Real-to-simulation matching of deformable soft tissue using position-based dynamics

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Solution Overview

Problem

Current data-driven approaches for interacting with dynamic objects, such as liquids and deformable materials, fail to generalize beyond their training data and lack an explicit model of the real world, making it difficult to navigate and manipulate complex environments effectively.

Innovation Solution

A method for generating and updating a simulation of objects using sensory data, which involves detecting objects, initializing and predicting simulator geometry and parameters, computing and minimizing loss between predicted and received data, and continuously updating the simulation to match the physical world, utilizing techniques like gradient descent and Position-Based Dynamics simulators.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If data driven approaches are used to replicate human ability to handle dynamic objects, then the system can learn from demonstrations and interact with the environment, but the approach fails to generalize to tasks outside training data and lacks an explicit model of the real world

Engineering Contradiction:
Improvegeneralization abilityVSAvoidexplicit model of real world
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent creates a digital copy (simulation) of the physical environment and objects, including their dynamic properties. This simulation copy is continuously updated to match real-world sensory data, providing an explicit model that can be manipulated without physical interaction. The simulation serves as a virtual replica that generalizes across different tasks while maintaining fidelity to real-world physics and object properties.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent introduces a simulation environment as an intermediary between the robot and the physical world. This intermediary layer provides an explicit model of real-world dynamics, allowing the system to learn and generalize from the simulation without directly interacting with physical objects for every task. The simulation acts as a mediator that bridges the gap between training data and new tasks.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If complex simulations with detailed physics models are used to accurately represent deformable objects, then the simulation fidelity improves, but the computational complexity and processing time increase significantly

Engineering Contradiction:
Improvesimulation fidelityVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses dynamic updating of the simulation based on incoming sensory data. Rather than maintaining a static complex model, the simulation is continuously adapted and updated only when new sensory information is available. This dynamic approach maintains high fidelity where needed while reducing computational burden by updating only necessary portions of the simulation state.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameters of the simulation model based on observed real-world data. Instead of using fixed complex physics parameters, the simulation parameters are continuously adjusted to match observed behavior of deformable objects. This allows the system to maintain accuracy by adapting parameters rather than relying on pre-computed complex models for every scenario.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If continuous updating of simulation from sensory data is performed to maintain real-to-sim matching, then the explicit model accuracy improves, but the processing time and computational resources increase

Engineering Contradiction:
Improvereal-to-sim matching accuracyVSAvoidprocessing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements periodic updating of the simulation at specific time intervals or when new sensory data is available, rather than continuous real-time updating. This periodic approach maintains the accuracy of the explicit model by regularly synchronizing with real-world observations while reducing computational load by not constantly processing and updating the simulation state.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentUS20240157559A1Real-to-simulation matching of deformable soft tissue and other objects with position-based dynamics for robot control
Publication Date: 2024.05.16 RGT UNIV OF CALIFORNIA
  • US20240157559A1 patent drawing
  • US20240157559A1 patent drawing
  • US20240157559A1 patent drawing

AI summary

A method is provided for generating and updating a simulation of one or more objects from sensory data. The method includes: (i) receiving sensory data; (ii) detecting one or more objects in the sensory data; (iii) initializing both a simulator geometry of the one or more objects in a simulator and simulator parameters used in the simulator; (iv) predicting the simulator geometry using the simulator parameters; (v) computing predicted sensory data from the predicted simulator geometry; (vi) computing a loss between the predicted sensory data and the received sensory data; (vii) updating the simulator geometry and the simulator parameters by minimizing the computed loss; (viii) repeating (i)-(viii) if new sensory data is received; and (ix) providing a simulation of the one or more objects using the updated simulator geometry and the updated simulator parameters.