SILVIA Core ApiNavigation Reference

Version: 3.1

Namespace: CognitiveCode.Silvia.Api

SILVIA's Navigation API is a high-performance autonomous vehicle guidance system designed for drones, ground vehicles, watercraft, and submarines. It implements multi-modal sensor fusion (GPS, IMU, SLAM, compass), PID control, waypoint following, formation flight, and terrain following using a zero-allocation struct-based component architecture.

This is not just a navigation library. It's a complete autonomous vehicle control stack that transforms raw sensor data into precise vehicle actuation commands. From precision agriculture drones to tactical UAV swarms to autonomous delivery robots, SILVIA Navigation provides the sensor fusion, guidance algorithms, and control systems required for production autonomous vehicles.

Architectural Philosophy: Composition Over Hierarchy

Traditional autonomous vehicle systems use object-oriented hierarchies that create GC pressure and allocation overhead. SILVIA Navigation uses value-type component composition:

Component-Based Architecture:

All navigation components are structs (value types)
Zero heap allocations during navigation updates
Aggressive inlining for critical paths
Composition pattern with embedded components

Multi-Modal Sensor Fusion:

GPS Navigation - Geographic positioning and waypoint following
SLAM Navigation - Visual/LiDAR-based local positioning
Hybrid Mode - Weighted fusion based on sensor confidence
IMU Integration - Orientation and acceleration

Advanced Navigation Modes:

Manual - Direct control inputs
GPS - Geographic waypoint following
SLAM - Vision-based autonomous navigation
Hybrid - Multi-sensor fusion
Terrain Following - Automatic altitude adjustment
Formation Flight - Swarm coordination
Emergency - Fail-safe procedures

Vehicle Types & Capabilities

Supported Vehicles:

VehicleType.Drone - Quadcopters, fixed-wing UAVs
VehicleType.GroundVehicle - Rovers, autonomous cars
VehicleType.WaterCraft - Surface vessels, boats
VehicleType.Submarine - Underwater autonomous vehicles

Control Systems:

Position PID controller (X, Y, Z)
Attitude PID controller (Roll, Pitch, Yaw)
Waypoint follower with radius-based switching
Collision avoidance with obstacle detection
Battery management with low-power adaptation
Weather compensation (wind, air density)
Payload effects and center-of-mass adjustment

Modern Use Cases

1. Autonomous Delivery Drone with GPS Waypoints

Deploy delivery drone with automatic waypoint following and emergency procedures.

csharp

var nav = core.ApiNavigation();

// Create drone navigation entity
int droneId = nav.CreateNavigationEntity(
    VehicleType.Drone,
    maxSpeed: 15.0f,        // 15 m/s
    maxAcceleration: 5.0f,  // 5 m/s²
    collisionRadius: 2.0f   // 2 meter safety bubble
);

// Set GPS navigation mode
nav.SetNavigationMode(droneId, NavigationMode.GPS);

// Define delivery route
GeoCoordinate[] waypoints = new GeoCoordinate[] {
    new GeoCoordinate(37.7749, -122.4194, 50),  // Take-off
    new GeoCoordinate(37.7849, -122.4094, 100), // Cruise altitude
    new GeoCoordinate(37.7949, -122.3994, 100), // Waypoint
    new GeoCoordinate(37.8049, -122.3894, 50),  // Descent
    new GeoCoordinate(37.8049, -122.3894, 10)   // Landing
};
nav.SetWaypoints(droneId, waypoints);

// Update navigation loop (60 Hz)
void FixedUpdate() {
    nav.UpdateNavigation(Time.fixedDeltaTime);
    
    // Get current state
    NavigationState state = nav.GetNavigationState(droneId);
    core.ApiApp().SetTextOutput(
        $"Position: {state.Position}\n" +
        $"Velocity: {state.Velocity.Length()} m/s"
    );
}

2. UAV Swarm Formation Flight

Coordinate multiple drones in V-formation using relative positioning.

csharp

var nav = core.ApiNavigation();

// Create leader drone
int leaderId = nav.CreateNavigationEntity(VehicleType.Drone, maxSpeed: 20.0f);
nav.SetNavigationMode(leaderId, NavigationMode.GPS);

// Create follower drones in formation
int[] followerIds = new int[4];
for (int i = 0; i < 4; i++) {
    followerIds[i] = nav.CreateNavigationEntity(VehicleType.Drone, maxSpeed: 20.0f);
    
    // Enable formation flight
    float offsetX = (i % 2 == 0) ? -10.0f : 10.0f;  // Left/Right
    float offsetZ = -(i / 2 + 1) * 8.0f;           // Behind leader
    
    nav.EnableFormationFlight(
        followerIds[i],
        formationId: 1,
        positionInFormation: i + 1,
        offsetX: offsetX,
        offsetY: 0.0f,
        offsetZ: offsetZ
    );
}

// Leader navigates, followers maintain formation automatically
nav.SetTargetPosition(leaderId, 37.7849, -122.4094, 100);

3. Terrain-Following Drone for Mapping

Automatically maintain altitude above terrain while mapping.

csharp

var nav = core.ApiNavigation();

int mapperId = nav.CreateNavigationEntity(VehicleType.Drone, maxSpeed: 12.0f);

// Enable terrain following mode
nav.EnableTerrainFollowing(
    mapperId,
    desiredAltitude: 50.0f,    // 50m above terrain
    terrainClearance: 20.0f    // Minimum 20m clearance
);

// Update terrain data from LiDAR/altimeter
void ProcessTerrainSensor(float terrainHeight, Vector3 terrainNormal) {
    nav.UpdateTerrainData(
        mapperId,
        terrainHeight,
        terrainNormal.X,
        terrainNormal.Y,
        terrainNormal.Z
    );
    
    // Navigation automatically adjusts altitude
    nav.UpdateNavigation(Time.deltaTime);
}

Combine GPS and SLAM for robust indoor/outdoor navigation.

csharp

var nav = core.ApiNavigation();

int roverId = nav.CreateNavigationEntity(
    VehicleType.GroundVehicle,
    maxSpeed: 5.0f,
    maxAcceleration: 2.0f
);

// Use hybrid GPS + SLAM navigation
nav.SetNavigationMode(roverId, NavigationMode.Hybrid);

// Update GPS data (outdoor)
nav.UpdateGpsData(
    roverId,
    latitude: 37.7749,
    longitude: -122.4194,
    altitude: 10.0,
    accuracy: 2.5f,
    velocityX: 1.0f,
    velocityY: 0.0f,
    velocityZ: 0.5f
);

// Update SLAM data (indoor)
nav.UpdateSlamData(
    roverId,
    slamPosition: new Vector3(10.5f, 0.2f, 5.3f),
    slamOrientation: Quaternion.Identity,
    slamConfidence: 0.85f
);

// Hybrid mode automatically weights GPS vs SLAM based on confidence
nav.UpdateNavigation(Time.deltaTime);

