The tire five stiffness testing machine is mainly used for testing the mechanical properties of tires under static or quasi-static conditions. The online estimation of tire lateral stiffness requires a combination of dynamic data and real-time algorithms, which have significant differences in testing principles and application scenarios. The testing machine cannot be directly used for online estimation of lateral stiffness, but can provide basic data support for algorithms. The following is a specific analysis:
The Function and Limitations of Tire Five Stiffness Testing Machine
The tire five stiffness testing machine is a professional equipment used to test the mechanical properties of tires, which can complete various rigidity tests such as longitudinal, transverse, enveloping, twisting, and vertical. Its functional features include:
Multidimensional stiffness testing: synchronously measure longitudinal stiffness (tire rolling direction), lateral stiffness (lateral deformation), wrap stiffness (changes in tread curvature), torsional stiffness (circumferential shear), and vertical stiffness (support performance).
Composite testing capability: Can continuously complete auxiliary testing projects such as airtightness testing, resistance measurement, geometric dimension measurement, etc. under single clamping conditions.
Destructive testing: used for testing the longitudinal, transverse, wrapping, torsion, diagonal rigidity, vertical rigidity, and tire failure energy of tires to determine whether there are design or production defects.
However, the tire five stiffness testing machine is mainly used for testing the mechanical properties of tires under static or quasi-static conditions. Its testing speed is slow and cannot reflect the changes in tire lateral stiffness during dynamic driving in real time.
Online estimation method for tire lateral stiffness
Tire lateral stiffness is the ratio of tire lateral force to lateral deviation angle, which reflects the tire's ability to resist lateral deformation and has a significant impact on the handling stability of the vehicle. At present, the online estimation methods for tire lateral stiffness mainly include the following:
Direct method: Based on the linear two degree of freedom model of the car, the lateral stiffness of the tire is directly calculated by measuring parameters such as lateral velocity, yaw rate, and longitudinal velocity of the car, combined with mathematical methods such as least squares. This method has clear principles and efficient solutions, but it is only applicable within the linear range of tires.
GPS/INS integrated measurement method: Combining measurement data from Global Positioning System (GPS) and Inertial Navigation System (INS), and processing it through complex algorithms, online estimation of tire lateral stiffness is achieved. This method also has the characteristics of clear principle and efficient solution, but it is only applicable within the linear range of tires.
Acceleration change rate method: By measuring the acceleration change rate during the driving process of the car and combining it with the tire dynamics model, the lateral stiffness of the tire is estimated. This method has good adaptability and can reflect the lateral stiffness changes of tires in a nonlinear range, but it requires high-precision impulse sensors or high-performance signal filtering to reduce noise interference, so the cost is relatively high.
The combination of tire five stiffness testing machine and online estimation method
Although the tire five stiffness testing machine cannot be directly used for online estimation of tire lateral stiffness, it can provide important basic data support for online estimation methods. For example:
Provide static mechanical performance parameters of tires: The longitudinal, transverse, enveloping, torsional, vertical and other rigidity parameters of tires obtained through tire five stiffness testing machine can be used as input parameters or calibration basis for online estimation methods, improving the accuracy of estimation results.
Verify the accuracy of online estimation methods: Comparing and analyzing the tire lateral stiffness obtained by online estimation methods with the static lateral stiffness obtained by tire five stiffness testing machine can verify the accuracy and reliability of online estimation methods.