JP2012148652A - Hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more reliably determine that an accelerator operation and a brake operation are simultaneously performed even when abnormal conditions occur in a sensor or the like for detecting a brake operation and the brake operation cannot be properly detected.SOLUTION: When brake fail is determined, it is determined whether accelerator opening Acc is equal to or more than a threshold Aref and a rotation speed variation amount ΔN is less than a threshold Nref determined as a negative value (S150, S160). When the accelerator opening Acc is equal to or more than the threshold Aref and the rotation speed variation amount ΔN is equal to or more than the threshold Nref, accelerator and brake simultaneous operations are determined, in which an accelerator pedal 83 and a brake pedal 85 are simultaneously depressed (S170). Accordingly, the accelerator and brake simultaneous operations are more reliably determined even during the brake fail.

Description

  The present invention relates to a hybrid vehicle having an internal combustion engine and an electric motor.

  Conventionally, as a travel control device mounted on this type of hybrid vehicle, when the accelerator pedal and the brake pedal are depressed at the same time, the travel motor is applied to the travel motor within a range where the current flowing to the travel motor is below a reference value. A device that controls the flowing current has been proposed (see, for example, Patent Document 1). In this apparatus, by performing the above-described control, the vehicle can be driven without applying an overcurrent to the driving motor.

JP 7-39001 A

  In a hybrid vehicle, when the accelerator pedal and the brake pedal are depressed at the same time, an overcurrent is not applied to the motor as in the above-described device, the generator and the motor are not over-rotated, the generator and the motor Protection control is performed such that the battery that exchanges power with the battery is not overcharged, but when an abnormality occurs in the sensor that detects the depression of the brake pedal, the accelerator pedal and the brake pedal are depressed simultaneously. Cannot be properly judged.

  The hybrid vehicle of the present invention can more reliably determine that the accelerator operation and the brake operation are simultaneously performed even when a sensor or the like that detects the brake operation is abnormal and the brake operation cannot be detected properly. The main purpose is to more reliably prevent the generator from over-rotating when the accelerator operation and the brake operation are performed simultaneously.

  The hybrid vehicle of the present invention employs the following means in order to achieve the main object described above.

The hybrid vehicle of the present invention
A hybrid vehicle having an internal combustion engine and an electric motor,
Brake operation detecting means for detecting the brake operation;
An accelerator opening detecting means for detecting an accelerator opening based on an accelerator operation;
Drive wheel rotation speed detection means for detecting the rotation speed of the drive wheel;
The detected accelerator opening is equal to or greater than a predetermined opening while the brake detecting means is malfunctioning, and the detected change in the rotational speed of the drive wheels is a predetermined change. When the deceleration change is greater than or equal to a degree, a determination unit that determines an accelerator brake simultaneous operation in which an accelerator operation for acceleration and a brake operation for deceleration are performed simultaneously;
It is a summary to provide.

  In the hybrid vehicle of the present invention, the accelerator opening is equal to or larger than a predetermined opening while the brake detection means is abnormal, and the change in the rotational speed of the drive wheel is a predetermined predetermined change. When the deceleration change is as described above, it is determined whether the accelerator brake simultaneous operation is performed in which the accelerator operation for acceleration and the brake operation for deceleration are simultaneously performed. As a result, even when an abnormality occurs in the brake detection means, it is possible to more reliably determine that the accelerator operation for acceleration and the brake operation for deceleration are performed simultaneously.

  In such a hybrid vehicle of the present invention, the generator and the three rotating elements are connected to the rotating shaft of the generator, the output shaft of the internal combustion engine, and the driving shaft connected to the driving wheel in order from the left on the alignment chart. A planetary gear mechanism that has been detected, a generator rotation speed detection means for detecting the rotation speed of the generator, and the generator rotation speed detected while the accelerator brake simultaneous operation is determined by the determination means. And a prohibiting means for prohibiting fuel supply to the internal combustion engine when the engine speed exceeds a predetermined number of revolutions. If it carries out like this, the rotation speed of an internal combustion engine can be reduced and the increase in the rotation speed of a generator can be suppressed. Thereby, it can prevent more reliably that a generator overrotates.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. It is a flowchart which shows an example of the simultaneous operation determination process routine performed by the electronic control unit for hybrid 70 of an Example.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. In the hybrid vehicle 20 of the embodiment, as shown in the figure, a carrier is connected to an engine 22 that uses gasoline, light oil, or the like as fuel, and a crankshaft 26 of the engine 22, and drive wheels 38 a and 38 b are connected to a differential gear 37. A planetary gear 30 having a ring gear connected to the connected drive shaft 36, a motor MG1 configured as a synchronous generator motor, for example, and a rotor connected to a sun gear of the planetary gear 30, and a rotor configured as a synchronous generator motor, for example. A motor MG2 connected to the drive shaft 36, a battery 50 that exchanges electric power with the motors MG1 and MG2, a brake actuator 92 for controlling the brakes of the drive wheels 38a and 39b and the driven wheels 39a and 39b, and the entire vehicle Controlling hybrid electronic control unit 70 , Comprising a.