5. Emergency Landing with Battery Management

Trigger emergency landing when battery is low.

csharp

var nav = core.ApiNavigation();

int droneId = nav.CreateNavigationEntity(VehicleType.Drone);

// Update battery status
nav.UpdateBatteryData(droneId, voltage: 11.2f, current: 5.5f);

// Check battery and trigger emergency if needed
void MonitorBattery(int entityId) {
    NavigationState state = nav.GetNavigationState(entityId);
    
    // Assuming battery voltage in custom data
    float voltage = GetBatteryVoltage();
    
    if (voltage < 11.0f) { // Critical threshold
        core.ApiApp().SetTextOutput("CRITICAL: Low battery, initiating emergency landing");
        nav.TriggerEmergency(entityId);
        
        // Emergency mode automatically hovers/descends
    }
}

6. Manual Control with Override

Switch between autonomous and manual control.

csharp

var nav = core.ApiNavigation();

int droneId = nav.CreateNavigationEntity(VehicleType.Drone);

// Autonomous GPS navigation
nav.SetNavigationMode(droneId, NavigationMode.GPS);
nav.SetTargetPosition(droneId, 37.7849, -122.4094, 100);

// Manual override from joystick
void OnManualInput(float joyX, float joyY, float joyThrottle) {
    nav.SetManualControl(
        droneId,
        thrustX: joyX,
        thrustY: 0.0f,
        thrustZ: joyY,
        throttle: joyThrottle
    );
    // Automatically switches to Manual mode
}

// Emergency stop button
void OnEmergencyStop() {
    nav.EmergencyStop(droneId); // Immediately zeros all thrust
}

Core Concepts

Navigation entities are the core abstraction representing individual autonomous vehicles.

Entity Creation:

csharp

int entityId = nav.CreateNavigationEntity(
    vehicleType: VehicleType.Drone,
    maxSpeed: 15.0f,           // Maximum speed in m/s
    maxAcceleration: 5.0f,     // Maximum acceleration in m/s²
    collisionRadius: 2.0f      // Collision detection radius in meters
);

Entity Management:

csharp

// Get all active entities
int[] activeEntities = nav.GetActiveEntities();

// Get entity diagnostics
string diagnostics = nav.GetEntityDiagnostics(entityId);
core.ApiApp().SetTextOutput(diagnostics);

// Remove entity
bool removed = nav.RemoveEntity(entityId);

Configuration:

csharp

// Each entity has:
// - VehicleConfiguration (max speed, mass, PID gains, collision radius)
// - NavigationState (position, velocity, orientation, sensors)
// - ControlInputs (thrust, torque, throttle)
// - Navigation components (GPS, SLAM, PID controllers, etc.)

NavigationMode.Manual:

Direct control via SetManualControl()
No autonomous navigation
Useful for RC override

NavigationMode.GPS:

Geographic waypoint following
Uses Haversine formula for distance calculation
Automatic bearing computation

NavigationMode.SLAM:

Visual/LiDAR-based local navigation
Maintains local map origin
Suitable for indoor or GPS-denied environments

NavigationMode.Hybrid:

Weighted fusion of GPS and SLAM
Automatically balances based on sensor confidence
Seamless indoor/outdoor transitions

NavigationMode.TerrainFollowing:

Maintains altitude above terrain
Uses terrain normal for slope compensation
Ideal for mapping and surveying

NavigationMode.FormationFlight:

Maintains relative position to leader
Automatic formation offset calculation
Swarm coordination

NavigationMode.Emergency:

Fail-safe procedures
Hover or controlled descent
Triggered manually or by battery/sensor failures

GPS Sensor Data:

csharp

nav.UpdateGpsData(
    entityId,
    latitude: 37.7749,
    longitude: -122.4194,
    altitude: 100.0,
    accuracy: 2.5f,        // GPS accuracy in meters
    velocityX: 5.0f,       // GPS velocity components in m/s
    velocityY: 0.5f,
    velocityZ: 2.0f
);

IMU Sensor Data:

csharp

nav.UpdateImuData(
    entityId,
    accelX: 0.1f,    // Accelerometer in m/s²
    accelY: 9.8f,
    accelZ: 0.0f,
    gyroX: 0.0f,     // Gyroscope in rad/s
    gyroY: 0.05f,
    gyroZ: 0.0f
);

Compass Data:

csharp

nav.UpdateCompassData(
    entityId,
    heading: 45.0  // Compass heading in degrees
);

SLAM Data (Custom Integration):

csharp

// Assuming SLAM system provides position and orientation
Vector3 slamPosition = GetSLAMPosition();
Quaternion slamOrientation = GetSLAMOrientation();
float slamConfidence = GetSLAMConfidence();

nav.UpdateSlamData(
    entityId,
    slamPosition,
    slamOrientation,
    slamConfidence
);

Sensor Fusion Logic:

GPS + IMU → Fused position and velocity
Compass → Heading correction
SLAM → Indoor positioning when GPS unavailable
Hybrid mode → Weighted average based on confidence

4. PID Control System

Position PID Controller:

Controls X, Y, Z position
Output: Desired thrust vector
Configurable gains (Kp, Ki, Kd)

Attitude PID Controller:

Controls Roll, Pitch, Yaw
Output: Desired torque vector
Prevents overshoot and oscillation

PID Configuration:

csharp

// Position control (aggressive for responsiveness)
PidGains positionGains = new PidGains(
    Kp: 1.0f,   // Proportional gain
    Ki: 0.1f,   // Integral gain
    Kd: 0.5f    // Derivative gain
);

// Attitude control (higher gains for stability)
PidGains attitudeGains = new PidGains(
    Kp: 2.0f,
    Ki: 0.2f,
    Kd: 1.0f
);

// Applied during entity creation via VehicleConfiguration

Control Loop Flow:

1. Calculate position error: target - current
2. PID update → desired thrust vector
3. Calculate target orientation from thrust
4. Calculate attitude error: target orientation - current
5. PID update → desired torque vector
6. Apply thrust and torque to ControlInputs

5. Geographic Coordinate System

Coordinate Conversion:

csharp

// Geographic to Local (ENU: East-North-Up)
Vector3 local = nav.GeoToLocal(
    geoLat: 37.7749,
    geoLon: -122.4194,
    geoAlt: 100.0,
    originLat: 37.7700,
    originLon: -122.4100,
    originAlt: 0.0
);
// Returns: X=East, Y=Up, Z=North in meters

// Local to Geographic
GeoCoordinate geo = nav.LocalToGeo(
    localX: 500.0f,
    localY: 100.0f,
    localZ: 300.0f,
    originLat: 37.7700,
    originLon: -122.4100,
    originAlt: 0.0
);

Distance and Bearing:

csharp

// Haversine distance (great-circle)
double distance = nav.CalculateDistance(
    lat1: 37.7749,
    lon1: -122.4194,
    lat2: 37.8049,
    lon2: -122.3894
);
core.ApiApp().SetTextOutput($"Distance: {distance} meters");

