This is a ongoing research please don’t share any content on this page without prior permission from the author. (Debojit Das : [email protected])


GitHub Repositories

https://github.com/Debojit-D/Dual_Arm_Manipulation-Addverb_and_IITGN_Robotics.git

https://github.com/Debojit-D/Addverb_Heal_and_Syncro_Hardware.git

Contains the MuJoCo and Gazebo simulations. Also the ROS packages for dual arm control.

Contains the Hardware ROS Packages for Addverb. Heal and Syncro Robots.

Task 1 : Hold and move / shift large objects with two hands (large objects that do not have handles)

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Dual - Arm Object Impedance Formulation

Addverb.jpg

$$ \begin{equation} \boldsymbol{\tau}_{\text{desired}} = \mathbf{J}H^{T} \mathbf{F}{\text{ext}} \end{equation}

$$

$$ \begin{equation} \boldsymbol{\tau}{\text{desired}} = \mathbf{J}H^{T} (\mathbf{F}{\text{impedance}} + \mathbf{F}{\text{null space}}) \end{equation} $$

$$ \begin{equation} \mathbf{F}_{\text{impedance}} = \mathbf{G}^{+} \big[ \mathbf{K}_p (\mathbf{q}_d - \mathbf{q}) + \mathbf{K}_d (\dot{\mathbf{q}}_d - \dot{\mathbf{q}}) \big) \end{equation}

$$

$$ \begin{equation} \mathbf{F}{\text{nullspace}} = (\mathbf{I} - \mathbf{G}^{+} \mathbf{G}) \Phi{\text{o}} \end{equation}

$$

$$ \begin{equation}\boldsymbol{\tau}_{\text{desired}} = \mathbf{J}_H^{T} \bigg[ \mathbf{G}^{+} \Big( \mathbf{K} (\mathbf{q}_d - \mathbf{q}) + \mathbf{K}_d (\dot{\mathbf{q}}d - \dot{\mathbf{q}}) \Big) + (\mathbf{I} - \mathbf{G}^{+} \mathbf{G}) \Phi{\text{o}} \bigg]\end{equation} $$

In the formulation above and the once generated on this page :-

If we assume a soft contact model (assuming full G matrix),

Matrix / Array Dimensions
Grasp Matrix 6 x 12
Hand Jacobian 12 x 12

If we assume a Coulomb Friction Point Contact Model

Matrix / Array Dimensions
Grasp Matrix 6 x 6
Hand Jacobian 6 x 12

Appendix

Grasp Matrix Formulation

Hand Jacobian Formulation

Current Issues

Admittance Control On heal

Trajectory Planning

Internal Forces Determination by Friction - Cone Constrained Force Distribution

RL Self-Learning Page

Object Level Admittance Control

PD Control Block Diagram to reach the Contact Points of the Box

image.png

Hardware Setup

20241227_182650.jpg

Updates


Reinforcement Learning Appraoch to Solve Task 1 : Hold and move / shift large objects with two hands (large objects that do not have handles)

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Redundancy Optimisation Formulation

(To be added later)