Abstract: The Internet of vehicles (IoV) is an important research area of the intelligent transportation systems using Internet of things theory. The complex event processing technology is a basic issue for processing the data stream in IoV, in which the spatial and temporal information is the character of the data stream of IoV, which is different from the classical ones in Internet of things. It is one of the core issues of the complex event processing technology in IoV, how to effectively represent and process these temporal and spatial information of the data stream. To solve this problem, this paper proposes a novel spatial-temporal complex event processing language (STEP) for the IoV. In STEP, time intervals are used to denote the temporal model and grid map is used to denote the spatial models. This paper firstly establishes the syntax of STEP based on the modified spatial-temporal relation operators, which can effectively express the spatial and temporal relationships of event instance stream of IoV. Then this paper defines the operational semantics of STEP language, and also designs the event instance stream processing algorithm based on the Petri net model. Finally, this paper uses some examples to demonstrate the effectiveness of the event stream processing mechanism based on STEP language.

Key words: Internet of things, Internet of vehicles, complex event processing, event processing language, formal  , semantics, spatial-temporal event stream

摘要： 车联网是物联网技术应用于智能交通领域所形成的重要研究领域。复杂事件处理技术是车联网系统数据流处理的重要方法。有别于经典的物联网系统，车联网中数据流包含大量的时间和空间信息。在复杂事件处理技术中，如何有效地表达和处理车联网的时空数据流成为亟待解决的问题。针对该问题，提出了一种时空事件处理语言（spatial-temporal event processing language，STEP）。STEP分别采用时间段和栅格地图作为时间和空间模型。基于该时空模型，首先给出STEP语言的相关时空算子和完整语法，从而有效地表达车联网中时空事件流的时空信息。然后，分别从形式语义学角度引入STEP语言的操作语义，并且从实现角度给出了基于Petri网模型的时空事件流处理算法，从而建立车联网时空事件流处理机制。最后，通过实验说明了基于STEP语言的车联网时空事件流处理机制的有效性。

关键词: 物联网, 车联网, 复杂事件处理, 事件处理语言, 形式语义, 时空事件流