How We Optimised a Software-Defined Steer-by-Wire System for an Autonomous-Ready E-Buggy Platform

The objective was to develop a cost-effective drive-by-steering system that reduces mechanical complexity while maintaining precise steering response and compliance with functional safety standards. Existing mechanical steering architectures relied heavily on physical linkages, limiting software control flexibility, complicating ASIL D compliance, and making the transition toward modern SDV architectures challenging. The program aimed to simplify the steering system through a software-centric approach, reduce development and validation effort, improve software reusability, and accelerate time-to-market for future autonomous-ready vehicle platforms.

Primary Objectives

• Develop a software-defined electromechanical steering architecture with reduced dependency on mechanical linkages.
• Achieve precise steering response using closed-loop control with high-resolution sensor feedback.
• Enable dual-mode steering supporting both manual input and digital commands for autonomous functions.
• Implement an ASIL D–ready safety architecture with redundancy and no single points of failure.
• Support SDV principles and Level 3+ autonomous readiness.
• Reduce development, manufacturing, and validation costs through simplified system design.
• Accelerate time-to-market through scalable, reusable software components.

Our automotive engineering team designed and implemented a Steer-by-Wire system with a software-defined electromechanical architecture. The solution enables precise digital steering control while significantly reducing mechanical dependency and system complexity.

The steering platform was designed to support both manual steering and digital steering commands, enabling seamless transition between conventional driving and autonomous operation. By adopting a software-driven control strategy, we enabled faster validation cycles, simplified assembly, and future scalability without hardware redesign.

The system delivers a lightweight, energy-efficient, and ASIL D–ready steering platform that aligns with Software-Defined Vehicle architectures and provides a robust foundation for Level 3+ autonomous capabilities.

Key Highlights

RTOS-Driven Real-Time Steering Control

• We implemented an RTOS-based architecture on the NXP Semiconductors S32K series microcontroller to ensure deterministic real-time performance. Critical motor control tasks were isolated from non-critical functions, ensuring predictable and stable steering response even under high processing loads.

High-Precision Closed-Loop Feedback System

• We designed a closed-loop control strategy using high-resolution Hall-effect sensors to continuously monitor steering position. Real-time feedback is compared against target angles, allowing instant correction of deviations and eliminating mechanical play and drift.

PID-Based Steering Control Algorithm

• We implemented a robust PID (Proportional-Integral-Derivative) control algorithm to regulate steering dynamics. The controller continuously calculates angular error and dynamically adjusts motor output using software PWM, ensuring smooth convergence, accurate alignment, and oscillation-free steering behaviour.

CAN-Based ECU Communication

• We used Controller Area Network (CAN) as the primary communication backbone between sensor and actuator ECUs. This approach replaced complex point-to-point wiring with a reliable serial bus, enabling synchronized real-time data exchange and improved system robustness.

Dual-Mode Steer-by-Wire Operation

• We enabled dual-mode steering capability, allowing the vehicle to receive digital steering commands for autonomous operation while retaining immediate manual override through the steering wheel.

ASIL D–Ready Safety Architecture

• We implemented a safety architecture with redundant sensors, actuators, and control paths to eliminate single points of failure. This design supports ASIL D compliance and provides confidence for safety-critical and autonomous driving applications.

SDV-Ready and Cost-Optimized Design

• We delivered a lightweight, software-defined steering platform that supports future feature expansion, simplified manufacturing, plug-and-play assembly, and reduced development, manufacturing, and validation costs.

• Improved handling and vehicle stability through precise, software-controlled steering
• Reduced energy consumption via on-demand electric actuation
• Robust foundation for Level 3+ autonomous driving and complex maneuver execution
• Improved cost efficiency across development, manufacturing, and validation phases
• Faster time-to-market enabled by scalable and reusable software architecture
• SDV-ready steering platform aligned with future autonomous mobility strategies