Robot Bulk-Part Assembly Using Force-Guided Contact Verification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing robotic assembly methods for parts arranged loosely in containers face inefficiencies due to the need for separate robots to apply force after initial placement, as anti-collision mechanisms prevent direct assembly, leading to increased time and complexity.
Innovation Solution
A method and system utilizing multiple robots with actuated joints and gripping members, controlled by data processing means, to determine and execute trajectories while monitoring force variations to ensure safe and efficient assembly of parts, allowing simultaneous depalletizing and assembly without repositioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a robotic arm with anti-collision mechanism is used to pick up parts from bulk container, then safety is improved, but the ability to apply force for assembly is lost
Solution Approach 1:
The robot transitions from a static anti-collision mode to a dynamic controlled-contact mode. The system dynamically adjusts the control strategy based on the assembly phase: using anti-collision monitoring during approach, and switching to controlled force application during insertion, allowing the robot to adapt its behavior to different operational requirements
Solution Approach 2:
The system changes the force parameter thresholds dynamically during the assembly process. It uses a safety threshold for collision detection during approach, then transitions to an expected force variation range during actual assembly, allowing the robot to differentiate between harmful collisions and beneficial assembly forces
2Productivity
If a separate press is used to apply force for assembly, then assembly capability is improved, but device complexity and time loss increase
Solution Approach 1:
The first robot is designed to perform multiple functions: it acts as both a depalletizing robot for picking parts from bulk containers and as an assembly robot for performing peg-in-hole operations. This multi-functionality eliminates the need for a separate press or second assembly robot, reducing system complexity
Solution Approach 2:
The invention merges the depalletizing function and the assembly function into a single robotic system. The first robot simultaneously performs both tasks that were previously separated: picking parts from bulk containers and performing forceful assembly operations, consolidating multiple operations into one integrated process
3Force
If a separate press is used for assembly operations, then assembly force is improved, but loss of time increases
Solution Approach 1:
The first robot maintains continuous useful action by seamlessly transitioning from depalletizing to assembly operations without repositioning. The robot picks the part, moves it directly to the assembly position, and performs the insertion operation in a continuous workflow, eliminating idle repositioning time that would occur with separate dedicated robots
Solution Approach 2:
The system performs preliminary positioning and alignment during the approach phase before the actual forceful insertion. The robot prepares the part in the correct orientation and position during the non-forceful approach, so that when assembly force is applied, the part is already optimally positioned for immediate insertion without additional repositioning time
Data Source
Figure 1
Figure 2(a)~2(g)
Figure 3a
AI summary
The present invention relates to a method of assembling at least one first part (2a) with a second part (2b), the first part (2a) being arranged loose in a first container (3a), the method being characterized in that it comprises the implementation by data processing means (4) of steps of: (c) Determination of a first trajectory of a first robot (1a) equipped with actuated joints (12a) and a gripping member (11a), enabling the grasping of said first part (2a) in the first container (3a) with the gripping member (11a) of the first robot (1a) and then moving it until it is assembled with the second part (2b), said second part (2b) being held by a gripping member (11b) of a second robot (1b) different from the first robot (1a) in a predefined waiting position;(d) Control of the first robot (1a) so as to implement said trajectory, by estimating a force exerted on said actuated joints (12a) of the first robot (2a) as a function of the advancement of the trajectory; (e) Verification that during the trajectory: - Until contact of the first part (2a) with the second part (2b), the force exerted is less than a safety threshold; - afterwards, a variation of the force exerted conforms to an expected variation representative of the assembly of the first part (2a) with the second part (2b).