Přípravek pro automatizaci testování chyb na komunikačních a napájecích vodičích

Abstract

This master’s thesis deals with the design, implementation, and debugging of a fixture for the automation of selected electrical fault tests on communication and power lines in the automotive field. The addressed tests include in particular the simulation of disconnection, short circuit, and load connection on power lines up to 50 V / 15 A and on communication lines of the CAN, LIN, analog, and PWM types. The aim of the thesis was to replace the current manual execution of these tests with an automated solution allowing the definition of time parameters for the test.

The thesis includes an analysis of the current method of performing these tests, based on which a fixture using a relay network controlled by an ESP32 microcontroller was designed. The solution also includes a PC application, which enables the configuration of test sequences, communication with the device, and their execution via a serial interface, as well as firmware for the ESP32 module, ensuring local execution of test sequences, control of relay outputs, and processing of commands received from the PC application. In addition, the electrical circuit of the fixture, the layout of a multilayer printed circuit board and the mechanical construction of the device were designed.

The functionality of the designed fixture was verified by both software and hardware testing. The correct operation of the communication between the PC application and the firmware, the timing behavior of the relays, the current-carrying capability of the power paths, and the behavior of the device under voltage loading were verified. The result of the thesis is a functional device intended for practical use in an EMC laboratory, contributing to the automation of tests that are currently performed manually and to the improvement of their repeatability.