JPH048626B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention was applied for a patent in the United States on April 8, 1983 (currently withdrawn), and is entitled "Ignition timing optimization device for diesel or spark ignition engine." Continuing in part from patent application no. 483188 entitled .

The present invention relates to an adaptive control device for improving the performance of a motor such as an internal combustion engine, and more specifically,
This invention relates to a closed-loop control system that is stable over a wide range of engine speeds.

[Conventional technology]

Patent No. 4,026,251 to Schweitzer et al. describes a closed-loop digital electronic control system for an engine, in which:
perturbations are applied to engine control parameters near given set values, while simultaneously monitoring engine performance.
It is determined which side of the given set value the control parameters should be moved to improve performance. If changing the settings improves performance, control signals generated by the electronic circuit are used to change the control settings in a direction that improves performance. However, if performance deteriorates as a result of small changes, the engine set point is changed in the opposite direction.

In devices based on the above-mentioned Schweitzer et al. patents, engine performance monitoring is accomplished by integrating "celsig" pulses during predetermined perturbation periods. The "celsig" pulses are generated from the engine's rotating shaft, flywheel or generator, and their frequency is proportional to the engine speed. The logic circuit of the control device uses a counter, which is divided into four sections. A counter counts the number of "celsig" pulses in each quadrant of the perturbation period. The counter increases the count value in the first quadrant;
It is used to decrease in the next two quadrants and again to increase in the last quadrant. The count remaining in the UP/DOWN counter at the end of each counting cycle is used to determine in which direction the engine control parameter settings are to be changed. These corrections continue until the perturbations applied to the engine control parameters no longer cause significant fluctuations in engine speed, indicating that the maximum braking torque (MBT) set point has been reached.

“celsig” is required for this device to work properly.
It can be seen that it is necessary that the number of pulses is sufficiently large and that a large number of engine periods are included in the perturbation period, that is, that the rotational frequency of the engine is sufficiently larger than the perturbation frequency. If the engine frequency is not sufficiently greater than the perturbation frequency, control will be lost.

The reason for this loss of control is thought to be that in the conventional device, the perturbation pulse is asynchronous to the engine cycle. That is, in the above-mentioned device of the Schweitzer et al. patent, the perturbation frequency is fixed and precisely determined by an electronic oscillator. The switch from "lead" to "lag" and vice versa therefore takes place at the beginning or midpoint of the perturbation period, and is independent of the rotation of the engine shaft and the ignition pulse. As a result, as will be discussed in more detail below, there are inherent variations in engine speed, and cylinder-to-cylinder ignition timing is sometimes accelerated and sometimes decelerated by perturbations to the engine control parameter settings.

[Summary of the invention]

In the present invention, the perturbation frequency is not fixed, but is synchronized with the normal operating cycle of the engine.
That is, each perturbation cycle begins at a fixed position in the axis angle, and each phase (lead and lag) of the perturbation cycle has the same number of firing pulses. Therefore, the cylinder ignition timing of the engine does not continuously shift in response to perturbations in the engine control parameters. Computer simulation results show that this synchronous perturbation method significantly reduces errors in the entire rotational speed range compared to conventional techniques, and is particularly effective when the engine rotational frequency is similar to or slightly smaller than the perturbation frequency. It turned out to be.

In an embodiment of the invention, an engine shaft rotation detector is provided, which includes a detectable mark on the flywheel to indicate when a particular cylinder of the engine has reached top dead center. There is. A fixed side detector is also included which generates an impulse each time a landmark passes the detector. A further device is provided to measure the time required for the shaft to rotate a predetermined number of times. 1
One way is to use a very high frequency, e.g. 10MHz.
Pulse generators are used. These pulses are integrated by a counter, and this counter is started/stopped in synchronization with the rotation detection signal issued by the fixed-side landmark detector. By dividing the perturbation period into four and integrating the high frequency clock pulses by four counters, the value stored at the end of the perturbation period represents the average rotational speed in these four divisions. A logic circuit is provided which compares the average speed in the first and fourth sections with the average speed in the second and third sections and outputs a control signal depending on the sign of the difference; This signal is input to a converter connected to the engine control parameter settings and
The set value is changed by a predetermined amount in a direction that improves the performance of the device.

Proportional control is also possible, in which case the amount of correction is related not only to the polarity of the error signal but also to the magnitude of the error signal. The algorithm of the invention can be implemented using discrete logic elements as suggested above, or using a suitable microprocessor.

The Schweitzer et al. patent, No. 4,130,863, states that under certain circumstances it may be desirable to adjust the adaptive control system to operate the engine away from the MBT condition. This operating method that deviates from the optimal state is called the "bias method." The bias method is equally applicable to the present invention regardless of whether discrete logic elements or microprocessors are used.

As already indicated, in a control system constructed in accordance with the invention, each phase of the perturbation period, leading and lagging, includes an equal number of engine speeds or ignition pulses and is equal to the start of each perturbation pivot. The end point is synchronized with the engine cycle or pulse. It is known that controllability can be improved if the engine speed or the number of ignition pulses included in the perturbation phase can be selected as a function of the engine speed. Therefore, for example, when the engine speed is from 0 rpm to 2000 rpm, each perturbation period is two rotations of the shaft (one engine period of a 4-stroke engine), whereas when the engine speed is from 2000 rpm to 4000 rpm, each perturbation period is , each perturbation period consists of four rotations of the axis. This allows more clock pulses to be integrated during each perturbation period, improving the accuracy of the error signal. Furthermore, it provides relatively sufficient time for the engine to respond to changes in ignition timing, which also facilitates the measurement of error signals. Of course, in higher rotation ranges it is also possible to use other values for the number of rotations per perturbation period.

