JP2005098251A - Control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To turn on a relay provided between a motor and a high voltage battery during travel of a vehicle. <P>SOLUTION: When an engine 1 is stared based on an operator's ignition key operation before the relay 5 is turned on, rotation speed of the engine 1 is controlled to a predetermined rotation speed and the relay 5 is turned on under a condition where rotation speed of the engine 1 is controlled at the predetermined rotation speed. Consequently, the main relay 5 can be turned on without damage even during travel of the vehicle. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle control device that turns on a high-power relay provided between a motor used as a travel drive source and a high-power battery after the engine is started.

  In a hybrid vehicle including an engine and a motor as a travel drive source, a system is known in which electric power is supplied to the starter motor to drive the starter motor and start the engine based on a driver's ignition key operation (patent) Reference 1).

JP 2000-257539 A

  However, in the conventional system, before turning on the high-voltage relay provided between the motor as the driving source and the high-power battery, the engine is started based on the driver's ignition key operation, and the vehicle is There is a case to start running. In this case, since the motor is driven by the engine and driven, the high-power relay cannot be turned on during traveling, and the power generation control of the motor cannot be performed. Therefore, there has been a problem that the SOC of the battery is lowered.

  When the engine is started before the relay is turned on, the vehicle control device according to the present invention controls the rotational speed of the engine to a predetermined rotational speed, and the engine rotational speed is controlled to the predetermined rotational speed. The relay is turned on.

  According to the vehicle control device of the present invention, since the relay can be turned on even after the engine is started, the electric power generated by the motor generator during vehicle travel is supplied to the battery, and the SOC of the battery is reduced. Can be prevented.

  FIG. 1 is a diagram showing a configuration of an embodiment in which a vehicle control device according to the present invention is applied to a hybrid vehicle. This hybrid vehicle includes an engine 1 and a motor generator 2 (hereinafter simply referred to as a motor 2) as a driving source for the vehicle. That is, the driving force of both or one of the engine 1 and the motor 2 is transmitted to the drive wheels 21a and 21b via the continuously variable transmission (CVT) 19 and the speed reducer 20.

  Generally, an electric motor (motor) is a power running operation by converting electric power into driving force, but can be regenerated by reversely converting driving force into electric power with the same structure. In addition, the generator (generator) converts the driving force into electric power for power generation operation (equivalent to regenerative operation), but it can be converted to electric power for driving operation with the same structure. It is. That is, the electric motor (motor) and the generator (generator) basically have the same structure, and both can be driven (power running) and generated (regenerated). Therefore, in this specification, a rotating electrical machine having both the function of an electric motor (motor) that converts electrical energy (electric power) into rotational energy (driving force) and the function of a generator (generator) that converts rotational energy into electrical energy. Is called a motor generator or simply a motor. On the other hand, an internal combustion engine converts combustion energy generated when fuel such as a gasoline engine or a diesel engine is burned into rotational energy (driving force). In this specification, these internal combustion engines are collectively referred to as engines.

  The engine 1 and the motor 2 are connected via a crank pulley clutch 14 and a pulley & belt power transmission mechanism 13. On / off of the crank pulley clutch 14 is controlled by a vehicle controller 9 described later.

  The main relay (high-power relay) 5 is provided between the inverter 3 and the 36V battery (high-power battery) 6, and ON / OFF control is performed by a vehicle controller 9 described later. The inverter 3 converts the DC power stored in the 36V battery 6 into three-phase AC power and supplies it to the motor (three-phase AC motor) 2 to drive the motor 2 (power running). Three-phase AC power generated by regenerative (power generation) operation is converted to DC power, and the 36V battery 6 is charged. The generated power converted into DC power by the inverter 3 is stepped down by the DC / DC converter 4 and used for charging the 12V battery 7.

  The rotational speed sensor 1 a detects the rotational speed of the engine 1 and transmits it to the vehicle controller 9. The vehicle speed sensor 18 detects the speed of the vehicle and transmits it to the vehicle controller 9.

  The vehicle controller 9 controls the engine controller 10, the motor controller 11, and the battery controller 12 to control the traveling of the vehicle, and performs idle stop control and restart control of the engine 1. The vehicle controller 9 exchanges information with the engine controller 10, the motor controller 11, and the battery controller 12 via the in-vehicle communication line 15.

  The engine controller 10 controls a throttle valve opening / closing device, a fuel injection device, and an ignition timing control device (not shown) so that the engine torque matches the torque command value input from the vehicle controller 9. The motor controller 11 controls the operation mode of the motor 2, that is, switching between the power running mode, the regenerative braking mode, and the power generation mode, and the rotational speed and output torque of the motor 2.

