With the accelerating transition towards vehicle intelligence and electrification, chassis brake-by-wire technology has become a pivotal element in the industry's transformation. Within this technological framework, innovation in braking systems is particularly critical. The One-box brake-by-wire system, as a highly integrated electro-hydraulic braking solution, is emerging as the mainstream choice for new energy vehicles and intelligent driving vehicles due to its outstanding performance and integration advantages, profoundly impacting braking safety, energy efficiency, and the level of vehicle intelligence.
System Definition and Core Characteristics
The One-box brake-by-wire system is a mainstream technological solution within Electro-Hydraulic Braking systems. Its core innovation lies in the high-level integration of the traditional braking system's electronic booster and vehicle stability control system into a single, compact physical unit, achieving significant structural simplification.
The most notable feature of this system is the achievement of complete decoupling between the brake pedal and the actuator. In traditional braking systems, the driver's pedal force acts directly on the brake wheel cylinders through mechanical or hydraulic connections. In the One-box system, depressing the brake pedal primarily generates an electrical signal. This signal, along with information such as wheel speed and vehicle attitude, is transmitted to the Electronic Control Unit (ECU). The ECU calculates the precise braking force required and commands a motor to drive the hydraulic mechanism to execute the braking. This model of "signal transmission" replacing "force transmission" forms the foundation for the intelligent control of brake-by-wire systems.
System Composition and Working Principle
A complete One-box system operates through the synergistic work of three main modules: perception, decision-making, and execution.
The Perception Module is responsible for collecting various critical signals. This includes displacement sensors monitoring brake pedal travel, wheel speed sensors measuring the rotational speed of all four wheels, and an Inertial Measurement Unit used to detect lateral/longitudinal acceleration and yaw rate of the vehicle body. These sensors collectively form the system's "neural network" for perceiving vehicle dynamics and driver intent.
The core of the Decision-Making Module is a high-performance Electronic Control Unit. Acting as the "brain," the ECU processes all sensor data in real-time and runs complex control algorithms. It must not only handle the driver's basic braking requests but also deeply integrates advanced functions such as Anti-lock Braking and Electronic Stability Control. It can coordinate torque between the braking and drivetrain systems within milliseconds to achieve optimal control.
The Execution Module serves as the system's "hands and feet." Its core is a highly integrated electro-mechanical-hydraulic unit. This typically includes a motor responsible for providing power, a transmission mechanism converting rotational motion into linear motion, a hydraulic master cylinder for pressure generation, and a solenoid valve group for precise control of fluid flow. During normal operation, the motor rapidly pushes the master cylinder piston according to ECU commands to establish precise braking hydraulic pressure. To ensure absolute safety redundancy, the system also incorporates an independent mechanical backup mechanism. Upon detecting a complete failure of the electronic control system, backup valves immediately switch to restore the traditional hydraulic connection between the pedal and the wheel cylinders, safeguarding the most basic human-powered braking capability.
Key Technical Advantages and Application Value
The integrated and electronically controlled design of the One-box system provides it with significant multidimensional advantages, precisely meeting the developmental needs of modern automobiles.
In terms of improving energy efficiency and range, the system performs outstandingly. Benefiting from the pedal decoupling design, it can achieve millisecond-level precise synergy with the electric drivetrain, seamlessly and efficiently distributing electric motor braking force and hydraulic braking force. This means that in most braking scenarios, the energy recovery system can operate at maximum efficiency, converting kinetic energy into electrical energy, directly and positively contributing to extending the range of electric vehicles.
Regarding enhanced performance and safety, its electronically controlled actuator responds far faster than traditional vacuum boosters, enabling shorter braking distances and more stable vehicle dynamics. The integrated design also allows for more refined and efficient control of functions like ABS and ESC, effectively enhancing the vehicle's handling stability limits, especially under extreme conditions such as low-adhesion road surfaces or emergency avoidance maneuvers.
In empowering intelligent driving and optimizing user experience, the One-box system provides indispensable support. It serves as a reliable and precise execution terminal for advanced driver-assistance functions like Adaptive Cruise Control and Automatic Emergency Braking. Furthermore, software-adjustable brake pedal feel allows automakers to customize differentiated driving experiences according to different vehicle positioning, even enabling seamless "comfort stop" functions, significantly improving the quality of the ride and drive.
Technical Challenges and Manufacturing Requirements
Despite its clear advantages, the One-box system, as a precision electro-mechanical-hydraulic integrated product, faces high barriers in its development and manufacturing. The system internally involves precision mechanical machining, hydraulic sealing, motor control, and complex software algorithms, making technological integration highly challenging. Simultaneously, as a core component related to driving safety, its functional safety level requirement reaches the highest ASIL-D rating, imposing extreme demands on component reliability, system redundancy design, and testing validation.
Precisely because of this, the consistency and reliability of its mass production are highly dependent on high-standard automated and intelligent manufacturing lines. From the precision machining and cleaning of core metal components like valve bodies and pistons, to the micron-level precision press-fitting of sensors and solenoid valves, and further to fully automated functional testing and sealing inspection after assembly, every step requires guaranteed processes and equipment.
Conclusion
Through a high degree of integration and comprehensive electrification, the One-box brake-by-wire system represents a clear direction for the current development of braking technology. It is not only a platform for enhancing vehicle braking performance but also a cornerstone for achieving efficient energy recovery and empowering advanced intelligent driving, playing a key role in the automotive industry's transformation.
HOLS Automation, with its deep roots in industrial automation, keenly understands the stringent requirements that next-generation automotive core technologies like brake-by-wire chassis place on manufacturing processes. Leveraging our strong technical team and non-standard customization capabilities, we focus on providing high-performance, high-reliability intelligent manufacturing solutions for the automotive components industry. For the One-box brake-by-wire system, we can deliver full-process production lines covering automated assembly, precision press-fitting, intelligent inspection, and closed-loop functional testing. With micron-level process control, full-process data traceability, and stable, efficient delivery capabilities, we assist customers in achieving high-quality, scaled production, jointly advancing the rapid implementation and industrial upgrade of smart mobility technology.
