scholarly journals Minimum Time Approach to Emergency Collision Avoidance by Vehicle Handling Inverse Dynamics

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Wang Wei ◽  
Bei Shaoyi ◽  
Yang Hui ◽  
Wang Yongzhi ◽  
Zhang Lanchun
Keyword(s):  
Optimal Control ◽  
Collision Avoidance ◽  
High Speed ◽  
Inverse Dynamics ◽  
Avoidance Performance ◽  
Control Object ◽  
Minimum Time ◽  
Driving Safety ◽  
Multiple Shooting ◽  
Vehicle Handling

Vehicle driving safety is the urgent key problem to be solved of automobile independent development while encountering emergency collision avoidance with high speed. And it is also the premise and one of the necessary conditions of vehicle active safety. A new technique of vehicle handling inverse dynamics which can evaluate the emergency collision avoidance performance is proposed. Based on optimal control theory, the steering angle input and the traction/brake force imposed by driver are the control variables; the minimum time required to complete the fitting biker line change is the control object. By using the improved direct multiple shooting method, the optimal control problem is converted into a nonlinear programming problem that is then solved by means of the sequential quadratic programming. The simulation results show that the proposed method can solve the vehicle minimum time maneuver problem, and can compare the maneuverability of two different vehicles that complete fitting biker line change with the minimum time and the correctness of the model is verified through real vehicle test.

scholarly journals Modeling and simulation of minimum time-handling inverse dynamics of a vehicle

2018 ◽  
Vol 10 (7) ◽  
pp. 168781401878608 ◽  
Author(s):  
Li-Xia Zhang ◽  
Fu-Quan Pan ◽  
Hui Zhang ◽  
Ting Feng
Keyword(s):  
Degrees Of Freedom ◽  
Load Transfer ◽  
Inverse Dynamics ◽  
Longitudinal Velocity ◽  
Minimum Time ◽  
Multiple Shooting ◽  
Steering Wheel ◽  
Dynamics Model ◽  
Vehicle Handling ◽  
Simulation Results

The performance of a vehicle in minimum time handling is highly important for the safety of the vehicle. In this study, a vehicle motion state equation with 3 degrees of freedom was established on the basis of the lateral, yaw, and longitudinal motions of the vehicle. Equations on the linear tire and motion trajectory were established with consideration of longitudinal load transfer to establish the vehicle-handling dynamics model. Steering-wheel angle, driving force equation set, and yaw angle equation had been introduced to convert the vehicle-handling dynamics model into the vehicle-handling inverse dynamics model. By introducing performance index, control set, and several constraint conditions, an optimal control model of the vehicle minimum time handling was established, which was solved by improved direct multiple-shooting nonlinear programming method. A comparison of the simulation results of ADAMS/Car and MATLAB showed that both of the optimal routes input were in tangent with the road boundary. We can observe through the longitudinal velocity that the MATLAB simulation results are more similar to a straight line than that of the ADAMS/Car simulation results, which meet the psychological expectation of a driver. Thus, the inverse dynamics model on minimum time handling of the vehicle is reasonable and feasible.

Minimum time overtaking problem of vehicle handling inverse dynamics based on interval mathematics

2018 ◽  
Vol 233 (6) ◽  
pp. 1534-1545 ◽  
Author(s):  
Youqun Zhao ◽  
Wenxin Zhang ◽  
Xinglong Zhang ◽  
Fen Lin
Keyword(s):  
Inverse Dynamics ◽  
Age Groups ◽  
Pseudospectral Method ◽  
Unmanned Vehicles ◽  
Minimum Time ◽  
Vehicle Handling ◽  
Interval Mathematics ◽  
Interval Analysis Method ◽  
Driving Assistance ◽  
Driving Assistance System

To analyze the influence of uncertain factors on minimum time overtaking, interval mathematics is used to describe the uncertainties, and the overtaking safety distance is calculated using interval analysis method. In addition, vehicle handling inverse dynamics is proposed in this paper. In this method, the driver-handling input can be obtained without the modeling of driver. The optimal control problem is first converted into a nonlinear programming problem based on Gauss pseudospectral method. Then sequential quadratic programming is applied to get the solution. The simulation results show that the overtaking behavior will be significantly different, if the drivers’ age groups or vehicles’ braking system parameters are different. Besides, the influence of different drivers’ estimate time is critical. The subjective judgments of the drivers are considered in this paper to realize the user-friendly design. This method may provide a reference for the research of unmanned vehicles and driving assistance system.

