Odom anchor sets by apirrone · Pull Request #278 · pollen-robotics/microduck

apirrone · 2026-09-13T12:55:52Z

Odometry: anchor points sampled on the alpha sole mesh, 16-point grid by default

The contact odometry picks its ground anchor from a set of candidate points on each sole, expressed in the foot-site frame. Since the port those were four hardcoded corners: the v1.5 sole bbox, ±27.0 × ±20.6 mm on the site's Z = 0 plane, flagged as a placeholder and never measured.

The alpha sole does not look like that. In the site frame it spans X [-20, +34] mm (54 mm long, 7 mm forward of the site), Y ±21 mm, and its bottom is canted 4.9° about X. The old corners float 2 mm above the real contact on one side and sit inside the sole on the other, and the robot stands 2 to 4 mm taller than it is.

What changes

odometry/src/anchors.rs is generated by microduck_rl/scripts/odom_anchor_points.py (PR pollen-robotics/microduck_rl#), which shoots a vertical ray through each sample point and keeps the lowest triangle of the sole collision mesh. Each foot is sampled on its own mesh. Three sets:
- V15: the legacy corners, unchanged.
- ALPHA4: the four corners of the flat contact patch, on the mesh.
- ALPHA16: a 4×4 grid over the whole footprint, bevels included, on the mesh.
Odometry::new takes an &'static AnchorSet; alpha_with(&SET) picks one; Odometry::alpha() now runs ALPHA16. robotd needs no change.
Tests: the generated sets must lie on the sole and mirror between feet; an ignored timing test and an ignored reference-trajectory dump (used to validate the Python replica in microduck_rl, which matches to 27 µm with identical anchor-foot decisions).

Why 16 points

Measured in the MuJoCo twin with infer_policy --odom-compare (perfect IMU, so only the contact geometry differs), 3.2 m of keyboard-driven walking over 23.8 s:

set	pts/foot	final xy err	max xy err	xy err / path	final z err
v15	4	17.3 mm	24.5 mm	0.5 %	+3.7 mm
alpha4	4	15.6 mm	21.6 mm	0.5 %	+0.9 mm
alpha16	16	9.1 mm	19.7 mm	0.3 %	+0.5 mm

The sole is rounded, so when the foot pitches the contact rolls onto the bevel; four corners on the flat patch cannot follow that, the grid can.

Cost

cargo test -p odometry --release -- --ignored --nocapture update_cost_per_anchor_set, x86 laptop:

set	ns per update
4 points	484
16 points	951

On the Zero 3's A55 expect a few µs per 20 ms tick. Negligible.

Checks

fmt, test, clippy, cargo board -p robotd all pass. Not yet validated on the robot: the sim used rigid feet, and the PU sole's compliance may shift the numbers.

🤖 Generated with Claude Code

The contact odometry picked its anchor from four hardcoded corners: the v1.5 sole bbox, ±27.0 x ±20.6 mm on the foot-site Z = 0 plane, a placeholder since the port. The alpha sole is 54 mm long, sits 7 mm forward of the site, and its bottom is canted 4.9° about X in the site frame, so those corners float 2 mm above the real contact on the low side and 3 mm under the mesh on the high side. `anchors.rs` is GENERATED by microduck_rl/scripts/odom_anchor_points.py, which drops a grid of vertical rays onto the sole collision mesh: V15 the legacy corners (unchanged behaviour) ALPHA4 the flat contact patch's four corners, on the mesh ALPHA16 a 4x4 grid over the whole footprint, bevels included `Odometry` takes an `&'static AnchorSet`; `Odometry::alpha()` still uses V15, so robotd is unchanged until the sets have been compared (infer_policy --odom-compare in microduck_rl). `alpha_with(&ALPHA16)` is the switch. Cost, `update_cost_per_anchor_set` on an x86 laptop: 484 ns per update with 4 points per foot, 951 ns with 16. On the Zero 3's A55 expect a handful of µs — nothing next to a 20 ms tick. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_014ZPSQ6nCsfqannMDXwAKZ3

Measured in the MuJoCo twin (infer_policy --odom-compare, perfect IMU, 3.2 m of keyboard-driven walking, 23.8 s): set final xy err max xy err final z err v15 17.3 mm 24.5 mm +3.7 mm alpha4 15.6 mm 21.6 mm +0.9 mm alpha16 9.1 mm 19.7 mm +0.5 mm Odometry::alpha() now runs the 16-point grid. V15 and ALPHA4 stay as named sets for alpha_with() and the cost/reference tests. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_014ZPSQ6nCsfqannMDXwAKZ3

github-actions · 2026-09-13T12:58:51Z

Coverage

71.59% lines on this branch, against a floor of 70%.

