Browse Topic: Tire pressure monitoring systems
Sumitomo Rubber Industries first announced its Sensing Core technology in 2017. But it wasn't until 2024 that the Japanese tire maker used its debut appearance at CES to promote the sensor-free signal analyzer. Sumitomo president and CEO Satoru Yamamoto said the company exhibited at CES, “to expand our partner companies and to get more drivers and companies to know about this sensing core technology.”
Several commercial truck OEMs revealed new medium-duty EVs at NTEA's 2023 Work Truck Week (WTW) in Indianapolis, Indiana. Interest in Class 5, 6 and 7 EVs has ramped up rapidly in recent years, and many OEMs are rolling out new models to meet the increased demand.
This SAE recommended practice defines the system and component functions, measurement metrics, testing methodologies for evaluating the functionality and performance of tire pressure systems, and recommended maintenance practices within the known operating environments. This document is applicable to all axle and all wheel combinations for single unit powered vehicles exceeding 7257 kg (16 000 US lb) gross vehicle weight rating (GVWR), and multi-unit vehicle combinations, up to three (3) towed units, which use an SAE J560 connector for power and/or communication, or equivalent successor connector technology, or which use a suitable capacity wireless solution. Examples of included single chassis vehicles would be – utility and delivery vans, tow trucks, rack trucks, buses, recreational vehicles, fuel trucks, trash trucks, dump trucks, cement trucks, and tractors. Examples of combination vehicles using an SAE J560 or successor connector would be – enclosed van trailers, liquid tanker, platform trailer, logger trailers, auto transit trailers, and their associated and compatible towing power units. For combination vehicles including two or more trailers, the dollies are also included. The included vehicles can be newly manufactured vehicles or existing vehicles. These systems are recommended to address all tires in service as originally installed on a vehicle by the OEM and/or specialty vehicle manufacturer, including the vehicle mounted spares, and, for the aftermarket (including replacement or spare parts) are recommended (but optional) to address all tire/rim combinations installed after initial vehicle sale or in-use dates. This document will focus on tire pressure systems of the monitoring type. NOTE: The following systems are not being addressed in this edition of the document. The management system types and more mature/complex versions of maintenance and management types, to include on-board reporting/storage/retrieval data capabilities for both, will be addressed separately by future changes/additions to this document series. 1] Tire Pressure Maintenance Systems – (typically known as ATIS – Automatic Tire Inflation Systems) systems which sense pressure directly or indirectly and maintain tire pressure above a minimum specified threshold, and inform the driver of the system’s activity. 2] Tire Pressure Management (adjustment) Systems (typically known as CTIS – Central Tire Inflation Systems) – systems which sense pressure, plus other pertinent parameters (i.e., vehicle load and speed, tire temperature, etc.) directly or indirectly, and adjust or sustain the pressure at a the level appropriate for the conditions, and inform the driver of the system’s activity.
This SAE Recommended Practice defines the system and component functions, measurement metrics, and testing methodologies for evaluating the functionality and performance of ground vehicle tire pressure maintenance (ATIS) systems (systems which automatically restore the inflation pressure to its specified level), and recommended maintenance practices for these systems within the known operating environments. These systems are recommended to address all serviceable tires as originally installed on a vehicle by the OEM and/or specialty vehicle manufacturer, and for the aftermarket (including replacement or spare parts) are recommended (but optional) to address all tire/rim combinations installed after initial vehicle sale or in-use dates. This document is applicable to all axle and all wheel combinations for the following vehicle types - single unit powered vehicles exceeding 7257 kg (16 000 lb) gross vehicle weight rating (GVWR), and multi-unit vehicle combinations, up to three towed units, which use an SAE J560 connector for power and/or communication, or equivalent successor connector technology. For combination vehicles including two or more trailers, the dolly axles are also included. The included vehicles can be newly manufactured vehicles or existing vehicles, fitted with air or hydraulic braking systems. SPECIAL NOTE: Equipment known as ‘dual tire equalizers’ are commonly used with this category of vehicles. When employing an ATIS system, dual tire equalizers systems are not recommended as they run counter to the purpose of the maintenance system. NOTE: The following systems are not being addressed in this edition of the subject document. 1 The management system types and more mature/complex versions of maintenance and management types, to include on-board reporting/storage/retrieval data/control capabilities, will be addressed separately by future changes/additions to this document series. 2 Tire pressure monitoring systems - These systems have been addressed under SAE J2848-1.