Suspension Optimum Design Considering Tire and Vehicle Matching

2014 ◽  
Vol 496-500 ◽  
pp. 617-620
Author(s):  
Fan Bai ◽  
Kong Hui Guo ◽  
Dang Lu
Keyword(s):  
Optimum Design ◽  
Performance Index ◽  
High Speed ◽  
Objective Assessment ◽  
Driving Safety ◽  
Safety Index ◽  
Experiment Data ◽  
Evaluation Standards ◽  
Vehicle Handling ◽  
Running Performance

A method of suspension optimum design based on the tire and vehicle matching was introduced in this paper. Firstly, the vehicle handling stability evaluation standards considering tire matching with vehicle were determined by the subjective and objective assessment. Secondly, the quality, suspension kinematics and compliance characteristics and tire mechanics of prototype were tested. The vehicle model of prototype was built in Carsim with the corresponding experiment data. The model was verified by the results of the vehicle handling stability tests. Then a combination simulation platform was developed by making use of Isight, Matlab and Casim. Finally the optimal design of suspension kinematics and compliance characteristics and tire mechanics were conducted, taking straight running performance index, high-speed driving safety index and high-speed cornering performance index as the objective. The simulation results indicated that after optimization, the straight running performance and high-speed cornering performance of prototype could be improved.

scholarly journals Vehicle Optimal Velocity Curves for Minimum-Time Maneuver

2014 ◽  
Vol 6 ◽  
pp. 194868 ◽  
Author(s):  
Li-xia Zhang ◽  
Fu-quan Pan ◽  
Xiao-yuan Chen ◽  
Feng-yuan Wang ◽  
Jun Lu ◽  
...  
Keyword(s):  
Optimal Control ◽  
Inverse Dynamics ◽  
Minimum Time ◽  
Curvature Radius ◽  
Minimal Amount ◽  
Optimal Velocity ◽  
Moving Vehicles ◽  
New Perspective ◽  
Vehicle Travel Time ◽  
The Given

A problem in vehicle minimum-time maneuver is the assumption that a vehicle passes through a given path in a minimal amount of time without deviating from the boundary of the given path. Vehicle handling inverse dynamics provides a new perspective to solve such problem. Based on inverse dynamics, this paper transformed the problem of optimal vehicle velocity for minimum-time maneuver into that of optimal control with the objective function of minimum time. The path for minimum vehicle travel time and the optimal control model were established. The optimal velocity curves for three types of paths, namely, monotonically increasing path, monotonically decreasing path, and constant radius path, were analyzed. On this basis, the optimal velocity curves were solved for two kinds of concrete paths: a path of decreasing curvature radius followed by a path of increasing curvature radius and another path of increasing curvature radius followed by a path of decreasing curvature radius. Nine cases of possible optimal velocity curves were acquired. The optimal velocity curve of the given path, that is, a parabola followed by a semicircle, was obtained. Optimal velocity curves can be used as reference for vehicle minimum-time maneuver, which is an important issue for driver safety in fast-moving vehicles.

scholarly journals Visual Flight Rules-Based Collision Avoidance Systems for UAV Flying in Civil Aerospace

Robotics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 9 ◽  
Author(s):  
Hamid Alturbeh ◽  
James F. Whidborne
Keyword(s):  
Decision Making ◽  
Optimal Control ◽  
Optimal Control Problem ◽  
Control Problem ◽  
Real Time ◽  
Collision Avoidance ◽  
Inverse Dynamics ◽  
Guidance System ◽  
Visual Flight Rules ◽  
Decision Making System

The operation of Unmanned Aerial Vehicles (UAVs) in civil airspace is restricted by the aviation authorities, which require full compliance with regulations that apply for manned aircraft. This paper proposes control algorithms for a collision avoidance system that can be used as an advisory system or a guidance system for UAVs that are flying in civil airspace under visual flight rules. A decision-making system for collision avoidance is developed based on the rules of the air. The proposed architecture of the decision-making system is engineered to be implementable in both manned aircraft and UAVs to perform different tasks ranging from collision detection to a safe avoidance manoeuvre initiation. Avoidance manoeuvres that are compliant with the rules of the air are proposed based on pilot suggestions for a subset of possible collision scenarios. The proposed avoidance manoeuvres are parameterized using a geometric approach. An optimal collision avoidance algorithm is developed for real-time local trajectory planning. Essentially, a finite-horizon optimal control problem is periodically solved in real-time hence updating the aircraft trajectory to avoid obstacles and track a predefined trajectory. The optimal control problem is formulated in output space, and parameterized by using B-splines. Then the optimal designed outputs are mapped into control inputs of the system by using the inverse dynamics of a fixed wing aircraft.

A CAD Package for High-Speed Cam Design Based on Direct Multiple Shooting Optimal Control Techniques

2004 ◽  
Author(s):  
Sebastian Mennicke ◽  
Richard W. Longman ◽  
Meng-Sang Chew ◽  
Hans Georg Bock
Keyword(s):  
Optimal Control ◽  
High Speed ◽  
Optimality Criteria ◽  
Iterative Refinement ◽  
Valve Train ◽  
Design Stage ◽  
Multiple Shooting ◽  
Cam Design ◽  
Trade Offs ◽  
Highly Nonlinear

High-speed automotive valve train design requires realistic models of the valve train. However, this frequently results in highly nonlinear systems with discontinuities and constraints. Optimality criteria and trade-offs for the designs are frequently performed through a process of simulation and iterative refinement. This paper presents CamOE, a cam design optimization package based on direct multiple shooting optimal control theory, incorporating structured sequential quadratic programming. The code allows the designer to incorporate the constraints of importance and to consider and synthesize appropriate optimality criteria. This allows him or her to synthesize the cam profile at the design stage without resorting to a tedious trial-and-error design process. This paper presents CamOE as a software environment that permits rapid feedback to the designer through the process of numerical experiments in specifying criteria and constraints on the automotive valve train.

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