ZoZo Auto Research has released the "2026 Smart Vehicle Zone Controller Research Report".
Currently, the mainstream mass-produced Zonal architecture is dominated by the quasi-central + zonal architecture, adopting a hardware solution with multiple central computing platforms and 2 to 4 zone controllers. The zone controllers at this stage are referred to as body-type ZCUs, which are still primarily focused on implementing body-related functions. Functions related to the powertrain domain and chassis domain have not been split and still exist as independent functional domain controllers.
Two Main EE Architecture Paths for the Next Stage
Given the varying integration levels of central computing platforms, two main EE architecture paths will emerge in the next stage:
Path 1 — Cross-Domain Fusion Zonal Architecture: The integration level of the cockpit-driving integrated computer is further enhanced, forming a cross-domain fusion Zonal architecture. In this architecture, body, powertrain, and chassis-related functions are entirely decomposed and distributed, then fused into nearby ZCUs. The zone controllers at this stage are primarily cross-domain fusion ZCUs, which will be mainly deployed in high-end L3+ routes in the future. They feature lightweight edge preprocessing capabilities and require high-performance multi-core MCUs, providing high computing power, large memory capacity, strong communication capabilities, and virtualization support;
Path 2 — Highly Integrated Central Computing Zonal Architecture: Central computing is further integrated, and the architecture is continuously streamlined. The ZCU thoroughly weakens local computing power, developing towards a central brain + intelligent control cerebellum + I/O zone control direction, further reducing costs and improving integration. The zone controllers at this stage are positioned as pure edge I/O nodes. I/O-type ZCUs no longer run application logic, retaining only power distribution, protocol forwarding, and driving functions. Differentiation decreases, with lower requirements for MCU computing power and memory, focusing instead on the richness of I/O interfaces.
Comparison of Characteristics Among Three Types of ZCUs
Source: ZoZo Auto Research "2026 Smart Vehicle Zone Controller Research Report"
Cross-Domain Fusion ZCU: Vehicle Control Strategies for the Motion Domain Shift Up to HPC, While I/O Execution Shifts Down to ZCU
Advanced autonomous driving functions require the autonomous driving domain to simultaneously invoke torque, braking, steering, and suspension vertical control, imposing high demands on the coordinated control of the powertrain and chassis, and requiring extremely low deterministic latency. Traditional motion domain control solutions are generally controlled separately by the powertrain domain controller and the chassis domain controller, which are responsible for vehicle control algorithms, processing massive I/O acquisition, driving solenoid valves, power distribution, and gateway forwarding. The autonomous driving domain needs to connect across domains with two domain controllers, resulting in multiple links, increased communication latency, and complex interfaces, which is detrimental to hardware-software decoupling and vehicle control function updates. Therefore, in advanced autonomous driving vehicles at L3 and above, the integration of the powertrain and chassis domains is highly necessary.
Integrating the powertrain and chassis domains into the zone controller essentially splits the two major responsibilities of the domain controller: shifting strategies up and sinking I/O execution down. The cross-domain fusion ZCU does not cram all the vehicle's powertrain and chassis into the ZCU; instead, it sinks the real-time I/O, local execution, sub-closed-loop, power distribution, and gateway capabilities of the powertrain and chassis domains into nearby ZCUs. Sub-functions such as EPS, EPB, and CDC are migrated to the ZCU software stack, eliminating independent chassis ECUs, while VMC vehicle control logic is shifted up to the central HPC.
Actuators in the powertrain and chassis domains are actually highly suitable for integration into ZCUs. Motion domain-related sensors and actuators, such as wheel speed sensors, brake motors, and steering motors, are mainly concentrated near the wheels and chassis, making the physical distance to the ZCU the shortest. Connecting motion domain actuators to nearby ZCUs ensures the high real-time performance required by advanced autonomous driving functions through extremely short communication links.
Therefore, cross-domain fusion ZCUs impose high requirements on the main control MCU in terms of processing capability, peripheral interfaces, virtualization mechanisms, and functional safety.
New Requirements for Main Control MCUs in Cross-Domain Fusion ZCUs
Source: ZoZo Auto Research "2026 Smart Vehicle Zone Controller Research Report"
Currently, the cross-domain fusion ZCU integrating the motion domain has become the mainstream promoted solution for the next-stage EE architecture. Most domestic mainstream OEMs have planned solutions for the next-generation zone controller to integrate powertrain and chassis domain functions, and major Tier 1 suppliers have also launched system solutions for cross-domain fusion ZCUs.