// Initial bearing (compass direction)
double bearing = nav.CalculateBearing(
    lat1: 37.7749,
    lon1: -122.4194,
    lat2: 37.8049,
    lon2: -122.3894
);
core.ApiApp().SetTextOutput($"Bearing: {bearing}° (0=North, 90=East)");

6. Waypoint Management

Setting Waypoints:

csharp

GeoCoordinate[] waypoints = new GeoCoordinate[] {
    new GeoCoordinate(37.7749, -122.4194, 50),
    new GeoCoordinate(37.7849, -122.4094, 100),
    new GeoCoordinate(37.7949, -122.3994, 100),
    new GeoCoordinate(37.8049, -122.3894, 50)
};

nav.SetWaypoints(entityId, waypoints);

Waypoint Following Logic:

Waypoint radius: 5 meters (default)
Switches to next waypoint when within radius
Automatic bearing calculation to next waypoint
Converts geographic to local coordinates for control

Clearing Waypoints:

csharp

nav.ClearWaypoints(entityId);

7. Collision Avoidance

Obstacle Reporting:

csharp

// Report obstacle at local coordinates
nav.ReportObstacle(
    entityId,
    obstacleX: 10.0f,
    obstacleY: 0.0f,
    obstacleZ: 5.0f
);

// Avoidance vector automatically calculated
// Applied as additional thrust to avoid collision

Avoidance Logic:

Collision radius defined in VehicleConfiguration
Calculates repulsive force from obstacle
Decays over time (0.9x per update)
Added to control thrust vector

Clearing Obstacles:

csharp

nav.ClearObstacles(entityId);

8. Advanced Systems

Battery Management:

csharp

nav.UpdateBatteryData(
    entityId,
    voltage: 12.6f,  // Battery voltage
    current: 5.2f    // Current draw in amps
);

// System automatically:
// - Estimates remaining capacity
// - Reduces throttle when low battery
// - Can trigger emergency landing

Weather Compensation:

csharp

nav.UpdateWeatherConditions(
    entityId,
    windX: 2.0f,        // Wind velocity in m/s
    windY: 0.5f,
    windZ: 1.0f,
    airDensity: 1.225f, // Air density in kg/m³
    temperature: 15.0f  // Temperature in °C
);

// Automatically applies wind compensation to thrust

Payload Management:

csharp

nav.ConfigurePayload(
    entityId,
    payloadWeight: 2.5f,  // Payload weight in kg
    centerOfMassX: 0.0f,  // Center of mass offset
    centerOfMassY: -0.1f,
    centerOfMassZ: 0.0f
);

// Deploy payload mid-flight
nav.DeployPayload(entityId);
// System automatically adjusts for weight change

API Reference: ApiNavigation

Entity Management

`CreateNavigationEntity(vehicleType, maxSpeed = 10.0f, maxAcceleration = 5.0f, collisionRadius = 2.0f)`

Creates a new navigation entity for autonomous vehicle control.

Parameters:

vehicleType (VehicleType) - Type of vehicle (Drone, GroundVehicle, WaterCraft, Submarine)
maxSpeed (float, optional) - Maximum speed in m/s (default: 10.0)
maxAcceleration (float, optional) - Maximum acceleration in m/s² (default: 5.0)
collisionRadius (float, optional) - Collision detection radius in meters (default: 2.0)

Returns: int - Navigation entity handle/ID

Example:

csharp

int droneId = nav.CreateNavigationEntity(
    VehicleType.Drone,
    maxSpeed: 15.0f,
    maxAcceleration: 5.0f,
    collisionRadius: 2.5f
);

`UpdateNavigation(deltaTime)`

Updates navigation for all active entities.

Parameters:

deltaTime (float) - Time elapsed since last update in seconds

Behavior:

Clamped to 0.001-0.1 seconds for stability
Updates sensor fusion
Executes navigation mode logic
Updates control systems
Processes waypoints and collision avoidance

Example:

csharp

// Unity FixedUpdate (60 Hz)
void FixedUpdate() {
    nav.UpdateNavigation(Time.fixedDeltaTime);
}

// Manual timing
float deltaTime = 1.0f / 60.0f; // 60 Hz
nav.UpdateNavigation(deltaTime);

`SetNavigationMode(entityId, mode)`

Sets navigation mode for a vehicle.

Parameters:

entityId (int) - Navigation entity ID
mode (NavigationMode) - Navigation mode to use

Navigation Modes:

NavigationMode.Manual - Manual control inputs
NavigationMode.GPS - GPS waypoint following
NavigationMode.SLAM - Vision-based navigation
NavigationMode.Hybrid - GPS + SLAM fusion
NavigationMode.TerrainFollowing - Altitude adjustment
NavigationMode.FormationFlight - Swarm coordination
NavigationMode.Emergency - Fail-safe procedures

Example:

csharp

nav.SetNavigationMode(droneId, NavigationMode.GPS);

`GetNavigationState(entityId)`

Gets current navigation state.

Parameters:

entityId (int) - Navigation entity ID

Returns: NavigationState - Current navigation state

NavigationState Fields:

Position (Vector3) - Local position (X=East, Y=Up, Z=North)
Velocity (Vector3) - Velocity vector in m/s
Acceleration (Vector3) - Acceleration in m/s²
Orientation (Quaternion) - Orientation quaternion
AngularVelocity (Vector3) - Angular velocity in rad/s
GeoPosition (GeoCoordinate) - Geographic position
CompassHeading (double) - Compass heading in degrees
TimestampTicks (long) - High-precision timestamp

Example:

csharp

NavigationState state = nav.GetNavigationState(droneId);
string _state = $"Position: {state.Position}\n" +
                $"Speed: {state.Velocity.Length()} m/s\n" +
                $"Altitude: {state.Position.Y} m\n" +
                $"GPS: {state.GeoPosition.Latitude}, {state.GeoPosition.Longitude}";
core.ApiApp().SetTextOutput(_state);

// Get direction vectors
Vector3 forward = state.Forward();
Vector3 right = state.Right();
Vector3 up = state.Up();

`RemoveEntity(entityId)`

Removes a navigation entity.

Parameters:

entityId (int) - Entity ID to remove

Returns: bool - True if entity was removed successfully

Example:

csharp

bool removed = nav.RemoveEntity(droneId);

`GetActiveEntities()`

Gets all active navigation entity IDs.

Returns: int[] - Array of active entity IDs

Example:

csharp

int[] activeEntities = nav.GetActiveEntities();
core.ApiApp().SetTextOutput($"Active vehicles: {activeEntities.Length}");

string _states = "";
foreach (int entityId in activeEntities) {
    NavigationState state = nav.GetNavigationState(entityId);
    _states += $"Entity {entityId}: {state.Position}\n"
}
core.ApiApp().SetTextOutput(_states);

`ResetNavigationSystem()`

Resets navigation system (clears all entities and origin).

