Robot Screw Gauge Alignment Using Force-Controlled Hole Inspection
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Solution Overview
Problem
Existing screw thread inspection devices face challenges in accurately aligning the limit gauge with the screw hole, potentially damaging the screw hole due to misalignment or eccentricity, and require separate devices for decision-making, which complicates the inspection process.
Innovation Solution
A control device and method that utilize a robot arm with a force detection section to accurately align and insert a screw gauge into a screw hole by performing force control perpendicular to the screw hole's axis, allowing for precise alignment and insertion without damaging the screw hole, and incorporating a determination section to make pass/fail decisions based on depth and rotation information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the limit gauge is inserted into the screw hole using a rotary motor and reciprocation device, then the inspection can be performed, but misalignment between the limit gauge and screw hole causes insertion failure
Solution Approach 1:
The patent replaces the traditional mechanical alignment system (rotary motor + reciprocation device) with a force-controlled robotic system. The robot arm uses force sensors to detect contact forces between the limit gauge and screw hole, enabling automatic alignment through force feedback rather than precise mechanical positioning. This substitution allows the system to compensate for positioning errors by adjusting based on real-time force detection.
Solution Approach 2:
The system enables the limit gauge to self-align with the screw hole through force feedback. When the gauge contacts the hole, the force sensor detects the interaction force, and the robot automatically adjusts the gauge's position and orientation to achieve proper alignment, eliminating the need for separate alignment mechanisms.
2Reliability
If the limit gauge is screwed into the screw hole, then the inspection can be performed, but eccentricity in the limit gauge or inspection device may damage or break the screw hole
Solution Approach 1:
The patent replaces the traditional torque-controlled screwing mechanism with a force-controlled robotic system. The force sensor continuously monitors the interaction force between the limit gauge and screw hole during insertion, allowing the system to detect and prevent excessive forces that could cause damage. The robot adjusts the insertion force in real-time based on sensor feedback, preventing damage even when slight eccentricity exists.
Solution Approach 2:
The system prepares for potential damage by implementing force threshold monitoring before actual damage occurs. The force sensor detects abnormal forces during the screwing process, and the control system stops the insertion before excessive force can damage the screw hole, effectively cushioning against potential harm.
3Reliability
If separate devices are used for inspection and decision-making, then the inspection process can be performed, but the device complexity increases
Solution Approach 1:
The patent merges the inspection function and decision-making function into a single integrated system. The force sensor serves dual purposes: it detects the physical interaction during inspection and provides the data basis for making pass/fail decisions. The robot control system processes the force data to determine whether the screw hole meets specifications, eliminating the need for separate decision-making devices.
Solution Approach 2:
The force sensor and robot control system perform multiple functions: they monitor insertion force, detect alignment status, determine inspection results, and control the robot's movements. This multi-functionality reduces the number of separate components needed while maintaining comprehensive inspection capabilities.
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
Enables accurate and efficient screw thread inspection by ensuring proper alignment and preventing damage to the screw hole, while eliminating the need for separate devices to make inspection decisions, thus improving the reliability and efficiency of the inspection process.
Implementation Method 1
a force detection section to detect force applied to the screw gauge
Data Source
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AI summary
A control device adapted to control a robot including a robot arm provided with a force detection section includes a control section adapted to operate the robot arm to move a screw gauge which is disposed on a tip side of the force detection section of the robot arm, used for an inspection of a screw hole, and has a screw part, to make the screw part have contact with the screw hole, and then detect force applied to the screw gauge using the force detection section to perform force control in a direction perpendicular to a direction of an axis of the screw hole based on detection information of the force detection section, and operate the robot arm to move the screw gauge.