Óscar R. Polo

A Monoball Robot Based on LEGO Mindstorms [Focus on Education]

The LEGO Mindstorms kit is widely used in many areas of education and research, covering a number of applications from benchtop demonstrations to postgraduate research, laboratories, and projects [1][3]. Although the kit was initially designed as a toy for children over 12 years of age, its use in university courses is increasing yearly. The kit has attracted the interest of people working in many areas, including artificial intelligence, embedded systems, control systems, robotics, and operating systems. The LEGO Mindstorms kit is inexpensive, easily reconfigurable, reprogrammable, versatile, and robust, which makes it well suited for use in teaching [4].

Schedulability analysis of on-board satellite software based on model-driven and compositionality techniques

This paper presents the application of a model-driven and compositionality techniques for the real-time requirements validation of the on-board software for the Instrument Control Unit (ICU) of the Energetic Particle Detector (EPD) suite, which will be launched as a payload of the Solar Orbiter mission of the European Space Agency (ESA) and NASA. The main purpose of this approach is to automate the schedulability analysis of the on-board software. The complete solution integrates a component-based and automatic code generation tool, called EDROOM; RapiTime RVS 3.0, a tool that provides support for on-target execution time measurement; and an analysis tool, called MAST, to perform schedulability analysis. A framework called MICOBS is used to apply model-driven and compositionality techniques for the integration of the aforementioned tools, facilitating the transformations between the different models and allowing the automated generation of schedulability analysis reports.

Runtime instrumentation of SystemC/TLM2 interfaces for fault tolerance requirements verification in software cosimulation

This paper presents the design of a SystemC transaction level modelling wrapping library that can be used for the assertion of system properties, protocol compliance, or fault injection. The library uses C++ virtual table hooks as a dynamic binary instrumentation technique to inline wrappers in the TLM2 transaction path. This technique can be applied after the elaboration phase and needs neither source code modifications nor recompilation of the top level SystemC modules. The proposed technique has been successfully applied to the robustness verification of the on-board boot software of the Instrument Control Unit of the Solar Orbiters Energetic Particle Detector.

Unveiling modal parameters with forced response using SVD and QR during flutter flight testing

This article presents an algorithm for the identification of modal parameters during flutter flight testing when forced excitation is employed and the aircraft possesses several sensors for structural response acquisition. The main novelty of the method, when compared with other classical modal analysis methods, is that the analysis is carried out in intervals of time instead of in the whole duration of the excitation. It means that, even when the response signal is only partially available, some modal parameters may be still identified. Application to analytic signals as well as structural response of modern fighter aircraft using frequency-swept excitation is provided in order to demonstrate the effectiveness, robustness and noise immunity of the proposed method.

Signal Conditioning for the Kalman Filter: Application to Satellite Attitude Estimation with Magnetometer and Sun Sensors

Most satellites use an on-board attitude estimation system, based on available sensors. In the case of low-cost satellites, which are of increasing interest, it is usual to use magnetometers and Sun sensors. A Kalman filter is commonly recommended for the estimation, to simultaneously exploit the information from sensors and from a mathematical model of the satellite motion. It would be also convenient to adhere to a quaternion representation. This article focuses on some problems linked to this context. The state of the system should be represented in observable form. Singularities due to alignment of measured vectors cause estimation problems. Accommodation of the Kalman filter originates convergence difficulties. The article includes a new proposal that solves these problems, not needing changes in the Kalman filter algorithm. In addition, the article includes assessment of different errors, initialization values for the Kalman filter; and considers the influence of the magnetic dipole moment perturbation, showing how to handle it as part of the Kalman filter framework.

Integration of a preemptive priority based scheduler in the Palladio Workbench

We present an extension of Palladio Component Model for embedded systems.A set of patterns has been defined to model real-time systems in Palladio.A set of validation tests is provided to prove the correctness of the solution.A complete use case based on a real system is provided. This paper presents an extension to the Palladio Component Model (PCM), together with a new performance analysis infrastructure that supports the fixed-priority preemptive scheduling policy. The proposed solution allows modelling and analysing component-based embedded software applications that are defined using a specific pattern in which each component is executed by a task with a specific priority. The infrastructure is also capable of analysing the system performance when the tasks access shared resources, using either immediate priority ceiling, or priority inheritance protocols, in order to avoid the priority inversion problem. The paper shows the set of rules that enable the transformation between an application, compliant with the proposed design pattern, and its corresponding PCM. Finally, a use case example based on a real system, and a set of tests that validates the analysis infrastructure, are provided. This system is the on-board software of a satellite payload that is currently being developed by the Space Research Group of the University of Alcala. This software is in charge of managing the Instrument Control Unit of the Energetic Particle Detector, which will be launched as part of the Solar Orbiter mission of the European Space Agency and United States National Aeronautics and Space Administration (NASA).

Preliminary feasibility analysis of component based modelling and automatic Java code generation for nanosatellite on-board software: short paper

Nanosatellite on-board software is a real-time system that schedules and executes control actions over the platform and the payload subsystems during the mission stages. Its development is a complex task that can be better approached using advanced software engineering techniques as graphical component based modelling and automatic code generation. Nanosat1B is a scientific nanosatellite developed by the Spanish National Institute of Aerospace Technology (INTA) that was launched on July 09. This paper introduces the component base modelling and automatic code generation of Nanosat1B on-board software using a CASE tool named EDROOM. It shows the UML2 diagrams used for specifying the system components, their interfaces and behaviour, emphasizing on their reuse possibilities on the same domain. The paper describes also the main characteristics of the EDROOM tool and analyses the feasibility of its adaptation for automatic Java code generation. The benefits of using the EDROOM automatic Java code generation for nanosatellites on-board software development are also enumerated.