CN110809668B - Engine control device and engine control method - Google Patents

Abstract

An engine control device (1) is provided with: an engine (10) that drives a drive wheel (11); a three-phase starter generator (12) connected to a crankshaft (13) of the engine (10); and a control unit (40) that controls the engine (10) and the three-phase starter generator (12); the control unit (40) is configured so that, when a slip of the drive wheels (11) is detected, the energization control mode of the three-phase starter generator (12) can be set to a short-circuit braking mode in which the output terminals (12a) of the three-phase starter generator (12) are short-circuited to generate a braking force.

Description

Engine control device and engine control method

Priority is claimed in the present application based on japanese patent application No. 2017-129140, filed on 30/6/2017, the entire contents of which are incorporated herein by reference.

Technical Field

The present invention relates to a control technique for an engine that drives a drive wheel.

Background

Patent document 1 discloses a drive wheel slip control device (hereinafter, simply referred to as "control device") mounted on a vehicle. The control device is configured to perform control for suppressing the output of the engine, such as throttle control, fuel cut control, and ignition delay control, when a slip state of the drive wheels is detected. Therefore, according to this control device, the torque of the drive wheels can be reduced by suppressing the output of the engine without using an expensive brake system for performing brake control.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 2524246

Disclosure of Invention

However, since the slip of the drive wheels occurs regardless of the stroke of the engine, when the output suppression control of the engine is performed depending on the stroke of the engine, the timing at which the control can be executed is limited, and there is a problem that the responsiveness of the control is deteriorated. For example, since both the fuel cut control and the ignition delay control are synchronized with the stroke of the engine, these controls cannot be performed from the detection of the slip state of the vehicle to the timing of the next ignition execution, and a time delay may occur until the torque of the drive wheels can be reduced.

The present invention has been made in view of the above problems, and an object thereof is to provide an engine control technique capable of effectively improving the responsiveness of control for reducing torque when a slip of a drive wheel occurs.

One aspect of the present invention is an engine control device including: an engine that drives a drive wheel; a three-phase starter generator coupled to a crankshaft of the engine; and a control unit configured to control the engine and the three-phase starter generator, wherein the control unit is configured to set an energization control mode of the three-phase starter generator to a short-circuit braking mode in which output terminals of the three-phase starter generator are short-circuited to generate a braking force when the slip of the drive wheel is detected, and the control unit is configured to set the energization control mode of the three-phase starter generator to the short-circuit braking mode when a predetermined setting start condition is satisfied when the slip of the drive wheel is detected.

Another aspect of the present invention is an engine control method including: a slip detection step of detecting a slip of a drive wheel driven by an engine; and a short-circuit braking mode setting step of setting, when the slip detection is detected in the slip detection step and a predetermined setting start condition is satisfied, an energization control mode of a three-phase starter generator connected to a crankshaft of the engine to a short-circuit braking mode in which an output terminal of the three-phase starter generator is short-circuited to generate a braking force.

Effects of the invention

According to the engine control device and the engine control method described above, when a slip of the drive wheels is detected, the energization control mode of the three-phase starter generator can be set to the short-circuit braking mode in which the output terminals of the three-phase starter generator are short-circuited to generate the braking force. This can reduce the torque that increases the load on the crankshaft when the slip of the drive wheels occurs.

In this case, unlike the control of the three-phase starter generator, which is limited in timing and can be executed depending on the stroke of the engine, such as the engine output suppression control for suppressing the output of the engine, the control of the three-phase starter generator is asynchronous without depending on the stroke of the engine, and can be set independently of the stroke of the engine.

Therefore, by setting the energization control mode of the three-phase starter generator to the short-circuit braking mode, it is possible to reduce the torque at the time of occurrence of a slip of the drive wheels without a time delay as compared with the engine output suppression control.

As described above, according to the above-described aspects, the responsiveness of the control for reducing the torque at the time of occurrence of a slip of the drive wheels can be improved.

