Roll Angle Of Body Research Articles

Dynamic Performance Optimization of Monorail Rapid Transit Formation Vehicles Based on Improved Artificial Potential Field Algorithm

This paper presents a new type of monorail rapid transit vehicle, which can operate in formation. In order to optimize the dynamic performance of the formation vehic-les when passing through the small radius curve, this paper first analyzes the structure of the new monorail rapid transit vehicle, and establishes the vehicle dynamic model and multi-body dynamics simulation model. Then the improved artificial potential field algorithm is used to build the formation vehicle operation controller. Finally, the dynamic performance evaluation index of the new mono-rail rapid transit formation vehicle is formulated, and the formation vehicle passing through the small radius curve scene is simulated. The simulation results show that the controller of the formation vehicle with dynamic optimi-zation control can effectively optimize the load transfer coefficient of running wheels, unbalanced centrifugal acce-leration and roll angle of vehicle body when passing thro-ugh the curve. Through this control method, the dynamic performance of formation vehicles passing through small radius curve lines can be optimized.

A Spring Compensation Method for a Low-Cost Biped Robot Based on Whole Body Control.

At present, the research and application of biped robots is more and more popular. The popularity of biped robots can be better promoted by improving the motion performance of low-cost biped robots. In this paper, the method of the Linear Quadratic Regulator (LQR) is used to track a robot's center of mass (COM). At the same time, the whole-body-control method and value function generated in the process of tracking COM are used to construct the quadratic programming (QP) model of a biped robot. Through the above method, the torque feedforward of the robot is obtained in the Drake simulation platform. The torque feedforward information of the robot is transformed into position feedforward information by spring compensation. In this paper, open loop control and spring compensation are used, respectively, to make the robot perform simple actions. Generally, after the compensation method of spring compensation is adopted, the roll angle and pitch angle of the upper body of the robot are closer to 0 after the robot performs an action. However, as the selected motion can introduce more forward and lateral motions, the robot needs more spring clearance compensation to improve performance. For improving the motion performance of a low-cost biped robot, the experimental results show that the spring compensation method is both reasonable and effective.

Development of a Fuzzy Algorithm With Multiple Inputs for the Active Stabilizer Bar to Improve Vehicle Stability When Steering

In this article, the author discusses the issue of vehicle roll instability when steering at high speeds. Installing an active stabilizer bar in a car is recommended to prevent it from rolling over and make it more stable when it does. A complex dynamic model is set up to evaluate and analyze vehicle oscillations. Besides, a fuzzy algorithm with three independent inputs is used to control the operation of the active stabilizer bar. This algorithm uses three separate inputs derived from the vehicle’s oscillating signals. In addition, the membership function and fuzzy rule are designed to ensure that the quality and efficiency of the system are well-maintained and stable. This is an entirely new method, which is rarely used for complex models of cars. Numerical simulation is carried out in a Simulink environment with many specific cases and situations. According to research findings, the roll angle of the vehicle body increases as the speed increases. This causes a greater change in wheel dynamics force and increases the risk of rollover. If the car is equipped with an active stabilizer bar controlled by the fuzzy algorithm with three inputs, these problems are significantly reduced compared to all other situations. So, when this new algorithm is added to the active stabilizer bar, the car’s stability and safety can improve even.

A complex rollover dynamics model with active stabilizer bar controlled by the fuzzy algorithm

The active stabilizer bar is used to improve the vehicle's safety when steering at high speeds. In this paper, the spatial dynamics model and nonlinear double-track dynamics model are used to simulate vehicle oscillations. Besides, the nonlinear tire model is also used. This is a completely novel and complex model. Besides, the fuzzy control algorithm is used to control the active stabilizer bar. This algorithm uses two input signals, which are obtained from the simulation. The membership function and fuzzy rules are designed optimally based on the results of many previous simulations and calculations. The simulation process is performed by MATLAB-Simulink software with three specific cases. The results of the paper show that the roll angle of the vehicle body and the change in vertical force at the wheel are significantly reduced when the vehicle uses the active stabilizer bar controlled by the fuzzy algorithm. The rollover phenomenon has been significantly improved in all the investigated cases, corresponding to three specific speeds. The stability and responsiveness of the controller are very high. The fuzzy algorithm can be combined with some other algorithms to improve system efficiency.

