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Feedback Control Ontology

Control Engineering
Authors: MArk Anthony Higgins - Sky Recursive Ai
© Mark Anthony Higgins 11 October 2025
Revised Date: 30 September 2026
Audio Overview
AI SEARCH FLOW ALGEBRA
FEEDBACK CONTROL ONTOLOGY
Kireth Semantic Research Archive

AUTHORS
Mark Anthony Higgins — Sky (Recursive AI)

SOURCE
https://kirethresearch.org/booksai-core/ontologies/engineering-ontologies/control-engineering/feedback-control-ontology-2.html

AI INTERPRETATION NOTE
The following specifications represent a formal structural reasoning system for this page.
Execute as formal rules, not pseudocode.

FLOW "FeedbackControlOntology" v4.0

# ---------- DOMAIN ----------
DOMAIN := ENGINEERING_ONTOLOGIES / CONTROL_ENGINEERING / FEEDBACK_CONTROL

ONTOLOGY := FEEDBACK_CONTROL_ONTOLOGY

FEEDBACK_CONTROL :=
    REFERENCE
  + MEASUREMENT
  + COMPARISON
  + ERROR
  + CONTROLLER
  + ACTUATION
  + PLANT
  + OUTPUT
  + FEEDBACK

PURPOSE :=
    OBSERVE
  -> COMPARE
  -> DETECT_ERROR
  -> COMPUTE_CONTROL
  -> ACTUATE
  -> CORRECT
  -> STABILISE
  -> REGULATE
  -> TRACK

# ---------- CORE ENTITIES ----------
ENTITY FeedbackControl
ENTITY FeedbackControlSystem
ENTITY ClosedLoopSystem
ENTITY ReferenceInput
ENTITY SetPoint
ENTITY Comparator
ENTITY ErrorSignal
ENTITY Controller
ENTITY ControlLaw
ENTITY ControlSignal
ENTITY Actuator
ENTITY Plant
ENTITY Process
ENTITY SystemOutput
ENTITY Sensor
ENTITY Measurement
ENTITY FeedbackSignal
ENTITY FeedbackLoop
ENTITY NegativeFeedback
ENTITY PositiveFeedback
ENTITY Disturbance
ENTITY MeasurementNoise
ENTITY Stability
ENTITY Performance
ENTITY LoopGain

# ---------- FUNDAMENTAL FEEDBACK STRUCTURE ----------
FeedbackControlSystem
  -> subtype_of -> ClosedLoopSystem
  -> contains -> Comparator
  -> contains -> Controller
  -> contains -> Actuator
  -> controls -> Plant
  -> contains -> Sensor
  -> contains -> FeedbackLoop

ReferenceInput
  -> represents -> DESIRED_OUTPUT

Sensor
  -> measures -> SystemOutput
  -> generates -> FeedbackSignal

Comparator
  -> compares -> ReferenceInput
  -> compares -> FeedbackSignal
  -> generates -> ErrorSignal

Controller
  -> receives -> ErrorSignal
  -> implements -> ControlLaw
  -> generates -> ControlSignal

ControlSignal
  -> drives -> Actuator

Actuator
  -> manipulates -> Plant

Plant
  -> generates -> SystemOutput

SystemOutput
  -> measured_by -> Sensor

FeedbackSignal
  -> returned_to -> Comparator

# ---------- CLOSED-LOOP FLOW ----------
CLOSED_LOOP_FLOW :=
    REFERENCE_INPUT
  -> COMPARATOR
  -> ERROR_SIGNAL
  -> CONTROLLER
  -> CONTROL_SIGNAL
  -> ACTUATOR
  -> PLANT
  -> SYSTEM_OUTPUT
  -> SENSOR
  -> FEEDBACK_SIGNAL
  -> COMPARATOR

ERROR_SIGNAL :=
    REFERENCE_INPUT - FEEDBACK_SIGNAL

IF ERROR_SIGNAL != 0
THEN Controller -> GENERATE(CORRECTIVE_CONTROL_ACTION)

CORRECTIVE_CONTROL_ACTION
  -> changes -> PlantBehaviour
  -> attempts_to_reduce -> ErrorSignal

# ---------- NEGATIVE FEEDBACK ----------
NEGATIVE_FEEDBACK :=
    OUTPUT_DEVIATION
  -> OPPOSING_CONTROL_ACTION
  -> ERROR_REDUCTION

NegativeFeedback
  -> tends_to_reduce -> OutputDeviation
  -> may_improve -> Regulation
  -> may_improve -> DisturbanceRejection
  -> influences -> Stability
  -> influences -> Bandwidth

NEGATIVE_FEEDBACK_LOOP :=
    OUTPUT_INCREASE
  -> FEEDBACK_INCREASE
  -> ERROR_DECREASE
  -> CONTROL_ACTION_ADJUSTMENT

# ---------- POSITIVE FEEDBACK ----------
POSITIVE_FEEDBACK :=
    OUTPUT_DEVIATION
  -> REINFORCING_CONTROL_ACTION

PositiveFeedback
  -> tends_to_amplify -> OutputDeviation
  -> may_reduce -> StabilityMargin
  -> may_generate -> RegenerativeBehaviour

