Dynamic Preload Torque Control for Backlash Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motor control systems using two motors to drive a single driven member struggle to effectively suppress backlash during acceleration and deceleration due to constant preload torque values that do not adjust with motor acceleration, leading to inadequate torque distribution between the main and sub motors.
Innovation Solution
A motor control apparatus that generates dynamic preload torque values for each motor based on their respective accelerations, ensuring the forces applied to the drive shafts of both motors are opposite and adjusted according to changing acceleration demands, thereby producing output torques greater than required during acceleration/deceleration to effectively suppress backlash.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If constant preload torque values are used for both motors, then the control system is simple, but backlash cannot be suppressed during motor acceleration and deceleration
Solution Approach 1:
The preload torque values for both motors are made dynamic by making them dependent on the acceleration of their respective motors. The control apparatus calculates acceleration based on changes in rotational speed and adjusts the preload torque values accordingly, allowing the system to adapt to varying operational conditions while maintaining backlash suppression capability.
Solution Approach 2:
The preload torque values are changed as parameters based on motor acceleration conditions. When acceleration exceeds a predetermined threshold, the control apparatus adjusts the preload torque values to ensure they are sufficient to suppress backlash, thereby optimizing performance under different operational states without requiring a completely complex control architecture.
2Reliability
If preload torque values are increased to suppress backlash during acceleration, then backlash suppression improves, but torque distribution between motors becomes unbalanced
Solution Approach 1:
Each motor is assigned its own preload torque value that is independently adjusted based on its specific acceleration conditions. The control apparatus calculates acceleration for each motor separately and determines appropriate preload torque values for each, allowing localized optimization of backlash suppression for each motor while maintaining overall system balance.
Data Source
AI summary
A preload torque value generating unit (22m) generates a preload torque value (Tpm) as a function of the acceleration (am) of a main motor (6m), the preload torque value (Tpm) being a torque value that is appended in advance to a torque command value (Tm) so that the direction of force applied to the main motor (6m) and the direction of force applied to a sub motor (6s) will become opposite to each other. A preload torque value generating unit (22s) generates a preload torque value (Tps) as a function of the acceleration (as) of the sub motor (6s), the preload torque value (Tps) being a torque value that is appended in advance to a torque command value (Ts) so that the direction of force applied to the main motor (6m) and the direction of force applied to the sub motor (6s) will become opposite to each other.