The Design of a Control Coupled Observer for the Longitudinal Control of Autonomous Vehicles

1998 ◽  
Vol 120 (2) ◽  
pp. 288-289 ◽  
Author(s):  
Seibum Ben Choi
Keyword(s):  
Research Program ◽  
Autonomous Vehicles ◽  
Experimental Results ◽  
Phase Lag ◽  
Longitudinal Control

This paper presents a distance observer that was developed for the longitudinal control of autonomous vehicles. The observer is implemented on a platoon of test vehicles as part of the California PATH research program. The experimental results show that the observer filters out the sensing error very effectively without any noticeable phase lag.

scholarly journals End-to-End Automated Lane-Change Maneuvering Considering Driving Style Using a Deep Deterministic Policy Gradient Algorithm

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5443
Author(s):  
Hongyu Hu ◽  
Ziyang Lu ◽  
Qi Wang ◽  
Chengyuan Zheng
Keyword(s):  
Autonomous Vehicles ◽  
The State ◽  
Steering Wheel ◽  
Lane Change ◽  
Simulation Environment ◽  
Longitudinal Control ◽  
Driving Style ◽  
Lane Changing ◽  
Policy Gradient ◽  
End To End

Changing lanes while driving requires coordinating the lateral and longitudinal controls of a vehicle, considering its running state and the surrounding environment. Although the existing rule-based automated lane-changing method is simple, it is unsuitable for unpredictable scenarios encountered in practice. Therefore, using a deep deterministic policy gradient (DDPG) algorithm, we propose an end-to-end method for automated lane changing based on lidar data. The distance state information of the lane boundary and the surrounding vehicles obtained by the agent in a simulation environment is denoted as the state space for an automated lane-change problem based on reinforcement learning. The steering wheel angle and longitudinal acceleration are used as the action space, and both the state and action spaces are continuous. In terms of the reward function, avoiding collision and setting different expected lane-changing distances that represent different driving styles are considered for security, and the angular velocity of the steering wheel and jerk are considered for comfort. The minimum speed limit for lane changing and the control of the agent for a quick lane change are considered for efficiency. For a one-way two-lane road, a visual simulation environment scene is constructed using Pyglet. By comparing the lane-changing process tracks of two driving styles in a simplified traffic flow scene, we study the influence of driving style on the lane-changing process and lane-changing time. Through the training and adjustment of the combined lateral and longitudinal control of autonomous vehicles with different driving styles in complex traffic scenes, the vehicles could complete a series of driving tasks while considering driving-style differences. The experimental results show that autonomous vehicles can reflect the differences in the driving styles at the time of lane change at the same speed. Under the combined lateral and longitudinal control, the autonomous vehicles exhibit good robustness to different speeds and traffic density in different road sections. Thus, autonomous vehicles trained using the proposed method can learn an automated lane-changing policy while considering safety, comfort, and efficiency.

On the Cause of Regenerative Chatter Due to Workpiece Deflection

1974 ◽  
Vol 96 (1) ◽  
pp. 179-186 ◽  
Author(s):  
S. Kato ◽  
E. Marui
Keyword(s):  
Differential Equation ◽  
Experimental Results ◽  
Phase Lag ◽  
Chatter Vibration ◽  
Transient Vibration ◽  
Regenerative Chatter ◽  
Work Surface ◽  
Chatter Vibrations

The cause and the mechanism of regenerative chatter vibrations due to the deflection of workpiece occurring in machining metals are investigated experimentally. The regenerative chatter vibration is induced by the phase lag of the undulations in successive cutting. This means that small undulations initially produced on a work surface by the transient vibration of the workpiece become larger and the undulations extend over the whole work surface because a given amount of energy is available for exciting or maintaining the vibration owing to the phase lag of successive undulations. Then, a differential equation of chatter vibration is introduced based on the experimental results, and some remarks on the properties of chatter vibration are given.

