Robot Motor Status Control for Reliable Error Braking

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current robot error response methods, such as STOP 0 and STOP 1/2, face challenges like increased braking distance, mechanical brake dependency, and potential deviation from the path, especially when motor-active responses fail, leading to longer reaction times and reduced reliability.

Innovation Solution

A method that monitors the functionality of robot motors and selects the most appropriate error response based on their status, switching between motor-active and motor-passive responses to ensure reliable and efficient braking, using sensors and control means to manage kinematic and force variables, and adapt error reactions dynamically.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If motor-active error response (STOP 1/2) is used, then braking distance and load are reduced, but reliability decreases when motor functionality is not ensured

Engineering Contradiction:
Improvebraking distanceVSAvoiderror response reliability
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The system performs preliminary monitoring of motor functionality (torque, current, temperature) before an error response is needed. This allows the control means to pre-determine whether motor-active error responses can be reliably executed, and to pre-select the appropriate error response strategy accordingly.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors motor output variables (torque, current, temperature) and uses this feedback to dynamically assess motor functionality. Based on this real-time feedback, the control means adjusts the selection between motor-active and motor-passive error responses to maintain reliability under varying operational conditions.

Inventive Principle:
Principle #23Feedback

2Reliability

If kinematic monitoring (position-based or speed-based braking ramp monitoring) is used to detect motor failure, then motor functionality can be assessed, but reaction time increases

Engineering Contradiction:
Improvemotor functionality detectionVSAvoidreaction time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

Instead of waiting for kinematic deviations to detect motor failure, the system preliminarily monitors motor output variables (torque, current, temperature) that directly indicate motor health. This early detection approach enables faster response before kinematic errors manifest.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system replaces mechanical/kinematic monitoring (position and speed sensors) with direct motor parameter monitoring (torque, current, temperature sensors). This substitution allows for earlier and more accurate detection of motor functionality issues, reducing reaction time.

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

3Manufacturing precision

If motor-active error response is used, then braking is performed in line with the path, but the system becomes dependent on adequate motor function

Engineering Contradiction:
Improvepath complianceVSAvoiderror response adaptability
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The system dynamically adapts the error response strategy based on real-time motor functionality assessment. When motors are functional, motor-active responses (STOP 1/2) are selected for path-compliant braking. When motor functionality is compromised, the system switches to motor-passive responses (STOP 0) or alternative strategies, ensuring adaptability to varying operational conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control means changes the operational parameters of the error response based on motor functionality. It monitors motor output variables and adjusts the selected error response type (STOP 0, STOP 1, STOP 2, or other strategies) to match the current motor capability, thereby maintaining both path compliance and system adaptability.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2839934B1Method for controlling a robot
Publication Date: 2021.11.10 KUKA DEUT GMBH
  • EP2839934B1 patent drawingFigure 1~2

AI summary

An inventive method for controlling a robot (1) comprises the steps: monitoring the robot (S1); and executing (S4) a selected error response from a number of predetermined errors based on the monitoring of the robot; wherein the error response is selected (S3) based on monitoring (S2) of a functionality and/or an output variable of at least one motor (1.1) of the robot.