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Precision physical quantity of sensing using ensembles of nitrogen vacancy (NV) centers in diamond has attracted wide interest in recent years. A widely studied prototype is a micron-sized diamond crystal mounted on a fiber tip which forms a scanning vectorial sensor for temperature, magnetic/electric field in the study of fundamental phenomena in condensed matter physics, bio-science and electromagnetics. A general issue in this application is the determination of the crystal orientation in the lab coordinate. In this work, we propose a practical method using an orthogonal 3-axis coil to determine the relative orientation of crystal in the coordinate of the coil (lab-frame coordinate). The transformational relation between the lab-frame coordinate and the NV body frame coordinate is established with the data of the optically detected magnetic resonance (ODMR) spectrum peak shifts and applied magnetic field vector. We demonstrate tunable RF field sensing using this micrometer sized probe, the proposed method is expected to find field imaging applications with frequency ranging from microwave to millimeter wave.

High-resolution field imaging with minimized invasiveness is of growing interest with the development of radio frequency (RF) integrated circuits and planar antenna characterization. In this paper, we propose an optical broadband sensor with static offset magnetic field using a diamond crystal that contains an ensemble of nitrogen-vacancy (NV) centers. The spatial resolution of micrometer scale is demonstrated by using a diamond crystal of this size. This technique is based on the modulation of fluorescence emitting by NV center under green laser excitation, by an off-axis magnetic field at radio frequencies. We demonstrate experimentally the detection of an RF magnetic field, with minimum measurable amplitude on the order of 0.1 Gauss, which is limited by the noise floor of the avalanche photodetector. The sensitivity can be further improved by noise suppression in optics. The bandwidth of the sensor is measured to be 15 MHz.

We present a microwave B-field scanning imaging technique using a diamond micro-crystal containing a nitrogen vacancy center that is attached to a fiber tip. We propose a pulsed modulation technique, enabling the implementation of a variety of pulsed quantum algorithms for state manipulation and fast readout of the spin state. A detailed mapping of the magnetic B-field distribution of a helical antenna with sub-100 μm resolution is presented and compared with numerical simulations. This fiber based microwave B-field probe has the advantages of minimized invasiveness and small overall size and will boost broad interest in a variety of applications where near field distribution is essential to device characterization, to name a few, antenna radiation profiling, monolithic microwave integrated circuit failure diagnosis, electromagnetic compatibility test of microwave integrated circuits, and microwave cavity field mode mapping.

The transmission gear is taken as the research object in this paper, the high damping alloy material is added to the gear to attenuate the vibration when the gears meshes. First, the gear transmission with damping alloy is compared with the traditional gear transmission through the rigid-flexible coupling model in ADAMS, and then the change of gear center acceleration during transmission is analyzed. The damping effect of the high-damping alloy material verifies that the increase of the gear damper can attenuate the vibration, and more effective in high-frequency transmission.

We propose a diamond-based micron-scale sensor and perform high-resolution B-field imaging of the near-field distribution of coplanar waveguides. The sensor consists of diamond crystals attached to the tip of a tapered fiber with a physical size on the order of submicron. The amplitude of the B-field component B is obtained by measuring the Rabi oscillation frequency. The result of Rabi sequence is fitted with a decayed sinusoidal. We apply the modulation-locking technique that demonstrates the vector-resolved field mapping of the micromachine coplanar waveguide structure (CPW). B-field line scan was performed on the CPW with a scan step size of 1.25 μm. To demonstrate vector resolved rf field sensing, a full field line scan acts (was performed) along four NV axes at a height of 50 μm above the device surface. The simulations are compared with the experimental results by vector-resolved measurement. This technique allows the measurement of weak microwave signals with a minimum resolvable modulation depth of 20 ppm. The sensor will have great interest in micron-scale resolved microwave B-field measurements, such as electromagnetic compatibility testing of microwave integrated circuits and characterization of integrated microwave components.

Considering the importance of increasing driving safety, the study of safety is a popular and critical topic of research in the vehicle industry. Vehicle roll behavior with sudden steering input is a main source of untripped rollover. However, previous research has seldom considered road excitation and its coupled effect on vehicle lateral response when focusing on lateral and vertical dynamics. To address this issue, a novel method was used to evaluate effects of varying road level and steering wheel input on vehicle roll behavior. Then, a 9 degree of freedom (9-DOF) full-car roll nonlinear model including vertical and lateral dynamics was developed to study vehicle roll dynamics with or without of road excitation. Based on a 6-DOF half-car roll model and 9-DOF full-car nonlinear model, relationship between three-dimensional (3-D) road excitation and various steering wheel inputs on vehicle roll performance was studied. Finally, an E-Class (SUV) level car model in CARSIM® was used, as a benchmark, with and without road input conditions. Both half-car and full-car models were analyzed under steering wheel inputs of 5°, 10° and 15°. Simulation results showed that the half-car model considering road input was found to have a maximum accuracy of 65%. Whereas, the full-car model had a minimum accuracy of 85%, which was significantly higher compared to the half-car model under the same scenario.