2results about How to "Compensation deviation" patented technology

This invention discloses a control method and system for indirectly obtaining commutation signals based on BLDC terminal voltage, belonging to the field of brushless DC motor positionless control. The method includes: sampling the voltage of the floating phase at the current commutation point after a set electrical angle; sampling the voltage of the floating phase at the next detected zero-crossing point after the current commutation point; calculating the actual zero-crossing time using the linear relationship between the back electromotive force of the first and second sampling points; obtaining the lag compensation time from the zero-crossing point to the commutation point by combining the difference between the actual and detected zero-crossing times and the commutation reference time delay; sampling the same floating phase at an electrical angle interval of α after the current commutation point and at an electrical angle interval of (60°-α) after the turn-off point, summing the two samples, and determining whether the commutation is leading or lagging based on the result; and using a PI regulator to correct the lag compensation time in a closed loop. This invention is simple, practical, and can accurately obtain the commutation signal.

This invention belongs to the field of non-destructive testing technology for concrete structures, and particularly to a non-destructive testing detection device for road and bridge structures. It includes a mounting box, two arc-shaped plates, a support adjustment assembly, a trajectory adjustment assembly, a non-destructive testing unit, and a support drive assembly. The two arc-shaped plates are symmetrically arranged on the mounting box. The support adjustment assembly is located on the mounting box and connected to the two arc-shaped plates, used for supporting the two arc-shaped plates and adjusting their angle. The trajectory adjustment assembly is located on the two arc-shaped plates and is symmetrically arranged, used to adjust the movement trajectory of the device along the outer side of the column to be tested. The non-destructive testing unit is located on the front side of the mounting box. This invention has a reasonable design, a compact overall structure, and flexible operation, completely solving the technical problems of low efficiency, high risk, and inconvenient data recording associated with traditional manual high-altitude testing. It significantly improves the automation level and operational safety of non-destructive testing of road and bridge columns.