Robot-Assisted Grinding Speed Control for Gentle Surface Contact
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Robot-assisted grinding devices face challenges in accurately controlling process force due to the high inertia of industrial robots, leading to difficulties in preventing scratches or grooves during surface processing, as conventional robots struggle to quickly react to force fluctuations and place the grinding machine gently on the workpiece surface.
Innovation Solution
A grinding device is developed with a motor-driven grinding tool coupled to a manipulator, where the speed of the grinding tool is initially set to a low speed for approaching the surface and increased to a higher speed upon contact detection, while a linear actuator regulates the contact force, allowing precise control of the grinding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the grinding machine is positioned by means of the manipulator to contact the surface with the grinding tool, then the position control precision is improved, but the response speed to force fluctuations deteriorates due to high inertia
Solution Approach 1:
The system is divided into two independent control functions: the manipulator handles position control with high precision, while the linear actuator handles force control with fast response. This segmentation allows each component to optimize its specific function without being constrained by the other's limitations.
Solution Approach 2:
The linear actuator serves as an intermediary between the manipulator and the grinding machine, specifically positioned between the TCP and the grinding machine to decouple position control (manipulator) from force control (linear actuator), enabling independent optimization of both control aspects.
2Productivity
If the grinding tool is operated at high speed during approach, then productivity is improved, but scratches or grooves are caused on the surface upon contact
Solution Approach 1:
The grinding process uses periodic speed variation: low speed during approach and contact establishment, then high speed during actual grinding. This periodic speed adjustment prevents surface damage during critical contact phases while maintaining high productivity during stable grinding operations.
Solution Approach 2:
The system performs preliminary gentle contact at low speed before transitioning to high-speed grinding. This preliminary action establishes stable contact without causing surface damage, preparing the system for subsequent high-productivity grinding.
3Measurement precision
If a linear actuator is arranged between the TCP and the grinding machine to control process force, then force control accuracy is improved, but device complexity increases
Solution Approach 1:
The linear actuator serves as an intermediary between the manipulator and the grinding machine, specifically positioned between the TCP and the grinding machine to decouple position control (manipulator) from force control (linear actuator), enabling independent optimization of both control aspects.
4Productivity
If the grinding wheel is already rotating when contacting the surface, then productivity is improved, but scratches or scoring occur on the workpiece surface
Solution Approach 1:
The grinding process uses periodic speed variation: low speed during approach and contact establishment, then high speed during actual grinding. This periodic speed adjustment prevents surface damage during critical contact phases while maintaining high productivity during stable grinding operations.
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention relates to a method for the automated grinding of surfaces and to a corresponding device. According to one exemplary embodiment, the method comprises the robot-assisted positioning of a grinding machine with a grinding tool, so that the grinding tool contacts the surface when the grinding machine is operated at a first rotational speed, and the detection of the contact between the grinding tool and the surface. The method further comprises, as a result of detecting the contact, the increase in the rotational speed of the grinding tool from the first rotational speed to a second rotational speed.