JP2009005532A - Vehicle controller and control method of vehicle controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve drive performance accompanied by the on/off-operation of an eco-switch. <P>SOLUTION: A vehicle controller 10 is constituted of a driving device 20 including an engine 22 and a rotary electric machine 24, a power supply circuit 30 connected to the rotary electric machine 24, a control device 50, and the eco-switch 42. The control device 50 includes: a low fuel consumption instruction determination module 52 which determines the on/off-operation of the eco-switch 42; a boosting upper limit value lowering module 54 which, when the eco-switch 42 is turned on, reduces a boosting upper limit of a step-up converter which is a voltage transformer 36 of the power supply circuit 30 at a predetermined lowering rate from a usual upper limit value to a limited upper limit value; and a boosting upper limit reset module 56 which, when the eco-switch 42 is turned off, resets and increases the boosting upper limit value of the step-up converter which is the voltage transformer 36 of the power supply circuit 30 at a predetermined increase rate from the limited upper limit value up to the usual upper limit value. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle control device and a control method for the vehicle control device, and more particularly to a vehicle control device and a vehicle control device that perform control in accordance with a low fuel consumption travel instruction from a user in a vehicle having a rotating electrical machine. It relates to a control method.

  In recent years, so-called electric vehicles such as environmentally friendly electric vehicles, hybrid vehicles, and fuel cell vehicles have attracted attention. From the viewpoint of being environmentally friendly, it is preferable to save energy such as improvement in fuel consumption. In order to improve fuel efficiency, the vehicle's operability and the comfort of the living space may be sacrificed somewhat, such as by restricting the vehicle's power performance and air conditioning. It is preferable to perform it by a simple operation of the person. Therefore, a switch or the like for giving a low fuel consumption travel instruction to the vehicle control unit is provided. Such a switch is sometimes called an “eco-mode switch” or simply “eco-switch”.

  For example, in Patent Document 1, for an electric vehicle control device capable of switching between a normal mode and an economy mode, the torque command value on the drive side of the travel motor is set to 60% of the normal mode in the economy mode to reduce power consumption. In the economy mode, it is disclosed that when the actual acceleration / required acceleration is 80% or less, climbing torque addition is performed, and when it is 90% or more, climbing torque subtraction is performed.

  As a technique related to the present invention, in Patent Document 2, in a vehicle shift control device having a plurality of drive sources, the clutch is disconnected during a shift, and the driving force of the engine is cut off during that time, and a feeling of deceleration is felt. Therefore, it is stated that the driving force is compensated by the electric motor as the second driving source. When the compensation torque down amount is larger than a predetermined reference torque, the torque is insufficient in the normal sine wave control for the inverter, so switching to the rectangular wave control is disclosed. Here, it is stated that sine wave control has a modulation factor of 0.61, but low vibration and noise, and rectangular wave control has a modulation factor of 0.78 and can produce a high torque.

JP-A-10-248106 JP 2005-155862 A

  According to the above prior art, by using the eco switch, it is possible to suppress the torque command of the traveling motor, which is a rotating electrical machine, to reduce power consumption and to improve fuel efficiency.

  When turning on / off the eco switch, if the torque command is suddenly reduced or increased, the driver may feel uncomfortable. For example, when the torque command is suddenly reduced when the eco switch is turned on, the power consumption is reduced, but there may be a feeling that the torque is suddenly released and the brake is suddenly applied. On the other hand, when the eco switch is switched from on to off, the torque increases rapidly, which may give a feeling of popping out. As described above, the so-called drivability may be lowered as the eco switch is turned on / off.

  The objective of this invention is providing the control method for vehicles which can improve the drivability accompanying on-off of an eco switch, and the control method of a vehicle control device.

  A vehicle control apparatus according to the present invention includes a drive unit having a rotating electrical machine and a power supply device connected to the rotating electrical machine, an acquisition unit that acquires a low fuel consumption travel instruction from a user, and a control that controls the drive unit. And a control unit that determines whether or not a low fuel consumption travel instruction has been acquired, and when the low fuel consumption travel instruction has been acquired, sets the upper limit value of the torque limit to a predetermined normal upper limit. When there is a limit means for reducing the value at a predetermined voltage / time down rate to obtain a predetermined limit upper limit value, and when releasing the low fuel consumption travel instruction, the torque limit upper limit value is set to the predetermined limit upper limit value. And a return means for returning to a predetermined normal upper limit condition by increasing at a predetermined voltage / time up rate.

