Time-of-flight localization for robotic safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Industrial robots operating in shared workspaces with humans pose a risk of injury due to unintended collisions, as existing safety systems are inadequate in preventing robotic unit movement when a person is nearby.
Innovation Solution
A time-of-flight (ToF) position monitoring system using reference radios and portable radios to determine a bounded position area around a person, inhibiting robotic unit movement when it approaches within a predetermined distance to ensure safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a person and robotic unit operate in proximity to each other, then productivity is improved through shared workspace operation, but safety deteriorates due to risk of inadvertent injury from robotic movement
Solution Approach 1:
The system performs preliminary detection of human presence in the workspace before allowing robotic units to operate. The safety system continuously monitors the workspace for humans and preemptively prevents robotic movement when a human is detected, eliminating the harmful effect before it can occur.
Solution Approach 2:
An intermediary safety system is introduced between the robotic unit and the human worker. This safety system acts as a mediator that detects human presence and controls robotic unit operation, allowing both productivity and safety to be maintained through coordinated control.
2Object-affected harmful factors
If safety systems inhibit robotic unit movement when a person is nearby, then safety is improved, but productivity deteriorates due to movement restrictions
Solution Approach 1:
The safety system dynamically adjusts robotic unit operation based on real-time human presence detection. When no human is detected, the robotic unit operates freely for maximum productivity. When a human is detected, the system dynamically switches to inhibition mode to ensure safety, and returns to normal operation when the human leaves the area.
Solution Approach 2:
The system changes the operational parameters of the robotic unit based on human presence. The control system modifies movement parameters, speed, and operational state according to whether a human is detected in the workspace, allowing optimal balance between safety and productivity under different conditions.
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 effectively prevents potential injuries by ensuring robotic units cease movement when in proximity to humans, creating a safer working environment by accurately determining the presence of humans through RF signal measurements and constructing bounded areas for safe operation.
Implementation Method 1
measures round-trip flight times of radio frequency (RF) signals between a person and each of multiple reference locations
Implementation Method 2
The signal flight time is then converted to a distance, based on the known propagation speed of electromagnetic waves
Data Source
AI summary
Robotic units may operate in a workspace that is shared with human workers. In order to safeguard the workers, operation of a robotic unit may be inhibited when a worker is near the robotic unit. In order to determine the position of the worker and thereby determine the proximity of the worker and the robotic unit, a time-of-flight measurement is performed to determine the distance of the worker from each of multiple reference locations within or about the workspace. A circular bounding area is defined around each reference location based on the determined distances. A bounded position area is identified as the intersection of the circular bounding areas. The worker is then indicated as being within the bounded position area.