JP2017150954A - Engine bench system control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an engine to be started in a short time in an engine bench system for measuring various characteristics of an engine by control of a dynamometer.SOLUTION: An engine bench system control device of the present invention comprises: an engine torque estimation unit 100 for finding the estimated value of engine torque on the basis of axial torque detection signal for torsion between a dynamometer and an engine and a dynamometer revolution speed detection signal; a simulated engine characteristic unit 201 for subtracting a set simulated engine loss (simulated engine loss gain model 221) from the obtained estimated value of engine torque and thereby finding an engine revolution speed signal compensated for a rotational loss of the engine; and a speed control unit 300 for generating a torque current command value (Tref) on the basis of a difference signal between the obtained engine revolution speed signal and the dynamometer revolution speed detection signal, the dynamometer being controlled through an inverter by the generated torque current command value.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a control device for an engine bench system that measures various characteristics of an engine by connecting an engine and a dynamometer and controlling the dynamometer.

  A mechanical configuration example of a conventional engine bench system is shown in FIG. In FIG. 4, an engine 1 as a specimen is connected to a dynamometer 5 through a clutch 2, a manual transmission 3 and a propeller shaft 4.

  Reference numeral 6 denotes a shaft torque meter (shaft torque detector) that detects a shaft torque formed by a twist between the engine 1 and the dynamometer 5, and reference numeral 7 denotes an incremental encoder (rotation number detector) that detects the rotation speed of the dynamometer 5. ).

  The throttle opening of the engine 1 is controlled by a throttle actuator (not shown).

  A control unit (not shown) generates an inverter torque command signal for controlling the shaft torque and the speed based on the shaft torque detected by the shaft torque meter 6 and the rotational speed detected by the incremental encoder 7, The dynamometer 5 is controlled via (not shown).

  While performing shaft torque control and speed control of the dynamometer 5, performance tests such as durability, fuel consumption, and exhaust gas measurement of the engine 1 are performed.

  The control unit realizes starting corresponding to the engine alone in a state where the engine 1 and the dynamometer 5 are connected. As a prior art, the control method having a resonance suppression effect described in Patent Document 1 is used. There is a method of applying the shaft torque command value to 0 Nm and starting the engine.

Japanese Patent No. 4766039

  In the engine bench system including the clutch 2 as shown in FIG. 4 in the mechanical configuration, the torsional resonance frequency of the mechanical system is close to the idling speed of the engine 1.

  In Patent Document 1, the dynamometer is controlled so that torsional resonance does not occur. However, depending on the combination of the engine inertia, the dynamometer inertia, and the dynamometer rated torque, the effect of suppressing the engine vibration torque at the start of the engine is reduced. As a result, torsional resonance occurs.

  As a result, as shown in FIG. 5 showing an example of the engine speed waveform at the time of starting the engine, the cranking state of the engine may continue for a long time and the engine may not be started.

  The present invention solves the above-described problems, and an object of the present invention is to provide an engine bench system control apparatus that can start the engine in a short time without the influence of engine rotation loss at the time of engine start. .

The engine bench system control device according to claim 1 for solving the above-described problem is provided.
In an engine bench system that measures various characteristics of the engine by connecting the engine and the dynamometer and controlling the dynamometer,
Based on the shaft torque detection signal formed by the twist between the dynamometer and the engine detected by the shaft torque detector, and the rotational speed detection signal of the dynamometer detected by the rotational speed detector, the engine at the time of starting the engine An engine torque estimator for obtaining an estimated value of engine torque in consideration of the rotation loss of
An engine that compensates for engine rotation loss by subtracting a set simulated engine loss for compensating engine rotation loss at the time of engine start-up from the estimated value of engine torque obtained by the engine torque estimating unit A simulated engine characteristic part for obtaining a rotation speed signal of
A speed control unit that generates a torque current command value based on a difference signal between the engine speed signal obtained by the simulated engine characteristic unit and the engine speed detection signal of the dynamometer,
The dynamometer is controlled through an inverter according to the generated torque current command value.

