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DRCL-USC / Hector_Simulation

Simulation Software (ROS/MATLAB) for HECTOR Humanoid Robot Locomotion Control/Bipedal Locomotion Control/Force-and-moment-based MPC
https://youtu.be/NcW-NFwjMh0
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confusion about Constraints Matrix #11

Closed BIT-XLJ closed 8 months ago

BIT-XLJ commented 8 months ago

Hello, thanks for your awesome job! But I have some questions about the constraints matrix in SolverMPC.cpp。 2023-12-17 12-01-59屏幕截图 I know the first four rows of F_control are friction pyramid constraints, and the fifth row of F_control aims to guarantee the moment of X axis equals to zero. But what about the function of the last three rows of F_control? I didn't find the details of this code clip in your essay. Could you please explain this to me? Or can somebody help me?

junhengl commented 8 months ago

Hi, row 5&6 are part of line foot constraint for ensuring no toe/heel lifts. You can read more about this in [1]. The last row is force saturation constraint. We put 2 in the Fz slot to avoid bugs in the variable elimination process.

[1] Caron, S., Pham, Q. C., & Nakamura, Y. (2015, May). Stability of surface contacts for humanoid robots: Closed-form formulae of the contact wrench cone for rectangular support areas. In 2015 IEEE International Conference on Robotics and Automation (ICRA) (pp. 5107-5112). IEEE.

BIT-XLJ commented 8 months ago

Thank you so much!