Author: Guo Weijie
Summary
In order to meet the ever-growing demand for connected, intelligent, electrified, and shared vehicles, the research and development of electronic and electrical architectures for commercial vehicles has received increasing attention. Based on this, research is carried out around intelligent networked vehicles, specifically related to the design of electronic and electrical architecture of commercial vehicles and active safety measures of electronic and electrical architecture, for the reference of industry insiders.
Affected by the ever-increasing complexity of automobiles and the increasing number of vehicle electronic controllers, the traditional way in which suppliers are responsible for electronic and electrical design has gradually been eliminated, and the design of electronic and electrical architectures in the pre-development stage has begun to attract the industry's attention. Combined with the characteristics of intelligent networked vehicles, it is necessary to carry out the design of intelligent networked electronic and electrical architecture in a targeted manner. This design must also make a good choice of active safety measures.
1 Electronic and electrical architecture design of commercial vehicles
1.1 Overall Design
The overall design of the electronic and electrical architecture of commercial vehicles consists of domain controllers, communication network architectures, electrical architectures, actuators, sensors, upper-layer application software, computing platforms, and operating systems. In-depth analysis shows that the central gateway is responsible for connecting the communication domain controller, smart cockpit domain controller, and autopilot domain controller, and there are power domain controllers and chassis domain controllers in the reserved state. Based on the vehicle Ethernet, the autonomous driving domain controller can be connected to lidar, camera, inertial navigation, redundant radar, and the connection with the side laser radar and millimeter wave radar uses the CAN bus; the smart cockpit domain controller and the seat controller, The volume adjustment panel and the power amplifier are connected based on the CAN bus. The seat adjustment motor, seat heater, seat ventilation motor and other actuators are driven by hard wires, and the sensors such as USB interface, WIFI antenna, and GPS antenna are also collected by hard wires. Complete, connect the central control display, head-up display, and instrument display using LVDS; the connection between the communication domain controller and the main driver's door module and the drive test unit is realized through the CAN bus, which is also responsible for the headlight actuator and the wiper motor , Data collection and control interaction of dome light.
In the electrical architecture design, the electric power steering system, automatic driving domain controller, electronic brakes, vehicle body stability system, camera, inertial navigation, laser radar, etc. provide dual power supply through the power distribution unit with dual power supply design, and at the same time physically isolate the dual power supply to ensure system security. It is also necessary to do a good job in electrical balance check and ground point distribution. The underlying hardware implements decision-making and processes data through the computing platform. The computing platform involves communication interface units, digital signal processing units, visual processing units, computing units, memory units, control units, and AI units. Through multivariate data processing, it can be used for functions such as automatic driving. provide support. The operating system is composed of device drivers, architecture code, inter-process communication, memory management, process management, network protocol, system application interface, etc. It is responsible for event scheduling and task management, and virtual machine monitoring programs can also be used. In terms of service communication, the operating system can also play an important role, such as providing services and data call support for steer-by-wire, brake-by-wire, and automatic driving, and software standardized modules that are easy to expand and use can be formed smoothly. Based on the bus transmission protocol, the communication network architecture can become a signal transmission channel for actuators, sensors, and domain controllers.
The analysis of the electronic architecture design around the three-layer architecture design of actuators, sensors in the domain, domain controller, and central gateway shows that the automatic driving control is in charge of the automatic driving domain controller, and the QNX system is used as the operating system; the communication domain controller adopts V2X Communication and 5G modules, which can communicate with road equipment and other vehicles, use the Linux system as the operating system; the upper-layer application development of the smart cockpit domain controller is completed based on the Android system, involving seat control, central control large screen, integrated instrumentation, etc. Interactive function; communication between domain controllers is realized through vehicle Ethernet. The three-layer communication network is composed of LIN bus (or CAN bus) and vehicle Ethernet. In order to meet the real-time requirements of data, media access control chooses time-sensitive network (TSN), Data clock synchronization can be guaranteed, and the application layer communication protocol design is oriented to scheduling services.
1.2 Functional domain division
In the division of the functional domain of the vehicle, it can be subdivided in combination with the domain controller, which is specifically divided into the power domain, automatic driving domain, chassis domain, intelligent network connection domain, and intelligent cockpit domain.
