Development and Application of Co-simulation and "Control- oriented" Modeling in the Improvement of Performance and Energy Saving of Mobile Machinery☆

Abstract Due to rising energy costs and tighter emissions restrictions from law regulations, mobile machinery and off-road vehicles manufacturers are forced to develop and exploit new techniques for the reduction of fuel consumption and pollutant emission. The main focus in this direction is the optimization of the matching between the fluid power circuit and the thermal engine to improve the efficiency of the hydraulic system and reducing the fuel consumption. A specific research activity has been started in this field by the authors to define methods and techniques for the mathematical simulation of off-road vehicles, where usually hydraulic systems are powered by internal combustion engines. The models proposed in the paper and the related results clearly show how these simulation tools can be used to improve the energy efficiency of the overall system, leading to an interesting reduction in fuel consumption by merely changing the engine rotational speed instead of adopting a constant-speed strategy

MOCA: A Low-Power, Low-Cost Motion Capture System Based on Integrated Accelerometers

Human-computer interaction (HCI) and virtual reality applications pose the challenge of enabling real-time interfaces for natural interaction. Gesture recognition based on body-mounted accelerometers has been proposed as a viable solution to translate patterns of movements that are associated with user commands, thus substituting point-and-click methods or other cumbersome input devices. On the other hand, cost and power constraints make the implementation of a natural and efficient interface suitable for consumer applications a critical task. Even though several gesture recognition solutions exist, their use in HCI context has been poorly characterized. For this reason, in this paper, we consider a low-cost/low-power wearable motion tracking system based on integrated accelerometers called motion capture with accelerometers (MOCA) that we evaluated for navigation in virtual spaces. Recognition is based on a geometric algorithm that enables efficient and robust detection of rotational movements. Our objective is to demonstrate that such a low-cost and a low-power implementation is suitable for HCI applications. To this purpose, we characterized the system from both a quantitative point of view and a qualitative point of view. First, we performed static and dynamic assessment of movement recognition accuracy. Second, we evaluated the effectiveness of user experience using a 3D game application as a test bed

Hydraulic Hybrid Excavator: Layout Definition, Experimental Activity, Mathematical Model Validation and Fuel Consumption Evaluation

Energy saving and fuel consumption reduction techniques are among the principal interests for both academic institutions and industries, in particular, system optimization and hybridization. This paper presents a new hydraulic hybrid system layout for mobile machinery implemented on a middle size excavator. The hybridization procedure took advantage of a dynamic programming (DP) algorithm, which was also utilized for the hybrid components dimensioning and control strategy definition. A dedicated experimental activity on test bench was performed on the main components of the energy recovery system (ERS). The JCMAS working cycle was considered as the reference test for a fuel consumption comparison between the standard and the hybrid excavator. A fuel saving up to 8% on the JCMAS cycle, and up to 11% during the digging cycle, has been allowed by the proposed hybrid system

Energy saving solutions for a hydraulic excavator

Abstract Nowadays the improvement of energy efficiency and the reduction of pollutant emissions are the major challenges that the mobile machinery manufacturers have to face with. With rising fuel prices and increasingly stringent regulations, the development of energy saving solutions and efficient hydraulic system have become a priority for researchers and OEM's. One of the most effective approach is the machine hybridization but other solutions can be adopted. This paper proposes with the aid of mathematical tools energy saving solutions for an excavator equipped with a load sensing hydraulic system. A comprehensive energy analysis was conducted through the excavator model to highlight the energy dissipations along the system. Different solutions to reduce losses and improve fuel saving including energy recovery from boom and arm and the introduction of a second pump in the flow generation unit were identified and investigated in detail. Finally, combining the proposed solutions, a new hydraulic hybrid excavator concept was obtained with a 15% of fuel saving

Management of PALB2-associated breast cancer: A literature review and case report

Key Clinical Message Germline pathogenic variants (PV) of the PALB2 tumor suppressor gene are associated with an increased risk of breast, pancreatic, and ovarian cancer. In previous research, PALB2-associated breast cancer showed aggressive clinicopathological phenotypes, particularly triple-negative subtype, and higher mortality regardless of tumor stage, type of chemotherapy nor hormone receptor status. The identification of this germline alteration may have an impact on clinical management of breast cancer (BC) from the surgical approach to the systemic treatment choice. We herein report the case of a patient with a germline PV of PALB2, diagnosed with locally advanced PD-L1 positive triple-negative BC, who progressed after an immune checkpoint inhibitor (ICI)-containing regimen and then experienced a pathologic complete response after platinum-based chemotherapy. This case report hints a major role of the germline PALB2 alteration compared to the PD-L1 expression as cancer driver and gives us the opportunity to extensively review and discuss the available literature on the optimal management of PALB2-associated BC. Overall, our case report and review of the literature provide additional evidence that the germline analysis of PALB2 gene should be included in routine genetic testing for predictive purposes and to refine treatment algorithms