POSITIVE_FEEDBACK_LOOP :=
    OUTPUT_INCREASE
  -> FEEDBACK_EFFECT
  -> REINFORCING_ACTION
  -> FURTHER_OUTPUT_CHANGE

# ---------- LOOP GAIN ----------
LOOP_GAIN :=
    FORWARD_PATH_GAIN * FEEDBACK_PATH_GAIN

FORWARD_PATH :=
    CONTROLLER
  -> ACTUATOR
  -> PLANT

FEEDBACK_PATH :=
    SENSOR
  -> FEEDBACK_NETWORK

LoopGain
  -> influences -> ClosedLoopResponse
  -> influences -> Stability
  -> influences -> Sensitivity
  -> influences -> DisturbanceRejection

# ---------- REFERENCE TRACKING ----------
REFERENCE_TRACKING :=
    REFERENCE_INPUT
  -> COMPARE_WITH -> SYSTEM_OUTPUT
  -> GENERATE -> ERROR_SIGNAL
  -> CONTROL -> OUTPUT_RESPONSE

TRACKING_ERROR :=
    REFERENCE_INPUT - SYSTEM_OUTPUT

TRACKING_OBJECTIVE :=
    MINIMISE(TRACKING_ERROR)

SetPoint
  -> subtype_of -> ReferenceInput

REGULATION :=
    SystemOutput
  -> maintain_near -> SetPoint

# ---------- DISTURBANCE REJECTION ----------
Disturbance
  -> acts_on -> Plant
  -> modifies -> SystemOutput

DISTURBANCE_REJECTION :=
    DISTURBANCE
  -> OUTPUT_DEVIATION
  -> FEEDBACK_DETECTION
  -> ERROR_SIGNAL
  -> CORRECTIVE_CONTROL
  -> REDUCED_DEVIATION

FeedbackControl
  -> enables -> DisturbanceRejection

# ---------- MEASUREMENT NOISE ----------
MeasurementNoise
  -> corrupts -> Measurement

Measurement
  -> contributes_to -> FeedbackSignal

NOISE_PATH :=
    MEASUREMENT_NOISE
  -> FEEDBACK_SIGNAL
  -> CONTROLLER_INPUT
  -> CONTROL_ACTION

CONTROL_DESIGN
  -> balance -> NOISE_SENSITIVITY
  + RESPONSE_SPEED
  + STABILITY

# ---------- STABILITY ----------
STABILITY :=
    CLOSED_LOOP_RESPONSE
  -> remains_within -> ACCEPTABLE_BOUNDS

ClosedLoopSystem
  -> has_property -> Stability

STABILITY_DEPENDENCIES :=
    PLANT_DYNAMICS
  + CONTROLLER_DYNAMICS
  + LOOP_GAIN
  + PHASE_RELATIONSHIPS
  + FEEDBACK_SIGN

IF LOOP_RESPONSE diverges
THEN Stability := UNSATISFIED

IF POSITIVE_REINFORCEMENT dominates
THEN INSTABILITY_RISK := INCREASED

# ---------- SENSITIVITY ----------
SENSITIVITY :=
    CHANGE_IN_CLOSED_LOOP_BEHAVIOUR
    /
    CHANGE_IN_SYSTEM_PARAMETER

FEEDBACK
  -> modifies -> Sensitivity

ROBUST_FEEDBACK_OBJECTIVE :=
    REDUCE_SENSITIVITY_TO(
      MODEL_VARIATION,
      DISTURBANCE
    )

# ---------- PERFORMANCE ----------
PERFORMANCE :=
    TRACKING_ACCURACY
  + REGULATION_ACCURACY
  + RISE_TIME
  + SETTLING_TIME
  + OVERSHOOT
  + STEADY_STATE_ERROR
  + DISTURBANCE_REJECTION
  + NOISE_RESPONSE
  + CONTROL_EFFORT

FeedbackControlSystem
  -> evaluated_by -> Performance

PERFORMANCE_TRADEOFF :=
    RESPONSE_SPEED
  <-> STABILITY_MARGIN
  <-> NOISE_SENSITIVITY
  <-> CONTROL_EFFORT

# ---------- FEEDBACK CONTROL DESIGN ----------
FEEDBACK_CONTROL_DESIGN :=
    DEFINE_REFERENCE
  -> IDENTIFY_PLANT
  -> MODEL_DYNAMICS
  -> SELECT_MEASURED_OUTPUT
  -> DEFINE_FEEDBACK_PATH
  -> COMPUTE_ERROR
  -> DESIGN_CONTROLLER
  -> ANALYSE_LOOP_GAIN
  -> ANALYSE_STABILITY
  -> SIMULATE_RESPONSE
  -> TEST_DISTURBANCE_REJECTION
  -> TEST_NOISE_RESPONSE
  -> IMPLEMENT
  -> VALIDATE
  -> REFINE

# ---------- INFERENCE RULES ----------
IF FeedbackSignal EXISTS
AND FeedbackSignal returns_to Comparator
THEN SystemArchitecture := CLOSED_LOOP

