85results about How to "Guaranteed extraction accuracy" patented technology

The invention relates to a semi-automatic antarctic subglacial lake recognition method based on an ice radar technology. The semi-automatic antarctic subglacial lake recognition method based on the ice radar technology has the advantages that in consideration of the characteristics that the interface between a subglacial lake and ice on an ice radar fracture surface image has high echo signal intensity and is flat, the initial computer recognition of a subglacial lake surface is realized by using an automatic extraction method in which the surface roughness and the radar reflection power are combined, so that the recognition efficiency and the recognition accuracy are greatly improved; the location of a subglacial lake is corrected through manual modification, no excessive workload is increased, errors caused by automatic extraction can also be made up, so that the final recognition result is relatively accurate, and the speed and the reliability are relatively high.

The invention provides an unbalance excitation force compensation method of an LMS adaptive filtering bearingless motor. The method comprises the following steps: firstly, measuring the rotating mechanical angular velocity Omegar and the real-time radial displacement x(k) of a motor rotor, and constructing dual reference signals of an LMS filter according to the Omegar and the x(k); inputting the x(k) and the dual reference signals into the LMS filter, adjusting the weight of the filter by use of a weight adjustment algorithm containing a simple step length factor adjustment function, and extracting the optimal estimation value of an unbalance vibration displacement signal of the rotor; and performing rotor synchronous revolution transformation, closed-loop feedback and inverse rotor synchronous revolution transformation on the optimal estimation value in sequence, thereby obtaining an unbalance vibration compensation control force signal. The adaptive variable-step length factor adjustment function is capable of adjusting a critical tracking error absolute value between the adaptive fast adjustment stage and the slow adjustment stage of the step length factor by use of a parameter c. The unbalance excitation force compensation method is small in calculation amount, and capable of overcoming unbalance centrifugal excitation force generated due to the mass eccentricity of the rotor; as a result, the suspension control accuracy of the rotor and the unbalance displacement tracking extraction and convergence rates are increased.