Example:

csharp

nav.ResetNavigationSystem();

Control Inputs

`SetManualControl(entityId, thrustX, thrustY, thrustZ, throttle)`

Sets manual control inputs for a vehicle.

Parameters:

entityId (int) - Navigation entity ID
thrustX (float) - Thrust vector X component (-1 to 1)
thrustY (float) - Thrust vector Y component (-1 to 1)
thrustZ (float) - Thrust vector Z component (-1 to 1)
throttle (float) - Throttle setting (0 to 1)

Behavior:

Automatically switches to Manual mode
Inputs clamped to valid ranges
Updates command timestamp

Example:

csharp

// Joystick input
float joyX = Input.GetAxis("Horizontal");   // -1 to 1
float joyY = Input.GetAxis("Vertical");     // -1 to 1
float joyThrottle = Input.GetAxis("Throttle"); // 0 to 1

nav.SetManualControl(droneId, joyX, 0.0f, joyY, joyThrottle);

`EmergencyStop(entityId)`

Triggers emergency stop for a vehicle.

Parameters:

entityId (int) - Navigation entity ID

Behavior:

Immediately zeros all thrust and torque
Sets emergency stop flag
Switches to Manual mode

Example:

csharp

// Emergency stop button
if (Input.GetKeyDown(KeyCode.Space)) {
    nav.EmergencyStop(droneId);
    core.ApiApp().SetTextOutput("EMERGENCY STOP ACTIVATED");
}

Waypoint Management

`SetWaypoints(entityId, waypoints)`

Sets waypoints for autonomous navigation.

Parameters:

entityId (int) - Navigation entity ID
waypoints (GeoCoordinate[]) - Array of geographic coordinates

Example:

csharp

GeoCoordinate[] waypoints = new GeoCoordinate[] {
    new GeoCoordinate(37.7749, -122.4194, 50),
    new GeoCoordinate(37.7849, -122.4094, 100),
    new GeoCoordinate(37.7949, -122.3994, 100)
};

nav.SetWaypoints(droneId, waypoints);

`ClearWaypoints(entityId)`

Clears all waypoints for a vehicle.

Parameters:

entityId (int) - Navigation entity ID

Example:

csharp

nav.ClearWaypoints(droneId);

`SetTargetPosition(entityId, latitude, longitude, altitude)`

Sets target position for navigation.

Parameters:

entityId (int) - Navigation entity ID
latitude (double) - Target latitude in degrees
longitude (double) - Target longitude in degrees
altitude (double) - Target altitude in meters

Example:

csharp

// Fly to specific location
nav.SetTargetPosition(droneId, 37.7749, -122.4194, 100.0);

Sensor Integration

`UpdateGpsData(entityId, latitude, longitude, altitude, accuracy, velocityX, velocityY, velocityZ)`

Updates GPS sensor data.

Parameters:

entityId (int) - Navigation entity ID
latitude (double) - GPS latitude in degrees
longitude (double) - GPS longitude in degrees
altitude (double) - GPS altitude in meters
accuracy (float) - GPS accuracy in meters
velocityX (float) - GPS velocity X component in m/s
velocityY (float) - GPS velocity Y component in m/s
velocityZ (float) - GPS velocity Z component in m/s

Behavior:

Sets global origin on first GPS reading
Marks GPS as valid if accuracy < 10m
Updates sensor timestamp

Example:

csharp

// GPS update from external sensor
nav.UpdateGpsData(
    droneId,
    latitude: gpsModule.Latitude,
    longitude: gpsModule.Longitude,
    altitude: gpsModule.Altitude,
    accuracy: gpsModule.Accuracy,
    velocityX: gpsModule.VelocityNorth,
    velocityY: gpsModule.VelocityUp,
    velocityZ: gpsModule.VelocityEast
);

`UpdateImuData(entityId, accelX, accelY, accelZ, gyroX, gyroY, gyroZ)`

Updates IMU sensor data.

Parameters:

entityId (int) - Navigation entity ID
accelX (float) - Accelerometer X in m/s²
accelY (float) - Accelerometer Y in m/s²
accelZ (float) - Accelerometer Z in m/s²
gyroX (float) - Gyroscope X in rad/s
gyroY (float) - Gyroscope Y in rad/s
gyroZ (float) - Gyroscope Z in rad/s

Example:

csharp

nav.UpdateImuData(
    droneId,
    accelX: imu.AccelX,
    accelY: imu.AccelY,
    accelZ: imu.AccelZ,
    gyroX: imu.GyroX,
    gyroY: imu.GyroY,
    gyroZ: imu.GyroZ
);

`UpdateCompassData(entityId, heading)`

Updates compass heading.

Parameters:

entityId (int) - Navigation entity ID
heading (double) - Compass heading in degrees (0=North, 90=East)

Example:

csharp

nav.UpdateCompassData(droneId, compass.Heading);

Collision Avoidance

`ReportObstacle(entityId, obstacleX, obstacleY, obstacleZ)`

Reports obstacle for collision avoidance.

Parameters:

entityId (int) - Navigation entity ID
obstacleX (float) - Obstacle X position in local coordinates
obstacleY (float) - Obstacle Y position in local coordinates
obstacleZ (float) - Obstacle Z position in local coordinates

Behavior:

Calculates repulsive avoidance vector
Applied as additional thrust
Decays over time

Example:

csharp

// Report obstacle detected by LiDAR
if (lidar.ObstacleDetected) {
    nav.ReportObstacle(
        droneId,
        lidar.ObstaclePosition.x,
        lidar.ObstaclePosition.y,
        lidar.ObstaclePosition.z
    );
}

`ClearObstacles(entityId)`

Clears all reported obstacles.

Parameters:

entityId (int) - Navigation entity ID

Example:

csharp

nav.ClearObstacles(droneId);

`EnableTerrainFollowing(entityId, desiredAltitude, terrainClearance)`

Enables terrain following navigation mode.

Parameters:

entityId (int) - Navigation entity ID
desiredAltitude (float) - Desired altitude above terrain in meters
terrainClearance (float) - Minimum clearance above terrain in meters

Example:

csharp

nav.EnableTerrainFollowing(droneId, desiredAltitude: 50.0f, terrainClearance: 20.0f);

`EnableFormationFlight(entityId, formationId, positionInFormation, offsetX, offsetY, offsetZ)`

Enables formation flight mode.

Parameters:

entityId (int) - Navigation entity ID
formationId (int) - Formation identifier
positionInFormation (int) - Position in formation (0 = leader)
offsetX (float) - Relative X offset from leader
offsetY (float) - Relative Y offset from leader
offsetZ (float) - Relative Z offset from leader

Example:

csharp

// V-formation, right wing position
nav.EnableFormationFlight(
    droneId,
    formationId: 1,
    positionInFormation: 2,
    offsetX: 10.0f,   // 10m to the right
    offsetY: 0.0f,
    offsetZ: -8.0f    // 8m behind
);

`TriggerEmergency(entityId)`

Triggers emergency mode.

