MDPS Motor Synchronization Using Current Pulses
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Solution Overview
Problem
Conventional methods for synchronizing the rotational position of a Motor Driven Power Steering (MDPS) motor with a motor position sensor require separate driving and measuring devices, increasing costs and introducing errors that degrade control performance.
Innovation Solution
A method and apparatus that aligns the MDPS motor rotor using preset three-phase current pulses, detects the actual rotational position, determines zero and reference positions, calculates an offset, and applies hysteresis compensation to correct the zero point rotational position, eliminating the need for separate measuring devices and reducing errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate driving devices and measuring devices are used for motor synchronization, then measurement and control can be performed, but manufacturing cost increases and manufacturing time extends
Solution Approach 1:
The patent merges the driving function and measurement function into a single integrated system. The controller simultaneously performs motor driving control and rotational position measurement without requiring separate driving devices and measuring devices, thereby reducing device complexity while maintaining measurement precision
Solution Approach 2:
The controller is designed to perform multiple functions: it both drives the motor through commutation control and measures the rotational position by detecting hall sensor output pulses. This multi-functionality eliminates the need for dedicated separate measuring devices, reducing overall system complexity
2Measurement precision
If separate driving devices and measuring devices are used for motor synchronization, then measurement can be performed, but manufacturing time increases due to separation and reassembly operations
Solution Approach 1:
By integrating the measurement function within the existing controller that also performs driving control, the patent eliminates the need for separate assembly and disassembly of measuring devices during manufacturing, thereby improving manufacturing productivity
Solution Approach 2:
The controller performs self-measurement of the rotational position using its own internal resources (hall sensor detection capability) without requiring external measuring devices, simplifying the manufacturing process and improving productivity
3Measurement precision
If conventional synchronization method is used with separate measuring devices, then rotational position can be measured, but measurement errors occur that degrade control performance
Solution Approach 1:
The controller uses its own internal hall sensor detection capability to measure rotational position, eliminating measurement errors that occur when separate external measuring devices are used. This self-service approach ensures higher reliability of control performance
Solution Approach 2:
The controller continuously monitors the hall sensor output pulses and uses this feedback information to accurately determine commutation timing and rotational position, improving both measurement precision and control reliability through real-time feedback
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces manufacturing time and costs while improving motor control performance by accurately synchronizing the MDPS motor and motor position sensor, minimizing measurement errors and enhancing operational efficiency.
Implementation Method 1
In general, a hall sensor is used to detect the position of the rotor, the hall sensor having a potential difference that is changed according to a change of magnetic flux
Implementation Method 2
a motor position sensor for detecting the position of the rotor
Data Source
AI summary
A method for synchronizing an MDPS motor and a motor position sensor may include: sequentially aligning, by a controller, a rotor of the MDPS motor by sequentially applying preset three-phase current pulses to the MDPS motor, the three-phase current pulses corresponding to one electrical-angle cycle of the rotor of the MDPS motor, and detecting an actual rotational position of the aligned rotor through the motor position sensor; determining a zero point rotational position of the rotor based on the actual rotational position; determining a reference rotational position of the rotor based on the actual rotational position and the number of pole pairs in the MDPS motor, and determining an offset rotational position of the rotor based on the actual rotational position and the reference rotational position; and correcting the zero point rotational position by adding the offset rotational position to the zero point rotational position.