Modeling and simulation of energy harvesting hydraulically interconnected shock absorber

Ride comfort, road handling and fuel efficiency of a vehicle have always been crucial factors during vehicle shock absorber design. This paper proposes and studies a novel energy harvesting hydraulically interconnected shock absorber (EH-HISA) system to improve energy harvesting and ride comfort. A comparison study is done for the dynamic responses and power harvested by the vehicle equipped with EH-HISA and previous design for energy-harvesting hydraulically interconnected suspension (EH-HIS). In addition, the EH-HISA consists of two energy harvesting units compared to four energy harvesting units in EH-HIS, thus reducing the cost and weight of the overall system. A full car model is set up in AMESim to simulate the vehicle over a C class road. The comparison indicates that EH-HISA shows 11% reduction in lateral acceleration of car body center of gravity, during double lane change test over EH-HIS. While the peak roll angle of the vehicle body shows almost similar results of 1.4 degrees for EH-HISA and 1.2 degrees for EH-HIS. The average energy harvested for EH-HISA reaches a maximum value of 230 W and shows an improvement of 222 % over EH-HIS for the same road conditions and vehicle parameters.

Study on the Rut Control Threshold of Asphalt Pavement Considering Steering Stability of Autonomous Vehicles Based on Fuzzy Control Theory

To fully consider the impact of asphalt pavement rut on steering stability of autonomous vehicles, the sensitivity of various indicators of rut shape to vehicle stability was comprehensively measured, and pavement rut control standards based on comfort demands of autonomous vehicles were investigated. Firstly, a steering control system for autonomous vehicles was built in Simulink according to fuzzy control theory. Then, through orthogonal experiment design theory, different rut shape indicators are simulated in CarSim. The influence sensitivity of different rut shape indicators and the allowable rut range considering driving comfort were studied. The results show that both the rut depth and the rut side angle have a greater effect on the vehicle vertical acceleration within a certain parameter range. The maximum roll angle of vehicle body is mainly affected by the rut depth, and the rut width has a small effect on the vehicle driving stability. Meanwhile, considering human comfort, the rut side angle should not be greater than 1° when the rut depth reaches 2 cm. For autonomous driving, the rut depth should not exceed 2.5 cm. When the rut depth exceeds 2.5 cm, the vehicle body roll angle caused by the rut exceeds the inertial centrifugal force of the vehicle itself, which has a significant impact on the passenger comfort and safety.

Body attitude control strategy based on road level for heavy rescue vehicles

This paper proposes an attitude control strategy based on road level for heavy rescue vehicles. The strategy aims to address the problem of poor ride comfort and stability of heavy rescue vehicles in complex road conditions. Firstly, with the pressure of the suspension hydraulic cylinder chamber without a piston rod as the parameter, Takagi–Sugeno fuzzy controller classification and adaptive network-based fuzzy inference system controller classification are used to recognise the road level. Secondly, particle swarm optimisation is adopted to obtain the optimal parameters of the active suspension system of vehicle body attitude control under different road levels. Lastly, the parameters of the active suspension system are selected in accordance with the road level recognised in the driving process to improve the adaptive adjustment capability of the active suspension system at different road levels. Test results show that the root mean square values of vertical acceleration, pitch angle and roll angle of the vehicle body are reduced by 59.9%, 76.2% and 68.4%, respectively. This reduction improves the ride comfort and stability of heavy rescue vehicles in complex road conditions.