Parameters:

entityId (int) - Navigation entity ID

Behavior:

Switches to Emergency navigation mode
Executes fail-safe procedures (hover or controlled descent)

Example:

csharp

if (criticalFailure) {
    nav.TriggerEmergency(droneId);
}

Vehicle Systems

`UpdateBatteryData(entityId, voltage, current)`

Updates battery sensor data.

Parameters:

entityId (int) - Navigation entity ID
voltage (float) - Battery voltage
current (float) - Battery current draw

Example:

csharp

nav.UpdateBatteryData(droneId, battery.Voltage, battery.Current);

`UpdateWeatherConditions(entityId, windX, windY, windZ, airDensity, temperature)`

Updates weather conditions.

Parameters:

entityId (int) - Navigation entity ID
windX (float) - Wind velocity X component
windY (float) - Wind velocity Y component
windZ (float) - Wind velocity Z component
airDensity (float) - Air density
temperature (float) - Temperature in Celsius

Example:

csharp

nav.UpdateWeatherConditions(
    droneId,
    windX: 2.5f,
    windY: 0.5f,
    windZ: 1.0f,
    airDensity: 1.225f,
    temperature: 15.0f
);

`ConfigurePayload(entityId, payloadWeight, centerOfMassX, centerOfMassY, centerOfMassZ)`

Configures payload for the vehicle.

Parameters:

entityId (int) - Navigation entity ID
payloadWeight (float) - Payload weight in kg
centerOfMassX (float) - Center of mass X offset
centerOfMassY (float) - Center of mass Y offset
centerOfMassZ (float) - Center of mass Z offset

Example:

csharp

nav.ConfigurePayload(
    droneId,
    payloadWeight: 2.5f,
    centerOfMassX: 0.0f,
    centerOfMassY: -0.1f,  // Payload hangs below
    centerOfMassZ: 0.0f
);

`DeployPayload(entityId)`

Deploys payload.

Parameters:

entityId (int) - Navigation entity ID

Behavior:

Marks payload as deployed
System automatically adjusts for weight change

Example:

csharp

// Deploy package at delivery location
if (atDeliveryLocation) {
    nav.DeployPayload(droneId);
    core.ApiApp().SetTextOutput("Package deployed");
}

`UpdateTerrainData(entityId, terrainHeight, normalX, normalY, normalZ)`

Updates terrain information for terrain following.

Parameters:

entityId (int) - Navigation entity ID
terrainHeight (float) - Terrain height at current position
normalX (float) - Terrain surface normal X
normalY (float) - Terrain surface normal Y
normalZ (float) - Terrain surface normal Z

Example:

csharp

// From LiDAR/altimeter
nav.UpdateTerrainData(
    droneId,
    terrainHeight: lidar.GroundHeight,
    normalX: terrainNormal.x,
    normalY: terrainNormal.y,
    normalZ: terrainNormal.z
);

Coordinate Conversion

`CalculateDistance(lat1, lon1, lat2, lon2)`

Calculates distance between two geographic coordinates using Haversine formula.

Parameters:

lat1 (double) - Latitude of first point in degrees
lon1 (double) - Longitude of first point in degrees
lat2 (double) - Latitude of second point in degrees
lon2 (double) - Longitude of second point in degrees

Returns: double - Distance in meters

Example:

csharp

double distance = nav.CalculateDistance(37.7749, -122.4194, 37.8049, -122.3894);
core.ApiApp().SetTextOutput($"Distance: {distance:F2} meters");

`CalculateBearing(lat1, lon1, lat2, lon2)`

Calculates bearing from one geographic coordinate to another.

Parameters:

lat1 (double) - Latitude of starting point in degrees
lon1 (double) - Longitude of starting point in degrees
lat2 (double) - Latitude of target point in degrees
lon2 (double) - Longitude of target point in degrees

Returns: double - Bearing in degrees (0 = North, 90 = East)

Example:

csharp

double bearing = nav.CalculateBearing(37.7749, -122.4194, 37.8049, -122.3894);
core.ApiApp().SetTextOutput($"Fly heading: {bearing:F1}°");

`GeoToLocal(geoLat, geoLon, geoAlt, originLat, originLon, originAlt)`

Converts geographic coordinates to local Cartesian coordinates.

Parameters:

geoLat (double) - Geographic latitude in degrees
geoLon (double) - Geographic longitude in degrees
geoAlt (double) - Geographic altitude in meters
originLat (double) - Origin latitude in degrees
originLon (double) - Origin longitude in degrees
originAlt (double) - Origin altitude in meters

Returns: Vector3 - Local position (X=East, Y=Up, Z=North)

Example:

csharp

Vector3 local = nav.GeoToLocal(
    geoLat: 37.7749,
    geoLon: -122.4194,
    geoAlt: 100.0,
    originLat: 37.7700,
    originLon: -122.4100,
    originAlt: 0.0
);
core.ApiApp().SetTextOutput($"Local position: {local}");

`LocalToGeo(localX, localY, localZ, originLat, originLon, originAlt)`

Converts local Cartesian coordinates to geographic coordinates.

Parameters:

localX (float) - Local X coordinate (East) in meters
localY (float) - Local Y coordinate (Up) in meters
localZ (float) - Local Z coordinate (North) in meters
originLat (double) - Origin latitude in degrees
originLon (double) - Origin longitude in degrees
originAlt (double) - Origin altitude in meters

Returns: GeoCoordinate - Geographic coordinate

Example:

csharp

GeoCoordinate geo = nav.LocalToGeo(
    localX: 500.0f,
    localY: 100.0f,
    localZ: 300.0f,
    originLat: 37.7700,
    originLon: -122.4100,
    originAlt: 0.0
);
core.ApiApp().SetTextOutput($"GPS: {geo.Latitude}, {geo.Longitude}, Alt: {geo.Altitude}m");

Utility Functions

`WrapAngle(angle)`

Wraps angle to -180 to 180 degree range.

Parameters:

angle (float) - Input angle in degrees

Returns: float - Wrapped angle in degrees

Example:

csharp

float wrapped = nav.WrapAngle(370.0f);  // Returns 10.0
float wrapped2 = nav.WrapAngle(-190.0f); // Returns 170.0

`HeadingToQuaternion(headingDegrees)`

Converts heading angle to quaternion rotation.

Parameters:

headingDegrees (double) - Heading angle in degrees

Returns: Quaternion - Quaternion representing the rotation

Example:

csharp

Quaternion rotation = nav.HeadingToQuaternion(45.0);
// Rotation for 45° heading (northeast)

`IsNavigationAvailable()`

Checks if navigation system is available.

Returns: bool - True if navigation system is operational

Example:

csharp

if (nav.IsNavigationAvailable()) {
    core.ApiApp().SetTextOutput("Navigation system online");
}

`GetNavigationStatus()`

Gets navigation system status.

