JP3674075B2 - Engine control method - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an engine test system using a dynamometer or an engine control method for arbitrarily controlling various parameters of the engine.
[0002]
[Prior art]
The engine has various control parameters. For example, there are many types such as cooling water temperature, lubricating oil temperature, lubricating oil pressure, ignition advance angle.
[0003]
Conventionally, when controlling the above parameters of the engine, feedback control by a PID controller is used, a control system is constructed for each control target, and the proportional gain, time constant, and soot constant of the PID matching the characteristics of the control target are set. Design and control.
[0004]
A conventional control example of the air-fuel ratio (A / F) and the exhaust temperature is shown in FIG. In the figure, 21 is a dedicated A / FPID controller for controlling the A / F of the engine 1 based on the A / F setting, and 22 is a dedicated exhaust for controlling the exhaust temperature of the engine 1 based on the exhaust temperature setting. A temperature PID controller 3 is a throttle position controller that controls a throttle actuator that operates the throttle of the engine based on a throttle opening command θset input from the PID controller 21 or 22 via the switch S1. Reference numeral 4 denotes a dynamometer coupled to the engine.
[0005]
[Problems to be solved by the invention]
In the above conventional engine control system, a manufacturer provides a dedicated controller for controlling various parameters of the engine. In such a system, it is necessary to determine and create all control points in advance, and to control a new parameter, it is necessary to add a controller each time.
[0006]
There is also a method of simply preparing a PID controller and adjusting the P, I, and D of the controller on the user side. However, since adjustment of the control system requires very precision, a desired control waveform can be easily obtained. It is not possible. Recently, some controllers other than the engine determine the P, I, and D parameters by auto-tuning, but the control of the engine parameters cannot be applied because of strong nonlinearity.
[0007]
The present invention has been made in view of such conventional problems, and an object of the present invention is to provide an engine control method capable of performing stable control with any engine parameter.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, an engine control system according to the present invention includes a deviation bandwidth monitoring circuit that compares a deviation between an engine parameter setting value and an engine parameter detection value with a predetermined deviation bandwidth and outputs a hold signal. When the deviation is larger than the deviation bandwidth, the output is held by the signal of the deviation bandwidth monitoring circuit, and when the deviation is within the deviation bandwidth, a controller with a hold that outputs a throttle command based on the deviation; When each output has a hold circuit and the deviation is larger than the deviation bandwidth, the throttle opening command input by the signal of the deviation bandwidth monitoring circuit is held, and from the hold value, a step shape is formed according to the polarity of the deviation. increased or decreased small to output a throttle opening command, deviation of the deviation band width monitoring circuit to fall within the deviation band width Its output is made and a set up control circuit to be held in issue.
[0009]
[Action]
When the deviation is larger than the deviation bandwidth, the output of the controller with hold is held by the monitoring circuit, and the control by the controller does not work. On the other hand, in this case, the throttle opening command input to the setting tracking control circuit is held by the monitoring circuit, and the throttle opening command that increases or decreases in a stepwise manner according to the polarity of deviation from the hold value is output to throttle the engine. Control the opening. In this control, since the command changes stepwise and has a waiting time, no overshoot occurs. When the deviation falls within the deviation bandwidth, the command from this circuit is held, and the hold of the controller is released, so that the control shifts to the controller.
[0010]
【Example】
Embodiments of the present invention will be described with reference to the drawings.
[0011]
In FIG. 1, 1 is an engine, 2 is a throttle actuator for the engine, 3 is a throttle position controller for controlling the actuator, 4 is a dynamometer coupled to the engine, 11 is an A / F (air / fuel ratio) of the engine, and exhaust pressure. A deviation detector that detects a deviation e between the set value of the engine parameter and the detected value and the like, 12 is a PI controller with a hold to which the deviation e is input, 13 is a deviation bandwidth with a predetermined deviation e ( for example, parameter setting) The deviation bandwidth monitoring unit for determining whether the control is in a transient state or a steady state depending on whether or not ± 5%) is exceeded, and a throttle opening (θ) command for controlling the throttle position controller 3 is input to the deviation bandwidth monitoring unit 14. A hold circuit for holding the current throttle opening (θ) command when the deviation bandwidth monitoring unit 13 detects a transition, 15 is a hall In the staircase command output unit that outputs a stepped throttle opening command from the opened opening command and the deviation e, whether the up-counting or down-counting is determined according to whether the polarity of the deviation e is positive or negative, is held. and it is configured to output a stepped throttle command by making the added latency certain steps amount.
[0012]