In the claims, the numerals in parentheses indicate correspondence with specific means described in the embodiments described below, and do not limit the technical scope of the present invention.

The above object, other objects, features and advantages of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings.

Drawings

Fig. 1 is a schematic diagram of an engine control device according to embodiment 1.

Fig. 2 is a schematic diagram of the three-phase starter generator and inverter of fig. 1.

Fig. 3 is a flowchart of the slip suppression control according to embodiment 1.

Fig. 4 is a diagram for explaining the timing of detecting a slip of the drive wheels.

Fig. 5 is a diagram for explaining the detection timing of the slip of the drive wheels corresponding to the stroke of the engine.

Fig. 6 is a diagram for explaining an operation when the energization control mode of the three-phase starter generator is set to the short-circuit braking mode.

Fig. 7 is a diagram for explaining a flow of current when the energization control mode of the three-phase starter generator in fig. 2 is set to the short-circuit braking mode.

Fig. 8 is a flowchart of the slip suppression control according to embodiment 2.

Detailed Description

Hereinafter, an embodiment of an engine control device and an engine control method for controlling an engine of a vehicle will be described with reference to the drawings.

(embodiment mode 1)

As shown in fig. 1, an engine control device 1 according to embodiment 1 is mounted on a vehicle, and includes an engine 10 as an internal combustion engine that drives drive wheels 11, a three-phase starter generator 12, and a control unit 40 that controls the engine 10 and the three-phase starter generator 12.

Although not particularly shown, the engine 10 is configured as a 4-stroke engine having 1 cylinder, that is, a so-called "single cylinder engine". The interval of work in the engine stroke of this engine 10 is 720 °.

The crankshaft 13 is a shaft for converting the output of the engine 10 into rotational driving force, and is coupled to an axle 15 of the drive wheel 11 via a gear mechanism 14. Therefore, the rotational driving force of the crankshaft 13 is transmitted to the axle 15 via the gear mechanism 14, and the rotational driving force of the axle 15 is transmitted to the crankshaft 13 via the gear mechanism 14.

The control unit 40 includes a rotation speed/crank angle position calculation unit 41, a vehicle speed calculation unit 42, a slip determination unit 43, a TRC control amount determination unit 44, an ignition control unit 45, an injection control unit 46, and a generator control unit 47.

The vehicle speed sensor 16 is a sensor that detects a vehicle speed based on the rotation of the axle 15. The information detected by the vehicle speed sensor 16 is transmitted to a vehicle speed calculation unit 42 of the control unit 40, and the vehicle speed calculation unit 42 calculates the vehicle speed based on the information.

A rotor (not shown) of the three-phase starter generator 12 is directly coupled to the crankshaft 13. The three-phase starter generator 12 is a three-phase AC generator that combines 3-system (U-phase, V-phase, W-phase) single-phase AC with mutually shifted phases of current or voltage, and is a generator (ACG start) that serves as both a starter motor for starting and an AC generator (AC generator). That is, the three-phase starter generator 12 functions as a starter motor by rotationally driving the crankshaft 13 in the same direction as after the engine 10 is started when the engine 10 is started, and also functions as a generator that generates power by the rotational driving force generated by the crankshaft 13 after the engine 10 is started.

In the following description, the three-phase starter generator 12 is simply referred to as "generator 12" for convenience.

The generator 12 is controlled by a generator control unit 47 of the control unit 40. The generator control unit 47 is configured to be able to set the energization control mode of the generator 12 to a short-circuit braking mode in which the output terminals (output terminals 12a in fig. 2) are short-circuited to generate a braking force, although details will be described later.

The battery 17 is a chargeable and dischargeable battery, and is electrically connected to the generator 12 via an inverter circuit 18 for performing power conversion between ac and dc. Therefore, the ac power generated by the generator 12 is converted into dc power by the inverter circuit 18 and then supplied to the battery 17.

