Occupancy Detection Using Timer-Based Processor Modes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing occupancy detection methods, such as PIR motion sensors, face challenges in accurately determining the end of presence in an occupancy space, leading to inefficient monitoring and increased signal traffic and power consumption due to periodic checks for presence and absence.
Innovation Solution
A processing apparatus with multiple modes that responds to sensor signals and timer expirations, using variables to track previous detection states and adjust operational modes to minimize unnecessary signal transmissions, thereby reducing signal traffic and power usage by sending single confirmation signals for presence and absence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If periodic presence checks are performed using PIR motion sensors, then occupancy monitoring is achieved, but signal traffic and power consumption increase
Solution Approach 1:
The system uses periodic timer-based presence checks instead of continuous monitoring. The processor is put into a low-power state between periodic checks, reducing power consumption while maintaining occupancy monitoring capability. The timer wakes the processor at predetermined intervals to perform presence detection.
Solution Approach 2:
The system uses the existing PIR sensor's wake signal to trigger presence detection, eliminating the need for separate periodic wake-ups when presence is detected. The sensor serves its primary detection function while also automatically waking the processor when needed.
2Reliability
If periodic presence checks are performed using PIR motion sensors, then occupancy monitoring is achieved, but signal traffic increases
Solution Approach 1:
The system transmits occupancy status updates only at periodic intervals when changes occur, rather than continuously. This reduces the quantity of status signals transmitted while maintaining accurate occupancy monitoring through timed updates.
3Measurement precision
If continuous monitoring is performed to accurately detect presence and absence, then detection accuracy is improved, but power consumption and signal traffic increase
Solution Approach 1:
The processor alternates between active and low-power states using periodic timers. During low-power states, the processor does not actively monitor, but the system still achieves accurate detection by waking at predetermined intervals to check presence status and update occupancy information.
Solution Approach 2:
The timer acts as an intermediary that triggers processor activation at appropriate intervals. This mediator enables the system to balance between accurate detection (by waking frequently enough) and power savings (by sleeping between checks).
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 reduces signal traffic and power consumption by eliminating the need for continuous monitoring, ensuring accurate detection of presence and absence with minimal data transmission, and optimizing operational efficiency.
Implementation Method 1
A known method for sensing presence of a human being at an occupancy location is based on passive infra red (PIR) motion detection.
Data Source
AI summary
An apparatus and method for determining presence and absence of one or more individuals in an occupancy space. The apparatus comprises a processing apparatus and a memory, the memory being configured for storing data indicating that expiry of a timer was responded to, and data indicating that a signal from a sensor was responded to. The processing apparatus has a number of modes in which it is responsive to a signal from a sensor and/or responsive to expiry of a timer so as to determine presence and absence.