JP2010023600A - Control device for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for a hybrid vehicle capable of realizing smooth start by operation with less burden with a simple and low cost structure. <P>SOLUTION: The control device 5 detects hill start (or start in a state where a load is comparatively large such as where vehicle weight is large) based on step-on information of an accelerator pedal 21, executes an easy hill start control mode when the hill start is detected, and switches a control target of operation control of a motor generator 2 from conventional load torque into a rotational speed of the motor generator 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for a HEV (Hybrid Electric Vehicle) including an internal combustion engine and an electric motor as drive sources, and more particularly to a control device for assisting starting.

For example, in Patent Document 1, in a hybrid vehicle including an internal combustion engine and an electric motor as drive sources, a required torque (target vehicle drive) determined based on a driver's request (for example, accelerator depression amount, internal combustion engine rotation speed, etc.). Torque: For example, when the road surface gradient detected by using an inclination sensor or the like is large, for example, the load ratio between the internal combustion engine and the motor with respect to the driver's accelerator pedal operation information, vehicle speed information, vehicle weight, etc.) (for example, A technique for assisting the start (acceleration) by increasing the load ratio of the electric motor (assist torque by the electric motor) is described in "Slope start". In the case of Cited Document 1, even when the vehicle weight detected by using a weight sensor or the like is heavy, similarly, the load ratio (assist torque by the motor) is increased to assist the start (acceleration). Like to do.
JP 7-245807 A

  However, the apparatus described in Patent Document 1 uses an inclination sensor (or a weight sensor) or the like in order to improve startability (or startability when the vehicle weight (loading weight) is large) when starting on a slope. Since the road surface gradient (or vehicle weight) is detected and the starting assistance is performed based on the detection result, it is necessary to separately provide a relatively expensive inclination sensor (or weight sensor), which complicates the configuration. At the same time, there is an actual situation in which the cost increases.

  Further, in Patent Document 1, even when starting on a slope (or starting when the vehicle weight is large), as with starting on a flat road (or starting when the vehicle weight is small), the driver's request (for example, accelerator) Since the required torque is calculated based on the amount of depression, the rotational speed of the internal combustion engine, etc., when starting on a slope (or when the vehicle is heavy), the driver cannot obtain the expected acceleration or In response to a decrease in the rotational speed of the engine 1, the driver needs to depress the accelerator pedal greatly, and there is a situation that the burden on the driver is greater than when starting on a flat road.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a control device for a hybrid vehicle that can realize a smooth start by an operation with less burden while having a simple and inexpensive configuration. In particular, a hybrid that can smoothly start a vehicle with operability equivalent to that of a relatively lightly loaded start on a flat road or the like even when starting a relatively heavy load such as when starting on a hill or when the vehicle weight is heavy. An object of the present invention is to provide a vehicle control device.

For this reason, the control device for a hybrid vehicle according to the present invention provides:
A control device for a hybrid vehicle comprising an internal combustion engine and an electric motor as drive sources,
When starting, information related to the rotation speed is used as a control target value in the operation control of the electric motor.

When the present invention has a function of controlling the operation of the internal combustion engine and the electric motor according to the burden ratio of the internal combustion engine and the electric motor with respect to the target vehicle driving torque set according to the request of the driver,
At the time of starting, the operation of the internal combustion engine is controlled with the burden ratio of the internal combustion engine with respect to the target vehicle driving torque as a control target value, and information related to the rotational speed is used as the control target value for the operation control of the motor. Can be a feature.

  In the present invention, the operation control of the electric motor may include a feedback control function that reduces a deviation between a control target value and information related to the actually detected rotational speed.

  In the present invention, the start may be a start in a relatively heavy load state.

  In this invention, the said start can be detected based on a driver | operator's accelerator pedal operation information in the predetermined time from a vehicle stop state, It can be characterized by the above-mentioned.

