RTLS Rocketry Project

Return-To-Launch-Site Trajectory Control System

MATLAB ESP32 Kalman Filter Monte Carlo GNC

Project Overview

As the GNC (Guidance, Navigation, and Control) Lead for the UCF Senior Design RTLS Rocketry Team Purple, I spearheaded the development of an innovative Return-To-Launch-Site trajectory control system. This project demonstrates the intersection of mechanical engineering principles and advanced software development.

Key Achievements

Trajectory Control Algorithm

Developed an adaptive PD control system in MATLAB for real-time course correction under variable wind conditions.

Avionics Integration

Led full-system integration of multiple sensors including GPS, IMU, barometer, magnetometer, and radio, with sophisticated calibration for environmental factors.

Simulation & Analysis

Implemented Monte Carlo analysis with 1000+ randomized trials, achieving landing accuracy within 800 ft of target.

Technical Implementation

System Architecture

  • Dual-core embedded system architecture on ESP32
  • Real-time sensor fusion using Kalman filtering
  • Hardware-in-the-loop (HIL) testing framework
  • Telemetry radio integration and SD data logging

Control System Design

  • Adaptive PD control algorithm
  • Wind compensation system
  • Real-time trajectory optimization
  • Fail-safe mechanisms and error handling

Detailed Technical Specifications

Hardware Components

  • Microcontroller:
    • ESP32-WROOM-32D
    • Dual-core processor up to 240MHz
    • 520KB SRAM, 4MB Flash
  • Sensors:
    • BNO055 9-DOF IMU
    • NEO-M8N GPS Module
    • BMP388 Barometric Pressure Sensor
    • RFM95W LoRa Radio Module

Software Architecture

  • Real-time OS:
    • FreeRTOS Task Management
    • Dual-core Task Distribution
    • Interrupt-driven Sensor Handling
  • Communication Protocols:
    • I2C for Sensor Integration
    • SPI for Radio Communication
    • UART for GPS Data

Control System Implementation

Guidance Algorithm

The guidance system employs a sophisticated PD control algorithm with adaptive gains based on flight conditions:

Position Control
  • Proportional Gain (Kp): 0.8 - 2.5 (adaptive)
  • Derivative Gain (Kd): 0.3 - 1.2 (adaptive)
  • Update Rate: 50Hz
Wind Compensation
  • Real-time wind estimation using Kalman filtering
  • Dynamic trajectory adjustment
  • Maximum wind speed tolerance: 15 mph

Navigation System

Sensor Fusion
  • Extended Kalman Filter implementation
  • GPS position accuracy: ±2.5m
  • Attitude estimation rate: 100Hz
  • Barometric altitude resolution: ±0.5m
State Estimation
  • 13-state vector tracking
  • Position and velocity estimation
  • Quaternion-based attitude representation
  • Bias and scale factor compensation

Performance Analysis

Monte Carlo Simulation Results

  • Number of trials: 1,000+
  • Success rate: 92%
  • Average landing accuracy: 450ft
  • Maximum deviation: 800ft

System Specifications

  • Control loop frequency: 50Hz
  • Sensor fusion update rate: 100Hz
  • Telemetry transmission rate: 10Hz
  • Data logging rate: 20Hz

Key Performance Metrics

Metric Target Achieved
Landing Accuracy < 1000 ft 800 ft
Control Response Time < 50 ms 20 ms
Wind Tolerance 12 mph 15 mph
Battery Life 2 hours 2.5 hours

Testing and Validation

Hardware-in-the-Loop Testing
  • Custom MATLAB simulation environment
  • Real-time sensor data injection
  • Performance validation under various conditions
Field Testing
  • Multiple test flights conducted
  • Data collection and analysis
  • System refinement based on real-world performance
Safety Features
  • Redundant sensor systems
  • Fail-safe recovery modes
  • Emergency abort capabilities

Hardware-in-the-Loop Demonstration

Watch our HIL testing system in action, demonstrating real-time sensor data processing and control system response:

About this Demonstration

This video showcases our Hardware-in-the-Loop testing environment, where we:

  • Simulate flight conditions and sensor inputs
  • Validate control system response in real-time
  • Test edge cases and failure scenarios
  • Verify system performance metrics

Project Documentation

Access the comprehensive technical documentation for the RTLS project, including detailed system architecture, validation strategies, performance analysis, and complete implementation details:

This comprehensive document contains all technical details, implementation strategies, and project outcomes.

Results & Impact

  • Achieved consistent landing accuracy within 800 ft across 1000 simulated trials
  • Successfully implemented real-time wind compensation
  • Developed reusable GNC framework for future projects
  • Created comprehensive documentation for knowledge transfer