A control device for an engine bench system according to claim 2 is the control device according to claim 1,
The engine torque estimating unit
A shaft torque detection estimated torque calculation unit that calculates the shaft torque detection estimated torque by passing the shaft torque detection signal through a low-pass filter having a frequency band of engine torque to be estimated as a cutoff frequency;
An engine acceleration torque estimator for calculating a torque used for engine acceleration by multiplying a signal obtained by pseudo-differentiating the rotational speed detection signal of the dynamometer with a set engine inertia gain;
An engine for calculating the engine loss torque by multiplying the signal obtained by passing the rotation speed detection signal of the dynamometer through a low-pass filter having the estimated engine torque frequency band as a cutoff frequency by the set engine rotation loss gain. A loss estimator;
An addition unit that adds outputs of the shaft torque detection estimated torque calculation unit, the engine acceleration torque estimation unit, and the engine loss estimation unit;
The simulated engine characteristic section is
A simulated engine inertia unit that outputs a rotation speed signal of the engine by giving a set simulated engine inertia amount to the output of the addition unit;
A simulated engine loss model that sets a simulated engine loss torque for the output signal of the simulated engine inertia part;
And a subtracting section that subtracts the output of the simulated engine loss model from the output of the adding section and outputs the subtracted output to the simulated engine inertia section.

A control device for an engine bench system according to claim 3 is the control device according to claim 2,
The simulated engine loss model is characterized by multiplying an output signal of the simulated engine inertia unit by a simulated engine loss gain.

  According to the above configuration, the engine torque that takes into account the engine rotation loss at the time of engine start is estimated, and the simulated engine loss amount that compensates for the engine rotation loss at the time of engine start is subtracted from the estimated engine torque. Therefore, the engine rotation loss is not affected, and the engine can be started in a short time.

  Further, the engine rotational speed waveform can be arbitrarily adjusted by arbitrarily setting the simulated engine inertia part, the simulated engine inertia amount in the simulated engine loss model, and the simulated engine loss torque.

The engine bench system control device according to claim 4 is the control device according to claim 2,
The simulated engine loss model is characterized in that the output signal of the simulated engine inertia part is passed through a non-linear table in which the relationship of engine loss torque with respect to engine speed is set.

  According to the above configuration, since the simulated engine loss model is composed of a non-linear table, it is possible to simulate an arbitrary loss torque characteristic corresponding only to the engine speed.

(1) According to the first to fourth aspects of the invention, the effect of suppressing the engine vibration torque at the time of starting the engine caused by the combination of engine rotation loss, engine inertia, dynamometer inertia, and dynamometer rated torque The influence of the occurrence of torsional resonance due to the reduction is eliminated, and the engine can be started in a short time.

Further, the engine rotational speed waveform can be arbitrarily adjusted by arbitrarily setting the simulated engine inertia part, the simulated engine inertia amount in the simulated engine loss model, and the simulated engine loss torque.
(2) According to the invention described in claim 4, it is possible to simulate an arbitrary loss torque characteristic corresponding to only the engine speed.

The block diagram of the control apparatus of the engine bench system by Example 1 of this invention. The block diagram of the control apparatus of the engine bench system by Example 2 of this invention. The engine speed waveform figure at the time of the engine start by this invention. The block diagram which shows the machine structural example of an engine bench system. The engine speed waveform figure at the time of the engine start by a prior art.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments.

  FIG. 1 shows a control apparatus according to a first embodiment, which is applied to the engine bench system having the configuration shown in FIG.

  In FIG. 1, reference numeral 100 denotes an engine based on the shaft torque detection signal SHT detected by the shaft torque meter 6 of FIG. 4 and the rotational speed detection signal DYω of the dynamometer 5 detected by the incremental encoder 7 of FIG. This is an engine torque estimating unit for obtaining an estimated value (EGT) of engine torque that takes into account the engine rotation loss at the time of starting, and is specifically configured as follows.

