Motor Control Device Using Bit-Shift Circuits for Rotation Angle Correction
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Solution Overview
Problem
Motor control devices for tri-alternate-current brush-less motors face accuracy issues due to rotor rotation during processing time, leading to reduced throughput as additional steps are required to correct the rotation angle, affecting the precision of driving voltage control.
Innovation Solution
A motor control device with a rotation-angle correcting unit that uses bit-shift circuits to divide the angular speed by powers of 2 and subtract output values to determine a correction amount, allowing for accurate correction of the rotation angle, thereby enhancing processing throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a correction step is added to correct the rotation angle by calculating the correction amount corresponding to the processing time, then the accuracy of motor control is improved, but the throughput of the control process is reduced
Solution Approach 1:
The patent changes the computational parameters from general floating-point arithmetic to fixed-point arithmetic with bit-shift operations. By representing the correction coefficient as a fixed-point number and using bit-shift operations instead of multiplication, the system achieves accurate rotation angle correction while maintaining high processing throughput suitable for real-time motor control.
Solution Approach 2:
The patent replaces complex computational mechanisms with simpler electronic circuit operations. The correction amount calculation is implemented using bit-shift circuits and adder circuits instead of general-purpose processors performing floating-point arithmetic, thereby achieving both accuracy and high-speed processing suitable for motor control applications.
2Adaptability or versatility
If general computational methods are used to calculate the correction amount, then flexibility in calculation is improved, but the processing time increases
Solution Approach 1:
The patent replaces software-based general computation with hardware-based specialized circuits. Bit-shift circuits and adder circuits are used to perform the correction amount calculation in parallel, achieving deterministic fast execution while maintaining the ability to adapt to different motor control requirements through configurable circuit parameters.
Solution Approach 2:
The patent segments the correction amount calculation into independent bit-shift operations for each bit of the angular speed. This allows parallel processing of multiple bits simultaneously through multiple bit-shift circuits, significantly reducing processing time while maintaining calculation flexibility through configurable shift amounts.
Data Source
AI summary
A motor control device determines a rotation angle and an angular speed of a motor, and has: a correcting unit including N number (N is an positive integer equal to or more than 2) of bit-shift circuits, which divide the angular speed by powers of 2 by bit shift, and a circuit, which subtracts output values of the second to Nth bit-shift circuits from an output value of the first bit-shift circuit to determine a correction amount for the rotation angle and correct the rotation angle by the correction amount; so as to determine two-phase direct voltages to obtain a target torque from the three-phase alternate currents passing through the motor according to the angular speed, and convert the two-phase direct voltages into the three-phase alternate voltages according to the sine, cosine of the corrected rotation angle.