Sensorless Actuator Control via Velocity Extraction
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Solution Overview
Problem
Existing control systems for machines and transmissions are complex, costly, and slow due to the need for multiple sensors to manage velocity and moment, making it difficult to detect and correct malfunctions and dynamic changes, especially when sensors cannot be placed on the transmission shaft.
Innovation Solution
A control system using a single velocity sensor on the machine shaft, with a calibration process to calculate and predict moment and velocity, eliminating the need for dedicated sensors on the transmission shaft and simplifying the control loop.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple sensors are used to control moment and velocity at the transmission shaft, then control precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the velocity sensing function from the transmission shaft location and relocates it to the machine shaft, eliminating the need for sensors on the transmission shaft. This extraction reduces device complexity while maintaining control precision through mathematical modeling of the transmission system.
Solution Approach 2:
The patent introduces a mathematical model of the transmission system as an intermediary that translates machine shaft measurements into transmission shaft control parameters. This mediator enables precise control without direct sensing at the transmission shaft, reducing sensor requirements while maintaining control accuracy.
2Measurement precision
If multiple sensors are positioned on the transmission shaft, then control accuracy is improved, but response time decreases due to system complexity
Solution Approach 1:
By extracting the velocity sensor from the transmission shaft and placing it on the machine shaft, the patent reduces the number of sensors and simplifies the control loop, thereby improving response time while maintaining control accuracy through the transmission model.
Solution Approach 2:
The patent performs preliminary calibration to establish the mathematical model of the transmission system before operation. This preliminary action enables real-time accurate control without requiring complex real-time calculations, thus improving response time.
3Measurement precision
If sensors are placed on the transmission shaft, then direct measurement of transmission parameters is improved, but ease of operation decreases when placement is not feasible
Solution Approach 1:
The patent extracts the velocity measurement function from the transmission shaft and relocates it to the machine shaft, making the system easier to operate when transmission shaft access is limited. The mathematical model compensates for the indirect measurement, maintaining accuracy.
Solution Approach 2:
The patent creates a virtual copy of the transmission shaft velocity signal through mathematical modeling based on machine shaft measurements. This copied signal enables control without direct physical sensing at the transmission shaft, improving ease of operation.
4Reliability
If multiple sensors and control loops are implemented, then control capability is improved, but ease of repair decreases due to system complexity
Solution Approach 1:
By extracting unnecessary sensors from the transmission shaft and using only the machine shaft velocity sensor combined with the transmission model, the patent simplifies the system, making it easier to diagnose and repair malfunctions while maintaining control capability.
Solution Approach 2:
The mathematical model of the transmission system enables the control system to self-diagnose and adapt to changes or malfunctions by comparing expected versus actual behavior, reducing the need for complex sensor arrays and improving ease of repair.
Data Source
AI summary
An actuator having a two-parameter energy converter is coupled to a transducer and is driven by a controller. Prior to assembly and operation of the actuator, a calibration procedure is performed. The calibration procedure, together with the unique controller, enables accurate control of the output parameters of the actuator. In one example, the parameters are rate and force, and the calibration and controller enable accurate control of the rate and force at the output of the actuator by measuring only the rate at the output of the energy converter. Consequently, no sensors are needed at the output of the actuator, i.e., at the output of the transducer, where the load is applied.