US-12623669-B2 - Tire analysis method and system for determining characteristic parameters of an agricultural tractor

US12623669B2US 12623669 B2US12623669 B2US 12623669B2US-12623669-B2

Abstract

A tire analysis method and system for determining characteristic parameters of an agricultural tractor provided with two front wheels supporting two front tires and with two rear wheels supporting two rear tires. A first rotation sensor is mounted on a first wheel, a second rotation sensor is mounted on a second wheel; the agricultural tractor is driven along a straight path; while driving the agricultural tractor along the straight path, the total number of revolutions made by the first wheel and by the second wheel are measured; and at least one characteristic parameter is determined using the total number of revolutions made by the first wheel and by the second wheel.

Inventors

Juan Carlos Fernandez
Antonio Fernandez
Maxim Gheorghe

Assignees

Bridgestone Europe NV/SA [BE/BE]

Dates

Publication Date: 20260512
Application Date: 20221125
Priority Date: 20211125

Claims (20)

1 . A tire analysis method for determining characteristic parameters of an agricultural tractor provided with two front wheels supporting two front tires and with two rear wheels supporting two rear tires, the method comprising: mounting a first rotation sensor on a first wheel, wherein the first rotation sensor is configured to measure a number of revolutions made by the first wheel and is separate and independent from the agricultural tractor; mounting a second rotation sensor on a second wheel, wherein the second rotation sensor is configured to measure a number of revolutions made by the second wheel and is separate and independent from the agricultural tractor; while driving the agricultural tractor along a straight path, measuring the total number of revolutions made by the first wheel and by the second wheel under actual operating conditions of the agricultural tractor; measuring, via a distance sensor, a distance traveled by the agricultural tractor while driving along the straight path, wherein the distance sensor comprises a receiver which is attached to a body of the agricultural tractor and a beacon placed in a fixed position on the ground nearby a travelling path of the agricultural tractor; dismounting the first and second rotation sensors from the respective wheels after the agricultural tractor has been driven along the straight path; determining at least one actual characteristic parameter for verifying tire setup for operation of the agricultural tractor, using the total number of revolutions made by the first wheel and by the second wheel while driving the agricultural tractor along the straight path, wherein at least a first characteristic parameter accounts for variations in actual operating conditions including at least one of: tire pressure, tire wear, and load per axle, and wherein at least a second characteristic parameter accounts for at least the measured distance traveled.
2 . The method of claim 1 , wherein each of the first and second rotation sensor is provided with a magnet configured to magnetically attach the respective rotation sensor to a rim of the respective wheel.
3 . The method of claim 1 , wherein: the first wheel and the second wheel belong to the same axle; and a first characteristic parameter is an axle balance calculated by dividing the total number of revolutions of the first wheel by the total number of revolutions of the second wheel.
4 . The method of claim 1 , wherein: the first wheel and the second wheel belong to a rear axle; during a first test the agricultural tractor is driven under operating conditions, on hard soil, and without load applied until the rear wheels turn a given number of times and a first running distance is measured at the end of the given number of revolutions; during a second test the agricultural tractor is driven under operating conditions, on a working field, and with load applied until the rear wheels turn the same given number of times of the first test and a second running distance is measured at the end of the given number of revolutions; and the at least second characteristic parameter comprises a real slip calculated by dividing the second running distance by the first running distance.
5 . The method of claim 1 , wherein: the first wheel and the second wheel belong to a rear axle; during a first test the agricultural tractor is driven under operating conditions, on hard soil, and without load applied until the rear wheels turn a first number of times and a first running distance is measured at the end of the first number of revolutions; during a second test the agricultural tractor is driven under operating conditions, on a working field, and with load applied until the rear wheels turn a second number of times and a second running distance is measured at the end of the second number of revolutions; and the at least second characteristic parameter comprises a real slip calculated by dividing the second running distance per rear tire revolution by the first running distance per rear tire revolution.
