Resolver Offset Compensation in Hybrid Vehicle Motors
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Solution Overview
Problem
Existing methods for compensating resolver offset errors in hybrid vehicles require manual operation with oscilloscopes, increasing time and variability based on operator skill, affecting drivability and efficiency.
Innovation Solution
A control method that calculates the resolver offset value by confirming zero motor speed and torque, converging motor currents and voltages to predetermined ranges, allowing for automatic offset determination during vehicle operation without affecting drivability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual operation with oscilloscope is used to compensate resolver offset, then offset compensation can be performed, but time consumption and operator skill variability increase
Solution Approach 1:
The system automatically measures and compensates resolver offset errors using its own control unit and sensors during normal vehicle operation. The control unit monitors motor current, voltage, and speed to detect zero-torque conditions, then automatically calculates and applies offset compensation without requiring external measurement instruments or manual operator intervention.
Solution Approach 2:
The patent replaces the manual mechanical measurement process (using oscilloscope and physical waveform analysis) with an electronic automated measurement system. The control unit electronically monitors motor parameters and automatically calculates offset values, substituting the manual mechanical measurement approach with an electronic self-measurement system that eliminates time consumption and operator skill variability.
2Measurement precision
If manual offset compensation is performed, then resolver error can be corrected, but all vehicles must be compensated individually increasing work amount
Solution Approach 1:
Each vehicle's control unit independently and automatically performs offset compensation during its own operation. The system uses the vehicle's existing sensors and control infrastructure to self-measure and self-correct resolver offsets, eliminating the need for individual manual compensation of each vehicle while maintaining high accuracy.
Solution Approach 2:
The system performs offset compensation automatically during normal vehicle operation at zero-torque conditions, preparing and applying corrections in advance before they are needed for precise motor control. This preliminary automatic compensation ensures accuracy is achieved without requiring subsequent manual adjustments.
3Ease of operation
If resolver offset is not compensated, then system operation is simple, but motor position detection accuracy deteriorates causing abnormal operation
Solution Approach 1:
The control unit automatically monitors motor operation conditions and performs offset compensation without requiring external intervention or complex procedures. The system uses its own built-in sensors and processing capabilities to self-correct resolver offsets, maintaining both operational simplicity and detection accuracy through automated self-service compensation.
Solution Approach 2:
The control unit continuously monitors motor current, voltage, and speed to detect zero-torque conditions, then uses this feedback information to automatically calculate and apply offset compensation. This closed-loop feedback mechanism ensures accurate position detection is maintained while keeping the system operation simple and automated.
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
Enables accurate and automatic resolver offset compensation during vehicle operation, reducing manual intervention and variability, thereby improving drivability and efficiency.
Implementation Method 1
A resolver is a kind of transformer to transmit an excitation voltage to a first side winding (input side), and if an axis is rotated, a magnetic coupling coefficient is transformed and a voltage that varies the amplitude of a carrier is generated in a second side winding (output).
Implementation Method 2
The winding is arranged such that the voltage varies along sine and cosine curves based on the rotation angle. Accordingly, the rotation angle of the resolver can be detected by reading the carrier amplitude of the sine output and the cosine output.
Data Source
AI summary
A control method of a vehicle having a motor according to an exemplary embodiment of the present invention can include confirming that a speed of the motor is not 0 and an output torque thereof is 0 in a condition that the vehicle is being operated, confirming that a voltage of the motor converges to a regular value, and accumulating control data for the motor and processing the control data to calculate an offset value of a resolver. Accordingly, the control method of a vehicle effectively determines whether the offset of the resolver is to be compensated without affecting the drivability of the vehicle.