基于时空特征融合的Encoder-Decoder多步4D短期航迹预测
Multi-step 4D Short-term Trajectory Prediction Using Encoder-Decoder with Spatio-Temporal Features Fusion
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摘要: 航迹预测在确保空中交通安全、高效运行中扮演着至关重要的角色。所预测的航迹信息是航迹优化、冲突告警等决策工具的输入,而预测准确性取决于模型对航迹序列特征的提取能力。航迹序列数据是具有丰富时空特征的多维时间序列,其中每个变量都呈现出长短期的时间变化模式,并且这些变量之间还存在着相互依赖的空间信息。为了充分提取这种时空特征,本文提出了基于融合时空特征的编码器-解码器(Spatio-Temporal Encoder-Decoder, STED)航迹预测模型。在Encoder中使用门控循环单元(Gated Recurrent Unit, GRU)、卷积神经网络(Convolutional Neural Network, CNN)和注意力机制(Attention, AT)构成的双通道网络来分别提取航迹时空特征,Decoder对时空特征进行拼接融合,并利用GRU对融合特征进行学习和递归输出,实现对未来多步航迹信息的预测。利用真实的航迹数据对算法性能进行验证,实验结果表明,所提STED网络模型能够在未来10 min预测范围内进行高精度的短期航迹预测,相比于LSTM、CNN-LSTM和AT-LSTM等数据驱动航迹预测模型具有更高的精度。此外,STED网络模型预测一个航迹点平均耗时为0.002 s,具有良好的实时性。Abstract: The trajectory prediction plays a crucial role in ensuring the safety and efficient operation of air traffic. The predicted trajectory information serves as input for decision-making tools such as trajectory optimization and conflict alerts, and the accuracy of prediction depends on the model’s ability to extract features from the trajectory sequence. The trajectory sequence data is a multidimensional time series with rich spatio-temporal characteristics, where each variable exhibits long-term and short-term temporal patterns, and there are also spatial dependencies among these variables. To fully capture these spatio-temporal features, this paper proposes an Encoder-Decoder model based on the fusion of spatio-temporal features, referred to as the Spatio-Temporal Encoder-Decoder (STED) model. In the Encoder, a dual-channel network consisting of gated recurrent unit (GRU), convolutional neural network (CNN), and attention mechanisms (AT) is employed to separately extract the spatio-temporal features of the trajectory. The Decoder concatenates and fuses the spatio-temporal features, and utilizes GRU to learn and recursively output the fused features, thereby achieving multi-step prediction of future trajectory information. The performance of the algorithm is validated using real trajectory data. Experimental results demonstrate that the proposed STED network model achieves high accuracy in short-term trajectory prediction within a prediction range of 10 minutes. It outperforms data-driven trajectory prediction models such as LSTM, CNN-LSTM, and AT-LSTM in terms of accuracy. Furthermore, the STED network model predicts a trajectory point with an average time consumption of 0.002 seconds, demonstrating excellent real-time performance.