  According to the present invention, it is possible to provide a control device for a hybrid vehicle that can realize a smooth start by an operation with less burden while having a simple and inexpensive configuration. In particular, a hybrid vehicle capable of smoothly starting the vehicle with operability equivalent to starting with a relatively small load on a flat road or the like even when starting on a slope or when the vehicle is heavy. A control device can be provided.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the accompanying drawings. The present invention is not limited to the embodiments described below.

  As shown in FIG. 1, a hybrid vehicle (HEV: Hybrid Electric Vehicle) according to an embodiment of the present invention includes an internal combustion engine 1, a motor generator 2 rotationally connected to the internal combustion engine 1, and a battery 3. And the inverter circuit 4 provided between this battery 3 and this motor generator 2 is mounted.

  The motor generator 2 is constituted by a squirrel-cage induction machine. When the motor generator 2 is driven by supplying a three-phase alternating current that gives a rotating magnetic field having a rotational speed larger than the rotational speed (rotational speed) of the rotary shaft to the field winding, When a three-phase alternating current is applied to the field winding to provide a rotating magnetic field having a rotational speed smaller than the rotational speed of the rotating shaft, the mechanical energy applied to the rotating shaft is converted into electrical energy, which is It is comprised so that it can take out from a field winding as a phase alternating current.

The AC current supplied to the motor generator 2 in order to cause the motor generator 2 to function as a vehicle drive source is obtained by converting the DC current supplied from the battery 3 by the inverter circuit 4.
Further, the three-phase alternating current generated when the motor generator 2 is operated as a generator is converted into a direct current by the inverter circuit 4 and regenerated by charging the battery 3.

  The frequency on the AC side of the inverter circuit 4 (that is, the rotational speed of the rotating magnetic field of the motor generator 2) takes in the output of the rotation sensor 6 that detects the rotational speed of the rotating shaft of the internal combustion engine 1, that is, the motor generator 2. The control circuit 5 that controls the inverter circuit 4 is controlled based on the fetched output.

  That is, when the motor generator 2 is operated as an electric motor and auxiliary acceleration (assist) is performed, the control circuit 5 takes in the output of the accelerator sensor 17 that is linked to the operation of the accelerator pedal 21 and requests the driver to request. Torque (target vehicle drive torque: determined based on, for example, operation information of the accelerator pedal 21 of the driver, vehicle speed information, vehicle weight, etc.), a load ratio (load torque) of the internal combustion engine 1 with respect to the required torque, and motor generation The load ratio (load torque) of the machine 2 is acquired with reference to, for example, a map determined based on the vehicle running state (vehicle speed, gear position, etc.), and the load ratio (load torque) of the internal combustion engine 1 is obtained. A control command is sent to the engine control circuit that controls the operation of the internal combustion engine 1 so as to achieve the inverter, and the inverter is configured to achieve the load ratio (load torque) of the motor generator 2. And controls the motor circuit 4. During such auxiliary acceleration, energy is supplied from the battery 3 to the motor generator 2.

  When electric braking (regenerative braking) is performed by operating the motor generator 2 as a generator, the control circuit 5 is a rotating magnetic field that is slightly smaller (negative, that is, a rate of 0 to several percent) than the rotation speed detected by the rotation sensor 6. Is generated in the field winding of the motor generator 2. At this time, energy is supplied from the motor generator 2 to the battery 3 or is consumed by the resistor 11 via the semiconductor switch circuit 12.

  At this time, the terminal voltage of the battery 3 is observed by the detection circuit 13. If the battery 3 has a margin for charging, the switch control circuit 14 sets the semiconductor switch circuit 12 in a non-conducting state, and the current charges the battery 3. Flowing into.

  On the other hand, when the battery 3 is charged to a predetermined level and does not need to be charged, the switch control circuit 14 sets the semiconductor switch circuit 12 in a conductive state, and the electric energy generated by the regenerative braking of the motor generator 2 is a resistor. 11 is consumed.

