T2 18650 pose surrogate optimization#

Tier-2 pose-aware battery layout benchmark with switchable analytic, promoted explicit-circuit, or promoted hybrid-thermal scoring.

See Optimization Problem Catalog for the optimization family index.

Quick Facts#

Field

Value

Problem ID

battery_18650_t2_pose_surrogate_opt

Problem Family

optimization

Implementation

design_research_problems.problems.optimization._battery_tiers:Battery18650T2PoseSurrogateOptimizationProblem

Capabilities

baseline-solver, bounded-variables, statement-markdown

Study Suitability

none

Tags

optimization, battery, tiered, tier-2, pose-layout, surrogate

Taxonomy#

Formulation

mixed_discrete_optimization

Convexity

nonconvex

Design Variable Type

mixed

Is Dynamic

no

Orientation

engineering_practical

Feasibility Ratio Hint

0.05

Objective Mode

single

Constraint Nature

hard

Bounds Summary

series/parallel plus per-cell pose variables for up to max_cell_count cells

Tags

optimization, battery, tiered, tier-2, pose-layout, surrogate

Benchmark Contract#

Benchmark Question

How well do methods handle continuous pose and packing decisions when electrical and thermal behavior remain surrogate-level?

Physically Modeled

Finite-cylinder collision and clearance geometry; Bounding-box envelope and design volume; Steady-state thermal proxy under a fixed load

Deliberate Surrogates

Topology remains rectangular and electrically analytic; Backend configuration is accepted for provenance but not applied end-to-end; Thermal behavior remains low-order rather than transient electro-thermal simulation

Representation Mode

pose_layout

Default Evaluation Mode

analytic_surrogate

Supported Evaluation Modes

analytic_surrogate, explicit_circuit, hybrid_thermal

Validation Scope

Geometric validity checks; Monotonicity and deterministic surrogate checks

Solver Role

deterministic baseline search

Statement#

Optimize rectangular battery packs with full per-cell pose freedom using [x,y,z,angle_x,angle_y,angle_z] variables under spacing and envelope constraints.

Tier-2 keeps tier-1 electrical topology semantics (S and P) but unlocks 3D pose decisions for each potential active cell.

Geometry model:

  • Each cell is an oriented finite cylinder.

  • Feasibility uses minimum surface clearance between cell bodies.

  • Envelope dimensions come from the axis-aligned bounding box.

  • V_design = width * depth * height.

Electrical and thermal terms follow the same baseline approximation as tier-1:

  • V_pack ~= S * V_cell

  • C_pack ~= P * C_cell

  • I_cell = I_load / P

  • Q_dot = N_cells * I_cell^2 * R_int

  • T_max = T_ambient + Q_dot / (G_passive + hA)

Problem Shape#

Field

Value

Design Variable Count

146

Bound Summary

series/parallel plus per-cell pose variables for up to max_cell_count cells

Total Constraint Count

10

Equality Constraint Count

0

Inequality Constraint Count

10

Variable Bounds#

Variable

Lower Bound

Upper Bound

x[0]

1

24

x[1]

1

24

x[2]

0

500

x[3]

0

500

x[4]

0

250

x[5]

-180

180

x[6]

-180

180

x[7]

-180

180

x[8]

0

500

x[9]

0

500

x[10]

0

250

x[11]

-180

180

x[12]

-180

180

x[13]

-180

180

x[14]

0

500

x[15]

0

500

x[16]

0

250

x[17]

-180

180

x[18]

-180

180

x[19]

-180

180

x[20]

0

500

x[21]

0

500

x[22]

0

250

x[23]

-180

180

x[24]

-180

180

x[25]

-180

180

x[26]

0

500

x[27]

0

500

x[28]

0

250

x[29]

-180

180

x[30]

-180

180

x[31]

-180

180

x[32]

0

500

x[33]

0

500

x[34]

0

250

x[35]

-180

180

x[36]

-180

180

x[37]

-180

180

x[38]

0

500

x[39]

0

500

x[40]

0

250

x[41]

-180

180

x[42]

-180

180

x[43]

-180

180

x[44]

0

500

x[45]

0

500

x[46]

0

250

x[47]

-180

180

x[48]

-180

180

x[49]

-180

180

x[50]

0

500

x[51]

0

500

x[52]

0

250

x[53]

-180

180

x[54]

-180

180

x[55]

-180

180

x[56]

0

500

x[57]

0

500

x[58]

0

250

x[59]

-180

180

x[60]

-180

180

x[61]

-180

180

x[62]

0

500

x[63]

0

500

x[64]

0

250

x[65]

-180

180

x[66]

-180

180

x[67]

-180

180

x[68]

0

500

x[69]

0

500

x[70]

0

250

x[71]

-180

180

x[72]

-180

180

x[73]

-180

180

x[74]

0

500

x[75]

0

500

x[76]

0

250

x[77]

-180

180

x[78]

-180

180

x[79]

-180

180

x[80]

0

500

x[81]

0

500

x[82]

0

250

x[83]

-180

180

x[84]

-180

180

x[85]

-180

180

x[86]

0

500

x[87]

0

500

x[88]

0

250

x[89]

-180

180

x[90]

-180

180

x[91]

-180

180

x[92]

0

500

x[93]

0

500

x[94]

0

250

x[95]

-180

180

x[96]

-180

180

x[97]

-180

180

x[98]

0

500

x[99]

0

500

x[100]

0

250

x[101]

-180

180

x[102]

-180

180

x[103]

-180

180

x[104]

0

500

x[105]

0

500

x[106]

0

250

x[107]

-180

180

x[108]

-180

180

x[109]

-180

180

x[110]

0

500

x[111]

0

500

x[112]

0

250

x[113]

-180

180

x[114]

-180

180

x[115]

-180

180

x[116]

0

500

x[117]

0

500

x[118]

0

250

x[119]

-180

180

x[120]

-180

180

x[121]

-180

180

x[122]

0

500

x[123]

0

500

x[124]

0

250

x[125]

-180

180

x[126]

-180

180

x[127]

-180

180

x[128]

0

500

x[129]

0

500

x[130]

0

250

x[131]

-180

180

x[132]

-180

180

x[133]

-180

180

x[134]

0

500

x[135]

0

500

x[136]

0

250

x[137]

-180

180

x[138]

-180

180

x[139]

-180

180

x[140]

0

500

x[141]

0

500

x[142]

0

250

x[143]

-180

180

x[144]

-180

180

x[145]

-180

180

Manifest Parameters#

Key

Value

ambient_temperature_c

25

cooling_coefficient_w_per_m2k

18

evaluation_mode

analytic_surrogate

load_current_a

60

max_cell_count

24

max_depth_mm

500

max_height_mm

250

max_width_mm

500

maximum_temperature_c

60

minimum_capacity_ah

10

minimum_current_a

60

minimum_spacing_mm

2

objective_weights

{“cost”: 0.35, “temperature”: 0.2, “volume”: 0.45}

passive_cooling_w_per_k

1

target_voltage_v

14.8

voltage_tolerance_v

0.1

Library Interface#

  • generate_initial_solution(seed=None)

  • objective(x)

  • evaluate(x)

  • solve(initial_solution=None, seed=None, maxiter=200)