  The engine 22 is subjected to operation control such as fuel injection control, ignition control, and intake air amount control by an engine electronic control unit (hereinafter referred to as engine ECU) 24. Signals from various sensors that detect the operating state of the engine 22 are input to the engine ECU 24, and the engine ECU 24 controls driving to a throttle valve, a fuel injection valve, a spark plug, a variable valve timing mechanism, and the like (not shown). A signal is being output. The engine ECU 24 is in communication with the hybrid electronic control unit 70, controls the operation of the engine 22 by a control signal from the hybrid electronic control unit 70, and, if necessary, transmits data related to the operating state of the engine 22 to the hybrid electronic control. Output to unit 70. The engine ECU 24 also calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22, based on a crank position from a crank position sensor (not shown) attached to the crankshaft 26.

  Both the motor MG1 and the motor MG2 are driven and controlled by a motor electronic control unit (hereinafter referred to as a motor ECU) 40. The motor ECU 40 detects signals necessary for driving and controlling the motors MG1 and MG2, such as signals from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and current sensors (not shown). The phase current applied to the motors MG1 and MG2 to be applied is input, and a switching control signal to the inverters 41 and 42 is output from the motor ECU 40. The motor ECU 40 is in communication with the hybrid electronic control unit 70, controls the driving of the motors MG1 and MG2 by a control signal from the hybrid electronic control unit 70, and, if necessary, data on the operating state of the motors MG1 and MG2. Output to the hybrid electronic control unit 70. The motor ECU 40 also calculates the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on signals from the rotational position detection sensors 43 and 44.

  The battery 50 is managed by a battery electronic control unit (hereinafter referred to as a battery ECU) 52. The battery ECU 52 receives signals necessary for managing the battery 50, for example, a voltage between terminals from a voltage sensor installed between terminals of the battery 50, and a current sensor attached to an output terminal on the positive electrode side of the battery 50. The charging / discharging current, the battery temperature from the temperature sensor attached to the battery 50, and the like are input, and data on the state of the battery 50 is output to the hybrid electronic control unit 70 by communication as necessary. In addition, the battery ECU 52 manages the battery 50, and a power storage ratio that is a ratio of the amount of power stored in the battery 50 that can be discharged from the battery 50 based on the integrated value of the charge / discharge current detected by the current sensor. Calculate the SOC.

  The brake actuator 92 has a braking torque corresponding to the share of the brake in the braking force applied to the vehicle by the pressure (brake pressure) of the brake master cylinder 90 and the vehicle speed V generated when the brake pedal 85 is depressed. The braking torque acts on the drive wheels 38a, 38b and the driven wheels 39a, 39b regardless of the pressure of the brake wheel cylinders 96a-96d or the depression of the brake pedal 85 so as to act on the wheel 38b and the driven wheels 39a, 39b. The hydraulic pressure of the brake wheel cylinders 96a to 96d can be adjusted. The brake actuator 92 is controlled by a brake electronic control unit (hereinafter referred to as a brake ECU) 94. The brake ECU 94 communicates with the hybrid electronic control unit 70, and controls the drive of the brake actuator 92 by a control signal from the hybrid electronic control unit 70, or the data regarding the state of the brake actuator 92 is hybridized as necessary. Output to the electronic control unit 70.