  The vehicle speed sensor 16 is a sensor for detecting a vehicle speed by detecting, for example, wheel rotation or rotation on the output side of the transmission. The ratio of the rotational speed to the rotational speed on the output side) can be used to know which gear position the transmission is currently in. The transmission may be either an automatic transmission or a manual transmission. In the case of a continuously variable transmission, the gear ratio can be used as it is in the control described below without knowing the gear position.

  The standard terminal voltage of the battery 3 is, for example, 300V, which is converted to 24V by the DC / DC converter 19 for use in the electric equipment of the vehicle.

  Here, in the hybrid vehicle having the above-described configuration, conventionally, when starting the vehicle, the driver requests from the output of the accelerator sensor 17 in the same manner as the control in the normal traveling after reaching the predetermined vehicle speed. The required torque is obtained, the burden ratio (burden torque) of the internal combustion engine 1 with respect to the required torque and the burden ratio (load torque) of the motor generator 2 are acquired by referring to, for example, a map, and the acquired burden of the internal combustion engine 1 The operation of the internal combustion engine 1 is controlled so as to achieve the ratio (burden torque), and the control is performed so as to achieve the acquired burden ratio (burden torque) of the motor generator 2. When starting (or starting when the vehicle weight is heavy), the driver is not able to obtain the expected acceleration, or against the drop in the rotational speed (number of rotations) of the internal combustion engine 1. To must dig increase the accelerator pedal 21 was greater burden to the driver in comparison with the starting or the like on a flat road.

  For this reason, the control device 5 according to the present embodiment detects a start on a slope or a start with a relatively heavy load such as when the vehicle weight is large by a simple method. The start control mode is executed, and the control target of the operation control of the motor generator 2 is switched from the conventional burden torque to the rotational speed of the motor generator 2.

Specifically, as shown in the flowchart of FIG.
In S (step, hereinafter the same) 1, it is determined whether or not an easy slope start control mode start condition is satisfied.
For example, when the vehicle is in a stopped state (the vehicle speed is below a predetermined value), and in a power line contact state (gear-in (a state where the input shaft and output shaft of the transmission are rotationally connected via a gear) and a clutch contact state (a clutch is connected) In a state where the output shaft of the internal combustion engine 1 (motor generator 2) and the input shaft of the transmission 2 are connected), the depression amount (accelerator opening) of the accelerator pedal 21 is as shown in FIG. As shown in the time chart, a relatively heavy load such as when starting on a hill (or when the vehicle weight is large) when the direction of the accelerator pedal 21 changes within a predetermined determination time in a predetermined (determined) time (increase). The start of the easy slope start control mode is determined to be satisfied.

If YES, the process proceeds to S2.
On the other hand, if NO, the process proceeds to S6, the easy slope start control mode flag is set to 0 (False), and then normal operation control (requested torque = internal combustion) according to the driver's request (accelerator operation) in S7. The torque of the engine 1 + the torque of the motor generator 2) is executed, and this flow ends.

Note that when starting with a relatively light load, such as when the road is flat or the vehicle weight (loading weight) is small, it is erroneously determined that the vehicle is starting on a slope and the driver is shifted to the easy slope start control mode. As shown in the time chart of FIG. 4, the accelerator pedal is once turned off without satisfying the above-mentioned easy slope start control mode start condition, in order to avoid such fear. When the accelerator pedal 21 is further depressed after stepping on the predetermined number 21 and the above-mentioned easy slope start control mode start condition is satisfied, the accelerator opening is not changed within the predetermined determination time. As described above, it is not determined that the vehicle starts on a slope, and the shift to the above-described easy slope start control mode is not performed.
Therefore, in such a case, a NO determination is made in S1, and normal operation control according to the driver's request (accelerator pedal operation) is performed in S7.