  The battery controller 12 detects the SOC (State Of Charge) of the 36V battery 6 based on the voltage and charge / discharge current of the 36V battery 6 detected by a voltage sensor and a current sensor (not shown), and charges the 36V battery 6. And manage the discharge.

  The vehicle controller 9, the engine controller 10, the motor controller 11, and the battery controller 12 are each composed of a microcomputer, a memory, an interface, and the like.

  The vehicle controller 9 performs an idle stop that automatically stops the engine 1 when a predetermined idle stop condition is satisfied. The idle stop condition is, for example, when the vehicle speed is equal to or lower than a predetermined vehicle speed, the accelerator pedal operation amount is 0, the brake pedal is turned on, and all conditions where the SOC of the 36V battery 6 is equal to or higher than a predetermined value are satisfied. Further, when the idle stop condition is no longer satisfied from the state where the idle stop condition is satisfied and the idle stop is performed, the idle stop is canceled and the engine 1 is restarted.

  The starter motor 8 is connected to the 12V battery 7 via the start switch 16. When the driver turns an ignition key (not shown) to the START position, the start switch 16 is turned on, and a current flows from the 12V battery 7 to the starter motor 8. As a result, the starter motor 8 is driven to start the engine 1.

  FIG. 2 is a diagram for explaining the control contents performed by the controllers 9 to 12 when the vehicle is started. When the driver turns an ignition key (not shown) to the ON position, the ignition switch 17 is turned on, and power is supplied from the 12V battery 7 to the vehicle controller 9. As a result, the vehicle controller 9 is activated. The activated vehicle controller 9 transmits an activation signal to the engine controller 10, the motor controller 11, and the battery controller 12 (i). Each controller 10, 11, 12 is activated upon receiving the activation signal.

  After the activation of the controllers 10 to 12, the vehicle controller 9 transmits a diagnosis request signal for the main relay 5 to the motor controller 11 (ii). The motor controller 11 that has received the diagnosis request signal performs a failure diagnosis of the main relay 5 and transmits a diagnosis result to the vehicle controller 9 (iii). The vehicle controller 9 turns on the main relay 5 when receiving a signal indicating that the main relay 5 is normal from the motor controller 11 and receiving a high power on permission signal from the battery controller 12 (iv). When the main relay 5 is turned on, a signal notifying that the main relay 5 is turned on is transmitted to the motor controller 11 (v).

  When receiving a signal notifying that the main relay 5 is turned on, the motor controller 11 checks whether or not charging of a capacitor (not shown) provided in the inverter 3 is completed. When it is determined that the charging is completed, a charging completion signal is transmitted to the vehicle controller 9 (vi). When the vehicle controller 9 receives the charge completion signal from the motor controller 11, the vehicle controller 9 transmits a strong power supply completion signal to the motor controller 11 (vii).

  When the vehicle controller 9 receives a control preparation completion signal from the engine controller 10, the motor controller 11, and the battery controller 12 (viii), the vehicle controller 9 turns on the crank pulley clutch 14 (ix), and complete explosion determination, that is, the engine 1 is started. (X). After the start of the engine 1 is completed, normal control is performed in the controllers 9 to 12.

  As described above, in the vehicle control device according to the embodiment, the start switch 16 is turned on based on the driver's ignition key operation, the starter motor 8 is driven, and the engine 1 is started. In other words, since the vehicle controller 9 does not intervene when starting the engine, the engine 1 is started and the vehicle starts running from the start of the vehicle controller 9 until the control for turning on the main relay 5 is completed. There is a case. In this case, since the failure diagnosis before turning on the main relay 5 is interrupted, it cannot be determined whether or not the main relay 5 can be turned on safely, and until the idle stop is performed, It remains blocked. During this time, since the 36V battery 6 cannot be charged, the SOC of the 36V battery 6 decreases.

  In the vehicle control device according to the embodiment, when the engine 1 is started and the vehicle starts running before the main relay 5 is turned on, control for turning on the main relay 5 is performed. Hereinafter, the control for turning on the main relay 5 after starting the vehicle travel will be described with reference to the flowchart shown in FIG.

  FIG. 3 is a flowchart showing the contents of control at the time of engine start performed by the vehicle control device according to the embodiment. The process starting from step S10 is performed by the vehicle controller 9. In step S10, it is determined whether or not the hybrid vehicle has started running before the main relay 5 is turned on.

  As described above, since the vehicle controller 9 turns on / off the main relay 5, the engine 1 is started by the starter motor 8 before the process of turning on the main relay 5 is completed after the vehicle controller 9 is started. Then, it is determined whether or not the vehicle has started running. Whether the vehicle has started traveling is determined based on a vehicle speed signal input from the vehicle speed sensor 18. If it is determined that the vehicle has started running before the main relay 5 is turned on, the process proceeds to step S20. On the other hand, when the vehicle starts traveling after the main relay 5 is turned on, or when the vehicle has not started traveling, the processing according to the flowchart is terminated.

