Servo Drive Friction Compensation Using Error-Based Parameter Identification
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Solution Overview
Problem
Current methods for determining compensation parameters to address friction-related disturbances in servo-driven machine tools are inefficient, requiring experienced technicians and lengthy commissioning times, as they assume constant friction and rely on manual parameter adjustment through trial-and-error approaches.
Innovation Solution
A method involving the use of test parameter sets and mathematical models to generate compensation signals, where a servo drive control device performs test processes to determine error signals, and replacement models or transmission behavior models are used to optimize compensation parameters, reducing the need for real measurements and speeding up the process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual parameter adjustment through trial-and-error is used, then friction compensation can be achieved, but commissioning time becomes excessively long and requires experienced technicians
Solution Approach 1:
The system automatically determines compensation parameters by analyzing measured friction data and generating optimized parameter sets without requiring manual trial-and-error adjustment by technicians. The control device performs self-configuration based on measured operating characteristics
Solution Approach 2:
The manual mechanical adjustment process is replaced by an automated computational system that uses mathematical models and algorithms to determine optimal compensation parameters, substituting human expertise with systematic automated analysis
2Ease of manufacture
If friction is assumed constant throughout machine life, then parameter determination is simplified, but the system cannot adapt to friction changes due to wear-in of guide rails
Solution Approach 1:
The system transitions from static constant friction assumptions to dynamic friction modeling that captures time-varying friction characteristics. The compensation parameters are updated based on measured friction behavior at different operating points and machine states
Solution Approach 2:
The system determines compensation parameters for multiple acceleration levels and operating conditions rather than a single constant parameter set. Parameters are adapted to reflect changing friction conditions through automated measurement and analysis
3Manufacturing precision
If a large number of parameter sets are defined for different acceleration levels and reversal points, then compensation quality is improved, but the complexity of parameterization increases significantly
Solution Approach 1:
The system segments the friction compensation problem into distinct operating conditions (reversal points, acceleration levels) and determines parameters for each segment based on measured characteristics rather than requiring comprehensive manual parameterization
Solution Approach 2:
The system uses measured following error and friction behavior as feedback to automatically determine and optimize compensation parameters. The measurement results directly inform parameter selection, eliminating the need for complex manual parameterization
Data Source
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AI summary
The invention relates to a method for determining compensation parameters (P1*, P2*), the compensation parameters (P1*, P2*) defining a compensation signal (K1*, K2*), the compensation signal (K1*, K2*) being intended to compensate for at least one disturbance, the at least one disturbance occurring during operation of a control target (MOT), the control target (MOT) being controlled during operation by a servo drive control device (SRE), the servo drive control device (SRE) being designed to generate the compensation signal (K1*, K2*) on the basis of the compensation parameters (P1*, P2*) when the at least one disturbance occurs in order to reduce a subsequent fault that can be attributed to the disturbance, and a first test parameter set (P1) being provided. In said method: the servo drive control device (SRE) is made to perform an operating process in which the at least one disturbance occurs, the servo drive control device (SRE) generating a first test compensation signal (K1) based on the first test parameter set (P1) when performing the operating process, and receiving a first measurement signal (MS1) as feedback; a first error signal (eX(t)) is determined from the first measurement signal (MS1); the compensation parameters (P1*) are determined by means of a substitution model (EM), said substitition model (EM) mapping error signals to compensation signals, and using the first error signal (eX(t)).