To provide a simulation system platform for designing and debugging a small autonomous underwater vehicle＇s （AUV） motion controller, a six-degree of freedom （6-DOF） dynamic model for AUV controlled by thruster an...To provide a simulation system platform for designing and debugging a small autonomous underwater vehicle＇s （AUV） motion controller, a six-degree of freedom （6-DOF） dynamic model for AUV controlled by thruster and fins with appendages is examined. Based on the dynamic model, a simulation system for the AUV＇s motion is established. The different kinds of typical motions are simulated to analyze the motion performance and the maneuverability of the AUV. In order to evaluate the influences of appendages on the motion performance of the AUV, simulations of the AUV with and without appendages are performed and compared. The results demonstrate the AUV has good maneuverability with and without appendages.展开更多
Next-generation vehicle control and future autonomous driving require further advances in vehicle dynamic state estimation. This article provides a concise review, along with the perspectives, of the recent developmen...Next-generation vehicle control and future autonomous driving require further advances in vehicle dynamic state estimation. This article provides a concise review, along with the perspectives, of the recent developments in the estimation of vehicle dynamic states. The definitions used in vehicle dynamic state estimation are first introduced, and alternative estimation structures are presented. Then, the sensor configuration schemes used to estimate vehicle velocity, sideslip angle, yaw rate and roll angle are presented. The vehicle models used for vehicle dynamic state estimation are further summarized, and representative estimation approaches are discussed. Future concerns and perspectives for vehicle dynamic state estimation are also discussed.展开更多
In order to evaluate the impact of off-road terrains on the ride comfort of construction vehicles,a nonlinear dynamic model of the construction vehicles interacting with the terrain deformations is established based o...In order to evaluate the impact of off-road terrains on the ride comfort of construction vehicles,a nonlinear dynamic model of the construction vehicles interacting with the terrain deformations is established based on Matlab/Simulink software.The weighted root mean square(RMS)acceleration responses and the power spectral density(PSD)acceleration responses of the driver s seat heave,the pitch and roll angle of the cab in the low-frequency region are chosen as objective functions under different operation conditions of the vehicle.The results show that the impact of off-road terrains on the driver s ride comfort and health is clear under various conditions of deformable terrains and range of vehicle velocities.In particular,the driver s ride comfort is greatly affected by a soil terrain while the comfortable shake of the driver is strongly affected by a sand terrain.In addition,when the vehicle travels on a poor soil terrain in the frequency range below 4 Hz,more resonance peaks of acceleration PSD responses occurred than that on a rigid road of ISO 2631-1 level C.Thus,the driver s health is significantly affected by the deformable terrain in a low-frequency range.展开更多
The armored cable used in a deep-sea remotely operated vehicle(ROV) may undergo large displacement motion when subjected to dynamic actions of ship heave motion and ocean current. A novel geometrically exact finite el...The armored cable used in a deep-sea remotely operated vehicle(ROV) may undergo large displacement motion when subjected to dynamic actions of ship heave motion and ocean current. A novel geometrically exact finite element model for two-dimensional dynamic analysis of armored cable is presented. This model accounts for the geometric nonlinearities of large displacement of the armored cable, and effects of axial load and bending stiffness. The governing equations are derived by consistent linearization and finite element discretization of the total weak form of the armored cable system, and solved by the Newmark time integration method. To make the solution procedure avoid falling into the local extreme points, a simple adaptive stepping strategy is proposed. The presented model is validated via actual measured data. Results for dynamic configurations, motion and tension of both ends of the armored cable, and resonance-zone are presented for two numerical cases, including the dynamic analysis under the case of only ship heave motion and the case of joint action of ship heave motion and ocean current. The dynamics analysis can provide important reference for the design or product selection of the armored cable in a deep-sea ROV system so as to improve the safety of its marine operation under the sea state of 4 or above.展开更多
This paper presents an extended model predictive control(MPC)scheme for implementing optimal path following of autonomous vehicles,which has multiple constraints and an integrated model of vehicle and road dynamics.Ro...This paper presents an extended model predictive control(MPC)scheme for implementing optimal path following of autonomous vehicles,which has multiple constraints and an integrated model of vehicle and road dynamics.Road curvature and inclination factors are used in the construction of the vehicle dynamic model to describe its lateral and roll dynamics accurately.Sideslip,rollover,and vehicle envelopes are used as multiple constraints in the MPC controller formulation.Then,an extended MPC method solved by differential evolution optimization algorithm is proposed to realize optimal smooth path following based on driving path features.Finally,simulation and real experiments are carried out to evaluate the feasibility and the effectiveness of the extended MPC scheme.Results indicate that the proposed method can obtain the smooth transition to follow the optimal drivable path and satisfy the lateral dynamic stability and environmental constraints,which can improve the path following quality for better ride comfort and road availability of autonomous vehicles.展开更多