Using an LQR active anti-roll bar system to improve road safety of tractor semi-trailers

Introduction: Tractor semi-trailer vehicles are playing an increasingly important role in the global freight chain. However, due to the heavy total load and height of the center of gravity, this type of vehicle is often at a higher risk of instability than other vehicles. This paper focuses on improving the vehicle roll stability by using an active anti-roll bar system.
 Methods: The Linear Quadratic Regulator (LQR) approach is used for this purpose with the control signal being the torque generated by the active anti-roll bar system. In order to synthesize the controller, the roll angle of the vehicle body and the normalized load transfer at all axles of the tractor semi-trailer vehicle are considered as the optimal goals.
 Results: The simulation results in time and frequency domains clearly show the effectiveness of the proposed method for the active anti-roll bar system, because the reduction of the desired criterias is about 40% less when compared to a vehicle using the passive anti-roll bar system.
 Conclusions: The effectiveness of the active anti-roll bar system on improving the vehicle roll stability, has been verified in this theoretical study with the LQR optimal controller. This is an important basis for conducting more in-depth studies and future experiments.

Simulation and modelling of flight missile dynamics and autopilot analysis

In the current paper, nonlinear modelling and dynamical analysis of a surface to surface missile with both aerodynamic and thrust vector control is investigated. Aerodynamic force and moment modelling of the presented missile includes the challenging high angle of attack aerodynamics behaviour and the so-called hybrid control, which utilizes both tail fins for stabilization and rudder vanes as control surfaces. Then, concerning relative rotation between bodies, the missile aerodynamic model is built by Leabedev aerodynamic calculations software. After using the generated aerodynamic data obtained the required aerodynamic stability derivatives, the required transfer functions are resolute based on the equations of motion of the missile. The missile dynamic motion in pitch and roll channel are analysed. The guidance and control strategy are developed through an actuation system and autopilot design in the four channels based on the poles assignment technique. The roll autopilot is constructed to regulate the roll angle of the front body of the missile which is the controlled part, for the command signals generated by the guidance laws both pitch and yaw autopilots are designed to realize. The guidance command is in the form of rate of change of flight path angles of the missile with time.

Influence of control strategy on stability of dual-spin projectiles with fixed canards

Abstract Existing literature has shown that the control force at the nose could cause dynamic instability for controlled projectiles. To lower the adverse impact on the dual-spin projectile with fixed canards under the premise of meeting guidance system requirements, the influence of control moment provided by a motor on the flight stability is analyzed in this paper. Firstly, the effect of the rolling movement on stability is analyzed based on the stability criterion derived using the Hurwitz stability theory. Secondly, the evaluation parameters combining the features of different control periods that could assess the variation of stability features after the motor torque are obtained. These effective formulas are used to indicate that, to reduce the flight instability risks, the stabilized rolling speed of roll speed keeping period should be as small as possible; the variation trend of motor torque during the rolling speed controlling period and the roll angle of the forward body during roll angle switching period are recommended corresponding to the projectile and trajectory characteristics. Moreover, detailed numerical simulations of 155 mm dual-spin projectile are satisfactory agreement with the theoretical results.

Coordinated Chassis Control Based on Vehicle Lateral Acceleration Using Fuzzy Logic Control

This paper presents an advanced coordination of integrated control system which consist of three different controllers namely Electronic Stability Control (ESC), Active Front Steering (AFS), and Active Suspension (AS) using Fuzzy Logic Control (FLC) in order to improve vehicle handling, cornering stability, and rollover prevention with anti-lock brakingsystem (ABS) to avoid wheel locking during generating differential braking by ESC control. Based on a well-developed and validated fourteen degrees of freedom full vehicle model with non-linear tire characteristics, a reference yaw-roll plane vehicle model is introduced to compare and therefore control the yaw rate, side slip angle, and roll angle of the vehicle body. For rollover prevention indices, the dynamic load transfer ratio is defined to check the effectiveness of the proposed controller. The Coordination chassis control is based on the lateral acceleration value as input to FLC, and the outputs are the increment factors to the three controllers varying from zero to one. Three membership functions are chosen to represent the lateral acceleration as input to the supervisor controller, to define the control authority for each actuator. The universe of discourse for each membership function is selected according to the study of the effect of eachcontroller stand alone in vehicle performance. The numerical modelling is carried out through the MATLAB / Simulink environment which suits the control and optimization process. Different standard test maneuvers namely J-turn,fishhook, and double lane change have been carried out by considering standard test maneuvers with different driving speeds. The simulation results are compared during three cases namely, the uncontrolled system, the combined controller, and the proposed coordinated controller. The results show a substantial improvement of the vehicle stability in terms ofvehicle lateral acceleration, side slip angle, yaw rate, roll angle, and the for the developed coordinated controller compared to combined controller or the conventional system without control.