Returns: string - Status string describing navigation system state

Example:

csharp

string status = nav.GetNavigationStatus();
core.ApiApp().SetTextOutput(status);
// "Navigation system operational - 3 active entities, Global origin: set, Total entities: 5"

`GetEntityDiagnostics(entityId)`

Gets navigation diagnostics for an entity.

Parameters:

entityId (int) - Entity ID

Returns: string - Diagnostic information string

Example:

csharp

string diagnostics = nav.GetEntityDiagnostics(droneId);
core.ApiApp().SetTextOutput(diagnostics);
// "Entity 1 - Mode: GPS, Active: True
//  Position: (10.00, 50.00, 20.00)
//  Velocity: (5.00, 0.50, 2.00)
//  Target: (100.00, 100.00, 50.00)
//  Sensors: GPS=True, IMU=True, Compass=True"

Advanced Patterns

csharp

void UpdateNavigationSensors(int entityId) {
    // GPS (outdoor)
    if (gpsModule.IsValid) {
        nav.UpdateGpsData(
            entityId,
            gpsModule.Latitude,
            gpsModule.Longitude,
            gpsModule.Altitude,
            gpsModule.Accuracy,
            gpsModule.VelocityNorth,
            gpsModule.VelocityUp,
            gpsModule.VelocityEast
        );
    }
    
    // IMU (always available)
    nav.UpdateImuData(
        entityId,
        imu.AccelX, imu.AccelY, imu.AccelZ,
        imu.GyroX, imu.GyroY, imu.GyroZ
    );
    
    // Compass (always available)
    nav.UpdateCompassData(entityId, compass.Heading);
    
    // SLAM (indoor or GPS-denied)
    if (slamModule.IsValid) {
        nav.UpdateSlamData(
            entityId,
            slamModule.Position,
            slamModule.Orientation,
            slamModule.Confidence
        );
    }
    
    // Hybrid mode automatically fuses all sensors
    nav.SetNavigationMode(entityId, NavigationMode.Hybrid);
}

Pattern 2: Precision Landing with Terrain Awareness

csharp

void PrecisionLanding(int entityId, GeoCoordinate landingZone) {
    // Approach phase
    nav.SetTargetPosition(
        entityId,
        landingZone.Latitude,
        landingZone.Longitude,
        50.0 // Approach altitude
    );
    
    // Enable terrain following for descent
    nav.EnableTerrainFollowing(entityId, desiredAltitude: 10.0f, terrainClearance: 5.0f);
    
    // Monitor approach
    NavigationState state = nav.GetNavigationState(entityId);
    double distanceToTarget = nav.CalculateDistance(
        state.GeoPosition.Latitude,
        state.GeoPosition.Longitude,
        landingZone.Latitude,
        landingZone.Longitude
    );
    
    // Final descent when close
    if (distanceToTarget < 2.0) {
        nav.SetTargetPosition(
            entityId,
            landingZone.Latitude,
            landingZone.Longitude,
            0.0 // Ground level
        );
    }
}

Pattern 3: Swarm Coordination with Formation Control

csharp

class SwarmController {
    private int leaderId;
    private List<int> followerIds = new List<int>();
    
    void InitializeSwarm(int swarmSize) {
        // Create leader
        leaderId = nav.CreateNavigationEntity(VehicleType.Drone, maxSpeed: 20.0f);
        nav.SetNavigationMode(leaderId, NavigationMode.GPS);
        
        // Create followers in formation
        float spacing = 10.0f;
        for (int i = 0; i < swarmSize - 1; i++) {
            int followerId = nav.CreateNavigationEntity(VehicleType.Drone, maxSpeed: 20.0f);
            
            // V-formation offsets
            float offsetX = (i % 2 == 0) ? -spacing : spacing;
            float offsetZ = -(i / 2 + 1) * spacing * 0.8f;
            
            nav.EnableFormationFlight(
                followerId,
                formationId: 1,
                positionInFormation: i + 1,
                offsetX: offsetX,
                offsetY: 0.0f,
                offsetZ: offsetZ
            );
            
            followerIds.Add(followerId);
        }
    }
    
    void NavigateSwarm(GeoCoordinate destination) {
        // Leader navigates, followers maintain formation
        nav.SetTargetPosition(
            leaderId,
            destination.Latitude,
            destination.Longitude,
            destination.Altitude
        );
    }
}

Pattern 4: Emergency Procedures with Battery Monitoring

csharp

void MonitorVehicleHealth(int entityId) {
    // Update battery
    nav.UpdateBatteryData(entityId, battery.Voltage, battery.Current);
    
    // Check critical thresholds
    if (battery.Voltage < 11.0f) {
        core.ApiApp().SetTextOutput("CRITICAL: Battery voltage low, initiating emergency landing");
        nav.TriggerEmergency(entityId);
        
        // Find nearest safe landing zone
        GeoCoordinate nearestLZ = FindNearestLandingZone();
        nav.SetTargetPosition(entityId, nearestLZ.Latitude, nearestLZ.Longitude, 0.0);
    }
    else if (battery.Voltage < 11.5f) {
        core.ApiApp().SetTextOutput("WARNING: Battery voltage low, reducing performance");
        // System automatically reduces throttle in control loop
    }
    
    // Monitor GPS health
    NavigationState state = nav.GetNavigationState(entityId);
    if (!state.Sensors.GpsValid && nav.GetNavigationMode(entityId) == NavigationMode.GPS) {
        core.ApiApp().SetTextOutput("WARNING: GPS lost, switching to SLAM");
        nav.SetNavigationMode(entityId, NavigationMode.SLAM);
    }
}

Pattern 5: Adaptive Control Based on Environment

csharp

void AdaptiveNavigationControl(int entityId) {
    NavigationState state = nav.GetNavigationState(entityId);
    
    // Detect environment and switch modes
    if (state.Sensors.GpsValid && state.Sensors.GpsAccuracy < 5.0f) {
        // Good GPS, use GPS navigation
        if (nav.GetNavigationMode(entityId) != NavigationMode.GPS) {
            nav.SetNavigationMode(entityId, NavigationMode.GPS);
            core.ApiApp().SetTextOutput("Switched to GPS navigation (good signal)");
        }
    }
    else if (state.Sensors.SlamValid && state.Sensors.SlamConfidence > 0.8f) {
        // GPS poor, SLAM strong, use SLAM
        if (nav.GetNavigationMode(entityId) != NavigationMode.SLAM) {
            nav.SetNavigationMode(entityId, NavigationMode.SLAM);
            core.ApiApp().SetTextOutput("Switched to SLAM navigation (GPS weak)");
        }
    }
    else if (state.Sensors.GpsValid && state.Sensors.SlamValid) {
        // Both available, use hybrid fusion
        if (nav.GetNavigationMode(entityId) != NavigationMode.Hybrid) {
            nav.SetNavigationMode(entityId, NavigationMode.Hybrid);
            core.ApiApp().SetTextOutput("Switched to Hybrid navigation (multi-sensor fusion)");
        }
    }
    
