Tire Performance Simulations in Dynamic Conditions

Indoor tire testing device that can accurately simulate road conditions like rain, snow, and gravel for tire performance evaluation. The device allows testing on a rotating drum with simulated road surfaces, but it addresses the limitation of high-speed drum rotation by having a carriage that travels along the drum at a lower speed. This allows accurate testing of tire performance on specific road conditions by matching the carriage speed to the desired condition. The carriage and test wheel are both driven by a common power source, with a torque-applying device to isolate the wheel speed control from the power source. This allows the wheel to rotate at the carriage speed for accurate testing.

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Tire testing device that allows accurate evaluation of tire performance on simulated road surfaces, particularly for wet, snowy, or gravel conditions that are difficult to replicate in indoor testing. The device has a carriage that travels along a base with a test wheel mounted. The carriage and wheel are driven by a common power source, but the wheel speed is controlled separately using a torque applying device. This allows the wheel to spin freely at base speed when the torque device is inactive, then apply torque to match the wheel to the carriage speed. This maintains consistent wheel speed versus road speed, enabling accurate testing on simulated surfaces.

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Enclosed tire wear testing system that allows precise indoor wear testing of tires by controlling environmental conditions inside the test chamber. The system uses a rotatable drum with a tire mounted on a separate spindle connected by flexible bellows. The chamber has separate enclosures for the drum and tire. It has climate control to maintain temperature and humidity levels inside the chamber. Sensors measure temperature and humidity. Air is blown into the chamber if temperature exceeds a threshold and moisture added if humidity falls below a threshold to maintain desired conditions. This allows controlled indoor wear testing without external factors like temperature and humidity affecting the results.

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Indoor tire wear testing system that closely replicates outdoor conditions to more accurately predict real-world tire performance. The system uses an enclosed test chamber with a tire mounted on a spindle inside and the test drum outside, connected by flexible bellows. The chamber allows controlled temperature, humidity, and airflow to simulate various environments. Sensors monitor parameters like temperature and humidity inside the chamber. If they fall below thresholds, the system adds moisture or cools the chamber to match outdoor conditions. This allows testing in consistent, repeatable environments to better predict tire wear and performance in various conditions.

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Simulating the physical behavior of a tire in real time with accurate force computation in each time step even when the computation takes multiple iterations. The method involves updating the input variables periodically and then running an iterative algorithm to compute the estimated output variables. If convergence isn't reached in the current iteration, the algorithm continues in the next iteration and takes the previous iteration's result as the starting point. This allows the estimated variables to keep updating at a rate that meets real-time constraints while still ensuring accurate results.

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A device for evaluating tire rolling resistance that provides faster and more efficient measurement compared to traditional methods. The device uses smaller load rolls that simulate road surface contact instead of large drums. It moves the rolls back and forth under the tire while measuring load and position. By calculating phase difference between load variations and roll movement, it can evaluate rolling resistance without requiring large loads or motors. This reduces device size, power, and vibration compared to large drum systems.

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Method for generating tire load histories to simulate loads on a tire for indoor testing or computer simulation. The method involves identifying a vehicle test course, driving a vehicle on it, measuring accelerations and speed, generating a virtual test course from the measured data, collecting tire performance info, building a virtual tire, providing vehicle attributes, generating the tire load history by simulating the vehicle on the virtual course, and testing a physical tire against that history.

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Indoor tire testing device that allows realistic evaluation of tire performance on various road surfaces without actually driving on roads. The device has a carriage to hold the test wheel and a driving system. The driving system has separate power sources for speed and torque. The test wheel speed matches carriage speed, but torque is applied using a servo motor. This allows independent control of wheel speed and torque for simulation. The carriage travels on a road surface replica. A sensor array detects force distribution under the tire. Multiple profile images capture force distribution for 3 forces. This provides detailed load analysis beyond just average contact pressure. The device allows evaluating tire performance on a wide range of road conditions without actual driving.

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Device for quickly evaluating tire rolling resistance by using smaller, side-by-side load rolls that simulate road surfaces. The rolls alternate approaching and leaving the tire while sensors measure load and position. A calculation unit compares phase differences between load and roll position changes for the evaluation tire versus a reference tire. This allows faster rolling resistance measurement compared to traditional machines with large drums by reducing the required excitation force and avoiding vibration/fatigue issues.