In S2, it is determined whether or not the easy slope start control mode end condition determination exclusion time has elapsed. That is, after the easy slope start control mode condition is established, the easy slope start control mode should be maintained for a predetermined time (for example, until the vehicle starts and reaches a predetermined vehicle speed (see conditions (1) to (4) below)). Thus, it is determined not to determine whether the easy slope start control mode end condition is satisfied.
However, even before the exclusion time has elapsed, when the foot is released from the accelerator pedal 21 or the brake pedal 22 is depressed, the easy slope start control mode condition is canceled and the driver's request is issued. You can also give priority.
If YES, the process proceeds to S3 because the exclusion time has elapsed, and if NO, the process proceeds to S4 because the exclusion time has not elapsed.

In S3, it is determined whether or not an easy slope start control mode end condition is satisfied. For example, the condition for ending the easy slope start control mode may be satisfied when any of the following conditions is satisfied.
(1) The amount of depression of the accelerator pedal 21 has been returned by a predetermined amount or more (2) The vehicle speed has become equal to or greater than the predetermined vehicle speed (3) The clutch pedal has been depressed by a predetermined amount (4) Driver's required torque ≧ Slope start torque ( (Starting torque adapted to a predetermined slope starting)

If YES, the process proceeds to S6 in order to end the start assist control in the easy slope start control mode, the easy slope start control mode flag is set to 0 (False), and then the driver request (accelerator pedal) in S7. The normal operation control according to the operation) (required torque = the burden torque of the internal combustion engine 1 + the burden torque of the motor generator 2) is executed, and this flow is finished.
On the other hand, if NO, the process proceeds to S4.

  In S4, the easy slope start control mode flag is set to 1 (True). In S5, the start assist control in the easy slope start control mode is executed, and this flow ends.

  Note that, in the start assist control in the easy slope start control mode performed in S5, the control device 5 takes in the output of the accelerator sensor 17 linked to the operation of the accelerator pedal 21, and obtains the required torque requested by the driver. The load ratio (load torque) of the internal combustion engine 1 with respect to the required torque is acquired with reference to, for example, a map or the like determined based on the vehicle running state (vehicle speed, gear position, etc.). In the present embodiment, as shown in the time chart of FIG. 5, the operation of the internal combustion engine 1 is performed so that the required torque is achieved by the generated torque of the internal combustion engine 1, for example, with the burden ratio of the internal combustion engine 1 being 100%. Although it is controlled, the present invention is not limited to this, and it is possible to appropriately change the burden ratio of the internal combustion engine 1 that is operating in the easy slope start control mode in accordance with required start characteristics and the like.

  The control device 5 sends a control command to the engine control circuit so as to achieve the burden ratio (here, 100%) of the internal combustion engine 1 acquired as described above. A target rotational speed adapted to the start is given as a control target value, and the drive of the motor generator 2 is controlled via the inverter circuit 4 so as to achieve the target rotational speed (for example, PWM (Pulse Width Modulation) control) Execute speed control by). The control target value is not limited to the target rotation speed, but can be information related to the target rotation speed such as the vehicle speed.

  The control with the target rotational speed as the control target is so-called feedback control in which the actual rotational speed is acquired from the detection signal of the rotation sensor 6 and the deviation between the actual rotational speed and the target rotational speed is reduced. Can do.

  Note that such feedback control can be PID control that provides proportional (P), integral (I), and differential (D) feedback correction amounts. However, not only PID control but also a configuration in which at least one of P, I, and D is given as a feedback correction amount according to a request for control accuracy and the like.

  Furthermore, in the start assist control by the easy slope start control mode, a so-called feedforward control in which a control amount that will achieve the target rotation speed is obtained in advance through experiments or the like and is given in advance as a control amount; Feedback control can be combined, and in such a case, both responsiveness and control accuracy can be achieved.

  In addition, according to requests such as control accuracy and responsiveness, the start assist control in the easy slope start control mode can be configured only by the feedforward control.

