JP2018011430A - Vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a driver from feeling uncomfortable when an accelerator is off.SOLUTION: A vehicle performs, when an accelerator is off, a first control controlling a motor to apply brake force to the vehicle when not satisfying reduction condition of the brake force, and a second control controlling the motor to apply the smaller brake force to the vehicle relative to the brake force in the first control when satisfying the reduction condition thereof. Until the lapse of the prescribed time after shifting from the first control to the second control or shifting from the second control to the first control, a motor is controlled to change the brake force applied to the vehicle toward the brake force after shifting with a larger rate value in comparison to that after the lapse of the prescribed time. Thereby the brake force applied to the vehicle can be rapidly changed into the brake force after shifting when shifting from the first control to the second control or shifting from the second control to the first control to be capable of suppressing a driver from feeling uncomfortable.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an automobile, and more particularly, to an automobile provided with a motor for traveling.

  Conventionally, an automobile including an engine and a transmission has been proposed (see, for example, Patent Document 1). The transmission includes a clutch that is connected between the engine and a drive shaft coupled to the axle and capable of transmitting and releasing power between the engine and the drive shaft. In this vehicle, when the condition for executing inertial running is satisfied when the accelerator is off, the clutch is released, and the engine braking force acting on the vehicle is smaller than that during normal running where the clutch is engaged. doing.

JP 2014-083999 A

  As in the above-described automobile, when the accelerator is off, an automobile that switches the braking force may give the driver an unexpected feeling of idling when the braking force is reduced. Since such a feeling of running leads to a sense of incongruity, suppression is desired. As a technique for suppressing a sense of incongruity, there can be considered a technique of gradually changing the braking force toward a target value at a relatively small rate value when changing the braking force applied to the vehicle. In this case, it takes time for the braking force to reach the target value, which may cause the driver to feel uncomfortable. Suppression of such discomfort is recognized as an important issue even in an automobile equipped with a traveling motor.

  The main object of the automobile of the present invention is to suppress the driver from feeling uncomfortable when the accelerator is off.

  The automobile of the present invention has taken the following means in order to achieve the main object described above.

The automobile of the present invention
A motor for traveling,
A control device for controlling the motor;
A car equipped with
The controller is
When the accelerator is off, when the braking force reduction condition is not satisfied, the first control is performed to control the motor so that the braking force acts on the vehicle. When the reduction condition is satisfied, the first control is performed. Executing a second control for controlling the motor such that a braking force smaller than the braking force in the first control acts on the vehicle;
Further, the control device includes:
From the time when the first control is shifted to the second control, or until the predetermined time elapses from when the second control is shifted to the first control, the time after the predetermined time elapses is compared with And controlling the motor so that the braking force acting on the vehicle changes toward the braking force after the transition at a large rate value.
This is the gist.

  In this automobile of the present invention, when the braking force reduction condition is not satisfied when the accelerator is off, the first control for controlling the motor is executed so that the braking force acts on the vehicle, and the reduction condition is satisfied. When the vehicle is running, the second control is executed to control the motor so that a braking force smaller than the braking force in the first control acts on the vehicle. Furthermore, after the transition from the first control to the second control, or until the predetermined time elapses after the transition from the second control to the first control, it is larger than after the predetermined time has elapsed. The motor is controlled so that the braking force acting on the vehicle changes toward the braking force after the transition at the rate value. Thereby, when shifting from the first control to the second control or from the second control to the first control, the braking force acting on the vehicle can be quickly changed toward the braking force after the transition, A driver's discomfort can be suppressed.

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 control routine at the time of accelerator off performed by HVECU70 of an Example. It is explanatory drawing which shows an example of the map for request | requirement torque setting. It is explanatory drawing which shows an example of the time change of the braking force reduction flag Fbr and torque. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. It is a block diagram which shows the outline of a structure of the electric vehicle 220 of a modification.

  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. As shown, the hybrid vehicle 20 of the embodiment includes an engine 22, a planetary gear 30, motors MG1 and MG2, inverters 41 and 42, a battery 50, and a hybrid electronic control unit (hereinafter referred to as “HVECU”). 70.

  The engine 22 is configured as an internal combustion engine that outputs power using gasoline or light oil as a fuel. The operation of the engine 22 is controlled by an engine electronic control unit (hereinafter referred to as “engine ECU”) 24.

  Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM that stores a processing program, a RAM that temporarily stores data, an input / output port, and a communication port. . The engine ECU 24 receives signals from various sensors necessary to control the operation of the engine 22, for example, a crank angle θcr from a crank position sensor that detects the rotational position of the crankshaft 26 of the engine 22 from an input port. ing. Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 via an output port. The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 calculates the rotational speed Ne of the engine 22 based on the crank angle θcr from the crank position sensor 23.