  That is, the input shaft torque detection signal SHT has a low-pass filter LPFt (cut-off frequency ωc [rad / s]) having a transfer function of 1 / {(1 / ωc) s + 1} (s is a Laplace operator). The shaft torque detection estimated torque calculation unit 110 calculates the shaft torque detection estimated torque.

  The input rotational speed detection signal DYω of the dynamometer 5 is passed through a pseudo-differential (s * LPFω) block 121 having a transfer function of s / {(1 / ωc) s + 1}, and then the engine inertia gain block 122 is pre- By multiplying the set engine inertia (EGJ) gain, the torque used for engine acceleration is estimated (calculated).

  In this embodiment, the pseudo differential block 121 and the engine inertia gain block 122 constitute the engine acceleration torque estimation unit 120.

  The rotation speed detection signal DYω is passed through a low-pass filter (LPFω) 131 having 1 / {(1 / ωc) s + 1} (s is a Laplace operator) as a transfer function, and then the engine loss gain block 132 is preset. The engine loss torque is obtained by multiplying the engine loss (EGC) gain.

  In this embodiment, the engine loss estimation unit 130 is configured by the low-pass filter 131 and the engine loss gain block 132.

  The outputs of the detected shaft torque estimated torque calculation unit 110, the engine acceleration torque estimation unit 120, and the engine loss estimation unit 130 are added by the adding unit 140, and an estimated value of the engine torque is output.

  It should be noted that ωc (cut-off frequency) in the transfer functions of the shaft torque detection estimated torque calculation unit 110, the pseudo differential block 121, and the low-pass filter 131 is within the frequency band [rad / s] of the engine torque to be estimated. Specify (set).

Here, the equation of motion between the engine 1 and the shaft torque meter 6 of the engine bench system shown in FIG.
EGJ * s * EGω + EGC * EGω = EGT−SHT (1)
(S is a Laplace operator).

The definition of each parameter of the equation (1) is EGJ = engine inertia [kg. m ² ], EGω = engine speed [rad / s], EGC = engine loss [N. m. s / rad], EGT = engine torque [N. m], SHT = shaft torque [N. m].

At this time, the equation (1) is
EGT = SHT + EGJ * s * EGω + EGC * EGω (2)
Therefore, the engine torque can be estimated from the shaft torque detection (SHT) and the engine speed (EGω).

  However, since the engine speed is equal to the dynamometer speed in the low frequency band, the engine speed EGω is replaced with the dynamometer speed (rotation speed detection signal DYω) as in the engine torque estimation unit 100 of FIG. Further, the engine torque (EGT) can be estimated by replacing the differential operation (d / dt) with a pseudo differential (pseudo differential block 121).

  That is, the SHT in the above equation (2) is estimated by passing the shaft torque detection signal through the low-pass filter LPFt of the estimated torque calculation unit 110 for the detected shaft torque using the estimated engine torque frequency band as a cutoff frequency. The

  Further, EGJ * s * EGω in the equation (2) is obtained by multiplying a signal obtained by pseudo-differentiating the rotation speed detection signal (DYω) of the dynamometer 5 by the engine acceleration component torque estimation unit 120 by a set engine inertia gain. Presumed.

  EGC * EGω in Expression (2) is a signal obtained by passing the engine speed estimation signal (DYω) of the dynamometer 5 through a low-pass filter LPFω having the estimated engine frequency band as a cutoff frequency in the engine loss estimation unit 130. Is multiplied by the set engine rotation loss gain.

  Next, 201 in FIG. 1 subtracts a set amount of simulated engine loss for compensating for engine rotation loss at the time of engine start from the estimated value of engine torque obtained by the engine torque estimating unit 100. This is a simulated engine characteristic unit for obtaining an engine speed signal that compensates for the engine rotational loss, and functions as a parameter setting unit for adjusting the engine start waveform, and is specifically configured as follows. .

  That is, 210 gives the set simulated engine inertia amount to the output signal (estimated engine torque) of the adding unit 140 and introduced through the subtracting unit 230, which will be described later, to rotate the engine. It is a simulated engine inertia part for calculating a number signal.

