Throttle Valve Assembly With Cogging Torque Compensation Control
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Solution Overview
Problem
Existing DC electric motors in throttle bodies for combustion engines suffer from parasitic cogging torque, leading to inaccurate throttle control and air intake volume due to disrupted command signals, which existing feedback control methods like PID with Fourier transforms are slow and unsuitable for implementation due to processing limitations.
Innovation Solution
A throttle body with a DC electric motor and electronic control unit that calculates a compensation angle value using a correspondence table to instantaneously correct for cogging torque, reducing calculations and improving precision through a predetermined angle correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a DC electric motor with carriers and slots is used to reduce manufacturing costs, then manufacturing cost is reduced, but parasitic cogging torque is generated that disrupts control signals
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing compensation values in a lookup table during the design phase. The electronic control unit retrieves pre-computed correction values based on rotor position, eliminating the need for real-time Fourier transforms and enabling instantaneous compensation of cogging torque effects without complex calculations.
Solution Approach 2:
The patent changes the control parameter by introducing a compensation angle value that adjusts the command signal based on the rotor position. This parameter modification allows the system to counteract cogging torque by varying the motor command in real-time according to pre-stored compensation data, maintaining control accuracy despite the simplified motor structure.
2Measurement precision
If feedback control with Fourier transforms is used to counteract cogging torque, then control precision is improved, but processing time increases and computational complexity rises
Solution Approach 1:
The patent extracts the computationally intensive Fourier transform calculations from the real-time control loop and moves them to the offline design phase. By pre-computing and storing compensation values in a lookup table, the system eliminates complex real-time mathematical operations, retaining only simple table lookups and additions in the real-time control path.
Solution Approach 2:
The patent replaces expensive, computationally heavy Fourier transform operations with inexpensive lookup table accesses. The complex calculation is performed once during system initialization or calibration, and the results are reused indefinitely through simple memory retrieval, dramatically reducing real-time processing requirements.
3Reliability
If complex feedback control algorithms are implemented, then cogging torque compensation is improved, but device complexity and processing requirements increase
Solution Approach 1:
The patent creates a simplified copy of the compensation function by storing pre-computed correction values in a lookup table. Instead of implementing the full complex control algorithm in real-time, the system uses a simplified version that retrieves pre-calculated data, maintaining compensation effectiveness while dramatically reducing computational complexity.
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
The solution provides rapid and precise throttle control by compensating for cogging torque, ensuring accurate air intake volume without significant computational overhead, suitable for machines like tractors, lawnmowers, and motorcycles.
Implementation Method 1
a DC electric motor that is able to command the opening or the closing of the throttle valve
Implementation Method 2
a position sensor able to measure the position of said throttle valve
Data Source
AI summary
A combustion engine throttle body includes an air circulation duct with a throttle valve rotationally mounted therein, a DC electric motor opening or closing of the throttle valve and includes a rotor having a cogging torque that oscillates with a predefined period. A position sensor measures the throttle valve position. An electronic control unit receives the position values of the throttle valve, calculates a throttle valve compensation angle value between zero and the value of the predefined period of the cogging torque from the measured opening angle of the throttle valve, from the predefined period value of the cogging torque, and from the predetermined angle correction value for the throttle valve, determines a command signal value for the electric motor from a predetermined correspondence table and from the calculated compensation angle value for the throttle valve, and commands the electric motor based on the determined command signal value.