Optimal lateral control for autonomous vehicle based on multi-stage handling inverse dynamics

2021 ◽  
pp. 095440702098628
Author(s):  
Xinglong Zhang ◽  
Youqun Zhao ◽  
Wenxin Zhang ◽  
Fen Lin
Keyword(s):  
Inverse Dynamics ◽  
Control Method ◽  
Autonomous Vehicle ◽  
Pseudospectral Method ◽  
Dynamics Model ◽  
Lateral Control ◽  
State Variable ◽  
Multi Stage ◽  
Driving Task ◽  
Inverse Dynamics Problem

In this paper, an optimal lateral control method for autonomous vehicle based on multi-stage handling inverse dynamics is proposed. By applying this method, the vehicle can be controlled to complete the corresponding driving task without tracking a certain ideal state variable trajectory. Firstly, a separate-stage handling inverse dynamics problem is described; and by setting the connections between each stage, a multi-stage handling inverse dynamics model is developed; then we convert the inverse dynamics problem into an optimal control problem (OCP). Secondly, an improved hp-adaptive Radau pseudospectral method ( hp-RPM) is applied to discrete the continuous OCP; and then the sequential quadratic programming is used to solve the problem. In addition, the results of contrast verification show that, when solving non-smooth problem, the improved hp-RPM has higher computational efficiency than hp-RPM. Finally, simulations under three typical cases and bench tests illustrate the effectiveness of the proposed method.

The human-like trajectory planning for autonomous vehicles based on optimal control in a test track environment

2021 ◽  
pp. 095440702110090
Author(s):  
Xing Xu ◽  
Minglei Li ◽  
Feng Wang ◽  
Ju Xie ◽  
Xiaohan Wu ◽  
...  
Keyword(s):  
Optimal Control ◽  
Autonomous Vehicles ◽  
Optimal Trajectory ◽  
Control Method ◽  
Autonomous Vehicle ◽  
Trajectory Data ◽  
Test Track ◽  
Optimal Control Method ◽  
The Future ◽  
On The Road

A human-like trajectory could give a safe and comfortable feeling for the occupants in an autonomous vehicle especially in corners. The research of this paper focuses on planning a human-like trajectory along a section road on a test track using optimal control method that could reflect natural driving behaviour considering the sense of natural and comfortable for the passengers, which could improve the acceptability of driverless vehicles in the future. A mass point vehicle dynamic model is modelled in the curvilinear coordinate system, then an optimal trajectory is generated by using an optimal control method. The optimal control problem is formulated and then solved by using the Matlab tool GPOPS-II. Trials are carried out on a test track, and the tested data are collected and processed, then the trajectory data in different corners are obtained. Different TLCs calculations are derived and applied to different track sections. After that, the human driver’s trajectories and the optimal line are compared to see the correlation using TLC methods. The results show that the optimal trajectory shows a similar trend with human’s trajectories to some extent when driving through a corner although it is not so perfectly aligned with the tested trajectories, which could conform with people’s driving intuition and improve the occupants’ comfort when driving in a corner. This could improve the acceptability of AVs in the automotive market in the future. The driver tends to move to the outside of the lane gradually after passing the apex when driving in corners on the road with hard-lines on both sides.

scholarly journals Normal form approach in the motion planning of space robots: a case study

2021 ◽  
Author(s):  
Krzysztof Tchoń ◽  
Katarzyna Zadarnowska
Keyword(s):  
Normal Form ◽  
Motion Planning ◽  
Normal Forms ◽  
Inverse Dynamics ◽  
Planning Problem ◽  
Inverse Dynamics Problem ◽  
Velocity Level ◽  
Form Approach ◽  
Space Approach

AbstractWe examine applicability of normal forms of non-holonomic robotic systems to the problem of motion planning. A case study is analyzed of a planar, free-floating space robot consisting of a mobile base equipped with an on-board manipulator. It is assumed that during the robot’s motion its conserved angular momentum is zero. The motion planning problem is first solved at velocity level, and then torques at the joints are found as a solution of an inverse dynamics problem. A novelty of this paper lies in using the chained normal form of the robot’s dynamics and corresponding feedback transformations for motion planning at the velocity level. Two basic cases are studied, depending on the position of mounting point of the on-board manipulator. Comprehensive computational results are presented, and compared with the results provided by the Endogenous Configuration Space Approach. Advantages and limitations of applying normal forms for robot motion planning are discussed.

