ANVIL / LOOPY

A small set of boards with separated jobs, each revised as the vehicle changed underneath it.

• On-board computerRuns the flight software and closes the control loop, with its sensor interfaces, actuator outputs and telemetry link.
• Power distributionBattery to regulated rails to consumers, with protection, sequencing and current paths. Several revisions, because a change of propulsion architecture lands on the power board first.
• SensingThe inertial and environmental sensors the control law reads, and the interfaces that carry them to the computer.
• Control interfacesActuator and motor-controller interfaces, kept separate from the low-level signal paths.
• TelemetryThe radio board and its interface to the computer.

• SchematicsSchematic capture in KiCad, with the electrical rule check as a gate.
• PCB design and layoutReturn paths, plane splits, separation between switching and sensing, and the RF section kept away from everything loud.
• Component selectionParts chosen against datasheets and availability, with the operating point checked at end-of-charge voltage rather than at nominal.
• Board bring-upA new revision powered in a defined order, rails before loads.
• Hardware validationA board checked against what it is supposed to do before it is trusted on a vehicle, with what was not checked recorded.
• Revision disciplineEach board carries its iteration, and every change between iterations is written down with its reason.

A telemetry radio on a vehicle has to survive the worst electromagnetic environment on it: the propulsion system it is bolted next to.

• Telemetry linkThe radio link between the vehicle and the ground, the only view into the vehicle while it is off the ground.
• Antenna and radio integrationAntenna position on a small vehicle, where the ground plane is whatever structure is underneath and placement is constrained by the airframe.
• Link robustnessMargin, orientation and the loss of line of sight during a manoeuvre.
• ESC electromagnetic interferenceElectronic speed controllers switch large currents at high rate a few centimetres from the sensing and radio sections: broadband noise into the power distribution and radiated from the motor leads. A layout, filtering and separation problem.
• Ducted fan heritageThe vehicle moved from an electric ducted fan on a higher-voltage pack to a contra-rotating propeller drive with two speed controllers. The electromagnetic problem moved with it: two controllers, a different current and a different switching point.

RelatedTelemetry on the racing sideElectronics skills

• Flight firmwareReal-time flight firmware in C++ on the on-board computer. The electronics side is the pin map, reconciled between schematic and firmware.
• Control lawGuidance and control modelled in MATLAB and Simulink. The avionics has to supply the sensors at the rate it needs and the actuator authority it assumes.
• ReconciliationA board and a firmware that disagree about a pin pass on the bench and fail in flight. Keeping them reconciled is part of the electronics job.

No flight, test result or performance figure is published; campaign results belong to the team.