Development of an Intermediate Degree of Freedom Vehicle Dynamics Model for Optimal Design Studies

2000 ◽  
Author(s):  
Erik M. Lowndes ◽  
J. W. David
Keyword(s):  
Optimal Design ◽  
Vehicle Dynamics ◽  
Control Algorithm ◽  
Three Dimensional ◽  
Dynamics Model ◽  
Design Studies ◽  
Vehicle Simulation ◽  
Race Car ◽  
Sufficient Detail ◽  
Intermediate Degree

Abstract Today’s race teams spend a significant amount of time and money performing on-track testing of their vehicles in order to determine the best possible suspension configuration for a particular racing venue. The use of computer simulation coupled with optimal design techniques presents the opportunity to significantly reduce the amount of on-track testing required. Many of the existing vehicle simulation codes are not suitable for application to the optimal design problem, either because they incorporate too much detail and run too slowly, or because they lack sufficient detail. A new model that bridges the gap between these two existing classes of models and is suitable for performing optimal design has been developed. The vehicle model is fully three dimensional and nonlinear. A driver control algorithm was developed that is capable of driving the car near it’s handling limits. An attempt was made to optimize the suspension setup for the NCSU Legends race car.

Off-Road Vehicle Dynamics Mobility Simulation With a Compaction Based Deformable Terrain Model

2013 ◽  
Author(s):  
Justin Madsen ◽  
Andrew Seidl ◽  
Dan Negrut
Keyword(s):  
Vehicle Dynamics ◽  
Transfer Functions ◽  
Soil Mechanics ◽  
Three Dimensional ◽  
Interaction Model ◽  
Simulation Software ◽  
Repeated Loading ◽  
Model Parameters ◽  
Vehicle Simulation ◽  
Terrain Model

This paper discusses the terramechanics models developed to incorporate a physics-based, three dimensional deformable terrain database model with vehicle dynamics mobility simulation software. The vehicle model is contained in Chrono, a research-grade C++ based Application Programming Interface (API) that enables accurate multibody simulations. The terrain database is also contained in a C++ based API, and includes a general tire-terrain interaction model which is modular to allow for any tire model that supports the Standard Tire Interface (STI) to operate on the terrain. Furthermore, the ability to handle arbitrary, three dimensional traction element geometry allows for tracked vehicles (or vehicle hulls) to also interact with the deformable terrain. The governing equations of the terrain are based on a soil compaction model that includes both the propagation of subsoil stresses due to vehicular loads, and the resulting visco-elastic-plastic stress/strain on the affected soil volume. Non-flat, non-homogenous and non-uniform soil densities, rutting, repeated loading and strain hardening effects are all captured in the vehicle mobility response as a result of the general 3-D tire/terrain model developed. Pedo-transfer functions allow for the calculation of the soil mechanics model parameters from existing soil measurements. This terrain model runs at near real-time speed, due to parallel CPU and GPU implementation. Results that exercise the force models developed with the 3-D tire geometry are presented and discussed for a kinematically driven tire and a full vehicle simulation.

scholarly journals A Three-Dimensional Integrated Non-Linear Coordinate Control Framework for Combined Yaw- and Roll-Stability Control during Tyre Blow-Out

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8328
Author(s):  
Boyuan Li ◽  
Chao Huang ◽  
Yang Wu ◽  
Bangji Zhang ◽  
Haiping Du
Keyword(s):  
Vehicle Dynamics ◽  
Degrees Of Freedom ◽  
Integrated Control ◽  
Three Dimensional ◽  
Stability Control ◽  
Control Mode ◽  
Level Control ◽  
Dynamics Model ◽  
Control Framework ◽  
Upper Level

A tyre blow-out can greatly affect vehicle stability and cause serious accidents. In the literature, however, studies on comprehensive three-dimensional vehicle dynamics modelling and stability control strategies in the event of a sudden tyre blow-out are seriously lacking. In this study, a comprehensive 14 degrees-of-freedom (DOF) vehicle dynamics model is first proposed to describe the vehicle yaw-plane and roll-plane dynamics performance after a tyre blow-out. Then, based on the proposed 14 DOF dynamics model, an integrated control framework for a combined yaw plane and roll-plane stability control is presented. This integrated control framework consists of a vehicle state predictor, an upper-level control mode supervisor and a lower-level 14 DOF model predictive controller (MPC). The state predictor is designed to predict the vehicle’s future states, and the upper-level control mode supervisor can use these future states to determine a suitable control mode. After that, based on the selected control mode, the lower-level MPC can control the individual driving actuator to achieve the combined yaw plane and roll plane control. Finally, a series of simulation tests are conducted to verify the effectiveness of the proposed control strategy.