The aim of this paper is to investigate the effect of vehicle dynamics control systems （VDCS） on both the collision of the vehicle body and the kinematic behaviour of the ve- hicle＇s occupant in case of offset fron...The aim of this paper is to investigate the effect of vehicle dynamics control systems （VDCS） on both the collision of the vehicle body and the kinematic behaviour of the ve- hicle＇s occupant in case of offset frontal vehicle-to-vehicle collision. A unique 6-degree-of- freedom （6-DOF） vehicle dynamics/crash mathematical model and a simplified lumped mass occupant model are developed. The first model is used to define the vehicle body crash parameters and it integrates a vehicle dynamics model with a vehicle front-end structure model. The second model aims to predict the effect of VDCS on the kinematics of the occupant. It is shown from the numerical simulations that the vehicle dynamics/crash response and occupant behaviour can be captured and analysed quickly and accurately. Yurthermore, it is shown that the VDCS can affect the crash characteristics positively and the occupant behaviour is improved.展开更多
In order to improve speed tracking accuracy and ensure longitudinal stability control in vehicles under conditions of parameter uncertainty and external interference,this study introduces a modified sliding mode contr...In order to improve speed tracking accuracy and ensure longitudinal stability control in vehicles under conditions of parameter uncertainty and external interference,this study introduces a modified sliding mode control(SMC)method.The proposed method replaces the reaching rate function in conventional SMC with a saturation function,which effectively reduces the chattering phenomenon in the control process.The longitudinal modified SMC method consists of two stages for both driving and braking control,designed according to the longitudinal vehicle dynamics model.Within the first stage,the control law determines the engine torque or brake torque;while the second stage oversees the modulation of throttle opening or brake pressure.To ensure a smooth transition between driving and braking modes,switching rules are defined predicated on predefined thresholds governing the driving or braking torque and speed errors.The stability of this control system is verified through Lyapunov stability analysis.To validate the effectiveness and practicality of the algorithm,simulations are performed using CarSim/Simulink,and experiments are conducted on a hybrid Lincoln MKZ.Results from both simulations and experiments demonstrate that the modified SMC method improves speed tracking accuracy and longitudinal control stability,even when dealing with rapidly changing speeds.Moreover,the algorithm exhibits a remarkable ability to resist external interference,making it a reliable solution for real-world applications.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.50909025
文摘To provide a simulation system platform for designing and debugging a small autonomous underwater vehicle＇s （AUV） motion controller, a six-degree of freedom （6-DOF） dynamic model for AUV controlled by thruster and fins with appendages is examined. Based on the dynamic model, a simulation system for the AUV＇s motion is established. The different kinds of typical motions are simulated to analyze the motion performance and the maneuverability of the AUV. In order to evaluate the influences of appendages on the motion performance of the AUV, simulations of the AUV with and without appendages are performed and compared. The results demonstrate the AUV has good maneuverability with and without appendages.
基金supported by the National Natural Science Foundation of China(61403158,61520106008)the Project of the Education Department of Jilin Province(2016-429)
文摘Next-generation vehicle control and future autonomous driving require further advances in vehicle dynamic state estimation. This article provides a concise review, along with the perspectives, of the recent developments in the estimation of vehicle dynamic states. The definitions used in vehicle dynamic state estimation are first introduced, and alternative estimation structures are presented. Then, the sensor configuration schemes used to estimate vehicle velocity, sideslip angle, yaw rate and roll angle are presented. The vehicle models used for vehicle dynamic state estimation are further summarized, and representative estimation approaches are discussed. Future concerns and perspectives for vehicle dynamic state estimation are also discussed.
基金The Science and Technology Support Program of Jiangsu Province(No.BE2014133)the Prospective Joint Research Program of Jiangsu Province(No.BY2014127-01)
文摘In order to evaluate the impact of off-road terrains on the ride comfort of construction vehicles,a nonlinear dynamic model of the construction vehicles interacting with the terrain deformations is established based on Matlab/Simulink software.The weighted root mean square(RMS)acceleration responses and the power spectral density(PSD)acceleration responses of the driver s seat heave,the pitch and roll angle of the cab in the low-frequency region are chosen as objective functions under different operation conditions of the vehicle.The results show that the impact of off-road terrains on the driver s ride comfort and health is clear under various conditions of deformable terrains and range of vehicle velocities.In particular,the driver s ride comfort is greatly affected by a soil terrain while the comfortable shake of the driver is strongly affected by a sand terrain.In addition,when the vehicle travels on a poor soil terrain in the frequency range below 4 Hz,more resonance peaks of acceleration PSD responses occurred than that on a rigid road of ISO 2631-1 level C.Thus,the driver s health is significantly affected by the deformable terrain in a low-frequency range.