When applying the method and apparatus of the present invention to a diesel engine, adjustment work is required to compensate for differences in injection timing between fuel injection devices. The electrically driven diesel fuel injectors and injection valves are linked to each other with mechanical or electrical delays, which can be changed individually. Therefore,
When precise ignition timing control is required for fuel injection systems, a suitable device is needed to adjust for differences between individual injection systems.

With the method and device according to the invention, a global optimization of the ignition timing or injection timing of a diesel or spark ignition engine is possible. However, if there is a large time difference between individual fuel injectors,
If these differences are not taken into consideration, large differences in ignition timing between cylinders will remain. As a result, the injection amount increases and fuel efficiency deteriorates. The device and method according to the invention solves this problem in the following way: the relative delay between the injectors is determined by optimizing the ignition timing of the individual cylinders. By knowing these individual ignition timing differences, a suitable control circuit can be devised to compensate for changes in the performance characteristics of the injector.

[Purpose of the invention]

A first object of the invention is to provide an adaptive control device for use in a motor vehicle.

Another object of the invention is that the engine control parameters are varied back and forth around a given set value;
It is an object of the present invention to provide an adaptive control device of the type that generates a control signal depending on whether the slight fluctuation improves performance or not.

Yet another object of the invention, in connection with the above-mentioned objects, is to provide an adaptive control device in which variations in engine control parameter settings are synchronized with a period specific to the engine being controlled. .

Yet another object of the present invention is to provide a "perturbation" type adaptive control device in which the perturbation frequency is variable.

Yet another object of the present invention is to provide a "perturbation" type adaptive control system in which each phase of the perturbation period has the same number of engine periods and is synchronized with the operating period of the engine.

Yet another object of the present invention is to provide an adaptive control system in which the number of engine periods included in a perturbation period varies depending on the speed of the engine.

Still another object of the present invention is to provide a method and apparatus for optimizing the injection timing of each cylinder by determining the operational deviation between a plurality of injection valves used in a multi-cylinder diesel engine.

These objects and advantages of the present invention will be apparent to those skilled in the art from reading the following detailed description of the submitted embodiments, particularly with reference to the accompanying drawings. Become.

〔Example〕

FIG. 1 is a simplified block diagram of an adaptive control system according to the present invention. An illustrative internal combustion engine 10 is shown having an output shaft 12 coupled to a load 14 . A flywheel 16 is fixed to the shaft. A detection mark such as a permanent magnet 18 is arranged around the flywheel 16, and the fixed side detector 2
When it passes by 0 while rotating, it generates a voltage signal. Such a pulse signal is sent to flywheel 1.
Generated every 6 revolutions.

Also connected to the engine 10 is a control device 22, which can be of various shapes depending on the characteristics of the machine to be controlled. For example, in a gasoline engine, the controller 22 is a distributor timing device, while in a diesel engine, the controller 22 is the engine's fuel injection control device.

The block 24 labeled "perturbation" is an electronic or electromechanical device that is connected to the controller 2.
2 to add a predetermined variation to the machine's normal control setpoint. U.S. Patent No. 4,026,251, issued to Schweitzer et al.
No. 3,142,967, No. 413,863 and Malcolm Patent No. 4,306,284).
Although the perturbation period was fixed and had no particular relation to individual ignition timings within the engine, in the present invention, a digital logic element 26 controlled by rotation detectors 18-20 adjusts the control settings 22 to the engine 10. It changes back and forth in synchronization with the individual ignition pulses within. The time required for engine shaft 12 to rotate a predetermined number of times during each perturbation is determined by using a high frequency clock pulse signal output from clock source 28 with a suitable counter controlled by rotation detectors 18-20. It is measured by counting. Once one period of perturbation is completed, the expected average speed in the second and third quadrants of the perturbation period and the actual speed in these two quadrants until the ignition timing is not perturbed, i.e., late condition. A comparison is made with speed. A simple estimate of this speed is obtained by averaging the speeds of the first and fourth quadrants. This predicted value is accurate enough when the engine is stable or slowly changing. During a rapid change in velocity, the first
A more accurate prediction can be obtained using the velocity values of the second and fourth quadrants. In response to the result of the comparison, logic device 26 outputs an error signal on output line 30 to adjust control settings 22 through servomechanism 32 . Device 32 can be configured to be all-electronic or electromechanical.

If the optimization algorithm according to the present invention is applied to the injection system of each cylinder independently of a diesel engine, rather than to all cylinders together, the engine will operate at a nearly constant speed with constant fuel consumption, which is preferable. The vehicle enters a high-speed idling state. next,
The timing of the individual injectors is a control setting 22 that is perturbed synchronously with the rotation of the crankshaft. The timing of the remaining injectors is fixed. Then, when a perturbation period is completed, the expected average output shaft velocity in the second and third quadrants of the perturbation period if no perturbation was applied to the injector, and the actual output shaft speed in these two quadrants. The speed is compared. Logic device 26 again outputs an error signal which, through servomechanism 32, makes adjustments to the injector.

For reference, FIG. 2 shows the engine speed (curve A) and cylinder pressure (curve B) over two revolutions (crankshaft angle of 720 degrees) of a six-cylinder engine. The graph of FIG. 2 therefore shows one cycle of the engine including the firing conditions of all six cylinders. As the cylinder pressure (curve B) increases, the shaft speed (curve A) decreases. When igniting, the piston moves downward, which lowers the internal pressure and increases the shaft speed. The next fired piston begins to rise, compressing the air/fuel mixture in the cylinder, causing the cylinder pressure to rise again and the shaft speed to decay. Although the speed curve (curve A) has a substantially sinusoidal waveform, there are variations in speed due to differences in the ignition state of each cylinder, and this is reflected as a difference in the individual maximum values of the speed curve.

