V-Type Engine Common Rail Pressure Control
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Solution Overview
Problem
Load reduction in V-type internal combustion engines with closed-loop pressure and speed control systems is difficult due to dynamics and differing step response times, as existing methods are limited to closed-loop pressure control systems of the first design.
Innovation Solution
Independent automatic pressure control for each side of the common rail system using separate closed-loop pressure control systems, where a common set rail pressure is set as a reference, and a common disturbance variable is computed to correct the pressure controllers, leveraging the higher dynamics of the closed-loop speed control system to shorten step response times during load reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single closed-loop pressure control system is used for both rails in a V-type engine, then the system complexity is reduced, but the response time during load reduction is insufficient and the control is difficult
Solution Approach 1:
The patent divides the common rail system into two independent closed-loop pressure control systems, one for each rail (A-side and B-side). Each system independently controls its respective rail pressure, allowing separate optimization of control parameters and faster response times during load reduction events without increasing overall system complexity.
2Ease of operation
If the high-pressure pump is controlled by a single input control variable, then the system is easier to operate, but the response time during load reduction is delayed
Solution Approach 1:
The patent implements dynamic disturbance variables that are computed based on the difference between set and actual rail pressures. These dynamic variables are fed back to the pressure controllers in real-time, enabling the system to adapt quickly to load changes while maintaining ease of operation through automated control.
3Loss of time
If separate closed-loop pressure control systems are used for each side, then the response time and stability are improved, but the system complexity increases
Solution Approach 1:
The patent merges the two independent pressure control systems through a common disturbance variable computation that uses the set injection quantity from the speed controller. This shared computational element coordinates both systems without requiring separate complex control logic, thus improving response time while limiting the increase in system complexity.
4Stability of the object's composition
If the pressure controller uses a standard feedback loop, then the system is stable, but the response time during load reduction is delayed
Solution Approach 1:
The patent computes disturbance variables in advance based on the set injection quantity from the speed controller, before the pressure deviation actually occurs. This preliminary computation of expected disturbances allows the pressure controller to proactively adjust, reducing the step response time while maintaining stability through the structured feedback loop.
Data Source
AI summary
A method for automatically controlling the pressure of a common rail system on an A side and a common rail system on a B side of a V-type internal combustion engine, in which the rail pressure (pCR(A)) of the common rail system on the A side is automatically controlled by an A-side closed-loop pressure control system, and the rail pressure (pCR(B)) of the common rail system on the B side is automatically controlled by a B-side closed-loop pressure control system. The automatic control of each side is independent of the other. A common set rail pressure is set as a reference input for both closed-loop pressure control systems. A set injection quantity is computed by a speed controller as a function of an actual speed relative to a set speed, and a common disturbance variable is computed as a function of the set injection quantity. Both the correcting variable of the A-side pressure controller and the correcting variable of the B-side pressure controller are corrected by the common disturbance variable.