16 is a hold circuit that holds the staircase command from the staircase command output unit when the deviation band width monitoring unit 13 detects the inside of the deviation band, and 17 is the addition of the output of the PI controller 12 and the output of the hold circuit 16, and the throttle opening (Θ) An adder that outputs a command to the throttle position controller.
[0013]
Next, the operation of this embodiment will be described. In this control method, as shown in FIG. 2, when the deviation between parameter setting and detection is larger than a predetermined deviation band width, setting follow-up mode control is performed in which control is performed with a stepped accelerator opening command, and the deviation is within a predetermined deviation band. When the width is smaller than the width, control is performed in a steady securing mode in which PI control is performed.
[0014]
(1) Setting tracking mode
During the transition from the start of control by the parameter setting until the control is stabilized, the deviation bandwidth monitoring unit 13 detects the transition and outputs an ON signal to the PI controller 12 and the hold circuit 14. Since the deviation e at the time of starting the parameter setting is positive, the staircase command output unit 15 sends a throttle opening command that increases stepwise from the output of the hold circuit 14 via the hold circuit 16 and the adder 17 to the throttle position controller. 3 and the engine throttle opening is controlled by the throttle opening command of this staircase. That is, a circuit including the hold circuit 14, the staircase command output unit 15, and the hold circuit 16 functions as a setting tracking circuit.
[0015]
There are many types of engine parameters, some of which respond quickly to the movement of the throttle and some of which respond slowly. Since the throttle opening is increased by a step-like operation of waiting, overshoot is generated when the control is shifted from this control to the control by the PI controller, for example, when it is raised by a ramp function. Can be controlled without any problems. The amount of rise of the stairs and the waiting time of the throttle command can be set arbitrarily by adjusting the constant of the stairs command output unit, etc. Also, since it is throttle control during transition, hunting during transition, etc. There is no worry.
[0016]
When the deviation e falls within a predetermined deviation bandwidth ( for example, ± 5% of parameter setting ) that can be regarded as steady, the deviation bandwidth monitoring unit 13 detects this and switches to the steady accuracy ensuring mode.
[0017]
(2) Condition steady accuracy-ensuring mode deviation e is to be within the deviation band width, deviation band width monitoring section which outputs to the hold circuit 16 stop the output of the PI controller 12 and the hold circuit 14, and hold the stairs command output Switch to PI control by PI controller. Therefore, the mode can be changed without shock. By performing PI control, it is possible to ensure the accuracy for parameter setting.
[0018]
In this case, it is necessary to adjust P and I of the PI controller. Generally, it is difficult to adjust the PI during the transition, and this control method does not perform the PI control during the transition. Since adjustment only needs to be performed, no skill is required for PI adjustment.
[0019]
If the engine parameter setting is lowered as shown in FIG. 2 in the steady accuracy ensuring mode, for example, a negative deviation −e exceeding the determination bandwidth is generated. Therefore, the PI control is held and the staircase command output unit 15 A throttle opening command that decreases stepwise from the throttle opening (θ) command value at the time of setting switching held by the hold circuit 14 is output, and setting follow-up mode control is performed.
[0020]
【The invention's effect】
Since this invention is comprised as mentioned above, there exists an effect described below.
[0021]
(1) With respect to the engine parameter that is a non-linear control target, any parameter can be stably controlled.
[0022]
(2) No skill is required to adjust P and I of the PI controller.
[0023]
(3) Since the throttle opening control is a minor control during the transition, hunting, overshoot, etc. do not occur.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a configuration of an engine control system according to an embodiment of the present invention.
FIG. 2 is a control waveform diagram in the embodiment.
FIG. 3 is a diagram illustrating a configuration of a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Throttle actuator 3 ... Throttle position controller 4 ... Dynamometer 11 ... Deviation detector 12 ... PI controller with hold 13 ... Deviation bandwidth monitoring circuits 14, 16 ... Hold circuit 15 ... Stair command output circuit

Claims (1)

A deviation bandwidth monitoring circuit that compares the deviation between the engine parameter setting value and the engine parameter detection value with a predetermined deviation bandwidth and outputs a hold signal;
When the deviation is larger than the deviation bandwidth, the output is held by the signal of the deviation bandwidth monitoring circuit, and when the deviation is within the deviation bandwidth, a controller with a hold that outputs a throttle command based on the deviation;
When there is a hold circuit on the input and output sides and the deviation is larger than the deviation bandwidth, the throttle opening command input by the signal of the deviation bandwidth monitoring circuit is held, and from the hold value according to the polarity of deviation A setting follow-up control circuit that outputs a throttle opening command that increases or decreases in a stepwise manner, and when the deviation enters the deviation bandwidth, the output is held by the signal of the deviation bandwidth monitoring circuit;
The provided control system for an engine deviation was set following control is larger than the deviation band width, and wherein the switching controller controls when the difference is within the deviation band width.

Images