Tire inflation pressure has a significant impact over vehicle driving dynamics, fuel consumption as well as tire life. Therefore, continuous monitoring of tire pressure becomes imperative for ride comfort, safety and optimum vehicle handling performance. Two types of tire pressure monitoring systems (TPMS) used by vehicles are - direct and indirect TPMS. Direct systems deploy pressure sensors at each wheel and directly send pressure value to the vehicle Controller Area Network (CAN). Indirect sensors on the other hand use the information from already existing sensors and some physics-based equations to predict the value of tire pressure. Direct TPMS tend to be more accurate but have higher cost of installation while indirect TPMS comes with a minimum cost but compromised accuracy. A digital proof-of-concept study for indirect TPMS development of a non-ESP vehicle based on machine learning (ML) technique is elaborated in this paper. The study aims to propose a methodology for development of an indirect TPMS having an accuracy equivalent to that of a direct TPMS. A full vehicle model designed in Amesim software is used to extract data to train the machine-learning algorithm for different test cases. Simulation model is validated against the test data of vehicle dynamics parameters to ensure the accuracy of data extracted for ML model training. Multilayered feed forward, back-propagation artificial neural network is trained using three prediction algorithms and sensitivity of different algorithms, network parameters is analyzed against selected driving scenarios. Proof-of-concept study suggests that the proposed tire pressure prediction algorithm has a potential to predict tire pressure accurately at par with Direct TPMS. It lays a foundation for developing ML based indirect TPMS using physical testing data by providing assistance in test plan preparation, exploring data pre-processing techniques and algorithm selection. Furthermore, the generic methodology mentioned in this paper can be referred for initial development of any ML based project.
This SAE Recommended Practice defines the system and component functions, measurement metrics, and testing methodologies for evaluating the functionality and performance of ground vehicle central tire inflation systems (CTIS), also known as tire pressure management systems or tire pressure control systems (TPCS). Systems of this type allow the driver to select the operational tire pressure set point (TPSP) based on vehicle load and surface type (highway, off-highway, off-road, etc.) and maintain the inflation pressure to the vehicle specified level. These systems are recommended to address all serviceable tires as originally installed on a vehicle by the OEM and/or specialty vehicle manufacturer, and for the aftermarket (including replacement or spare parts) are recommended (but optional) to address all tire/rim combinations installed after initial vehicle sale or in-use dates. Systems for use by military and some other very rigorous off-road applications require such extreme performance requirements, particularly at very high and low temperature and other combat-based extremes that such applications may fall outside the recommended parameters of the subject document. In those cases, it is the responsibility of the procuring customer, vehicle OEM, and applicable component(s) OEM to determine what compromises might be required, and the suitability of design and performance solutions that may be outside of those recommended here. This document is applicable to all axle and all wheel combinations for the following vehicle types, but does not preclude its use on other vehicle types—single unit powered vehicles exceeding 7257 kg (16000 U.S. pounds) gross vehicle weight rating (GVWR) and multi-unit vehicle combinations, up to three towed units, which use an SAE J560 connector for power and/or communication, or equivalent successor connector technology. For combination vehicles including two or more trailers, the dolly axles are also included. The included vehicles can be newly manufactured vehicles or existing vehicles, fitted with air or hydraulic braking systems.
