Arquitetura de retrofit eletrônico para telemetria, alertas e controle remoto: estudo de caso em pá-carregadeira Clark Michigan 55C

Abstract

Heavy machines built before the widespread adoption of embedded electronics remain in operation, but provide little digital information to operators and maintenance managers. In this context, this work developed and evaluated an electronic retrofit architecture for elemetry, fault alerts and remote control, using a 1990s Clark Michigan 55C wheel loader as a case study. The prototype was organized into four parts: embedded system, remote control, processing core and mobile application. On the machine, a Raspberry Pi 4 with a HAT and an ADS1115 converter read the pressure of the transmission governor pump through an analog transducer; the ESP8266-based remote control sent commands to pneumatic and electric actuators; the core, built with Apache Kafka and Apache Flink, normalized readings and issued alerts after temporal persistence; and the Flutter application displayed readings and alerts. The evaluation combined a single functional trial in a workshop, with the machine stationary, a bench check of the acquisition chain and synthetic resource-consumption tests. In the real trial, telemetry followed machine ignition and shutdown, and low-pressure alerts were received in the application. Boom, bucket-tilt and acceleration commands worked satisfactorily; however, the steering motor failed during the experiment and direction selection did not behave as expected, preventing any claim of complete teleoperation. The bench check indicated an approximately linear response of the 100 psi transducer, but it was not a metrological calibration, and the 500 psi transducer installed on the machine was not calibrated. In the simulated tests, with 1 vCPU, 1 GiB of memory and unitary parallelism, the core sustained about 200,000 samples/s before CPU saturation; at 1,000,000 samples/s, processed coverage fell to 17.9 – 18.7%. The 100% F1 score measures per-machine classification in the synthetic scenario, not the fraction of consumed messages. Thus, the contribution of this work lies in the integration and practical evaluation of the retrofit on the Michigan 55C, with explicit limitations regarding operational safety, link reliability, calibration and repetition of the real trials.