Paper Link: https://tactx-corl.github.io/TACTX.pdf

Tactile policies usually only work wit h the sensor they were trained on

TACTX aligns 3 sensors that measure touch in different ways:

  • Daimon DM-Tac W: vision-based outputs images
  • eFlesh: magnetic, outputs a small vector of field readings
  • FlexiTac: resistive, outputs a pressure grid

Training

2 sensors were mounted on opposite fingers of a Franka gripper, 3rd sensor was swapped in for other runs which covered all 3 sensor pairs in both left/right orders (6 setups)

They collected 2670 trajectories, about 145k frames, 20% held out for validation

Made look-alike housings so sensors could not be distinguished by their casing

Loss:

  1. Reconstruction (L1): each sensor rebuilds its own reading, and also its partner’s reading from shared latent
  2. Contrastive alignment: Two sensors’ readings of the same contact are pulled together
  3. KL regularization: Each sensor’s latent distribution is kept close to a standard normal
  4. Warm-up: Contrastive and KL weights ramp up from zero, so the model learns to reconstruct

Settings: Adam, learning rate 1e-4, batch size 64, 300 epochs