Abstract: A device for measuring a diameter error of a roller for threaded pair transmission in the technical field of power machinery, comprising a roller fixing device, a laser measuring device, a screw driving device, and a roller to be measured. The roller fixing device comprises a fixing rod, a supporting structure, guide rails, nut-bolt pairs and a fixing beam, to fix the roller. The laser measuring device comprises pressing columns, laser sensors, laser receiving plates, laser sensor placement plates and moving structures, which ensure the verticality of the roller. The screw driving device comprises ball screw pairs, bearings, nuts, nut connecting bolts and cranks, to drive the moving structures to ensure the distance between the laser measuring device and the roller. The roller diameter error measuring device of the present disclosure is simple to operate, has fewer human influence factors, and has high measurement accuracy.

Abstract: A two-stage turbocharging energy-efficient self-adaptive control method based on multi-point intake and exhaust pressures in diesel engine turbocharging field, including: determining a target turbocharging pressure for plains upon diesel engine speed and load conditions; adjusting it to obtain optimal target turbocharging pressures for varying altitudes; using these and measured multi-point pressures in intake and exhaust pipelines as inputs, based on an energy utilization analysis model, to determine the two-stage turbocharging energy utilization efficiency suitable for different altitude environmental conditions; according to the optimal overall efficiency principle of the two-stage turbocharging system at variable altitudes, calculating opening degrees of the bypass valves that meets the target total pressure ratio by a valve control unit. Reasonable distribution of exhaust energy between the two-stage turbochargers is achieved.

Abstract: An intelligent variable mode control method for variable altitude turbocharging system of diesel engine, including: querying turbocharging pressure MAP chart upon speed and torque demands; reading a target pressure, and correcting it to obtain a corrected pressure; based on adaptive ranges of flow-pressure ratio of turbocharging modes, using fuzzy control algorithms to achieve intelligent selection of turbocharging modes; initializing opening degrees of high- and low-pressure stage bypass valves within adjustment ranges; using neural network fast prediction models to predict turbocharging pressures; using genetic algorithms to fast search bypass valve opening degrees corresponding the target and send them to the valve control unit.

Abstract: A diode clamp mixed three-level dual-active full-bridge converter based on a dual active full-bridge converter, an additional control variable is added by replacing two-level bridge arm on the primary side with a diode clamp three-level bridge arm. A control method based on four variables including duty ratios of 0 voltage level and high voltage level of the primary side, duty ratio of 0 voltage level of the secondary side of the diode clamp mixed three-level dual active full-bridge converter, and phase shift ratio between primary and secondary sides of the diode clamp mixed three-level DAB converter; four-degree-of-freedom globally optimized control is realized by coordinating four variables, RMS value of the current is reduced, and operating efficiency of the converter is improved. Closed-loop control of the DAB globally optimized operation is given, which enables the converter to automatically realize globally optimized operation under different operating conditions.