IoT Control Delay Updating for Network Jitter Compensation

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Solution Overview

Problem

Existing control systems for IoT terminals do not effectively account for communication apparatuses in network delays, leading to inaccuracies in delay information estimation and increased jitter effects, which hinder real-time control performance.

Innovation Solution

A control system that includes a control unit and communication processing units measuring and sequentially updating processing times to provide accurate delay information for incorporation into control algorithms, actively addressing network delay and jitter impacts by measuring and transmitting processing times from multiple communication apparatuses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If RTT measurement is used to estimate delay information, then delay information can be obtained, but the accuracy deteriorates when network delay increases beyond control period

Engineering Contradiction:

Improvedelay information accuracyVSAvoidcontrol period

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent segments the network delay measurement into multiple components by measuring processing times at different communication apparatuses (sensor node, communication apparatus, control apparatus) separately. This segmentation allows accurate delay information to be obtained even when total network delay exceeds control period, as each segment's processing time is measured independently rather than relying on RTT measurement that fails when delay > control period/2

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces communication apparatus as an intermediary that measures and reports its processing time to the control apparatus. This intermediary measurement approach enables accurate delay information collection without requiring RTT measurement between endpoint devices, solving the accuracy deterioration problem when network delay increases

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If communication apparatus processing time increases, then network delay magnitude increases, but RTT measurement becomes unreliable

Engineering Contradiction:

ImproveRTT measurement reliabilityVSAvoidnetwork delay

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent implements feedback mechanisms where communication apparatus measures its own processing time and feeds this information back to the control apparatus. This feedback approach maintains measurement reliability even when processing time increases, as each apparatus monitors its own performance rather than relying on RTT measurements that become unreliable when delay increases

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

Communication apparatus performs self-measurement of its processing time without requiring external RTT measurement. This self-service approach ensures reliable delay information is obtained regardless of network delay magnitude, as each apparatus independently monitors its own processing performance

Inventive Principle:

Principle #25Self-service

3Productivity

If delay information is estimated based on previous RTT values, then control can continue, but deviation from actual delay occurs

Engineering Contradiction:

Improvecontrol continuityVSAvoiddelay information accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent performs preliminary measurement of processing time at each communication apparatus and transmits this information to the control apparatus before control execution. This preliminary action ensures accurate, up-to-date delay information is available for control algorithms, eliminating deviation from actual delay while maintaining control continuity

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent continuously measures and updates processing time information at each communication apparatus throughout operation. This continuous measurement approach provides ongoing accurate delay information to the control apparatus, preventing deviation accumulation while maintaining uninterrupted control functionality

Inventive Principle:

Principle #20Continuity of useful action

Data Source

PatentUS11604445B2Control system and control method

Publication Date: 2023.03.14 NIPPON TELEGRAPH & TELEPHONE CORP

AI summary

A control system includes a control unit configured to control a target controlled apparatus, and at least one communication processing unit configured to execute communication processing in communication between the target controlled apparatus and the control unit, and in the control system, the communication processing unit sequentially measures a processing time of the communication processing and sequentially outputs delay information indicating the measured processing time to the control unit, and the control unit sequentially acquires the delay information from all of a plurality of the communication processing units, and sequentially updates delay information incorporated in a control algorithm for controlling the target controlled apparatus based on the acquired delay information.