As shown in fig. 2, the inverter circuit 18 includes a plurality of semiconductor elements 18a, and a drive circuit 18b that controls the opening and closing of the plurality of semiconductor elements 18a in accordance with a control signal from the generator control unit 47 of the control unit 40, and is connected to a stator coil U, V, W of the generator 12.

The semiconductor element 18a is formed of, for example, a MOSFET as a switching element. The plurality of semiconductor elements 18a are classified into upper arm semiconductor elements SW1, SW2, and SW3 of three phases on the positive side electrically connected to the positive power terminal, and lower arm semiconductor elements SW4, SW5, and SW6 of three phases on the negative side electrically connected to the negative power terminal.

The drive circuit 18b controls the opening and closing of the plurality of semiconductor elements 18a so that the generator 12 functions as a three-phase synchronous motor when the engine 10 is started. On the other hand, after the engine 10 has operated stably and has performed full work, the drive circuit 18b controls the plurality of semiconductor elements 18a to be opened and closed so that the generator 12 functions as a three-phase synchronous generator.

Returning to the description of fig. 1, the rotation speed sensor 19 is a sensor for detecting the rotation speed of the engine 10. The information detected by the rotation speed sensor 19 is transmitted to the rotation speed/crank angle position calculation unit 41 of the control unit 40, and based on the information, the rotation speed/crank angle position calculation unit 41 calculates the rotation speed and the crank angle position, respectively.

The spark plug 20 includes an electrode portion (not shown) for generating spark discharge at its tip, and the electrode portion is exposed to a combustion chamber of the engine 10. The ignition plug 20 is electrically connected to an ignition control unit 45 of the control unit 40 via an ignition device (not shown) including an ignition coil and the like, and is controlled in accordance with a control signal from the ignition control unit 45. That is, the ignition device operates in accordance with a control signal from the ignition control unit 45, and spark discharge is generated in the electrode unit of the spark plug 20.

An intake system 30 of the engine 10 includes an injector 32 for injecting fuel into an intake pipe 31 and a throttle valve 33 capable of adjusting a passage cross-sectional area (flow passage area). The injector 32 is electrically connected to an injection control unit 46 of the control unit 40, and is controlled in accordance with a control signal from the injection control unit 46. The opening degree of the throttle valve 33 is detected by a position sensor 34. The information detected by the position sensor 34 is transmitted to the control unit 40.

The slip determination unit 43 of the control unit 40 is configured to perform a process of determining a slip of the drive wheels 11 based on the calculation results of the rotation speed/crank angle position calculation unit 41 and the vehicle speed calculation unit 42.

The TRC control amount determining unit 44 of the control unit 40 is configured to determine a control amount regarding the ignition timing of the engine 10, a control amount regarding the fuel injection of the engine 10, and a control amount regarding the energization control of the generator 12, based on the calculation results of the rotation speed/crank angle position calculating unit 41 and the vehicle speed calculating unit 42.

Next, an engine control method according to embodiment 1 will be described. The engine control method is a control method using the slip suppression control performed by the control unit 40. As shown in the flowchart of fig. 3, the slip suppression control includes steps from step S101 to step S109.

Further, other steps may be added to the flowchart as necessary, or 1 step may be divided into a plurality of steps.

Step 101 is a slip detection step of detecting a slip of the drive wheels 11 driven by the engine 10. This step 101 is executed by the slip determination unit 43. In this step 101, it is determined that the drive wheels 11 are slipping when the slip determination flag is present (when the flag is present), and it is determined that no slip is detected when the slip determination flag is not present (when the flag is absent).

If it is determined in step S101 that the drive wheel 11 is slipping, the process proceeds to step S102, otherwise, the process from step S102 to step S108 is skipped, and the process proceeds to step S109. That is, this step S101 is continued until it is determined that the slip of the drive wheels 11 is detected.

