Grid-Based Multi-Object Tracking for Collision Avoidance Prediction

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Solution Overview

Problem

Existing methods for tracking multiple target objects in dynamic environments are complex and do not effectively account for the spatial correlations and uncertainties in movement patterns, leading to inefficient collision avoidance for robots in busy spaces.

Innovation Solution

A method that projects moving objects onto a grid map, using a trained neural network and multivariate Gaussian model to calculate transitional velocity distributions and occupancy probabilities for each grid cell, allowing for improved prediction of object movements and collision avoidance by considering transitional probabilities and environmental topology.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If individual persons are detected and monitored separately to predict their movement, then prediction accuracy for each person is improved, but system complexity increases significantly

Engineering Contradiction:
Improveprediction accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The environment is divided into grid cells that aggregate multiple objects, allowing movement prediction at the grid level rather than individual object level. This segmentation reduces complexity while maintaining sufficient prediction accuracy for collision avoidance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple individual object tracking tasks are merged into a single grid-based occupancy tracking system. Instead of predicting movements of each person separately, the system predicts occupancy probabilities for grid cells, combining multiple tracking problems into one unified approach.

Inventive Principle:
Principle #5Merging (Combining)

2Device complexity

If grid cells are scanned to detect occupancy without monitoring individual objects, then sensor system requirements are reduced, but movement trajectory prediction capability is weakened

Engineering Contradiction:
Improvesensor system complexityVSAvoidmovement trajectory prediction
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system changes the parameter being tracked from individual object identities to grid cell occupancy probabilities. By using probability distributions over grid cell occupancies and applying Bayesian filtering, the system maintains reliable movement prediction without needing to identify or track individual objects.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Grid cell occupancy probabilities serve as an intermediary representation between raw sensor data and movement trajectory prediction. This intermediate probabilistic model allows the system to bridge the gap between simple occupancy detection and accurate movement prediction.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If Bayesian filtering methods are used to integrate measurement uncertainties, then prediction reliability is improved, but computational complexity increases

Engineering Contradiction:
Improveprediction reliabilityVSAvoidcomputational complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The state space is segmented into discrete grid cells with discrete occupancy states, which simplifies the Bayesian filtering computations compared to continuous state spaces. This discretization maintains prediction reliability while reducing computational complexity.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS11253997B2Method for tracking multiple target objects, device, and computer program for implementing the tracking of multiple target objects for the case of moving objects
Publication Date: 2022.02.22 ROBERT BOSCH GMBH
  • US11253997B2 patent drawing
  • US11253997B2 patent drawing
  • US11253997B2 patent drawing

AI summary

A method for tracking multiple target objects, moving objects to be tracked being projected onto a grid map having grid cells, the method including the following tasks to be executed in each time: computing the velocity distribution for the next time step with the aid of a transition velocity distribution, which indicates how the objects associated with a grid cell in question move from one time step to the next, based on the preceding velocity distribution; for each grid cell, calculating a transitional probability information item, which indicates, for objects in each grid cell, probabilities of the objects in question reaching possible, further grid cells, as a function of the velocity distribution; calculating an occupancy probability for each grid cell for a subsequent time, based on the transitional probability information item; operating a system as a function of the occupancy probabilities for the grid cells.