Due to the normal fluctuations in engine shaft speed, asynchronously applying perturbation signals to the engine's control settings can sometimes increase speed increases or conversely reduce speed increases. Similarly, delays in control settings may inhibit speed increases or encourage speed decreases. In fact, it is known from experience that control devices manufactured based on the above-mentioned Schweitzer patents and Malcolm's patents sometimes have a reduced tracking ability or that the error signal sent to the servo device fluctuates in an uncontrollable manner. ing.

Figures 7a and 7b are crank angles (CAD)
This figure shows the fluctuation of the ignition timing error and the fluctuation of the ignition timing itself together with the rotational speed of the engine, and uses a prior art adaptive control device. What should be noted is that the ignition timing and the ignition timing error fluctuate greatly in the low rotation range, with large swings around the zero error position. Although the ignition timing error is fairly stable in the high rotation range, fluctuations other than the effects of changing the control parameters by perturbation can still be seen. Furthermore, during acceleration and deceleration, transient fluctuations occur in the ignition timing and ignition timing error. FIG. 7a shows the case where the perturbation period is 4 Hz. FIG. 7b shows a waveform when the perturbation period is set to 2 Hz using a control device using the prior art. In this case as well, it can be seen that the ignition timing error fluctuates greatly in the low rotation range.

According to the present invention, the engine control parameters are not perturbed at a fixed period, but the perturbation period is synchronized with the normal engine rotation period. Therefore, the total number of ignition pulses that occur during each half of the perturbation period (curve B in Figure 2) and the beginning and end of the perturbation period must occur synchronously with the ignition time of a particular cylinder in the engine. become.

In FIG. 3, reference numeral 34 indicates a perturbation waveform. Here we are considering a 4-cycle engine,
The output shaft rotates twice during one cycle of the engine. The perturbation period consists of two phases: a leading phase and a lagging phase.

Waveforms 36 and 38 in FIG. 3 show the shaft velocity in leading and lagging phases during perturbation period 34.
If the engine setting lags behind MBT (maximum braking torque), the shaft speed increases during the lead phase and decreases during the lag phase. This condition is illustrated by waveform 36 in FIG. On the other hand, if the engine control settings are advanced relative to the MBT, if the settings are further advanced in the first half of the perturbation period, the speed will decrease, and if the settings are delayed in the next phase, the speed will increase. This condition is illustrated by waveform 38 in FIG.

As will be explained in more detail later, when constructing a control device according to the invention, it is preferable to divide the perturbation period into a plurality of periods. Specifically, as shown in FIG. 3, the perturbation period is divided into four parts, each of which is divided in advance by the rotational speed of the shaft. The logic unit 26 calculates the time required for each rotation Δt ₁ , Δ
Equipped with measuring equipment such as _t2 .

The simplest way to implement the control function is to determine in logic unit 26 whether the rotational speed at the midpoint of the perturbation period is greater than the rotational speed at the beginning or end of the perturbation period. More specifically, the sum of the times required for shaft rotation in the second and third quadrants of the perturbation period is subtracted from the sum of the times required for shaft rotation in the first and fourth quadrants. do. If the result is positive, it is known that performance will improve if the engine control settings are advanced. However, if the difference is negative, it is known that the parameter setting must be delayed from the current value because adding a perturbation will degrade performance. If the concept of bias is not included, the calculation formula for this error can be expressed mathematically as follows: (1) E = (△t ₁ + △t ₄ ) − (△t ₂ + △t ₃ ) where △ t ₁ , Δt ₂ . . . Δt ₄ are average rotation times in each quadrant of the perturbation period, as shown in FIG.

In the aforementioned Schweitzer et al. patent and the Malcolm patent, shaft velocity was measured by counting the number of so-called "celsig" pulses occurring within a predetermined interval of the perturbation period.
In the present invention, since the perturbation period is synchronized with the rotating shaft of the engine, the average speed is determined by counting the number of high-frequency clock pulses input to a digital counter while the output shaft rotates a predetermined number of times. . Replacing the prior art "celsig" pulse generator with an electronic high frequency oscillator or clock generator reduces device cost and improves performance. FIG. 4 shows how an adaptive control device according to the invention can be constructed using discrete logic elements. As shown, the engine shaft 12 drives a flywheel 16 on the periphery of which a magnetic element 18 is associated with a detection coil 20. An electrical impulse signal is therefore generated on conductor 40 each time the flywheel rotates. Here, we have obtained satisfactory results using a combination of magnets and magnetic detectors, but those skilled in the art will appreciate that other methods can also be used to detect fixed points on the rotating flywheel. It will be appreciated that an electrical signal can be generated when passing a location. Accordingly, the invention is not to be construed as limited to magnetic sensing methods.

The signal appearing on line 40 is connected to the counting input terminal of a four-stage counter 42. The outputs t ₁ to t ₄ of each stage are connected to first inputs of gate circuits 44, 46, 48 and 50, respectively. The second inputs of these gates are connected via conductors 52 to a high frequency oscillator 54 . The output stages t ₁ and t ₃ are also set/reset type flip-flops triggered by a rising signal.
It is connected to flip 56, and this flip
The output of the flip is passed through a converter (not shown) to
It is connected to the control setting device 22 of the engine.

Each matching circuit 44-50 is connected to a multi-stage binary counter 58, 60, 62 and 64. The outputs from counters 58 and 64 are both input to a first full adder circuit 66, and the outputs from counters 60 and 62 are input to a second adder 68. The outputs from adders 66 and 68 are input to subtracter 70, and a positive or negative signal appears on output line 72 depending on the result of the operation. This signal is input to a suitable electronic device which makes stepwise adjustments to the engine control parameter settings, the direction of the adjustment being determined by the polarity of the output signal on output line 72.

