A Brain-inspired Hierarchical Framework for Zero-Shot Robot Task Reasoning and Execution
Authors: Guangming Wang, Pengfei Ye, Qizhen Ying, Yixiong Jing, Yuxiang Ma, Haonan Chen, Haibing Wu, Olaf Wysocki, Molong Duan, Brian Sheil
Organizations: Department of Engineering, University of Cambridge, Cambridge, U.K. · Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, MA, USA · Department of Mechanical and Aerospace Engineering, Hong Kong University of Science and Technology, Hong Kong, China · Department of Engineering Science, University of Oxford, Oxford, U.K. · Computer Science and Kempner Institute, Harvard University, Cambridge, MA, USA
Robots that follow open-ended language instructions need to connect semantic intent to visual scene understanding, geometric feasibility, object states, and physical interaction conditions. End-to-end Vision-Language-Action policies have improved cross-task generalization, but they typically map visual and language inputs directly to robot actions, leaving limited explicit structure for long-horizon decomposition, physical verification, and recovery. We present \method, a zero-shot hierarchical framework functionally inspired by the division of roles in the human brain, comprising visual perception and state inference, language grounding and action-sequence generation from a shared atomic action library, cost-based plan selection, and real-robot execution and verification. The framework grounds commands in explicit object states, composes reusable atomic actions into task-conditioned sequences, ranks alternative sequences by execution cost, and verifies intermediate physical outcomes from refreshed observations. In the evaluation, \method{} completes 10/10 clean board trials, 10/10 pick-and-place trials, and 4/5 pyramid stacking trials for both the flat and irregular initial-layout conditions; the corresponding mean task progress is 99.03%, 100.00%, and 96.67% respectively. Across all evaluated conditions, \method{} achieves higher success rates than ReKep, Dream2Flow, and π0.5 benchmarks, demonstrating the effectiveness of combining explicit object-state reasoning, compositional atomic actions, cost-based plan selection, and closed-loop execution verification.
Figures & tables
Fig. 1: Overview of ActionReasoning 2.0. (A) A natural-language command specifies the robot task. (B) A brain-inspired hierarchy organizes perception and state inference, language grounding and atomic-action composition, and cost-based plan selection through functional analogies to the visual cortex, cerebellum, and prefrontal cortex. (C) The resulting task plans are executed on real robots across construction and surface-cleaning tasks, with updated observations supporting verification until task completion.
Fig. 2: Brick-construction data flow. RGB-D and language inputs feed object-state, action-generation, and decision roles. Unique assignments are dispatched directly, surplus alternatives are optimized, and placement ends with a checked Release .
Task
Grounded objective
Action-sequence composition
Feasibility and verification conditions
Pick-and-Place
Transfer the commanded object to the grounded target region or pose
Reachability, collision, contact condition, board boundary, residual mask, and coverage
TABLE I: Task-dependent action-sequence composition, feasibility checks, and execution verification using the shared atomic action library.
Task
Task progress TPr
Success criterion
Pick-and-Place
Verified blocks transferred to the bowl / required blocks
TPr=100%
Pyramid Stacking
Verified bricks correctly placed / target bricks
TPr=100% and stable final structure
Clean Board
100(1−∣DT∣/∣D0∣)
TPr>80%
TABLE II: Task-progress definitions and terminal success criteria.
Condition
Method
SR (%; ns/N )
Time (s)
TP (%)
Clean Board
ReKep
0; 0/10
–
15.22 ± 19.35
Dream2Flow
10; 1/10
93.0
52.93 ± 26.50
π0.5
30; 3/10
124.0 ± 9.67
42.46 ± 42.27
ActionReasoning 2.0 (ours)
100; 10/10
171.3 ± 28.65
99.03 ± 1.67
Pick-and-Place
ReKep
10; 1/10
279.0
53.33 ± 28.11
Dream2Flow
0; 0/10
–
53.33 ± 17.21
TABLE III: Comparison with ReKep, Dream2Flow, and π0.5 across the three task families. SR reports success rate and successful trials; completion time is computed over successful trials only; TP reports mean ± sample standard deviation over all trials.
Fig. 3: Selected Pick-and-Place rollouts (rows: ActionReasoning 2.0, π0.5 , ReKep, and Dream2Flow). Frames progress from left to right. Purple highlights an externally introduced human disturbance, yellow a step-level execution error, green task completion, and red an incomplete terminal outcome.
Fig. 4: Selected Clean Board rollouts in the same row order as Fig. 3 . Yellow highlights the onset of ineffective wiping caused by a stall or missed region, green task completion, and red incomplete cleaning. Quantitative success is defined by TP>80% .
Fig. 5: Selected Pyramid Stacking rollouts for nominal and recovery ActionReasoning 2.0 cases, π0.5 , and ReKep. Yellow highlights the onset of a failed grasp, green task completion or repaired case, and red incomplete construction. The repaired case shows ActionReasoning 2.0 reorienting an irregularly placed brick to a flat state before continuing construction.
Condition
Variant
SR [-1pt] ns/N (%)
TP [-1pt] (%)
Clean Board
Full ActionReasoning 2.0
10/10 (100)
99.03 ± 1.67
Single agent
8/10 (80)
91.55 ± 16.38
Single LLM
0/10 (0)
0.00 ± 0.00
Pick-and-Place
Full ActionReasoning 2.0
10/10 (100)
100.00 ± 0.00
Single agent
7/10 (70)
86.67 ± 23.31
Single LLM
8/10 (80)
93.33 ± 14.05
TABLE IV: Component ablations. TP reports mean ± sample standard deviation.