287 research outputs found

    Real-time kinematics for accurate geolocalization of images in telerobotic applications

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    The paper discusses a real-time kinematic system for accurate geolocalization of images, acquired though stereoscopic cameras mounted on a robot, particularly a teleoperated machinery. A teleoperated vehicle may be used to explore an unsafe environment and to acquire in real-time stereoscopic images through two cameras mounted on top of it. Each camera has a visible image sensor. For night operation, or in case temperature is an important parameter, each camera can be equipped with both visible and infrared image sensors. One of the main issues for telerobotic is the real-time and accurate geolocalization of the images, where an accuracy of few cm is required. Such value is much better than that that provided by GPS (Global Positioning System), which is in the order of few meters. To this aim, a real-time kinematic system is proposed which acquires the GPS signal of the vehicle, plus through an RF channel, the GPS signal of a reference base station, geolocalized with a cm-accuracy. To improve the robustness of the differential GPS system, also the data of an Inertial Measurement Unit are used. Another issue addressed in this paper is the real-time implementation of a stereoscopic image-processing algorithm to recover the 3D structure of the scene. The focus is on the 3D reconstruction of the scene to have the reference trajectory for the actuation done by a robotic arm with a proper end-effector

    Real-time multi-camera video acquisition and processing platform for ADAS

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    The paper presents the design of a real-time and low-cost embedded system for image acquisition and processing in Advanced Driver Assisted Systems (ADAS). The system adopts a multi-camera architecture to provide a panoramic view of the objects surrounding the vehicle. Fish-eye lenses are used to achieve a large Field of View (FOV). Since they introduce radial distortion of the images projected on the sensors, a real-time algorithm for their correction is also implemented in a pre-processor. An FPGA-based hardware implementation, re-using IP macrocells for several ADAS algorithms, allows for real-time processing of input streams from VGA automotive CMOS cameras

    Sensing and connection systems for assisted and autonomous driving and unmanned vehicles

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    The special issue, “Sensors, Wireless Connectivity and Systems for Autonomous Vehicles and Smart Mobility” on MDPI Sensors presents 12 accepted papers, with authors from North America, Asia, Europe and Australia, related to the emerging trends in sensing and navigation systems (i.e., sensors plus related signal processing and understanding techniques in multi-agent and cooperating scenarios) for autonomous vehicles, including also unmanned aerial and underwater ones

    System-Level Analysis for Integrated Power Amplifier Design in mmWave Consumer Wireless Communications

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    System-level specifications for the design of integrated power amplifiers in mmWave wireless communications are derived in the paper. To this aim emerging standards for consumer applications such as wireless ultra-high definition (UHD) multimedia streaming or Gbit wireless LAN are considered (WirelessHD, WiGig, ECMA387, IEEE.802.11.ad, IEEE802.15.3c and upcoming 5G). A power amplifier design in 65 nm CMOS Silicon on Insulator (SOI) technology, targeting a 9 GHz UWB window from 57 to 66 GHz, is also proposed. To increase the power delivered to the antenna up to 18 mW, being still in the limit of maximum 1 dB compression point, multiple PA cores have been combined through a Wilkinson power combiner, but other solutions can be also explored for a better power efficiency and linearity

    Homogeneous and heterogeneous MPSoC architectures with network-on-chip connectivity for low-power and real-time multimedia signal processing

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    Two multiprocessor system-on-chip (MPSoC) architectures are proposed and compared in the paper with reference to audio and video processing applications. One architecture exploits a homogeneous topology; it consists of 8 identical tiles, each made of a 32-bit RISC core enhanced by a 64-bit DSP coprocessor with local memory. The other MPSoC architecture exploits a heterogeneous-tile topology with on-chip distributed memory resources; the tiles act as application specific processors supporting a different class of algorithms. In both architectures, the multiple tiles are interconnected by a network-on-chip (NoC) infrastructure, through network interfaces and routers, which allows parallel operations of the multiple tiles. The functional performances and the implementation complexity of the NoC-based MPSoC architectures are assessed by synthesis results in submicron CMOS technology. Among the large set of supported algorithms, two case studies are considered: the real-time implementation of an H.264/MPEG AVC video codec and of a low-distortion digital audio amplifier. The heterogeneous architecture ensures a higher power efficiency and a smaller area occupation and is more suited for low-power multimedia processing, such as in mobile devices. The homogeneous scheme allows for a higher flexibility and easier system scalability and is more suited for general-purpose DSP tasks in power-supplied devices

    Mm-wave integrated wireless transceiver: enabling technology for high bandwidth short-range networking in cyber physical systems

