BPS.space's High-Powered Rocket Guidance System: A Comprehensive Overview
0:00 Introduction: The video discusses a high-powered rocket designed to reach Mach 3, featuring unique fin tabs for yaw, pitch, and roll control, enhancing stability and reducing recovery dispersion.
0:00:44 Guidance System: The core of the guidance system is the Ava flight computer (All Vehicle Avionics), designed in 2020, responsible for controlling the servos that adjust the fin tabs.
0:00:54 Guidance Package: Houses the Ava flight computer, telemetry radio, GPS antenna, three GoPro Hero 10 cameras, and a VGA cable for servo connections.
0:01:06 VGA Cable for Servo Control: A VGA cable (technically HD15) is cleverly used to connect the guidance package to the four servos, utilizing its 16 lines for redundant power, ground, and signal connections.
0:02:43 Drogue Parachute Deployment: The VGA connection is designed to break cleanly at apogee (peak altitude) to deploy the drogue parachute, which is stored within the guidance package.
0:03:01 Avionics Bay Construction: The avionics bay is built using a carbon fiber coupler tube with a fiberglass switch band, meticulously crafted for consistent outer diameter and strength.
0:03:24 Safety Precautions: The presenter emphasizes safety, particularly when working with fiberglass and carbon fiber, advocating for respirator use and proper air filtration to handle dust particles.
0:05:17 Camera Modifications: GoPro Hero 10 cameras are modified for 4K 120 FPS recording without overheating by adding a substantial aluminum heat sink and potting the assembly in epoxy.
0:06:23 Camera Mounting and Shrouds: Three cameras are strategically mounted (up, down, and horizon views) and secured with epoxy. Custom shrouds are created to protect the lenses during high-speed flight.
0:08:22 Power Switches and Safety: Two power switches are incorporated: one for the guidance package and another for the servos, providing a safety mechanism to disable active control if needed.
0:08:54 Active Control Risks: The presenter stresses the high-risk nature of active control in high-powered rocketry, urging responsible implementation, thorough simulation, and having a failsafe to detach control surfaces.
0:10:12 Power Switch Installation: Finger Tech Robotics power switches, designed for high current capacity, are installed and potted with epoxy for secure placement.
0:11:25 Power Considerations: The video details the power requirements of the system, including GoPros, telemetry radio, Ava flight computer, and servos, calculating a total intermittent draw of 12-13 amps.
0:12:19 Battery Selection and Modification: An 8,000 milliamp-hour battery with a 100C rating is chosen for ample power reserve. It's modified to fit within the avionics bay and secured with Kevlar pulp-filled epoxy.
0:13:56 Bulkhead Fabrication: Bulkheads are cut from thick, quasi-isotropic carbon fiber using a CNC machine, with meticulous attention to dust collection and personal safety.
0:15:49 Lower Bulkhead Assembly: The lower bulkhead includes connectors for explosive charges (drogue parachute deployment), a threaded rod with an eye nut, and a cutout for the VGA cable, all epoxied securely.
0:16:25 Upper Bulkhead and Antennae: The upper bulkhead houses the GPS and telemetry antennae, with careful consideration for RF signal transparency due to the carbon fiber construction.
0:17:19 Camera Wiring and Current Sensing: A system is devised to monitor camera recording status by sensing current draw using resistors, ensuring reliable footage capture.
0:18:28 VGA Connector Wiring and Labeling: The VGA connector is meticulously wired to the booster section, with clear labeling of axes to prevent ambiguity in the full yaw, pitch, and roll control system.
0:20:44 Flight Computer and Mounting: The Ava flight computer (red version for guidance) is mounted on a 3D-printed sled attached to the upper bulkhead, ensuring stability during flight.
0:21:35 Hot Glue Incident and Power Cycling: An unfortunate incident occurs where hot glue is liberally applied to the Ava flight computer, leading to a power cycling issue and eventual damage to the processor.
0:23:34 Servo Torque Limitations: Testing reveals that the servos may have slightly limited torque due to resistance in the long cabling and connectors, requiring careful dynamic limiting of deflection.
0:24:37 Hot Glue Removal and Flight Computer Replacement: The damaged Ava is replaced with a new one, and the hot glue is removed using IPA, resolving the power issue.
0:26:11 Conformal Coating: As a proper solution to prevent foreign object debris (FOD) shorting, silicone conformal coating is applied to the new Ava flight computer, offering protection and a cool UV-fluorescent effect.
0:26:55 Simulation and Control System: The presenter discusses the complex process of CFD (Computational Fluid Dynamics) simulation and control system design, emphasizing iterative refinement and simplification for efficient code implementation.
0:29:32 Axis Checks: Thorough axis checks are performed using software-in-the-loop (SITL) functionality to ensure the fin tabs move correctly in response to simulated flight conditions.
0:30:19 Responsible Active Control Advocacy: The presenter strongly advocates for responsible and careful implementation of active control in high-powered rocketry, emphasizing safety, simulation, and informed decision-making to maintain the sport's unregulated status.
0:31:03 Closing Remarks and Sponsorship: The video concludes with a call to action for viewers to support the project through Patreon or YouTube channel memberships and introduces Incog as a sponsor, highlighting their data privacy service.