Abstract: Defect detection method for a semi-conducting bedding layer of a power cable includes: obtaining a length parameter, a corrugation pitch parameter, radius parameters, and a thickness parameter of a power cable; obtaining a first resistance value between a shield and a corrugated sheath, and calculating a second resistance value of the shield based on the length parameter and the corrugation pitch parameter; calculating a radial resistance value of the semi-conducting bedding layer based on the first resistance value and the second resistance value; determining a contact angle of a critical point of contact between the corrugated sheath and the semi-conducting bedding layer based on the radius parameters and the thickness parameter; calculating volume resistivity of the semi-conducting bedding layer based on the radial resistance value and the contact angle; and comparing the volume resistivity with a preset evaluation parameter to obtain a defect detection result of the semi-conducting bedding layer.

Abstract: A cross-coupling control method for moving beam of gantry machine tool is disclosed, which relates to the technical field of CNC machine tool control. The cross-coupling control method includes: Step 1: establishing a crossbeam dynamics model considering a ram on the crossbeam, and at the same time simplifying the model for an observer design; step 2: realizing a PID control parameter adjustment of motors at both ends in accordance with a method of parameter tuning of a unilateral servo control system; using a servo system with the same control parameters to jointly drive the crossbeam up and down, realizing the synchronous control and realizing PID control parameter tuning for both end motors. The disclosure not only reduces the synchronization error caused by the torsion of the crossbeam, but also solves the synchronization error caused by the asymmetric load on both sides, and improves the system robustness and stability.