The condition for setting the slip determination flag includes, for example, a case where the degree of change in the vehicle speed detected by the vehicle speed sensor 16 exceeds a preset threshold value, that is, a case where the vehicle speed changes rapidly in a situation such as acceleration, constant-speed running, or deceleration.

For example, as shown in fig. 4, the throttle operation is increased from time t1, the engine speed is increased from time t2, and the vehicle speed is likely to change rapidly as the vehicle speed increases. Therefore, the slip determination flag is set (flagged state) during the period from the time t3 when the vehicle speed increases to the time t4 when the slip of the drive wheels 11 occurs.

Step S102 is a control parameter determining step of determining the ignition timing retardation amount based on the slip state of the drive wheels 11. The ignition timing retardation amount is a retard correction amount as a control parameter when executing the engine output suppression control synchronized with the stroke of the engine 10, that is, the ignition retardation control. This step S102 is executed by the TRC control amount determination unit 44.

In this step S102, first, a target engine torque for ignition control is calculated from a torque request value derived based on control logic for ensuring the stability of the vehicle at the time of occurrence of a slip. The calculated target engine torque is converted into a retard correction amount and reflected in the ignition period.

Step S103 is a step of determining whether or not the crank angle from the ignition of the engine 10 is smaller than a predetermined angle at the time of detection of a slip of the drive wheels 11 at step S102. This step S103 is executed by the rotation speed/crank angle position calculation unit 41.

In step S103, if it is determined that the crank angle from the ignition of the engine 10 is smaller than the predetermined angle, the process proceeds to step S104, otherwise, the process from step S104 to step S106 is skipped, and the process proceeds to step S107.

Here, when the crank angle is smaller than the predetermined angle, the degree of progression of the stroke after ignition of the engine 10 is small, and when the crank angle is larger than the predetermined angle, the degree of progression of the stroke after ignition of the engine 10 is large. Therefore, according to this step S103, it is possible to achieve the object of relatively determining whether the degree of progress of the stroke after ignition of the engine 10 is large at the time of the slip detection.

In order to achieve this object, in step S103, the elapsed time may be measured instead of the crank angle and used as a parameter for determination. That is, this step S103 may be replaced with a step of determining whether or not the elapsed time from the ignition of the engine 10 is shorter than a predetermined time.

Step S104 is a step of determining whether or not the crank angle until the next ignition of engine 10 is larger than a predetermined angle. The rotation speed/crank angle position calculating unit 41 executes this step S104.

If it is determined in step S104 that the crank angle to the next ignition of the engine 10 is larger than the predetermined angle, the routine proceeds to step S105, otherwise the routine skips from step S105 to step S106 and proceeds to step S107.

Here, in the slip detection, when the crank angle is larger than the predetermined angle, the time until the next ignition of the engine 10 is long, and when the crank angle is smaller than the predetermined angle, the time until the next ignition of the engine 10 is short. Therefore, according to this step S104, it is possible to achieve the object of relatively determining whether or not the time until the next ignition of the engine 10 is long.

In order to achieve this object, in step S104, the elapsed time may be measured instead of the crank angle and used as a parameter for determination. That is, step S104 may be replaced with a step of determining whether or not the time until the next ignition of engine 10 is longer than a predetermined time.

The energization control mode of the generator 12 is set to the short-circuit braking mode in step S105, and the ignition delay control is executed in step S107.

Incidentally, when the slip of the drive wheels 11 is detected, if the degree of progress of the stroke after ignition of the engine 10 is relatively small and the time until the next ignition is relatively long (yes in both step S103 and step S104), a delay in time occurs until the ignition delay control is executed. As shown in fig. 5, for example, when the time t3 at which the slip of the drive wheels 11 occurs is the power stroke of the engine 10, the delay time corresponding to the crank angle of 720 ° occurs at the maximum until the ignition delay control is executed.