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Method for generating tire load histories to simulate loads on a tire for indoor testing or computer simulation. The method involves collecting tire performance data, vehicle acceleration and speed data, and test course data. It uses this data to generate a virtual test course and simulate tire loading and wear on a computer. This allows testing tire wear without actually driving vehicles. The virtual tire and vehicle models are manipulated based on the simulated test course to match real-world loads and wear.

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Method of modeling tire performance for designing tires using a combination of physical testing and computer simulations. The method involves measuring forces and moments on a tire at various angles and loads during rotation, fitting curves to the data, and using the curves to evaluate and refine tire designs. It allows accurate modeling of tire behavior at low speeds and inclination angles that are difficult to measure physically. The method also involves creating reference curves for forces and moments, which can be adjusted and stored for future use in tire design iterations.

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A tire testing device that allows customization of testing conditions to match specific requirements. The device has a rotary drive unit, load drum, shape sensor, and control unit. It allows a user to input desired testing parameters like rotation speed, load, and sensor positions before the test. The control unit then uses these registered values during the test instead of preprogrammed defaults. This allows tailoring the testing conditions for each specific tire being tested, rather than using generic values.

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Accelerated wear testing of tires using a lab-scale setup to measure tire wear rates faster than normal driving. The method involves cutting a section from a tire and attaching it to one wheel. An abrasive substance is attached to another wheel. The two wheels are rotated at uneven speeds under a normal load for a short time. This causes slippage and wear in the tire section. The wear rate is measured based on changes in the section weight over time. The wear patterns of the section and whole tire are compared using periodic optical images. The rotation time is stopped when the section matches the whole tire pattern. This provides a faster, controlled way to measure tire wear compared to normal driving or indoor machines.

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Creating a scalable vehicle model (SVM) for tire testing that allows more accurate tire wear prediction across a range of vehicles without the need for testing on multiple specific vehicles. The SVM involves defining vehicle parameters like weight, center of gravity, suspension, etc. for an average vehicle segment. Regression functions relate these parameters to average values for the segment. By simulating forces and inclination angles on the SVM using vehicle dynamics, tire loads and wear can be predicted for any weight vehicle without testing on specific vehicles.

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A method for estimating the loaded radius of a tire that is more accurate and easier to implement compared to existing methods like the Pacejka "magic formula." The method involves using a formula to estimate the loaded radius based on tire forces like transverse thrust force. This allows predicting tire behavior in simulation tools by accurately capturing the radius changes during cornering and other maneuvers. The formula involves parameters like load, cornering, camber, speed, pressure, and temperatures.

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Testing drive trains without a differential gear by reproducing different road surfaces for both left and right tires in an I-shaped testing system where the test piece doesn't have a differential. The system uses a dynamometer, inverter, axial torque detector, speed sensors, and calculation units to simulate differential behavior. Tire speeds are calculated based on differential and vehicle driving torques. This allows reproducing different road conditions for both tires even without a physical differential.

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A method to improve accuracy of predicting tire performance on snowy roads and enable more efficient tire design cycles. The method involves using a snow model in tire performance simulations to better represent snow properties like compaction and shear. The snow model is created by stratifying snow alone at test conditions matching tire use speeds. This allows expressing snow density and shear as functions of pressure. By accurately modeling snow behavior, the tire performance prediction on snow becomes less dependent on snow properties and improves prediction precision.

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A system to test tire noise levels and identify defects using a load roller and sensors. The system applies a radial load to a tire on a roller and measures vibrations and acoustic signals as the tire rotates. A processor analyzes the signals to identify tire defects like flat spots, cupping, bubbles, foreign objects, and simulate tire noise at different speeds and surfaces. This provides a quantitative assessment of tire noise and defects for comparison between tires.

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Creating a scalable vehicle model (SVM) to accurately test tire wear and performance across a wide range of vehicles, without the need for testing on multiple actual vehicles. The SVM is defined based on vehicle segment characteristics like weight, wheelbase, suspension, etc. This allows predicting forces and angles exerted on a tire by an average vehicle in the segment, which can be used to simulate tire wear on an indoor tester instead of testing on specific vehicles. The SVM is generated through regression functions based on total weight and independent variables like jounce and steering angle.

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A system to evaluate tire noise, defects, and sources of distinct noises associated with a tire by applying a radial load to a wheel assembly and measuring mechanical vibrations using sensors during loaded rotational movement. The measurements are processed to identify tire defects like flat spots, cupping, bubbles, embedded objects, and simulate tire noise at different speeds and surfaces to provide a tire acoustics figure of merit.

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