Tire pressure monitoring system (TPMS) is becoming ubiquitous in modern day vehicles with advanced safety and driver assist systems and plays a key role in predictive maintenance. One of the key challenges to realize an efficient TPMS system is to ensure good antenna coupling between the reader antenna in the cabin or on the roof of the vehicle and the antennas in the tires. Understanding the different external factors that affect the antenna coupling is vital to realize an efficient design. Computer aided simulations on antenna coupling is a cost-effective method to reduce the chances of failure before a TPMS is deployed in an actual vehicle. In this work, a computational approach is presented to optimize the antenna coupling and hence the link budget between the reader antennas and the TPMS antennas at 915 MHz. This is achieved by employing machine learning based optimization using commercially available tools, Altair’s HyperStudy and Altair’s Feko. A powerful combination of machine learning technique (regression-based mathematical modelling) to develop a surrogate mathematical model coupled with Global Response Search Method (GRSM) optimization is demonstrated for achieving the goals with very few design iterations A case study is presented that demonstrates the workflow process of optimizing the TPMS antenna coupling using body in white of an automobile. A comparison is also shown between traditional GRSM reader antenna position optimization and optimization coupled with machine learning showcasing significant reduction in computational time and memory.
Knowledge of the forces on the vehicle is necessary for designing most of the Baja vehicle subsystems, however little knowledge of the dynamic forces on small off-road vehicles is available. To measure the vertical and longitudinal forces on the tires of a Baja vehicle, a custom strain gauge system was designed and combined with Quarq tire pressure sensors while running in off-road conditions. The strain gauge system consisted of a half-bridge Wheatstone bridge of 350 Ohm resistors in bending, feeding the change in voltages into the 20-bit ADC of a Cypress Semiconductor PSoC 5LP microcontroller for data interpretation and then recorded onto an SD card for later analysis. Quarq Tyrewiz tire pressure sensors were placed on both the front and rear tires and the recorded pressures were converted to forces on the tire through calibration. Experimental data was found to agree with suspension models. Data from the strain gauges and tire pressure sensors are in agreement and when used to measure the forces on a 470 lbf Baja SAE vehicle with a driver inside, the dynamic bump forces were found to be as high as four to five times the static corner weight of the vehicle.
ERRATUM
This Recommended Practice provides common data output formats and definitions for a variety of data elements that may be useful for analyzing vehicle crash and crash-like events that meet specified trigger criteria. The document is intended to govern data element definitions, to provide a minimum data element set,and to specify EDR record format as applicable for light-duty motor vehicle Original Equipment applications.
Tire Pressure Monitoring System (TPMS) sensor measures air pressure and temperature in the tire and transmits tire information as wireless messages to TPMS central unit which consists of Radio Frequency (RF) receiver. TPMS central unit needs to determine the exact sensor locations (e.g. Front Left, Front Right, Rear Left or Rear Right) in order to correctly identify the location of the tire with pressure out of the desired range. The identified tire with abnormal pressure is highlighted on dash board in the car. Thus, determination of the location of a particular tire made automatically by the TPMS system itself or tire localization is required. TPMS tire localization is implemented currently in several methods. A new method is proposed in this paper. The proposed method uses at least two RF transceivers as repeaters. Each transceiver receives wireless messages (eg. Pressure, temperature, sensor ID) from the nearest TPMS sensor and re-transmits them with RF transceiver identity to TPMS central unit. RF transceiver is fixed near to each wheel in the car and its position is known to TPMS central unit. Based on its Received Signal Strength (RSSI), RF transceiver identifies sensor signal from the nearest TPMS sensor. To improve tire auto localization, an algorithm is developed by providing histogram distribution of wireless messages based on the signal strengths. The algorithm compares the histogram distribution to a predetermined histogram distribution to determine the position of the tire on the vehicle. The proposed method consumes less power and does not require additional wirings in the car as compared to using low frequency repeaters. Tire auto localization using hybrid method correlates sensor speed with wheel speed signal from anti braking system and so it involves access to other system. In practice, access to wheel speed signals is difficult.