    // Update weather compensation
    if (windSensor.Available) {
        nav.UpdateWeatherConditions(
            entityId,
            windSensor.WindX,
            windSensor.WindY,
            windSensor.WindZ,
            airDensitySensor.Density,
            temperatureSensor.Temperature
        );
    }
}

Best Practices

csharp

// Unity: Use FixedUpdate for consistent timing
void FixedUpdate() {
    nav.UpdateNavigation(Time.fixedDeltaTime);
}

// Non-Unity: Manual timing loop
float targetDeltaTime = 1.0f / 60.0f; // 60 Hz
nav.UpdateNavigation(targetDeltaTime);

2. Validate Sensor Data Before Updating

csharp

void UpdateSensors(int entityId) {
    // Only update GPS if valid
    if (gpsModule.IsValid && gpsModule.Accuracy < 10.0f) {
        nav.UpdateGpsData(entityId, /* ... */);
    }
    
    // Always update IMU (typically always available)
    nav.UpdateImuData(entityId, /* ... */);
    
    // Update SLAM if tracking is good
    if (slamModule.IsTracking && slamModule.Confidence > 0.7f) {
        nav.UpdateSlamData(entityId, /* ... */);
    }
}

3. Handle Mode Transitions Gracefully

csharp

void SafeModeSwitch(int entityId, NavigationMode newMode) {
    NavigationMode currentMode = GetCurrentMode(entityId);
    
    if (currentMode == newMode) return;
    
    // Clear waypoints when switching to manual
    if (newMode == NavigationMode.Manual) {
        nav.ClearWaypoints(entityId);
    }
    
    // Set waypoints when switching to GPS
    if (newMode == NavigationMode.GPS && currentMode == NavigationMode.Manual) {
        GeoCoordinate[] waypoints = GetMissionWaypoints();
        nav.SetWaypoints(entityId, waypoints);
    }
    
    nav.SetNavigationMode(entityId, newMode);
    core.ApiApp().SetTextOutput($"Mode switched: {currentMode} → {newMode}");
}

csharp

void MonitorNavigationHealth(int entityId) {
    NavigationState state = nav.GetNavigationState(entityId);
    
    // Check velocity limits
    float speed = state.Velocity.Length();
    if (speed > vehicleMaxSpeed * 1.1f) {
        core.ApiApp().SetTextOutput($"WARNING: Overspeed detected: {speed:F1} m/s");
    }
    
    // Check altitude
    if (state.Position.Y < minSafeAltitude) {
        core.ApiApp().SetTextOutput($"WARNING: Low altitude: {state.Position.Y:F1} m");
    }
    
    // Check sensor health
    if (!state.Sensors.GpsValid && !state.Sensors.SlamValid) {
        core.ApiApp().SetTextOutput("CRITICAL: No positioning sensors available");
        nav.TriggerEmergency(entityId);
    }
}

5. Use Proper Coordinate System Conversions

csharp

// Always set origin before converting coordinates
GeoCoordinate globalOrigin = new GeoCoordinate(37.7700, -122.4100, 0.0);

// Convert target from GPS to local for visualization
Vector3 targetLocal = nav.GeoToLocal(
    targetGPS.Latitude,
    targetGPS.Longitude,
    targetGPS.Altitude,
    globalOrigin.Latitude,
    globalOrigin.Longitude,
    globalOrigin.Altitude
);

// Convert local position back to GPS for logging
GeoCoordinate currentGPS = nav.LocalToGeo(
    state.Position.X,
    state.Position.Y,
    state.Position.Z,
    globalOrigin.Latitude,
    globalOrigin.Longitude,
    globalOrigin.Altitude
);

6. Implement Robust Error Recovery

csharp

void ErrorRecovery(int entityId, Exception error) {
    core.ApiApp().SetTextOutput($"Navigation error: {error.Message}");
    
    // Attempt recovery
    try {
        // Stop current motion
        nav.EmergencyStop(entityId);
        
        // Clear potentially corrupt waypoints
        nav.ClearWaypoints(entityId);
        nav.ClearObstacles(entityId);
        
        // Reset to manual mode
        nav.SetNavigationMode(entityId, NavigationMode.Manual);
        
        // Hover in place
        nav.SetManualControl(entityId, 0.0f, 0.0f, 0.0f, 0.5f);
        
        core.ApiApp().SetTextOutput("Recovery successful, manual control enabled");
    }
    catch (Exception recoveryError) {
        core.ApiApp().SetErrorOutput($"CRITICAL: Recovery failed: {recoveryError.Message}");
        // Last resort: trigger emergency procedures
        nav.TriggerEmergency(entityId);
    }
}

Performance Characteristics

Update Frequency

Recommended: 60 Hz (16.7ms) for drones
Minimum: 30 Hz (33ms) for ground vehicles
Maximum: 200 Hz (5ms) for high-performance systems

Latency

Sensor Fusion: <1ms
PID Control: <1ms
Waypoint Following: <2ms
Total Update: <5ms (typical)

Memory Footprint

Per Entity: ~2KB (struct-based)
No GC Allocations: Zero-allocation design
Scalability: 100+ entities on modern hardware

Remarks

SILVIA's Navigation API delivers production-grade autonomous vehicle guidance with multi-modal sensor fusion, advanced control systems, and zero-allocation performance. From delivery drones to tactical UAV swarms to autonomous rovers, Navigation provides the precision, reliability, and safety required for real-world autonomous systems.

Key Advantages:

Multi-Modal Fusion - GPS, IMU, SLAM, Compass integration
Advanced Modes - Terrain following, formation flight, hybrid navigation
PID Control - Precise position and attitude control
Zero-Allocation - Struct-based components, no GC pressure
Safety First - Emergency procedures, battery monitoring, fail-safes
Platform Agnostic - Works with any sensor hardware via simple integration

SILVIA is a registered Trademark of Cognitive Code Corp.

