RRigPI. Read the paper
RESEARCH PROJECT / IROS 2026

RigPIDynamic Parameter Identification of Rigid Body via VLM-Seeded Differentiable Simulation

Recovering physical parameters from real robot interactions through vision-language priors and differentiable physics.

Xincheng He·Rongrong Zhang·Wei Jiang·Wenqiang Xu
RIGPI PIPELINE01 — 03
01
OBSERVEReal-world interactionMotion · Force · Torque
02
INITIALIZEVLM-seeded priorInformed start · Feasible bounds
03
REFINEDifferentiable simulationGradient-based optimization
IDENTIFIED PARAMETERSθ = { m, c, I, μ }
PHYSICAL PARAMETER IDENTIFICATIONSCROLL TO EXPLORE

From interaction
to physical insight.

A robot can see an object move and feel the forces it applies. RigPI turns those observations into a physically grounded model.

Identifying mass, center of mass, inertia, and friction from real-world data is difficult when measurements are noisy and the starting guess is poor. RigPI combines vision-language model priors with a differentiable simulator to initialize, constrain, and refine these parameters.

mMassHow heavy
cCenter of massWhere weight acts
IInertiaHow it rotates
μFrictionHow it resists motion

A closed loop between
reality and simulation.

RigPI uses recorded interaction data to refine a simulator until its predicted trajectory agrees with the observed motion.

RigPI framework: real-world trajectories and forces feed a differentiable simulation loop that optimizes object parameters
FIGURE 01 RigPI framework: real observations, simulation, and iterative parameter refinement.

Three stages.
One consistent model.

Semantic priors help the optimization start in a plausible region; physics and observed motion guide the final estimate.

01 / SENSE

Record interaction

Collect the robot’s applied forces and torques together with the object’s observed pose trajectory.

02 / SEED

Establish a prior

Use visual semantic cues to initialize physical properties and define a feasible parameter range.

03 / REFINE

Fit the simulation

Differentiate through the simulated trajectory and update parameters to reduce the observed pose error.

See RigPI
in motion.

Watch the project video for the real-world setup and trajectory reproduction.

Open video in Drive

Read more.
Build on it.

RigPI is an IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) 2026 paper.

BIBTEX
@article{he2026rigpi,
  title={RigPI: Dynamic Parameter Identification of Rigid Body via VLM-Seeded Differentiable Simulation},
  author={He, Xincheng and Zhang, Rongrong and Jiang, Wei and Xu, Wenqiang},
  journal={arXiv preprint arXiv:2606.25212},
  year={2026}
}