Mechatronic Components Research Articles

Integration of Mechatronic Functions on Additively Manufactured Components via Laser‐Assisted Selective Metal Deposition

AbstractThe current industrial revolution derives much of its momentum from value creation based on interconnected products and related data based services. Such products must fulfill both mechanical and electrical requirements, making them mechatronic systems. The production of such systems via additive manufacturing (AM) processes offers advantages in achievable complexity, reduction of the amount of individual components, and cost‐effective as well as sustaina ble production of small quantities. In this work, a process chain is presented that allows for refining additively manufactured 3D structures made from industry‐standard materials into mechatronic components by creating electrically conductive structures directly on their surfaces. The process chain is based on masking the component's surface and selectively removing the masking according to the circuit geometry using laser radiation. In a wet–chemical bath process, the surface is then exposed to palladium nuclei, the masking is fully removed and metal layers (copper/nickel/gold) are deposited by electroless plating. The procedure is developed using stereolithography as a model process for AM and transferred to four additional AM methods. In all cases, despite markedly different surface properties, good selectivity of metal deposition is observed as well as adhesion strength and conductivity comparable to industrially common injection‐molded laser direct structured mechatronic interconnect devices.

SysML’ – incorporating component properties in early design phases of automated production systems

Abstract Properties and environmental dependencies of mechatronic components like gear-drives and motors impact the overall performance of automated Production Systems. These properties, often in the form of characteristic curves, are only accessible from suppliers’ documents, like operating instructions or online catalogs. The proposed SysML’ profile integrates artifacts from SysML and UML into disciplinary views. It includes a reference mechanism to REXS (standard for gear properties) and ECLASS (standard for product data like UNSPSC) to overcome the semantic inconsistency of component properties and inclusion of curves. A metamodel is used for a more precise presentation of the proposed reference mechanism. Due to the static nature of a profile, a Business Process Modeling Notation is used to dynamically illustrate the benefits of SysML’ in the workflow.

Time delay in a mechatronic Power-HIL system: Analysis and model-based compensation

The Power-Hardware-in-the-Loop (PHIL) methodology enables testbed solutions that support the development of complex mechatronic components. In PHIL testing, a unit under test (UUT) is coupled with a virtual representation of its surroundings. As an example, a real railway pantograph current collector UUT can be tested in real-time interaction with a virtual overhead catenary. However, due to the closed-loop feedback interconnection and the exchange of power between real and virtual systems, such a PHIL control structure is highly sensitive to time delays in the signal paths which limits its performance, accuracy, and stability. In this work, methods to evaluate and compensate for the effect of time delays in a typical PHIL structure are proposed. A model-based PHIL control system is introduced to demonstrate the effect of time-delay compensation techniques, including utilising specific reduced-order models to achieve efficient time-delay compensation. The performance of the control system is demonstrated and validated via simulations and experiments on a scaled PHIL test setup, which is related to railway pantograph testing. In addition, criteria to analyse system stability are formulated and demonstrated with respect to uncompensated time delays and unknown UUT contact stiffness.

Organisms as sensors in biohybrid entities as a novel tool for in-field aquatic monitoring

Rapidly intensifying global warming and water pollution calls for more efficient and continuous environmental monitoring methods. Biohybrid systems connect mechatronic components to living organisms and this approach can be used to extract data from the organisms. Compared to conventional monitoring methods, they allow for a broader data collection over long periods, minimizing the need for sampling processes and human labour. We aim to develop a methodology for creating various bioinspired entities, here referred to as ‘biohybrids’, designed for long-term aquatic monitoring. Here, we test several aspects of the development of the biohybrid entity: autonomous power source, lifeform integration and partial biodegradability. An autonomous power source was supplied by microbial fuel cells which exploit electron flows from microbial metabolic processes in the sediments. Here, we show that by stacking multiple cells, sufficient power can be supplied. We integrated lifeforms into the developed bioinspired entity which includes organisms such as the zebra mussel Dreissena polymorpha and water flea Daphnia spp. The setups developed allowed for observing their stress behaviours. Through this, we can monitor changes in the environment in a continuous manner. The further development of this approach will allow for extensive, long-term aquatic data collection and create an early-warning monitoring system.