SILVIA Core ApiNavigation Reference ​

Autonomous Vehicle Guidance with Multi-Modal Sensor Fusion ​

Architectural Philosophy: Composition Over Hierarchy ​

Vehicle Types & Capabilities ​

Modern Use Cases ​

1. Autonomous Delivery Drone with GPS Waypoints ​

2. UAV Swarm Formation Flight ​

3. Terrain-Following Drone for Mapping ​

4. Autonomous Ground Vehicle with Hybrid Navigation ​

5. Emergency Landing with Battery Management ​

6. Manual Control with Override ​

Core Concepts ​

1. Navigation Entity System ​

2. Navigation Modes ​

3. Multi-Modal Sensor Fusion ​

4. PID Control System ​

5. Geographic Coordinate System ​

6. Waypoint Management ​

7. Collision Avoidance ​

8. Advanced Systems ​

API Reference: ApiNavigation ​

Entity Management ​

CreateNavigationEntity(vehicleType, maxSpeed = 10.0f, maxAcceleration = 5.0f, collisionRadius = 2.0f) ​

UpdateNavigation(deltaTime) ​

SetNavigationMode(entityId, mode) ​

GetNavigationState(entityId) ​

RemoveEntity(entityId) ​

GetActiveEntities() ​

ResetNavigationSystem() ​

Control Inputs ​

SetManualControl(entityId, thrustX, thrustY, thrustZ, throttle) ​

EmergencyStop(entityId) ​

Waypoint Management ​

SetWaypoints(entityId, waypoints) ​

ClearWaypoints(entityId) ​

SetTargetPosition(entityId, latitude, longitude, altitude) ​

Sensor Integration ​

UpdateGpsData(entityId, latitude, longitude, altitude, accuracy, velocityX, velocityY, velocityZ) ​

UpdateImuData(entityId, accelX, accelY, accelZ, gyroX, gyroY, gyroZ) ​

UpdateCompassData(entityId, heading) ​

Collision Avoidance ​

ReportObstacle(entityId, obstacleX, obstacleY, obstacleZ) ​

ClearObstacles(entityId) ​

Advanced Navigation Modes ​

EnableTerrainFollowing(entityId, desiredAltitude, terrainClearance) ​

EnableFormationFlight(entityId, formationId, positionInFormation, offsetX, offsetY, offsetZ) ​

TriggerEmergency(entityId) ​

Vehicle Systems ​

UpdateBatteryData(entityId, voltage, current) ​

UpdateWeatherConditions(entityId, windX, windY, windZ, airDensity, temperature) ​

ConfigurePayload(entityId, payloadWeight, centerOfMassX, centerOfMassY, centerOfMassZ) ​

DeployPayload(entityId) ​

UpdateTerrainData(entityId, terrainHeight, normalX, normalY, normalZ) ​

Coordinate Conversion ​

CalculateDistance(lat1, lon1, lat2, lon2) ​

CalculateBearing(lat1, lon1, lat2, lon2) ​

GeoToLocal(geoLat, geoLon, geoAlt, originLat, originLon, originAlt) ​

LocalToGeo(localX, localY, localZ, originLat, originLon, originAlt) ​

Utility Functions ​

WrapAngle(angle) ​

HeadingToQuaternion(headingDegrees) ​

IsNavigationAvailable() ​

GetNavigationStatus() ​

GetEntityDiagnostics(entityId) ​

Advanced Patterns ​

Pattern 1: Multi-Sensor Fusion for Robust Navigation ​

Pattern 2: Precision Landing with Terrain Awareness ​

Pattern 3: Swarm Coordination with Formation Control ​

Pattern 4: Emergency Procedures with Battery Monitoring ​

Pattern 5: Adaptive Control Based on Environment ​

Best Practices ​

1. Always Update Navigation Regularly ​

2. Validate Sensor Data Before Updating ​

3. Handle Mode Transitions Gracefully ​

4. Monitor Navigation State Continuously ​

5. Use Proper Coordinate System Conversions ​

6. Implement Robust Error Recovery ​

Performance Characteristics ​

Update Frequency ​

Latency ​

SILVIA Core ApiNavigation Reference

Autonomous Vehicle Guidance with Multi-Modal Sensor Fusion

Architectural Philosophy: Composition Over Hierarchy

Vehicle Types & Capabilities

Modern Use Cases

1. Autonomous Delivery Drone with GPS Waypoints

2. UAV Swarm Formation Flight

3. Terrain-Following Drone for Mapping

4. Autonomous Ground Vehicle with Hybrid Navigation

5. Emergency Landing with Battery Management

6. Manual Control with Override

Core Concepts

1. Navigation Entity System

2. Navigation Modes

3. Multi-Modal Sensor Fusion

4. PID Control System

5. Geographic Coordinate System

6. Waypoint Management

7. Collision Avoidance

8. Advanced Systems

API Reference: ApiNavigation

Entity Management

`CreateNavigationEntity(vehicleType, maxSpeed = 10.0f, maxAcceleration = 5.0f, collisionRadius = 2.0f)`

`UpdateNavigation(deltaTime)`

`SetNavigationMode(entityId, mode)`

`GetNavigationState(entityId)`

`RemoveEntity(entityId)`

`GetActiveEntities()`

`ResetNavigationSystem()`

Control Inputs

`SetManualControl(entityId, thrustX, thrustY, thrustZ, throttle)`

`EmergencyStop(entityId)`

Waypoint Management

`SetWaypoints(entityId, waypoints)`

`ClearWaypoints(entityId)`

`SetTargetPosition(entityId, latitude, longitude, altitude)`

Sensor Integration

`UpdateGpsData(entityId, latitude, longitude, altitude, accuracy, velocityX, velocityY, velocityZ)`

`UpdateImuData(entityId, accelX, accelY, accelZ, gyroX, gyroY, gyroZ)`

`UpdateCompassData(entityId, heading)`

Collision Avoidance

`ReportObstacle(entityId, obstacleX, obstacleY, obstacleZ)`

`ClearObstacles(entityId)`

Advanced Navigation Modes

`EnableTerrainFollowing(entityId, desiredAltitude, terrainClearance)`

`EnableFormationFlight(entityId, formationId, positionInFormation, offsetX, offsetY, offsetZ)`

`TriggerEmergency(entityId)`

Vehicle Systems

`UpdateBatteryData(entityId, voltage, current)`

`UpdateWeatherConditions(entityId, windX, windY, windZ, airDensity, temperature)`

`ConfigurePayload(entityId, payloadWeight, centerOfMassX, centerOfMassY, centerOfMassZ)`

`DeployPayload(entityId)`

`UpdateTerrainData(entityId, terrainHeight, normalX, normalY, normalZ)`

Coordinate Conversion

`CalculateDistance(lat1, lon1, lat2, lon2)`

`CalculateBearing(lat1, lon1, lat2, lon2)`

`GeoToLocal(geoLat, geoLon, geoAlt, originLat, originLon, originAlt)`

`LocalToGeo(localX, localY, localZ, originLat, originLon, originAlt)`

Utility Functions

`WrapAngle(angle)`

`HeadingToQuaternion(headingDegrees)`

`IsNavigationAvailable()`

`GetNavigationStatus()`

`GetEntityDiagnostics(entityId)`

Advanced Patterns

Pattern 1: Multi-Sensor Fusion for Robust Navigation

Pattern 2: Precision Landing with Terrain Awareness

Pattern 3: Swarm Coordination with Formation Control

Pattern 4: Emergency Procedures with Battery Monitoring

Pattern 5: Adaptive Control Based on Environment

Best Practices

1. Always Update Navigation Regularly

2. Validate Sensor Data Before Updating

3. Handle Mode Transitions Gracefully

4. Monitor Navigation State Continuously

5. Use Proper Coordinate System Conversions

6. Implement Robust Error Recovery

Performance Characteristics

Update Frequency

Latency