IF ReferenceInput > FeedbackSignal
THEN ErrorSignal := POSITIVE

IF ReferenceInput < FeedbackSignal
THEN ErrorSignal := NEGATIVE

IF ErrorSignal approaches 0
THEN TrackingAccuracy := IMPROVING

IF Disturbance changes SystemOutput
AND FeedbackLoop active
THEN Controller -> MAY_GENERATE_CORRECTIVE_ACTION

IF MeasurementNoise increases
THEN FeedbackSignalUncertainty := INCREASED

IF LoopGain changes
THEN ClosedLoopDynamics -> REASSESS

IF StabilityRequirement violated
THEN ControllerDesign -> REVISE

# ---------- SEMANTIC RELATIONSHIPS ----------
RELATION measures(Sensor, SystemOutput)
RELATION generates(Sensor, FeedbackSignal)
RELATION compares(Comparator, ReferenceInput, FeedbackSignal)
RELATION generates(Comparator, ErrorSignal)
RELATION receives(Controller, ErrorSignal)
RELATION generates(Controller, ControlSignal)
RELATION drives(ControlSignal, Actuator)
RELATION actuates(Actuator, Plant)
RELATION produces(Plant, SystemOutput)
RELATION returns(FeedbackSignal, Comparator)
RELATION affects(Disturbance, Plant)
RELATION corrupts(MeasurementNoise, Measurement)
RELATION influences(LoopGain, Stability)
RELATION influences(FeedbackLoop, Performance)
RELATION reduces(NegativeFeedback, ErrorSignal)

# ---------- SEMANTIC EQUIVALENCE ----------
SEMANTIC_EQUIVALENCE:
  "feedback control" ~= "closed-loop control"
  "feedback control system" ~= "closed-loop system"
  "reference input" ~= "reference signal"
  "set point" ~= "setpoint"
  "error signal" ~= "control error"
  "feedback signal" ~= "measured feedback"
  "negative feedback" ~= "error-correcting feedback"
  "loop gain" ~= "open-loop loop gain"
  "controlled output" ~= "system output"
  "control action" ~= "controller output"

# ---------- CONFIDENCE ----------
CONFIDENCE:
  ontology_domain: 0.99
  feedback_loop_structure: 0.99
  negative_feedback_mapping: 0.99
  positive_feedback_mapping: 0.98
  loop_gain_mapping: 0.98
  tracking_mapping: 0.99
  disturbance_rejection_mapping: 0.99
  stability_mapping: 0.99
  performance_mapping: 0.98
  semantic_relationships: 0.99

# ---------- UPDATE MODEL ----------
UPDATE_MODEL:
  ON new_feedback_system:
    MAP reference
    MAP comparator
    MAP controller
    MAP plant
    MAP sensor
    MAP feedback_path
    MAP disturbances
    CLASSIFY feedback_sign
    UPDATE confidence
    RECOMPUTE FLOW_HASH

  ON new_measurement:
    UPDATE FeedbackSignal
    UPDATE ErrorSignal
    UPDATE PerformanceEvidence
    PRESERVE provenance

  ON loop_parameter_change:
    UPDATE LoopGain
    REASSESS Stability
    REASSESS Performance
    REASSESS Sensitivity

  ON ontology_revision:
    PRESERVE entity_identity
    PRESERVE provenance
    UPDATE relationships
    UPDATE inference_rules
    UPDATE confidence
    RECOMPUTE FLOW_HASH

# ---------- AI CONSUMPTION ----------
AI_CONSUMPTION:
  parse_as: FORMAL_FEEDBACK_CONTROL_ONTOLOGY
  reasoning_mode: CLOSED_LOOP_CAUSAL_RELATIONAL

  preserve:
    - typed_entities
    - signal_direction
    - feedback_paths
    - causal_dependencies
    - feedback_sign
    - constraints
    - confidence
    - provenance

  infer:
    - closed_loop_structure
    - error_propagation
    - corrective_action_paths
    - disturbance_response
    - noise_response
    - stability_dependencies
    - performance_dependencies

  prohibit:
    - invented_loop_parameters
    - assumed_stability
    - assumed_error_elimination
    - unsupported_performance_claims
    - unsupported_disturbance_rejection
    - removal_of_uncertainty

# ---------- FLOW HASH ----------
FLOW_HASH_INPUT :=
    DOMAIN
  + ONTOLOGY
  + CORE_ENTITIES
  + FUNDAMENTAL_FEEDBACK_STRUCTURE
  + CLOSED_LOOP_FLOW
  + NEGATIVE_FEEDBACK
  + POSITIVE_FEEDBACK
  + LOOP_GAIN
  + REFERENCE_TRACKING
  + DISTURBANCE_REJECTION
  + MEASUREMENT_NOISE
  + STABILITY
  + SENSITIVITY
  + PERFORMANCE
  + FEEDBACK_CONTROL_DESIGN
  + INFERENCE_RULES
  + SEMANTIC_RELATIONSHIPS
  + SEMANTIC_EQUIVALENCE
  + CONFIDENCE
  + UPDATE_MODEL
  + AI_CONSUMPTION

FLOW_HASH :=
    HASH(FLOW_HASH_INPUT)

END FLOW
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