scholarly journals Adaptive Smart Control Method for Electric Vehicle Wireless Charging System

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2685 ◽  
Author(s):  
Lingbing Gong ◽  
Chunyan Xiao ◽  
Bin Cao ◽  
Yuliang Zhou
Keyword(s):  
Control System ◽  
Control Method ◽  
Characteristic Curve ◽  
Constant Current ◽  
Voltage Source ◽  
Wireless Charging ◽  
Charging Time ◽  
Multi Stage ◽  
Smart Charging ◽  
Smart Control

In order to shorten the wireless charging time of electric vehicles (EVs) and achieve stable charging, an adaptive smart control method for EV wireless charging is proposed in the paper. The method dynamically tracks the rechargeable battery state during the whole charging process, realizes multi-stage charging of constant current (CC) or constant voltage (CV) by switching two kinds of compensation networks of bilateral L3C and L3C-C, and regulates the charging voltage and current to make it as close as possible to the battery charging characteristic curve. This method can be implemented because the voltage source connected to the coupler and the compensation networks of bilateral L3C and L3C-C have the CC and CV source characteristics, respectively. On the basis of the established adaptive smart control system of EV wireless charging, the experiments of wireless data transmission and adaptive smart charging were conducted. The results showed that the designed control system had a response time of less than 200 ms and strong anti-interference ability and it shortened the charging time by about 16% compared with the time using traditional charging methods, thereby achieving a fast, stable, safe, and complete wireless charging process.

Static optimal estimation of joint accelerations for inverse dynamics problem solution

2002 ◽  
Vol 35 (11) ◽  
pp. 1507-1513 ◽  
Author(s):  
Violaine Cahouët ◽  
Martin Luc ◽  
Amarantini David
Keyword(s):  
Inverse Dynamics ◽  
Optimal Estimation ◽  
Problem Solution ◽  
Inverse Dynamics Problem

scholarly journals Research on Multi-Stage Composite Loading Process Control Method for Roller Staking of Self-Lubricating Spherical Plain Bearings

2021 ◽  
Vol 11 (23) ◽  
pp. 11127
Author(s):  
Qiang Wang ◽  
Jigang Chen ◽  
Haili Zhou ◽  
Xiaokang Wang ◽  
Zhanqi Hu
Keyword(s):  
Process Control ◽  
Control Method ◽  
Groove Depth ◽  
Material Damage ◽  
Technical Standards ◽  
Deformation Degree ◽  
Loading Process ◽  
Time Control ◽  
Multi Stage

The staking quality of Self-lubricating Spherical Plain Bearings (SSPBs) directly affects the safety of aircraft and the service life of bearings. Reliable loading process control methods and precise process parameter indexes will come into the creation of efficacious staking quality. Therefore, this paper aims to analyze the mechanical state of the roller staking process and give a load control method and corresponding parameter indexes for the high-quality roller staking process. First, based on the analysis of quality inspection requirements, five states of the deformation degree of the flanging lip of the V groove during the roller staking process were proposed, and their relationship with the requirements was studied. Then, the mechanical states corresponding to the five deformation states of the flanging lip deformation were obtained by numerical simulation, and the feeding displacement was determined. Meanwhile, a Multi-Stage Composite Loading (MSCL) process control method was first proposed to control the material damage of the flanging lip, i.e., the rotate speed of the roller tool was constant during the roller staking process, and the displacement–time control was adopted first; when the staking load reaches a staking value, the force–time control was used to make the staking quality meet the requirements. Finally, the staking quality of the MSCL method was verified though the test. The research shows that the feeding displacement needs to be added to the requirements, and the recommended value is 0.5–0.6 times of the V groove depth. A good surface quality and non-material-damage of the flanging lip is more likely to be obtained by the MSCL process control method. The research reveals the formation mechanism of process deformation, and gives more precise process control indexes. At the same time, it provides a theoretical reference for more reliable technical standards.

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.

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