SU1576705A2 - Rotational speed governor of internal combustion engine - Google Patents

Abstract

The invention makes it possible to improve the accuracy of controlling the rotational speed. The controller contains a rotational speed sensor 1, a displacement sensor 2 of the actuating member 14 of the water-dosing unit, an identification unit 3, a block of 4 control modes, three multiplication units 5-7, two amplifiers 8 and 9, a mismatch meter 11, a correction device 12 and an adder 13. The regulator operates using the modal control principle. When the operating modes of the engine change, the identification block 3 and the block of 4 control modes, based on signals from sensors 1 and 2, generate signals of engine parameter estimates, with which the controller maintains the desired quality indicators of the control system. The lack of overshoot and the monotonous nature of the transition process provide an increase in the reliability and fuel efficiency of the engine in a wide range of its operating modes. 2 Il.

Description

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About vj

About SL

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The invention relates to the field of engine-building, in particular, to electric systems for automatic control of the rotation frequency of engines, and is an improvement of the known regulator according to the author. St. No. 1408095.

The aim of the invention is to improve the accuracy of rotational speed control when the engine operating modes vary widely.

Fig. 1 is a functional diagram of the controller; in fig. 2 - its structural scheme.

The rotational speed controller contains a rotational speed sensor 1, a displacement sensor for the fuel-servicing unit, an engine parameter identification unit 3 with two inputs and three outputs, a control mode block A with three inputs and two outputs, three multiplication units (first 5, second 6 and additional 7), two amplifiers 8 and 9, a source 10 of the master signal, a mismatch meter 11, a correction device 12, an adder 13 with three inputs and an actuating element 14 of the fuel-dispensing body of the engine 15.

Sensors 1 and 2 are connected to the engine 15. The outputs of sensors 1 and 2 are connected separately to the inputs of the identification block 3, the outputs of which are connected to the corresponding inputs of the block of 4 control modes. The outputs of the latter are connected to the following elements: the first is connected to the first input of multiplication unit 5, and the second to the first inputs of multiplication units 6 and 7. The second input of multiplication unit 6 is connected to the output of rotational speed sensor 1 and the subtractive input of the error meter 11, which by its summing input is connected to the source 10 of the master signal and the input of the amplifier 9, and the output to the input of the correction device 12. The subtractive input of the adder 13 is connected to the output the multiplication unit 6, one summing input with the output of the correction device 12, and the other with the output of the multiplication unit 7. The output of the amplifier 9 is connected to the second input of the multiplication unit 7, and the output of the adder 13 to the second input of the multiplication unit 5. The output of the latter is connected to the input of the amplifier 8, the output of which is connected to the input of the actuating element 14 of the engine's toplivocirculation body.

In addition, the following notations are used (Fig. 2): 1) s - output reference signal of source 10, Ki and K2 - gain factors of amplifiers 8 and 9

respectively; L / s (5) is the transfer function of the actuating element 14 of the fuel-supplying body; h - movement of the toplivating organ; w - frequency

engine rotation; a, b - engine parameters; Wk (S) is the transfer function of the correction device 12; Wh (S) is the transfer function of the sensor 2 for displacing the fuel-discharging organ (S) 0 the transfer function of the sensor 1 for the rotational speed; Uh is the output signal of the sensor 2 displacing the fuel-dispensing unit; (Jar the output signal of the rotational speed sensor 1; U is the control signal; b / (S-a) 5 is the transfer function of the engine (where a and b are non-linear polynomials from h and w); gGy are estimates of the parameters of the engine.

The proposed rotational frequency control works on the principle of modal control. In accordance with the principle submitted for the rotational speed control system, including the engine and the controller, described by the expressions:

(n, w) w + b (h, co) h; (one)

(5) U, synthesized control

 M (h, w) w + G (h, ct) co, (2) the stabilizing position of the dominant root of the system. The quality indicators of the control system in question, such as the transition time, the amount of overshoot, the rise time of the transition process, the system bandwidth 5, the accuracy of the master setting, are mainly determined by the position of the dominant root, i.e. a root located sufficiently close to the imaginary axis of the complex plane of the roots. Stabilizing the dominant root gives the system the property of modal invariance, i.e. allows you to provide the desired quality control unchanged throughout the range of operating modes.

The characteristic equation of the system is

) + M (h, (h, y) -1b (M О, (3) where A is the stabilized dominant Q real root.

The coefficient M (h.u) is determined from the characteristic equation (3):

M (I, y) ((AXA-a (b / o) (4),

five

0

five

/

The coefficient G (h, w) is chosen based on the required equality ftfc -or in the statics.

G (M - BH ((AXA-a (M) +

a (h, o)}

(five)

Given expressions (4) and (5), the final expression for control is obtained in the form

U, y) (W3 - ftO -a (h, w) ft + (h, w) (AXl - WM3 (A) a (h, y) W3. (6)

After replacing the parameters a and b with their estimates a and b, also replacing the variables h and ft) with the values measured by sensors 1 and 2, get the following control law implemented on the block diagram (Fig. 2)

whether (A) -A (i3-M - +

+ b-1WM3 (A) 1-W, 3 (A) aU. (7)

To implement the regulator in accordance with the law of governance (7), the following conditions must be met:

(A); K2 (A);

Wk (S) -A; W, (S)) 1, (8) as well as the speed condition of the actuator 14 exceeding the speed of the speed control loop, which is feasible in most cases encountered in practice. In this case, the regulator was synthesized taking into account the real inertia of the actuator, where the actuator was assumed to be inertia-free.

The regulator works as follows.

When the engine operating modes change, at the output of the unit 4 operating modes, the signals of the engine parameters a and o4 are formed. According to the indicated signals, the controller, using block 7 and amplifiers 8 and 9, generates a control signal at the input of the actuator 14, which provides the desired character of the transient process (no overshoot, monotonous transient process, specified transient time) when the engine parameters vary and environmental conditions, and taking into account the inertia of the executive element of the toplivodosiruyuschego body.

Claims (1)

Thus, the regulator provides an increase in the accuracy of regulation on both established and unspecified operating modes, increased reliability (due to guaranteed stability and no overshoot) and fuel efficiency (due to the absence of overshoot and monotonic nature of the transition process). Claims of the Invention Regulator of the rotational speed of an internal combustion engine according to aut. St. No. 1408095, characterized in that, in order to improve the control accuracy, it is additionally equipped with two amplifiers and a multiplication unit, and the adder is made with four inputs, the first amplifier being connected to the communication line of the first multiplication unit with the actuating element of the fuel-supplying organ, the input The second amplifier is connected to the source of the master signal, and the output is connected to one of the inputs of the additional multiplication unit, the other input of which is connected to the second output of the control mode unit, and the output is connected to the fourth input of the sums torus.