Robotic Assembly Force Parameter Tuning for Tight-Tolerance Insertion
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Solution Overview
Problem
The process of programming industrial robots with force control for assembly tasks has become more complex due to the dependence on interaction forces between parts, making the selection of optimal parameters tedious and time-consuming, often requiring trial and error or offline analysis tools.
Innovation Solution
A method and system that categorize assembly processes into types like cylindrical, radial, and multi-stage insertion, specify search patterns and parameters, use Design of Experiment techniques to find optimal parameters, and verify these parameters to ensure efficient robotic assembly, utilizing a computing device and industrial robot to automate the optimization process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If force control is used for robotic assembly, then the robot can perform tight-tolerance assembly tasks, but the programming complexity increases and parameter optimization becomes time-consuming
Solution Approach 1:
The patent applies parameter changes by systematically varying force control parameters (search force, insertion force, approach speed, search speed) through Design of Experiment methodologies. This allows optimization of assembly precision while reducing programming complexity through structured parameter exploration rather than trial-and-error approaches.
Solution Approach 2:
The patent implements preliminary action by pre-defining search patterns (linear, circular, spiral, radial) and parameter ranges before actual assembly execution. This preliminary structuring of the control approach reduces programming complexity during actual operation while maintaining tight-tolerance assembly precision.
2Reliability
If trial and error or offline analysis tools are used for parameter selection, then optimal parameters can be obtained, but the process becomes tedious and time-consuming
Solution Approach 1:
The patent replaces manual trial-and-error mechanical parameter tuning with automated computational Design of Experiment systems. This substitution uses algorithmic parameter exploration and statistical analysis to automatically identify optimal parameters, significantly reducing selection time while maintaining or improving optimization reliability compared to manual methods.
3Adaptability or versatility
If the actual robot path depends on interaction forces, then flexible assembly is enabled, but the control process becomes more difficult
Solution Approach 1:
The patent segments the assembly process into distinct phases (approach, search, insertion, withdrawal) with specific force control parameters for each phase. This segmentation enables flexible adaptation to interaction forces while simplifying control by providing structured guidance for each segment, making the overall control process more manageable despite force-dependent path variations.
Solution Approach 2:
The patent introduces search patterns as intermediary control structures between the robot controller and the force-controlled end effector. These patterns act as mediators that guide the force control behavior during approach and alignment phases, enabling assembly flexibility while reducing control difficulty through standardized intermediate control logic.
Data Source
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AI summary
A method and system to optimize the parameters of a robot used in an assembly process. The assembly process is categorized based on its nature which may be cylindrical, radial and multi-stage insertion. The search pattern and search parameters are specified. The parameters are optimized and the optimized parameter set are verified and when a predetermined criteria such as assembly cycle time set and/or success rate is met the optimization process stops. When the optimization stops the verified parameters are used to cause the robot to perform the categorized assembly process. If the parameters do not meet the predetermined criteria, another round of optimization using the same or other parameters can be performed.