Multi-Motor Torque Control for Mass-Based Gain and Acceleration Limits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing drivers face challenges in maintaining precise control over the position and torque of units, such as print heads, due to variations in mass distribution and current limitations, leading to potential overcurrent demands and non-linear motor behaviors.
Innovation Solution
A torque control device and method that calculates the mass of a unit supported by multiple motors based on output voltage, adjusts motor gains based on mass comparisons, and limits acceleration to prevent overcurrent and maintain horizontal alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If motor gains are adjusted based on mass variations, then control precision is improved, but control complexity increases
Solution Approach 1:
The system performs preliminary mass measurement by applying a known test voltage to the motors and measuring the resulting position change of the unit. Based on this preliminary measurement, the control device calculates the actual mass and pre-adjusts the motor gains before normal operation begins. This preliminary action eliminates the need for continuous complex adjustments during operation.
Solution Approach 2:
The control device automatically performs mass measurement and gain adjustment without requiring external intervention or complex manual calibration procedures. The system self-calibrates by using its own motors to move the unit and measuring the resulting position, then automatically calculates and applies the appropriate gain values based on the measured mass.
2Reliability
If acceleration is limited to prevent overcurrent, then motor reliability is improved, but positioning speed decreases
Solution Approach 1:
The system dynamically adjusts the acceleration limits based on the actual mass of the unit. After measuring the mass through the preliminary motor operation, the control device calculates appropriate acceleration limits that are tailored to the specific load conditions. This dynamic adjustment allows the system to operate at higher speeds when the load is light while preventing overcurrent when the load is heavy, optimizing both speed and reliability.
Solution Approach 2:
The control device changes the acceleration parameter based on the measured mass conditions. By calculating the actual mass from the preliminary motor operation results, the system adjusts the acceleration parameter to match the current load, thereby preventing overcurrent conditions while maximizing positioning speed for each specific operating condition.
3Measurement precision
If mass measurement is performed through motor operation, then measurement accuracy is improved, but energy consumption increases
Solution Approach 1:
The system performs a partial motor operation at reduced power levels to measure mass, rather than operating at full capacity. The test voltage applied during mass measurement is sufficient to move the unit and enable accurate measurement but is kept minimal to reduce energy consumption. This partial action provides adequate measurement data while consuming significantly less energy than full-power operation.
Data Source
AI summary
A torque control device includes circuitry. The circuitry is configured to output voltage to each of multiple motors to move a unit, calculate mass of the unit supported by the multiple motors based on the voltage output to each of the multiple motors, and control the torques of the multiple motors based on the mass of the unit calculated.