This Recommended Practice provides common data output formats and definitions for a variety of data elements that may be useful for analyzing vehicle crash and crash-like events that meet specified trigger criteria. The document is intended to govern data element definitions, to provide a minimum data element set, and to specify EDR record format as applicable for light-duty motor vehicle Original Equipment applications.
Proper tire pressure is very important for multiple driving performance of a car, and it is necessary to monitor and warn the abnormal tire pressure online. Indirect Tire Pressure Monitoring System (TPMS) monitors the tire pressure based on the wheel speed signals of Anti-lock Braking System (ABS). In this paper, an indirect TPMS method is proposed to estimate the tire pressure according to its resonance frequency of circumferential vibration. Firstly, the errors of ABS wheel speed sensor system caused by the machining tolerance of the tooth ring are estimated based on the measured wheel speed using Recursive Least Squares (RLS) algorithm and the measuring errors are eliminated from the wheel speed signal. Then, the data segments with drive train torsional vibration are found out and eliminated by the methods of correlation analysis. Using the corrected and selected vibration noise, the resonance frequency of the tire vibration system is identified by Maximum Entropy Spectral Estimation (MESE) based on Auto-regressive (AR) model. Finally, the proposed algorithm is verified by test data, and the results show that the resonance frequency can be estimated and the changing of tire pressure can be indicated consequently.
This paper presents findings based on the examination of time-series tire pressure data. Tire pressure is important to vehicle safety due to its effects on vehicle handling and stability, as well as the impact that inappropriate tire pressure has on tire wear and tire failures. Previous research such as NHTSA’s 2001 Tire Pressure Special Study sampled vehicle populations and recorded tire pressures at a single point in time. Such studies yield important insights into tire pressures on individual vehicles and across the vehicle populations, but cannot provide insights into the behavior of tire pressures over time. The data presented in this paper was measured using the tire pressure monitoring system (TPMS) data from Tesla Model S vehicles. Using Tesla’s on-board diagnostic data logging and remote data retrieval capabilities, the time history of each vehicle’s tire pressures was recorded and fleet-wide data was analyzed. The resulting analysis provides insights into tire pressure changes caused by permeation and slow leaks as well as temperature fluctuations at both drive-cycle and seasonal time scales. The paper also includes examples of tire punctures with resulting pressure data.
Published information on studies of something so critical to safety as passenger vehicle tire pressures can be found [1, 2]; however, they only account for rolling tires. Studies related to spare tire pressures are lacking. This paper is the result of measurements on 150+ vehicles and the most surprising results are presented regarding the influence of Tire Pressure Monitoring Systems (TPMS) and the new spare tire locations and use. A statistical study was performed on the collected data to determine the correlation between tire pressures, vehicle age and TPMS. One particular topic of investigation was the relationship between various factors that influence spare tire pressure. Some newer models, particularly some mini-vans, have placed the spare tire in an unusual and inconvenient place for regular maintenance. Based on the data collected, TPMS has a positive influence on rolling tires but not on spare tires. The results support the need for TPMS to also monitor spare tire pressures.
Tire Pressure Monitoring System (TPMS) has become a popular system due to regulation in many countries. TPMS consists of sensors that measure air pressure and temperature in the tires. Each sensor transmits tire information to TPMS central unit for display purpose via RF. Commercial trailers having bodies longer than 7 m require RF repeaters to increase the data transmission range. Located near to rear wheels, RF repeater receives sensor signal in the rear wheels and transmits the signal to TPMS central unit. In this paper, we discuss RF repeater which transmits at multiple frequencies in order to increase signal reception. On TPMS central unit, RF receiver is able to tune to receive frequencies used in sensors and RF repeater. Other method for improving reception is to transmit same payload multiple times at same frequency as that of sensor. In the paper, other important specifications are discussed as RF repeater design is concerned. A user’s case of RF repeater is implemented. Time required for a complete transmission or reception is measured in the user’s case. As each TPMS sensor transmits periodically (e.g. 30 s) to the RF repeater, short time is required to change between receive and transmit modes for RF repeater. So the switching time between receive and transmit modes is measured in RF repeater. In the receive mode, RF repeater measures the Received Signal Strength Indication (RSSI). This RSSI can be used to indicate if location of RF repeater is optimum for receiving sensors in the rear wheels.
