EVOLV/wiki/Archive/architecture-group-optimization.md

title, created, updated, status, tags, sources

title	created	updated	status	tags	sources
Group Optimization Architecture	2026-04-07	2026-04-07	proven	machineGroupControl optimization BEP-Gravitation	nodes/machineGroupControl/src/specificClass.js

machineGroupControl Optimization

Algorithm: BEP-Gravitation + Marginal-Cost Refinement

Step 1 — Pressure Equalization

Sets all non-operational pumps to the group's max downstream / min upstream pressure. Ensures fair curve evaluation across combinations.

Step 2 — Combination Enumeration

Generates all 2^n pump subsets (n = number of machines). Filters by:

• Machine state (excludes off, cooling, stopping, emergency)
• Mode compatibility (execsequence allowed in auto)
• Flow bounds: sumMinFlow ≤ Qd ≤ sumMaxFlow
• Optional power cap

Step 3 — BEP-Gravitation Distribution (per combination)

1. BEP seed: estimatedBEP = minFlow + span * NCog per pump
2. Slope estimation: samples dP/dQ at BEP ± delta (directional: slopeLeft, slopeRight)
3. Slope redistribution: iteratively shifts flow from steep to flat curves (weight = 1/slope)
4. Marginal-cost refinement: after slope redistribution, shifts flow from highest actual dP/dQ to lowest using real inputFlowCalcPower evaluations. Converges regardless of curve convexity. Max 50 iterations, typically 5-15.

Step 4 — Best Selection

Pick combination with lowest total power. Tiebreak by deviation from BEP.

Step 5 — Execution

Start/stop pumps as needed, send flowmovement commands in output units via _canonicalToOutputFlow().

Three Control Modes

Mode	Distribution	Combination Selection
optimalControl	BEP-Gravitation + refinement	exhaustive 2^n
priorityControl	equal split, priority-ordered	sequential add/remove
priorityPercentageControl	percentage-based, normalized	count-based

Key Design Decision

The flowmovement command sends flow in the machine's output units (m3/h), not canonical (m3/s). The _canonicalToOutputFlow() helper converts before sending. Without this conversion, every pump stays at minimum flow (the critical bug fixed on 2026-04-07).