Motor-Based Collision Detection for Self-Propelled Equipment

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Solution Overview

Problem

Conventional self-propelled apparatuses, such as intelligent mowers, require additional housing and increased production costs for collision detection, which is inefficient and costly.

Innovation Solution

A collision detection method that utilizes real-time monitoring of the self-propelled electric motor's current and rotational speed, along with acceleration data, to determine collisions without the need for additional devices, adjusting thresholds dynamically based on acceleration changes to enhance accuracy and applicability across various tools and conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a double-layer housing structure with Hall sensor is used for collision detection, then collision detection capability is achieved, but production cost and apparatus volume increase

Engineering Contradiction:
Improvecollision detection capabilityVSAvoidhousing structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the collision detection function from the mechanical housing structure and relocates it to the control system through software algorithms. By monitoring motor current and rotational speed changes, the system detects collisions without requiring physical sensors or complex housing structures, thereby eliminating additional hardware components while maintaining detection capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical Hall sensor-based detection system with an electrical/software-based detection method. By analyzing electrical parameters (current and rotational speed) of the existing motor, the system achieves collision detection without mechanical sensors, reducing both hardware complexity and production costs

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

2Measurement precision

If additional housing and Hall sensor are added for collision detection, then collision detection accuracy is improved, but production cost increases

Engineering Contradiction:
Improvecollision detection accuracyVSAvoidproduction cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent enables the existing motor to serve dual purposes: both driving the apparatus and providing collision detection data. By monitoring the motor's own electrical parameters (current and speed), the system achieves self-diagnosis capability without requiring external sensors, thereby maintaining detection accuracy while eliminating additional component costs

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent makes the existing motor multi-functional by using it both for propulsion and for collision detection. The motor's electrical parameters serve dual purposes, eliminating the need for dedicated sensors and reducing overall system cost while maintaining detection functionality

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

3Ease of operation

If fixed thresholds are used for collision detection, then detection simplicity is maintained, but detection accuracy under varying conditions deteriorates

Engineering Contradiction:
Improvedetection simplicityVSAvoiddetection accuracy under varying conditions
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent transitions from static fixed thresholds to dynamic adaptive thresholds that automatically adjust based on real-time operating conditions. By continuously monitoring motor current and rotational speed changes, the system adapts threshold values to match varying working conditions, maintaining high detection accuracy across different scenarios while preserving operational simplicity

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4279226B1Self-propelled device and collision detection method thereof
Publication Date: 2025.03.26 NANJING CHERVON IND
  • EP4279226B1 patent drawingFigure 1
  • EP4279226B1 patent drawingFigure 2A~2B
  • EP4279226B1 patent drawingFigure 3A~3B

AI summary

Provided is a collision detection method of a self-propelled apparatus. The self-propelled apparatus includes a self-propelled electric motor for driving wheels to rotate. The collision detection method includes: detecting a current of the self-propelled electric motor in real time and calculating a change rate of the current of the self-propelled electric motor; detecting a rotational speed of the self-propelled electric motor in real time and calculating a change rate of the rotational speed of the self-propelled electric motor; and determining, according to at least the change rate of the current and the change rate of the rotational speed, whether the self-propelled apparatus collides.