Volume 71, Issue 11 - Special Issue: Methods, approaches, and applications in mobile machines; Guest Editors: Birgit Vogel-Heuser, Johannes Fottner and Michael Weyrich

As long as all of the messages are supported, the OPC UA standard allows for connections over non-IP networks, and for the use of alternate encoding schemes. However, the vast majority of commercial OPC UA solutions are IP-based and UA Binary-based. In this article, the performance of an OPC UA client-server architecture is analysed by sending UA binary-encoded messages over an ISO 11783 (CAN 2.0B) network, without security. It is found that sending and receiving a given readRequest/readResponse pair took an average of 1.3 ms via a local Ethernet network and 49.2 ms via an ISO 11783 network. It is shown that much of the preamble of OPC UA messages is fixed when using the None security policy, and that this information can be omitted from the data transfer to reduce the amount of data transferred.

Teleoperation of mobile machines can have benefits on numerous aspects, including improved safety, enhanced efficiency, and reduced environmental impact. However, effects like increased latency, lack of machine feeling and limited field of view result in challenges for operators. The use of VR-systems with operator head motion tracking could improve its application. This paper presents the investigation of a tele-remote control system, using a VR-visual feedback system including a stereo camera that mimics the operator’s head motion. An operator study was conducted to evaluate the influence of the tele-remote control system. It is shown that the investigated system is able to increase the achieved immersion and thus improve the operability of teleoperated mobile machines.

This paper focuses on the alignment of Graphical-User-Interface (GUI) applications and embedded devices. The main contribution is a benchmark approach that enables measuring and comparing the GUI rendering capability of embedded devices and provides a performance-oriented GUI design recommendation for an embedded device. The benchmark is tailored to common GUI applications and resource-limited devices, which are usually mounted in mobile machines. GUI applications can only be rendered smoothly if these devices have sufficient performance. A general benchmark concept is described and modeled in Unified Modeling Language (UML) at first, followed by a prototypical implementation and evaluation. It is demonstrated that the benchmark approach is applicable to GUI applications with different levels of complexity as well as embedded devices of different performance classes.

The development and testing of autonomous systems require sufficient meaningful data. However, generating suitable scenario data is a challenging task. In particular, it raises the question of how to narrow down what kind of data should be considered meaningful. Autonomous systems are characterized by their ability to cope with uncertain situations, i.e. complex and unknown environmental conditions. Due to this openness, the definition of training and test scenarios cannot be easily specified. Not all relevant influences can be sufficiently specified with requirements in advance, especially for unknown scenarios and corner cases, and therefore the “right” data, balancing quality and efficiency, is hard to generate. This article discusses the challenges of automated generation of 3D scenario data. We present a training and testing loop that provides a way to generate synthetic camera and Lidar data using 3D simulated environments. Those can be automatically varied and modified to support a closed-loop system for deriving and generating datasets that can be used for continuous development and testing of autonomous systems.

Facilitating communication via standardized interfaces is key to increase construction site collaboration and productivity. This paper firstly outlines different Machine-to-Machine (M2M) messaging protocols and their suitability for communication on construction sites. Secondly, a unified construction site communication and interface solution that allows for the seamless transfer of data in M2M, Machine-to-Server (M2S), and Server-to-Server (S2S) scenarios, encompassing all layers of an Internet-of-Things (IoT) infrastructure, is proposed. The findings show that predominantly Message Queue Telemetry Transport (MQTT) is suited for M2M communication at construction sites. Underscoring the value of frequent communication and collaboration at construction sites, different exemplary use cases are presented. Additionally, interoperability at all levels of exchange as well as a unified user frontend are emphasized as key requirements to increase application rates of automated communication and collaboration within the construction industry.

Automation in agricultural machinery is a crucial driver of productivity and sustainability. Some automation features like automated steering and real-time data analytics are already state-of-the-art. On the other hand, a human driver performs the optimization of the working speed manually, and the automation of this is an ongoing challenge. Process quality and process efficiency are the two main targets in this optimization. Agricultural soil tillage requires achieving both. Therefore, the correlation between process quality optimization and process efficiency is fundamental, and vice versa. The approach presented in this paper shows how the two optimization targets of efficiency and process quality can be optimized and aligned together. Optical sensors determine various parameters to describe and model the process quality. The measured machine state determines the characteristics of the interaction forces between the machine and the environment. A machine learning algorithm describes the relationships in the drivetrain. The two process targets are each predicted for different working speeds and are combined in the form of a boundary target and an optimization target to identify one optimized target speed value.