基金Project(2008AA09Z201)supported by the National High Technology Research and Development Program of China
文摘The armored cable used in a deep-sea remotely operated vehicle(ROV) may undergo large displacement motion when subjected to dynamic actions of ship heave motion and ocean current. A novel geometrically exact finite element model for two-dimensional dynamic analysis of armored cable is presented. This model accounts for the geometric nonlinearities of large displacement of the armored cable, and effects of axial load and bending stiffness. The governing equations are derived by consistent linearization and finite element discretization of the total weak form of the armored cable system, and solved by the Newmark time integration method. To make the solution procedure avoid falling into the local extreme points, a simple adaptive stepping strategy is proposed. The presented model is validated via actual measured data. Results for dynamic configurations, motion and tension of both ends of the armored cable, and resonance-zone are presented for two numerical cases, including the dynamic analysis under the case of only ship heave motion and the case of joint action of ship heave motion and ocean current. The dynamics analysis can provide important reference for the design or product selection of the armored cable in a deep-sea ROV system so as to improve the safety of its marine operation under the sea state of 4 or above.
基金This work was funded by the National Natural Science Foundation of China(Grant No.52075461)the Key Project in Science and Technology Plan of Xiamen,China(Grant No.3502Z20201015)the Science and Technology Plan of Fujian Province of China(Grant No.2021H6019).
文摘This paper presents an extended model predictive control(MPC)scheme for implementing optimal path following of autonomous vehicles,which has multiple constraints and an integrated model of vehicle and road dynamics.Road curvature and inclination factors are used in the construction of the vehicle dynamic model to describe its lateral and roll dynamics accurately.Sideslip,rollover,and vehicle envelopes are used as multiple constraints in the MPC controller formulation.Then,an extended MPC method solved by differential evolution optimization algorithm is proposed to realize optimal smooth path following based on driving path features.Finally,simulation and real experiments are carried out to evaluate the feasibility and the effectiveness of the extended MPC scheme.Results indicate that the proposed method can obtain the smooth transition to follow the optimal drivable path and satisfy the lateral dynamic stability and environmental constraints,which can improve the path following quality for better ride comfort and road availability of autonomous vehicles.
基金the Egyptian government and the Faculty of Engineering,Ain Shams University for supporting this research
文摘The aim of this paper is to investigate the effect of vehicle dynamics control systems （VDCS） on both the collision of the vehicle body and the kinematic behaviour of the ve- hicle＇s occupant in case of offset frontal vehicle-to-vehicle collision. A unique 6-degree-of- freedom （6-DOF） vehicle dynamics/crash mathematical model and a simplified lumped mass occupant model are developed. The first model is used to define the vehicle body crash parameters and it integrates a vehicle dynamics model with a vehicle front-end structure model. The second model aims to predict the effect of VDCS on the kinematics of the occupant. It is shown from the numerical simulations that the vehicle dynamics/crash response and occupant behaviour can be captured and analysed quickly and accurately. Yurthermore, it is shown that the VDCS can affect the crash characteristics positively and the occupant behaviour is improved.
基金supported by Hunan Provincial Natural Science Foundation of China(2021JJ40086,2022JJ40059)National Natural Science Foundation of China(52172384,52202466)Young Elite Scientists Sponsorship Program by CAST(2022QNRC001).
文摘In order to improve speed tracking accuracy and ensure longitudinal stability control in vehicles under conditions of parameter uncertainty and external interference,this study introduces a modified sliding mode control(SMC)method.The proposed method replaces the reaching rate function in conventional SMC with a saturation function,which effectively reduces the chattering phenomenon in the control process.The longitudinal modified SMC method consists of two stages for both driving and braking control,designed according to the longitudinal vehicle dynamics model.Within the first stage,the control law determines the engine torque or brake torque;while the second stage oversees the modulation of throttle opening or brake pressure.To ensure a smooth transition between driving and braking modes,switching rules are defined predicated on predefined thresholds governing the driving or braking torque and speed errors.The stability of this control system is verified through Lyapunov stability analysis.To validate the effectiveness and practicality of the algorithm,simulations are performed using CarSim/Simulink,and experiments are conducted on a hybrid Lincoln MKZ.Results from both simulations and experiments demonstrate that the modified SMC method improves speed tracking accuracy and longitudinal control stability,even when dealing with rapidly changing speeds.Moreover,the algorithm exhibits a remarkable ability to resist external interference,making it a reliable solution for real-world applications.