  In the vehicle control device according to the present invention, the down rate is preferably a value that prioritizes drivability over low fuel consumption performance.

  In the vehicle control device according to the present invention, it is preferable that the up-rate is a value in which power performance is prioritized over drivability.

  In the vehicle control device according to the present invention, the up rate is preferably a value exceeding the down rate.

  In the vehicle control device according to the present invention, the limiting means lowers the boost upper limit value of the boost converter of the power supply circuit from a predetermined normal upper limit value at a predetermined voltage / time down rate to a predetermined limit upper limit value. Preferably, the return means raises the boost upper limit value of the boost converter of the power supply circuit from a predetermined limit upper limit value at a predetermined voltage / time up rate to return to a predetermined normal upper limit condition.

  In the vehicle control device according to the present invention, it is preferable that the limiting means does not limit the torque when the vehicle is in a regenerative state.

  With the above configuration, the vehicle control device determines whether or not a low fuel consumption travel instruction is acquired from the user, and when there is acquisition of a low fuel consumption travel instruction, the upper limit value of the torque limit is determined from a predetermined normal upper limit value. Decrease at the voltage / time down rate to the predetermined limit upper limit value, and when there is a cancellation after obtaining the low fuel consumption travel instruction, the torque limit upper limit value is changed from the predetermined limit upper limit value to the predetermined voltage / time. At an up-rate to restore the predetermined normal upper limit condition. As described above, when the low fuel consumption travel instruction is acquired or canceled by the eco switch, the torque limit or the torque limit is not suddenly released, but the torque limit or the torque is gently reduced at a predetermined down rate or a predetermined up rate. Since the restriction is released, drivability is improved.

  Further, in the vehicle control apparatus, the down rate gives priority to drivability over low fuel consumption performance. When the eco switch is turned on to limit the torque, the vehicle is often shifted to stable driving or is in stable driving. According to the above configuration, the fuel efficiency is slightly sacrificed, but the user's satisfaction with drivability is improved.

  In the vehicle control device, the up-rate gives priority to the power performance over the drivability. The case where the torque limit is released by turning off the eco switch is, for example, when acceleration is desired. According to the above configuration, drivability is slightly sacrificed, but satisfaction with the power performance such as acceleration of the user is improved.

  In the vehicle control device, the up-rate is a value exceeding the down-rate. That is, when the torque is limited, the drivability can be improved more slowly and the drivability can be improved. When the torque limitation is released, the drivability can be restored in a short time to improve the power performance such as acceleration.

  Further, in the vehicle control device, as a torque limit, the boost upper limit value of the boost converter of the power supply circuit is limited at a predetermined down rate, and as the torque limit release, the boost upper limit value of the boost converter of the power supply circuit is returned to the predetermined limit. Do it up. Thus, drivability can be improved by controlling the power supply circuit.

  In the vehicle control device, the limiting means does not limit the torque when the vehicle is in a regenerative state. When torque is limited, recovery of regenerative energy during braking may be insufficient. According to the above configuration, drivability when the eco switch is turned on / off can be improved during driving while sufficiently collecting regenerative energy.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, a motor / generator mounted on a vehicle will be described as a rotating electrical machine, but it may simply have a function as a motor or may simply have a function as a generator. A plurality of rotating electrical machines may be installed in the vehicle. The power supply circuit is described as having a secondary battery, a voltage converter, and an inverter circuit. However, the power supply circuit may have other elements such as a low-voltage DC / DC converter. In the following, the limitation on the boost upper limit value of the boost converter of the power supply circuit will be described as the torque limiting means for the rotating electrical machine, but torque limiting means other than this may be used. For example, torque limitation may be performed by upper limit limitation of torque command value, rotation speed limitation, or the like. Note that the voltage values and the like described below are examples for explanation, and can be appropriately changed according to vehicle specifications and the like.

  FIG. 1 is a diagram illustrating a configuration of the vehicle control device 10. The vehicle control device 10 is a system that controls a vehicle on which an engine and a rotating electrical machine are mounted. In particular, the vehicle control device 10 here has a function of performing control when an eco switch is turned on and off.

