Engine rail press precontrol and feedback control device as well as control system and control method

Abstract

The invention provides an engine rail press precontrol and feedback control device as well as a control system and a control method. In the device, an ECU (electronic control unit) is connected with a constant current control unit, the constant current control unit is respectively connected with a high-pressure oil pump fuel gauging unit, a PWM (pulse width modulation) drive unit and a signal processing unit, the signal processing unit is connected with the ECU, and the ECU is connected with the PWM drive unit. The control system comprises a rail press precontrol module and a rail press feedback control module, wherein the rail press precontrol module is used for calculating the current value corresponding to the targeted rail press under the specific engine working condition; and the rail press feedback control module is used for realizing the feedback control on the targeted rail press by adjusting the PWM driving pulse duty cycle. In the method, the current value corresponding to the targeted rail press under the specific engine working condition can be calculated and then divided into two parts, wherein one part of current can be sent to the constant current control unit by the ECU and the other part of current can be added to feedback current in order to realize the feedback control on the targeted rail press by adjusting the PWM driving pulse duty cycle. The invention has the characteristics of fast response time, good following performance and precise control.

Description

technical field [0001] The invention relates to the field of power system control, in particular to an engine rail pressure pre-control and feedback control device, control system and control method. Background technique [0002] Usually the rail pressure control logic mainly includes the following parts: actual rail pressure measurement and filtering, rail pressure control target value calculation, rail pressure controller PID design, rail pressure control state machine design, rail pressure control actuator output control, etc. The basic idea is: according to the actual measurement of the rail pressure value through a suitable filter algorithm as the feedback value of the closed-loop control; calculate the rail pressure control deviation as the PID input, and the output of the controller determines the output flow of the high-pressure oil pump, which is similar to the high-pressure oil pump properties are linked. The high-pressure oil pump mainly uses PWM control to contr...

AI Technical Summary

Problems solved by technology

The current closed-loop control mode based on the software method is always difficult to quickly and accurately follow the target current

[0006] The algorithm involves the setting of the standard resistance of the control valve of the oil metering unit. Since the temperature of the control valve environment varies greatly, the ambient temperature of the control valve varies greatly from the start-up process to the high-load work process, and the actual control valve resistance always deviates from The set standard resistance, and the deviation value is always fluctuating, which will inevitably affect the performance of the rail pressure controller under different working environments

At the same time, due to the limitation of processor interrupt delay and computing power, the software control method has a long response cycle and slow response of current following control, so that the rail voltage pre-control cannot achieve the best effect

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