Box Opening Device Speed Control for Cardboard Handling
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Solution Overview
Problem
Existing box-opening devices face failures such as deformation or damage of cardboard boxes due to excessive force and unintentional release of grasping, especially when handling boxes of varying sizes, as the predetermined posture change speed does not account for the size variability.
Innovation Solution
A box-opening device with a control system that adjusts the angle formed by the first and fourth side surfaces based on the size of the cardboard box sheet, allowing the first arm to move at a slower speed during the initial action and faster during the main action, reducing the risk of excessive force on the box and grasping parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the arm moves at a high speed during the main action, then the productivity is improved, but the cardboard box sheet may be damaged or deformed due to excessive force
Solution Approach 1:
The unfolding action is divided into two distinct phases: an initial action phase and a main action phase. During the initial action, the arm moves at a slower speed to form a gap between overlapping side surfaces, reducing the risk of damage. During the main action, the arm moves at a higher speed to complete the unfolding. This segmentation allows the system to achieve high productivity while preventing damage by using appropriate speeds for different stages of the process.
Solution Approach 2:
Before performing the high-speed main unfolding action, the system performs a preliminary initial action at a slower speed. This preliminary action forms a gap between the overlapping side surfaces of the cardboard box sheet, preparing the structure for the subsequent high-speed unfolding. This preliminary preparation prevents damage that would occur if high speed were applied directly to the folded box.
2Object-affected harmful factors
If the arm moves at a slow speed during the initial action, then the cardboard box sheet is protected from damage, but the productivity is reduced
Solution Approach 1:
The unfolding process is segmented into two phases with different speed characteristics. The initial action phase operates at a slower speed to protect the cardboard box sheet from damage while forming necessary gaps. The main action phase operates at a higher speed to maximize productivity. This segmentation ensures that the time penalty for slow operation is minimized while still providing adequate protection during the critical initial stage.
Solution Approach 2:
The initial action is designed as a partial action that performs only the necessary preparatory function of forming gaps between side surfaces, rather than completing the entire unfolding process. This allows the system to use slow speed only for the minimum necessary duration to prevent damage, while the majority of the unfolding work is completed at higher speed in the main action phase.
3Device complexity
If the predetermined location for the initial action is fixed, then the device complexity is reduced, but the reliability decreases when handling boxes of varying sizes
Solution Approach 1:
The control system is designed to dynamically adjust the completion location of the initial action based on the size of the cardboard box sheet being processed. Rather than using a fixed predetermined location, the system calculates and adjusts the appropriate location according to the specific box dimensions. This dynamic adaptation maintains reliability across varying box sizes while keeping the control logic relatively simple through the use of basic size-based calculations.
Data Source
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AI summary
Provided is a highly reliable box-opening device being capable of suppressing failures of a box-opening action regardless of a size of a cardboard box sheet. The box-opening device unfolds a cardboard box sheet (a sheet) in which first and second side surfaces (C11, C12) and third and fourth side surfaces (C13, C14) overlap, and forms a square-tube-shaped cardboard box. The box-opening device has a suction disk (41b) to grasp the first side surface, a main arm (45a) having suction disks (42a, 42b) to grasp the fourth side surface and changing a posture while grasping the fourth side surface, and a control part to control a movement of the main arm so that an initial action, in which a gap is formed between the first and second side surfaces and the third and fourth side surfaces, and a main action that follows the initial action, are executed as an action of unfolding the sheet. The main arm moves at or slower than a predetermined speed in the initial action, and moves faster than the predetermined speed in the main action. The control part controls the main arm based on an angle (α) formed by the first side surface and the fourth side surface at completion of the initial action, which is determined according to the sheet size.