| 1. |
- Chen, Daru, et al.
(författare)
-
Some switchable dual-wavelength fibre lasers based on fibre Bragg grating feedback
- 2006
-
Ingår i: Proceedings of SPIE, the International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 6351, s. U864-U872
-
Tidskriftsartikel (refereegranskat)abstract
- Two methods to achieve dual-wavelength switching in a fibre laser are proposed and two corresponding switchable dual-wavelength fibre lasers based on fibre Bragg grating (FBG) feedback are demonstrated in this paper. In one proposed fibre laser, both Raman and Erbium-doped fibre (EDF) pumps are employed and the dual-wavelength switching is achieved by controlling the power of the Raman pump. In the other proposed fibre laser, an injection technique is used and the dual-wavelength switching is realized by controlling the power of the injection laser. The detailed behavior of the dual-wavelength switching in the two fibre lasers is experimentally studied and the principle is explained physically.
|
|
| 2. |
- Chen, Daru, et al.
(författare)
-
Switchable dual-wavelength Raman erbium-doped fibre laser
- 2006
-
Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 0013-5194 .- 1350-911X. ; 42:4, s. 202-204
-
Tidskriftsartikel (refereegranskat)abstract
- A fibre Bragg grating feedback fibre laser with both Raman and erbium-doped fibre pumps is proposed. Dual-wavelength switching is achieved by controlling the power of the Raman pump. The characteristics of the dual-wavelength switching are studied experimentally, and the mechanism is explained physically.
|
|
| 3. |
- Chen, Daru, et al.
(författare)
-
Tunable and injection-switchable erbium-doped fiber laser of line structure
- 2007
-
Ingår i: Microwave and optical technology letters (Print). - : Wiley. - 0895-2477 .- 1098-2760. ; 49:4, s. 765-768
-
Tidskriftsartikel (refereegranskat)abstract
- A tunable and injection-switchable erbium-doped fiber (EDF) laser is proposed based on a line structure formed by a fiber Sagnac loop reflector and an fiber Bragg grating (FBG). Wavelength switching is achieved by controlling the power of the tunable injection laser. The self-seeded wavelength corresponding to the Bragg wavelength of the FBG can be tuned by, for example, heating the FBG, and the injection wavelength can be tuned over a wide range of about 50 nm. The characteristics of the wavelength switching for different levels of the EDF pump power and different wavelengths of the injection laser are studied experimentally. The present fiber laser has the advantages of tunability, stability, low amplified spontaneous emission noise, and high injection efficiency when compared with a fiber ring laser. Rapid wavelength switching is expected and the transient switching response of the laser is also studied.
|
|
| 4. |
- Gbouna, Zakka Vincent, et al.
(författare)
-
User-Interactive Robot Skin With Large-Area Scalability for Safer and Natural Human-Robot Collaboration in Future Telehealthcare
- 2021
-
Ingår i: IEEE journal of biomedical and health informatics. - : Institute of Electrical and Electronics Engineers (IEEE). - 2168-2194 .- 2168-2208. ; 25:12, s. 4276-4288
-
Tidskriftsartikel (refereegranskat)abstract
- With the fourth revolution of healthcare, i.e., Healthcare 4.0, collaborative robotics is spilling out from traditional manufacturing and will blend into human living or working environments to deliver care services, especially telehealthcare. Because of the frequent and seamless interaction between robots and care recipients, it poses several challenges that require careful consideration: 1) the ability of the human to collaborate with the robots in a natural manner; and 2) the safety of the human collaborating with the robot. In this regard, we have proposed a proximity sensing solution based on the self-capacitive technology to provide an extended sense of touch for collaborative robots, allowing approach and contact measurement to enhance safe and natural human-robot collaboration. The modular design of our solution enables it to scale up to form a large-area sensing system. The sensing solution is proposed to work in two operation modes: the interaction mode and the safety mode. In the interaction mode, utilizing the ability of the sensor to localize the point of action, gesture command is used for robot manipulation. In the safety mode, the sensor enables the robot to actively avoid obstacles.
|
|
| 5. |
- Guo, Shaoyong, et al.
