polynomial curve
Automatic driving lane change safety prediction model based on LSTM
Sun, Wenjian, Pan, Linying, Xu, Jingyu, Wan, Weixiang, Wang, Yong
Autonomous driving technology can improve traffic safety and reduce traffic accidents. In addition, it improves traffic flow, reduces congestion, saves energy and increases travel efficiency. In the relatively mature automatic driving technology, the automatic driving function is divided into several modules: perception, decision-making, planning and control, and a reasonable division of labor can improve the stability of the system. Therefore, autonomous vehicles need to have the ability to predict the trajectory of surrounding vehicles in order to make reasonable decision planning and safety measures to improve driving safety. By using deep learning method, a safety-sensitive deep learning model based on short term memory (LSTM) network is proposed. This model can alleviate the shortcomings of current automatic driving trajectory planning, and the output trajectory not only ensures high accuracy but also improves safety. The cell state simulation algorithm simulates the trackability of the trajectory generated by this model. The research results show that compared with the traditional model-based method, the trajectory prediction method based on LSTM network has obvious advantages in predicting the trajectory in the long time domain. The intention recognition module considering interactive information has higher prediction and accuracy, and the algorithm results show that the trajectory is very smooth based on the premise of safe prediction and efficient lane change. And autonomous vehicles can efficiently and safely complete lane changes.
Experiments on Generative AI-Powered Parametric Modeling and BIM for Architectural Design
Ko, Jaechang, Ajibefun, John, Yan, Wei
With the rapid advancement of technology, artificial intelligence (AI) and machine learning (ML) have been integrated into the design process, presenting new opportunities and challenges for architects and designers. However, the potential for AI, particularly language models like ChatGPT - a conversational AI model developed by OpenAI (Radford et al. 2021)- to transform the architectural design process has yet to be fully explored. This paper presents a new framework for architectural design that uses ChatGPT and AI-based ideation and visualization tools, Veras ("VERAS" 2023), to make the design process easier and create 3D geometric models, parametric models, and Building Information Models using natural language input. The proposed framework combines ChatGPT and Veras to generate and explore design ideas rapidly. Using natural language input, architects can communicate their design intentions more intuitively, allowing quicker iterations and reducing barriers associated with traditional design tools (Hsu, Yang, and Buehler 2022). Moreover, ChatGPT's ability to understand human design intentions helps to translate the input into Building Information Modeling (BIM) and parametric Generative AI-Powered Parametric Modeling and BIM for Architectural Design 1 models, highlighting the potential of the architectural design process.
Autonomous Slalom Maneuver Based on Expert Drivers' Behavior Using Convolutional Neural Network
Pashaki, Shafagh A., Nahvi, Ali, Ahmadi, Ahmad, Tavakoli, Sajad, Naeemi, Shahin, Shamchi, Salar H.
Lane changing and obstacle avoidance are one of the most important tasks in automated cars. To date, many algorithms have been suggested that are generally based on path trajectory or reinforcement learning approaches. Although these methods have been efficient, they are not able to accurately imitate a smooth path traveled by an expert driver. In this paper, a method is presented to mimic drivers' behavior using a convolutional neural network (CNN). First, seven features are extracted from a dataset gathered from four expert drivers in a driving simulator. Then, these features are converted from 1D arrays to 2D arrays and injected into a CNN. The CNN model computes the desired steering wheel angle and sends it to an adaptive PD controller. Finally, the control unit applies proper torque to the steering wheel. Results show that the CNN model can mimic the drivers' behavior with an R2-squared of 0.83. Also, the performance of the presented method was evaluated in the driving simulator for 17 trials, which avoided all traffic cones successfully. In some trials, the presented method performed a smoother maneuver compared to the expert drivers.
MINVO Basis: Finding Simplexes with Minimum Volume Enclosing Polynomial Curves
Tordesillas, Jesus, How, Jonathan P.
This paper studies the polynomial basis that generates the smallest $n$-simplex enclosing a given $n^{\text{th}}$-degree polynomial curve in $\mathbb{R}^n$. Although the Bernstein and B-Spline polynomial bases provide feasible solutions to this problem, the simplexes obtained by these bases are not the smallest possible, which leads to overly conservative results in many CAD (computer-aided design) applications. We first prove that the polynomial basis that solves this problem (MINVO basis) also solves for the $n^\text{th}$-degree polynomial curve with largest convex hull enclosed in a given $n$-simplex. Then, we present a formulation that is independent of the $n$-simplex or $n^{\text{th}}$-degree polynomial curve given. By using Sum-Of-Squares (SOS) programming, branch and bound, and moment relaxations, we obtain high-quality feasible solutions for any $n\in\mathbb{N}$, and prove (numerical) global optimality for $n=1,2,3$ and (numerical) local optimality for $n=4$. The results obtained for $n=3$ show that, for any given $3^{\text{rd}}$-degree polynomial curve in $\mathbb{R}^3$, the MINVO basis is able to obtain an enclosing simplex whose volume is $2.36$ and $254.9$ times smaller than the ones obtained by the Bernstein and B-Spline bases, respectively. When $n=7$, these ratios increase to $902.7$ and $2.997\cdot10^{21}$, respectively.