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Autonomous Driving Technology for Connected Cars
The connected car is recognized for its potential as a platform for achieving a prosperous society in which people and vehicles exist in harmony. Hitachi is developing data center services and onboard devices for vehicles that combine automotive technology with IoT know-how acquired through past involvement in the information and communications sector. This article describes key technologies for building connected cars.
Connected cars with always-on links via the Internet to data centers and other infrastructure have attracted attention as a next generation of vehicles able to provide services that deliver greater safety and comfort. Because of their role as platforms for advanced driver assistance systems, including autonomous driving, connected cars need high levels of reliability and information processing capacity.
By combining know-how in automotive systems with information and communications technology acquired through involvement in a variety of product fields, Hitachi is developing a diverse range of center services and onboard devices to provide a platform for connected cars.
This article summarizes the trends and technical issues associated with connected systems, and describes key technologies for the wireless updating of software, security for protecting information, and in-vehicle edge computing.
The main services for connected cars in the 2000s were based on data analysis, with the provision of information on traffic congestion being a typical example. When first introduced, the service worked by implementing a communication module that can be connected to a mobile communication network in commercial vehicles such as taxis. These were called telematics control units (TCUs). Improvements to service convenience in recent years have seen vehicle manufacturers installing TCUs in cars as a standard feature to provide connected car services to the general public.
With Internet connections having become commonplace in vehicles, infotainment services have also spread, such as those that obtain information from social networking services (SNSs) and display it on the navigation system screen. Services have also emerged that provide a limited form of remote vehicle operation by issuing commands to the vehicle via a data center. Remote door unlocking is one example. It is likely that closer interoperation between data centers and vehicles, with various services using the results of analysis at a data center to provide feedback to vehicle control, will become commonplace (see left side of Figure 1). Security will be vital to implementing these feedback services, and Hitachi is working on the development of gateways for handling security in the vehicle.
Figure 1 - Roadmap and System Architecture for Connected Car Services The diagram on the left expresses the shift from data analysis and simple information distribution services to services that provide the results of analysis as feedback, while that on the right shows how TCUs, gateways, and IVI provide edge server functions for edge computing.
It is anticipated that future links between vehicles and data centers will have a system architecture like that shown on the right of Figure 1. Hitachi is working on the development of the underlying technologies that will make these systems possible. The data center will use Hitachi's Lumada Internet of Things (IoT) platform.
The following sections provide details of technologies for over-the-air (OTA) software updating, security, and in-vehicle edge computing that will be essential for building the platforms that support connected car solutions.
Recent years have seen a shift from hardware to software as the primary means of vehicle control, with the software on automotive electronic control units (ECUs) playing an increasingly important role. While this central role for software in control opens up new opportunities for the automotive industry, including the ability to provide after-sales upgrades, recalls due to software are also a major concern. The increasing number of connected cars also brings concerns about greater security risks such as the risk of remote attacks. One technology that has attracted attention as a way to deal with these changing circumstances is the use of wireless communications for controlling software updating by OTA.
The use of OTA updates for vehicles requires the following features. The first one is a high level of reliability to avoid vehicle problems such as software upgrades failing or impacting on safety. The second one is to shorten update times to avoid draining the battery while minimizing the period of time that vehicles are unavailable. The last one is to deal with diverse and complex systems made up of a large number of ECUs that behave differently.
Hitachi has developed the following techniques for utilizing OTA for automotive systems in a way that overcomes the above problems (see Figure 2) (1), (2).
Figure 2 - Block Diagram of OTA System Hitachi has developed a total system that extends from the data center system to the ECUs being updated, and identified the requirements for each function from a system perspective. For functional safety and security, control ECU updating is managed by a gateway. Standardized technologies are used for the interfaces between the data center and vehicle and between the onboard ECUs to enable a multi-supplier system to be configured.
Hitachi has developed TCUs, gateways, ECUs, and data center systems that incorporate these techniques, with the intention of supplying a one-stop OTA solution made up of these components and systems.
