Vehicle Zonal Controller Clock Sync Using UWB Time-of-Flight

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Solution Overview

Problem

In vehicles with zonal controller architectures, ensuring accurate real-time communication between zonal controllers is challenging due to the need for synchronization of internal clocks, which is crucial for reliable and safe vehicle operations.

Innovation Solution

A synchronization method using ultra wideband (UWB) radios to transmit and capture synchronization packets, determining time stamps and time-of-flight values to adjust internal clocks of zonal controllers to synchronize them with a master clock, ensuring accurate time synchronization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If internal clocks of multiple zonal controllers are used for distributed control, then device complexity and wire cost are reduced, but clock synchronization accuracy deteriorates

Engineering Contradiction:

Improvecontrol architecture complexityVSAvoidclock synchronization accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent introduces UWB radios as an intermediary mechanism between zonal controllers to enable precise time-of-flight measurements. The UWB radio transmits synchronization packets with timestamps, allowing controllers to calculate propagation delays and adjust their internal clocks accordingly, thus maintaining synchronization accuracy in a distributed architecture

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces traditional mechanical/electrical clock synchronization methods with electromagnetic-based UWB time-of-flight measurement. By using radio wave propagation time measurements instead of physical connection-based synchronization, the system achieves higher precision while maintaining the benefits of distributed architecture

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If UWB synchronization packets are transmitted between controllers, then clock synchronization accuracy is improved, but use of energy and communication overhead increase

Engineering Contradiction:

Improveclock synchronization accuracyVSAvoidenergy consumption for synchronization

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic transmission of synchronization packets at controlled intervals rather than continuous transmission. This allows the system to maintain clock synchronization accuracy while reducing energy consumption by keeping UWB radios in low-power states between synchronization events

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The synchronization mechanism is designed to be self-regulating, where each zonal controller independently measures time-of-flight, calculates its own clock offset, and adjusts its internal clock without requiring continuous external intervention. This reduces overall system energy consumption while maintaining synchronization

Inventive Principle:

Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables precise synchronization of zonal controllers, enhancing the reliability and safety of vehicle operations by ensuring seamless and instantaneous communication between zonal controllers and master controllers.

Implementation Method 1

for each corresponding synchronization packet in a sequence of one or more synchronization packets transmitted by a transmitting ultra wide band (UWB) radio

Methodology Applied

Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

obtaining a reference time-of-flight (ToF) value, and based on the respective reference timestamp for each corresponding synchronization packet, the respective received time stamp for each corresponding synchronization packet, and the reference ToF value

Methodology Applied

Scientific EffectTime-of-flight measurement: Time of Flight

Data Source

PatentUS12531593B2Synchronization of zonal controllers using ultra wideband radios

Publication Date: 2026.01.20 KARMA AUTOMOTIVE LLC

AI summary

A method includes receiving a corresponding synchronization packet captured by a receiving UWB radio associated with a zonal controller of a vehicle. The synchronization packet includes a respective reference timestamp that includes a time of a master clock when a transmitting UWB radio transmitted the corresponding synchronization packet. The method also includes determining a respective received time stamp for the corresponding synchronization packet and obtaining a reference ToF value. The received time stamp includes a time of an internal clock of the zonal controller when the corresponding synchronization packet was captured by the receiving UWB radio. Based on the respective reference timestamp, the respective received time stamp, and the reference ToF value, the method also includes determining the internal clock of the zonal controller is not synchronized with the master clock and adjusting the internal clock to synchronize the internal clock of the zonal controller with the master clock.