Load Cell Mechatronic Approach with Finite Element Analysis (FEA) in SolidWorks Design Development of a Small-Scale Egg Sorter

This research was about developing an automated small-scale egg sorting machine, equipped with mechatronic components, that can sort chicken eggs and place them in trays according to five (5) weight classifications: pewee, small, medium, large, and extra-large with the use of an Arduino load sensor. The machine was made up of a load cell sensor, an Arduino mega controller, a suction mechanism hanging from a rail system driven by a National Electrical Manufacturers Association (NEMA) stepper motor, and a set of five egg trays for the five (5) egg weight classifications. The Arduino Mega microcontroller was used to operate the machine's moving parts, pump, sensors, and LCD. The machine was equipped with an alarm system that produces a sound when the suction picks up the 13th egg of a full tray. The Finite Element Analysis (FEA) simulation was done using SolidWorks software to analyze the vacuum pump capacity and the effects of dynamic force on the eggs during the pick and place process. Testing results of the actual fabricated machine indicated that it was able to successfully weigh, pick through suction, sort, and place eggs into 2x6 trays according to weights. The accuracy was 92.55 percent.

Vibration resistance FBG temperature sensor fabrication and its application in the motor for hydraulic pump

This paper fabricated a fiber Bragg grating (FBG) temperature sensor with rapid response and excellent anti-vibration performance. The lightweight and miniaturization of the sensor provided favorable conditions for its application in mechatronic components. Specifically, the Invar capillary with an ultra-low thermal expansion coefficient was selected to package the FBG, which avoided the separation possibility between capillary and FBG under sharp temperature differences. It implied a wide temperature measurement range of the sensor. Nanometer copper suspension filled the tiny gap between capillary and FBG. Its good thermal conductivity brought a fast response speed close to the bare FBG. In addition, the jitter of FBG in the capillary was significantly reduced thanks to the nanometer copper suspension occupying its motion space. This sensor realized the reliability, rapidity and stability together. The FBG temperature sensor was applied to the temperature monitoring of small-size motor for hydraulic pump and achieved ideal results.

Development of an additive fabricated biped mechanical system

The use of mechatronic components and the incorporation of additive manufacturing into the process of product development have grown in popularity over the past several years. The goal of the research conducted in this paper is to develop a prototype of a monomobile biped mechanical system and to optimize the printing parameters for the additive manufacturing stage. This paper presents the modelling of the components of a biped mechanical system and the simulation of their operation. The modelling step is followed by setting the printing parameters in the dedicated Z-Suite software and creating the G-code for the Zortrax M300 Plus additive manufacturing equipment. Lastly, the paper presents the connection of the sensors to the Plusivo board, the mounting procedure to the 3D printed parts that make up the biped mechanical system as well as the operation methodology of the sensors. The resulting prototype is then used to monitor parameters specific to the sensors used.

Xamã : Optical character recognition for multi-domain model management

The development of systems following model-driven engineering can include models from different domains. For example, to develop a mechatronic component one might need to combine expertise about mechanics, electronics, and software. Although these models belong to different domains, the changes in one model can affect other models causing inconsistencies in the entire system. Only few tools, however, support management of models from different domains. Indeed, these models are created using different modeling notations and it is not plausible to use a multitude of parsers geared toward each and every modeling notation. Therefore, to ensure maintenance of multi-domain systems, we need a uniform approach that would be independent from the peculiarities of the notation. Notation independence implies that such a uniform approach can only be based on elements commonly present in models of different domains, i.e., text, boxes, and lines. In this study, we investigate the suitability of optical character recognition (OCR) as a basis for such a uniformed approach. We select graphical models from various domains that typically combine textual and graphical elements. We start by analyzing the performance of Google Cloud Vision and Microsoft Cognitive Services, two off-the-shelf OCR services. Google Cloud Vision performed better than Microsoft Cognitive Services being able to detect text of 70% of model elements. Errors made by Google Cloud Vision are due to absence of support for text common in engineering formulas, e.g., Greek letters, equations, and subscripts. We identified the multi-line text error as one of the main issues of using OCR to recognize textual elements in models from different domains. This error happens when OCR misinterprets one textual element as two separate elements. To address the multi-line text error, we build Xamã on top of Google Cloud Vision. Xamã includes two approaches to identify whether the elements are positioned on a single line or multiple lines, and merge those identified as positioned on multiples lines. With and without shape detection, Xamã correctly identified 956 and 905 elements, respectively, out of 1171. Additionally, we compared the accuracy of Xamã and state-of-the-art tool img2UML, and we observe that Xamã outperformed img2UML in both precision and recall, being able to recognize 433 out of 614 textual elements as opposed to 171 by img2UML.