Therefore, in the present embodiment, the control unit 40 is configured to set the energization control mode of the generator 12 to the short-circuit braking mode in which the output terminals 12a of the generator 12 are short-circuited to generate the braking force when the predetermined setting start condition is satisfied when the slip of the drive wheels 11 is detected.

As the "predetermined setting start condition" described here, a condition may be adopted in which, when the slip of the drive wheels 11 is detected, the degree of progress of the stroke after ignition of the engine 10 is small (the crank angle Ta in fig. 5 is smaller than the predetermined angle) and the time until the next ignition is long (the crank angle Tb in fig. 5 is larger than the predetermined angle). Therefore, steps S103 and S104 are determination steps for determining that the predetermined setting start condition is satisfied when the degree of progress of the stroke after ignition of the engine 10 is small and the time until the next ignition is long when the slip of the drive wheels 11 is detected.

When the predetermined setting start condition is satisfied, it can be determined that there is time until the ignition delay control of the engine 10 is executed. Therefore, in order to quickly cope with the slip of the drive wheels 11 at this timing, it is preferable to set the energization control mode of the generator 12 to the short-circuit braking mode prior to the ignition delay control.

On the other hand, when the degree of progress of the stroke of the engine after ignition is large (the crank angle Ta in fig. 5 is larger than the predetermined angle) or when the time until the next ignition is short (the crank angle Tb in fig. 5 is smaller than the predetermined angle), the energization control mode of the generator 12 is not set to the short-circuit braking mode, and the ignition retard control having a high effect of reducing the torque of the drive wheels 11 is promptly executed in step S107.

Step S105 is a short-circuit braking mode setting step of setting the energization control mode of the generator 12 to the short-circuit braking mode when the setting start condition is satisfied when the slip is detected. This step S105 is executed by the generator control unit 47.

Specifically, as shown in fig. 6, the energization control mode of the generator 12 is switched from the normal mode to the short-circuit braking mode. In this short brake mode, all of the upper arm semiconductor elements SW1, SW2, SW3 are switched to be off or maintained in an off state, and all of the lower arm semiconductor elements SW4, SW5, SW6 are switched to be on or maintained in an on state.

As shown in fig. 7, if the generator 12 is set to the short-circuit braking mode, the output terminals 12a of the generator 12 can be short-circuited to return a current to the generator 12. At this time, the load of the crankshaft 13 connected to the generator 12 is increased, whereby the driving wheels 11 can generate braking force.

Returning to fig. 3, step S106 is a step of determining whether or not a slip of the drive wheels 11 is detected, as in step 101. In step S106, it is determined whether or not the slip of the drive wheels 11 is eliminated after the energization control mode of the generator 12 is set to the short-circuit braking mode in step S105.

When it is determined in step S106 that the slip of the drive wheels 11 is detected, the process proceeds to step S107, otherwise, the process skips step S107 and proceeds to step S108. That is, even if the energization control mode of the generator 12 is set to the short-circuit braking mode, the slip of the drive wheels 11 is not eliminated, and in this case, the ignition retard control is executed in step S107 again.

Step S107 is an engine output suppression step of executing the ignition delay control based on the ignition timing delay amount determined in advance in step S102. This step S107 is executed by the ignition control section 45. According to step S107, the ignition timing of the ignition plug 20 is delayed from the normal timing based on the ignition timing retardation amount, so that the output of the engine 10 is suppressed and the torque of the drive wheels 11 can be reduced.

Step S108 is a step of determining whether or not a predetermined crank angle has elapsed after the short-circuit brake mode is set in step S105. The rotation speed/crank angle position calculation unit 41 executes this step S108. If it is determined in step S108 that the predetermined crank angle has passed after the short-circuit brake mode is set, the process proceeds to step S109, and the short-circuit brake mode of the generator 12 is set to be released, and if not, the process returns to step S101. Therefore, according to this step S108, the purpose of setting the duration of the short-circuit braking mode of the generator 12 can be achieved.