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    Emerging application scenarios for Cyber Physical Systems often require the networking of sensing and actuation nodes at high data rate and through wireless links. Lot of surveillance and control systems adopt as input sensors distributed video cameras operating at different spectral ranges and covering different fields of view. Arrays of radio/light detection and ranging (Radar/Lidar) sensors are often used to detect the presence of targets, of their speeds, distance and direction. The relevant bandwidth requirement amounts to some Gbps. The wireless connection is essential for easy and flexible deployment of the sensing/actuation nodes. A key technology to keep low the size and weight of the nodes is the fully integration at mm-waves of wireless transceivers sustaining Gbps data rate. To this aim, this paper presents the design of 60 GHz transceiver key blocks (Low Noise Amplifier, Power Amplifier, Antenna) to ensure connection distances up to 10 m and data rate of several Gbps. Around 60 GHz there are freely-available (unlicensed) worldwide several GHz of bandwidth. By using a CMOS Silicon-on-Insulator technology RF, analog and digital baseband circuitry can be integrated single-chip minimizing noise coupling. At mm-wave the wavelength is few mm and hence even the antenna is integrated on chip reducing cost and size vs. off-chip antenna solutions. The proposed transceiver enables at physical layer the implementation in compact nodes of links with data rates of several Gbps and up to 10 m distance; this is suited for home/office scenarios, or on-board vehicles (cars, trains, ships, airplanes) or body area networks for healthcare and wellness

    Gbps wireless transceiver for high bandwidth interconnections in distributed cyber physical systems

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    In Cyber Physical Systems there is a growing use of high speed sensors like photo and video camera, radio and light detection and ranging (Radar/Lidar) sensors. Hence Cyber Physical Systems can benefit from the high communication data rate, several Gbps, that can be provided by mm-wave wireless transceivers. At such high frequency the wavelength is few mm and hence the whole transciever including the antenna can be integrated in a single chip. To this aim this paper presents the design of 60 GHz transciever architecture to ensure connection distances up to 10 m and data rate up to 4 Gbps. At 60 GHz there are more than 7 GHz of unlicensed bandwidth (available for free for development of new services). By using a CMOS SOI technology RF, analog and digital baseband circuitry can be integrated in the same chip minimizing noise coupling. Even the antenna is integrated on chip reducing cost and size vs. classic off-chip antenna solutions. Therefore the proposed transciever can enable at physical layer the implementation of low cost nodes for a Cyber Physical System with data rates of several Gbps and with a communication distance suitable for home/office scenarios, or on-board vehicles such as cars, trains, ships, airplanes

    Cogging torque reduction in brushless motors by a nonlinear control technique

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    This work addresses the problem of mitigating the effects of the cogging torque in permanent magnet synchronous motors, particularly brushless motors, which is a main issue in precision electric drive applications. In this work, a method for mitigating the effects of the cogging torque is proposed, based on the use of a nonlinear automatic control technique known as feedback linearization that is ideal for underactuated dynamic systems. The aim of this work is to present an alternative to classic solutions based on the physical modification of the electrical machine to try to suppress the natural interaction between the permanent magnets and the teeth of the stator slots. Such modifications of electric machines are often expensive because they require customized procedures, while the proposed method does not require any modification of the electric drive. With respect to other algorithmic-based solutions for cogging torque reduction, the proposed control technique is scalable to different motor parameters, deterministic, and robust, and hence easy to use and verify for safety-critical applications. As an application case example, the work reports the reduction of the oscillations for the angular position control of a permanent magnet synchronous motor vs. classic PI (proportional-integrative) cascaded control. Moreover, the proposed algorithm is suitable to be implemented in low-cost embedded control units

    Real-time FPGA-based Radar Imaging for Smart Mobility Systems

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    The paper presents an X-band FMCW (Frequency Modulated Continuous Wave) Radar Imaging system, called X-FRI, for surveillance in smart mobility applications. X-FRI allows for detecting the presence of targets (e.g. obstacles in a railway crossing or urban road crossing, or ships in a small harbor), as well as their speed and their position. With respect to alternative solutions based on LIDAR or camera systems, X-FRI operates in real-time also in bad lighting and weather conditions, night and day. The radio-frequency transceiver is realized through COTS (Commercial Off The Shelf) components on a single-board. An FPGA-based baseband platform allows for real-time Radar image processing

    Radio Link Design Framework for WSN Deployment and Performance Prediction

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    To address the needs of Cyber Physical System applications, and particularly for an easy implementation of wireless sensor and actuator networks (WSAN), semiconductor companies are offering single-chip solutions embedding in the same device a microcontroller core with a wireless transceiver. These internet-on-chip devices support different connections [1-4]: Bluetooth, ZigBee and Bluetooth Low Energy at 2.4 GHz, Wi-Fi at 5 GHz, sub-GHz ISM (Industrial, Scientific, Medical) at 868/915 MHz or 315/433 MHz. The used microcontroller cores range from 8-bit 8051 for low-power short-range solutions to 32-bit Cortex-M ARM ones. The max. sustained bit-rates are from 250 kb/s (sub-GHz links) to 4 Mb/s (Wi-Fi). For example, in case of TI cc254x and cc31xx devices, there are different trade-offs between receiver sensitivity (from -74 dBm to -100 dBm) and maximum transmitter power (from 0 dBm to 5 dBm). These performance parameters lead to different link distances, but also to different power consumption levels, from few mW to several hundreds of mW. A range extender device can be added [5] to improve RX noise figure (down to 4.7 dB) and TX power (up to 22 dBm), although for a power overhead of 480 mW
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