JPH01190922A - Torque controller for internal combustion engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to internal combustion engines, and in particular, to reducing torque fluctuations caused by combustion pressure fluctuations during operation, and vibrations of cylinder blocks, etc., induced by the torque fluctuations. The present invention relates to a torque control device for an internal combustion engine suitable for.

[Prior Art] Conventionally, in internal combustion engines, gas torque fluctuates due to changes in cylinder pressure due to intake compression of air-fuel mixture, expansion of combustion gas, etc., and rotational inertia changes due to changes in the angle of the connecting rod with respect to the crankshaft. It is well known that the inertia torque varies. When such torque fluctuations are transmitted by the internal combustion engine to various devices subjected to one-wheel drive, torsional vibrations occur in those devices, causing performance degradation and damage to the devices. Furthermore, this 1-
The reaction of the torque change IJ1 is transmitted from the cylinder block to the mounts and chassis that support the internal combustion engine.

Since this causes vibrations in the internal combustion engine and the entire heavy vehicle, it is necessary to sufficiently reduce the magnitude of torque fluctuations generated by the internal combustion engine.

To address this problem, conventionally, the inertial mass of the flywheel has been increased in order to reduce torsional vibration. In order to reduce vibration in an internal combustion engine, the rigidity of the engine mount is reduced to avoid resonance. Furthermore, in order to directly reduce torque fluctuations, methods such as absorbing and generating torque in synchronization with the rotation angle of the crankshaft of an internal combustion engine have been adopted, as seen in Japanese Patent Application Laid-Open No. 155626. There is.

[Problem to be solved by the invention]

However, in the above conventional technology, an increase in the inertial mass of the flywheel deteriorates the responsiveness to acceleration/deceleration of the rotational speed, and a decrease in the rigidity of the engine mount is a reaction to the large rotational torque generated by the internal combustion engine during sudden acceleration. This may actually cause the internal combustion engine to vibrate significantly.

Conventional methods for absorbing and generating torque have problems such as being unable to follow changes in torque fluctuations due to changes in internal combustion engine speed or load due to oven loop control.

The purpose of the present invention is to solve such problems, detect torque fluctuations of an internal combustion engine, and based on this torque fluctuation information,
An object of the present invention is to provide a torque control device for an internal combustion engine that can reduce torque fluctuations by controlling the torque absorbed and generated by an electric drive device provided in a main power transmission system.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a main power transmission system that operates as a generator or 'ff11! Detection means for detecting torque fluctuation components generated by the internal combustion engine for each rotation angle of the main shaft of the internal combustion engine in an internal combustion engine equipped with an electric drive device capable of operating as an II machine or as a generator and an electric motor. and a control means for controlling the torque absorbed or generated by the electric drive device based on the detected torque fluctuation component, and the control means controls the drive ΔJ device so that the torque fluctuation generated by the engine is reduced. It is characterized by changing the magnitude of the torque absorbed or generated by the engine depending on the rotation angle of the main shaft of the internal combustion engine.

[Operation] According to the above-described configuration, the torque absorbed and generated by the electric drive device is controlled in accordance with the torque fluctuations generated by the internal combustion engine, and the torque fluctuations can be significantly reduced.

〔Example〕

Embodiments of the present invention will be described below based on the drawings. 1st
In the figure, an internal combustion engine 1 includes an engine body 2, a distributor 3 with a built-in crank angle sensor, a transmission 8!4 of the main power transmission system, and an Iar! A flywheel motor generator 5, which is an example of an electric drive device, is provided between the jX1 main body 2.

The motor generator 5 can switch between operating as a generator or as an electric motor.

When the motor generator 5 operates as a generator,
If the amount of power generation (load current or field current) is increased, the torque absorbed by the motor generator 5 will increase, and if the amount of power generation is decreased, the torque absorbed can be reduced. Furthermore, when operating as an electric motor, increasing the electrical input (armature current or field current) to the motor generator 5 increases the torque generated by the motor generator, and decreasing the electrical input can reduce the generated torque. .

