Model uses micromechanical sensors to measure accelerations and track vehicle behavior along railroads
Researchers at USP’s School of Engineering (Poli) have developed a low-cost sensor capable of accurately monitoring the safety of freight and passenger trains. The device, which measures accelerations and estimates forces involved in rail travel, can be installed directly on railcars and locomotives, offering an affordable alternative to traditional systems used in industry, which are generally expensive and difficult to operate.
The equipment is based on micromechanical sensors – the same ones used in cell phones and vehicles – to capture translational and angular accelerations. As explained by Roberto Spinola, professor at Poli and coordinator of the Laboratory of Vehicle Dynamics and Simulation (LDSV), this information contributes to the monitoring of vehicle behavior.
Movement
According to him, the data is processed by an inverse dynamics algorithm, which estimates the forces acting on the train from the recorded movements. The goal is to evaluate the safety of the railway operation through the so-called safety index, which compares the vertical and lateral loads on the wheels of the trains. Excessive side loading, for example, may cause derailment of the vehicle.
The proposal seeks to replace or complement the use of the instrumented wheel, a traditional system that installs strain gauges directly on the wheels of trains to accurately measure the contact forces with the rails. Although efficient, the wheel is extremely expensive and requires a complex operation, which restricts its use to very specific tests.
“Our system does not perform a direct measurement like the wheel, but produces estimates with good quality of representation and has the great advantage of being extremely cheap”, says Spinola. He explained tha the sensor can be installed in all cars and locomotives of a train and work autonomously, powered by batteries that guarantee several days of continuous monitoring.
Monitoring systems
The professor explains that modern trains already have several sensors and automated control systems, such as ABS (anti-lock braking system), which measures wheel rotation and prevents slippage. The Poli group’s proposal is not to replace these technologies, but to join them as another layer of security, with the advantage of being able to be implemented in vehicles that do not yet have on-board monitoring.
“It is a system that circulates recording the performance over many kilometers, allowing to evaluate not only the vehicle, but also the conditions of the road and the operation,” summarizes Spinola. With this, operators can predict failures, adjust the speed of circulation and even plan interventions in the railway network more effectively.
Tests
Spinola reports that the technology has already been tested in different contexts. The USP team carried out experiments on CPTM (Companhia Paulista de Trens Metropolitanos) and Vale trains, a company responsible for much of the rail freight transport in Brazil. In addition, there are ongoing negotiations with other railway operators interested in the application of the device.
The professor points out that the sensor is fully developed and has already been patented by USP. He adds that the model is ready for commercial-scale use in railway and subway systems – allowing freight, passenger, medium-distance, and even metro trains to benefit from the innovation.
In addition to the direct contribution to safety, the technology has the potential to reduce operational costs and increase the efficiency of railway fleets, especially in countries such as Brazil, where there is a large extension of railways and rail transport is essential for the flow of cargo. “Modern systems are already endowed with many measuring systems and sensors. So this is another one of them, it is unprecedented and effectively contributes to safety”, highlights the professor.
English version: Nexus Traduções, edited by Denis Pacheco