  As described above, in this embodiment, when starting on a slope (or starting with a relatively heavy load such as when the vehicle weight is large), the internal combustion engine 1 and the motor generator 2 with respect to the torque required by the driver are used. Since information related to the rotational speed is used as the control target value for the drive control of the motor generator 2 from the conventional control in which the burden torque is the control target value (see the time chart of FIG. 6), the time of FIG. As shown in the chart, as compared with the conventional control, even if the driver does not depress the accelerator pedal 21 greatly, the rotational speed of the internal combustion engine 1 does not decrease and the rotational speed (and hence the vehicle speed) increases smoothly. Therefore, a smooth start with less burden on the driver can be realized.

  In addition, according to the present embodiment, it is possible to detect a start with a relatively large load (starting on a hill or starting with a heavy load) by a simple method, so that it is relatively expensive as in the past. Since it is not necessary to provide an inclination (road surface gradient) sensor, a weight sensor, or the like, or to execute complicated estimation control for estimating the road surface gradient or the vehicle weight, it is possible to reduce costs. However, the easy slope start control according to the present embodiment is executed even when an inclination (road surface gradient) sensor, a weight sensor, or the like is provided, or when complicated estimation control for estimating the road surface gradient or the vehicle weight is executed. It is also possible.

  In this embodiment, the configuration is such that the transition to the easy slope start control mode is made at the start of a relatively heavy load, but the present invention is not limited to this, and the transition to the easy slope start control mode is made at the time of start. Thus, information relating to the rotational speed can be used as the control target value for the drive control of the motor generator 2, and smooth start with less burden on the driver can be realized.

  By the way, the present invention is not limited to relatively large vehicles such as trucks and buses, but can also be applied to small vehicles such as ordinary passenger cars.

  The embodiment described above is merely an example for explaining the present invention, and various modifications can be made without departing from the gist of the present invention.

It is a figure showing roughly the whole composition concerning one embodiment of the present invention. It is a flowchart explaining the easy slope start control which the control apparatus which concerns on embodiment same as the above performs. It is a time chart explaining the slope start determination method which the control apparatus which concerns on embodiment same as the above performs. It is a time chart explaining the misjudgment prevention function in the slope start determination method which the control apparatus which concerns on embodiment same as the above performs. It is a time chart which showed the change of the rotational speed (rotation speed) or vehicle speed, each generated torque, and accelerator depression amount (opening) at the time of performing easy slope start control by the control apparatus which concerns on embodiment same as the above. It is the time chart which showed the change in the rotational speed (number of rotations) or vehicle speed, each generated torque, and accelerator depression amount (opening degree) at the time of performing the control in the case of the conventional slope start.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Motor generator 5 Control circuit 17 Acceleration sensor 21 Accelerator pedal

Claims (5)

A control device for a hybrid vehicle comprising an internal combustion engine and an electric motor as drive sources,
A hybrid vehicle control device using information related to a rotational speed as a control target value in operation control of an electric motor at the time of starting. When equipped with a function for controlling the operation of the internal combustion engine and the electric motor according to the burden ratio of the internal combustion engine and the electric motor with respect to the target vehicle driving torque set according to the driver's request,
At the time of starting, the operation of the internal combustion engine is controlled with the burden ratio of the internal combustion engine with respect to the target vehicle driving torque as a control target value, and information related to the rotational speed is used as the control target value for the operation control of the electric motor. The hybrid vehicle control device according to claim 1, wherein the control device is a hybrid vehicle control device.   The operation control of the electric motor has a feedback control function that reduces a deviation between a control target value and information related to an actually detected rotation speed. Control device for hybrid vehicle.   The control device for a hybrid vehicle according to any one of claims 1 to 3, wherein the start is a start in a relatively heavy load state. The hybrid vehicle control device according to any one of claims 1 to 4, wherein the start is detected based on information on an accelerator pedal operation performed by a driver within a predetermined time from a vehicle stop state. .

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