4 with reference to Figures 2, 3 and 4.
An internal combustion engine control device configured by the method shown in the figure will be explained. The detector 20 is mounted on a fixed frame and operates in conjunction with the flywheel 16 or other elements on the engine shaft that rotate in synchronization with the engine, and sends electrical pulses to the output line 4 each time the flywheel 16 rotates.
0 in synchronization with the engine's ignition cycle. The initial state of counter 42 is zero and is advanced to the _t1 state by the rising pulse appearing on line 40. In this state, the flip-flop 56
is set such that the perturbation device advances the engine control settings from the current value. At the same time counter 42
The t ₁ output of makes the gate 44 ready for reading,
The high frequency clock pulses from oscillator 54 pass through a gate and are integrated by counter 58. When the flywheel 16 completes one revolution, an impulse signal appears on the output line 40 again to update the counter 42. In other words, the counter 42 is in the _t2 state.
In this state, gate 44 is closed and the clock pulse input to counter 58 is cut off.
Meanwhile, gate 46 is enabled for reading and the clock pulses from oscillator 54 pass through the gate and are integrated in counter 60. This state continues until the flywheel completes one rotation again and the counter 42 reaches the _t3 state. Two functions are performed that result in counter 42 being in the _t3 state. First, the output signal of the counter 42 is input to the reset terminal of the flip-flop 56, which puts the flip-flop in a "lag" state, and the output ultimately changes the engine control parameter setting in a direction that lags behind the current set value. This is a function to move the The second allows gate 48 to be read while gates 44 and 46 are closed and oscillator 54
This function causes the counter 62 to integrate the clock pulses from the clock pulses. Next, when one rotation of the flywheel 16 is completed, the counter 42 switches to the _t4 state, all gates except the gate 50 are closed, and the counter 64 receives the clock pulse from the oscillator 54 when the output shaft of the engine is in the t4 state. Receive while rotating.

In the configuration shown in FIG. 4, the flywheel 1
The values stored in the counters 58 to 64 at the time when 6 has completed four rotations are inversely proportional to the average rotational speed of the output shaft within each of the four sections shown in FIG. Although not shown in detail in the logic block diagram of FIG. 4, a temporary memory is provided for storing count values for subsequent arithmetic operations. The reason for this is that the counters 58 to 64 are all cleared when the next complete revolution of the flywheel is completed. Since a temporary memory is provided, counters 58, 60 and 62 may be cleared as soon as the _t4 period of counter 42 begins and the next
At the beginning of the _t2 period, a clear pulse is sent to counter 64 through line 74 to clear its contents and wait to receive a pulse from oscillator 54 on the next period.

The values accumulated in counters 58 to 64 during the first perturbation period are stored in adders 66 and 6 during subsequent perturbation periods.
8 is added. The contents of counters 60 and 62 corresponding to the average rotation time at the midpoint of the perturbation period in the error calculation formula shown above are added by an adder 68 to give the average rotation time at the beginning and end of the perturbation period. The contents of corresponding counters 58 and 64 are added in adder 66. In the subtracter 70, the adders 66 and 6
8 is calculated to determine whether the average time at the midpoint of the perturbation period is larger or smaller than the average time at both ends of the perturbation period. This can be determined by the polarity of the signal appearing at the output 72 of the subtracter 70.

The configuration of the individual logic elements shown in FIG. 4 is only one configuration example for solving the speed equation shown above, and an engineer familiar with this technical field will understand that there are other configurations that can be used to obtain the same result. It is understood that the logic circuit of can be devised. Although this embodiment does not particularly process the bias signal for the error signal, this can also be realized using a separate logic circuit. However, the device according to the invention essentially differs from devices according to the prior art in that the perturbation period is synchronized with the rotation of the engine shaft and the average rotation time of the shaft is generated by a transducer mounted on the output shaft of the engine. It is calculated not by "celsig" but by integrating the output signals from the stabilizing oscillator (oscillator 54). As a result, speed can be measured with greater precision than the prior art disclosed in the Schubeitzer et al. and Malcolm patents discussed above.

It will be appreciated by those skilled in the art that the logic element 26 shown in FIG. 1 can be constructed more flexibly using a microprocessor than the discrete digital elements shown in FIG. be understood. Next, the case where the present invention is constructed using a microprocessor will be considered.

Figure 5 shows a Motorola microcomputer.
FIG. 2 is a block diagram of the internal configuration of MC6801. This is a single-chip N-MOS device in which the arithmetic processing unit 80, RAM 82, ROM 84, internal timer 86, communication interface 88, and input/output sections 90, 92, 94, and 94 are arranged on the same silicon chip. has been done. The MC6801 microcomputer can operate in one of three basic operating modes.
It can operate in two modes. More specifically, this IC can function independently as a single element, and in this case, the number of input/output lines that can be used is limited to the number of elements on the chip. It can also be operated in a so-called "extended, non-multiplexed mode" in which read and write operations can be performed to external storage or other devices via a separate data bus. Finally, there is the so-called "extended, multiplex mode" in which the address and data buses are time-divided and a 64K byte address space can be generated, but it is necessary to demodulate the signals on the bus. The invention allows the device to be used in a first or single chip mode since it does not require much storage capacity.

The timer function of the MC6801 can be effectively utilized when a microprocessor is applied as a control device based on the present invention. The timer 86 is a 16-bit counter that is updated by the clock from the crystal oscillator inside the MPU 80. The count value is MPU
The overflow flag is set each time the 16-bit counter becomes all 1. This timer therefore measures the time between two events, e.g. pulses from successive flywheel transducers,
It can be used to measure the time between gaps.

