Dynamic Inference on Graphs using Structured Transition Models

Enabling robots to perform complex dynamic tasks such as picking up an object in one sweeping motion or pushing off a wall to quickly turn a corner is a challenging problem. The dynamic interactions implicit in these tasks are critical towards the successful execution of such tasks. Graph neural networks (GNNs) provide a principled way of learning the dynamics of interactive systems but can suffer from scaling issues as the number of interactions increases. Furthermore, the problem of using learned GNN-based models for optimal control is insufficiently explored. In this work, we present a method for efficiently learning the dynamics of interacting systems by simultaneously learning a dynamic graph structure and a stable and locally linear forward model of the system. The dynamic graph structure encodes evolving contact modes along a trajectory by making probabilistic predictions over the edges of the graph. Additionally, we introduce a temporal dependence in the learned graph structure which allows us to incorporate contact measurement updates during execution thus enabling more accurate forward predictions. The learned stable and locally linear dynamics enable the use of optimal control algorithms such as iLQR for long-horizon planning and control for complex interactive tasks. Through experiments in simulation and in the real world, we evaluate the performance of our method by using the learned interaction dynamics for control and demonstrate generalization to more objects and interactions not seen during training. We introduce a control scheme that takes advantage of contact measurement updates and hence is robust to prediction inaccuracies during execution.

Authors

• Saumya Saxena
• Oliver Kroemer

Keywords

• Training
• Interactive systems
• Heuristic algorithms
• Dynamics
• Optimal control
• Probabilistic logic
• Prediction algorithms
• Linear Model
• Neural Network
• Model System
• Learning Models
• Control Strategy
• System Dynamics
• Dynamic Interactions
• Structural Dynamics
• Control Model
• Complex Dynamics
• Interactive System
• Dynamic Control
• Forward Model
• Graph Structure
• Scalability Issues
• Graph Neural Networks
• Interaction Task
• Linear Dynamics
• Principled Way
• Dynamic Graph
• Gated Recurrent Unit
• Distractor Objects
• Linear Quadratic Regulator
• Nonlinear Systems
• Objects In The Scene
• Node Embeddings
• Linear Quadratic Regulator Controller
• Learning Behavior
• Expert Demonstrations
• Model Predictive Control