  The simulated engine inertia unit 210 has a transfer function of 1 / {(EGmJ) s} (EGmJ is a simulated engine inertia model to be set and s is a Laplace operator), and the output of the subtractor 230 is (EGmJ) The engine speed signal is calculated by dividing by s.

  Reference numeral 221 denotes a simulated engine loss gain model as an embodiment of the simulated engine loss model of the present invention, which sets a simulated engine loss torque for the output signal of the simulated engine inertia unit 210 (corresponding to engine torque loss). Multiply by simulated engine loss gain. This simulated engine loss gain (EGmC) is set to, for example, a simulated engine loss for compensating for an engine rotation loss when the engine is started.

  Since the simulated engine loss gain model 221 is a gain block, the engine loss torque that can be simulated has a linear relationship represented by (loss torque) = [EGmC] * (engine speed).

  Reference numeral 230 denotes a subtracting unit that subtracts the output of the simulated engine loss gain model 221 from the output of the adding unit 140 and outputs the subtracted output to the simulated engine inertia unit 210.

  In this way, the engine torque estimated by the engine torque estimating unit 100 is subtracted from the simulated engine loss (the output of the simulated engine loss gain model 221). The rotation speed signal can be output.

  The engine characteristics in the simulated engine characteristics section 201 (the simulated engine inertia model EGmJ in the simulated engine inertia section 210 and the simulated engine loss model EGmC in the simulated engine loss gain model 221 are set arbitrarily, and the simulated engine loss model When a value larger than the engine loss EGC of the engine loss gain block 132 is set in EGmC, the engine speed at the start when a certain friction characteristic is applied to the engine 1 is calculated.

  Further, when the value of the simulated engine inertia model EGmJ is made larger than the value of the engine inertia EGJ of the engine inertia gain block 122, the engine speed at the start when some inertia characteristic is applied to the engine 1 is calculated. The

  Next, 300 inputs the engine speed signal output from the simulated engine characteristic unit 201 as the engine speed command value ωref, and inputs the engine speed detection signal DYω of the dynamometer 5 as the engine speed detection value ω. A speed control unit (DYASR) that generates and outputs a torque current command value Tref with zero difference.

  Tref generated by the speed control unit 300 is used as a torque current command (DYTref) to an inverter (not shown), and the rotational speed of the dynamometer 5 is controlled.

  As a result, a desired engine start that simulates the engine characteristics (simulated engine inertia model EGmJ, simulated engine loss gain (EGmC)) set by the simulated engine characteristic unit 201 is realized.

  In the first embodiment, the simulated engine loss model (EGmC) of the present invention is configured by the simulated engine loss gain model 221 of FIG. 1, but in the second embodiment, instead of this, the simulated engine characteristic unit 202 shown in FIG. The non-linear table 222 is used.

  The non-linear table 222 in FIG. 2 is a table of the relationship of the engine loss torque to the engine speed, and the engine corresponding to the engine speed corresponding to the engine speed is input using the output of the simulated engine inertia unit 210 (engine speed signal). The loss torque is output to the subtractor 230, and the other parts are configured in the same manner as in FIG.

  Thus, since the simulated engine loss gain model 221 of the first embodiment is a gain block, the engine loss torque that can be simulated is a linear relationship represented by (loss torque) = [EGmC] * (engine speed). However, in the second embodiment, since the simulated engine loss model EGmC is configured by a non-linear table, an arbitrary loss torque characteristic corresponding to only the engine speed of (loss torque) = f (engine speed) is simulated. be able to.

  FIG. 3 shows an engine speed waveform when the engine is started when the control circuit (FIG. 1) of the present invention is applied to the engine bench system of FIG.

  FIG. 3 shows starting waveforms with four types of engine simulation characteristics obtained by changing the simulated engine inertia model EGmJ of the simulated engine inertia unit 210 and the simulated engine loss model EGmC of the simulated engine loss gain model 221.

