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Powered mechanical parts

Manta's powered variants are opt-in endpoints on the radial DC network. The ordinary Motor, Thruster, DuctedPropeller, and ControlSurface keep their existing direct command behavior. Selecting a powered class is therefore an explicit vehicle-model migration, not a global change in actuator semantics.

from manta.parts import DCSource, PoweredMotor

pack = craft.add(DCSource("pack", open_circuit_voltage=48.0))
fin = craft.add(PoweredMotor(
    "fin_motor",
    torque_constant=0.08,
    resistance=0.6,
    brownout_voltage=30.0,
    recovery_voltage=34.0,
))
pack.connect(fin)

PoweredMotor preserves the motor's signed voltage command. Its winding voltage is clipped to the available rail and fades through the configured brownout interval. Armature current, geared torque, useful shaft power, winding heat, controller loss, and non-regenerative braking heat come from the same DC motor equations. input_power = mechanical_power + loss_power; connect one ThermalMass(source=motor) to dissipated_heat() to capture the loss. Do not also add winding loss as a separate heat_input.

PoweredThruster, PoweredDuctedPropeller, and PoweredControlSurface use a calibrated power-map seam because their underlying primitives contain no motor shaft speed, winding current, gear ratio, or ESC model. They require explicit rated_voltage, rated_mechanical_power, and conversion_efficiency values. They do not infer power from thrust or hinge torque: doing so would invent an advance ratio or servo gear train that the source model does not contain. Voltage and brownout derate the physical command, while the calibrated power map supplies electrical current and loss accounting. Replace these adapters with a resolved motor/propeller model when shaft data is available.

ConstantPowerElectronicsLoad is the compute/device specialization. It uses the bounded constant-power load law, reports zero mechanical output, and sends all consumed power through the thermal-source seam.

ExternalDCSupply is the boundary for a simulation-only battery or a hardware source. Its supplied_voltage input feeds the compiled electrical/load model; its output_current reports aggregate demand back to the external plant. Cell, thermal, degradation, and fault states can consequently remain ordinary simulator state rather than entering Manta's differentiable state vector.

Boundaries and limitations

  • A1 networks are unidirectional. A powered motor absorbs regenerative or dynamic-braking energy as heat instead of returning it to the bus.
  • Converter overload acts through its current/power limits and output capacitor. The resulting rail sag continuously derates powered parts; there is no separate mission-policy cutoff hidden in the actuator.
  • The calibrated propulsor/servo power output is motor-side useful mechanical power, not hydrodynamic propulsive efficiency or aerodynamic work at the vehicle. Those require shaft-resolved primitives.
  • ESC/PWM protocols, vendor calibration, arming, watchdogs, and failsafe policy belong in Shiver. Manta models only the physical plant.