Software updating must be suitable not only for vehicles that are already in the marketplace; it also needs to work for components that are still in the development, manufacturing (production line), or distribution (ports or vehicle storage yards) processes of vehicle manufacturers, or in the manufacturing, distribution, or storage processes of parts suppliers.
The aims for the future are to boost the efficiency of software updating and management across the entire lifecycle, facilitate recalls, and improve traceability by coordinating vehicle identification and software/device management by the software updating system with product lifecycle management (PLM) and manufacturing execution systems (MESs) (see Figure 3).
Figure 3 - OTA in Development and Manufacturing Processes As for after-sales upgrades, the use of wireless communications to update software during development and manufacturing makes the work more efficient.
As vehicles become more connected, networks that previously did not extend beyond the vehicle itself are now being connected to the Internet and other external networks. This has led to concerns about attacks on vehicles from these external networks, raising the issue of how to reduce security risks such as unauthorized remote operation or interception of communications between a vehicle and data center.
Hitachi sees gateways as being a key component of the next generation of vehicles. In addition to acting as a router for communication between different network domains in a vehicle, these gateways are also equipped with functions for maintaining security within the vehicle by monitoring its internal communications, and the security of interoperation with the security operation center to improve quality and security through the lifecycle of the vehicle.
The gateway is implemented with the following security functions to protect against the internal and external threats to the vehicle identified by threat analysis. The gateway uses these security functions to prevent external attacks from gaining access to onboard networks.
Security requires countermeasures not just against anticipated attacks but also against forms of attack that are becoming increasingly sophisticated. Along with the security measures provided at the time of development, this also calls for the monitoring of vehicles in the field to provide a quick response to any issues that arise.
The following security solutions for interoperation with a security operation center maintain security through the lifecycle of the vehicle.
Figure 4 - Key Management Solution Hitachi supplies a key management solution that handles everything from generation to use of the keys needed for authentication and encryption in connected services and between onboard ECUs, anticipating all aspects from vehicle manufacture to use.
It is anticipated that the amount of data collected from each vehicle will grow considerably in the future due to functions such as the security log analysis service described above. As more cars become connected, this increasing volume of data communications will become an issue. Accordingly, Hitachi believes that future platforms for the connected car will require functions like the following for reducing data volumes.
This is the same principle as used by edge computing on the IoT, minimizing the amount of data collected from the vehicle while still maintaining service quality.
Statistical processing functions that operate based on these data collection rules run on the gateway that collects sensor and log data from the various ECUs. However, because this gateway is an embedded system that also handles other functions, including security and routing, it suffers from a lack of central processing unit (CPU), memory, and other resources. For this reason, Hitachi has developed in-vehicle edge computing technology that can run on resource-limited hardware (see Figure 6).
Figure 6 - Edge Computing Platform Based on Script Distribution The platform combines ease of program updating with a low processing load by using low-overhead compiled code for core statistical operations but using script to specify how those statistical operations are to be combined.
This technology provides a way to modify rules on onboard devices and uses a mix of script and compiled code to reduce resource use by these devices. While script typically makes program changes easier because no compilation is required, it also requires more CPU and memory resources to execute. Compiled code, in contrast, uses fewer resources, but is more difficult to modify because of the need for compilation when making program changes. In response, Hitachi succeeded in achieving both ease of modification and low resource use by using the following two programming languages.
Changes to rules can be implemented immediately by sending a script file containing the new rules from the data center to the gateway and overwriting the old script file.
This article has described platform technologies that Hitachi is developing for connected cars.
By supplying solutions that combine TCUs, gateways, and other onboard devices; OTA software updating, security, and other data center services; and computing techniques for the pre-processing of large amounts of information on the vehicle, Hitachi intends to help provide society with smart mobility that brings prosperity as well as harmony between people and vehicles with greater safety and comfort.