  In step S20, control is performed so that the engine rotational speed N detected by the rotational speed sensor 1a matches a predetermined rotational speed Ns. The predetermined rotational speed Ns is calculated based on the motor rotational speed Nm that does not cause a failure of the high-power components including the main relay 5 even when the main relay 5 is turned on when the motor 2 is rotated by the engine 1. . The motor rotation speed Nm is obtained in advance by experiments or calculations using models. Here, if Nm = 1500 (rpm) and the pulley ratio between the engine 1 and the motor 2 of the pulley & belt power transmission mechanism 13 is 2.5, the predetermined rotational speed Ns of the engine 1 is Ns = 600 (= 1500 / 2.5) (rpm). That is, in step S20, control is performed to reduce the rotational speed N of the engine 1 that is higher than the predetermined rotational speed Ns (= 600) to the predetermined rotational speed Ns while the vehicle is traveling.

In step S30 following step S20, in order to keep the vehicle speed constant, the gear ratio of the continuously variable transmission 19 is calculated and changed to the calculated gear ratio. The vehicle speed is expressed by the following equation (1), and the final reduction ratio and the tire radius are values specific to the vehicle. The final reduction ratio is a ratio that is reduced by the reduction gear 20. Accordingly, since the gear ratio is expressed by equation (2), the gear ratio of the continuously variable transmission 19 is calculated based on the vehicle speed detected by the vehicle speed sensor 18 and the predetermined engine speed Ns.
Vehicle speed = engine rotation speed / transmission ratio / final reduction ratio × 2π × tire radius (1)
Gear ratio = engine speed / final reduction ratio / vehicle speed × 2π × tire radius (2)

  As described above, in step S20, control for lowering the rotational speed N of the engine 1 to a predetermined rotational speed Ns is performed. Therefore, in step S30, control for lowering the speed ratio of the continuously variable transmission 19 is performed.

  When the gear ratio of the continuously variable transmission 19 is calculated and changed to the calculated gear ratio, the process proceeds to step S40. In step S40, it is determined whether or not the rotational speed N of the engine 1 detected by the rotational speed sensor 1a matches a predetermined rotational speed Ns. If it is determined that the rotational speed N of the engine 1 does not match the predetermined rotational speed Ns, the process returns to step S20, and if it is determined that they match, the process proceeds to step S50.

  In step S50, before turning on the main relay 5, the upper limit value of the engine rotation speed is lower than a preset upper limit value so that the rotation speed of the motor 2, that is, the rotation speed N of the engine 1 does not increase. The value is changed to a predetermined upper limit value, and the process proceeds to step S60. In step S60, the main relay 5 is turned on and the process proceeds to step S70. In step S70, the upper limit value of the engine speed N changed in step S50 is returned to the upper limit value before the change, and the process according to the flowchart shown in FIG.

  According to the vehicle control device in the embodiment, before the main relay 5 provided between the 36V battery 6 and the inverter 3 is turned on, when the engine 1 is started and the vehicle starts running, Since the main relay 5 is turned on in a state where the rotational speed N is controlled to the predetermined rotational speed Ns, the main relay 5 can be turned on while the vehicle is traveling without being damaged. Thereby, the electric power generated by the regenerative operation of the motor 2 can be supplied to the 36V battery 6 and / or the 12V battery 7 while the vehicle is traveling, and the SOC of the batteries 6 and 7 can be prevented from decreasing. .

  Further, according to the vehicle control apparatus in the embodiment, the upper limit of the rotational speed N of the engine 1 is set before the main relay 5 is turned on in a state where the rotational speed N of the engine 1 is controlled to the predetermined rotational speed Ns. Since the value is set to a predetermined upper limit value, it is possible to prevent the rotational speed of the engine 1 from increasing when the main relay 5 is turned on. Thereby, it is possible to prevent the main relay 5 from being damaged when the main relay 5 is turned on when the rotational speed of the engine 1, that is, the rotational speed of the motor 2 is increased when the vehicle travels. Further, after the main relay 5 is turned on, the changed upper limit value of the rotational speed of the engine 1 is returned to the upper limit value before the change, so that the vehicle travel is not hindered.

  According to the vehicle control device in the embodiment, when the main relay 5 is turned on after the engine is started, the speed ratio of the continuously variable transmission 19 is determined based on the vehicle speed detected by the vehicle speed sensor 18 and the predetermined speed of the engine 1. Since the gear ratio is calculated based on the rotational speed Ns, the vehicle speed can be prevented from changing when the main relay 5 is turned on. Therefore, even if the main relay 5 is turned on while the vehicle is running, the driver does not feel uncomfortable.