A control system that controls the torque absorbed or generated by the motor generator 5 includes a microcomputer 6, and upon receiving instructions from the microcomputer 6, switches the operation of the motor generator 5 to either a generator or an electric motor to control the amount of power generated per unit or electricity. It is composed of a torque control section 7 that increases or decreases the input amount.

Torque fluctuations in the internal combustion engine 1 can be detected in the form of rotational acceleration fluctuations of the crankshaft. The rotational acceleration fluctuation can be calculated based on the value measured by the timer 6a in the microcomputer 6 of the output pulse period of the crank angle sensor. The microcomputer 6 calculates the crank angle rotation angle for switching the operation of the motor generator 5 and the amount of effi or electric input required to reduce this rotational acceleration fluctuation to O, and sends a command value to the torque control unit 7. send.

FIG. 2 shows an example of rotation pulses obtained from the crank angle sensor. The crank angle sensor generates a pulse every time the crankshaft rotates by a certain angle.

Therefore, if the rotational speed of the crankshaft changes, as shown in FIG. 2, the output pulse generation period also changes.

The microcomputer 6 in FIG.

By measuring the generation period of this output pulse using the timer 6a and calculating the time differential of the reciprocal of the period using the CPU 6b, it is possible to obtain the rotational acceleration fluctuation from moment to moment (FIG. 3).

FIG. 4 specifically shows the configuration of the control circuit of the first embodiment. The motor generator 5 is.

When the generator is operating, AC power (3-phase AC in Figure 4) is output, and when the motor is operating, the stator coil (
Armature coil) 5d9 Rotor coil (field coil) 5b through which field current flows during both operations.

When the generator is operating, the AC output of the stator coil 5a is rectified into DC, and when the motor is operating, the switching element 5c, such as a thyristor, distributes and supplies armature current to each phase coil in the stator coil 5a, and the output voltage is kept constant. Self-S voltage regulator (AVR) 5d to adjust.

Switching calculated by the microcomputer 6 based on output signals from the magnetic pole position detector 5e and the magnetic pole position detector 5e, which detects the rotation angle of the rotor coil 5b in order to know the positional relationship between the stator coil 5a and the rotor coil 5b. It is composed of a pulse distributor 5f that distributes the 0N10FF command pulse of the element group to each switching element 5C.

When the rotational speed of the internal combustion engine 1 is high and the torque fluctuations generated by the engine are small and torque control is not required, the motor generator 5 operates as a generator as follows. That is, when the magnetic field created by the rotor coil 5b rotates, the motor generator 5 operates as a generator. The stator coil 5a starts generating electricity, and after being rectified into direct current by the switching element 5c which acts as a rectifier, the stator coil 5a supplies electric power to a load 8 such as a light or a heater, and a battery 9.

The output voltage of the generator is automatically adjusted by the AVR 5d changing the magnitude of the field current flowing through the rotor coil 5b.

The rotation speed of the internal combustion engine 1 is low (for example, when idling)
When the torque fluctuation generated by the engine is large, torque control as described below is performed. That is, the torque fluctuation appears as a rotational acceleration fluctuation of the crankshaft, which is detected by the crank angle sensor 3. The detected rotational pulse is
The frequency is divided into the number of pulses required for control by the frequency divider 10, and then input to the microcomputer 6, where rotational acceleration fluctuations are calculated by the method described above. 5 calculates the amount of torque that should be absorbed or generated, and the value of the load current during generator operation or armature current during motor operation necessary to absorb or generate this torque, and sends the result to the pulse distributor. 5f and the D/A converter 11 to the torque control section 7.

When the rotational acceleration fluctuation of the crankshaft is negative, that is, when the torque generated by the internal combustion engine 1 is smaller than the average torque (section B in Fig. 5), the motor generator 5 acts as an electric motor to compensate for the lack of torque. The magnitude of the zero generated torque that operates and generates torque is determined by the magnitude of the armature current flowing through the stator coil 5a, and as the armature current increases, the generated torque increases. Therefore, when the shortfall in the torque generated by the engine relative to the average torque is large, the armature current is increased to increase the torque generated by the motor generator 5, and conversely, when the shortfall is small, the armature current is decreased. This makes it possible to reduce the torque generated by the motor generator 5, thereby compensating for the portion of the torque fluctuation where the torque is insufficient. Note that the magnitude of the armature current is 0N1 of the power supply supplied to each phase coil in the stator coil 5a.
It can be changed by changing the timing (firing angle) of 0FF, that is, by controlling the phase. Specifically, this can be achieved by controlling, by the microcomputer 6, the timing at which pulses from the pulse distributor 5f are generated to be applied to each switching element 5c.