  The vehicle control device 10 includes a drive device 20 including an engine 22 and a rotating electrical machine 24, a power supply circuit 30 connected to the rotating electrical machine 24, and a control unit 50. In addition, an eco switch 42 is connected to the control unit 50. When attention is paid to the rotating electrical machine 24, the rotating electrical machine 24 and the power supply circuit 30 may be collectively referred to as a rotating electrical machine drive unit.

  The engine 22 in the drive device 20 is an internal combustion engine, and has a function of driving the drive wheels of the vehicle and driving the rotating electrical machine 24 to generate electric power based on the output. The rotating electrical machine 24 is a motor / generator (M / G) mounted on a vehicle, and is a three-phase synchronous rotating electrical machine that functions as a motor when electric power is supplied and functions as a generator during braking.

  The power supply circuit 30 is a circuit connected to the rotating electrical machine 24 that is a motor / generator, and supplies power when the motor / generator functions as a drive motor, or when the motor / generator functions as a generator. Has a function of receiving regenerative power and charging the power storage device.

  The power supply circuit 30 includes a power storage device 32 that is a secondary battery, a smoothing capacitor 34 on the power storage device side, a voltage converter 36, a smoothing capacitor 38 on the boost side, and an inverter circuit 40.

  As the power storage device 32, for example, a lithium ion assembled battery or a nickel hydride assembled battery having a terminal voltage of about 200 V, a capacitor, or the like can be used.

  The voltage converter 36 is a circuit having a function of boosting the voltage on the power storage device 32 side to, for example, about 650 V using the energy storage action of the reactor, and is also called a boost converter. The voltage converter 36 has a bidirectional function, and when the electric power from the inverter circuit 40 side is supplied to the power storage device 32 side as charging power, the high voltage on the inverter circuit 40 side is lowered to a voltage suitable for the power storage device 32. Also have. In FIG. 1, the high voltage side output of the voltage converter 36 is indicated by a boosted voltage V.

  The inverter circuit 40 converts the high-voltage DC power into AC three-phase drive power and supplies it to the motor / generator connected to each, and conversely, converts the AC three-phase regenerative power from the motor / generator into high-voltage DC charge power. A circuit having a function of converting.

  The eco switch 42 is an operator that can be arbitrarily operated by the user. When the eco switch 42 is turned on, the eco switch 42 has a function of outputting a low fuel consumption instruction signal indicating that the user desires low fuel consumption traveling. That is, the eco switch 42 is a low fuel consumption travel instruction means. The eco switch 42 can be provided at an appropriate position in the driver's seat, for example. The state of the eco switch 42, that is, whether it is on or off, is transmitted to the control unit 50.

  The control unit 50 has a function of controlling the operation of the rotating electrical machine 24 mounted on the vehicle through the control of the power supply circuit 30, and particularly here, through the control of the power supply circuit 30 when the eco switch 42 is turned on and off. It has a function of performing control to appropriately harmonize vehicle drivability and low fuel consumption performance.

  The control unit 50 is actually composed of a CPU, and includes a storage device that stores a program and the like, and an interface circuit with the eco switch 42 as other elements of the CPU as necessary. If these elements are present, they are connected to each other via an internal bus. The control unit 50 can be configured by a computer or the like suitable for mounting on a vehicle. The function of the control part 50 can also be made into a part of function of another vehicle-mounted computer. For example, the function of the control unit 50 can be given to a hybrid ECU that controls the entire vehicle.

  The control unit 50 determines whether or not the eco switch 42 is on or off, that is, when the low fuel consumption travel instruction determination module 52 that determines whether or not the low fuel consumption travel instruction has been acquired, and the eco switch 42 that is the low fuel consumption travel instruction means. In addition, when the boost upper limit lowering module 54 for lowering the boost upper limit of the boost converter, which is the voltage converter 36 of the power supply circuit 30, from the normal upper limit to the limit upper limit at a predetermined down rate, and when the eco switch 42 is turned off. In addition, the boosting upper limit value returning module 56 is configured to return the boosting upper limit value of the boosting converter, which is the voltage converter 36 of the power supply circuit 30, from the limit upper limit value to the normal upper limit value at a predetermined up rate. Such a function can be realized by executing software, and specifically, can be realized by executing an eco-switch related control program of a vehicle control program. Some of these functions may be realized by hardware.