Details regarding the architecture, features, programs, and application examples of the Motorola MC6801 microcomputer can be found in the 1980 edition of "MC6801 8-Bit Single Chip Microcomputer Instruction Manual" published by Motorola. Those who wish to know the details of the types, calculation times, addressing formats, and programming methods should refer to the above-mentioned manual.

FIG. 6a is a flowchart of a program input to the microprocessor for calculating the error signal in synchronization with the rotation of the engine shaft. The computer is programmed to perform error calculations using the following error formula: E = △t _CD - △t _CD where △t _CD is the ignition timing for two engines in the four quarters of the perturbation period. △t CD is the estimated time when no perturbation (advancement) is applied, and △t _CD is the actual measured time when perturbation is applied to the two quadrants,
That is, △t ₂ + △t ₃ . △ in the simplest case
t _CD is △t ₁ + △t ₂ . This is sufficient if the engine speed is constant or slowly changing. However, if the velocity change is sudden, a more accurate estimate of Δt _CD can be obtained using information from the previous perturbation period. For example, if the relationship between time and engine rotational speed can be approximated by a fourth-order polynomial, then △
Using t _-4 , △t _-1 , △t ₁ and △t ₄ (see Figure 3), a more accurate estimate of △t _CD can be made, which is given by: △t _CD = A△t _-4 +B△t _-1 +C△t ₁ +D△t ₄ where A, B, C and D are constants obtained by approximation. Adding a bias term to the error equation
It is also possible to operate in a state slightly advanced or delayed from MBT (maximum braking torque) operation. Therefore, the final error formula is E=A ₄ △t _-4 +B ₄ △t _-1 +C ₄ △t ₁ +D ₄ △t ₄ −△t ₂ −△t ₃
+bias, and this bias value can be obtained from the table. (△t ₁ +△t ₂ +△t ₃ +△t ₄ ) A bias value proportional to ² causes a lead or lag of an approximately constant angle from the MBT. The microprocessor executes the instructions written in the main processing program shown in Figure 6a until the rotation detector detects the passage of the position landmark.
When the detector detects the passage of a position landmark, it generates an interrupt signal, which signal is shown in FIG. It is input to input terminal 1 of the microprocessor. In response to this signal, the MPU 80 executes a jump instruction and jumps to the address where the interrupt processing instruction is shown in the flowcharts of FIGS. 6b and 6c.
As soon as the execution of the interrupt handling instruction is complete, the instruction automatically returns to the main handling program.

First, the main processing program shown in FIG. 6a will be explained. When the power of the microprocessor is turned on, in preparation for execution of the adaptive control algorithm according to the present invention, the so-called quadrant count value, error value, and period index are is initialized. The main processing program begins by setting the quadrant index to zero. The quadrant index value is updated every time an interrupt process is executed. Then the error value is also set to zero, and the quadrant count value of the previous cycle is replaced by the count value of the current cycle, e.g., the first quadrant of the now ended cycle after the value of △t _-4 of the previous cycle. The value of the interval △t is equal to ₁ . The remaining quadrant counts are updated in a similar manner. Expressed numerically, this data update is shown as follows: New cycle value Value of the now completed cycle △t _-4 = △t ₁ △t _-3 = △t ₂ △t _-2 = △t ₃ and △t _-1 = △t ₄ .

Here, Δti is the time required for the shaft to rotate a predetermined number of times, and (i) is the number of the quadrant that has elapsed since the start of a new cycle, as shown in FIG.

Following this data replacement operation, the next operation is to calculate a periodicity index and, if this value differs from the previous value, to set a new periodicity index flag. The period index is calculated by the following formula: n=1 if △t _-1 > T ₁ n=2 if T ₁ >△t _-1 > T ₂ n=4 if △t _-1 < T ₂ It is.

Here, T ₁ and T ₂ are reciprocals of the rotational speed at the switching point at which the period index n is updated. It is optional to use the period index or update this value, and this is to reduce the frequency of the counter used, and it is also possible to use a constant as the period index. The next step is to determine whether or not to use the approximation method for error counting. If the period index is the same as the previous period, the period index flag is set to zero and Δt _-4 and Δt _-1 are used to start the error calculation. The next process in the main program is the weighted error count A from the previous cycle.
This is to add △t _-4 +B△T _-1 to the cumulative error. If the period index flag is set to 1, the last process is bypassed.

The main program then enters a wait state until the quadrant index is equal to three. When said index is equal to 3, a data entry task is processed to input the digital values representing the load and the digital values from the other detectors. For example, in a spark ignition engine, a knock detector may be used to reduce the bias value to reduce the amount of knock to an acceptable level. This process is performed subsequent to calculation of cycle time. Calculation of this cycle time can be easily obtained using the following formula: Δt=2·(Δt ₂ +Δt ₃ /n) where n is a cycle index. The total cycle time is indicated by Δt.

Once the period time is calculated, the bias factor is then calculated. This task is conveniently performed using a table stored in ROM memory 84 (shown in FIG. 5). i.e. engine load value or cycle time,
Similarly, a value is obtained from a table based on other coefficients obtained from a suitable detector and multiplied by the square of the period time to obtain a bias value, which is added to the error if bias correction is required.

Next, the system waits until the quadrant index reaches 4, and when the index reaches 4, a correction value is calculated. The correction value may be a value proportional to the error, or it may be a signal whose magnitude is constant and only the correction direction differs; in that case, if the error exceeds a positive limit value, correction is performed in the positive direction; If the limit value of is exceeded, the calculated value shall be modified in the negative direction. The microprocessor then outputs a control signal that updates the engine parameter settings by adding the calculated correction factors, and the process returns to the beginning with the quadrant index and error set to zero.
If the ignition timing is advanced, the perturbation signal and the correction value are added to the previous value of the parameter setting.

