Dielectric Waveguide Rotary Joint for Low-Loss Sensor Communication

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Autonomous vehicles face challenges in reliably communicating data between rotating sensors and vehicle components without physical connections, leading to signal interference and inefficiencies in existing communication systems.

Innovation Solution

A communication system utilizing a dielectric waveguide cable and rotary joint enables two-way electromagnetic signal transmission between rotating sensors and vehicle-side units, minimizing signal loss and interference by aligning the waveguide's axis with the rotation axis and reducing the need for electrical-to-RF conversions near the rotary joint.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If wireless contactless rotary joint is used for signal transmission between rotating sensors and vehicle components, then signal interference is reduced, but signal loss increases

Engineering Contradiction:

Improveelectromagnetic interferenceVSAvoidsignal loss

Core Design Contradiction:

Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

A dielectric waveguide cable is introduced as an intermediary component between the rotary joint and the vehicle-side communication unit. The waveguide cable transmits electromagnetic signals from the rotary joint to the communication unit, reducing signal loss while maintaining the electromagnetic isolation benefits of the contactless rotary joint. This mediator allows efficient signal transmission over the connection distance without requiring direct electrical contact.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Loss of energy

If dielectric waveguide cable is used to transmit electromagnetic signals, then signal loss is reduced, but device complexity increases

Engineering Contradiction:

Improvesignal lossVSAvoidsystem complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The dielectric waveguide cable serves multiple functions: it transmits electromagnetic signals efficiently, provides electromagnetic shielding, and maintains a compact connection between components. By combining these functions into a single component, the system achieves reduced signal loss without proportionally increasing complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses specific parameter optimizations including the dielectric constant of the waveguide material, the impedance matching of the cable, and the alignment of the waveguide axis with the rotation axis. These parameter changes enable efficient signal transmission while keeping the overall system design manageable.

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If electrical-to-RF conversions are performed near the rotary joint, then communication flexibility is improved, but electromagnetic interference increases

Engineering Contradiction:

Improvecommunication flexibilityVSAvoidelectromagnetic interference

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The electrical-to-RF conversion functionality is extracted from the rotary joint area and relocated to the vehicle-side communication unit. This separation removes the source of electromagnetic interference from the sensitive rotary joint region, allowing electrical conversions to occur at a distance where they do not interfere with the contactless signal transmission.

Inventive Principle:

Principle #2Taking out (Extraction)

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

This solution provides reliable, high-speed data transmission with reduced electromagnetic interference, improving communication efficiency and electromagnetic compatibility, and eliminating the need for serializer/deserializer hardware and driver/receiver circuits.

Implementation Method 1

A proximal end of the dielectric waveguide cable can be coupled to the second antenna and a distal end of the dielectric waveguide cable can be affixed to the second communication unit at a location bordering a space defined by the rotary joint. First electromagnetic signals transmitted from the first antenna to the second antenna can enter the distal end of the dielectric waveguide cable following propagation of the first electromagnetic signals across the rotary joint.

Methodology Applied

Scientific EffectElectromagnetic waveguide: Waveguide

Implementation Method 2

The second communication unit can also comprise a dielectric waveguide cable extending from the second antenna to the rotary joint

Methodology Applied

Scientific EffectDielectric: Dielectric

Data Source

PatentUS11804896B2Automotive communication system with dielectric waveguide cable and wireless contactless rotary joint

Publication Date: 2023.10.31 WAYMO LLC

AI summary

A communication system is disclosed. The system can include a first communication unit including a first antenna, a second communication unit including a second antenna and a dielectric waveguide cable, and a rotary joint configured to enable the first unit to rotate with respect to the second unit about an axis of rotation of the system. The dielectric waveguide cable can extend from the second antenna to the rotary joint, where a proximal end of the cable can be coupled to the second antenna and a distal end of the cable can be affixed to the second unit at a location bordering a space defined by the rotary joint. The first and second units can be configured to engage in two-way communication with each other. An axis of the distal end of the cable can be substantially aligned with the axis of rotation of the system.