# 4141 / Modeling and verification of a full-scale forestry vehicle real-time multi-physics digital tw Title: Modeling and verification of a full-scale forestry vehicle real-time multi-physics digital twin Authors: Mattias Lehto, Antti Tikanmäki, Torbjörn Lindbäck, Håkan Lideskog, and Magnus Karlberg Abstract: At Luleå University of Technology, an offroad vehicle capable of performing autonomous forwarding of full-scale logs, has been developed and built. This vehicle serves as a modular research platform, where different hardware, software, and algorithms can be exchanged, tested, and validated. To further facilitate this research, a real-time multi-physics digital twin of the vehicle has been developed. The digital twin can be executed either in fully virtual or in Hardware-in-the-Loop mode. Virtual and hybrid testing and development are expected to increase the efficiency, safety, and sustainability of these activities. Future envisioned use-cases also include machine learning and generation of auto-annotated detector training data. The digital twin features multibody simulation, hydraulics, contacts and collisions, flexible tires, emulated sensors, and co-simulation capabilities. The test environment is a physical environment that has been recreated digitally, using data from a UAV-mounted camera and lidar, as well as handheld RTK GPS measurements. Therefore, accurate GPS positions can be obtained from the digital environment. The digital twin is equipped with an emulated GPS sensor and can thus follow the same GPS tracks as the physical vehicle. This paper presents the development and verification of the digital twin model. Calibration and testing of the digital twin’s hydraulically actuated articulated joint is detailed, and the results are analyzed. The modeled hydraulics of the articulated joint show realistic dynamics. It is also shown that the level of detail of the wheel motors’ hydraulic circuits, affects the calibration of the hydraulics model of the articulated joint, as they affect the resistance during turning. Order the full paper: ISTVS members: receive three papers per year as part of your membership via the ISTVS Member Portal: --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://2023.istvs.org/submissions/papers/4141.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.