902.【Design】SkyEdge — Power Line & Transmission Tower Inspection Drone

🔌 Defining the V–I Budget per Flight

In the previous article, we fixed the differentiation of the SkyEdge inspection drone
as numerical specifications—reproducibility, cross-checking, and operational validity.

In this article, we take the next step:
cutting the voltage–current (V–I) budget for a single flight.

This is not about “whether it can fly.”

It is about whether the inspection itself can be completed.

❓ 1. Why the V–I budget must come first

For power-line inspection drones, the following are all governed by power constraints:

Flight duration
Image quality
Reproducibility
Safety margins

If features are added without a V–I budget,
the result is always the same: a drone that is mediocre at everything.

SkyEdge follows this order:

Inspection purpose → Required functions → Power allocation

🗺️ 2. Assumed mission profile

Target: transmission lines and towers
Flight mode: sectional hovering + slow translation
Total flight time: 30 minutes
Active inspection time: 20 minutes
Margin: takeoff, landing, avoidance, return

🧱 3. Power architecture (overview)

Main power: Li-ion battery
Auxiliary power: energy harvesting + storage (standby / preparation only)
High-voltage domain: motors, gimbal, actuators
Low-voltage domain: 65 nm FDSOI (intelligence & imaging)

The design rule is fixed:

All high V–I handling is confined to the 0.35 µm LDMOS domain.

📊 4. V–I budget by subsystem

4.1 Propulsion (dominant consumer)

Item	Voltage	Current	Power
Motors ×4 (cruise)	22–25 V	6–8 A	130–180 W
Motors ×4 (hover)	22–25 V	8–10 A	180–250 W
Instantaneous peak	22–25 V	>15 A	>350 W

This is not reduced.
Safety always takes precedence over inspection quality.

4.2 Gimbal & attitude assistance

Item	Voltage	Current	Power
Gimbal	12 V	0.3–0.6 A	4–7 W
Attitude assist	12 V	0.2 A	2–3 W

4.3 Visible CMOS + IR (inspection core)

Item	Voltage	Current	Power
Visible CMOS	5 V	0.8–1.2 A	4–6 W
IR (duty-controlled)	5 V	0.4–0.8 A	2–4 W
Average (incl. IR)	—	—	5–7 W

IR is never always-on.
This is a deliberate design decision.

4.4 65 nm FDSOI (intelligence & imaging)

Mode	Power
Inspection operation	1–2 W
Image-processing peak	up to 3 W
Standby	< 100 mW

4.5 Communications & miscellaneous sensors

Item	Power
Communications (intermittent)	1–2 W
IMU / ranging	< 0.5 W
Losses & margin	2–3 W

⚡ 5. Total power during inspection

Average consumption (inspection phase)

Propulsion: 200 W
Gimbal: 6 W
Visible + IR: 6 W
SoC: 2 W
Other: 3 W

Total: ~217 W

🔋 6. Battery capacity sizing

For a 30-minute flight

Required energy:
217 W × 0.5 h ≈ 109 Wh
Safety margin (20–30%):
→ 130–140 Wh class battery

This fits within realistic weight and size constraints.

♻️ 7. Role of energy harvesting (reconfirmed)

Item	Value
Generation capability	10–100 mW
Contribution to flight	None
Usage	Standby, preparation, safety margin
Effect	Higher availability / lower incident rate

By not mixing harvested power into flight propulsion:

Power design is simplified
Fail-safe behavior becomes explicit

🎯 8. Why this V–I allocation is a differentiator

No over-optimization of propulsion
Guaranteed power for imaging, synchronization, and reproducibility
No participation in the “longest flight time” race

The result is:

A power allocation that never sacrifices inspection quality

🧩 9. Summary

SkyEdge’s V–I design is not for:

Maximizing flight duration
Packing in flashy features

It is cut for one purpose only:

To make repeatable, measurable inspections under identical conditions.

Power design never lies.
The V–I budget is the most honest expression of a system’s design philosophy.

This article includes conceptual design elements,
but all numerical values are grounded in realistic system and power design ranges.