Per-file

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btd/src/adv.rs                             79                 0   100.00%           9                 0   100.00%          42                 0   100.00%           0                 0         -
btd/src/bluez.rs                          482               482     0.00%          34                34     0.00%         314               314     0.00%           0                 0         -
btd/src/chorale.rs                        346               246    28.90%          23                13    43.48%         230               171    25.65%           0                 0         -
btd/src/framing.rs                        253                 9    96.44%          20                 1    95.00%         120                 5    95.83%           0                 0         -
btd/src/gatt.rs                             3                 0   100.00%           1                 0   100.00%           3                 0   100.00%           0                 0         -
btd/src/link.rs                            24                 0   100.00%           3                 0   100.00%          26                 0   100.00%           0                 0         -
btd/src/main.rs                            77                77     0.00%          11                11     0.00%          77                77     0.00%           0                 0         -
btd/src/pairing.rs                        149                 2    98.66%          12                 1    91.67%          81                 1    98.77%           0                 0         -
btd/src/route.rs                          352                32    90.91%          27                 0   100.00%         351                11    96.87%           0                 0         -
btd/src/session.rs                       1218                73    94.01%          71                 5    92.96%         706                41    94.19%           0                 0         -
btd/src/upstream.rs                       397                35    91.18%          34                 8    76.47%         241                19    92.12%           0                 0         -
configd/src/bluez.rs                      586               498    15.02%          85                79     7.06%         375               326    13.07%           0                 0         -
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duck-ipc-proto/src/lib.rs                2089               163    92.20%         133                13    90.23%        1530                88    94.25%           0                 0         -
duckctl/src/main.rs                      2617              1023    60.91%         156                45    71.15%        1629               654    59.85%           0                 0         -
kinematics/src/hand.rs                    394                 2    99.49%          22                 2    90.91%         181                 2    98.90%           0                 0         -
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odometry/src/anchors.rs                     5                 0   100.00%           1                 0   100.00%           3                 0   100.00%           0                 0         -
odometry/src/lib.rs                       445                80    82.02%          28                 5    82.14%         254                50    80.31%           0                 0         -
pad-imu/src/lib.rs                        608                 7    98.85%          39                 0   100.00%         372                 5    98.66%           0                 0         -
padd/src/main.rs                         1088               606    44.30%          36                13    63.89%         664               417    37.20%           0                 0         -
padd/src/tap.rs                          1253               682    45.57%          73                36    50.68%         767               407    46.94%           0                 0         -
pet-detect/src/bin/detect.rs               61                61     0.00%           1                 1     0.00%          38                38     0.00%           0                 0         -
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robotctl/src/configure.rs                1596               477    70.11%          61                12    80.33%         820               322    60.73%           0                 0         -
robotctl/src/duck.rs                     1211               144    88.11%          63                 1    98.41%         604                47    92.22%           0                 0         -
robotctl/src/imu_view.rs                  266                25    90.60%          19                 2    89.47%         173                19    89.02%           0                 0         -
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robotctl/src/monitor.rs                  4308               748    82.64%         222                36    83.78%        2721               477    82.47%           0                 0         -
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robotctl/src/show.rs                      714                46    93.56%          31                 1    96.77%         509                25    95.09%           0                 0         -
robotd-params/src/edit.rs                1904               120    93.70%         114                14    87.72%         929                52    94.40%           0                 0         -
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robotd-params/src/registry.rs             193                10    94.82%          15                 2    86.67%         144                17    88.19%           0                 0         -
robotd/src/chorale.rs                    1366                30    97.80%          71                 4    94.37%         826                20    97.58%           0                 0         -
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robotd/src/theremin.rs                    472               112    76.27%          32                12    62.50%         271                64    76.38%           0                 0         -
sounds/src/chorale/beat.rs                403                16    96.03%          26                 1    96.15%         246                12    95.12%           0                 0         -
sounds/src/chorale/midi.rs               1047                80    92.36%          44                 2    95.45%         581                43    92.60%           0                 0         -
