Hoist Speed Correction Curve for Load Chain Vibration Control
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Solution Overview
Problem
Existing hoist systems experience vibration and resonance issues due to variations in the speed of the load chain, which can be exacerbated by mechanical configurations intended to prevent vibration, leading to increased size and cost.
Innovation Solution
A hoist setting method that includes using an encoder to detect the rotation of a drive motor, applying tension to the load chain, and calculating a speed correction curve based on cyclic variations in the motor torque command value to correct the speed command for driving the drive motor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If mechanical configuration is added to prevent vibration by suppressing speed variation, then vibration suppression is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces mechanical vibration suppression configurations with a control-based solution. A speed correction curve is calculated based on cyclic variations in motor torque command value, and this curve is used to correct the speed command for the drive motor. This substitutes mechanical means with a control algorithm that processes torque variations and generates corrected speed commands, thereby suppressing vibration without adding mechanical complexity.
Solution Approach 2:
The patent utilizes feedback from the motor torque command value to generate the speed correction curve. The cyclic variations in torque are detected and fed back into the control system, which then adjusts the speed command accordingly. This feedback mechanism allows the system to automatically compensate for speed variations that cause vibration, replacing the need for additional mechanical vibration suppression components.
2Object-affected harmful factors
If mechanical configuration is added to prevent vibration, then vibration suppression is improved, but manufacturing cost increases
Solution Approach 1:
The patent replaces expensive mechanical vibration suppression components with a control algorithm. The speed correction curve calculation based on torque variations provides a software-based solution that eliminates the need for additional mechanical parts, thereby reducing manufacturing costs while maintaining vibration suppression effectiveness.
3Object-affected harmful factors
If speed correction based on torque variation is implemented, then vibration suppression is improved, but control complexity increases
Solution Approach 1:
The patent calculates the speed correction curve in advance based on the cyclic variations in motor torque command value. This pre-calculated curve is then applied to correct the speed command during operation. By performing the correction calculation beforehand and storing the results, the system reduces the real-time computational burden while maintaining effective vibration suppression.
Data Source
AI summary
This method for setting a hoist that is equipped with an encoder for detecting the rotation speed of a drive motor and that lifts and lowers an article by rotating a load sheave using a driving force of the drive motor so as to roll up and roll down a load chain, the method comprising: a drive step for driving the drive motor at a constant rotation speed while applying a tensile force to the load chain; a storage step for storing, in a storage means, positional information obtained from the encoder in the drive step and a motor torque command value for controlling the drive motor in association with said positional information; and a speed correction curve calculation step for calculating a speed correction curve for driving the drive motor on the basis of cyclical variations in the motor torque command value stored in the storage step.