The Sensors Layer defines all devices and documentation systems used by AOFS controllers to ensure safe operation, authoritative control, and auditable farm management.

All AOFS-compliant deployments must implement the sensors and documentation systems specified here.

AOFS sensors are classified by operational authority, not by technology type.

Sensor inputs fall into four functional roles:

• Safety enforcement (prevent damage or loss)
• Authoritative control inputs (drive irrigation decisions)
• Documentation & audit
• Optimization & research

AOFS controllers must never depend on remote systems to interpret or validate sensor data.

Purpose: Prevent equipment damage, flooding, dry-run pumps, and unsafe operating states.

Mandatory Measurements:

• Tank levels: LOW and FULL float switches
• Flow meters on main and zoned pipelines
• Pressure sensors on pumps and main distribution lines
• Rainfall measurement for irrigation lockout

Safety Requirements:

• These sensors must directly enforce Field Controller fail-safes
• Operation must be fully local and offline
• Loss or invalid data from these sensors must trigger safe shutdown or degraded mode

Purpose: Provide authoritative inputs for irrigation scheduling.

Required Measurements:

• Soil moisture (volumetric water content) per irrigation zone

Optional but Recommended:

• Soil temperature
• Electrical conductivity (salinity)

Placement Guidelines:

• At least one sensor per irrigation zone
• Additional sensors for heterogeneous fields
• Placement at crop-appropriate root depth

Purpose: Modify irrigation behavior and enforce environmental lockouts.

Required Measurements:

• Rainfall
• Ambient temperature
• Relative humidity

Optional Measurements:

• Wind speed
• Solar radiation / light intensity

Integration with AOFS:

• Rainfall triggers irrigation suspension
• Weather data refines thresholds and scheduling

Purpose: Track tank levels and authorize irrigation schedules.

Required Measurements:

• Tank LOW and FULL levels
• Flow rate in main and zoned pipelines

Optional Measurements:

• Tank temperature
• Salinity / water quality

Purpose: Optimize water sourcing from grid and local wells, based on availability probabilities.

Required Measurements (if grid water is available):

• Flow rate and pressure of grid water supply
• Availability signal (on/off)

Optional Measurements:

• Historical grid water supply patterns
• Probability of grid water availability in next hours

Integration & Control Logic:

• AOFS may delay pumping from well if there is a high probability of grid water availability
• Partial tank fill strategies: maintain mandatory minimum levels locally, avoid overfilling if grid water is likely
• Safety thresholds for tank levels must always be enforced, independent of probabilistic logic
• Logging of decisions, sensor readings, and probabilities is required for learning and optimization

Purpose: Protect electrical systems and support energy-aware operation.

Required Measurements:

• Pump power consumption
• Valve power consumption

Optional Measurements:

• Battery voltage and current
• Solar panel output

Integration:

• Low-voltage or overload conditions must trigger fail-safe behavior
• Energy data may inform event prioritization and anomaly detection

Purpose: Enable AOFS to safely use intermittent grid power and optimize energy costs.

Required Measurements (if grid is available):

• Grid voltage, current, and frequency
• Short-term fluctuations and harmonics
• Availability signal (on/off)

Optional Measurements:

• Historical grid availability patterns
• Probabilistic prediction of grid power for upcoming hours

Integration & Control Logic:

• AOFS must only allow grid power usage if parameters are within safe thresholds
• Automatic relays and actuators must cut off grid supply immediately on overvoltage, under-voltage, or unsafe frequency
• Predictive patterns can inform decisions, e.g., delaying high-load pump operations until grid is likely available
• All local safety thresholds remain authoritative and override probabilistic logic

Purpose: Capture critical farm activities not measurable by sensors.

AOFS treats human input as first-class data, equal to automated sensor measurements.

Examples of Loggable Events:

• Fertilizer application
• Manual irrigation or drainage
• Pest or disease treatment
• Planting, pruning, or harvest activities

Requirements:

• All events must be timestamped
• Events must be linked to a field or irrigation zone
• Operator identity must be recorded
• Full audit trail for edits or deletions is required

Purpose: Provide visual documentation for review, auditing, and optional analysis.

AOFS Scope:

• Still images only
• No video streaming requirements

Use Cases:

• Crop development tracking
• Soil surface condition documentation
• Pest or disease observation

Requirements:

• Images must be timestamped
• Camera ID and zone reference required
• Images stored locally on the Field Controller
• Optional synchronization with Farm and HQ Controllers

AI-based image analysis is explicitly optional and must not interfere with core logging or manual review.

• All sensor readings and human-input events must be logged locally
• Logs must include:
  • Timestamp
  • Source or sensor ID
  • Measured value or event data
  • Status or quality flags
• Synchronization follows AOFS federation rules
• Loss of connectivity must never result in data loss
• Grid power and water predictive measurements and decisions must be logged, including:
  1. Probability estimates for predictive logic
  2. Decisions made (pump on/off, fill levels)
  3. Outcome of the decisions for future optimization

• All sensors must be calibrated according to manufacturer specifications
• AOFS deployments must log:
  • Calibration events
  • Maintenance actions
  • Sensor replacements
• Calibration and maintenance logs are auditable and synchronized

Minimum mandatory implementation:

• Soil moisture sensors per irrigation zone
• Tank LOW and FULL level sensors
• Flow meters and pressure sensors on irrigation systems
• Power monitoring for pumps and valves
• Rainfall measurement for irrigation lockout

Optional sensors enhance optimization and research but do not affect baseline compliance.

• Field Controller Layer
• Farm Controller Layer (Local / Federated)
• Hydraulic & Water Systems
• Electrical & Control Interfaces