The Digital Body — Drive-by-Wire & Vehicle Control in Autonomous Systems

If perception is how autonomous vehicles see, then control is how they move. And in a world without a human driver behind the wheel, traditional mechanical systems no longer suffice. Steering wheels, pedals, and hydraulic linkages must give way to software-controlled systems that can react faster, more precisely – and above all, more safely.

Welcome to the era of Drive-by-Wire.

In this blog, we explore how electronic vehicle control systems are shaping the body of autonomous machines. We explain what Drive-by-Wire means, why it’s essential, and how it is transforming mobility in sectors far beyond passenger cars.

What Is Drive-by-Wire?

Drive-by-Wire (DbW) refers to the replacement of mechanical or hydraulic control systems with electronic actuators and digital signals. That includes:

• Steer-by-Wire: Steering commands transmitted via electric signals
• Brake-by-Wire: Electronic braking with no physical connection to pedals
• Throttle-by-Wire: Digital acceleration control
• Shift-by-Wire: Gear changes handled electronically

These systems are not just replacements – they’re upgrades. They offer:

• Higher precision
• Reduced weight
• Fewer mechanical failure points
• Freedom in vehicle design (no steering column required)

And most importantly, they provide the platform to implement redundancy and fail-operational architectures, which are required by modern safety regulations (e.g., ISO 26262 ASIL D, UNECE R79).

Redundancy and Fail-Operational Design: No Option, But a Must

Autonomous vehicles cannot rely on a single point of control. If the steering or braking system fails—even for a split second – lives are at risk. That’s why fail-operational architectures are essential.

Arnold NextG’s NX NextMotion system, for example, features:

• Dual redundant ECUs with ASIL-D certification
• Multiple sensor validation (e.g., 2oo3 architecture)
• Independent communication paths (SAFE_CAN and Automotive Ethernet)
• Backup energy supply for critical subsystems

“You don’t build Level 4 without building like aerospace. Redundancy is not an afterthought – it’s the system.”
– Mathias Koch, Arnold NextG

This kind of architecture allows the vehicle to continue operating safely even if one system fails – a core requirement for Levels 3 to 5 autonomy.

Why Mechanical Systems No Longer Cut It

In traditional vehicles, a driver can compensate for system faults: press harder on the brakes, steer around obstacles, or shift to neutral. But in autonomous operation – especially in driverless use cases – this isn’t possible.

Imagine:

• A logistics vehicle navigating an industrial yard
• A mining hauler in a remote, harsh environment
• A military convoy under teleoperated control
• A shuttle bus in a low-speed urban environment

All of these require systems that respond to digital commands, self-monitor, and isolate faults without human intervention. Mechanical linkages simply don’t offer the speed, intelligence, or modularity required.

Control Systems as Part of a Larger Architecture

Drive-by-Wire doesn't operate in isolation – it’s integrated into the entire vehicle’s control stack:

• Input: From the AD stack (planning & decision-making)
• Execution: Via electronic actuators (steering, braking, throttle)
• Monitoring: Through real-time diagnostics, feedback loops, and watchdog systems

That’s why leading AD stack providers – from military OEMs to logistics platform vendors – are actively seeking Drive-by-Wire platforms that are modular, certifiable, and scalable.

Enabling New Vehicle Architectures & Platforms

Without the constraints of a steering column or mechanical linkages, Drive-by-Wire also enables:

• Reconfigurable cabins (e.g., shuttles without a driver seat)
• Smaller vehicle footprints for last-mile delivery
• Fully remote operation with zero local controls
• Low-floor accessibility for urban transport

This unlocks new business models in mobility-as-a-service, defense logistics, automated agriculture, and intralogistics – each with unique layout, control, and safety needs.

Conclusion: Control Without Compromise

Autonomous systems demand more than vision – they demand flawless execution. That’s where Drive-by-Wire becomes the indispensable nervous system of mobility. It ensures that decisions made by AI are translated into safe, predictable motion – under any condition, at any moment.

In the next part of our series, we’ll look at the “brains” of the vehicle: the planning & decision-making software that makes autonomy possible.

References

• UNECE R79, ISO 26262 (ASIL-D), UNECE R155 Cybersecurity
• Arnold NextG, NX NextMotion Safety White Paper, 2025
• Arnold NextG, Fail-Operational Architecture Analysis, 2025
• BMDV (2024), Handbuch Autonomes Fahren – Öffentlicher Verkehr
• FMVSS / ISO/ECE Comparison Study, 2024