Author:
Ivan Zagan, Marketing Manager, Melexis
Date
07/21/2025
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Automotive trucks and heavy goods vehicles (HGVs) are key to nearly all critical markets and supply chains, facilitating the worldwide distribution of everything from food and medicine to fuels and electronic components. Given that 77% of inland freight in the European Union is transported by trucks, maximizing the efficiency, safety, and reliability of modern haulage vehicles is essential for automotive OEMs and fleet operators alike.
These three primary requirements, in conjunction with the global shift toward electric vehicles to mitigate emissions from transportation networks, have advanced the intelligence and capabilities of modern trucks. Functions ranging from advanced driver assistance systems (ADAS) to fully autonomous trucks are all designed to allow haulage networks to operate more efficiently and with fewer accidents.
To boost functionality and reliability, trucks are now incorporating more advanced digital and electric sensing systems that monitor various parameters, including lane position and proximity to other vehicles. Arguably, amongst the most important of such vehicle functions are tire monitoring systems, given the imperative importance of tire integrity. Tire pressure monitoring systems (TPMS) are crucial for accident prevention, better fuel economy, and lower maintenance expenses by constantly assessing tire health.
For the trucking industry, where margins are thin and operational reliability is vital, the importance of a tire monitoring sensor (TMS) cannot be overstated. Within this article, we will explore the evolution of large vehicle haulage networks, their effects on vehicle design, and how Melexis’ solution improves safety and efficiency for fleet operators.
TMS: A Key Enabler of Electric and Autonomous Trucks
Tires are a critical point of failure in heavy vehicles, particularly in long-haul operations. Sudden blowouts or uneven tire wear can lead to significant operational delays, increased costs, and, according to the Federal Motor Carrier Safety Administration (FMCSA), tire failures contribute to around 6% of US truck accidents, or about 8,000 crashes yearly. This underscore highlights the need for effective tire monitoring to mitigate risks and ensure operational reliability.
Compared to passenger EVs, the need for tire monitoring in heavy-duty vehicles is already greater due to higher axle counts, trailer integration, extended operational range, and the significantly higher gross vehicle weight. However, the industry-wide shift towards electric trucks to curb global emissions, as well as the emergence of autonomous trucks that could boost operational efficiency, exacerbate tire management challenges further.
For electric vehicles (EVs), the added weight of the batteries increases the load on the truck tires, thereby accelerating wear and increasing the risk of tire failure. For heavier trucks, TMSs play a crucial role in managing these stresses by ensuring optimal tire pressure, which not only enhances safety but also improves tire longevity and vehicle efficiency by reducing rolling resistance. This is particularly critical in EVs, where energy saved translates to more miles on the road.
Autonomous trucks introduce another layer of complexity. The absence of a human driver capable of detecting tire-related problems necessitates complete reliance on integrated electronic systems for monitoring and responding to vehicle and road conditions. In this scenario, a TMS becomes a vital indicator, providing essential data to the vehicle’s control systems to ensure safe operation. As an illustration, upon detection of a tire malfunction, a TMS can interface with the truck’s central control system, enabling actions such as rerouting or emergency braking as needed.
Conventional tire monitoring has been limited largely to air pressure measurement. Fully autonomous vehicles, however, will require more detailed data to ensure reliable operation over extended distances and unpredictable driving conditions. Through the integration of supplementary sensing mediums, such as an accelerometer, autonomous vehicles could intelligently detect road surface conditions as well as tire loading, assisting in identifying overloaded or unbalanced vehicles.
Innovating TMS Technology
The increasing demand for road freight is driving the evolution of smarter, more interconnected haulage networks, with more fleet operators using advanced telematics and IoT to optimize logistics. A smart TMS fits seamlessly into this landscape, providing critical tire data that can be integrated into vehicles and fleet management systems, enabling predictive maintenance, reducing downtime, and improving overall operational efficiency.
Furthermore, regulations around tire safety are tightening globally. From July 2024, all new trucks, trailers, buses, and coaches sold in Europe will require tire pressure monitoring systems (TPMS) from registration. Moving forward, governments will increasingly regulate heavy vehicles, particularly autonomous ones, to improve road safety and the environment. Consequently, automakers will seek smarter TMSs that surpass conventional TPMSs, but new technology must be easy to integrate and scale.
Melexis TMS Solutions
Melexis has a long history of innovation within the automotive industry, producing semiconductor solutions designed to meet the rigorous demands of vehicle deployment. Having identified the growing need for more advanced tire monitoring, it developed the MLX91805 – a smart tire sensor that combines multiple sensing capabilities within an incredibly compact 4 mm x 5 mm system-in-package (SIP) design.
