IVT Speed Ratio Control With Time-Delay Feedback Stabilization
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Solution Overview
Problem
Existing infinitely variable transmissions (IVTs) face challenges in achieving continuous variable speed ratios without decreasing transmission efficiency and reliability, particularly at high frequencies and low speeds, and struggle with torque limitations and vibrations, while also requiring sophisticated electronic control systems to optimize power distribution.
Innovation Solution
The development of a control system for IVTs that includes a crank length controller and a forward speed controller, utilizing electronic components to determine desired output rotation speeds and modulated input speeds, and output torque, with a time-delay feedback control mechanism to stabilize speed ratios and reduce fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a control system is added to optimize power distribution in IVTs, then fuel efficiency and dynamic performance are improved, but device complexity increases
Solution Approach 1:
The patent implements a closed-loop control system that continuously monitors output speed and adjusts the crank mechanism accordingly. Speed sensors detect actual output speed, and this feedback is used by the controller to modify crank position in real-time, ensuring optimal performance while managing system complexity through intelligent control rather than mechanical complexity
Solution Approach 2:
The patent replaces complex mechanical control mechanisms with an electronic control system. Instead of using purely mechanical linkages and governors to control speed ratio, the invention uses electronic sensors, microcontrollers, and actuators to achieve the same control function, reducing mechanical complexity while improving precision and fuel efficiency
2Use of energy by moving object
If the speed ratio is increased to improve fuel efficiency, then the prime mover can operate in optimal speed region, but transmission efficiency and reliability decrease at high frequencies and low speeds
Solution Approach 1:
The patent employs a dynamically adjustable crank mechanism that can continuously change its effective length to adapt to varying operating conditions. The crank position is actively controlled based on real-time speed and load conditions, allowing the transmission to maintain optimal efficiency across different operating regimes while preserving reliability through adaptive rather than fixed mechanical design
Solution Approach 2:
The patent changes the effective crank length parameter dynamically to optimize performance. By adjusting the crank radius or position within acceptable ranges, the system can maintain favorable speed ratios for fuel efficiency while avoiding the extreme conditions that would compromise transmission reliability, thus resolving the contradiction through parameter optimization
3Ease of operation
If clutch-to-clutch shifts are used to adjust speed ratios, then automatic transmission functionality is achieved, but torque interruption occurs during shifts
Solution Approach 1:
The patent extracts the speed ratio adjustment function from the clutch mechanism. Instead of using clutch engagement and disengagement to change gears, the invention uses a continuously variable crank mechanism that adjusts speed ratio smoothly without clutch intervention. This removes the source of torque interruption while preserving automatic transmission functionality
Solution Approach 2:
The patent prepares the crank mechanism in advance to enable continuous speed ratio adjustment. The crank is positioned and maintained in optimal positions throughout operation, allowing seamless transitions without the need for clutch-based gear changes that would cause torque interruption. The system proactively manages speed ratio rather than reactively changing gears
Data Source
AI summary
A nonlinear closed-loop control combined with an integral time-delay feedback control is disclosed to adjust a speed ratio of an infinitely variable transmission (IVT) system. A speed ratio control for an IVT system involves a forward speed controller and a crank length controller for different speed ranges. The time-delay control is designed to reduce speed fluctuations of the output speed of an IVT with an accurate speed ratio. The speed ratio of an IVT with the disclosed control strategy can achieve an excellent tracking response for the desired constant output speed and reduce speed fluctuations of the output speed of an IVT by the time-delay feedback control.