Kimodo-Policy: Learning Kinematic Action Models for Humanoid Loco-Manipulation
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TL;DR Kimodo-Policy turns a frozen pretrained text-to-motion generator into a closed-loop humanoid policy by adding visual ControlNet branches and a hand head. It reaches 72.14% on multi-task HumanoidArena and 60% mean success on eight real-world loco-manipulation tasks with 92M trainable parameters.
What they do
Humanoid policies usually start from a vision-language model or a video model, neither of which is pretrained on robot motion itself. This paper proposes Kinematic Action Models: use a pretrained whole-body motion generator as the action backbone. Kimodo-Policy keeps the Kimodo-G1 text-to-motion model frozen and trains small modules around it so that it reacts to the camera image and the robot’s own executed motion.
How it works
- Visual conditioning. Trainable ControlNet branches feed frozen DINOv3 features of the egocentric image into the frozen root and body denoisers, through cross-attention plus an MLP path, with zero-initialized projections.
- Root, body, hand. The root stage predicts translation and heading, the body stage predicts joint motion given the root, and a separate diffusion head (HandNet) predicts open/close commands for both hands. Gradients are detached between stages.
- Closed loop. Each query is motion completion: up to 100 frames of measured motion history are fixed and 50 future frames (30 Hz) are generated; 15 frames are executed by the SONIC whole-body tracker before replanning.
- Pretraining. The trainable modules are pretrained on 419 hours of public humanoid demonstrations. 678M parameters in total, 92M trainable.
Results
- HumanoidArena, one policy for seven tasks: 72.14% success, against 69.70% for GR00T N1.7. It leads on scene-interaction tasks but trails on object-interaction tasks (about 56.1% against 62.22%).
- SIMPLE, eight tasks: 75.83% against 75.42% for Psi-0, with baseline numbers taken from other reports. Success drops from 87.50% at the easiest randomization level to 68.75% at the hardest.
- Real humanoid, eight tasks, ten trials each: 60% mean success (48/80), against 45% without policy pretraining, 35% for Psi-0 and about 31% for GR00T N1.6.
- Ablation on object-interaction tasks: a randomly initialized backbone gets 18.33%, a fine-tuned pretrained one 31.67%, the frozen pretrained one 51.67%.
Limitations
The policy is built and tested only with the SONIC tracker; other low-level controllers are not supported. Policy pretraining lowers single-task HumanoidArena success (67.14% against 69.76%). Real-world rates come from ten trials per task, and the effect of real-time chunking is not ablated.
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Abstract
Humanoid loco-manipulation requires continuous coordination of high-dimensional whole-body motion to realize task objectives. While vision-language-action models and world action models transfer semantic and visual-dynamics priors to robot control, these priors do not necessarily capture the structure of robot motion. We introduce Kinematic Action Models (KAMs), a paradigm that treats whole-body motion as a direct pretraining target and uses a pretrained motion generator as the primary action-generation backbone. KAMs ground learned temporal and cross-body coordination priors through task conditioning, visual observations, and execution feedback. We present Kimodo-Policy as an initial instantiation, combining a frozen Kimodo text-to-motion backbone with lightweight ControlNet-based visual conditioning. A root-body-hand hierarchy coordinates locomotion and manipulation, while motion-history conditioning and repeated action-chunk prediction bridge motion synthesis and closed-loop control. Following large-scale loco-manipulation pretraining, the policy achieves the highest overall success among compared policies on multi-task HumanoidArena (72.14%), competitive performance on SIMPLE, and 60% mean success across eight real-world tasks, with 678M parameters (92M trainable). Ablations support the contribution of the pretrained motion backbone. Together, these results provide initial evidence for motion generation as a complementary foundation for humanoid action learning.
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