  The operation of the above configuration, particularly each function of the control unit 50, will be described in detail with reference to the flowchart of FIG. 2 and the time chart of FIG. In the following, description will be made using the reference numerals in FIG. FIG. 2 is a flowchart showing a processing procedure for control when the eco switch 42 is turned on and off, and each procedure shows each processing procedure in the eco switch related control program of the vehicle control program. FIG. 3 is a time chart showing the time change of the state of the eco switch 42 and the step-up voltage state of the voltage converter 36 of the power supply circuit 30 in common with the time axis in relation to the flowchart of FIG. .

  In FIG. 2, in the control of the vehicle having the eco switch 42, it is first determined whether or not the eco control is ON (S10). This step is executed by the function of the low fuel consumption travel instruction determination module 52 in the CPU 52 of the control unit 50. Specifically, it is determined whether the eco switch 42 that gives a low fuel consumption travel instruction by the user is on or off. When the eco switch 42 is on, it is determined that eco control is on. When the eco switch 42 is off, It is not determined that the eco control is ON.

  If it is determined that the eco control is ON, the boost upper limit value of the boost converter which is the voltage converter 36 of the power supply circuit 30 is reduced at a predetermined down rate (S12). In this case, the boost upper limit value is determined in advance from the viewpoint of fuel efficiency, from the normal upper limit value that is the boost upper limit value when the eco switch 42 is not turned on, and is set lower than the normal upper limit value. The boost upper limit value is limited by lowering the boost upper limit value to the limit upper limit value (S14). In the above example, since the voltage converter 36 boosts about 200V to about 650V, the upper limit is usually about 650V. The upper limit limit is about 500 V, for example, depending on the setting of low fuel consumption performance.

These states are shown in FIG. That is, when the eco switch 42 is switched from OFF to ON, the upper limit value of the boosted voltage is reduced from the normal upper limit value V ₁ to the limit upper limit value V ₂ . At this time, instead of reducing the normal upper limit value V ₁ to the upper limit limit value V ₂ at a stretch, a decrease from V ₁ to V ₂ is executed under a predetermined down rate. In the example of FIG. 3, the decrease from V ₁ to V ₂ is performed over time t _down . In this case, the down rate = − (V ₁ −V ₂ ) / t _down .

  The magnitude of this down rate is set from the viewpoint of giving priority to drivability over low fuel consumption performance. This is because when turning on the eco switch to limit the torque, the vehicle is often moving to stable driving or is in stable driving. Alternatively, there is a sudden braking feeling and drivability is reduced. Therefore, it is preferable to set this down rate from the viewpoint of drivability during stable running.

  When it is not determined that the eco control is ON, that is, when the eco switch 42 is turned on, a process of increasing the boost upper limit value of the boost converter, which is the voltage converter 36 of the power supply circuit 30, at a predetermined up rate is performed (S14). . In this case, the boost upper limit value is restored from the limit upper limit value, that is, the boost upper limit value when the eco switch 42 is turned on, to the normal upper limit value, and the restriction of the boost upper limit value is released (S14). In the above example, the boost upper limit value is returned from the limit upper limit value of about 500V to the normal upper limit value of about 650V.

These states are shown in FIG. That is, when the eco switch 42 is switched from on to off, the upper limit value of the boosted voltage is increased and returned from the limit upper limit value V ₂ to the normal upper limit value V ₁ . At this time, instead of increasing the limit upper limit value V ₂ to the normal upper limit value V ₁ at a stretch, an increase return from V ₂ to V ₁ is executed under a predetermined up-rate. In the example of FIG. 3, the increase from V ₂ to V ₁ is executed over time t _up . In this case, the up rate = + (V ₁ −V ₂ ) / t _up .

  The magnitude of this update rate gives priority to power performance over drivability. This is because, when turning off the eco switch and releasing the torque limit, for example, there are many cases where you want to accelerate, for example, if the up rate is too small with an emphasis on drivability, the acceleration will rise slowly and the acceleration will be felt This is because it may be felt insufficient. Therefore, it is preferable to set the up-rate from the viewpoint of power performance such as acceleration.

The up rate value is set to a value exceeding the down rate value. In the above example, t _up <t _down is set. As a result, when the torque is limited, the lowering of the boost upper limit value is slowly improved to further improve drivability, and when the torque limit is released, the boost upper limit value is returned in a short time to further improve the power performance such as acceleration. be able to.

  4 and 5 are diagrams showing a comparison between the related art and the above-described configuration. In the following, description will be made using the reference numerals in FIG. 4 and 5 are diagrams showing the state when the eco switch 42 is turned on / off on the torque-rotation speed characteristic diagram of the rotating electrical machine 24. The solid line indicates the eco switch 42 is off, and the broken line indicates the eco switch 42. When it is turned on.