6 . The method of claim 5 , wherein the beacon is housed on a support laying on the ground.
7 . The method of claim 5 , wherein the receiver is attached to a rearmost part of the body of the agricultural tractor and the beacon is placed behind the agricultural tractor.
8 . The method of claim 5 , wherein the receiver of the distance sensor is provided with a magnet for magnetically attaching the receiver to the body of the agricultural tractor.
9 . The method of claim 1 , wherein: the first wheel and the second wheel belong to different axles; and the at least second characteristic parameter comprises a rolling circumference of each tire calculated by dividing the total running distance by the total number of revolutions.
10 . The method of claim 9 , wherein another characteristic parameter is an inter-axle ratio calculated as a measured number of revolutions for the front axle in a 4×4 On condition divided by a measured number of revolutions for the rear axle in the 4×4 On condition.
11 . The method of claim 9 , wherein another characteristic parameter is a lead ratio calculated as (([a measured number of revolutions for the front axle in a 4×4 On condition]/[a measured number of revolutions for the rear axle in the 4×4 On condition])/([a measured number of revolutions for the front axle in a 4×4 Off condition]/[a measured number of revolutions for the rear axle in a 4×4 Off condition]))−1.
12 . The method of claim 11 , wherein the beacon is housed on a support laying on the ground.
13 . The method of claim 11 , wherein the receiver is attached to a rearmost part of the body of the agricultural tractor and the beacon is placed behind the agricultural tractor.
14 . The method of claim 11 , wherein the distance sensor uses Ultra-Wideband Technology.
15 . The method of claim 11 , wherein the receiver of the distance sensor is provided with a magnet for magnetically attaching the receiver to the body of the agricultural tractor.
16 . A tire analysis system for determining characteristic parameters of an agricultural tractor provided with two front wheels supporting two front tires and with two rear wheels supporting two rear tires, wherein the tire analysis system comprises: a first rotation sensor configured, when detachably mounted on a first wheel and at least while driving the agricultural tractor along a straight path, to generate signals corresponding to a total number of revolutions made by the first wheel; a second rotation sensor configured, when detachably mounted on a second wheel, to generate signals corresponding to a total number of revolutions made by the second wheel; a distance sensor configured to measure a distance traveled by the agricultural tractor while driving along the straight path, wherein the distance sensor comprises a receiver which is attached to a body of the agricultural tractor and a beacon placed in a fixed position on the ground nearby a travelling path of the agricultural tractor; and a control unit configured to: while the agricultural tractor is driving along a straight path, receive the signals from the first rotation sensor and the second rotation sensor, respectively, and measure the total number of revolutions made by the first wheel and by the second wheel under actual operating conditions of the agricultural tractor; and determine at least one actual characteristic parameter for verifying tire setup for operation of the agricultural tractor, using the total number of revolutions made by the first wheel and by the second wheel, wherein at least a first characteristic parameter accounts for variations in actual operating conditions including at least one of: tire pressure, tire wear, and load per axle, and wherein at least a second characteristic parameter accounts for at least the measured distance traveled.
17 . The system of claim 16 , comprising a personal electronic device having a software application running thereon and which constitutes a Human-Machine Interface (HMI) for using the tire analysis system.
18 . The system of claim 17 , wherein the software application is configured to browse an Internet web site and exchange data therewith.
19 . The system of claim 16 , wherein the receiver is attached to a rearmost part of the body of the agricultural tractor and the beacon is placed behind the agricultural tractor.
20 . The system of claim 16 , wherein the receiver of the distance sensor is provided with a magnet for magnetically attaching the receiver to the body of the agricultural tractor.