  The hybrid electronic control unit 70 is configured as a microprocessor centered on the CPU 72, and in addition to the CPU 72, a ROM 74 for storing processing programs, a RAM 76 for temporarily storing data, an input / output port and communication not shown. And a port. The hybrid electronic control unit 70 includes an ignition signal from an ignition switch (not shown), a shift position SP from a shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator pedal position sensor that detects the amount of depression of the accelerator pedal 83. 84, the accelerator pedal opening Acc from 84, the brake pedal position BP from the brake pedal position sensor 86 for detecting the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the pressure (brake pressure) attached to the brake master cylinder 90. The brake pressure Pb from the brake pressure sensor 91 is detected via the input port. The hybrid electronic control unit 70 is connected to the engine ECU 24, the motor ECU 40, the battery ECU 52, and the brake ECU 94 via a communication port. The engine ECU 24, the motor ECU 40, the battery ECU 52, and the brake ECU 94 are connected to various control signals and data. We are exchanging.

  The hybrid vehicle 20 of the embodiment configured in this way calculates a required torque to be output to the drive shaft 36 based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal 83 by the driver. The operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the torque is output to the drive shaft. As the operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that power corresponding to the required power is output from the engine 22, and all of the power output from the engine 22 is transmitted to the planetary gear 30 and the motor MG1. The motor MG2 converts the torque of the motor MG1 and the motor MG2 so that the motor MG1 and the motor MG2 are driven and controlled, and the power suitable for the sum of the required power and the power required for charging and discharging the battery 50 is obtained. The operation of the engine 22 is controlled so as to be output from the engine 22, and all or a part of the power output from the engine 22 with charging / discharging of the battery 50 is converted by the planetary gear 30, the motor MG1, and the motor MG2. Accordingly, the required power is output to the drive shaft 36. Charge-discharge drive mode for driving and controlling the motor MG1 and the motor MG2, there is a motor operation mode in which operation control to output a power commensurate to stop the operation of the engine 22 to the required power from the motor MG2 to the drive shaft 36.

  Next, the operation of the hybrid vehicle 20 of the embodiment thus configured, particularly when the accelerator pedal 83 and the brake pedal 85 are depressed at the same time when an abnormality occurs in the brake pedal position sensor 86 and the brake pressure sensor 91, is described. The operation will be described. FIG. 2 is a flowchart illustrating an example of a simultaneous operation determination process routine executed by the hybrid electronic control unit 70 according to the embodiment. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When the simultaneous operation determination processing routine is executed, first, the hybrid electronic control unit 70 first determines the accelerator opening Acc from the accelerator pedal position sensor 84, the brake pressure Pb from the brake pressure sensor 91, and the rotation speed of the motors MG1 and MG2. Nm1, Nm2, fail information and other data necessary for the determination of the simultaneous operation of the accelerator brake when the accelerator pedal 83 and the brake pedal 85 are simultaneously depressed are input (step S100), and the previous number of revolutions Nm2 of the input motor MG2 A rotational speed change amount ΔN obtained by subtracting the rotational speed Nm2 (hereinafter referred to as the previous Nm2) of the motor MG2 input when the routine is executed is calculated (step S110). Here, the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 are calculated based on the rotational position detection sensors 43 and 44 and input from the motor ECU 40 by communication. The fail information includes sensor errors such as a shift position sensor 82, an accelerator pedal position sensor 84, a brake pedal position sensor 86, and a vehicle speed sensor 88 detected by an abnormality determination processing routine (not shown), an abnormality in the motors MG1 and MG2, an inverter 41, When an abnormality 42 is detected, the hybrid electronic control unit 70 is inputted by reading what is stored in a predetermined area of a memory such as a flash memory (not shown) provided in the hybrid electronic control unit 70. The rotation speed change amount ΔN is the change amount of the rotation speed Nm2 of the motor MG2, and the rotor of the motor MG2 is attached to the drive shaft 36 connected to the drive wheels 38a and 38b via the differential gear 37. In consideration of the above, it indicates the degree of change in the rotational speed of the drive wheels 38a, 38b.

  Next, it is determined whether or not a brake failure has occurred based on the fail information, that is, whether or not an abnormality has occurred in the brake relationship such as the brake pedal position sensor 86 and the brake pressure sensor 91 (step S120). When not failing, it is determined that the brake pedal position sensor 86 and the brake pressure sensor 91 are functioning normally, and whether or not the accelerator opening Acc is equal to or greater than the threshold value Aref and the brake pressure Pb is equal to or greater than the threshold value Pref. Is determined (steps S130 and S140). Here, the threshold Aref is a threshold provided for determining whether or not the accelerator pedal 83 is depressed, and for example, 5% or 7% can be used as the accelerator opening degree Acc. Further, the threshold value Pref is a threshold value provided for determining whether or not the brake pedal 85 is depressed, and is a pressure slightly higher than the pressure of the brake master cylinder 90 when the brake pedal 85 is released. Can be used. If the accelerator opening degree Acc is less than the threshold value Aref, or if the brake pressure Pb is less than the threshold value Pref even if the accelerator opening degree Acc is greater than or equal to the threshold value Aref, it is determined that the accelerator brake simultaneous operation is not performed, and this routine is terminated.

