ELECTRONIC CONTROL METHOD FOR THROTTLE AND ELECTRONIC CONTROL THROTTLE DEVICE

Abstract

An electronic control method for a throttle performed by an electronic control throttle device is disclosed. The electronic control method includes: generating, by the electronic control section, the control signal for the throttle with a sum of a proportional torque and an integral torque as a value of a torque command, by calculating an engine speed deviation from a difference between a calculated or input engine speed and an input engine speed command; calculating an engine rotational angular acceleration based on the engine speed; obtaining the proportional torque from a product of the engine speed deviation and a predetermined coefficient; and obtaining the integral torque by integrating the product of the engine speed deviation and the predetermined coefficient.

Claims

1. An electronic control method for a throttle performed by an electronic control throttle device in which an electronic control section performs control to open and close the throttle while generating a control signal based on an input data signal, the electronic control method comprising: generating, by the electronic control section, the control signal for the throttle with a sum of a proportional torque and an integral torque as a value of a torque command, by calculating an engine speed deviation from a difference between a calculated or input engine speed and an input engine speed command, calculating an engine rotational angular acceleration based on the engine speed, obtaining the proportional torque from a product of the engine speed deviation and a predetermined coefficient, and obtaining the integral torque by integrating the product of the engine speed deviation and the predetermined coefficient, wherein the control signal for the throttle is generated to control an intake air pressure by changing each coefficient used for calculating the proportional torque and the integral torque that are appropriate for each of operating states of four regions determined according to a combination of a deviation between the calculated or input engine speed and the input engine speed command, and the engine rotational angular acceleration, and introducing a smoothing torque that suppresses a discontinuous torque change to continuously change the torque command.

2. The electronic control method for a throttle according to claim 1, wherein the operating states of the four regions are regions A, B, C, and D divided according to the following conditions:
Region A: ω.sub.ref(K)−ω(K)≤0 and ω′(K)<0
Region B: ω.sub.ref(K)−ω(K)>0 and ω′(K)<0
Region C: ω.sub.ref(K)−ω(K)≤0 and ω′(K)≥0
Region D: ω.sub.ref(K)−ω(K)>0 and ω′(K)≥0   [Expression 1] where ωref(K) represents the engine speed command of the K-th sample, ω(K) represents the engine speed, and ω′(K) represents the engine rotational angular acceleration.

3. The electronic control method for a throttle according to claim 1, wherein the smoothing torque is a product of a deviation between coefficients for calculating the proportional torque before and after a change in operating state, and the engine speed deviation.

4. An electronic control throttle device comprising: a throttle to which an actuator is attached; and an electronic control section which performs control to open and close the throttle via the actuator while generating a control signal based on an input data signal, wherein the electronic control section includes a speed deviation calculation section that calculates an engine speed deviation from a difference between an engine speed and an engine speed command, a rotational angular acceleration calculation section that calculates an engine rotational angular acceleration based on the engine speed, a proportional torque computation section that obtains a proportional torque from a product of the engine speed deviation and a predetermined coefficient, and an integral torque computation unit that obtains an integral torque by integrating the product of the engine speed deviation and the predetermined coefficient, wherein the electronic control throttle device is configured to generate, via the electronic control section, the control signal for the throttle with a sum of the proportional torque and the integral torque as a value of a torque command, by calculating the engine speed deviation from the difference between the engine speed and the engine speed command, calculate the engine rotational angular acceleration based on the engine speed, obtain the proportional torque from the product of the engine speed deviation and the predetermined coefficient, and obtain the integral torque by integrating the product of the engine speed deviation and the predetermined coefficient, and wherein the control signal for the throttle is generated to control an intake air pressure by changing each coefficient used for calculating the proportional torque and the integral torque that are appropriate for each of operating states of four regions determined according to a combination of a deviation between the calculated or input engine speed and the input engine speed command, and the engine rotational angular acceleration, and introducing a smoothing torque that suppresses a discontinuous torque change to continuously change the torque command.

5. The electronic control throttle device according to claim 4, wherein the operating states of the four regions are regions A, B, C, and D divided according to the following conditions:
Region A: ω.sub.ref(K)−ω(K)≤0 and ω′(K)<0
Region B: ω.sub.ref(K)−ω(K)>0 and ω′(K)<0
Region C: ω.sub.ref(K)−ω(K)≤0 and ω′(K)≥0
Region D: ω.sub.ref(K)−ω(K)>0 and ω′(K)≥0 where ωref(K) represents the engine speed command of the K-th sample, ω(K) represents the engine speed, and ω′(K) represents the engine rotational angular acceleration.

