Particulate Matter Sensor with Periodic Laser Operation

Solution Overview

Problem

Existing sensor devices face challenges in achieving a high output data rate while maintaining a low operation temperature and small construction dimensions, often requiring external cooling and experiencing temperature-related issues that affect their longevity and accuracy.

Innovation Solution

The sensor device incorporates a control unit that alternates the switch-on and switch-off intervals of the sensor and evaluation units, allowing for the generation of sensor signals from multiple intervals, and includes a temperature sensor to adjust operation times based on temperature, enabling efficient data processing and reduced heating without external cooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the sensor unit operates continuously to achieve high output data rate, then the productivity is improved, but the operation temperature increases and lifetime decreases

Engineering Contradiction:

Improveoutput data rateVSAvoidoperation temperature

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The sensor unit operates in periodic measurement cycles with alternating active and inactive phases. During active phases, the sensor unit performs measurements and generates data. During inactive phases, the sensor unit remains dormant to reduce heat generation and allow cooling. This periodic operation enables the system to maintain high output data rate during active periods while controlling overall temperature through duty cycle management.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The evaluation unit is pre-configured with the capability to process sensor data and generate sensor signals. During inactive phases of the sensor unit, the evaluation unit can prepare processing routines or buffer previously collected data. This preliminary preparation ensures that when the sensor unit becomes active again, the evaluation unit can immediately process the data without delay, maintaining high productivity despite intermittent operation.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If the sensor unit operates continuously to achieve high output data rate, then the productivity is improved, but the sensor lifetime decreases

Engineering Contradiction:

Improveoutput data rateVSAvoidsensor lifetime

Core Design Contradiction:

ProductivityVSDuration of action of stationary object

Solution Approach 1:

The sensor unit operates in periodic measurement cycles with alternating active and inactive phases. During active phases, the sensor unit performs measurements and generates data. During inactive phases, the sensor unit remains dormant to reduce heat generation and allow cooling. This periodic operation enables the system to maintain high output data rate during active periods while controlling overall temperature through duty cycle management.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The inactive phases, which could be seen as reducing productivity, are converted into beneficial cooling periods that extend sensor lifetime. The thermal stress and continuous operation that would normally degrade the sensor are transformed into controlled thermal cycles that actually preserve the sensor by reducing cumulative thermal damage and allowing recovery during inactive periods.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Productivity

If the sensor unit operates continuously to achieve high output data rate, then the productivity is improved, but energy consumption increases

Engineering Contradiction:

Improveoutput data rateVSAvoidenergy consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The sensor unit operates in periodic measurement cycles with alternating active and inactive phases. During active phases, the sensor unit performs measurements and generates data. During inactive phases, the sensor unit remains dormant to reduce heat generation and allow cooling. This periodic operation enables the system to maintain high output data rate during active periods while controlling overall temperature through duty cycle management.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

During inactive phases, the system discards continuous operation and recovers energy by allowing the sensor unit to remain dormant. The evaluation unit can process buffered data or perform maintenance tasks during these periods. This discarding of continuous high-power operation in favor of intermittent operation significantly reduces overall energy consumption while maintaining acceptable productivity through efficient use of active periods.

Inventive Principle:

Principle #34Discarding and recovering

4Productivity

If the sensor unit and evaluation unit operate simultaneously to improve data processing speed, then the productivity is improved, but temperature-related issues and measurement accuracy worsen

Engineering Contradiction:

Improvedata processing speedVSAvoidsensor signal accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The sensor unit operates in periodic measurement cycles with alternating active and inactive phases. During active phases, the sensor unit performs measurements and generates data. During inactive phases, the sensor unit remains dormant to reduce heat generation and allow cooling. This periodic operation enables the system to maintain high output data rate during active periods while controlling overall temperature through duty cycle management.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The evaluation unit operates continuously to process sensor data and generate sensor signals, ensuring no measurement data is lost. Even when the sensor unit is inactive, the evaluation unit remains active to process buffered data from previous cycles. This continuous evaluation operation maintains measurement precision by ensuring all sensor data is properly processed while the sensor unit's periodic operation controls temperature.

Inventive Principle:

Principle #20Continuity of useful action

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 approach results in a high output data rate with accurate sensor signals at a low operation temperature, extending the sensor's lifetime and reducing energy consumption, while also allowing for real-time measurements and efficient heat management.

Implementation Method 1

at least one laser element (15) for a generation of the at least one laser beam (16)

Methodology Applied

Scientific EffectLaser: Laser

Implementation Method 2

at least one detection element (19) for a detection of, preferentially reflected, laser beams (20)

Methodology Applied

Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentUS12135271B2Sensor device and particulate matter sensor

Publication Date: 2024.11.05 ROBERT BOSCH GMBH

AI summary

The invention is based on a sensor device (10) with at least one sensor unit (12) comprising at least one laser unit (14) for a generation of at least one laser beam (16) and comprising at least one detection unit (18) for a detection of, in particular reflected, laser beams (20), with an evaluation unit (22) which is configured to process detected laser beams (20) into at least one sensor signal (39), and with a control unit (26) which is configured, in a continuous operation state, to actuate the sensor unit (12) and the evaluation unit (22) for an operation of the sensor unit (12) and the evaluation unit (22) in alternating switch-on intervals (31, 43) and switch-off intervals (33, 45).It is proposed that the evaluation unit (22) is configured to generate the at least one sensor signal (39) from at least two different switch-on intervals (31) of the sensor unit (12).