Next, when the rotational acceleration fluctuation of crank 1lil[I is positive.

That is, when the torque generated by the internal combustion engine 1 is larger than the average torque (sections A and C in FIG. 5), the motor generator 5 operates as a generator to absorb the torque in order to remove the surplus torque.

The magnitude of the absorbed torque is determined by the magnitude of the load current flowing out from the stator coil 5a, and as the load current is increased, the absorbed 1-lux increases. Therefore, when the torque generated by the engine has a large surplus with respect to the average torque,
By increasing the load current, the motor generator 5
By increasing the torque absorbed by the motor generator 5 and, conversely, reducing the load current when the surplus is small, the torque absorbed by the motor generator 5 can be reduced, thereby removing the surplus torque from the torque fluctuations. Note that the magnitude of the load current can be controlled by the method described below. That is, the driver 12 of the torque control section 7 is
The MOS switch 13 connected in parallel with the load 8 and the battery 9 is controlled 0N10FF, and the MOS switch 13
When turned on, the circuit current bypasses and flows to the MOS switch, so a large load current flows. Therefore, if the driver 12 is driven by PWM control or the like and the duty ratio of ON10FF of the MOS switch 13 is changed, the load current can be increased or decreased.

FIG. 6 is a diagram showing details of the torque control section 7. As shown in FIG. The load current iL is obtained as a voltage drop across the galvanometer resistor R517, is converted into a detected current value vtt by the amplifier 14, and then sent to the automatic current converter (ACR) 15. A.C.
Rl5 is the current command value VLg of the microcomputer 6
The feedback loop is configured so that the current detection value vi and the current detection value vi are equal.

A chopper circuit 17 that forms a chopper signal using the output of the ACRl 5 and the triangular wave oscillator 16 is configured so that the load current iL is equal to the current command value of the microcomputer 6.
The OS switch is duty-controlled by pulse width modulation (PWM) (see FIG. 7).

FIG. 8 is a diagram showing the control flow of the control circuit described above. Let N be the number of rotation pulses used for control during the engine-combustion cycle (converted to the rotation angle of the crankshaft: 720' for a 4-stroke engine, 360' for a 2-stroke engine). In step 110, when a rotation pulse (kth) at a certain crankshaft rotation angle is detected, from the period Δt with the k-1th pulse, this time Δtk For a vehicle engine, 4π/N (rad), In the case of a two-cycle engine, 2π/N (rad) can be calculated and the engine can rotate. There are many other methods for calculating Vl,,ah, but they can be selected depending on the accuracy required for control.For example, considering Δt k2Δt h−z
tk, and further assume that torque control is performed within a limited rotational speed range (for example, during idling).

It is also possible to set ak=k.(vh-vk-t) (k is a constant).

Next, in step 120, it is determined whether a generator operation or an electric motor operation was being performed one cycle before.8 If the generator operation was being performed, the process moves to step 130;
Rotational acceleration change #J a h newly obtained in step 110
Using, load current command ik is 1h=ih+ka' a
h (kn is a positive constant). Correct in the form of (1). (
According to equation 1), when there is a surplus in the torque generated by the engine, that is, when ak>O, the absorbed torque is increased by increasing lk, and when there is a shortage of torque, that is, when ak When <O, ik is decreased to make the absorbed torque smaller, so the load current command 1k can always be corrected so that the torque fluctuation becomes smaller. However, if ik becomes less than 0 during the correction in step 130, that is, if the torque is still insufficient even after the load current is set to 0 and the absorption torque is set to 0, the determination is made in step 131, and a new Step 1 to generate torque as an electric motor
Move to 40.

