Embedded Switch Tiered Communication for Motor Drive Control Data

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Solution Overview

Problem

In motor drive applications, the increasing complexity and resource burden on motor controllers due to additional sensors and diverse communication protocols lead to inefficiencies in communication, particularly in handling real-time control data and health monitoring data, which complicates network communication and demands more from the motor controller's resources.

Innovation Solution

An embedded network switching device with a three-tier communication protocol is introduced, where the first tier ensures deterministic data delivery for motor control, the second tier allows for high-rate but non-deterministic data transmission, and the third tier handles slow-changing data, prioritizing and managing data transmission based on its criticality and bandwidth requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If additional sensors and diverse communication protocols are integrated into motor controllers, then measurement precision and adaptability are improved, but device complexity and resource burden increase

Engineering Contradiction:
Improvesensor monitoring capabilityVSAvoidcontroller resource burden
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the communication system into three distinct tiers based on data criticality and bandwidth requirements. Tier 1 handles deterministic real-time control data, Tier 2 handles high-rate non-deterministic data, and Tier 3 handles slow-changing health monitoring data. This segmentation allows the motor controller to process different types of sensor data through appropriate communication channels, reducing resource burden while maintaining measurement precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an embedded network switching device as an intermediary between the motor controller and various sensors/devices. This switch handles protocol conversion and data routing, offloading communication processing from the motor controller. The switch manages multiple communication protocols simultaneously, allowing the controller to focus on control functions while the intermediary handles communication complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If all devices are connected directly to the industrial network with network interfaces, then communication reliability is improved, but device complexity and cost increase

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidnetwork interface requirement
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The embedded network switching device serves multiple functions: it acts as a protocol converter, a data router, and a gateway for devices without network interfaces. By consolidating these functions into a single multi-functional device, the system achieves reliable communication for all devices without requiring each device to have its own network interface, thus reducing overall device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The network switch acts as an intermediary that enables indirect communication between devices. Instead of requiring direct network connections between all devices, the switch mediates communication by receiving data from one device and forwarding it to the appropriate destination. This approach maintains communication reliability while allowing devices to connect through the intermediary rather than requiring direct point-to-point connections.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If real-time control data is transmitted with deterministic delivery guarantees, then control precision is improved, but communication bandwidth consumption increases

Engineering Contradiction:
Improvecontrol precisionVSAvoidcommunication bandwidth
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The communication bandwidth is segmented into three tiers with different allocation strategies. Tier 1 is dedicated to deterministic real-time control data with guaranteed bandwidth allocation, ensuring control precision. Tier 2 and Tier 3 handle non-critical data with best-effort service. This segmentation ensures that critical control data receives the necessary bandwidth guarantees without consuming excessive overall bandwidth, as non-critical data shares the remaining capacity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different quality of service levels are applied locally to different data types based on their requirements. Real-time control data in Tier 1 receives deterministic delivery guarantees with strict timing constraints, while health monitoring data in Tier 3 accepts variable timing. This local quality differentiation optimizes bandwidth usage by applying high reliability only where necessary for control precision, rather than uniformly across all communications.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3471353B1Method and apparatus for communication in a motor drive application
Publication Date: 2021.07.28 ROCKWELL AUTOMATION TECH INC
  • EP3471353B1 patent drawingFigure 1
  • EP3471353B1 patent drawingFigure 2
  • EP3471353B1 patent drawingFigure 3~4

AI summary

The subject matter disclosed herein describes a switch embedded in a motor controller and a network protocol executing on the switch to provide communication between devices connected to the motor controller in a motor drive application. The embedded switch is configured to communicate via separate ports with an external controller, a network interface for the motor controller, additional motor controllers, and with the motor or other devices mounted on the motor. The network protocol includes a first tier for data that requires deterministic delivery at a high data rate, a second tier for data that requires a high delivery rate but is also tolerant of some variation in delivery time, and a third tier for data that may be delivered at a slower data rate. The embedded switch receives data at any port, identifies the communication tier to which the data belongs, and delivers it to another port accordingly.