Parametric Analysis of Ride Comfort for Tilting Railway Vehicles Running on Irregular Curved Tracks

The ride comfort of a tilting railway vehicle moving on curved tracks with rail irregularities is studied. Using the nonlinear creep model and Kalker's linear theory, the governing differential equations of motion for a tilting railway vehicle running on irregular tracks are first derived. The tilting railway vehicle is modeled by a 27 degree-of-freedom (DOF) car system, considering the lateral displacement, vertical displacement, roll angle and yaw angle of both the wheelsets and bogie frames, as well as the lateral displacement, roll angle and yaw angle of the car body. Based on the international standard ISO 2631-1, the effect of vehicle speed on the ride comfort index of the tilting vehicle is investigated for various tilting angles, using both linear and nonlinear creep models, and various radii of curved tracks, as well as for various suspension parameters. Finally, the ride comfort indices computed with rail irregularities are found to be higher than those with no rail irregularities, indicating that the effect of rail irregularities on the ride comfort of a tilting vehicle cannot be disregarded in practice.

Establishment and Simulation of Nonlinear Dynamic Model of Finished Automobile

This paper established the nonlinear dynamic model of finished automobile to study the influence of suspension structural parameters, automotive braking and steering on the vehicle driving comfort and handling stability. The simulation results show that in the vehicle steering process, the body roll changed indirectly the tire lateral force, which had the impacts of yaw and lateral movement, and the interaction between the suspension and steering between systems is very significant especially under condition of the uneven road excitation. When the peak of the tire steering angle increased, the roll angle of vehicle body became larger and larger, followed by the change of body posture and the deterioration of ride comfort. With the increase of the steering angle, the lateral acceleration of the vehicle became larger and larger, and even resulted in tire skidding, thus reducing the driving safety of the vehicle.

Structural Optimization of a Heavy-Duty Truck Based on a Virtual Prototype Model

A virtual prototype whole-body model was built for a tri-axial heavy-duty truck. Selecting the lateral acceleration, roll angle and yaw rate as the evaluation index, the sensitivity of wheelbase and track was analyzed and the coordinates of hard points were optimized. The Hunting behaviors of the optimized vehicle were discussed and compared with that of the original vehicle. It is shown that the roll angle, yaw rate and vertical acceleration of vehicle body and the vertical acceleration at the seat are reduced greatly after optimization. Thus the vehicle structural optimization improves both handling stability and ride comfort.

G150032 アイガモ農法用ロボットの開発 : 水田における自律移動の安定化

We have been developing a rice-duck farming robot. The robot has functions of cackling, wing flapping, and feeding for gathering and leading real ducks. Our previous research results showed that these functions effectively gather and lead real ducks for weed areas in a paddy field. The robot has a tilt sensor and an acceleration sensor for measuring pitch, roll, and yaw angles of the robot's body, and has a front view camera for autonomous locomotion control. We designed and implemented a pitch angle control system and a roll angle control system for the robot. By using the roll angle of the robot's body, control parameters for crawlers are revised for stabilization of autonomous locomotion. By using the pitch angle of the robot's body, pitch angle of the front view camera is revised for stabilization of appropriate image processing and autonomous locomotion. The stabilization of autonomous locomotion in marshy paddy fields was verified through experiments in an indoor rice paddy.

Hunting stability and derailment analysis of a car model of a railway vehicle system

Using a heuristic linear creep model, this article derives the governing differential equations of motion for a vehicle travelling on curved tracks. The vehicle is modelled by a 27-degrees-of-freedom (27-DOF) car system, with lateral and vertical displacement, roll and yaw angle of each wheelset and the bogie frames, as well as lateral displacement, and roll and yaw angle of the car body taken into consideration. To analyse the respective effects of major system parameters on vehicle dynamics, the 27-DOF system is reduced to a 14-DOF system by excluding designated subsets of the system parameters. The effects of suspension parameters of a vehicle on the critical hunting speeds were evaluated by the 14- and 27-DOF systems. The results obtained in this study, show that the critical hunting speeds derived using the 14-DOF system are generally higher than those obtained using the 27-DOF system. Additionally, the critical hunting speeds derived using the heuristic non-linear creep model are lower than those achieved using the linear creep model. The effects on derailment quotients of vehicle speeds are evaluated using both linear and non-linear creep models with various suspension parameters. Finally, the effects of vehicle speed on the derailment quotient for sharp curves and low vehicle speed are investigated and compared with both linear and non-linear creep models.

