Body-Grounded Replanning for Physically Adaptive Manipulation
Organizations: Microsoft Research Asia - Tokyo · Waseda University · Chiba University · National Institute of Informatics
Abstract
Manipulation requires not only reasoning about the external environment, but also about the robot's physical condition. A strategy may remain geometrically feasible while becoming physically unsuitable due to increased joint load or limited mobility, yet internal physical state is typically used only for low-level control. We propose body-grounded high-level replanning, which uses internal physical state to adapt manipulation strategies during execution. Body-state events trigger strategy replanning, and an LLM interprets the underlying joint-level state, recent execution statistics, and execution history to select a context-dependent alternative, while leaving the task objective and low-level controller unchanged. We evaluate the framework on a reaching task under controlled load and asymmetric mobility constraints in simulation and on a real robot. Our experiments show that body-grounded replanning maintains high task success while reducing physical effort and enabling more efficient strategy adaptation. Additional contact-rich manipulation experiments demonstrate the applicability of the same replanning interface beyond reaching. These results show that internal physical state can inform not only low-level control, but also high-level decisions about how a manipulation task should be performed.
Figures & tables
| Success (%) | Mean joint-torque norm | Restricted time [s] | ||||||||||
| Condition | Fixed | Env. | Rule | Ours | Fixed | Env. | Rule | Ours | Fixed | Env. | Rule | Ours |
| Load ( g) | ||||||||||||
| Wrist | 99 | 100 | 91 | 98 | ||||||||
| Forearm | 99 | 100 | 91 | 99 | ||||||||
| Upper arm | 99 | 100 | 92 | 97 | ||||||||
| Mean | 99.0 | 100.0 | 91.3 | 98.0 | ||||||||
| Success (%) | Mean actuator-effort norm | Restricted time [s] | |||||||
| Condition | Env. | Rule | Ours | Env. | Rule | Ours | Env. | Rule | Ours |
| Load ( g) | |||||||||
| Wrist | 100 | 75 | 100 | ||||||
| Forearm | 75 | 75 | 100 | ||||||
| Upper arm | 87.5 | 62.5 | 87.5 | ||||||
| Mean | 87.5 | 70.8 | 95.8 | ||||||