A methodology for the detection of functional relations of mechatronic components and assemblies in brownfield systems

The huge potential of the Digital Twin and its benefits in use cases such as virtual commissioning or reconfiguration planning for production systems is often described and well known. One reason that the usage of Digital Twins is becoming increasingly important are current trends, such as individualized mass production, which lead to more frequent reconfigurations of production systems or require higher flexibility. At the same time, many production systems have been in productive use for some time, so-called brownfield systems. Most of them do not have a Digital Twin, but would benefit from one, if available. However, the creation of a Digital Twin is a significant additional effort, due to the creation of the underlying models and the relations between them. Some promising approaches for the creation of domain-specific models already exist, which can be used for the creation of the unconnected parts of a Digital Twin. However, there are still few results for the creation of inter-domain relations, which cause problems in the creation of Digital Twins. This paper therefore presents a methodology for the automated reconstruction of functional relations as well as the separation of functionally related component groups of the plant and its software. For this purpose, the methodology imports the native PLC code via XML, extracts the relevant information from the code and enriches the resulting information model with explicit information about implicit relations in the code. Based on this, various elements of the PLC code are analyzed and the relationship of individual mechatronic components, that are available as signals, are examined and quantified. Thus, a part of the required relations for a Digital Twin is recognized automatically. The methodology and its benefits for the Digital Twin creation is presented and explained using a modular production system with several manufacturing stations as a proof-of-concept.

Vehicle stability controller HiL validation on static simulator

In the automotive world, Hardware in the Loop (HiL) methodologies are used to speed up the design and calibration process of the various mechatronics components installed on the vehicle. Installing production parts on advanced driving simulator enables the performance assessment in realistic scenarios, including a test driver earlier in the design process. The scope of this work is to evaluate the effect of ABS and ESC system, replicating their influence on the steering wheel. A brake by wire production system has been installed on a static simulator, equipped with a EPSiL steering bench, capable of accurately replicate tie-rod forces on a production steering unit. Full brake, sine steer maneuvers have been carried out both on real vehicle and on virtual environment. The system showed its capabilities of replicating the same functionalities of the real vehicle, extending the static simulator potentialities to support the activities on calibration and test of vehicle systems.

Towards a formal framework for integrated design-optimization and control of mechatronicsystems.

This paper presents work towards a formal framework to support model-based integrated design and optimization of mechatronic products for early-phase conceptual design. This paper describes an integrated design framework through the introduction of its software implementation and a specific use case. The contribution is to introduce mathematical formalism to define the concepts, semantics, computation rules and system architectures of the formal framework. The advantage of the formal definitions is to clearly expose functionality and the limitations of the design framework and facilitate the software implementation. The modelling capability of the framework is enhanced to include non-linear mechatronic components, such as a two degrees-of-freedom arm. Further, an optimal proportional-integral-derivative control component is added to the software library supporting the framework.

Simulation of bypass electric water pump to reduce the engine warm-up time

There are several strategies have been developed in the automotive cooling system to improve engine thermal management. Basically, these designs use controllable actuators and mechatronic components such as electric water pump, controllable thermostat, and controllable electric fan to improve engine temperature control on most operating ranges. Most of the strategies are complicated and costly. This paper introduced a different approach to improve coolant temperature warm-up during cold start. The new strategy was by promoting a higher coolant flow rate inside the engine block by just installing an electric water pump in the bypass hose. The new approach’s cold start performance was studied using GT-SUITE on a transient model, complete with finite-element of engine block design, lubrication system, components friction model, engine with combustion model and vehicle system. The proposed strategy clearly showed faster coolant temperature increase (18 seconds faster compared to the conventional cooling system). The strategy not only increase the coolant temperature faster, but also increases the oil temperature faster, lower Friction Mean Effective Pressure (FMEP), and lower fuel consumption at certain condition during the warm-up period.

