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In order to further improve positioning accuracy, this paper proposes an indoor vision/INS integrated mobile robot navigation method using multimodel-based multifrequency Kalman filter. Firstly, to overcome the insufficient accuracy of visual data when a robot turns, a novel multimodel integrated scheme has been investigated for the mobile robots with Mecanum wheels which can make fixed point angled turns. Secondly, a multifrequency Kalman filter has been used to fuse the position information from both the inertial navigation system and the visual navigation system, which overcomes the problem that the filtering period of the integrated navigation system is too long. The proposed multimodel multifrequency Kalman filter gives the root mean square error (RMSE) of 0.0184 m in the direction of east and 0.0977 m in north, respectively. The RMSE of visual navigation system is 0.8925 m in the direction of east and 0.9539 m in north, respectively. Experimental results show that the proposed method is effective. © 2021 Yuan Xu et al. open access

There is a growing pressure on antenna designers to provide ever increasing operating bandwidth, efficiency, and flexibility. Emerging communications standards are requiring operation over wide frequency ranges, often with multiple, separated bands of operation. This communication proposes and demonstrates an optically tunable cavity backed slot antenna. Through the incorporation of four silicon bridging pieces and a fiber coupled laser, the operating frequency can be tuned between 4.2 and 6 GHz. Antenna efficiency has been measured and ranges between 36% and 62% depending upon the combination of frequency and tuning state, with the gain taking values between 4.3 and 6.9 dBi. An effective fabrication process for the incorporation of silicon into the antenna has been described, as well as methods for effectively simulating the optically generated conductivity. Simulations and measurements show good agreement, and several proposed improvements are proposed for this novel and flexible tuning technology.

We provide an approach to reformulate the problem of extracting the information on scatterers in inverse problems. The approach is based on the recently introduced concept of singular value optimization and exploits the single scattering hypothesis of the Born approximation. A two-dimensional geometry with multifrequency/single-view plane wave illumination and TM polarization with near-field acquisitions is considered. Numerical results show how it is possible to dramatically reduce the number of near-field samples against the canonical ${{\rm{\lambda }}_{{\rm{min}}}}{\rm{/2}}$ criterion.

The proper understanding of blazar variability at the various electromagnetic spectral bands is one goal of multifrequency astrophysics. In this frame a peculiar and controversial phenomenology is the periodicity, postulated for long-term radio or optical flux light curves of about a dozen of blazars. The well-known BL Lac object OJ 287 (PKS 0851+202, S3 0851+20, PG 0851+202, z = 0.306) is not only a high-variable, peculiar, extragalactic source with hints for approximatively cyclical optical outbursts, but it also represents a case of substantial intensive and extensive (long-term) multifrequency observations. This rich database allow us a deeper analysis based on a wide range of variability timescales with some recent results that are highlighted here. © Copyright owned by the author(s).

International audience; In a recent communication, we presented a compact multi-frequency meander antenna [1]. This structure has a potential to be reconfigurable by using varactor diode. We plan to present this study in a future conference. In this paper, we present a mechanically tunable meander antenna by adjusting a floating ground plane placed under the meander structure. the use of mechanical tunable technique is very interesting because it provides a very simple handling of the power, no risk of nonlinearity and a continuous tunable capability. We present in this paper two possibilities of tunable device, one with the displacement of the floating ground plane and the second with the use of moving copper wires. Simulated and measured results are presented and discussed. © 2016 European Association of Antennas and Propagation.

Part VI: Haptics Applications; International audience; This paper presents a real-time physically based platform for multi-sensory interactive simulation. It is centred on high quality dynamic requirements driven by the concept of instrumental interaction and is able to render a wide variety of physical phenomena : from very rigid interactions to large and complex phenomena such pastes or plastic soils. The platform consists in a precisely synchronized multiprocessor architecture extended with a DSP board used for the simulation of very reactive models. It aims for obtain simulation rate necessary for rigid object (1KHz and more) in the context of 6 Degree of Freedom.