6. The electronic control throttle device according to claim 4, wherein the smoothing torque is a product of a deviation between coefficients for calculating the proportional torque before and after a change in operating state, and the engine speed deviation.

7. The electronic control method for a throttle according to claim 2, wherein the smoothing torque is a product of a deviation between coefficients for calculating the proportional torque before and after a change in operating state, and the engine speed deviation.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0020] FIG. 1 is a simplified configuration diagram of an electronic control throttle device according to an embodiment of the present invention;

[0021] FIG. 2 is a functional block diagram illustrating control contents of the electronic control throttle device according to the embodiment illustrated in FIG. 1;

[0022] FIG. 3 is a graph illustrating a change in torque command in a control example of the electronic control throttle device of FIG. 1;

[0023] FIG. 4 is a simplified configuration diagram of a conventional electronic control throttle device;

[0024] FIG. 5 is a functional block diagram illustrating control contents of the conventional electronic control throttle device illustrated in FIG. 4; and

[0025] FIG. 6 is a graph illustrating a change in torque command in a control example of the conventional electronic control throttle device illustrated in FIG. 4.

DETAILED DESCRIPTION

[0026] FIG. 1 schematically illustrates a functional configuration of an electronic control throttle device that performs an electronic control method for a throttle according to a preferred embodiment of the present invention. The electronic control throttle device has substantially the same configuration as the conventional electronic control throttle device illustrated in FIG. 4, and includes a throttle 2 to which an actuator (not illustrated) is attached, and an electronic control unit 1, which is an electronic control section that performs control to open and close the throttle 2. The electronic control unit 1 automatically performs control to open and close the throttle 2 while generating a control signal by a predetermined calculation method based on various data signals input thereto.

[0027] In addition, the electronic control unit 1 includes, as sections functionally configured by software stored in a storage section (not illustrated), a speed calculation section 11 that calculates an engine speed, a speed deviation calculation section 12 that calculates an engine speed deviation, a rotational angular acceleration calculation section 13 that calculates an engine rotational angular acceleration, a proportional torque computation section 14 that obtains a proportional torque, and an integral torque computation section 15 that obtains an integral torque.

[0028] Next, the control performed by the electronic control unit 1 will be described in detail with reference to FIGS. 1 and 3.

[0029] First, in the present embodiment, the speed calculation section 11 calculates the engine speed from a cycle of a pulse signal input from a crank pulse sensor (not illustrated), the speed deviation calculation section 12 calculates the engine speed deviation from a difference between the engine speed and the engine speed command (target speed), and the rotational angular acceleration calculation section 13 calculates the engine rotational angular acceleration based on the engine speed.

[0030] Then, the proportional torque computation section 14 computes a product of the engine speed deviation and a predetermined coefficient to obtain a proportional torque, and the integral torque computation section 15 performs computation of integrating a value obtained by subtracting a product of the engine rotational angular acceleration and a predetermined coefficient from the product of the engine speed deviation and a predetermined coefficient to obtain an integral torque, thereby generating a control signal for the throttle 2 using a sum of the proportional torque and the integral torque as a value of a torque command. In particular, for the contents of the control performed by the electronic control unit 1, the operating state of the engine is divided into four regions A, B, C, and D under the following conditions, and a control coefficient varies for each region to further change the configuration of an integral control system.

Region A: ω.sub.ref(K)−ω(K)≤0 and ω′(K)<0

Region B: ω.sub.ref(K)−ω(K)>0 and ω′(K)<0

Region C: ω.sub.ref(K)−ω(K)≤0 and ω′(K)≥0

Region D: ω.sub.ref(K)−ω(K)>0 and ω′(K)≥0   [Expression 4] [0031] where ωref(K) represents the engine speed command of the K-th sample, ω(K) represents the engine speed, and ω′(K) represents the engine rotational angular acceleration.

