Work Robot Contact Detection Using Fluid Discharge Volume Change
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing work robots face challenges in securely detecting contact with humans and obstacles due to erroneous sensor detections, leading to reduced production efficiency and safety concerns, especially when sensors are embedded in cushioning materials or placed directly on robot arms, as they struggle to maintain sensitivity and accuracy across various environments and contact directions.
Innovation Solution
A work robot design featuring a robot arm with an impact buffering member and a contact detection unit comprising a soft porous member housed in a flexible material, with a fluid discharge pipe and volume change detection system to instantly and accurately detect contact and control the robot's operation, ensuring safety by discharging fluid when contact occurs and monitoring pressure changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sensor is attached to the surface of the robot arm to detect approach of a person or obstacle, then the robot can detect contact and stop operation to ensure safety, but erroneous detection occurs causing unnecessary operation restriction and reduction of working time
Solution Approach 1:
The patent applies local quality by using a soft porous member with specific material properties (softness and porosity) at the contact detection location. This localized material property enables the sensor to distinguish between genuine contact and false signals, reducing erroneous detections while maintaining safety.
Solution Approach 2:
The patent employs porous materials (soft porous member) in the contact detection unit. The porous structure allows the member to deform under contact forces while maintaining its ability to trigger detection only under sufficient force, thereby reducing false positives and improving both safety and productivity.
2Reliability
If the sensitivity and position of the sensor are set to prevent erroneous detection, then false alarms are reduced, but it becomes difficult to appropriately deal with all of various working environments
Solution Approach 1:
The patent utilizes parameter changes by making the soft porous member's detection threshold adaptable through its material properties. The softness and porosity parameters allow the sensor to automatically adjust to different working environments without requiring manual recalibration, achieving both detection accuracy and environmental adaptability.
Solution Approach 2:
The soft porous member provides dynamic detection capabilities, allowing the sensor to respond appropriately to varying contact forces and environmental conditions. This dynamic response enables the system to adapt to different working scenarios while maintaining accurate detection.
3Reliability
If a cushioning material is provided on the robot arm surface to alleviate impact, then safety is improved, but the arrangement position of contact detection sensors becomes difficult to secure
Solution Approach 1:
The patent merges the cushioning material and contact detection sensor into a single integrated unit. The soft porous member serves dual functions: providing impact cushioning and enabling contact detection. This integration eliminates the complexity of separate sensor arrangement while maintaining both safety and detection capabilities.
Solution Approach 2:
The soft porous member performs multiple functions simultaneously: it acts as cushioning material to alleviate impact and as the core sensing element for contact detection. This multi-functionality resolves the contradiction by eliminating the need for separate sensor placement while maintaining both protective and detection roles.
4Device complexity
If the sensor operates by deformation of the cushioning material, then sensor placement is enabled on cushioned surfaces, but sufficient sensitivity cannot be secured when external force acts in oblique directions
Solution Approach 1:
The soft porous member is designed with specific local quality properties (softness and porosity) that enable it to detect forces from multiple directions. This localized material property ensures sufficient detection sensitivity regardless of the direction from which external force is applied, while maintaining placement flexibility on cushioned surfaces.
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 solution enables instantaneous and reliable detection of human or obstacle contact, allowing for immediate operation restriction of the robot arm, thereby ensuring sufficient safety during cooperative work by alleviating impact and preventing pinching incidents.
Implementation Method 1
a fluid discharge pipe communicating with an inside of the housing member, the fluid discharge pipe discharging a fluid inside the housing member when the object contacts the housing member and a volume of the housing member decreases
Data Source
AI summary
A robot with an impact buffering member on the surface of a robot arm for alleviating the impact when the arm contacts an object; and a contact detection unit for detecting a contact between the robot arm and object. The unit has a soft porous member on the front surface side of the impact buffering member and softer than the member; a housing member including the soft porous member and formed of a flexible material; a fluid discharge pipe for discharging a fluid inside the housing member when the object makes contact so the volume of the housing member decreases; and a volume change detection portion for detecting a change in volume of the housing member by utilizing the discharged fluid. It is possible to secure sufficient safety in a cooperative work between a person and a robot or the like, even when the person contacts the robot arm.