Mechatronic Design of a Robot for Upper Limb Rehabilitation at Home

This paper addresses the design of a novel bionic robotic device for upper limb rehabilitation tasks at home. The main goal of the design process has been to obtain a rehabilitation device, which can be easily portable and can be managed remotely by a professional therapist. This allows to treat people also in regions that are not easily reachable with a significant cost reduction. Other potential benefits can be envisaged, for instance, in the possibility to keep social distancing while allowing rehabilitation treatments even during a pandemic spread. Specific attention has been devoted to design the main mechatronic components by developing specific kinematics and dynamics models. The design process includes the implementation of a specific control hardware and software. Preliminary experimental tests are reported to show the effectiveness and feasibility of the proposed design solution.

Cognitive Mechatronic Devices for Reconfigurable Production of Complex Parts

This paper discusses a robotic cell that handles geometrically complex products, exploiting cognitive control and actuation systems for the manipulation, assembly and packaging. The individual mechatronic components, namely a 6-DoF gripper and a flexible assembly mechanism, have been designed via functional decomposition of the actual assembly and handling tasks. The flexibility of these mechanisms is exploited through control modules, performing different cognition functions at cell, resource and device level. The design approach can be generalized for tasks requiring dexterity and adaptation to products. A case study from the consumer goods sector, showcases the system’s reconfigurability and efficiency.

Acoustic Optimization of Mechatronic Direct Injection Systems and Analysis of the Effects on Robustness in System Operation

<div class="section abstract"><div class="htmlview paragraph">The tightening of the emission legislation and political and social demands for sustainable mobility are forcing the automotive industry to develop complex, high precision mechatronic drive systems. The increasing precision of mechatronic components generally leads to an increase in structural excitation and thus to a rise in noise. The so-called ticking of the fuel injection system has a rather low sound pressure level compared to the residual engine noise. Nevertheless, the impulsive and high frequency noise character leads to a decline concerning the perception of comfort and sound quality. In order to identify the sound quality of fuel injection systems as a frontloading measure, a system test bench has been developed which represents the structure-borne and airborne sound radiation of the stand-alone injection system in a close to series configuration. In this paper, measures for the acoustic optimization of injection systems and their effects on the robustness of the system are discussed. The focus is on engine idling, since at this operating point the ticking of the injectors and high-pressure pump can be perceived most clearly due to the low masking effects of other noise sources. For this purpose, the injection parameters were measured during full engine operation and transferred to the system test bench. By using a special development control unit, it was possible to modify the parameters, quantify their influence on the acoustic behavior and, based on this, define NVH optimized control strategies. For the robustness evaluation of the NVH optimized control strategies, key functions of the injection system were analyzed under varying boundary conditions in system operation on an injection rate test bench.</div></div>

Automated Fiber Embedding for Soft Mechatronic Components

Many recent advances in smart composites for soft robotics have resulted from integration of long fibers to precisely control structural and functional properties. Compared to the time-consuming, laborious and error-prone process of manual long fiber placement typically used, Automated Fiber Embedding (AFE) has an enormous potential in soft robotics due to its repeatability, precision, and ease of integration with commonly used elastomers. In this work, three different approaches for automated layering and embedding of fibers inside silicone elastomers are presented. These techniques enable fabrication of soft composites comprising linear and free-form long fiber patterns without user intervention or manual post processing. To demonstrate the versatility of the techniques, several soft robotic applications ranging from actuators to inductive charging coils are presented.

Slip Estimation and Compensation Control of Omnidirectional Wheeled Automated Guided Vehicle

To achieve Industry 4.0 solutions for the networking of mechatronic components in production plants, the use of Internet of Things (IoT) technology is the optimal way for goods transportation in the cyber-physical system (CPS). As a result, automated guided vehicles (AGVs) are networked to all other participants in the production system to accept and execute transport jobs. Accurately tracking the planned paths of AGVs is therefore essential. The omnidirectional mobile vehicle has shown its excellent characteristics in crowded environments and narrow aisle spaces. However, the slip problem of the omnidirectional mobile vehicle is more serious than that of the general wheeled mobile vehicle. This paper proposes a slip estimation and compensation control method for an omnidirectional Mecanum-wheeled automated guided vehicle (OMWAGV) and implements a control system. Based on the slip estimation and compensation control of the general wheeled mobile platform, a Microchip dsPIC30F6010A microcontroller-based system uses an MPU-9250 multi-axis accelerometer sensor to derive the longitudinal speed, transverse speed, and steering angle of the omnidirectional wheel platform. These data are then compared with those from the motor encoders. A linear regression with a recursive least squares (RLS) method is utilized to estimate real-time slip ratio variations of four driving wheels and conduct the corresponding compensation and control. As a result, the driving speeds of the four omnidirectional wheels are dynamically adjusted so that the OMWAGV can accurately follow the predetermined motion trajectory. The experimental results of diagonally moving and cross-walking motions without and with slip estimation and compensation control showed that, without calculating the errors occurred during travel, the distances between the original starting position to the stopping position are dramatically reduced from 1.52 m to 0.03 m and from 1.56 m to 0.03 m, respectively. The higher tracking accuracy of the proposed method verifies its effectiveness and validness.

