Telematics Network Access Device Sleep Cycle Adjustment

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Solution Overview

Problem

The network access device (NAD) of a telematics unit in a vehicle dissipates excessive current when in a 'No Service' area, leading to rapid battery drain and premature entry into the Off State, rendering it unable to perform services when communication service is unavailable.

Innovation Solution

Implementing a Standby Counter that adjusts the sleep cycle duration based on current dissipation rates, using a No Service Factor to decrement the counter more slowly in 'No Service' areas, thereby preventing excessive battery drain.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the NAD operates in Standby State with a fixed sleep cycle, then the device can perform services when awakened, but the battery drains excessively in No Service areas causing premature entry into Off State

Engineering Contradiction:

Improveservice availabilityVSAvoidbattery drain

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the sleep cycle value adjustable rather than fixed. The system dynamically changes the sleep cycle duration based on service availability: using a first sleep cycle value when service is available and a second, longer sleep cycle value when service is unavailable. This dynamic adaptation resolves the contradiction by extending battery life in No Service areas while maintaining service responsiveness when available.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of sleep cycle duration based on operating conditions. By monitoring service availability and adjusting the sleep cycle value accordingly, the system optimizes power consumption. When service is unavailable, the longer sleep cycle reduces wake-up frequency and battery drain; when service is available, the shorter cycle ensures timely service response.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If the NAD wakes up frequently to check for service availability, then the unit can respond to service requests, but the current dissipation increases to 200-300 mA in No Service areas

Engineering Contradiction:

Improveservice response capabilityVSAvoidcurrent dissipation

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

The system dynamically adjusts the sleep cycle duration based on whether service is available. When service becomes unavailable, the sleep cycle is extended, reducing the frequency of wake-ups and associated current dissipation. This dynamic adjustment maintains service response capability when available while minimizing energy loss when service is unavailable.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system takes preliminary action by detecting service availability status and proactively adjusting the sleep cycle before excessive battery drain occurs. By extending the sleep cycle when service becomes unavailable, the system prevents the harmful effect of excessive current dissipation (200-300 mA) that would otherwise occur with frequent wake-up attempts in No Service areas.

Inventive Principle:

Principle #9Preliminary anti-action

3Duration of action of stationary object

If the telematics unit uses a longer sleep cycle to conserve battery, then battery drain is reduced, but the unit may miss service requests or commands from the call center

Engineering Contradiction:

Improvebattery durationVSAvoidservice execution

Core Design Contradiction:

Duration of action of stationary objectVSReliability

Solution Approach 1:

The system changes the sleep cycle parameter based on service availability conditions. When service is available, a shorter sleep cycle ensures the unit wakes up to receive and execute service requests. When service becomes unavailable, the sleep cycle is extended to conserve battery. This conditional parameter adjustment resolves the contradiction by maintaining service reliability when possible while extending battery duration when service is unavailable.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS8000842B2Method to prevent excessive current drain of telematics unit network access device

Publication Date: 2011.08.16 GENERAL MOTORS LLC

AI summary

The disclosed examples illustrate a system and method that prevent excessive current drain through the network access device (NAD) of a telematics unit and provide flexible discontinuous-receive management. Normally, when in a Standby State and where communication service is unavailable, the NAD may dissipate current at rate many times more than where communication service is available. A Standby Counter provides the length of the time interval for Standby State or the sleep cycle. Certain of the disclosed examples prevent excessive vehicle battery drain by operating the telematics unit in a first mode wherein a sleep cycle value of the telematics unit is above a first predetermined threshold, and if the communication service is available, operating the telematics unit in a second mode wherein a sleep cycle value is in a range from zero to the first predetermined threshold.