Taking the rear zone controller Re-ZCU by Hirain as an example: In 2026, Hirain showcased the rear zone controller Re-ZCU at the Beijing Auto Show. This is a "chassis + body" fusion zone controller using a single control chip (MCU). While retaining chassis control functions such as single-channel electronic parking brake (EPB), dual-chamber air springs, and dual-valve continuously damping control (CDC), it also integrates common body control functions, such as rear tailgate switch, rear seat adjustment, rear air conditioning adjustment, and rear lighting adjustment.
The Re-ZCU integrates the chassis and some body functions in the rear cabin area, breaking the functional boundaries of traditional independent ECUs. This design eliminates the need for independent chassis domain controllers and body controllers in the rear cabin area, helping to simplify the vehicle's circuit layout and reduce vehicle weight and cost.
ZCU Supports Distributed Audio Architecture, Transmitting Audio Streams Based on AVB+TSN Ethernet
In addition to integrating the motion domain, the next-stage zone controllers will also integrate audio amplifiers to achieve independent audio zone management. Traditional audio solutions centrally deploy amplifier modules in a separate amplifier ECU or cockpit domain controller. All speaker and microphone signals are converged into the independent amplifier or cockpit domain controller for DAC, amplification, and sound effect processing. Using an A2B dedicated audio bus for daisy-chain cross-zone wiring leads to issues such as excessively long wire harnesses, complex wiring, and signal loss.
Given the evolution of the Zonal architecture and the increasing user demands for cockpit audio experiences, the distributed audio architecture disperses amplifier functions into ZCUs, eliminates independent amplifier ECUs, and connects speakers to nearby ZCUs, which has become a direction jointly explored by the industry. In the distributed audio architecture, the power amplification circuit is built into the zone controller ZCU. The cockpit SoC is responsible for audio algorithm decoding, and AVB+TSN Ethernet transmits digital audio to ZCUs in each zone to drive speakers nearby, achieving flexible management, synchronized transmission, and personalized experiences for multi-zone audio.
Hardware Integration: The zone controller integrates multi-channel audio codecs, AVB/TSN Ethernet audio bridging, local storage (for preloading sound effect algorithms), and DSP amplifiers. It directly collects and processes audio node signals such as microphones, speakers, and amplifiers in its own zone, and transmits them to the central domain controller via the backbone network for interaction;
Software Decoupling: Through the SOA (Service-Oriented Architecture), audio functions are abstracted into independent services (such as "volume adjustment service" and "sound effect mode service"). Each zone controller calls them on demand, while the central domain controller is only responsible for strategy orchestration.
Wire Harness Simplification: The zone controller connects audio nodes in its zone through local power supply and audio buses, effectively shortening the length of speaker wire harnesses and significantly reducing the weight and wiring complexity of in-vehicle wire harnesses. While ensuring system functions, it reduces hardware BOM costs, lowering vehicle manufacturing costs and weight. At the same time, it better realizes software-defined audio, enabling flexible platform-based iterations for different vehicle models.
Taking Infineon's AVB distributed audio solution based on zone controllers as an example: Through the design of "central computing + distributed zone controllers," combined with the high bandwidth and low latency characteristics of Ethernet and in-vehicle zonal audio requirements, it achieves flexible management, synchronized transmission, and personalized experiences for multi-zone audio.
Central Computing Unit and Ethernet Switch: Undertakes audio data processing, network management, and traffic scheduling functions. It connects various zonal audio controllers via Ethernet to build the "backbone network" for in-vehicle audio and video transmission. Meanwhile, based on the time synchronization (gPTP) and Quality of Service (QoS) mechanisms of the AVB protocol, it ensures low-latency, stutter-free synchronized transmission of multi-zone audio streams;
Distributed Zone Controllers:
Zonal Audio Functions: Each physical zone controller receives AVTP audio data via Ethernet and independently manages audio output to achieve zoned personalized audio experiences.
Audio Codec: It is the "local processing center" for zonal audio, responsible for encoding (analog to digital), decoding (digital to analog), mixing, and amplifying audio signals. Among them, I2S is an automotive-grade serial audio bus suitable for short-distance, high-reliability audio transmission; TDM supports multi-channel audio transmission on the same link, improving bandwidth utilization.
Main Control MCU: It adopts Infineon's AURIX™ TC4x. This chip features dedicated hardware peripheral support designed for AVB, supporting AVB protocols such as IEEE 802.1AS and IEEE 802.1Qav, while also supporting TSN protocols such as IEEE 802.1Qbu, IEEE 802.1Qbv, and IEEE 802.1CB.