(författare)
-
Human Error Influence on the System Sensitivity of the Laser-assisted Navigation Calibration Instrument
- 2021
-
Ingår i: ICRSA 2021. - New York, NY, USA : Association for Computing Machinery (ACM). - 9781450384940 ; , s. 23-29
-
Konferensbidrag (refereegranskat)abstract
- *In the curved navigation of a wall-climbing robot, a laser navigation calibration instrument is designed to help the robot position on the wall. Human error can interfere with the input data in navigation, resulting in the decline of the output data's accuracy. In this paper, we analyze the sensitivity index of human errors in the process of navigation. There are several methods in the literature to determine the sensitivity indices of various human errors. Researchers have provided its validity. Compared with the Nonparametric Spearman rank-order correlation method, the simple analysis of variance technique, and the connection weight method, the Mean Impact Value (MIV) algorithm allows the effect of the output variables corresponding to each perturbation in the input variable to be recorded. As a machine learning method widely used in data analysis, BP neural network can significantly improve the experimental efficiency. The paper applied a technique to study the sensitivity index of human errors in navigation. This method integrates the Mean Impact Value (MIV) algorithm with BP neural network model by MATLAB. In the experiment, one thousand arrays of data are generated according to the paper of Design of a Laser-based Calibration instrument for Robot's Location Positioning on A Curved Surface. And these one thousand arrays of data are used to train a BP neural network model by MATLAB. The result of the BP neural network model is reliable, with the whole R is 0.99341. Due to the perturbations caused by each human error, five hundred arrays of data are generated in the input variable. This sensitivity analysis method could obtain an array of mean impact variables of human error by the MIV algorithm, which corresponds to each perturbation in the input variable. The results indicate that the perturbations caused by human error in the laser rotation angle a are greater than those in the laser-assisted navigation calibration instrument's original coordinate position. And the output variables increase linearly with the increase of the input error.
|
|
| 6. |
- Kabakova, Irina V., et al.
(författare)
-
Switching and dynamic wavelength conversion in a fiber grating cavity
- 2012
-
Ingår i: Journal of the Optical Society of America. B, Optical physics. - 0740-3224 .- 1520-8540. ; 29:1, s. 155-160
-
Tidskriftsartikel (refereegranskat)abstract
- Switching and dynamic wavelength conversion of light are demonstrated in a fiber grating cavity detuned by high-voltage electrical pulses. The cavity dynamics is studied using a heterodyne technique in which the frequency-shifted light, trapped by the cavity, mixes with the backreflected light at the incident frequency. We find that the frequency shift scales linearly with the energy of the electric driving pulses.
|
|
| 7. |
- Kong, Depeng, et al.
(författare)
-
Bioinspired Co-Design of Tactile Sensor and Deep Learning Algorithm for Human-Robot Interaction
- 2022
-
Ingår i: ADVANCED INTELLIGENT SYSTEMS. - : Wiley. - 2640-4567. ; 4:6
-
Tidskriftsartikel (refereegranskat)abstract
- Robots equipped with bionic skins for enhancing the robot perception capability are increasingly deployed in wide applications ranging from healthcare to industry. Artificial intelligence algorithms that can provide bionic skins with efficient signal processing functions further accelerate the development of this trend. Inspired by the somatosensory processing hierarchy of humans, the bioinspired co-design of a tactile sensor and a deep learning-based algorithm is proposed herein, simplifying the sensor structure while providing computation-enhanced tactile sensing performance. The soft piezoresistive sensor, based on the carbon black-coated polyurethane sponge, offers a continuous sensing area. By utilizing a customized deep neural network (DNN), it can detect external tactile stimulus spatially continuously. Besides, a novel data augmentation method is developed based on the sensor's hexagonal structure that has a sixfold rotation symmetry. It can significantly enhance the generalization ability of the DNN model by enriching the collected training data with generated pseudo-data. The functionality of the sensor and the robustness of the proposed data augmentation strategy are verified by precisely recognizing five touch modalities, illustrating a well-generalized performance, and providing a promising application prospect in human-robot interaction.
|
|
| 8. |
- Malmström, Mikael, et al.
(författare)
-
All-fiber cavity dumping
- 2009
-
Ingår i: Optics Express. - 1094-4087. ; 17:20, s. 17596-17602
-
Tidskriftsartikel (refereegranskat)abstract
- Cavity dumping of an all-fiber laser system is demonstrated. The active element is a pulse-picker with nanosecond rise time consisting of a microstructured fiber with electrically driven internal electrodes. The device is used for intracavity polarization rotation and dumping through a polarization splitter. The optical flux is removed from the cavity within one roundtrip and most of the amplified spontaneous emission, spiking and relaxation oscillation that follow during the gain recovery phase of the laser are blocked from the output signal.
|
|
| 9. |
|
|
| 10. |
|
|
