OHT Carrier Lifting Force Control for Abnormal Lock Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing conveying systems in semiconductor fabrication face challenges in efficiently transporting workpieces while minimizing power consumption and preventing damage due to abnormal carrier locking, which can lead to damage to substrates, carriers, and load ports.
Innovation Solution
A conveying system with an overhead hoist transport (OHT) vehicle that calculates and adjusts a minimum lifting force based on carrier weight, number of workpieces, and vertical distance, and includes sensors to detect abnormal conditions, preventing damage by sending alerts and adjusting lifting forces accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional conveying systems use fixed lifting force, then simplicity of operation is maintained, but power consumption increases and damage risk occurs due to abnormal carrier locking
Solution Approach 1:
The patent implements dynamic adjustment of lifting force based on real-time detection of carrier status. The system transitions from fixed lifting force to variable lifting force that adapts to different operational conditions (normal operation vs. abnormal locking), thereby reducing power consumption while preventing damage.
Solution Approach 2:
The patent employs feedback mechanisms through sensors that detect carrier position and locking status. This feedback information is used to automatically adjust the lifting force, creating a closed-loop control system that optimizes power consumption and prevents damage without requiring complex manual intervention.
2Reliability
If lifting force is increased to prevent abnormal locking damage, then reliability improves, but substrates and workpieces may be damaged due to excessive force
Solution Approach 1:
The patent applies different lifting force levels to different operational conditions. During normal operation, a standard lifting force is used. When abnormal locking is detected, the system adjusts to a modified lifting force that is sufficient to prevent damage to the carrier and load port but controlled to avoid damaging the substrates and workpieces.
Solution Approach 2:
The lifting force is dynamically adjusted based on real-time detection of abnormal conditions. The system monitors carrier status and automatically modulates the lifting force to match the actual operational needs, preventing both under-force damage to the carrier and over-force damage to the substrates.
3Reliability
If sensors and detection systems are added to detect abnormal conditions, then damage prevention capability improves, but device complexity increases
Solution Approach 1:
The patent integrates sensors that provide feedback on carrier position and locking status. This feedback enables automatic detection of abnormal conditions and triggers appropriate responses (adjusting lifting force or alerting operators), thereby improving damage prevention capability through a relatively simple feedback loop rather than complex control systems.
Data Source
AI summary
A method for operating a conveying system is provided. An overhead hoist transport (OHT) vehicle is provided, wherein the OHT vehicle includes a gripping member configured to grip and hold a carrier, and a receiver configured to receive a signal. The signal is transmitted to the receiver of the OHT vehicle. The OHT vehicle is moved toward the carrier, and the carrier is gripped by the gripping member of the OHT vehicle. A lifting force is determined based on a weight of a carrier, a number of workpieces in the carrier, or a vertical distance between the OHT vehicle and the carrier, and the lifting force is applied to the carrier.