[0032] More specifically, the engine speed command of the K-th sample is defined as ω.sub.ref(K), the engine speed is defined as ω(K), the engine rotational angular acceleration is defined as ω′(K), a variable proportional coefficient used for proportional control is defined as K.sub.vP(K), and a variable integral coefficient used for integral control is defined as K.sub.vI(K), and the variable proportional coefficient K.sub.vP(K) and the variable integral coefficient K.sub.vI(K) in the regions A, B, C, and D are calculated as follows.

Region A: K.sub.vP(K)=K.sub.vPA(K), K.sub.vI(K)=K.sub.vIA(K)

Region B: K.sub.vP(K)=K.sub.vPB(K), K.sub.vI(K)=K.sub.vIB(K)

Region C: K.sub.vP(K)=K.sub.vPC(K), K.sub.vI(K)=K.sub.vIC(K)

Region D: K.sub.vP(K)=K.sub.vPD(K), K.sub.vI(K)=K.sub.vID(K)   [Expression 5]

[0033] Then, the proportional torque is defined as Torq.sub.Pref(K), a smoothing torque is defined as ΔTorq.sub.ref(K), the integral torque is defined as Torq.sub.Iref(K), the torque command is defined as Torq.sub.ref(K), and a sampling time is defined as T.sub.S, and the proportional torque, the smoothing torque, the integral torque, and the torque command are calculated by the following Expressions (1) to (4).

[0034] Next, the electronic control method for the throttle of the present embodiment will be described while comparing a graph illustrating a change in torque command indicating the electronic control method for the throttle of the present embodiment illustrated in FIG. 3 with a graph illustrating a change in torque command in a control example of the conventional electronic control throttle device illustrated in FIG. 6.

[0035] Focusing on a change in engine speed until the engine speed converges to ω.sub.ref(K)−ω(K)=0 after the load is applied and ω.sub.ref(K)−ω(K)>0, and a change in engine speed until the engine speed converges to ω.sub.ref(K)−ω(K)=0 after the load is removed and ω.sub.ref(K)−ω(K)≥0, in a case of the conventional example illustrated in FIG. 6, only the region L exists after ω.sub.ref(K)−ω(K)>0. Therefore, a state in which the engine speed decreases and a state in which the engine speed increases cannot be distinguished from each other, and appropriate switching of the control coefficient cannot be performed, as a result of which fluctuation occurs.

[0036] On the other hand, in the present embodiment illustrated in FIG. 3, after ω.sub.ref(K)−ω(K)>0 and the operating state enters the region B, K.sub.vPB (the variable proportional coefficient for the region B) is increased to prevent a decrease in engine speed, and K.sub.vPC (the variable proportional coefficient for the region C) is decreased to make the engine speed slowly converge to ω.sub.ref(K)−ω(K)=0 when the operating state enters the region C.

[0037] Similarly, also for a change in engine speed until the engine speed converges to ω.sub.ref(K)−ω(K)=0 after the load is removed and ω.sub.ref(K)−ω(K)≤0, in a case of the conventional example illustrated in FIG. 6, only the region H exists after ω.sub.ref(K)31 ω(K)≤0. Therefore, a state in which the engine speed increases and a state in which the engine speed decreases cannot be distinguished from each other, and appropriate switching of the control coefficient cannot be performed, as a result of which fluctuation occurs.

[0038] On the other hand, in the present embodiment illustrated in FIG. 3, after ω.sub.ref(K)−ω(K)≤0 and the operating state enters the region D, K.sub.cPD (the variable proportional coefficient for the region D), which is the variable proportional coefficient for the region D, is increased to prevent rising of the engine speed, and K.sub.vPA (the variable proportional coefficient for the region A) is decreased to make the engine speed slowly converge to ω.sub.ref(K)−ω(K)=0 when the operating state enters the region A.

[0039] Furthermore, in the present embodiment, since a difference {K.sub.vP(K)−K.sub.vP(K−1)} (ω.sub.ref(K)−ω(K)) in torque command that has discontinuously changed at the time of region change is added to Torq.sub.ref(K) as ΔTorq.sub.ref(K), the discontinuous change of the torque command is suppressed, and the engine speed does not fluctuate and converges to the engine speed command.

[0040] As described above, according to the present invention, it is possible to suppress the fluctuation of the engine speed when, for example, a load is applied, by changing the proportional control coefficient and the integral control coefficient of the torque command in the throttle control to appropriate values depending on the region of the engine operating state, and it is possible to prevent a failure from occurring in the operating situation by continuously changing the torque command by the smoothing torque.