Robotic Peg-in-Hole Insertion for Unknown Tilt Alignment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional industrial robots lack adaptivity and flexibility to perform peg-in-hole tasks with components of unknown tilt, requiring intensive human labor for programming due to varying manufacturing conditions.

Innovation Solution

A robotic system employing force sensors, a control system, and machine learning techniques to apply forces, normalize time-series data, create a time-series prediction model, and calculate a matching ratio to determine optimal insertion strategies for components with unknown tilt.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional industrial robots are used for peg-in-hole tasks, then high repeatability is achieved, but adaptability and flexibility are lacking due to inability to handle components with unknown tilt

Engineering Contradiction:
ImproverepeatabilityVSAvoidadaptability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The robotic system employs force sensors to detect contact forces during insertion and uses machine learning models to process this feedback information. The system continuously monitors force magnitudes and directions, compares them against predicted patterns, and adjusts the insertion trajectory in real-time to accommodate components with unknown tilt, thereby maintaining both repeatability and adaptability

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The machine learning model enables the robotic system to autonomously determine the optimal insertion trajectory without requiring pre-programming or manual intervention for each component variation. The system self-adjusts by processing force sensor data and selecting trajectories from the database based on real-time conditions, eliminating the need for intensive human programming while handling manufacturing variations

Inventive Principle:
Principle #25Self-service

2Adaptability or versatility

If intensive human programming is applied to handle manufacturing variations, then adaptability is improved, but productivity and production cycle time are reduced

Engineering Contradiction:
ImproveadaptabilityVSAvoidproduction cycle time
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The system pre-establishes a database of insertion trajectories through offline machine learning training before actual production. During manufacturing, the system rapidly queries and selects appropriate pre-computed trajectories based on real-time force sensor feedback, avoiding the need for time-consuming online programming or adjustment while maintaining high adaptability to component variations

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces manual programming and mechanical adjustment processes with an automated machine learning-based decision system. The control system automatically processes force sensor data, determines optimal trajectories, and executes insertion operations without human intervention, significantly reducing production cycle time while maintaining adaptability to manufacturing variations

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

3Extent of automation

If force sensors and machine learning techniques are employed to handle unknown tilt, then adaptability and automation are improved, but device complexity increases

Engineering Contradiction:
ImproveautomationVSAvoidsystem complexity
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

The machine learning model serves multiple functions: it predicts contact forces, determines optimal insertion trajectories, and adapts to different component geometries. The force sensors not only detect contact forces but also provide feedback for trajectory adjustment. This multi-functionality reduces the need for separate specialized systems, managing complexity while enhancing automation

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system manages complexity by focusing on key parameters (force magnitude, force direction, trajectory selection) rather than controlling all possible degrees of freedom. The machine learning model processes force sensor data and translates it into trajectory adjustments, simplifying the control problem by parameter transformation and pattern recognition rather than complex multi-variable control

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS10953548B2Perform peg-in-hole task with unknown tilt
Publication Date: 2021.03.23 INTERNATIONAL BUSINESS MACHINE CORPORATION
  • US10953548B2 patent drawing
  • US10953548B2 patent drawing
  • US10953548B2 patent drawing

AI summary

A computer-implemented method executed by a robotic system for performing a positional search process in an assembly task is presented. The method includes applying forces to a first component to be inserted into a second component, detecting the forces applied to the first component by employing a plurality of force sensors attached to a robotic arm of the robotic system, extracting training samples corresponding to the forces applied to the first component, normalizing time-series data for each of the training samples by applying a variable transformation about a right tilt direction, creating a time-series prediction model of transformed training data, applying the variable transformation with different directions for a test sample, and calculating a matching ratio between the created time-series prediction model and the transformed test sample.