A tire is one of the most important performance and safety components in a two wheeler. An incorrect tire pressure not only impacts overall performance of a vehicle but also safety and overall fuel economy. The main purpose for appropriate tire pressure is to uniformly distribute vehicle load across the tire contact patch thereby providing an optimal contact between tire and road, effective handling, passenger comfort, maximum tire life and overall vehicle safety. A Tire Pressure Monitoring System (TPMS) measures a range of air pressure and alerts for proper tire pressure maintenance. Currently fully fledged tire pressure sensing systems are used in passenger cars and commercial vehicles. The use of such system in a two wheeler is yet to be recognized as precondition instead of an added attribute. This paper presents an objective methodology, based on analytical simulation and testing, developed in order to derive the optimal condition for front and rear tire pressures to achieve best performance in ride comfort, handling, braking and fuel economy. All findings justify the importance of TPMS, which ensures maintaining appropriate tire pressures for maximizing performance without substantial, high cost changes to the basic vehicle design.
Starting from the USA and followed by the European Union, legal requirements concerning “Tire Pressure Monitoring Systems” (TPMS) for passenger cars and light trucks will be introduced in China as well and therefore in the third of the three largest automobile markets worldwide. Changes of pressure dependent physical tire properties such as dynamic roll radius and a certain tire eigenfrequency, which are included in the ESC-wheel speed signals, indicates pressure loss in an indirect manner. Systems with corresponding working principles are called “indirect Tire Pressure Monitoring System” (iTPMS). Since the tire is a structural element with varying characteristics according to the design parameters, the roll radius and frequency behavior due to pressure loss is variable as well. As a consequence, tires have to be evaluated regarding there compatibility to iTPMS during the vehicle development process. In order to firstly reduce the testing effort on the complete vehicle and secondly to perform the evaluation at an earlier stage in the development process, tires shall be tested on external drum test rigs. This paper researches the systematic differences between the tire evaluation at whole vehicle driving tests on road and at tire test rigs. Based on testing results and simulation models the interaction of tire vibration behavior and suspension influences is analyzed as well as excitation characteristics of roads and cleat crossings.
Several wireless systems such as Dedicated Short Range Communication (DSRC), cellular, Wi-Fi, Bluetooth, and the Tire Pressure Monitoring System (TPMS) can be found on modern vehicles. In the future, Software Defined Radio (SDR) technology could be integrated into automobiles to increase the efficiency and adaptability of wireless communications systems. SDR is also a powerful tool for designing and testing new communications protocols. However there are also some security considerations associated with SDR. This paper will review some advantages of using SDR technology in the automotive domain as well as potential security issues. The authors are currently conducting research into the use of SDR technology to model wireless systems and investigate security threats in modern vehicular systems.
This Recommended Practice provides common data output formats and definitions for a variety of data elements that may be useful for analyzing vehicle crash and crash-like events that meet specified trigger criteria. The document is intended to govern data element definitions and EDR record format as applicable for light-duty motor vehicle Original Equipment applications.
