Robot Obstacle Avoidance Using Dynamic SNN Thresholds

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Solution Overview

Problem

Existing spiking neural networks (SNNs) for obstacle avoidance in robots focus solely on synaptic plasticity, ignoring intrinsic plasticity of neurons, which limits their ability to maintain homeostasis and adapt to degraded environments, leading to inefficiencies in energy consumption and navigation.

Innovation Solution

A biologically reasonable dynamic energy-time threshold method is introduced, comprising a dynamic energy threshold and a dynamic time threshold, integrated to maintain homeostasis and enhance the expressive capacity of SNNs, replacing static thresholds with formulas that correlate membrane potential and depolarization rates to adapt to changing environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If static thresholds are used in SNN, then the model structure is simple, but the ability to maintain homeostasis and adapt to degraded environments is limited

Engineering Contradiction:
Improveadaptability to degraded environmentsVSAvoidmodel structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by replacing static thresholds with dynamic thresholds that adapt over time. Specifically, it introduces a dynamic energy threshold that evolves based on network activity statistics and a dynamic time threshold that adjusts based on spike timing patterns. This allows the SNN to maintain homeostasis and adapt to degraded environments while preserving biological plausibility.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by making the threshold parameters dynamic rather than fixed. The energy threshold is updated based on running statistics of membrane potentials and spike rates, while the time threshold adapts based on inter-spike intervals. These parameter changes enable the network to maintain intrinsic plasticity homeostasis without requiring complex architectural modifications.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If intrinsic plasticity is ignored in SNN, then the model is simpler to implement, but the expressive capacity and homeostasis maintenance are limited

Engineering Contradiction:
Improveexpressive capacityVSAvoidimplementation complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies segmentation by separating intrinsic plasticity into two distinct threshold mechanisms: the dynamic energy threshold that operates on a slower timescale to maintain global homeostasis, and the dynamic time threshold that operates on a faster timescale to capture local temporal patterns. This segmentation allows each mechanism to be implemented independently while working together to enhance expressive capacity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements feedback mechanisms where the dynamic energy threshold is updated based on feedback from network-wide activity statistics (mean membrane potential and coefficient of variation), and the dynamic time threshold is updated based on feedback from local spike timing patterns. This feedback-driven adaptation enables intrinsic plasticity without requiring complex supervisory signals.

Inventive Principle:
Principle #23Feedback

3Reliability

If dynamic thresholds with biological background are applied, then homeostasis is maintained better, but the computational overhead increases

Engineering Contradiction:
Improvehomeostasis maintenanceVSAvoidcomputational energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies self-service by designing threshold update mechanisms that use only information already available in the network during normal operation. The dynamic energy threshold is computed from existing membrane potential and spike rate statistics, while the dynamic time threshold is computed from existing spike timing data. This self-service approach maintains homeostasis without requiring additional computational resources or external control signals.

Inventive Principle:
Principle #25Self-service

Data Source

PatentUS11911902B2Method for obstacle avoidance in degraded environments of robots based on intrinsic plasticity of SNN
Publication Date: 2024.02.27 DALIAN UNIV OF TECH
  • US11911902B2 patent drawing
  • US11911902B2 patent drawing
  • US11911902B2 patent drawing

AI summary

A method for obstacle avoidance in degraded environments of robots based on intrinsic plasticity of an SNN is disclosed. A decision network in a synaptic autonomous learning module takes lidar data, distance from a target point and velocity at a previous moment as state input, and outputs the velocity of left and right wheels of the robot through the autonomous adjustment of the dynamic energy-time threshold, so as to carry out autonomous perception and decision making. The method solves the difficulty of the lack of intrinsic plasticity in the SNN, which leads to the difficulty of adapting to degraded environments due to the homeostasis imbalance of the model, is successfully deployed in mobile robots to maintain a stable trigger rate for autonomous navigation and obstacle avoidance in degraded, disturbed and noisy environments, and has validity and applicability on different degraded scenes.