Elevator Drive System Torque Feedforward Tuning
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Solution Overview
Problem
Existing elevator drive systems require complex and time-consuming manual tuning procedures for accurate torque feedforward determination, which are prone to errors and affect ride comfort and smooth operation.
Innovation Solution
A method and elevator control unit for automatically determining feedforward control parameters through a test run, measuring motor torque, and calculating parameters such as balance, shaft efficiency, effective rope mass, and total non-changing masses to achieve precise torque control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual tuning procedures are used for torque feedforward determination, then position control accuracy can be achieved, but the process becomes complex and time-consuming
Solution Approach 1:
The system automatically determines torque feedforward parameters by having the elevator perform self-tests during normal operation. The control unit collects torque data from motor current measurements and automatically calculates feedforward values without requiring external manual intervention or specialized commissioning equipment.
Solution Approach 2:
The patent replaces manual mechanical tuning procedures with an automated electronic measurement and calculation system. Instead of manually observing traction sheave movements and adjusting parameters, the system uses motor current sensors and control unit calculations to automatically determine accurate torque feedforward values.
2Measurement precision
If manual tuning procedures are used for position control, then control accuracy can be achieved, but the process is prone to errors by installation and service personnel
Solution Approach 1:
The elevator system performs self-diagnosis and self-tuning by automatically collecting operational data and calculating optimal parameters. This eliminates human error in manual tuning while maintaining high precision through automated measurement and calculation processes executed by the control unit.
Solution Approach 2:
The system continuously monitors motor current, torque, and position data during operation, using this feedback to automatically adjust and refine torque feedforward parameters. This closed-loop approach ensures high reliability by constantly optimizing control accuracy based on actual operational conditions.
3Ease of operation
If traditional tuning methods are used, then motion control can be adjusted, but much expertise is required from installation and service personnel
Solution Approach 1:
The system eliminates the need for expert manual tuning by automatically performing all adjustment operations. The control unit executes predefined test sequences, collects data, and calculates parameters without requiring specialized knowledge or manual intervention, making the process accessible to standard installation and service personnel.
Solution Approach 2:
The system performs preliminary automated tests and measurements during initial commissioning to establish baseline parameters. This preliminary action captures all necessary data before normal operation begins, simplifying the overall tuning process and eliminating the need for complex expert adjustments during later service.
4Reliability
If torque feedforward is not determined accurately, then the speed controller can correct the torque reference, but smooth starts of the elevator ride can't be achieved
Solution Approach 1:
The system performs preliminary automated determination of torque feedforward parameters before normal operation begins. By calculating accurate feedforward values in advance based on motor current measurements and operational tests, the system ensures smooth starts without requiring continuous speed controller correction during actual elevator rides.
Solution Approach 2:
The system uses real-time feedback from motor current sensors to continuously refine torque feedforward values. This feedback mechanism ensures that the feedforward torque accurately matches actual operational requirements, enabling smooth starts while minimizing the need for reactive speed controller corrections.
Data Source
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AI summary
An elevator control unit and a method for determining at least one position control feedforward torque parameter value of an elevator, the elevator comprising a drive system for driving an electric motor and an elevator control unit for controlling the drive system. The elevator control unit comprises position control means, and the position control means comprise means for determining position control feedforward torque, which means for determining position control feedforward torque comprises parameter values which relate to the elevator and/or components of the elevator. The method comprises driving at least one elevator test run, measuring and/or determining torque of the motor during the test run, and determining based at least in part on the position control feedforward torque and/or the measured and/or determined torque of the motor during the test run at least one of the following position control feedforward torque parameter values of the elevator position control means: a parameter value relating to balance, a parameter value relating to shaft efficiency, a parameter value relating to effective rope and/or car cable mass, a parameter value relating to total non-changing masses.