Autonomous Transport Robot Suspension for Low-Slip Localization

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Solution Overview

Problem

Conventional autonomous transport vehicles in automated storage and retrieval systems face issues with wheel slip and odometry/localization challenges due to fixed wheel configurations, which can cause vibrations and inaccuracies in positioning, especially on uneven surfaces, leading to inefficiencies in order fulfillment and reduced storage density.

Innovation Solution

The autonomous transport vehicle employs a fully independent suspension system and traction control system to maintain a steady state contact patch between wheels and the rolling surface, minimizing wheel slip to less than 1° and ensuring accurate odometry, thereby enhancing localization and reducing vibrations, allowing for simultaneous case unit manipulation during traversal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If fixed wheel configuration is used, then device complexity is reduced, but wheel slip and localization precision deteriorate on uneven surfaces

Engineering Contradiction:

Improvewheel configurationVSAvoidodometry/localization accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies dynamics by making the wheel configuration adaptable rather than fixed. The suspension system allows wheels to dynamically adjust their position and orientation in response to surface variations, enabling the vehicle to maintain stable contact and accurate odometry on uneven surfaces while managing complexity through controlled adaptability

Inventive Principle:

Principle #15Dynamics

2Device complexity

If direct drive motors are used, then power transmission is simplified, but wheel slip increases causing localization errors

Engineering Contradiction:

Improvedrive systemVSAvoidtraction stability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent implements feedback through a control system that continuously monitors wheel slip conditions and adjusts motor torque accordingly. This feedback mechanism detects traction loss and modulates power delivery to prevent excessive wheel slip, maintaining reliable traction while working with the direct drive configuration

Inventive Principle:

Principle #23Feedback

3Adaptability or versatility

If vehicle traverses uneven surfaces, then adaptability to terrain is improved, but vibrations increase causing case unit movement

Engineering Contradiction:

Improveterrain handling capabilityVSAvoidvibrations

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies beforehand cushioning through a suspension system designed to absorb and dampen vibrations before they can transmit to the vehicle body and cargo. The suspension components are pre-configured to counteract expected vibrations from uneven surfaces, protecting case units from movement while maintaining terrain adaptability

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

4Adaptability or versatility

If wheel slip is allowed to occur, then traction control flexibility is improved, but odometry accuracy deteriorates

Engineering Contradiction:

Improvetraction control responseVSAvoidpositioning accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent uses feedback control to continuously monitor wheel rotation and surface conditions, adjusting motor torque in real-time to minimize wheel slip. This feedback mechanism maintains positioning accuracy by preventing excessive slip while preserving the flexibility to adapt traction control to varying surface conditions

Inventive Principle:

Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system provides superior localization and takt times for order fulfillment, reduces vibrations to prevent case unit movement, and increases vertical storage density by maintaining a constant ride height, thus improving the efficiency and accuracy of autonomous transport vehicles.

Implementation Method 1

The independent suspension system and traction control system synergistically provide a dynamic response of the autonomous transport vehicle in transit that minimizes wheel slip

Methodology Applied

Scientific EffectVibration damping: Damping

Implementation Method 2

maintain a substantially steady state contact patch between wheels and a rolling surface over which the wheels roll

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS20260091962A1Autonomous transport vehicle with synergistic vehicle dynamic response

Publication Date: 2026.04.02 SYMBOTIC LLC

AI summary

An autonomous transport robot for transporting a payload, autonomous transport robot including, frame with integral payload support that has a payload seat surface defining a payload datum position that determines predetermined payload position relative to autonomous transport robot, transfer arm connected to the frame and configured for autonomous transfer of payload to and from the frame, one caster wheel mounted to frame, drive section with a pair of traction drive wheels astride the drive section, drive section being connected to the frame, wherein the one caster wheel and one traction drive wheel of the pair of traction drive wheels roll, on a rolling surface effecting autonomous transport robot traversal over the rolling surface, each having a fully independent suspension, and are disposed on the frame astride the integral payload support so that the payload seat surface at the payload datum position is disposed at minimum distance above the rolling surface.