Search results for "Drive"
showing 10 items of 543 documents
The on-line coupled atmospheric chemistry model system MECO(n) – Part 5: Expanding the Multi-Model-Driver (MMD v2.0) for 2-way data exchange includin…
2018
Abstract. As part of the Modular Earth Submodel System (MESSy), the Multi-Model-Driver (MMD v1.0) was developed to couple online the regional Consortium for Small-scale Modeling (COSMO) model into a driving model, which can be either the regional COSMO model or the global European Centre Hamburg general circulation model (ECHAM) (see Part 2 of the model documentation). The coupled system is called MECO(n), i.e., MESSy-fied ECHAM and COSMO models nested n times. In this article, which is part of the model documentation of the MECO(n) system, the second generation of MMD is introduced. MMD comprises the message-passing infrastructure required for the parallel execution (multiple programme mul…
Latent force models for earth observation time series prediction
2016
We introduce latent force models for Earth observation time series analysis. The model uses Gaussian processes and differential equations to combine data driven modelling with a physical model of the system. The LFM presented here performs multi-output structured regression, adapts to the signal characteristics, it can cope with missing data in the time series, and provides explicit latent functions that allow system analysis and evaluation. We successfully illustrate the performance in challenging scenarios of crop monitoring from space, providing time-resolved time series predictions.
Motivations, adoption and impact of voluntary environmental certification in the Italian Forest based industry: The case of the FSC standard
2017
Abstract Over the past few years several private voluntary schemes have been developed worldwide to address the environmental issues in the forest based industry. Using survey data, this study analyse the main factors motivating companies operating in the Italian forest based industry to implement FSC (Forest Stewardship Council) standard, as a tool to promote responsible forest management and traceability of derived products, and the impact of this standard on the economic and organisational results. The findings provide evidences that signalling mechanisms drive the entrepreneurs towards the adoption of FSC certification, followed by moral and ethical reasons. In terms of impact, emerges …
Chapter 4: Direct and indirect drivers of change in biodiversity and nature’s contributions to people.
2018
The aim of this chapter is to assess evidence of the status and trends of the drivers that affect biodiversity and nature’s contributions to people. There are three wider categories of nature’s contributions to people: regulating, material and non-material contributions, that are similar to, but not identical to classifications of ecosystem services (see Chapter 1). Ecosystems are dynamic interacting networks of animals, plants, fungi, and microorganisms, above and below ground and water-surfaces. These biodiverse networks of interacting organisms respond to a set of environmental factors such as climate, soil, or water conditions. Social-ecological systems also include human activities (di…
Control and design for efficiency improvement of permanent-magnet synchronous motor drives in household appliances
2011
This paper deals with some aspects of efficiency improvement of PMSMD (Permanent Magnet Synchronous Motor Drives). Particularly two aspects are focused: the control algorithm for the PMSMD, which allows to reduce the power losses of the electric drive without penalty on its dynamic performances and the optimization of an IPMSM (Interior Permanent Magnet Synchronous Motor) rotor configuration capable to increase the performances in terms of shaft torque production, limiting at the same time the rotor leakage flux. The loss minimization algorithm is here briefly analyzed, a test bed for experimental validation is presented and the data are analyzed. Experimental tests have been performed aimi…
EKF-based estimation and control of electric drivetrain in offshore pipe racking machine
2016
A typical challenge for electric drivetrains is to reduce the number of sensors required for control action or system monitoring. This is particularly important for electric motors operating in offshore conditions, since they work in hostile environment which often damages data acquisition systems. Therefore, this paper deals with verification and validation of the extended Kalman filter (EKF) for sensorless indirect field-oriented control (IFOC) of an induction motor operating in offshore conditions. The EKF is employed to identify the speed of the induction motor based on the measured stator currents and voltages. The estimated speed is used in the motor speed control mode instead of a ph…
Integrated Design Optimization of a 5-DOF Assistive Light-weight Anthropomorphic Arm
2011
An integrated dimensional and drive train optimization method was developed for light-weight robotic arm design. The method deals with the determination of optimal link lengths and the optimal selection of motors and gearboxes from commercially available components. Constraints are formulated on the basis of kinematic performance and dynamic requirements, whereas the main objective is to minimize the weight. The design of a human-like arm, which is 10 kg in weight with a load capacity of 5 kg, is described. An integrated dimensional and drive train optimizationmethod was developed for light-weight robotic armdesign. The method deals with the determination of optimallink lengths and the opti…
Torque peak reduction and overload monitoring of induction motors in offshore drilling operations
2015
Current drivetrain design procedures for electric actuation systems operating in offshore conditions typically consider two major requirements: to provide sufficient steady-state and maximum motor torques. As a result of this, no information regarding the transient state (e.g. during motor acceleration) is utilized when selecting drivetrain components. This leads to potentially dangerous situations when motors undergo saturation in these regions due to too high dynamic loads. A common reason for this (apart from lack of information about transient state when designing a drivetrain) is applying trapezoidal reference motion profiles that cause discontinuities in system acceleration and infini…
Evaluation of performance and efficiency and type approval of an electrically assisted bicycle drive
2013
The diffusion of electrically assisted bicycles gives rise to the need of the evaluation of the performance and efficiency of the electric drive that supply it. In this paper, is presented a test bench for the estimation of the electric drive output torque under several speed and load conditions. Moreover, the test bench detects the electrical and mechanical parameters that allow to evaluate the electrical drive efficiencies. The test bench has been designed in agreement with the Directive 2002/24/EC of the European Parliament since it detects the maximum continuous rated power (that must be lower than 0.25 kW) and evaluates if the output is progressively reduced and finally cut off as the …
Dynamical Compensation of the Load Torque in a High-Performance Electrical Drive with an Induction Motor
2018
This paper describes a new method for dynamical estimation of load disturbance in induction motors by using Nonlinear Unknown Input Observers (NUIO). This estimation is then used to compensate dynamically the load torque in a Field Oriented Control (FOC) induction motor drive to increase its load-rejection capability. The method has been verified both in simulation and experimentally on a experimental rig.