In order to achieve this object, in step S108, the elapsed time may be measured instead of the crank angle and used as a parameter for determination. That is, this step S108 may be replaced with a step of determining whether or not the elapsed time from the setting of the short brake mode is longer than a predetermined time.

Next, the operation and effects of the engine control device 1 and the engine control method according to embodiment 1 will be described.

According to embodiment 1 described above, when a slip of the drive wheels 11 is detected, the energization control mode of the generator 12 can be set to the short-circuit braking mode in which the output terminals 12a are short-circuited to generate a braking force. At this time, the output terminals 12a of the generator 12 are short-circuited by turning off all of the three positive-side upper arm semiconductor elements SW1, SW2, and SW3 and turning on all of the three negative-side lower arm semiconductor elements SW4, SW5, and SW6 in the inverter circuit 18 of the generator 12. This can reduce the torque that increases the load on the crankshaft 13 when the drive wheels 11 slip.

In this case, unlike the control of the ignition delay control of the engine 10, which is performed with limited timing depending on the stroke of the engine 10, the control of the generator 12 is asynchronous without depending on the stroke of the engine 10, and can be set independently of the stroke of the engine 10.

Therefore, by setting the energization control mode of the generator 12 to the short-circuit braking mode, it is possible to execute a control of reducing the torque at the time of occurrence of a slip of the drive wheels 11 without a time delay compared to the ignition delay control of the engine 10, that is, a so-called "TRC control".

As a result, the responsiveness of the control for reducing the torque when the slip occurs in the drive wheels 11 can be improved.

Further, according to embodiment 1 described above, since the slip of the drive wheels 11 can be coped with by controlling the generator 12, it is not necessary to use an expensive brake system for performing brake control.

Further, according to embodiment 1 described above, when the slip of the drive wheels 11 is detected, the energization control mode of the generator 12 is set to the short-circuit braking mode when the predetermined setting start condition (see step S103 and step S104 in fig. 3) is established, so that the generator 12 can be set to the short-circuit braking mode at an appropriate timing.

Further, according to embodiment 1 described above, since the ignition delay control of the engine 10 is executed after the generator 12 is set to the short-circuit braking mode, the effect of reducing the torque of the drive wheels 11 can be improved as compared with the case where only the generator 12 is executed, and an increase in the amount of slip of the drive wheels 11 can be suppressed. In particular, the ignition delay control of the engine 10 can be executed at a necessary timing when the slip of the drive wheels 11 is not eliminated even if the energization control mode of the generator 12 is set to the short-circuit braking mode.

In embodiment 1 described above, the engine 10 is a single-cylinder engine, and a time lag may occur in reducing the torque compared to a multi-cylinder engine only by the output suppression by the ignition delay control of the engine 10. For example, in the case of a 4-cylinder engine, a delay time corresponding to a crank angle of 180 ° occurs at the maximum, whereas in the case of a single-cylinder engine, a delay time corresponding to a crank angle of 720 °, that is, a delay time of 4 times in the case of a 4-cylinder engine, may occur at the maximum. Therefore, by applying the control of the generator 12 as in embodiment 1 to the single cylinder engine, the effect of reducing the torque without causing a time delay when the drive wheels 11 slip can be expected.

Further, according to embodiment 1, since the generator 12 is directly coupled to the crankshaft 13, when the energization control mode of the generator 12 is set to the short-circuit braking mode, the load on the engine 10 can be applied to the maximum extent, and the maximum effect for reducing the torque can be obtained when the drive wheels 11 slip.

As a modification related to embodiment 1, the control of the generator 12 as in embodiment 1 may be applied to an engine that does not perform work at equal intervals. Since the unequal interval power engine applies power at unequal intervals, the interval until the next ignition is long or short. Thus, only by the output suppression by the ignition delay control, a difference is liable to occur in the timing to the execution start thereof. Therefore, by applying the control of the generator 12, which does not depend on the stroke of the engine 10, as in embodiment 1, to the engine working at unequal intervals, an effect of eliminating the occurrence of such a difference in timing can be expected.