A comparison of thermally conductive polyamide 6‐boron nitride composites produced via additive layer manufacturing and compression molding

AbstractThermally conductive but electrically insulating polymer matrix composites are of great interest in many engineering applications such as thermal management applications (i.e., heat sinks in microelectronic packaging, cooling of mechatronic components and mechanisms). Among possible functional fillers, hexagonal boron nitride seems to be one of the most promising choice due to its high thermal conductivity, and in this work, it was used as filler of polyamide 6 matrix. The resulting composites were first prepared in the form of pellets, extruded into filaments, and successively 3D printed, with the aim to study and compare the thermal performances of the 3D printed samples to the ones manufactured using traditional compression molding technique. The thermal conductivity of 25% wt and 45% wt loaded compression molded samples were 1 and 2.5 W/mK, respectively, while the neat polymer showed a thermal conductivity of 0.29 W/mK. 3D printed samples showed the same trend, namely increasing thermal conductivity with filler amount, despite a great influence of the 3D printing processing parameters (i.e., melt rheology and printing temperature), which lower the resulting thermal conductivity. 3D printed 25% and 45% by weight loaded samples showed a through plane thermal conductivity of 0.67 and 0.92 W/mK, respectively, and in‐plane thermal conductivity of 0.96 and 1.52 W/mK due to the presence of porosity and filler alignment along the printing direction.

Simulink Implementation of the Data Distribution Service for Vehicular Controllers on Top of GBE and AFDX

AbstractVehicular networks have seen major changes in the past few years in order to offer reliable and real-time capable high-speed data transmission between electrical and mechatronic components to map current and future innovative functions into distributed systems within automotive applications. In the same context, the real-time middleware data distribution service (DDS) is an appropriate alternative for the standard vehicular middleware considering that it handles quality of service (QoS) parameters including real-time ones. In this paper, we are proposing a new approach for DDS implementation and integration into the vehicular system by creating a model-based design blocks. To validate this implementation, we have used the case of the Society of Automotive Engineers (SAE) vehicle benchmark as a simulation and test model. Therefore, we designed a Simulink vehicle as specified by SAE benchmark. Then, we have introduced a new methodology to link each module to a Simulink DDS blockset. The goal of this approach is to facilitate the use of DDS with vehicular controllers and to reduce the deployment and configuration complexities associated with DDS. It will also enable distributed real-time embedded systems developers to concentrate more on the business logic of the application instead of the low-level implementation details. The final developed architecture has been tested using three different types of real-time networks: FlexRay, Gigabit Ethernet and AFDX, to demonstrate that real-time application’s QoS are always met using this model.

Data-driven linear parameter-varying modelling of the steering dynamics of an autonomous car

Developing automatic driving solutions and driver support systems requires accurate vehicle specific models to describe and predict the associated motion dynamics of the vehicle. Despite of the mature understanding of ideal vehicle dynamics, which are inherently nonlinear, modern cars are equipped with a wide array of digital and mechatronic components that are difficult to model. Furthermore, due to manufacturing, each car has its personal motion characteristics which change over time. Hence, it is important to develop data-driven modelling methods that are capable to capture from data all relevant aspects of vehicle dynamics in a model that is directly utilisable for control. In this paper, we show how Linear Parameter-Varying (LPV) modelling and system identification can be applied to reliably capture personalised model of the steering system of an autonomous car based on measured data. Compared to other nonlinear identification techniques, the obtained LPV model is directly utilisable for powerful controller synthesis methods of the LPV framework.