Fluorescent nanoparticles for sensing

Nanoparticle-based fluorescent sensors have emerged as a competitive alternative to small molecule sensors, due to their excellent fluorescence-based sensing capabilities. The tailorability of design, architecture, and photophysical properties has attracted the attention of many research groups, resulting in numerous reports related to novel nanosensors applied in sensing a vast variety of biological analytes. Although semiconducting quantum dots have been the best-known representative of fluorescent nanoparticles for a long time, the increasing popularity of new classes of organic nanoparticle-based sensors, such as carbon dots and polymeric nanoparticles, is due to their biocompatibility, ease of synthesis, and biofunctionalization capabilities. For instance, fluorescent gold and silver nanoclusters have emerged as a less cytotoxic replacement for semiconducting quantum dot sensors. This chapter provides an overview of recent developments in nanoparticle-based sensors for chemical and biological sensing and includes a discussion on unique properties of nanoparticles of different composition, along with their basic mechanism of fluorescence, route of synthesis, and their advantages and limitations

Modeling simulation and experimental verification of an excavator hydraulic system - Load Sensing Flow Sharing Valve Model

This paper describes the results of a study focused on the mathematical modeling of an excavator hydraulic system. From the viewpoint of designing and tuning an efficient control system, the excavator is a very complex nonlinear plant. To design and tune such a complex control system an extremely good nonlinear model of the plant is necessary. The problem of modeling an excavator is considered in this paper; a nonlinear mathematical model of an excavator has been developed using the AMESim® modeling environment to replicate actual operating conditions. The excavator model is described by detailed models of the main pump, valve block and kinematic model. The objective of this research is to develop a complete simulation model of an excavator with the capability of reproducing the actual characteristics of the system. The model could then be used as a platform to facilitate the study of alternate control strategies towards energy efficient systems and new controller designs for HIL. The novelty in the modeling approach is that the detailed component models have been developed to replicate actual conditions while not being demanding on computational time. This has been achieved through a balance of semi-empirical models, while maintaining the flexibility of varying the gain characteristics of the components for enhancing system performance. The benefit of this model is it provides an advantage on computational time for complex system modeling while not compromising on the systems characteristics. Hence, this paper presents the developed model of a complete excavator system with detailed verification of individual components and preliminary results of a complete excavator system

Simulation of an excavator hydraulic system using nonlinear mathematical models

This paper describes a mathematical modelling methodology developed for the rapid simulation of an excavator hydraulic system. The modelling approach presented enables a reduction of the control system development time for a complete excavator, while providing accurate system dynamics. A tool for defining an appropriate control strategy is a key point for satisfying the need for systems with better energyefficiency. Moreover, the model will be a significant support in investigating energy recovery solutions and evaluating the suitability of hybrid solutions (mechanical/hydraulic/electric). The hydraulic model, composed of the pump’s grey box model and the valve block white box model, has been validated on the basis of a set of experimental data collected on a test bench. The results of this study are presented in this paper

Analisi numerica e sperimentale del circuito idraulico di un escavatore – Modello di valvola distributrice “Load sensing” e “flow sharing

Il presente lavoro descrive i risultati di un’attività di modellazione e sperimentazione effettuata sul circuito idraulico di una macchina escavatrice. La simulazione dell’intero sistema permette di far emergere comportamenti spesso non deducibili dall’analisi dei singoli componenti, questo è l’obbiettivo principale dell’attività di ricerca presentata nel lavoro. La simulazione del sistema escavatore, comprensivo dei modelli della pompa principale, della cinematica dell’attrezzo frontale, e in particolar modo della valvola distributrice ha l’obiettivo di analizzare le interazioni tra i suoi componenti per ottenere un miglioramento globale delle prestazioni in termini sia di miglior controllo dei movimenti sia di minor consumo energetico. Aspetto fondamentale del lavoro è stata una intensa attività sperimentale, finalizzata a validare i modelli, svolta presso il Dipartimento di Ingegneria Industriale dell’Università di Parma