That is, the waveform A is EGmJ = 0.2 [kg. m ² ], EGmC = 0 [N. m. s / rad], and the waveform B is EGmJ = 0.2 [kg. m ² ], EGmC = 0.05 [N. m. s / rad] and the waveform C is EGmJ = 0.2 * 1.2 [kg. m ² ], EGmC = 0 [N. m. s / rad], and the waveform D is EGmJ = 0.2 * 0.8 [kg. m ² ], EGmC = 0 [N. m. s / rad].

  In starting the engine according to the prior art, as shown in FIG. 5, it takes a long time to get out of the cranking state. However, according to the present invention shown in FIG. It can be seen that has started.

  As described above, the control device according to the present invention not only enables the engine to be started in a short time, but also adjusts the simulated engine characteristic parameters (simulated engine inertia model EGmJ, simulated engine loss model EGmC), thereby rotating the engine. It is also possible to adjust several waveforms.

DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Clutch 3 ... Manual transmission 4 ... Propeller shaft 5 ... Dynamometer 6 ... Shaft torque meter 7 ... Incremental encoder 100 ... Engine torque estimation part 110 ... Shaft torque detection estimated torque calculation part 120 ... Engine acceleration torque Estimating unit 121 ... pseudo differential block 122 ... engine inertia gain block 130 ... engine loss estimating unit 131 ... low-pass filter 132 ... engine loss gain block 140 ... adding unit 201, 202 ... simulated engine characteristic unit 210 ... simulated engine inertia unit 221 ... simulation Engine loss gain model 222 ... Nonlinear table 230 ... Subtraction unit 300 ... Speed control unit

Claims (4)

In an engine bench system that measures various characteristics of the engine by connecting the engine and the dynamometer and controlling the dynamometer,
Based on the shaft torque detection signal formed by the twist between the dynamometer and the engine detected by the shaft torque detector, and the rotational speed detection signal of the dynamometer detected by the rotational speed detector, the engine at the time of starting the engine An engine torque estimator for obtaining an estimated value of engine torque in consideration of the rotation loss of
An engine that compensates for engine rotation loss by subtracting a set simulated engine loss for compensating engine rotation loss at the time of engine start-up from the estimated value of engine torque obtained by the engine torque estimating unit A simulated engine characteristic part for obtaining a rotation speed signal of
A speed control unit that generates a torque current command value based on a difference signal between the engine speed signal obtained by the simulated engine characteristic unit and the engine speed detection signal of the dynamometer,
A control device for an engine bench system that controls the dynamometer through an inverter according to the generated torque current command value. The engine torque estimating unit
A shaft torque detection estimated torque calculation unit that calculates the shaft torque detection estimated torque by passing the shaft torque detection signal through a low-pass filter having a frequency band of engine torque to be estimated as a cutoff frequency;
An engine acceleration torque estimator for calculating a torque used for engine acceleration by multiplying a signal obtained by pseudo-differentiating the rotational speed detection signal of the dynamometer with a set engine inertia gain;
An engine for calculating the engine loss torque by multiplying the signal obtained by passing the rotation speed detection signal of the dynamometer through a low-pass filter having the estimated engine torque frequency band as a cutoff frequency by the set engine rotation loss gain. A loss estimator;
An addition unit that adds outputs of the shaft torque detection estimated torque calculation unit, the engine acceleration torque estimation unit, and the engine loss estimation unit;
The simulated engine characteristic section is
A simulated engine inertia unit that outputs a rotation speed signal of the engine by giving a set simulated engine inertia amount to the output of the addition unit;
A simulated engine loss model that sets a simulated engine loss torque for the output signal of the simulated engine inertia part;
2. The engine bench system control device according to claim 1, further comprising: a subtracting unit that subtracts an output of the simulated engine loss model from an output of the adding unit and outputs the subtracted output to the simulated engine inertia unit.   The engine bench system control device according to claim 2, wherein the simulated engine loss model multiplies an output signal of the simulated engine inertia unit by a simulated engine loss gain.   3. The engine bench system control device according to claim 2, wherein the simulated engine loss model passes an output signal of the simulated engine inertia unit through a non-linear table in which a relationship of an engine loss torque with respect to an engine speed is set.

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