Now that we have finished explaining the main processing program, we will now explain interrupt processing. This point will be explained with reference to FIGS. 6b and 6c. As mentioned earlier, the interrupt processing is performed by the detector 18-20 (the first
It is executed in response to an interrupt signal output from (Figure). The first task in the interrupt handling program is to update the periodicity coefficient. Next, it is determined whether the period count is equal to the period index value. If they do not match, the interrupt program returns to the main processing program. On the other hand, when the period count is equal to the period index value,
The interrupt handling program reads time data from the computer's interval counter and simultaneously initializes the counter to prepare it for subsequent reception of high frequency clock pulses. Next, the quadrant count value is updated. After updating the quadrant count value, a determination is made whether the new value is equal to 2 or not. If equal, this means that half of the perturbation period has been completed, and the parameter settings are delayed by the processing of normal perturbation periods. In practice, the ignition timing is retarded by subtracting the amount of perturbation from the current ignition timing as determined by the machine's parameter control settings.

After switching the perturbation signal from leading to lagging at the intermediate point, two types of operations can be selected for updating the error value. In particular, if the current period index is new or different from the previous value, the operation proceeds along the left branch of the flowchart. First, it is determined whether the quadrant count is equal to 1 or not. If they are equal, the time count value is added to the cumulative error value, and the time count value at this time is stored as _Δt1 . If the quadrant count is not equal to 1, it is determined whether this value is equal to 2 or not. If it is equal to 2, subtract the time count value from the error and store it as Δt ₂ . Quadrant counting is 1 or 2
If it is not equal to , it is determined whether or not it is equal to 3, and if it is equal, the time count value is subtracted from the error and at the same time, the time count value is stored as Δt ₃ . Finally, if the quadrant count is equal to 4, then
Add the time count value to the integration error and calculate the time count value △t ₄
be memorized as .

The above is a case where the period index is a new value. If, on the other hand, the period index is equal to the previous period index value, the processing program follows the right branch of the flowchart and the error calculation method is slightly different.
Specifically, if the quadrant count is determined to be equal to 1, the weighted time count value is added to the cumulative error. This weighted count value is the current time count value△
It is t ₁ multiplied by a constant count (C).

If the quarter count value is equal to 2, the error value is updated by subtracting the current time count value from the accumulated error, and the clock value is stored as △t _2. If the quarter count value is equal to 3, The error value is updated by subtracting the current time count value from the accumulated error, and the time count value is stored as Δt ₃ .

Finally, if the quadrant count value is equal to 4, the weighted time form value is added to the cumulative error and this weighted count value is D・△t ₄ , and the time count value is memorized and used later in the program. used in Regardless of whether the interrupt processing program has proceeded through the flowchart on the left or the flowchart on the right, once the determination of whether the quadrant count value is equal to 4 and the subsequent arithmetic processing have been completed, the process returns to the main program.

The flowchart shown in FIG. 6 merely shows an example of a program for implementing the present invention using a general-purpose microprocessor. A person familiar with this technical field will be able to easily translate this flow into assembler language and compile it into machine language. Therefore, it is considered unnecessary to present a detailed command list.

Figures 8a to 8f show the results of a computer simulation when the control device according to the present invention is applied to fuel injection timing control of a diesel engine.
The content of the diagram shows the engine speed at the bottom and the injection timing error and injection timing at each point in time. Comparing these waveforms with the waveforms shown in FIG. 7, which are the results of the prior art, it can be seen that fluctuations in the low rotation range are almost eliminated. Similarly, as a result of adopting the synchronous perturbation method according to the present invention, fluctuations in both injection timing and injection timing error are reduced. In both devices, transient fluctuations occur during rapid changes in speed, but Figures 8a to 8
Comparing the waveforms up to FIG.

The effect of varying the frequency of the clock used to measure shaft velocity in each quadrant of the perturbation period is illustrated by comparing Figures 8a and 8b. The waveforms in Figure 8a are for the case where a 1 MHz clock source is used as the counter clock input. On the other hand, FIG. 8b shows the case where a 10 MHz clock source is used. It is clear from this comparison that the use of a higher frequency clock reduces the variation in injection timing error that affects the perturbation of the control parameters. The effect of clock frequency is even more apparent from the waveform in Figure 8c, which is the result of a computer simulation where the clock oscillator frequency is increased to 100 GHz.

Figure 8d shows the effect of adding a bias to the injection timing. The injection timing is further shifted by about 2 1/2 degrees from the position 10 degrees from the center toward TDC (top dead center). Similarly, the injection timing error is not centered at zero, but is displaced by about 2 1/2 degrees in the negative direction of the crank angle. The waveform in Figure 8d is
This was obtained using a clock frequency of 10MHz.

FIG. 8e shows the case where proportional control based on the curve approximation method is applied at a clock frequency of 10 MHz.
Except for transient errors caused by sudden acceleration and deceleration, most of the fluctuations in the injection timing error have been eliminated. It is clear from the following:

Finally, the waveforms in FIG. 8f show the use of an adaptive control system according to the invention with an open loop control system of the type commonly used in internal combustion engines. The magnitude of the perturbation is approximately 0.025 degree in crank angle, and 10M
As a result of using a Hz clock frequency, injection timing errors are limited to those introduced by perturbations, and the controller operates to eliminate errors over a wide range of speeds.

