Autonomous Vehicle Decision Explainability via POMDP Mediator

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Solution Overview

Problem

Current autonomous driving systems lack explainability, making it difficult for users, developers, and regulators to understand the reasoning behind the vehicle's actions, as decision-making systems like neural networks operate as unexplainable black boxes.

Innovation Solution

An autonomous vehicle operational management system that includes scenario-specific operational control evaluation modules (SSOCEMs) using Partially Observable Markov Decision Process (POMDP) models to determine actions and provide human-understandable explanations, with semantic attachments that describe the decision-making process in terms of state factors and actions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If neural networks and decision-making systems are used for autonomous driving, then the vehicle can perform complex decision-making tasks, but the system becomes unexplainable and operates as a black box

Engineering Contradiction:
Improvedecision-making capabilityVSAvoidexplainability
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The patent introduces an explanation generation module as an intermediary between the decision-making system and users. This module translates the internal state factors and decision logic into human-understandable explanations, allowing the complex neural network to maintain its decision-making capability while providing interpretable output through a mediating layer

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the purely mathematical black-box neural network with a hybrid system that incorporates symbolic reasoning and natural language generation. This substitution introduces interpretable components that can articulate decision reasons in human language while maintaining the underlying neural network's decision-making functionality

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If complex decision-making systems are implemented, then autonomous driving performance improves, but understanding and debugging by developers becomes difficult

Engineering Contradiction:
Improveautonomous driving performanceVSAvoiddebuggability
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The patent segments the decision-making process into distinct state factors (e.g., safety factors, comfort factors, efficiency factors) that can be independently analyzed and explained. This segmentation allows developers to debug specific aspects of decision-making by examining individual state factors and their contributions to the final decision

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements feedback loops where the explanation generation module provides information about decision reasoning back to developers and users. This feedback mechanism enables iterative debugging and improvement by allowing developers to understand how the system arrived at specific decisions and make targeted adjustments

Inventive Principle:
Principle #23Feedback

3Productivity

If autonomous vehicle systems operate autonomously, then operational efficiency increases, but user trust decreases due to lack of explainability

Engineering Contradiction:
Improveoperational efficiencyVSAvoiddecision transparency
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The explanation generation module serves as an intermediary that bridges the autonomous system and user understanding. It maintains operational efficiency by not interfering with the core decision-making process while simultaneously providing transparent explanations that build user trust through articulated reasoning

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS11577746B2Explainability of autonomous vehicle decision making
Publication Date: 2023.02.14 NISSAN MOTOR CO LTD
  • US11577746B2 patent drawing
  • US11577746B2 patent drawing
  • US11577746B2 patent drawing

AI summary

A processor is configured to execute instructions stored in a memory to determine, in response to identifying vehicle operational scenarios of a scene, an action for controlling the AV, where the action is from a selected decision component that determined the action based on level of certainty associated with a state factor; generate an explanation as to why the action was selected, such that the explanation includes respective descriptors of the action, the selected decision component, and the state factor; and display the explanation in a graphical view that includes a first graphical indicator of a world object of the selected decision component, a second graphical indicator describing the state factor, and a third graphical indicator describing the action.