Resolver Drive Signal Generation Using PWM Synchronization
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Solution Overview
Problem
Resolver sensors used in motor systems face imprecision and inaccuracy due to non-ideal drive signals resulting from signal loss and distortion, particularly in applications requiring precise position control, where a distorted drive signal can introduce errors and affect the output values.
Innovation Solution
A method and apparatus that generate an ideal sine waveform drive signal by counting time associated with incoming square wave signals, delaying the generation of the drive signal by one cycle of the square wave signal, ensuring a 50% duty ratio and preventing distortion, using a counter to synchronize the drive signal with the square wave signal, and allowing adjustment of the signal magnitude.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a drive signal is generated using conventional filtering methods, then the signal processing is simple, but the signal distortion and loss occur leading to imprecise position control
Solution Approach 1:
The patent replaces conventional analog filtering methods with a digital signal generation approach using a microcontroller. The microcontroller generates a square wave signal and uses PWM (Pulse Width Modulation) to create the sinusoidal drive signal, eliminating the need for complex analog filters and reducing signal distortion while improving position control precision
Solution Approach 2:
The patent changes the generation method of the drive signal from analog filtering to digital PWM modulation. By adjusting the duty cycle of the PWM signal according to a sinusoidal pattern, the system generates a clean sinusoidal drive signal without signal loss or distortion, thereby improving measurement precision
2Reliability
If the drive signal frequency is not synchronized with the square wave signal, then the signal generation is flexible, but signal distortion occurs and duty ratio cannot be guaranteed at 50%
Solution Approach 1:
The patent implements a synchronization mechanism where the microcontroller monitors the square wave signal frequency and adjusts the PWM generation accordingly. This feedback loop ensures the drive signal remains synchronized with the square wave, maintaining 50% duty ratio and preventing signal distortion, thereby improving signal quality reliability
Solution Approach 2:
The patent uses periodic PWM signaling synchronized with the square wave period. By generating the sinusoidal drive signal through periodic PWM pulses that match the square wave frequency, the system ensures consistent 50% duty ratio and eliminates distortion without requiring complex continuous adjustment mechanisms
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 ensures high-quality sine wave generation, prevents signal distortion, and allows for precise control of the drive signal frequency, enhancing the accuracy and reliability of resolver sensors in motor systems.
Implementation Method 1
The resolver is an analog angle detection sensor that converts a mechanical angular displacement of a motor into an electrical signal using an electromagnetic induction phenomenon
Data Source
AI summary
A method and apparatus for generating a drive signal for driving a resolver sensor are provided. The method and apparatus implement a drive signal to be input to a resolver sensor. The method and apparatus perform counting in association with an incoming square wave signal and implement a drive signal after confirming that a specific point corresponding to a preset condition of the incoming square wave signal arrives.