Research on the Properties of the Concrete Filled Steel Tube Columns with CFRP Composite Materials

2010 ◽  
Vol 163-167 ◽  
pp. 3555-3559
Author(s):  
Wei Gu ◽  
Hong Nan Li
Keyword(s):  
Composite Materials ◽  
Research Program ◽  
Steel Tube ◽  
Experimental Results ◽  
Composite Tubes ◽  
Concrete Filled Steel Tube ◽  
Damage Area ◽  
Cfrp Composite ◽  
Axially Loaded ◽  
Strengthening Method

This paper presents a phase of the research program to determine the feasibility of a proposed CFRP retrofit method to strengthen the corroded concrete filled steel tube columns. This method is wrapping the corroded concrete filled steel tube column with CFRP material. Eight concrete filled steel tube columns were tested in the laboratory with four of them strengthened using the proposed technique. All specimens were notched in the center zone to simulate the loss of section due to corrosion the four of them were wrapped with CFRP composite tubes in the damage area. All specimens were axially loaded to failure while strain and displacement were measured to demonstrate the validity of this repair concept. This paper presents the experimental results and discusses the findings with preliminary conclusions on the feasibility of the proposed strengthening method.

scholarly journals General Tendencies of the Behaviour of Vegetables Developed in a Soil Contaminated with Heavy Metals

2020 ◽  
Vol 71 (2) ◽  
pp. 85-90 ◽  
Author(s):  
Augustina Pruteanu ◽  
Valentin Vladut ◽  
Petru Cardei ◽  
Despina Bordean
Keyword(s):  
Heavy Metals ◽  
Life Cycle ◽  
Mathematical Models ◽  
Research Program ◽  
Accumulation Rate ◽  
Experimental Results ◽  
Extensive Research Program ◽  
Rate Behaviour ◽  
Plant Behaviour

The paper presents experimental results obtained in the study of heavy metals transfer from soil to vegetables. The experiments for which the raw and statistically processed data are presented in this paper are preliminary experiments within an extensive research program of plant behaviour in soils contaminated with heavy metals. These experiments underlie the development of primary statistical mathematical models that are also presented in the paper. These experiments will also form the basis for far more consistent experiments that follow plants throughout the life cycle. The statistical mathematical models presented in this paper facilitate extracting important conclusions about how plants accumulate heavy metals as well as about the accumulation rate behaviour during experiments. Both experiments and mathematical models will form the basis of complex experiments and dynamic mathematical models in the next stage of research.

Prediction of Traffic Signal and Longitudinal Control Method for Autonomous Vehicles using V2X

2020 ◽  
Vol 30 (3) ◽  
pp. 173-180
Author(s):  
Suhyun Yoon ◽  
Hae Jun Jo ◽  
Seong Woo Kwak ◽  
Jae Cheon Lee ◽  
Ho Seung Lee
Keyword(s):  
Autonomous Vehicles ◽  
Control Method ◽  
Traffic Signal ◽  
Longitudinal Control

scholarly journals Evolving the Controller of Automated Steering of a Car in Slippery Road Conditions

Algorithms ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 108 ◽  
Author(s):  
Natalia Alekseeva ◽  
Ivan Tanev ◽  
Katsunori Shimohara
Keyword(s):  
Genetic Programming ◽  
Autonomous Vehicles ◽  
Pid Controller ◽  
Control Model ◽  
Servo Control ◽  
Experimental Results ◽  
Pd Controller ◽  
Quality Of Control ◽  
Computing Paradigm

The most important characteristics of autonomous vehicles are their safety and their ability to adapt to various traffic situations and road conditions. In our research, we focused on the development of controllers for automated steering of a realistically simulated car in slippery road conditions. We comparatively investigated three implementations of such controllers: a proportional-derivative (PD) controller built in accordance with the canonical servo-control model of steering, a PID controller as an extension of the servo-control, and a controller designed heuristically via the most versatile evolutionary computing paradigm: genetic programming (GP). The experimental results suggest that the controller evolved via GP offers the best quality of control of the car in all of the tested slippery (rainy, snowy, and icy) road conditions.

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