Similarly, if it is determined in step 120 that the motor was operating before cycle Ⅰ, the control moves to step 140 and sets the armature current command i, i+t=ih-kM・ak (kM is positive constant)
・Correct in the form of (2). According to equation (2), when the torque generated by the engine is insufficient, that is, when a-<0, ik is increased to increase the generated torque, and when there is a surplus of torque, In other words, when ak>0, lb is decreased to reduce the generated torque, so
Armature current command i is always set so that torque fluctuation is small.
b can be corrected. However, if ih becomes less than 0 during the correction in step 140, that is, if the ftL1 child current is set to 0 and the generated torque is set to 0, there is still a surplus of torque.

The determination is made in step 141, and the process moves to step 130 to absorb torque as a new generator.

The load current command or armature current command ik newly obtained through the above process is outputted to the torque control section 7 and the pulse distributor 5f in step 160. What is important here is the calculation speed of the microcomputer 6. If the calculation speed is sufficiently fast compared to the rotational speed of the crankshaft and the processing from steps 110 to 160 can be completed without a large time delay, there is no problem.If the calculation speed is slow and the processing takes a long time. If this becomes a problem for control, the torque fluctuations generated by the engine will occur as shown in Figure 9.

Noting that it is a periodic pulsation with one combustion cycle as one period as shown in Fig. 10, the newly obtained command value 'A
If h is output when the second rotational pulse is detected after one combustion cycle, it is possible to achieve control effects that are almost the same as when the calculation speed is fast and without time delay.

After outputting the command value 1k as described above, step 17
After updating the pulse count value k at 0, step 1
10 to prepare for the next rotation pulse detection.

Figure 11 shows rotational acceleration data when performing control.
This shows a method of stocking data up to several cycles before the current one and determining the control amount using the averaged data. Now, if we take a weighted moving average over the past n cycles for the rotational acceleration data 81H at the crankshaft rotation angle corresponding to the k-th rotation pulse, we get -〇ak'' ΣAI-ak amount...
(3) It is expressed as i=1. Such averaging processing is performed, for example, in the 11th
This can be done by using a linear recursive digital filter as shown in the figure.

However, A□ is a weighting coefficient applied to data from i-1 cycle before, and A t = Ax= ・= −A n=
- (4), equation (3) becomes a simple equation for calculating the arithmetic mean. Since the torque fluctuations generated by the engine (i.e., the rotational acceleration fluctuations of the crankshaft) are periodic, by using this type of averaging processing, it is possible to prevent the control from becoming unstable due to fluctuations that occur accidentally. Since the torque fluctuation can be minimized and the dominant component of torque fluctuation can be reliably controlled, reliability can be further increased.

FIG. 12 is a diagram showing a second embodiment of the present invention. This is because, in the first embodiment shown in FIG. 4, the absorption torque when the motor generator 5 operates as a generator was controlled by load current control, whereas in the second embodiment, the rotor coil ( This is done by controlling the field current flowing through the field coil) 5b. In other words, increasing the field current increases the strength of the field generated by the rotor coil.

Accordingly, the torque required to drive the motor generator 5, that is, the absorption torque of the motor generator 5 increases. Therefore, from the rotational acceleration fluctuation of the crankshaft obtained by the crank angle sensor 3, the microcomputer 6 calculates the required absorption torque magnitude and the magnitude of the field current to realize it as a command value, and outputs the command value. The amount of field current flowing through the rotor coil 5b may be controlled in synchronization with the rotor coil 5b. As shown in FIG. 12, the means for this purpose is to detect the magnitude of the field current flowing through the rotor coil 5b, and set a field current regulator (ACR) 18 so that this becomes equal to the command value of the microcomputer 6. , and the transistor switch 20 is set to 0 through the driver 19.
It is possible to do N10FF. When the transistor switch 20 is in the ON state, the field current flows from the collector to the emitter, so a current also flows to the rotor coil 5b.
Conversely, no current flows when it is in the OFF state.

By changing the duty ratio of 0N10FF at this time, a desired field current can be caused to flow.

The 13th is a diagram showing engine generated torque, generator absorption torque, and torque generated during torque control when torque control is performed using a flywheel generator as an electric drive device.

In the figure, the broken line indicates the surplus portion of the torque fluctuation (section A).