Self-tuning Control on Integrated System of EPS and SAS Based on Pole Placement

Entire vehicle multi-degree of freedom dynamic model of Semi-Active Suspension(SAS) and Electric Power Steering(EPS) integrated system including yaw, roll and pitching motion is established. Self-tuning integrated control strategy of SAS and EPS integrated system based on pole placement is designed, and approach of on-line identification which combines the pole placement method with least square parameter estimation method is constructed. To carry out the real-time control on system, based on the simulation calculation, the developed adjustable shock absorber and integrated system controller are installed in a certain mini car. Real vehicle road test is carried on, and the simulation results are in good agreement with the test ones. Moreover, under self-tuning integrated control based on pole placement, the peak value and standard deviation of vertical acceleration of centroid, roll angle of vehicle body, pitching angle, yaw angular velocity, side angle of centroid are then reduced, vehicle ride comfort, handling stability and attitude change of vehicle body are improved, entire vehicle overall performance is enhanced.

Condition Monitoring of Railway Track Using In-service Vehicle

This paper summarizes the development of a portable track-condition-monitoring system for easy installation on in-service vehicles. In this system, rail irregularities are estimated from the vertical and lateral acceleration of the car body. The roll angle of the car body, calculated using a rate gyroscope, is used to distinguish line irregularities from level irregularities. Rail corrugation is detected from cabin noise with spectral peak calculation. A GPS system and a map-matching algorithm are used to pinpoint the location of faults on tracks. Field test using in-service vehicle was carried out to evaluate the developed system. The results show that the condition of rail irregularity and rail corrugation can be estimated effectively.

Modeling and nonlinear hunting stability analysis of high-speed railway vehicle moving on curved tracks

A heuristic nonlinear creep model is used to derive the nonlinear coupled differential equations of motion of a high-speed railway vehicle traveling on a curved track. The vehicle dynamics are modeled using a 21 degree-of-freedom (21-DOF) system which takes account of the lateral displacement and yaw angle of each wheelset, the lateral displacement, vertical displacement, roll angle and yaw angle of the truck frames, and the lateral displacement, vertical displacement, roll angle, pitch angle and yaw angle of the car body. To analyze the respective effects of the major system parameters on the vehicle dynamics, the 21-DOF system is reduced to 20-DOF, 14-DOF and 6-DOF models, respectively, by excluding designated subsets of the system parameters. The validity of the analytical models and the numerical solution procedure is confirmed by comparing the result obtained using the 6-DOF model for the critical velocity of a railway vehicle traveling on a tangent track with the solution presented in the literature. In general, the results obtained in this study show that the critical hunting speed derived using the 6-DOF or 14-DOF model is generally higher than that evaluated using the 20-DOF model. In addition, the critical hunting speed evaluated via the heuristic nonlinear creep model is lower than that derived using a linear creep model.

345303 CONDITION MONITORING OF RAILWAY TRACK USING IN-SERVICE VEHICLE (Condition Monitoring,Technical Session)

This paper summarizes the development of a portable track-condition-monitoring system for easy installation on in-service vehicles. In this system, rail irregularities are estimated from the vertical and lateral acceleration of the car body. The roll angle of the car body, calculated using a rate gyroscope, is used to distinguish line irregularities from level irregularities. Rail corrugation is detected from cabin noise with spectral peak calculation. A GPS system and a map-matching algorithm are used to pinpoint the location of faults on tracks. Field test using in-service vehicle was carried out to evaluate the developed system. The results show that the condition of rail irregularity and rail corrugation can be estimated effectively.