A method for determining the injection timing characteristics of individual injection devices of a multi-cylinder diesel engine using the optimization method according to the invention will now be described. First, the fuel injection control system is adjusted so that the engine runs at constant fuel consumption. Next, a perturbation is applied to the injection timing of each injection device in synchronization with the rotation of the crankshaft. 1
While one injector is adjusted, the injection timing of the remaining injectors is fixed. According to the perturbation mode,
The injection timing of the injection device under adjustment is advanced in the first half of the perturbation period and delayed by the same amount in the second half, as shown in FIG. The rotational speed of the crankshaft included in the first half and the second half of the perturbation period is the same. Preferably at least two engine periods (four revolutions for a four-stroke engine) are included in each half period of the perturbation period. If the actual flow of fuel from the injection device lags behind MBT (maximum braking torque), advancing the injection timing will increase the engine speed, and delaying the injection timing will decrease the engine speed. Similarly, if the injection timing is ahead of the MBT, the opposite phenomenon will occur and the engine speed will be at the 3rd level.
The change shown in waveform 38 in the figure is made. The control logic of the control mechanism advances the injection timing when the speed change is like waveform 36 and retards the injection timing when the velocity change is like waveform 38. Therefore, the injection timing is always controlled to be close to MBT.

Examining the velocity curve shown in Figure 3, we find that the velocity at the middle part of the perturbation period, i.e. from -2n to +2n, is different from the velocity at both ends of the perturbation period, i.e. from -4n to -2n and +2n.
It can be seen that if the speed is greater than the speed at +4n, the injection timing should be advanced. Conversely, if the velocity at the middle of the perturbation period is lower than the velocity at both ends, the injection timing should be delayed. One way to implement this logic is to determine the error signal using error equation (1). If the value of E is positive,
This indicates that the injection timing is to be advanced, and a negative value indicates that the injection timing is to be delayed. The correction amount is a fixed amount, and is applied in the forward direction when the value of E is positive, and in the backward direction when the value of E is negative. It is also possible to make the correction amount proportional to the magnitude of the error signal E.

For this device to work properly, the perturbation period must be synchronized with the engine's ignition pulse. If synchronization is not achieved, the MBT (maximum braking torque) detection circuit will not operate properly. This is because speed changes caused by the influence of engine ignition pulses that change as a result of perturbing the injection timing of individual injectors cannot be accurately captured. Additionally, since only one injector is being perturbed during adjustment, the engine must complete at least one complete revolution in each quarter of the perturbation period. This is because the injector being adjusted must operate reliably at least once during each quadrant.

As we have explained in detail about the equipment used to optimize engine ignition timing, individual injection devices can be adjusted using equipment made up of individual digital logic elements or microprocessor equipment. I don't mind. In either case, the perturbation period is initiated by a pulse generated when a mark on the flywheel passes past the stationary detector. The timer is also started by the detection of the landmark,
Operation continues until two revolutions, ie, the mark on the flywheel passes the detector for the second time. This first quadrant average time is used for the Δt ₁ calculation of the error equation described above. The time during the next two revolutions is similarly measured to determine Δt ₂ . The landmark passing signal at the end of the second quarter is also used as a signal to retard the ignition timing during the second half of the perturbation period. (See Figure 3) Remaining 4 that occurs during the perturbation period
The time required for rotation is also measured in a similar manner, △t ₃
and △t ₄ are determined. These four rotational time components are used to calculate (E), and at the end of the perturbation period, it is determined whether to lead or lag as a correction signal. This process continues until the MBT (maximum braking torque) ignition timing is obtained. Both the discrete logic device and the microprocessor control program incorporate suitable decision circuitry to indicate when the device has reached MBT. This ignition timing is averaged over several cycles and recorded to calculate the MBT ignition timing for the injector being adjusted. A similar process is performed for each engine injector.

Once each injector is processed by the control algorithm according to the present invention, the MBT of each injector
Ignition timing is translated into the relative relationship of the injectors to each other. This interaction is reflected in electrical and mechanical delay characteristics. Knowing the individual values makes it possible to initialize or adjust the control device of the injector to the characteristics of the respective injector.

The procedure described above can be performed manually or automatically whenever readjustment of the device is required. However, once the adjustment is made, the system is switched to normal injection timing control mode. At this point, differences in injection timing between the cylinders have already been eliminated in the previous adjustment process of the individual injection devices.

Similar to the method explained above, the bias value is introduced as explained earlier to check the operating state of the device.
It is also possible to deviate from the MBT by a predetermined value, and this can be done in the process of determining the various variables during the adjustment of the injection system of a diesel engine. In this case, the velocity vs. injection timing curve becomes somewhat steeper because the injection timing deviates from the MBT.The bias is used to obtain a large value for (E), which increases the sensitivity of the device. It becomes easier to use.

The invention has been described in considerable detail in accordance with patent law;
We have provided those skilled in the art with the information necessary to understand the concepts, configure, and utilize these devices as needed. However, it should be noted that the present invention can also be implemented with different devices and that various modifications can be made to the devices and processing procedures without going beyond the scope of the present invention.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an adaptive control system according to the present invention; Fig. 2 is a waveform diagram showing normal speed changes within one engine cycle of a six-cylinder internal combustion engine; Fig. 3 is a diagram of one engine of a six-cylinder internal combustion engine. A waveform diagram showing a "perturbation" cycle within a cycle and the resulting speed change; Figure 4 is a logic circuit diagram for implementing the invention using discrete logic elements; Figure 5 is a control according to the invention. A block diagram of the microprocessor programmed to execute the algorithm; Figures 6a to 6c are flowcharts of what is programmed into the microprocessor shown in Figure 5; Figures 7a and 7b are ignition Waveform diagrams showing timing and timing errors as a function of engine speed using prior art asynchronous perturbation electronic controllers; Figures 8a to 8f.
The figure shows ignition timing and timing error as a function of engine speed, and is a waveform diagram when bias conditions and clock conditions are varied using the electronic control device according to the present invention. Explanation of symbols, 10... Engine, 12... Output shaft,
16...Flywheel, 18...Mark, 20...
...detector, 22 ... control setting, 34 ... perturbation waveform, 36, 38 ... shaft speed, 44, 46, 48,
50...AND gate, 58, 60, 62, 64
... Counter, 66, 68 ... Adder, 70 ... Subtractor, 80 ... Central processing unit, 82, 84 ...
...Storage device, 90, 92, 94, 96...I/O
port.