The solid line shows the case where control is performed so that only C) is absorbed by the generator, and the solid line shows the case where the absorption torque is controlled so that the torque fluctuation becomes O. How much torque fluctuation needs to be reduced? The magnitude of the absorption torque can be determined by:

In addition, Fig. 14 is a diagram showing engine generated torque, motor generated torque, and torque generated during torque control when torque control is performed using a flywheel motor as a driving device. The broken line shows the case where control is performed so that only the shortfall (section B) of the torque fluctuation is compensated for by the torque generated by the motor, and the solid line shows the case where the torque fluctuation is O
This shows the case where the generated torque is controlled so that

【Effect of the invention〕

As described above, according to the present invention, torque fluctuations generated by the internal combustion engine are detected, and the torque absorbed or generated by the electric drive device provided in the main power transmission system is controlled so as to reduce the torque fluctuations. Therefore, it is possible to reduce the fluctuation component of the torque transmitted to the main power transmission system and the auxiliary drive system, as well as the vibration of the engine and vehicle due to the torque reaction force.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a torque control circuit when a flywheel motor generator is used as an electric drive device as an embodiment of the present invention, and Figs. 2 and 3 show rotational pulses output from a crankshaft sensor and FIG. 4 is a circuit diagram of the torque control device according to the first embodiment of the present invention. FIG. 5 is a diagram showing an example of the torque waveform during torque control. FIG. 7 is a circuit diagram of the torque control section of the first embodiment and an example of a chopper signal used therein, FIG. 8 is a control flow diagram of the torque control device, and FIGS. 9 and 10 are diagrams showing an example of the chopper signal used therein. A diagram showing an example of a torque waveform generated by an internal combustion engine, FIG. 11 is a circuit diagram of a digital filter when using averaged data,
FIG. 12 is a circuit diagram of a second embodiment of the present invention, and FIGS. 13 and 14 show torque waveforms when torque control is performed using a flywheel generator and a flywheel motor as electric drive devices, respectively. It is a figure showing m pieces. 5... Flywheel motor generator as an example of an electric drive device, 6... Microcomputer, 7.
...Torque control section.

Claims (1)

[Scope of Claims] 1. In an internal combustion engine, the main power transmission system is equipped with a voltage drive device capable of operating as a generator, operating as an electric motor, or operating as a generator and an electric motor. a detection means for detecting a torque fluctuation component for each rotation angle of a main shaft of an internal combustion engine, and a control means for controlling torque absorbed or generated by the electric drive device based on the detected torque fluctuation component, Torque control for an internal combustion engine, characterized in that the control means changes the magnitude of the torque absorbed or generated by the drive device for each rotation angle of the main shaft of the internal combustion engine so that torque fluctuations generated by the engine are reduced. Device. 2. The control means uses a torque fluctuation detected at each rotation angle one combustion cycle before as a torque fluctuation component at each rotation angle of the main shaft of the internal combustion engine, as set forth in claim 1. Torque control device for internal combustion engines. 3. The torque control device for an internal combustion engine according to claim 1, wherein the detection means detects rotational acceleration fluctuations of a main shaft of the internal combustion engine. 4. A flywheel generator is provided as the electric drive device, and when the torque fluctuations generated by the engine increase, the amount of power generated by the generator is increased to increase the torque absorbed by the generator, and conversely, the engine generates more torque. 2. The torque control device for an internal combustion engine according to claim 1, wherein when the torque fluctuation decreases, the absorbed torque is reduced by reducing the amount of generated electricity. 5. A flywheel motor is provided as the electric drive device, and when the torque fluctuation generated by the engine decreases, the torque generated by the motor is increased by increasing the voltage input to the motor, and conversely, the torque generated by the engine is increased. 2. The torque control device for an internal combustion engine according to claim 1, wherein the generated torque is reduced by reducing the electrical input when the torque fluctuation increases. 6. A flywheel motor generator is provided as the electric drive device, and when the torque generated by the engine is larger than the average torque, the motor generator is operated as a generator to absorb the excess torque, and conversely, the engine generates the excess torque. 2. The torque control device for an internal combustion engine according to claim 1, wherein when the torque is smaller than the average torque, the motor generator is operated as an electric motor to generate the insufficient torque.