Creeping mode pump displacement control method based on optimal overall efficiency

Abstract

The invention discloses a creeping mode pump displacement control method based on optimal overall efficiency. The creeping mode pump displacement control method based on optimal overall efficiency aims to solve the problem that variable pump displacement is controlled when a wheel hub hydraulic vehicle is in a creeping mode to coordinate with an engine to control so as to ensure that system overall efficiency is optimal. The creeping mode pump displacement control method based on optimal overall efficiency is based on a wheel hub hydraulic hybrid power system, the hydraulic system swash plateopening degree is determined according to the current creeping speed, then engine working point under the corresponding opening degree is obtained, and the golden mean algorithm is used for iteratively searching for the optimal swash plate opening degree and the optimal engine working point. The creeping mode pump displacement control method based on optimal overall efficiency comprises the following steps that1, the variable pump swash plate opening degree search region is determined; 2, engine demand power is determined; 3, the engine working point is searched for; 4, the target optimizationfunction is set; and 5, solution is obtained through iterating refinement.

Description

technical field [0001] The invention relates to a displacement control method of a peristaltic mode pump based on optimal overall efficiency, more precisely, the invention relates to a displacement control method of a hub hydraulic variable pump. Background technique [0002] Different from the oil-electric hybrid system, the in-wheel hydraulic hybrid system is a typical type of strongly nonlinear, time-varying electromechanical-hydraulic coupling control system, and the response characteristics of the hydraulic transmission components of the front wheels and the mechanical transmission components of the middle and rear wheels are significantly different. At the same time, affected by the complex operating conditions of heavy-duty commercial vehicles and the characteristics of large-scale changes in load, the dynamic control quality of the in-wheel hydraulic hybrid system is difficult to guarantee. On the one hand, the driving force control between the hydraulic transmission ...

AI Technical Summary

Problems solved by technology

[0006] The invention aims to solve the problems of controlling the displacement of the variable pump to meet the driving load demand of the whole vehicle when the in-wheel hydraulic vehicle is in creep mode, and coordinating the engine control to ensure that the engine and the hydraulic transmission system work in the high-efficiency zone. The optimal pump displacement control method in creeping mode, based on the current crawling speed, determines the swash plate opening of the hydraulic system, and then solves the engine operating point under the corresponding opening, uses the golden section algorithm to iteratively search for the optimal swash plate opening and Optimum operating point of the engine

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