Hereinafter, another embodiment related to embodiment 1 will be described with reference to the drawings. In other embodiments, the same elements as those in embodiment 1 are assigned the same reference numerals, and descriptions of the same elements are omitted.

(embodiment mode 2)

The engine control device of embodiment 2 has the same elements as those of the engine control device 1 of embodiment 1. On the other hand, the slip suppression control according to embodiment 2 is different from the embodiment in that the fuel cut control is executed instead of the ignition delay control and executed in accordance with the flowchart shown in fig. 8.

Except for this, the same procedure as in embodiment 1 is applied.

Steps S201, S203 to S206, S208, and S209 in fig. 8 are the same as steps S101, S103 to S106, S108, and S109 in fig. 3, and the description thereof will be omitted.

Step S202 is a control parameter determination step of determining the fuel cut amount according to the slip state of the drive wheels 11. The ignition timing retardation amount is a control parameter when executing the engine output suppression control, i.e., the fuel cut control, in synchronization with the stroke of the engine 10. This step S202 is executed by the TRC control amount determination unit 44.

Step S207 is an engine output suppressing step of executing fuel cut control based on the fuel cut amount determined in advance in step S202. This step S207 is executed by the injection control portion 46. According to step S207, the fuel injection amount from the injector 32 is reduced from the normal state based on the fuel cut amount, whereby the output of the engine 10 can be suppressed and the torque of the drive wheels 11 can be reduced.

According to embodiment 2 described above, since the fuel cut control of the engine 10 is executed after the energization control mode of the generator 12 is set to the short-circuit braking mode, the effect of reducing the torque of the drive wheels 11 can be improved and an increase in the amount of slip of the drive wheels 11 can be suppressed, as compared with the case where only the control of the generator 12 is executed. In particular, the fuel cut control of the engine 10 can be executed at a necessary timing when the slip of the drive wheels 11 is not eliminated even if the energization control mode of the generator 12 is set to the short-circuit braking mode.

Otherwise, the same operational effects as those of embodiment 1 are obtained.

As a modification example related to embodiments 1 and 2, both of the ignition delay control and the fuel cut control may be executed.

The present invention is described based on embodiments, but it should be understood that the present invention is not limited to the embodiments and the configurations. The present invention also includes various modifications and modifications within the equivalent scope. In addition, various combinations or forms, and further, other combinations or forms including only one element, more elements or less elements among them are also included in the scope or the idea of the present invention.

In the above-described embodiment, the energization control mode of the generator 12 is set to the short-circuit braking mode when the predetermined setting start condition is satisfied when the detection of the drive wheels 11 is detected, but instead, the step of determining the satisfaction of the predetermined setting start condition may be omitted, and the energization control mode of the generator 12 may be unconditionally set to the short-circuit braking mode when the slip of the drive wheels 11 is detected.

In the above-described embodiment, the case where the ignition delay control or the fuel cut control of the engine 10 is executed when the slip of the drive wheels 11 is detected after the energization control mode of the generator 12 is set to the short-circuit braking mode has been described as an example, but instead, the step of detecting the slip of the drive wheels 11 may be omitted after the energization control mode of the generator 12 is set to the short-circuit braking mode.

In the above-described embodiment, the case where all the upper arm semiconductor elements are turned off and all the lower arm semiconductor elements are turned on when the energization control mode of the generator 12 is set to the short-circuit braking mode has been described, but instead, the short-circuit braking mode may be implemented by pulse control by PWM driving, and the load applied to the engine 10 may be gradually changed or the load applied to the engine 10 may be changed in accordance with the slip ratio.