Cross-Domain Fusion ZCU Restructures Business Models: Hardware Standardization and OEM-Led Software Differentiation
In the SDV (Software-Defined Vehicle) era, automotive EE architectures achieve rapid reuse across vehicle models and segments through modular design and software configuration. The zone controller is the core carrier of this "standardized hardware + software differentiation" model.
The cross-domain fusion ZCU is no longer a simple body I/O + power distribution + gateway, but a local edge computing unit integrating multiple functions such as body, gateway, power distribution, partial chassis/powertrain execution, and audio amplifiers. It needs to simultaneously support ASIL-B and ASIL-D, relying on Hypervisor virtualization for safety isolation. Therefore, the traditional Tier 1 black-box model will gradually decrease, and the new model will move towards in-depth joint research by multiple parties, layered collaboration with hardware-software decoupling, platform-based pre-research, and OEMs mastering upper-level SOA and whole-vehicle architecture definition.
Currently, all parties in the zone controller industry chain are exploring more flexible cooperation models. Chip manufacturers are extending upwards to underlying software and reference platforms, the status of basic software manufacturers is rising, OEMs are moving upwards to master whole-vehicle architecture/SOA/application layers, and Tier 1 or EMS manufacturers are taking on more system integration and hardware implementation. For example, Infineon, Flex, and Vector jointly released a flexible zone controller development kit; ST and AutoCore jointly released an Ethernet-based ZCU distributed audio solution; and UAES launched a "building block" platform solution, supporting OEMs in flexibly choosing different supply levels from hardware to complete solutions.
Taking the tripartite joint flexible ZCU development kit by Infineon, Vector, and Flex as an example: At CES 2026, Flex, together with Infineon and Vector, jointly released a flexible zone controller development kit. The core of this solution lies in modular design and scalable architecture. It internally consists of about 30 building blocks. Developers can flexibly combine and configure them according to different vehicle models and functional requirements, providing a clear path for subsequent mass production and quickly adapting to various vehicle model needs ranging from entry-level to luxury, and from traditional ICE to advanced autonomous driving. This solution adopts a one-stop turnkey model of "chip manufacturer + software manufacturer + EMS manufacturer". Infineon provides core semiconductor solutions from MCUs and power semiconductors to security chips, Vector provides high-performance embedded software and development tools, and Flex is responsible for the hardware design, manufacturing, and mass production of the ZCU.
The highest configuration version of this development kit adopts a dual-MCU redundant architecture to achieve fail-safe operation. It uses Infineon's TC4x series main control MCU, with real-time performance reaching 2 × 6,810 DMIPS, equipped with 2 × 10MB memory and 2 × 21MB non-volatile memory, leaving sufficient margin for L4 autonomous driving and high-safety-level applications. This design ensures functional safety and provides a solid hardware foundation for realizing "software-defined vehicles". Automakers can continuously unlock new functions or optimize existing performance through software updates and configurations on standardized hardware, greatly shortening the R&D cycle for new vehicle models.
A single-MCU version is also available. Developers can flexibly choose based on actual project requirements and cost considerations, fully reflecting its core concept of "scalable and reusable".
In terms of communication interfaces, this zone controller solution covers almost all mainstream protocols of current in-vehicle networks. Ethernet interfaces include two 1000BASE-T1 (one of which can be upgraded to 2500BASE-T1), two 100BASE-T1, and two 10BASE-T1S interfaces. For CAN, it provides two 5Mbit/s CAN-FD interfaces supporting "partial networking", along with 18 5Mbit/s CAN-FD interfaces not supporting partial networking for conventional body and chassis communication. In addition, it integrates 16 LIN interfaces, one 10Mbit/s FlexRay interface, two 125kbit/s bidirectional PSI5 interfaces, four DSI3 interfaces (capable of connecting up to 12 ultrasonic sensors), two SENT interfaces (upgradeable to SPC protocol with master trigger), and four WSS three-wire wheel speed sensor interfaces (upgradeable to a two-wire solution).
At the signal and power control level, the zone controller provides 4 pull-down digital inputs, 10 pull-up digital inputs, 24 pull-up analog inputs, and 2 5V analog output interfaces, which can directly interface with various in-vehicle sensors and actuators.
The power control section includes 8 electronic fuses with hardware i²t protection, 42 high-side switches, 4 low-side switches, 8 motor half-bridges, and 1 brushed motor full-bridge. It can support power supply for up to 63 ECUs or actuators, with a continuous current switching capability of 85A and a total distributed current of up to 688A.
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