Wheel Slip Control Using Equivalent Inertia for Multi-Drive Vehicles
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Solution Overview
Problem
Existing vehicle control systems, such as TCS, face challenges in maintaining ideal wheel slip control due to control period delays and dependency on actual vehicle speed, leading to reduced stability and performance, especially in Four Wheel Drive vehicles, where effective frictional force management is crucial but difficult to achieve.
Innovation Solution
A method for controlling wheel slip in vehicles with multiple driving devices that calculates and adjusts driving or braking force commands based on real-time equivalent inertia information, allowing individual wheel control without relying on reference speeds or complex dynamics models, and adapts to different driving modes selected by the driver.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If reference speed is used to calculate wheel slip, then wheel slip control can be implemented, but control period delays and dependency on actual vehicle speed reduce stability and performance
Solution Approach 1:
The patent extracts the dependency on reference speed from the wheel slip control calculation. Instead of using reference speed (Vveh) to calculate slip ratio, the system directly uses wheel speed information from sensors to determine slip conditions and control driving/braking forces, eliminating the time delay associated with reference speed calculation and improving control responsiveness
Solution Approach 2:
The patent replaces the mechanical/dynamic model-based reference speed calculation with a direct sensor-based wheel speed measurement approach. By substituting the complex dynamics model with straightforward sensor data processing, the system achieves faster response time and improved stability without requiring actual vehicle speed calculations
2Measurement precision
If reference speed and complex dynamics models are used for wheel slip control, then control accuracy may be improved, but device complexity and calculation requirements increase
Solution Approach 1:
The patent extracts and removes the complex dynamics model and reference speed calculation components from the control system. By taking out these unnecessary elements, the system achieves wheel slip control using only essential wheel speed sensor data, reducing device complexity while maintaining sufficient measurement precision for effective control
Solution Approach 2:
Instead of calculating wheel slip by deriving it from reference speed and wheel speed through complex dynamics models, the patent inverts the approach by directly using wheel speed information to determine slip conditions and control forces, simplifying the measurement and control process
3Adaptability or versatility
If individual wheel control is implemented in Four Wheel Drive vehicles, then frictional force management improves, but control system complexity increases
Solution Approach 1:
The patent applies segmentation by independently controlling each wheel's driving or braking force based on individual wheel speed sensor data. The controller processes wheel speed information for each wheel separately and applies appropriate control forces to each drive wheel, enabling precise frictional force management without requiring a complex centralized control model
Solution Approach 2:
Each wheel effectively serves itself by using its own wheel speed sensor data to determine its slip condition and required control force. The system allows each drive wheel to be controlled independently based on its own measurements, reducing the need for complex inter-wheel coordination algorithms while improving adaptability to varying road conditions
Data Source
AI summary
A method for controlling wheel slip of a vehicle, which comprises a plurality of driving devices for generating driving force for driving the vehicle, includes: obtaining, by a controller, equivalent inertia information for each driving device based on operation information of each driving system during traveling of the vehicle; calculating, by the controller, a calibration amount for calibrating a driving force command or a braking force command for each wheel in real time by using the equivalent inertia information obtained; calibrating, by the controller, the driving force command or the braking force command for each wheel by using the calculated calibration amount; and controlling, by the controller, the driving force according to the calibrated driving force command or the braking force according to the calibrated braking force command.