Sensorless Drive Machine State Estimation for Rotor and Load Torque Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrical drive machines for motor vehicles rely on hardware sensors for rotor position and speed detection, which are costly, space-consuming, and prone to errors in load torque calculation due to the lack of actual load torque as a starting point for control.
Innovation Solution
A method and electronic control unit that estimates the internal state of the drive machine, including rotor speed, position, and load torque, using actual stator currents and a nonlinear adaptive observer, such as a Kalman filter, without the need for angle or rotation rate sensors, allowing for reliable control and reduced vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If hardware sensors are used to detect rotor position and speed, then measurement accuracy is improved, but device complexity, cost, and weight increase
Solution Approach 1:
The patent extracts the measurement function from physical hardware sensors and implements it through software-based estimation algorithms. The sensorless control system eliminates the need for angle and rotation rate sensors by deriving rotor position and speed information from electrical measurements and mathematical models of the drive machine.
Solution Approach 2:
The patent replaces the mechanical sensor system with an electronic/software-based estimation system. Instead of using physical sensors to directly measure rotor position and speed, the system uses electrical measurements combined with mathematical models to estimate these parameters, substituting mechanical measurement with electronic computation.
2Reliability
If hardware sensors are used for rotor position and speed detection, then control reliability is improved, but cost and weight increase
Solution Approach 1:
The patent removes the physical sensor components from the system while maintaining control reliability through software-based estimation. The sensorless control architecture extracts position and speed information from electrical measurements without requiring additional mechanical or electronic sensor hardware.
3Device complexity
If load torque is computed only on the basis of vehicle parameters without actual load torque measurement, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent implements feedback by using the estimated load torque as a starting point for control, which is then refined through comparison with actual electrical measurements. The control system continuously adjusts the load torque estimation based on feedback from the drive machine's electrical behavior, improving accuracy while maintaining simplicity.
4Device complexity
If sensorless control is implemented, then device complexity and cost are reduced, but measurement precision and control reliability deteriorate
Solution Approach 1:
The patent changes the parameters used for control by estimating internal state variables (position, speed, load torque) from electrical measurements rather than directly measuring them. The estimation algorithm transforms measurable electrical quantities into accurate estimates of mechanical parameters through mathematical relationships and system models.
Data Source
AI summary
Methods, apparatuses, and systems are provided for controlling an electrical drive machine. Actuator stator currents of the electrical drive machine are measured. A manifestation of an internal state of the electrical drive machine are estimated based on the measured actuator stator currents. A quality criterion is ascertained for the estimated manifestation of the internal state of the electrical drive machine. The estimated manifestation is forwarded if the quality criterion is satisfied.