A high-precision pressure sensing element is central to the device, facilitating highly accurate pressure measurement up to 1400 kPa and ensuring reliable truck tire pressure readings. However, unlike traditional TPMS sensors, Melexis’ smart devices incorporate a much broader range of functionality, including additional temperature and voltage sensors, as well as an 800g XZ-axis accelerometer that senses at up to 10,000 samples per second.
In operation, the inclusion of a high-precision accelerometer enables valuable tire deflection measurements. This data can be used to identify signs of uneven wear, determine when maintenance is needed, and estimate tire contact patch and vehicle load distribution. Such insights are particularly valuable for operators of heavy trucks, where uneven cargo weight can compromise both safety and efficiency. Moreover, in autonomous vehicles, the real-time multi-sensor data provided by the MLX91805 enables sophisticated control systems to detect tire condition, vehicle load, and road conditions, facilitating proactive tire health monitoring and autonomous operational adjustments.
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Figure 1: Tire deflection and alterations in the contact patch are detectable within the accelerometer’s frequency readings. (Source: Melexis)
Monitoring both pressure and temperature further helps to allow for early detection of potential problems, including underinflation, overheating, and mechanical issues such as slow wheel rotation, preventing premature tire wear. For heavy electric trucks, managing tire stress effectively, considering the gross vehicle weight, is crucial for maximizing tire life and operational efficiency.
The ultra-low-power sensor is controlled by an integrated 16-bit RISC MCU in a custom, pressure ported plastic DFN14 package. This enables efficient low-voltage operation from 3.6 V down to 1.8 V with a low 90 nA sleep current, helping to maximize battery life in operation. Ensuring consistent communication from inside a tire to external electronics is an embedded wireless 315/433 MHz RF transmitter and 125 kHz LF transceiver. Together with a few external components and a battery, the MLX91805 is designed to represent the optimal solution for truck smart tire sensor applications, providing high performance and quick time to market.
To help support engineers, Melexis also offers a comprehensive Reference Design Board (RDB) based on a qualified Bluetooth® Low Energy (LE) transceiver and a complete hardware and software design reference, from PCB to software, including LF/RF performance optimization.
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Figure 2: Melexis TMS solution located with a truck wheel (Source: Melexis)
This significantly speeds up development, enabling the creation of an ultra-low power TMS solution in the smallest possible footprint, enabling OEMs to meet the latest regulations for mandatory tire pressure monitoring in commercial heavy-duty vehicles, while supporting the future generation of smart tires.
Fleet Management: Elevated Insight for Increased Operational Efficiency
Beyond its role in enhancing safety and vehicle performance, the MLX91805 provides significant value to fleet operators. Access to real-time, detailed tire data allows operators to implement predictive maintenance strategies, reducing unexpected downtime and extending the lifespan of tires.
By identifying issues such as abnormal wear, underinflation, or overheating early, fleet managers can bring greater intelligence to scheduled maintenance, avoiding costly repairs and improving overall operational efficiency. This proactive approach not only reduces vehicle downtime but also helps lower the total cost of ownership (TCO) for fleets, a key consideration in highly competitive logistics markets.
The system’s ability to monitor tire deflection and load distribution also supports safer and more efficient haulage. Uneven load distribution, a common challenge in heavy haulage, can be identified and addressed before it leads to more severe issues. Furthermore, in the event of an autonomous truck emergency, for example, sudden tire pressure loss, the TMS can immediately notify fleet managers and initiate appropriate responses. This may include dispatching roadside assistance or redirecting the vehicle to the nearest service location, but in either case, disruptions are minimized, helping to keep the fleet on schedule.
Conclusion: The Future of TMS in Haulage
The integration of smart TMSs into haulage vehicles represents a nearly invisible but nevertheless important step in the evolution of the haulage industry. For electric and autonomous trucks, TMSs provide the critical data needed to ensure safety, efficiency, and reliability.
Melexis’ solution is already being adopted by leading automotive manufacturers in their autonomous vehicles, showcasing its effectiveness in supplying the detailed monitoring needed for contemporary transport vehicles. The MLX91805 and similar sensors from Melexis, such as the MLX91804, are designed to be exceptionally compact and efficient, making them ideal for integration into current and future vehicles without added complexity.
By delivering solutions that combine precision, efficiency, and scalability, Melexis is helping to support the industry’s shift toward safer and more efficient operations. As trucks continue to evolve, TMSs will remain essential in advancing safety, reliability, and operational excellence across the haulage sector.
