With the development of the automotive industry, cars are becoming heavier and faster. These changes not only place higher demands on the basic braking capabilities of vehicles but also pose greater challenges to vehicle stability. Studies on automotive safety show that approximately 10% of road accidents are caused by vehicles deviating from their intended path or skidding during braking. It is well known that improving the braking performance of the chassis is a crucial measure to reduce traffic accidents, and active intervention in braking is key to improving braking performance.
Although theoretical research on actively intervening in the braking system to improve vehicle stability began long ago, its practical implementation depended on technological advancements. The widespread application of hydraulic braking replacing traditional mechanical braking, and the development of electromechanical technology, provided the technical foundation for achieving active braking intervention and even made active drive and suspension intervention possible. Since then, from the initial Anti-lock Brake System (ABS) to today's Vehicle Dynamic Control (VDC) system, chassis electronic stability systems have embarked on a magnificent evolutionary path.
However, the evolution of chassis electronic stability systems has not stopped. The new E/E architecture of intelligent chassis brings new optimization directions for chassis electronic stability systems. For example, under the control of the chassis domain controller, various subsystems can work together to achieve faster stability control. The topic of intelligent chassis and electronic stability systems is becoming a research hotspot for mainstream automakers and suppliers.
Intelligent Chassis and Electronic Stability Systems
In today's wave of automotive electrification and intelligence, traditional power systems are being upgraded to three-electric systems, traditional mechanical components in the chassis system are being simplified, and the degree of electronic control is increasing. At the same time, with the increasing popularity of advanced driver-assistance systems (such as ACC and AEB) and the gradual implementation of autonomous driving systems, increasingly rich new demands for intelligent scenarios have emerged.
On the other hand, the consumer market's perception of automobiles is also changing. Terminal consumers no longer view cars solely as means of transportation; cars have become carriers and spaces that improve the quality of life. This consumer trend means that while the industry pursues automotive intelligence, it also needs to further improve the comfort and driving quality of cars, providing consumers with a more enjoyable driving experience.
Driven by this trend, automobiles are placing higher demands on chassis systems; a more intelligent chassis is needed to adapt to the development needs of automotive electrification and intelligence. The new requirements for intelligent chassis can be summarized into four categories:
Personalized: Providing personalized customization based on customer driving habits.
High Performance: More precise and faster system response.
Scalable: The system has self-learning capabilities and supports OTA upgrades.
High Security: Multiple security guarantees for product safety and information security.
Although the current market performance shows that chassis systems are still in the electromechanical hybrid stage, a trend towards intelligent chassis is already visible.
Firstly, there is the popularization and evolution of drive-by-wire technology in automobiles. Drive-by-wire technology originated from aircraft control systems, which convert the pilot's control commands into electrical signals and transmit them directly to autonomous actuators via cables. The biggest advantage of drive-by-wire technology is its precise and rapid response, an advantage inherited in automotive drive-by-wire technology. Currently, various chassis control subsystems have basically implemented drive-by-wire.
With the evolution of autonomous driving, the role of the driver is weakened, and the functions of the steering wheel and pedals are gradually reduced. The decoupling of the electronic control system and the driver's mechanical interface allows for more flexible adjustment of the chassis system characteristics, thus meeting the personalized needs of different customers. This is another advantage of drive-by-wire chassis.
Secondly, the transformation of intelligent driving system E/E architecture has also driven the evolution of intelligent chassis E/E architecture. In the electromechanical hybrid stage, the E/E architecture of the chassis system was a simple superposition of subsystem ECUs. Although there was cooperation between subsystems, this cooperation was only reflected at the information sharing level. Each subsystem still operated independently, and functional control was constrained by each other, resulting in slow response and failing to achieve the "1+1>2" effect.
The performance of the Vehicle Dynamic Control (VDC) system is constrained by the limitations of the traditional E/E architecture. VDC relies on the state input of the steering system and braking system to determine whether the vehicle is prone to understeer or oversteer, and controls the yaw rate by correcting the braking force at the wheels to return the vehicle to a stable state. Although the steering system directly affects vehicle stability, VDC does not directly intervene in the steering angle control of the steering system. Therefore, the performance of the steering system in this process will have a real-time impact on the speed of stability adjustment, but its impact can only keep the braking system in a "remedial adjustment" cycle. In other words, the steering system cannot play an "active assistance" role in stability control. In the new E/E architecture based on chassis domain controllers, the core functions of intelligent control are concentrated within the domain controller, enabling real-time coordinated control of various subsystems with precise and rapid response, breaking down the barriers of simple functional superposition between subsystems.
For example, in the case of a VDC system, the domain controller can integrate vehicle status feedback from various subsystems and intervene in control before the vehicle reaches its dynamic stability limit, quickly correcting braking, steering, and even suspension. Compared to traditional control, this shifts from "remedial control" to "preventive control," making it not only safer but also more comfortable for the driver.
It is foreseeable that with the evolution of intelligent chassis systems, electronic stability systems will undergo a revolutionary transformation. The trends of this evolution are mainly "collaborative cooperation," "prevention instead of remediation," and "fast and precise control." At the same time, electronic stability systems will no longer be provided independently by a single supplier, but will become a complex system involving multiple controllers, and the degree of coordination between the various subsystems will directly determine the performance of the electronic stability system.
(Source: Sohu Auto)