance of the method application in the design procedure.

Model-Based Estimation for Vehicle Dynamics States at the Limit Handling

This technical brief proposes a new model-based estimation method for the vehicle sideslip angle, yaw rate, roll angle, and roll rate using unscented Kalman filter (UKF). Since a vehicle wheel could potentially lift off the ground during the limit handling, a switched vehicle roll dynamics model (wheel lift and no wheel lift) is developed and integrated within the proposed model-based estimation approach considering the availability of wheel speed sensor. The simulation results and analyses demonstrate the performance enhancement of the proposed estimation method over the method not considering wheel lift during the limit handling.

Smooth Sliding Mode Control for Vehicle Rollover Prevention Using Active Antiroll Suspension

The rollover accidents induced by severe maneuvers are very dangerous and mostly happen to vehicles with elevated center of gravity, such as heavy-duty trucks and pickup trucks. Unfortunately, it is hard for drivers of those vehicles to predict and prevent the trend of the maneuver-induced (untripped) rollover ahead of time. In this study, a lateral load transfer ratio which reflects the load distribution of left and right tires is used to indicate the rollover criticality. An antiroll controller is designed with smooth sliding mode control technique for vehicles, in which an active antiroll suspension is installed. A simplified second order roll dynamic model with additive sector bounded uncertainties is used for control design, followed by robust stability analysis. Combined with the vehicle dynamics simulation package TruckSim, MATLAB/Simulink is used for simulating experiment. The results show that the applied controller can improve the roll stability under some typical steering maneuvers, such as Fishhook and J-turn. This direct antiroll control method could be more effective for untripped rollover prevention when driver deceleration or steering is too late. It could also be extended to handle tripped rollovers.

Robust Vehicle Roll Dynamics Identification based on Roll Rate Measurements

The modern vehicle development process is required to provide short product update cycles and high cost efficiency. Nonetheless, the demands on vehicle safety and handling quality remain high as ever. Driving characteristics evaluation relies on extensive subjective assessment as well as objective methods. Model-based objective assessment saves time and costs as most of the evaluation work can be done offline, i.e. during or after a test run the parameters of a vehicle dynamics model are identified and used for later simulation work. Referring to vehicle dynamics assessment the roll movement of the vehicle is of great importance (aside from longitudinal and lateral vehicle dynamics).This paper presents two methods for the online parameter identification of a simple roll dynamics model. These parameters can then be used for computation of the roll angle. The first method employs a recursive least-squares algorithm whereas the second method consists of a sliding-mode observer combined with an uncertainty reconstruction technique. Compared to other existing methods for vehicle roll dynamics identification both estimation techniques only require the cost-efficiently measurable roll rate and lateral acceleration signals.

Characterisation of pavement profile heights using accelerometer readings and a combinatorial optimisation technique

Pavement surface profiles induce dynamic ride responses in vehicles which can potentially be used to classify road surface roughness. A novel method is proposed for the characterisation of pavement roughness through an analysis of vehicle accelerations. A combinatorial optimisation technique is applied to the determination of pavement profile heights based on measured accelerations at and above the vehicle axle. Such an approach, using low-cost inertial sensors, would provide an inexpensive alternative to the costly laser-based profile measurement vehicles. The concept is numerically validated using a half-car roll dynamic model to infer measurements of road profiles in both the left and right wheel paths.

Vehicle stability control system for enhancing steerabilty, lateral stability, and roll stability

The Vehicle stability control system is an active safety system designed to prevent accidents from occurring and to stabilize dynamic maneuvers of a vehicle by generating an artificial yaw moment using differential brakes. In this paper, in order to enhance vehicle steerability, lateral stability, and roll stability, each reference yaw rate is designed and combined into a target yaw rate depending on the driving situation. A yaw rate controller is designed to track the target yaw rate based on sliding mode control theory. To generate the total yaw moment required from the proposed yaw rate controller, each brake pressure is properly distributed with effective control wheel decision. Estimators are developed to identify the roll angle and body sideslip angle of a vehicle based on the simplified roll dynamics model and parameter adaptation approach. The performance of the proposed vehicle stability control system and estimation algorithms is verified with simulation results and experimental results.

DEVELOPMENT OF A ROLL DYNAMICS MODEL OF A LIQUID TANK VEHICLE

The roll dynamics model of a liquid tank vehicle is developed by integrating an equivalent mechanical analogy model of the liquid cargo to the roll plane model of a heavy commercial vehicle. The mechanical analogy model of the fluid slosh is represented through an equivalent pendulum system derived from the potential flow theory for a cylindrical tank. The non-linear vehicle model equations are derived in the roll plane of the tank vehicle by the use of Lagrang’s equations. The fluid-vehicle interaction is hence dynamically coupled in order to investigate the directional behavior of the tank vehicle during typical highway maneuvers. Computer simulations are performed on the dynamic roll model of the tank vehicle under various fill conditions and dynamic maneuver conditions. The roll response of the tank vehicle is then compared to that of an equivalent rigid cargo vehicle to study the impact of fluid slosh behavior. The influence of fluid fill level, loading conditions and vehicle characteristics on the dynamic roll performance of the vehicle is also investigated.