Intelligent diesel engine cylinder balance adjusting algorithm based on approximate dynamic planning

Abstract

The invention discloses an intelligent diesel engine cylinder balance adjusting algorithm based on approximate dynamic planning. The instant rotation speed of a four-cylinder diesel engine is sampled, the modulus sum being zero of first-order harmonic waves and second-order harmonic waves of discrete Fourier transform results of rotation speed data on a working circulation of the diesel engine serves as an optimization objective, a utility function is designed, input and output control variables are selected, an approximate dynamic planning controller is designed, and through learning, the oil spray amount of four cylinders of the diesel engine is self-adaptively adjusted to compensate for the torque differences of the cylinders, so that the four periodical waveforms on the working circulation of the diesel engine tend to be identical, and the rotation characteristic is stable. By the adoption of the algorithm, the oil spray amount of the cylinders of the diesel engine can be intelligently adjusted within a certain range to compensate for the rotation speed differences, caused by uncertain factors such as device differences, parameter changes, aging and abrasion, of the cylinders, and therefore the cylinder balancing effect is self-adaptively improved.

Description

technical field [0001] The invention relates to the technical field of diesel engine intelligent control, in particular to an intelligent adjustment algorithm for diesel engine cylinder balance based on approximate dynamic programming. Background technique [0002] The characteristics of the diesel engine firing and pumping gas according to the order of each cylinder determine that its speed presents a normal periodic fluctuation in the shape of a sine wave. However, due to the device differences among the cylinders, time-varying parameters, unbalanced aging and wear, etc., it will cause unbalanced torque output among the cylinders during use, and cause the rotational speed to present an unbalanced sine wave shape periodic fluctuation, Even affect the stability of diesel engine speed. However, for the speed control of diesel engines, we have been focusing on its long-term speed value, such as the idle speed setting value of 800r / min; while the speed fluctuation between cyli...

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Problems solved by technology

However, the PID method is not efficient for nonlinear multiple-input multiple-output coupling systems; the mechanical balance device is the basis of cylinder balance, but it cannot finely compensate the differences between cylinders, and does not have the ability of self-adaptive adjustment; while other methods generally need to add expensive Additional devices such as sensors and special detection systems also need to calculate the difference between each cylinder in a complicated way; the key point is that the above methods lack the ability to intelligently adjust, which is very necessary in the current era of vigorous development of the global industry and entering the era of Industry 4.0 and intelligent manufacturing. It is also very urgent to further enhance the intelligent competitiveness of my country's diesel engine industry

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