  On the other hand, if it is determined in steps S130 and S140 that the accelerator opening Acc is equal to or greater than the threshold value Aref and the brake pressure Pb is equal to or greater than the threshold value Pref (step S170), it is determined that the accelerator brake is operated simultaneously (step S170). It is determined whether or not the number Nm1 is equal to or greater than the threshold value Nmax (step S180). When the rotational speed Nm1 of the motor MG1 is equal to or greater than the threshold value Nmax, the engine ECU 24 is instructed to perform fuel cut to stop fuel supply to the engine 22 ( Step S190), this routine is terminated, and when the rotational speed Nm1 of the motor MG1 is less than the threshold value Nmax, it is determined that the fuel cut is unnecessary, the fuel cut is canceled (step S200), and this routine is terminated. Here, the threshold value Nmax is a threshold value for determining whether the motor MG1 may be in a state (over-rotation state) that may exceed the upper limit rotational speed, and the rotational speed of the motor MG1 is relatively high. It can be set as a rotational speed that is larger but smaller than the upper rotational speed. When the accelerator brake is operated simultaneously, the rotational speed Ne of the engine 22 increases to increase the power output from the engine 22 by depressing the accelerator pedal 83, but the vehicle speed V decreases by depressing the brake pedal 85. The number of rotations of 36 becomes small. That is, the rotational speed of the ring gear 32 of the planetary gear 30 decreases and the rotational speed of the carrier 34 increases. For this reason, due to the characteristics of the planetary gear 30, the number of revolutions of the sun gear 31, that is, the number of revolutions Nm1 of the motor MG1, increases, and in some cases, the engine rotates excessively. For this reason, by performing fuel cut of the engine 22 when the rotational speed Nm1 of the motor MG1 is equal to or greater than the threshold value Nmax, the rotational speed Ne * of the engine 22 is reduced, and an increase in the rotational speed Nm1 of the motor MG1 is suppressed. . As a result, over-rotation of the motor MG1 can be prevented more reliably.

  When it is determined in step S120 that a brake failure is occurring, it is determined whether or not the accelerator opening Acc is equal to or greater than the threshold value Aref and the rotational speed change amount ΔN is less than the threshold value Nref determined as a negative value ( Steps S150 and S160). Here, the threshold value Nref is used to determine whether or not the rotational speed of the drive shaft 36 is decreasing, and can be set as a value slightly smaller than the value 0. If the accelerator opening degree Acc is less than the threshold value Aref, or even if the accelerator opening degree Acc is greater than or equal to the threshold value Aref, if the rotational speed change amount ΔN is greater than or equal to the threshold value Nref, it is determined that the accelerator brake simultaneous operation is not performed, and this routine is terminated. To do. On the other hand, when it is determined that the accelerator opening degree Acc is equal to or greater than the threshold value Aref and the rotational speed change amount ΔN is less than the threshold value Nref, it is determined that the accelerator brake is simultaneously operated (step S170), and the rotational speed Nm1 of the motor MG1 It is determined whether or not this is the case (step S180). When the rotational speed Nm1 of the motor MG1 is equal to or greater than the threshold value Nmax, the engine ECU 24 is instructed to perform fuel cut to stop fuel supply to the engine 22, that is, to the engine 22. Is instructed to prohibit fuel injection (step S190), and this routine is terminated. When the rotational speed Nm1 of the motor MG1 is less than the threshold value Nmax, it is determined that fuel cut is unnecessary and the fuel cut is canceled (step S200). This routine is terminated. When it is determined that the accelerator opening degree Acc is equal to or greater than the threshold value Aref and the rotational speed change amount ΔN is less than the threshold value Nref, it is determined that the accelerator brake simultaneous operation is performed when the rotational speed Nm2 of the motor MG2 is decreasing. This is based on the fact that the possibility that the driver is stepping on the brake pedal 85 is high because the rotational speed of the drive wheels 38a, 38b is decreasing.

