Although vision-language-action (VLA) policies have advanced rapidly, long-horizon execution may still progress to the next task stage before the required physical effect has been established. We call this a mismatch between semantic commitments, physical conditions that a stage must establish or maintain, and the actual physical state. Because an action command alone cannot confirm such a condition, local deviations can propagate and cause task failure. To address this problem, we present CommitFlow, a closed-loop execution framework that combines commitment monitoring with local correction while keeping the base policy frozen. CommitFlow integrates three components. A Semantic Commitment Monitor (SCM) compares stage requirements against current state evidence and holds back dependent actions when a required condition is unmet or violated. BoundaryFlow then generates a local correction conditioned on the current state and base action, and Relation and Gain Calibration (RGC) selects the smallest correction strength that satisfies the relevant constraints. Across the ten common RoboTwin 2.0 benchmark tasks, CommitFlow achieves a mean success rate of 75.9 percent, improving on the base policy pi0.5 by 22.7 percent. Cross-policy experiments show consistent gains, pointing toward reliable long-horizon robot execution.
Figures & tables
Fig. 2: CommitFlow overview. RGB-D encoding supplies visual features, metric relations, and task context. SCM assigns action permissions; BoundaryFlow predicts a base-action-conditioned residual; RGC selects its strength. The permission-gated action is executed, and fresh observations support re-verification.
Fig. 3: BoundaryFlow action generation and local correction. The frozen VLA generates a base action chunk through flow matching, while the trainable BoundaryFlow branch generates a corrective action chunk. Combining the two produces the corrected action chunk.
Fig. 4: RGB-D/CAD localization and SCM recognition performance. (a) Median (P50) and 90th-percentile (P90) position errors in XY and XYZ over all 1,971 closed-loop frames and the 259-frame ALIGN TO GRASP subset. (b) Macro-F1 for stage and event-class recognition across six streams (1,971 frames). The dashed line marks the 95% target.
Method
Handover Block
Handover Mic
Hang Mug
Bread Basket
Bread Skillet
Place A2B Left
Place A2B Right
Object Basket
Object Stand
Object Scale
Object Cabinet
Avg. 10
RDT
45
90
1
10
5
3
1
33
15
1
33
23.6
π0.5
24
58
11
62
62
51
39
69
68
45
54
53.2
π0.5 +TACO [ 14 ]
36
63
–
65
61
56
42
78
78
52
56
58.7
π0.5 +CAPS [ 15 ]
38
72
–
63
69
54
47
76
81
57
58
61.5
π0.5 +CommitFlow
66
60
42
75
78
70
69
88
97
85
71
75.9
TABLE I: RoboTwin 2.0 Results (%)
Fig. 5: Qualitative execution sequences in simulation. Four examples compare the base policy (upper rows) with CommitFlow (lower rows). Frames progress from left to right; marked regions highlight the relevant physical relations.
Fig. 6: Recovery-strength sweep. Cabinet and Basket: overall task success (left axis), recovery-error reduction and zero-crossing overshoot in mm (right axis). Circled annotations highlight selected measurements; the success axis is truncated.
Fig. 7: Qualitative execution sequences on the real robot. Bowl stacking (left) and eraser placement (right), comparing the base policy (upper row) with CommitFlow (lower row). Frames progress from left to right.
Task
π0 [ 20 ]
π0.5 [ 19 ]
LingBot-VLA [ 21 ]
Handover Block
26 → 45
24 → 66
85 → 90
Handover Mic
86 → 89
58 → 60
95 → 96
Hang Mug
3 → 25
11 → 42
49 → 62
Bread Basket
35 → 50
62 → 75
89 → 91
Bread Skillet
12 → 23
62 → 78
80 → 83
Place A2B Left
30 → 45
51 → 70
83 → 83
TABLE II: Cross-Policy Results (%)
Task
Fresh Base
Fresh + IK
Fresh + Ours
Object Cabinet
61
57
71
Object Basket
60
68
88
Place A2B Left
55
57
70
Place A2B Right
56
60
69
Object Scale
78
78
85
Object Stand
91
94
97
TABLE III: Local Correction Ablation (%)
Task
Base
+ CommitFlow
Correction reuse — simulation
Handover Mic
58
65
Can → Basket
40
58
Real-world execution
Eraser → Container
50
63
Stack Three Bowls
40
50
TABLE IV: Correction Reuse and Real-World Results (%)
The Hong Kong University of Science and Technology (Guangzhou), Guangzhou, China. · Zhejiang University, Hangzhou, China. · Simon Fraser University, Burnaby, BC, Canada. +1