Design of Non-Isothermal T-Shaped Microreactors with Engulfment Flow by Using a Simplified Model

2011 ◽  
Vol 396-398 ◽  
pp. 1033-1038
Author(s):  
Lin Wang ◽  
Shinya Kawamura ◽  
Osamu Tonomura ◽  
Shinji Hasebe
Keyword(s):  
Optimal Design ◽  
Three Dimensional ◽  
Product Yield ◽  
Driving Pressure ◽  
Dynamics Model ◽  
Design Problems ◽  
Computational Fluid Dynamics Model ◽  
Design Result ◽  
Considerable Concern

T-shaped microreactors (T-MRs) with engulfment flow can increase product yield but their high driving pressure is a considerable concern to engineers. Thus, it is important to design a T-MR that can give maximum product yield within a limitation on driving pressure. The use of computational fluid dynamics model is not practical for optimal design of T-MRs due to its heavy computational load. In this research, an extended pseudo three-dimensional lamellar model (eP3DLAM) is proposed as a simple model of non-isothermal T-MRs to efficiently solve the optimal design problems. The usefulness of eP3DLAM is evaluated through a case study on T-MR design. The design result shows that eP3DLAM can accurately predict the concentration and temperature distributions in T-MRs and that the design period of T-MRs can be drastically reduced by using eP3DLAM.

Dynamic monitoring feedback iteration control for damping-adjustable semi-active suspension systems

2021 ◽  
pp. 1-9
Author(s):  
Chongchong Li ◽  
Jiangyong Xiong ◽  
Tingshan Liu ◽  
Ziang Zhang
Keyword(s):  
Root Mean Square ◽  
Working Conditions ◽  
Control Algorithm ◽  
Active Suspension ◽  
Dynamic Monitoring ◽  
Iteration Algorithm ◽  
Mean Square ◽  
Control Effect ◽  
Analytic Hierarchy ◽  
Vehicle Simulation

In order to further improve vehicle ride performance, a dynamic monitoring feedback iteration control algorithm is proposed by combining the features of a variable-damping semi-active suspension system and applying them to the system. A seven-degree-of-freedom finished vehicle simulation model is built based on MATLAB/Simulink. The root-mean-square values of the acceleration of the sprung mass, the dynamic travel of the suspension and the dynamic tire load are taken as evaluation indicators of vehicle ride performance. An analytic hierarchy process (AHP) is used to determine the weighting coefficients of the evaluation indicators, and a genetic algorithm is utilized to determine the optimal damping of the suspension under various typical working conditions. Suspension damping is controlled with a dynamic monitoring feedback iteration algorithm. The correction coefficients of the control algorithm are determined according to the deviation between the obtained damping and the optimized damping so that the control parameters will agree with the optimal result under typical working conditions, and the control effect under other working conditions is verified. The simulation results indicate that the proposed dynamic monitoring feedback iteration control algorithm can effectively reduce the root-mean-square value of the acceleration of the sprung mass by 10.56% and the root-mean-square value of the acceleration of the dynamic travel of the suspension by 11.98% under mixed working conditions, thus improving vehicle ride performance. The study in this paper provides a new attempt for damping control of semi-active suspension and lays a theoretical foundation for its application in engineering.

scholarly journals A Collision Dynamics Model of a Multi-Level Train

2006 ◽  
Author(s):  
Michelle Priante ◽  
David Tyrell ◽  
Benjamin Perlman
Keyword(s):  
Three Dimensional ◽  
Design Parameters ◽  
Collision Dynamics ◽  
Dynamics Model ◽  
Single Level ◽  
High Speeds ◽  
Front End ◽  
Multi Level ◽  
Low Speeds ◽  
Vertical Accelerations

In train collisions, multi-level rail passenger vehicles can deform in modes that are different from the behavior of single level cars. The deformation in single level cars usually occurs at the front end during a collision. In one particular incident, a cab car buckled laterally near the back end of the car. The buckling of the car caused both lateral and vertical accelerations, which led to unanticipated injuries to the occupants. A three-dimensional collision dynamics model of a multi-level passenger train has been developed to study the influence of multi-level design parameters and possible train configuration variations on the reactions of a multi-level car in a collision. This model can run multiple scenarios of a train collision. This paper investigates two hypotheses that could account for the unexpected mode of deformation. The first hypothesis emphasizes the non-symmetric resistance of a multi-level car to longitudinal loads. The structure is irregular since the stairwells, supports for tanks, and draglinks vary from side to side and end to end. Since one side is less strong, that side can crush more during a collision. The second hypothesis uses characteristics that are nearly symmetric on each side. Initial imperfections in train geometry induce eccentric loads on the vehicles. For both hypotheses, the deformation modes depend on the closing speed of the collision. When the characteristics are non-symmetric, and the load is applied in-line, two modes of deformation are seen. At low speeds, the couplers crush, and the cars saw-tooth buckle. At high speeds, the front end of the cab car crushes, and the cars remain in-line. If an offset load is applied, the back stairwell of the first coach car crushes unevenly, and the cars saw-tooth buckle. For the second hypothesis, the characteristics are symmetric. At low speeds, the couplers crush, and the cars remain in-line. At higher speeds, the front end crushes, and the cars remain in-line. If an offset load is applied to a car with symmetric characteristics, the cars will saw-tooth buckle.

