Study of the software migration of a position sensor in the actuator of a gearbox

Abstract

This study is being conducted at Ficosa Automotive and builds upon the final year project of another trainee at the company, focused on adapting and validating a new sensor to detect the position of an actuator’s cam in a gearbox serving as a Park Lock Actuator (PLA). It starts with the PCB used in Ficosa's project, equipped with newly assembled sensors, which are a dual sensor and an individual sensor. The aim of this study is to enable the individual sensor to communicate with the PCB's ECU and accurately detect the actuator's position, while exploiting the existing software developed for the previous sensor to minimize unnecessary work. The study begins with an examination of both the previous and new sensors, reviewing their respective datasheets to understand their operations. Subsequently, the existing software is analysed to comprehend the operation flow of the previous sensor, which is designed using state flow charts, and C and C++ code. Following this, modifications are made to the software, starting with C programming of functions for the new sensor and adjusting state flow charts as required. Once the new software is completed, it is implemented on the PCB, which is then installed on an actuator. Finally, three different tests are conducted on the sensor readings and mechanical operation of the actuator using the new software to verify if the specified objectives have been achieved. In the end, the study results in a completely functional individual sensor that detects the position of the actuator as it should, and some next steps are defined in order to complete the software for the dual sensor.