In the above-described embodiment, the case where the control for setting the energization control mode of the generator 12 to the short-circuit braking mode is applied to the engine 10, which is a single-cylinder engine, has been described as an example, but it is needless to say that this control may be applied to a multi-cylinder engine.

Claims (10)

1. An engine control device (1) is provided with:

an engine (10) that drives a drive wheel (11);

a three-phase starter generator (12) connected to a crankshaft (13) of the engine; and

a control unit (40) that controls the engine and the three-phase starter generator;

the control unit is configured to set an energization control mode of the three-phase starter generator to a short-circuit braking mode in which a braking force is generated by short-circuiting output terminals (12a) of the three-phase starter generator when a slip of the drive wheel is detected,

the control unit is configured to set an energization control mode of the three-phase starter generator to the short-circuit braking mode when a predetermined setting start condition is satisfied when the slip of the drive wheel is detected,

the control unit is configured to determine that the predetermined setting start condition is satisfied when the degree of progress of a stroke after ignition of the engine is small and a time until next ignition is long when the slip of the drive wheel is detected.

2. The engine control apparatus as set forth in claim 1,

the three-phase starter generator includes an inverter circuit (18), the inverter circuit (18) including three-phase upper arm semiconductor elements (SW1, SW2, SW3) on a positive electrode side and three-phase lower arm semiconductor elements (SW4, SW5, SW6) on a negative electrode side;

the control unit is configured to short-circuit the output terminals of the three-phase starter generator by turning off all of the upper arm semiconductor elements of the three phases and turning on all of the lower arm semiconductor elements of the three phases in the short-circuit braking mode of the three-phase starter generator.

3. The engine control apparatus as set forth in claim 1,

the control unit is configured to determine a control parameter for engine output suppression control synchronized with a stroke of the engine based on a slip state of the drive wheel when the slip of the drive wheel is detected, and execute the engine output suppression control based on the determined control parameter.

4. The engine control apparatus according to claim 3,

the control unit is configured to execute the engine output suppression control when the slip of the drive wheel is not eliminated after the energization control mode of the three-phase starter generator is set to the short-circuit braking mode.

5. The engine control device according to any one of claims 1 to 4,

the engine is a single cylinder engine with 1 cylinder number.

6. The engine control device according to any one of claims 1 to 4,

the engine is a non-equal interval work-doing engine with non-equal interval work-doing intervals.

7. An engine control method, comprising:

a slip detection step (S101) for detecting a slip of a drive wheel (11) driven by an engine (10);

a short-circuit braking mode setting step (S105) for setting, when a slip is detected in the slip detection step and if a predetermined setting start condition is satisfied, an energization control mode of a three-phase starter generator (12) connected to a crankshaft (13) of the engine to a short-circuit braking mode in which a braking force is generated by short-circuiting output terminals (12a) of the three-phase starter generator; and

and a determination step (S103, S104) for determining that the predetermined setting start condition is satisfied when the degree of progress of the stroke after ignition of the engine is small and the time until the next ignition is long when the slip of the drive wheel is detected.

8. The engine control method according to claim 7,

in the short-circuit braking mode setting step, the output terminals of the three-phase starter generator are short-circuited by turning off all the three-phase upper arm semiconductor elements (SW1, SW2, SW3) on the positive side and turning on all the three-phase lower arm semiconductor elements (SW4, SW5, SW6) on the negative side in the inverter circuit (18) of the three-phase starter generator.

9. The engine control method according to claim 7 or 8, having:

a control parameter determination step (S102) for determining, when the slip of the drive wheel is detected, a control parameter for engine output suppression control that is synchronized with the stroke of the engine, based on the state of the slip of the drive wheel; and

and an engine output suppression step (S107) of executing the engine output suppression control based on the control parameter determined in the control parameter determination step.

10. The engine control method according to claim 9,

and executing the engine output suppressing step if the slip of the drive wheel is not eliminated after the short-circuit braking mode setting step.

Images