scholarly journals Dynamic response analysis for multi-degrees-of-freedom parallel mechanisms with various types of three-dimensional clearance joints

2021 ◽  
Vol 18 (3) ◽  
pp. 172988142110177
Author(s):  
Jia Yonghao ◽  
Chen Xiulong
Keyword(s):  
Dynamic Response ◽  
Multibody Systems ◽  
Parallel Mechanism ◽  
Three Dimensional ◽  
Response Analysis ◽  
Parallel Mechanisms ◽  
Dynamics Model ◽  
Clearance Joints ◽  
Clearance Joint ◽  
Spatial Parallel Mechanism

For spatial multibody systems, the dynamic equations of multibody systems with compound clearance joints have a high level of nonlinearity. The coupling between different types of clearance joints may lead to abundant dynamic behavior. At present, the dynamic response analysis of the spatial parallel mechanism considering the three-dimensional (3D) compound clearance joint has not been reported. This work proposes a modeling method to investigate the influence of the 3D compound clearance joint on the dynamics characteristics of the spatial parallel mechanism. For this purpose, 3D kinematic models of spherical clearance joint and revolute joint with radial and axial clearances are derived. Contact force is described as normal contact and tangential friction and later introduced into the nonlinear dynamics model, which is established by the Lagrange multiplier technique and Jacobian of constraint matrix. The influences of compound clearance joint and initial misalignment of bearing axes on the system are analyzed. Furthermore, validation of dynamics model is evaluated by ADAMS and Newton–Euler method. This work provides an essential theoretical basis for studying the influences of 3D clearance joints on dynamic responses and nonlinear behavior of parallel mechanisms.

scholarly journals Computation of Three-Dimensional, Rotational Flow Through Turbomachinery Blade Rows for Improved Aerodynamic Design Studies

1986 ◽  
Author(s):  
S. V. Subramanian ◽  
R. Bozzola ◽  
Louis A. Povinelli
Keyword(s):  
Three Dimensional ◽  
Maximum Flow ◽  
Cost Effective ◽  
Computer Code ◽  
Integration Scheme ◽  
Aerodynamic Design ◽  
Design Studies ◽  
Flow Equations ◽  
Transonic Compressor ◽  
Numerical Predictions

The performance of a three dimensional computer code developed for predicting the flowfield in stationary and rotating turbomachinery blade rows is described in this study. The four stage Runge-Kutta numerical integration scheme is used for solving the governing flow equations and yields solution to the full, three dimensional, unsteady Euler equations in cylindrical coordinates. This method is fully explicit and uses the finite volume, time marching procedure. In order to demonstrate the accuracy and efficiency of the code, steady solutions were obtained for several cascade geometries under widely varying flow conditions. Computed flowfield results are presented for a fully subsonic turbine stator and a low aspect ratio, transonic compressor rotor blade under maximum flow and peak efficiency design conditions. Comparisons with Laser Anemometer measurements and other numerical predictions are also provided to illustrate that the present method predicts important flow features with good accuracy and can be used for cost effective aerodynamic design studies.

Application and Research of Digital Technology in Optimal Design of CNC Floor Boring and Milling Machine

2012 ◽  
Vol 429 ◽  
pp. 111-115
Author(s):  
Zhen Long Leng ◽  
Jin Feng Yang ◽  
Qun Ping Liu ◽  
Xun Deng
Keyword(s):  
Numerical Simulation ◽  
Optimal Design ◽  
Digital Technology ◽  
Three Dimensional ◽  
Milling Machine ◽  
Machine Model ◽  
Digital Modeling ◽  
Key Technologies ◽  
The Cost ◽  
Interference Checking

This paper focuses on application of the three-dimensional digital modeling, numerical analysis and optimization, digital control and other key technologies which provide technical support for the design and development in CNC floor boring and milling machine manufactruing. The three-dimensional digital modeling, digital assembly, interference checking help to eliminate some hidden trouble before processing and assembly. Numerical simulation reduces the cost and shortens the cycle of designand manufactruing in the optimal design of the machine. This technique has been successfully applied to a CNC Floor Boring and Milling Machine Model, which has been running for three years and achieved satisfactary economic result.

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