This SAE recommended practice defines the system and component functions, measurement metrics, testing methodologies for evaluating the functionality and performance of ground vehicle CTIS. Systems of this type allow the driver to select the operational tire pressure set point (TPSP) based on off-highway conditions, and, upon returning to highway operations, maintain the inflation pressure to the vehicle specified level. These systems are recommended to address all serviceable tires as originally installed on a vehicle by the OEM and/or specialty vehicle manufacturer, and, for the aftermarket (including replacement or spare parts) are recommended (but optional) to address all tire/rim combinations installed after initial vehicle sale or in-use dates. Systems for use by military and some other very rigorous off-road applications require such extreme performance requirements, particularly at very high and low temperature and other combat-based extremes that such applications may fall outside the recommended parameters of the subject document. In those cases, it’s the responsibility of the procuring customer, vehicle OEM, and applicable component(s) OEM to determine what compromises might be required, and the suitability of design and performance solutions that may be outside of those recommended here. This document is applicable to all axle and all wheel combinations for the following vehicle types, but does not preclude it’s use on other vehicle types - single unit powered vehicles exceeding 7257 kg (16,000_US lbs) gross vehicle weight rating (GVWR), and multi-unit vehicle combinations, up to three (3) towed units, which use an SAE J560 connector for power and/or communication, or equivalent successor connector technology. For combination vehicles including two or more trailers, the dolly axles are also included. The included vehicles can be newly manufactured vehicles or existing vehicles, fitted with air or hydraulic braking systems. Special Note: Equipment known as ‘dual tire equalizers’ are commonly used with this category of vehicles. When installing a CTIS system, dual tire equalizers systems are not recommended as they run counter to the purpose of the management system. NOTE: The following systems are not being addressed in this edition of the subject document. 1 Tire Pressure Monitoring Systems - these systems have been addressed under SAE J2848-1. 2 Tire Pressure Maintenance Systems - these systems have been addressed under SAE J2848-2.
This SAE Recommended Practice defines the system and component functions, measurement metrics, and testing methodologies for evaluating the functionality and performance of ground vehicle tire pressure maintenance (ATIS) systems (systems which automatically restore the inflation pressure to its specified level), and recommended maintenance practices for these systems within the known operating environments. These systems are recommended to address all serviceable tires as originally installed on a vehicle by the OEM and/or specialty vehicle manufacturer, and for the aftermarket (including replacement or spare parts) are recommended (but optional) to address all tire/rim combinations installed after initial vehicle sale or in-use dates. This document is applicable to all axle and all wheel combinations for the following vehicle types - single unit powered vehicles exceeding 7257 kg (16 000 lb) gross vehicle weight rating (GVWR), and multi-unit vehicle combinations, up to three towed units, which use an SAE J560 connector for power and/or communication, or equivalent successor connector technology. For combination vehicles including two or more trailers, the dolly axles are also included. The included vehicles can be newly manufactured vehicles or existing vehicles, fitted with air or hydraulic braking systems. SPECIAL NOTE: Equipment known as ‘dual tire equalizers’ are commonly used with this category of vehicles. When employing an ATIS system, dual tire equalizers systems are not recommended as they run counter to the purpose of the maintenance system. NOTE: The following systems are not being addressed in this edition of the subject document. 1 The management system types and more mature/complex versions of maintenance and management types, to include on-board reporting/storage/retrieval data/control capabilities, will be addressed separately by future changes/additions to this document series. 2 Tire pressure monitoring systems - These systems have been addressed under SAE J2848-1.
Tires will be protagonists in the new European regulations for safety and fuel economy: in 2012 a tire pressure monitoring system will be mandatory for all new vehicles, enabling as natural consequence the development of the so called “intelligent tire”, able to capture all the relevant information of the contact between the road surface and the rubber, a starting point for new functions development to improve safety and reduce fuel consumption of all vehicles. A description of the methodologies that can be used to extract features from the tires, based on the experience of the development of Cyber Tyre, a high performance sensorized tire, is included in this work; comparison with the same information gained thorough ordinary sensors are provided too. The paper also presents some interesting examples of how data, coming from Cyber Tyres, can be exploited to improve the safety margins of a vehicle, preventing the critical operating condition represented by hydroplaning.
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