Author: Tian Zhen, SAIC Volkswagen mobile Internet business infrastructure and application development, senior architect.
The Internet of Vehicles is to establish the connection between vehicles and vehicles, vehicles and people, and vehicles and roads through the "cloud pipe terminal" technology, and realize in-vehicle information services, vehicle control automation and intelligent transportation. Data interaction with T-Box and car-machine system through the Internet of Vehicles platform is also one of the main forms of intelligent interaction of the Internet of Vehicles. The Volkswagen Group has been paying attention to car-machine systems very early. The first-generation MIB, which came out in 2013, initially showed the embryonic form of the car-networking in terms of networking. From the first generation to the third generation, MIB iterated rapidly and reached the leading level at the time. However, the key point that smart cars are truly different from traditional cars is scalability. The ability to connect to the cloud and infinitely extend functions by downloading APP is the most essential feature of smart cars, and it is also the general trend of car development. In order to keep up with the trend of the times, SAIC Volkswagen launched a new intelligent vehicle linkage system in 2020, with the new MOS vehicle-machine system, which is first mounted on the latest Passat model. This is also the rare focus of the Volkswagen brand in the past two years. Field exploration.
From 2018, when SAIC Volkswagen was designing and developing a new generation of Internet of Vehicles systems, the SC department took into account the large concurrency, low latency, and high throughput of the new Internet of Vehicles. It referred to the mainstream new Internet of Vehicles system architecture at home and abroad and adopted MQTT- based Agreement to build a new generation of car networking platform. The new Internet of Vehicles platform needs to be able to support the development of the Internet of Vehicles of SAIC Volkswagen in the next few years. This requires the MQTT message middleware in the platform to have the ability to support the connection and data transmission of the Internet of Vehicles from millions to tens of millions. The business covers vehicle data reporting, POI issuance, file push, configuration issuance, message push, operation care and other vehicle networking business support.
In the process of building a new platform to select MQTT message middleware, the SC department mainly considered the following functional and performance requirements:
Functional aspect
Need to fully support the MQTT v3.1.1 protocol, and can support the complete MQTT v5.0 protocol in the later stage . For the scenarios of SAIC Volkswagen in the application of Internet of Vehicles, the following functions need to be supported:
- Support the data reported by the car and machine can be persisted on the platform to ensure that the data is not lost;
- In the POI delivery scenario, it supports the platform to know whether the vehicle has received the feedback information of the message; the platform provides a buffer for POI delivery data, and can set the POI cache time to ensure that the delivered message is not lost when the vehicle is offline , The message will be sent automatically after going online;
- Support the platform to push files, configuration push to the car and machine, and support broadcast push.
- In terms of security, devices are supported for security authentication through certificates, and device connections support TLS1.2; for illegally connected to the platform, the client can be authenticated and controlled, and the platform can also close illegal connections through API.
Performance
The following capabilities are required:
- It has the ability to support distributed architecture and horizontal expansion, and supports cluster deployment; clusters have high availability capabilities, support automatic node discovery, automatic clustering, automatic split brain healing, and automatic deletion of down nodes;
- In terms of performance indicators: on a Linux operating system with 16 cores and 32G memory, the number of connections for a single node is not less than 500,000; the total number of connections for a single cluster is not less than 10 million;
- Considering that in the actual scenario, each vehicle will have one or more platform unique topics, and it needs to support tens of millions of topics;
Deployment aspect
It is necessary to provide the ability to deploy in the private cloud environment of SAIC Volkswagen and support the deployment of docker containers to facilitate subsequent unified deployment and maintenance of the micro-service nodes of the overall system.
Operation and maintenance
It is necessary to provide a comprehensive monitoring system and support the export and integration of monitoring data. The monitoring indicators need to include the overall business indicator monitoring of the cluster, including the number of connections, the number of messages, the number of topics, the message throughput, etc.; the node system monitoring information includes the node's CPU, memory, network, disk I/O, and internal indicators of the virtual machine;
Taking into account the above requirements, after more than a year of comparative analysis and functional performance testing of a large number of different products, SAIC Volkswagen chose EMQ X Enterprise as the Internet of Things MQTT messaging middleware for the new generation of Internet of Vehicles access platform.
Architecture diagram of SAIC Volkswagen Internet of Vehicles access platform
As a well-known open source MQTT messaging middleware project, EMQ X provides T-box and mobile devices with a secure and stable access capability of millions to tens of millions and low-latency data processing capabilities. The Internet of Vehicles access layer solution based on EMQ X Enterprise provides functions including data persistence, southbound message caching, secure connection and security authentication , and meets the needs of SAIC Volkswagen in the construction of a new generation of Internet of Vehicles.
SAIC Volkswagen Internet of Vehicles access platform operation and maintenance monitoring dashboard
This year, SAIC Volkswagen's next-generation Internet of Vehicles platform has been launched, and more new models have been connected. The total number of vehicles connected to the platform has now reached hundreds of thousands and is still growing. The platform has always maintained a stable operating state. So far, the business needs of SAIC Volkswagen's new Internet of Vehicles and new car-machine systems at the access layer have been basically met with the help of EMQ X. On this basis, SAIC Volkswagen is also actively investigating based on the built-in rule engine and codec capabilities provided in the new version of EMQ X, and is considering implementing more business rule filtering and distribution at the message middleware layer to provide better solutions for the development of upper-layer applications. Convenient data interface.
In the future, SAIC Volkswagen’s next-generation Internet of Vehicles platform will continue to connect with other gasoline vehicles and new energy vehicles under the brand to provide more intelligent and convenient human-vehicle interaction experience for SAIC-Volkswagen customers, and create a new generation of human-vehicle social interaction. platform.
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Original link: https://www.emqx.io/cn/blog/emqx-in-volkswagen-iov