The power domain involves high-voltage energy management, battery management, front and rear motor control, torque control, charging management, thermal management and other functions, and the core controller is VCU. Select distributed control to integrate the torque control function, based on the charging state feedback of the charger. The VCU can calculate the charging time and charging current during the charging process, and during the running of the vehicle, based on the battery voltage, current, power and other information fed back by the BMS, the VCU can allocate the energy usage of the battery.
The autonomous driving domain involves functions such as seat belts/airbags, adaptive cruise control, active braking, lane keeping, automatic parking, and lane alignment. The autonomous driving domain controller is the core, responsible for the automatic driving algorithm control, combined with the surrounding environment information to achieve the optimal vehicle attitude, driving route and other target calculations to meet the needs of automatic driving.
The chassis domain involves functions such as suspension management, electronic parking, service brake, backup brake, electric power steering, and automatic driving response. Distributed control is selected, and functions such as suspension system and braking system are realized through bus signals. Responsible for assisting the Autopilot Domain Controller.
The intelligent network domain involves functions such as vehicle networking V2X, 5G external network communication, interior and exterior lighting, rearview mirror, wiper/washing, door lock control, etc. The above functions are mainly integrated in the communication domain controller, relying on 5G modules and V2X functions , fast data transmission and data interaction can be achieved smoothly, and the auxiliary information provided can better serve autonomous driving. At the same time, the integration of body electronic functions can save costs by reducing the number of controllers.
The smart cockpit domain involves functions such as digital instruments, central control large-screen interaction, rear entertainment control screen, AI interaction/voice recognition, seat ventilation, etc., and can control the smart cockpit, such as adjusting the seat position and angle based on the driver's needs.
2. Active safety measures for electronic and electrical architecture of commercial vehicles
2.1 Domain controller hardware solution
Based on the analysis of the above functional domain division, it can be found that the domain controller hardware solution has many advantages, including reducing bus length, reducing electronic components, improving computing power, simplifying network architecture, expanding storage space, and supporting advanced buses. The logic processing and operation in each domain can be realized through the domain control scheme, the high-speed president is responsible for the data interaction between the domains, and the domain controller is responsible for the classification and integration of functional domains. In order to implement a domain controller, two microcontrollers can be set up in the same ECU, and the two are respectively responsible for the operation of Linux applications (infotainment functions, high computing tasks such as AI algorithms), and the operation of simple applications (diagnostic communication, in-vehicle and other real-time programs), the connection between the two is realized based on the serial peripheral device interface. In the design of active safety measures, multi-sensor fusion technology is selected to form a high-safety overall sensor solution for autonomous driving.
The active safety measures involved in the hardware design of the communication domain controller also need to be paid attention to, such as the second set of early warning system based on the interaction between vehicles and vehicles, which can ensure driving safety when the automatic driving lidar fails, specifically involving forward collision warning , blind spot warning, reverse overtaking warning, vehicle out of control warning, abnormal vehicle warning and other application scenarios.
2.2 Electrical system hardware scheme
The electrical system hardware scheme involves dual power supply systems, vehicle electrical balance, and grounding points. To ensure the safety of the scheme, it is necessary to focus on the redundant protection design of the dual power supply system. In the design, the main power supply status is not only collected by the PDU power distribution unit, but also automatically The driving system controller can also diagnose its own main power supply status, which can ensure the normal operation of the automatic driving system under dual power supply, and the driving safety can naturally be better guaranteed.
Active safety measures are also intuitively reflected in the anti-interference grounding. The safety of automotive electrical appliances can be better guaranteed. The specific design chooses measures to reduce the impedance of the grounding wire. The main choice is the single-point parallel connection method for automotive electrical grounding.
3 Conclusion
The electronic and electrical architecture of commercial vehicles and the design of active safety measures have great practical significance. On this basis, the overall design, functional domain division, domain controller hardware scheme, electrical system hardware scheme and other contents involved in this paper provide a highly feasible design path for intelligent networked electronic and electrical architecture. In order to better meet the development needs of the automobile industry, the exploration of electronic and electrical architecture design based on regional computing platforms also needs to be paid attention to.
About the Author;
Guo Weijie , male , born in 1985 , chief engineer, mainly engaged in the design and development of electronic and electrical systems of light commercial vehicles.