  FIG. 4 is a diagram showing the case of the prior art, in which the torque-rotation speed characteristic changes suddenly when the eco switch 42 is turned on / off. If the rotational speed of the rotating electrical machine 24 is left as it is, the torque changes suddenly when the eco switch 42 is turned on and off. Therefore, when the eco switch 42 is turned on, the torque is suddenly reduced to give a sudden braking feeling, and when the eco switch 42 is turned off, the torque is suddenly raised to give a feeling of popping.

  FIG. 5 shows a case where predetermined down rates and up rates are provided for the decrease and increase of the boost upper limit value when the eco switch 42 is turned on and off, as described with reference to FIG. In this case, the torque-rotational speed characteristic changes over a predetermined time from when the eco switch 42 is turned on or off. If the rotational speed of the rotating electrical machine 24 is left as it is, the torque gradually changes from when the eco switch 42 is turned on or off. Therefore, even when the eco switch 42 is turned on, a sudden braking feeling due to a sudden decrease in torque is not generated, and even when the eco switch 42 is turned off, a feeling of jumping out due to a sudden increase in torque is not generated, and drivability is improved. .

  When the vehicle is in a regenerative state, it is preferable not to limit the boost upper limit value even if the eco switch is turned on. That is, if torque limitation is performed by limiting the boost upper limit value, recovery of regenerative energy during braking may be insufficient. Therefore, even if the eco switch is turned on during regeneration, if the torque is not limited, drivability when the eco switch is turned on / off during driving can be improved while sufficiently collecting regenerative energy.

It is a figure which shows the structure of the control apparatus for vehicles in embodiment which concerns on this invention. In embodiment which concerns on this invention, it is a flowchart which shows the procedure of the process about control when an eco switch is turned on / off. In embodiment which concerns on this invention, it is a time chart which shows each time change of the state of an eco switch, and the state of the step-up voltage of the voltage converter 36 of a power supply circuit. It is a figure which shows a mode when an eco switch is turned on / off in a prior art. It is a figure which shows a mode when an eco switch is turned on / off in embodiment which concerns on this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Vehicle control device, 20 Drive device, 22 Engine, 24 Rotating electrical machine, 30 Power supply circuit, 32 Power storage device, 34, 38 Smoothing capacitor, 36 Voltage converter, 40 Inverter circuit, 42 Eco switch, 50 Control unit, 52 Low Fuel consumption travel instruction determination module, 54 Boost pressure upper limit lowering module, 56 Boost pressure upper limit return module.

Claims (7)

A drive unit having a rotating electrical machine and a power supply device connected to the rotating electrical machine;
Acquisition means for acquiring a low fuel consumption driving instruction from a user;
A control unit for controlling the drive unit;
With
The control unit
Low fuel consumption travel instruction determination means for determining whether or not a low fuel consumption travel instruction has been acquired;
Limiting means for lowering the upper limit value of the torque limit from the predetermined normal upper limit value at a predetermined voltage / time down rate to obtain the predetermined upper limit limit when obtaining the low fuel consumption travel instruction;
A return means for raising the upper limit value of the torque limit from the predetermined limit upper limit value at a predetermined voltage / time up rate to return to the predetermined normal upper limit condition when there is a cancellation after the acquisition of the low fuel consumption travel instruction;
The vehicle control device characterized by including. The vehicle control device according to claim 1,
The down-rate is a value that gives priority to drivability over low fuel consumption performance. The vehicle control device according to claim 1,
The up-rate is a value that gives priority to power performance over drivability. The vehicle control device according to claim 1,
The up-rate is a value exceeding the down-rate. The vehicle control device according to claim 1,
The limiting means is
Decreasing the boost upper limit value of the boost converter of the power supply circuit from a predetermined normal upper limit value at a predetermined voltage / time down rate to a predetermined limit upper limit value,
The return means is
A vehicle control means for raising a boost upper limit value of a boost converter of a power supply circuit from a predetermined limit upper limit value at a predetermined voltage / time up rate to return to a predetermined normal upper limit condition. The vehicle control device according to claim 1,
The limiting means is
A vehicle control device characterized in that torque limitation is not performed when the vehicle is in a regenerative state.   A control method for a vehicle control device for controlling the vehicle control device according to claim 1.

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