Claims (1)

[Claims] 1. In an electronic adaptive control device for optimizing the performance of an engine under given set value conditions of performance control parameters of the engine: (a) for the engine; (b) a shaft rotation detection device coupled to the shaft rotation detection device for detecting rotation of the output shaft of the engine relative to a predetermined reference point; a device that changes the set value symmetrically before and after the set value in synchronization with the rotation of the output shaft; (c) connected to the shaft rotation detection device, that changes the set value symmetrically before and after the set value; (d) a speed setting device that divides a period in which the output shaft is changed into a plurality of sections and calculates an average rotational speed of the output shaft in the plurality of sections; Determine the average rotational speed of the output shaft and the average rotational speed of the output shaft in another section of the period, and calculate the deviation of the average rotational speed of the output shaft in the two sections, which indicates the degree of acceleration of the engine. An electronic adaptive control device comprising: a calculation device; and (e) a device for modifying the given setpoint according to the value of the deviation. 2. Each of the sections in which the set value is symmetrically changed before and after the set value has the same number of cylinder ignition pulses of the engine, and the periods of the plurality of sections are synchronized with the cylinder ignition pulses. An electronic adaptive control device according to claim 1, characterized in that: 3. The electronic adaptive control device according to claim 1, wherein the shaft rotation detection device includes a device that outputs one electric pulse every 360 degrees when the output shaft rotates. . 4 The calculation device converts the setting value of the engine into MBT.
2. The adaptive control device according to claim 1, further comprising a bias device that corrects the deviation value so as to deviate it from the (maximum braking torque) setting by a predetermined value. 5. In an electronic adaptive control device for optimizing the performance of a motor under given set value conditions of performance control parameters of the motor: (a) coupled to the motor and controlling the performance of the motor; a shaft rotation detection device for detecting the rotation of the output shaft; (b) coupled to the shaft rotation detection device for synchronizing a given set value of a performance control parameter of the engine with the rotation of the output shaft; (c) a device that is connected to the shaft rotation detection device and changes the set value before and after the set value, the period of change of the set value being divided into four sections; (d) a speed measuring device for determining the average rotation time of the output shaft; (d) the average rotation time of the output shaft in one section of the period divided into the four sections and the average rotation time of the output shaft in another section of the period; (e) a device for correcting the given set value according to the value of the deviation; and (e) a device for correcting the given set value according to the value of the deviation. Device. 6. An equal number of engine cylinder ignition pulses are included in each of the intervals in which the set value is alternately changed before and after the set value, and the periods of the four intervals are synchronized with the cylinder ignition pulses. An electronic adaptive control device according to claim 5, characterized in that: 7. The electronic adaptation according to claim 1, wherein the shaft rotation detection device includes a device that outputs one electric pulse for every 360 degrees of rotation angle when the output shaft rotates. Control device. 8. In a method for optimizing the performance of an engine under given set value conditions of performance control parameters of the engine: (a) detecting rotation of the output shaft of the engine; (b) ) changing a given set value of a performance control parameter of the engine symmetrically before and after the set value in synchronization with the rotation of the output shaft; (c) changing the set value symmetrically before and after the set value; Divide the period in which the output shaft is changed into four sections, and find the average rotational speed of the output shaft in the four sections; Determine the average rotational speed and the average rotational speed of the output shaft in another section of the period, and calculate the deviation of the average rotational speed of the output shaft in both sections; (e) convert the given setting value to the A method for optimizing the performance of a mover consisting of a procedure for adjusting it as a function of deviation. 9. In a method for adjusting injection timing control of an internal combustion engine: (a) detecting rotation of an output shaft of the internal combustion engine; (b) adjusting a given set value of the injection timing control in synchronization with the rotation of the output shaft; cyclically advancing or retarding the injection start timing of at least one of the fuel injection valves of the internal combustion engine before or after that value; (c) a period during which the injection start timing is cyclically advanced or retarded; Divide into a plurality of sections and find the average rotational speed of the output shaft in the plurality of sections; (d) calculate the average rotational speed of the output shaft in a certain section of the period divided into the plurality of sections; (e) adjusting the given set value as a function of the deviation; A method for adjusting injection timing control for an internal combustion engine, which consists of steps. 10 In a method for adjusting injection timing control of a plurality of fuel injection valves of a multi-cylinder internal combustion engine: (a) detecting rotation of an output shaft of the internal combustion engine; (b) adjusting the injection timing in synchronization with the rotation of the output shaft; (c) individually advancing or retarding a set value of the injection start timing given the timing control for each of the plurality of fuel injection valves of the internal combustion engine symmetrically and periodically before and after that value; Divide the period in which the injection start timing is periodically advanced or delayed into four sections, and find the average rotation time of the output shaft in the four sections; (d) The period divided into the four sections. (e ) Adjust the given set value according to the value of the deviation; (f) Record the predetermined injection start timing to obtain the maximum braking torque; (g) From (a) to (f) above. A method for adjusting injection timing control for an internal combustion engine, comprising repeating the procedure for each of the fuel injection valves.