Description

TECHNICAL SECTOR The present disclosure relates to a tire analysis method and a tire analysis system for determining characteristic parameters of an agricultural tractor. BACKGROUND In order to use four-wheel drive effectively, the running distance of front tires must be bigger than that of the rear tires—this is referred to as the lead ratio, and it is conditioned by the tires rolling circumferences and tractor's inter axle ratio. Tractor manufacturers normally recommend which tires can be mounted as standard, based on the rolling circumference data (at rated pressure and load, and full original tread depth) of new tires published by tire manufacturers. In many cases, several sizes are possible so long as they comply with the stipulated lead ratio. To use four-wheel drive effectively, the lead ratio should amount preferably to between +1% and +5% (the running distance of the front tires is longer than the running distance of the rear tires). The permitted lead ratio is normally accepted by the industry between 0% and +6%. A lead ratio less than 0% and greater than +6% can have a negative impact on the tractor's driving performance and steering behavior (particularly when less than 0%), and can cause excessive wear and tear in front and rear tires, as well as possible damages to the tractor's transmission. In four-wheel drive mechanisms, the relationship between the total number of revolutions of the front and rear axle is a constant factor (and is determined by the cogs in the gear box). This relationship is referred to as the inter axle ratio or transference ratio and, depending on the tractor brand and type, is normally between 1.20 and 1.50. Once you know the rolling circumference for front and rear tires, as well as the tractor's inter axle ratio, it is possible to calculate the lead ratio with the following formula: (rolling circumference front tire*inter axle ratio/rolling circumference rear tire)−1. But it is also necessary to consider that the standard calculations could be affected along the tractor's life, as many factors can affect to the rolling circumferences of the tires, for example the load per axle, the tire pressure applied by the customer, the wear rate, etc. or simply by replacing one axle worn out tires by new ones, and keeping in the other axle partially worn tires. All these situations will change the theoretical lead ratio and could therefore affect the proper performance of the tractor and/or tires. Nowadays, at least three people are necessary for determining characteristic parameters of an agricultural tractor: one person driving the agricultural tractor along a test straight path and two persons looking at the tires to visually measure the total number of revolutions of the tires. BRIEF SUMMARY The aim of the present invention is to provide a tire analysis method and a tire analysis system for determining characteristic parameters of an agricultural tractor that are easy, quick and precise to implement. In particular, the tire analysis method and a tire analysis system of the present invention will easily help to verify and choose the best combinations of tires and/or the best set up for optimal performance. According to the present invention, a tire analysis method and a tire analysis system for determining characteristic parameters of an agricultural tractor are provided, as set forth in the appended claims. The claims describe preferred embodiments of the present disclosure forming an integral part of the present description. BRIEF DESCRIPTION OF THE DRAWINGS The present disclosure is now described in reference to the attached drawings, which illustrate a non-limiting exemplary embodiment, wherein: FIG. 1 is a schematic view of an agricultural tractor implementing the method of the present invention; FIGS. 2 and 3 are two schematic and plan views of the agricultural tractor of FIG. 1 with different positioning of rotation sensors; FIG. 4 is a schematic view of a rotation sensor coupled to a wheel of the agricultural tractor of FIG. 1; FIG. 5 is a schematic view of a distance sensor coupled to a body of the agricultural tractor of FIG. 1; and FIG. 6 is a schematic and plan views of the agricultural tractor of FIG. 1 showing some rotation speeds of various components. DETAILED DESCRIPTION In FIG. 1 an agricultural tractor is indicated as a whole by the number 1. The agricultural tractor 1 comprises two front wheels 2 (only one is visible in FIG. 1) equipped with two front tires 3, two rear wheels 4 (only one is visible in FIG. 1) equipped with two rear tires 5 (bigger than the front tires 3), and a four-wheel drive powertrain 6 which is powered by an internal combustion engine 7 and transmits the motion to all the four wheels 2 and 4 in the case of Mechanical Front Wheel Drive (MFWD) or Four Wheel Drive tractors (4WD). The agricultural tractor 1 is provided by a tire analysis system 8 designed to determine some data connected to the wheels 2 and 4 and in particular to the tires