  The present invention is not limited to the embodiment described above. For example, although the case where the continuously variable transmission 19 is used as the transmission has been described, the present invention is applied to a vehicle having a plurality of shift stages and equipped with an automatic transmission (automatic transmission) in which the gear ratio is changed discontinuously. You can also. In this case, it is only necessary to change to a gear stage having a gear ratio closest to the gear ratio calculated based on the above-described equation (2).

  In the flowchart shown in FIG. 3, in step S10, it is determined whether or not the hybrid vehicle has started running before the main relay 5 is turned on. However, before the main relay 5 is turned on, it is determined whether or not the engine 1 has been started, and if it is determined that the engine 1 has been started, the processing after step S20 may be performed. In step S10, the engine 1 may be started before the main relay 5 is turned on, and it may be determined whether or not the rotational speed N of the engine 1 is higher than a predetermined rotational speed Ns. That is, before the main relay 5 is turned on, when the engine 1 is started and the rotational speed N of the engine 1 becomes higher than the predetermined rotational speed Ns, the processing after step S20 may be performed.

  The correspondence between the constituent elements of the claims and the constituent elements of the embodiment is as follows. That is, the starter motor 8 is the engine starting means, the vehicle controller 9 and the engine controller 10 are the rotational speed control means, the vehicle controller 9 is the relay control means, the upper limit value setting means and the gear ratio changing means, and the vehicle speed sensor 18 is the vehicle speed detection. Each means is configured. In addition, unless the characteristic function of this invention is impaired, each component is not limited to the said structure.

The figure which shows the structure of one Embodiment which applied the vehicle control apparatus by this invention to the hybrid vehicle. The figure for demonstrating the control content performed by each controller at the time of vehicle starting The flowchart which shows the processing content performed by the vehicle control apparatus in one embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Engine 1a ... Speed sensor 2 ... Motor generator 3 ... Inverter 4 ... DC / DC converter 5 ... Main relay 6 ... 36V battery 7 ... 12V battery 8 ... Starter motor 9 ... Vehicle controller 10 ... Engine controller 11 ... Motor controller 12 ... battery controller 13 ... pulley & belt power transmission mechanism 14 ... crank pulley clutch 15 ... in-vehicle communication line 16 ... start switch 17 ... ignition switch 18 ... vehicle speed sensor 19 ... continuously variable transmission 20 ... speed reducers 21a, 21b ... drive wheels

Claims (6)

Engine starting means for starting the engine based on at least the driver's engine starting operation;
Rotational speed control means for controlling the rotational speed of the engine;
Controls the opening and closing of a relay provided between the motor generator driven by the engine and driving the engine and the battery that stores the electric power generated by the motor generator and supplies the electric power to the motor generator Relay control means for
The rotational speed control means controls the rotational speed of the engine to a predetermined rotational speed when the engine is started by the engine starting means before turning on the relay by the relay control means,
The vehicle control device, wherein the relay control means turns on the relay in a state where the rotational speed of the engine is controlled to the predetermined rotational speed. The vehicle control device according to claim 1,
Upper limit setting means for setting the upper limit value of the engine rotation speed to a predetermined upper limit value before the relay is turned on in a state where the engine rotation speed is controlled to the predetermined rotation speed by the relay control means. The vehicle control device further comprising: The vehicle control device according to claim 2,
The upper limit value setting means cancels the setting to the predetermined upper limit value when the relay is turned on by the relay control means. The vehicle control device according to any one of claims 1 to 3,
Vehicle speed detection means for detecting the speed of the vehicle;
A gear ratio changing means for changing the gear ratio of the continuously variable transmission in which the gear ratio changes continuously;
When the relay is turned on after the engine is started, the speed ratio changing means determines the speed ratio of the continuously variable transmission based on a vehicle speed detected by the vehicle speed detecting means and a predetermined rotational speed of the engine. A vehicular control device that changes to a calculated gear ratio. The vehicle control device according to any one of claims 1 to 3,
Vehicle speed detection means for detecting the speed of the vehicle;
Shift stage changing means for changing the shift stage of the automatic transmission having a plurality of shift stages and the gear ratio changing discontinuously;
When the relay stage is turned on after the engine is started, the gear stage changing unit is closest to a gear ratio calculated based on a vehicle speed detected by the vehicle speed detecting unit and a predetermined rotation speed of the engine. The vehicle control device is characterized in that the speed is changed to the gear position. In the vehicle control device according to any one of claims 1 to 5,
The vehicle control device, wherein the rotational speed control means controls the rotational speed of the engine to the predetermined rotational speed only when the rotational speed of the engine is higher than the predetermined rotational speed.

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