  According to the hybrid vehicle 20 of the embodiment described above, when it is determined that a brake failure is occurring, the accelerator opening Acc is equal to or greater than the threshold Aref, and the threshold value Nref in which the rotation speed change amount ΔN is set to a negative value. The accelerator pedal 83 and the brake pedal 85 are depressed at the same time when the accelerator opening degree Acc is equal to or greater than the threshold value Aref and the speed change amount ΔN is during deceleration with a value less than the threshold value Nref. By determining the simultaneous operation of the accelerator brake, it is possible to more reliably determine the simultaneous operation of the accelerator brake even during a brake failure. In addition, even during the brake failure, the fuel cut that stops the fuel supply to the engine 22 is performed when the rotational speed Nm1 of the motor MG1 is equal to or greater than the threshold value Nmax during the determination of the simultaneous accelerator brake operation more reliably. It is possible to more reliably prevent the motor MG1 from over-rotating.

  In the hybrid vehicle 20 of the embodiment, the determination process of the simultaneous operation of the accelerator brake during the brake failure is applied to the configuration including the engine 22, the planetary gear 30, the motor MG1, and the motor MG2, but any configuration including the engine and the motor is used. The determination process of the accelerator brake simultaneous operation during the brake failure may be applied to the configuration of the hybrid vehicle.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the engine 22 corresponds to the “internal combustion engine”, the motor MG2 corresponds to the “electric motor”, the motor MG1 corresponds to the “generator”, the planetary gear 30 corresponds to the “planetary gear mechanism”, and the brake pedal. The position sensor 86 and the brake pressure sensor 91 correspond to “brake operation detecting means”, the accelerator pedal position sensor 84 corresponds to “accelerator opening degree detecting means”, and rotational position detection for detecting the rotational speed Nm2 of the motor MG2. The sensor 44 and the motor ECU 40 correspond to “driving wheel rotational speed detection means”, the accelerator opening Acc is equal to or larger than the threshold value Aref during the brake failure, and the rotational speed change amount ΔN is less than the threshold value Nref determined as a negative value. Hybrid power for executing the simultaneous operation determination processing routine of FIG. The control unit 70 corresponds to the "determination means".

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the manufacturing industry of hybrid vehicles.

  20 hybrid vehicle, 22 engine, 24 electronic control unit for engine (engine ECU), 26 crankshaft, 30 planetary gear, 36 drive shaft, 37 differential gear, 38a, 38b drive wheel, 39a, 39b driven wheel, 40 electronic control for motor Unit (motor ECU), 41, 42 Inverter, 43, 44 Rotation position detection sensor, 50 battery, 52 Battery electronic control unit (battery ECU), 70 Hybrid electronic control unit, 81 Shift lever, 82 Shift position sensor, 83 Accelerator pedal, 84 Accelerator pedal position sensor, 85 Brake pedal, 86 Brake pedal position sensor, 88 Vehicle speed sensor, 90 Brake master cylinder, 91 Brake pressure sensor 92 brake actuator, 94 electronic control unit (brake ECU) for braking, 96A～96d brake wheel cylinders, MG1, MG2 motor.

Claims (2)

A hybrid vehicle having an internal combustion engine and an electric motor,
Brake operation detecting means for detecting the brake operation;
An accelerator opening detecting means for detecting an accelerator opening based on an accelerator operation;
Drive wheel rotation speed detection means for detecting the rotation speed of the drive wheel;
The detected accelerator opening is equal to or greater than a predetermined opening while the brake detecting means is malfunctioning, and the detected change in the rotational speed of the drive wheels is a predetermined change. When the deceleration change is greater than or equal to a degree, a determination unit that determines an accelerator brake simultaneous operation in which an accelerator operation for acceleration and a brake operation for deceleration are performed simultaneously;
A hybrid car with The hybrid vehicle according to claim 1,
A generator,
A planetary gear mechanism in which three rotating elements are connected to a rotating shaft of the generator, an output shaft of the internal combustion engine, and a driving shaft coupled to the driving wheel in order from the left on the alignment chart;
Generator rotational speed detection means for detecting the rotational speed of the generator;
Prohibition of prohibiting fuel supply to the internal combustion engine when the detected speed of the generator exceeds a predetermined speed while the accelerator brake simultaneous operation is determined by the determining means Means,
A hybrid car with

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