Abstract
This work presents a contact-implicit trajectory optimization framework utilizing an analytically solvable contact model to facilitate interactions with hard, soft, and slippery environments. Specifically, we propose a novel contact modeling that can be computed in closed-form, satisfies friction cone constraints and can be embedded into direct trajectory optimization frameworks without complementarity constraints. The closed-form solution decouples the computation of the contact forces from other actuation forces; this property is used to formulate a minimal direct optimization problem expressed with configuration variables only. Our simulation study demonstrates the characteristics and advantages over the rigid contact model and a trajectory optimization approach based on complementarity constraints. The proposed model enables physics-based optimization in a wide range of interactions with hard, slippery, and soft grounds in a unified manner, expressed by two parameters only. By computing trotting and jumping motions for a quadruped robot, the proposed optimization demonstrates the versatility of multi-contact motion planning on various surfaces with different physical properties.
Original language | English |
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Pages (from-to) | 6357 - 6364 |
Number of pages | 8 |
Journal | IEEE Robotics and Automation Letters |
Volume | 5 |
Issue number | 4 |
Early online date | 21 Jul 2020 |
DOIs | |
Publication status | Published - 1 Oct 2020 |
Keywords / Materials (for Non-textual outputs)
- Optimization and Optimal Control
- Multi-Contact Whole-Body Motion Planning and Control
- Contact Modeling
- Legged Robots