sounds/src/chorale/mod.rs                1423                57    95.99%          83                 3    96.39%         812                41    94.95%           0                 0         -
sounds/src/chorale/text.rs                700                60    91.43%          41                12    70.73%         376                17    95.48%           0                 0         -
sounds/src/lib.rs                         167                35    79.04%          14                 6    57.14%          87                21    75.86%           0                 0         -
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sounds/src/personality.rs                 174                 0   100.00%           6                 0   100.00%          84                 0   100.00%           0                 0         -
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sounds/src/synth.rs                       353                 7    98.02%          29                 0   100.00%         197                 3    98.48%           0                 0         -
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test-support/src/lib.rs                   272                 2    99.26%          22                 0   100.00%         167                 0   100.00%           0                 0         -
tof/src/config.rs                          42                 8    80.95%           4                 1    75.00%          23                 7    69.57%           0                 0         -
tof/src/imu.rs                            223               153    31.39%          10                 5    50.00%         137                93    32.12%           0                 0         -
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tof/src/main.rs                           770               687    10.78%          37                26    29.73%         481               437     9.15%           0                 0         -
tof/src/sensor.rs                         230               148    35.65%          22                15    31.82%         163               114    30.06%           0                 0         -
tof/src/status.rs                          76                 2    97.37%           7                 1    85.71%          58                 1    98.28%           0                 0         -
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updater/src/ipc.rs                        925               333    64.00%          67                20    70.15%         569               179    68.54%           0                 0         -
updater/src/journal.rs                    832                78    90.62%          57                10    82.46%         483                53    89.03%           0                 0         -
updater/src/lib.rs                         55                16    70.91%           5                 0   100.00%          41                14    65.85%           0                 0         -
updater/src/main.rs                       550               222    59.64%          38                14    63.16%         420               151    64.05%           0                 0         -
updater/src/manifest.rs                   159                 6    96.23%          16                 0   100.00%         110                 1    99.09%           0                 0         -
updater/src/orphan.rs                     288                 6    97.92%          25                 0   100.00%         181                 3    98.34%           0                 0         -
updater/src/policy.rs                    1549               599    61.33%         124                52    58.06%         830               344    58.55%           0                 0         -
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updater/src/reconcile.rs                  292                15    94.86%          25                 3    88.00%         172                 5    97.09%           0                 0         -
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updater/src/source/github.rs              474               169    64.35%          51                26    49.02%         304                99    67.43%           0                 0         -
updater/src/source/hf_hub.rs              136                72    47.06%          20                12    40.00%          81                41    49.38%           0                 0         -
updater/src/source/http.rs                319                82    74.29%          29                11    62.07%         260                88    66.15%           0                 0         -
updater/src/source/local.rs               346                37    89.31%          36                 9    75.00%         192                26    86.46%           0                 0         -
updater/src/source/mod.rs                  39                30    23.08%           4                 2    50.00%          30                24    20.00%           0                 0         -
updater/src/spawn.rs                       94                13    86.17%           5                 0   100.00%          49                 4    91.84%           0                 0         -
updater/src/store.rs                      593                41    93.09%          43                 7    83.72%         271                42    84.50%           0                 0         -
updater/src/transcript.rs                 518                42    91.89%          31                 3    90.32%         290                22    92.41%           0                 0         -
updater/src/unix.rs                        44                 3    93.18%           3                 0   100.00%          22                 2    90.91%           0                 0         -
updater/src/verify.rs                     786                95    87.91%          55                18    67.27%         424                75    82.31%           0                 0         -
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TOTAL                                   79959             22104    72.36%        5255              1407    73.23%       49941             14186    71.59%           0                 0         -

apirrone and others added 2 commits September 13, 2026 14:19

apirrone merged commit e9cca62 into main Sep 13, 2026
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apirrone deleted the odom-anchor-sets branch September 13, 2026 13:00

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Odom anchor sets - #278

Odom anchor sets#278
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apirrone commented Sep 13, 2026

Odometry: anchor points sampled on the alpha sole mesh, 16-point grid by default

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