Optimization of parameters of the mobile machine adaptive hydraulic circuit

Abstract

: Mobile machine hydraulic circuits tend to adopt electrohydraulics. Such hydraulic circuits are based on controlled pumps, modulated hydraulics, sensors and controllers. This allows adapting the hydraulic circuit operating modes to the changes of external conditions of the machine operation. Application of hydraulic circuits with electrohydraulics in mobile machines allows to use mobile machines efficiently with a high number of removable endangers, increases their performance and improves the quality of performed works. The authors propose an adaptive hydraulic circuit for a mobile machine. The operation process in the adaptive hydraulic circuit in static and dynamic modes is determined by the interaction of the pump controller and pressure differential control valves. The hydraulic system operation stability, its fast response and readjustment are determined by the controller parameters. It has been revealed that the main parameters affecting the dynamic characteristics of the hydraulic system are: throttle area 𝑓0 and coefficient of 𝑘𝑧 amplifying the pump controller orifice, dampener area 𝑓2 and coefficient of 𝑘𝑦 amplifying the pressure differential control valve orifice. These parameters affect the stability, controlling and readjustment time in the hydraulic circuit differently. A functional including the values of controlling time 𝑡𝑝, σ controlling and losses 𝑁𝑦 in the pump controller was used as an optimization criterion. The optimization has been made according to the developed mathematical model applying the method developed by I. Sobol and R. Statnikov. During the optimization each controller parameter changed on 3 levels. 81 tests were made and the best combination of controller parameters for the optimization criterion was determined. The following hydraulic circuit operation values were reached under the optimal values of parameters 𝑓0= 1.0·10-6 m2 , 𝑘𝑧= 1.0·10-3 m, 𝑓2= 1.2·10-6 m2 , 𝑘𝑦 = 10·10-3 m: 𝑡𝑝= 1.1 с, σ = 32 %, 𝑁𝑦 = 0.82 kW that comply with the requirements towards hydraulic circuits of mobile machines.