Development and Testing of Advanced Door Opening and Closing Function

Abstract

The increasing electrification and digitalization of heavy-duty vehicles have created new opportunities to improve both vehicle functionality and aerodynamic performance. Reducing aerodynamic drag is an important criterion identified for lowering energy consumption and increasing vehicle range, and the integration of flush exterior components, such as door handles, can contribute to reducing surface discontinuities. This thesis investigates the development of a power-operated side-door system for a heavy-duty truck, with a focus on integrating power release, soft-close functionality and a flush exterior handle interface while retaining the existing latch mechanism and mechanical release as a backup. A structured product development process was used to gauge the user needs and understand contemporary door entry systems to then develop and evaluate the prototype. The existing door system was integrated with an electric linear actuator in place of the door checker to enable a multi-functional solution. The actuator mounting geometry, required stroke, opening angle and operating forces were determined through kinematic and force calculations. Furthermore, a geared motor-driven mechanism was developed for power release and cinching. The multi-stage gear system was developed to provide the required output torque to the latch, and the drivetrain was verified using Romax. The housing, gears and opening interface were subsequently refined through several prototype iterations and functional testing. A preliminary communication and control system was also developed and tested using an Arduino-based setup to coordinate the different components and demonstrate the operating sequence. The final prototype combined the developed actuator, latch interface, cinching and powerrelease functions, exterior handle interface and supporting test fixture into a functional system. The iterative development and testing process identified several practical limitations related to packaging, structural strength, electrical interface and component integration, which were addressed through successive design modifications. The results demonstrate the feasibility of integrating an electrically operated door system around an existing heavy-duty vehicle door, while the developed prototype provides a technical foundation for further refinement and integration toward a production-ready power-operated door system for heavy-duty vehicles.