  The planetary gear 30 is configured as a single pinion type planetary gear mechanism. The sun gear of planetary gear 30 is connected to the rotor of motor MG1. The ring gear of the planetary gear 30 is connected to a drive shaft 36 that is coupled to the drive wheels 39a and 39b via a differential gear 38. A crankshaft 26 of the engine 22 is connected to the carrier of the planetary gear 30 via a damper 28.

  The motor MG1 is configured as, for example, a synchronous generator motor, and the rotor is connected to the sun gear of the planetary gear 30 as described above. The motor MG2 is configured as, for example, a synchronous generator motor, and a rotor is connected to the drive shaft 36. Inverters 41 and 42 are connected to motors MG <b> 1 and MG <b> 2 and to battery 50 via power line 54. The motors MG1 and MG2 are driven to rotate by switching control of a plurality of switching elements (not shown) of the inverters 41 and 42 by a motor electronic control unit (hereinafter referred to as “motor ECU”) 40.

  Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . The motor ECU 40 receives signals from various sensors necessary for driving and controlling the motors MG1 and MG2, for example, rotational positions θm1 from rotational position detection sensors 43 and 44 that detect rotational positions of the rotors of the motors MG1 and MG2. , Θm2, etc. are input via the input port. From the motor ECU 40, switching control signals to a plurality of switching elements (not shown) of the inverters 41 and 42 are output via an output port. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 calculates the rotational speeds Nm1, Nm2 of the motors MG1, MG2 based on the rotational positions θm1, θm2 of the rotors of the motors MG1, MG2 from the rotational position detection sensors 43, 44.

  The battery 50 is configured as, for example, a lithium ion secondary battery or a nickel hydride secondary battery, and is connected to the inverters 41 and 42 via the power line 54. The battery 50 is managed by a battery electronic control unit (hereinafter referred to as “battery ECU”) 52.

  Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . Signals from various sensors necessary for managing the battery 50 are input to the battery ECU 52 via the input port. Examples of signals input to the battery ECU 52 include a battery voltage Vb from a voltage sensor 51 a installed between terminals of the battery 50, a battery current Ib from a current sensor 51 b attached to an output terminal of the battery 50, and a battery 50. The battery temperature Tb from the temperature sensor 51c attached to can be mentioned. The battery ECU 52 is connected to the HVECU 70 via a communication port. The battery ECU 52 calculates the storage ratio SOC based on the integrated value of the battery current Ib from the current sensor 51b. The storage ratio SOC is a ratio of the capacity of power that can be discharged from the battery 50 to the total capacity of the battery 50.

  Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU, and includes a ROM that stores a processing program, a RAM that temporarily stores data, an input / output port, and a communication port in addition to the CPU. Signals from various sensors are input to the HVECU 70 via input ports. Examples of the signal input to the HVECU 70 include an ignition signal from the ignition switch 80 and a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81. Here, the shift position SP includes a parking position (P position), a reverse position (R position), a neutral position (N position), a forward position (D position), and the like. Further, the accelerator opening Acc from the accelerator pedal position sensor 84 that detects the depression amount of the accelerator pedal 83, the brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, and the vehicle speed sensor 88 The vehicle speed V can also be mentioned. Furthermore, an eco-switch signal from the eco-switch 90 that instructs the eco-mode that gives higher priority to fuel efficiency than the normal mode can be cited as the travel mode Md. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port.

In the hybrid vehicle 20 of the embodiment thus configured, the required driving force of the drive shaft 36 is set based on the accelerator opening Acc and the vehicle speed V, and the required power corresponding to the required driving force is output to the drive shaft 36. In addition, the engine 22 and the motors MG1, MG2 are controlled to operate. As operation modes of the engine 22 and the motors MG1, MG2, there are the following modes (1) to (3).
(1) Torque conversion operation mode: The engine 22 is operated and 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 motors MG1 and MG2. (2) Charging / discharging operation mode: sum of required power and electric power necessary for charging / discharging of the battery 50. In this mode, the motor MG1 and MG2 are driven and controlled so that the required power is output to the drive shaft 36. The engine 22 is operated and controlled so that the power suitable for the engine 22 is output from the engine 22, and all or a part of the power output from the engine 22 is charged with the battery 50 by the planetary gear 30 and the motors MG1 and MG2. The motors MG1 and MG2 are driven so that the torque is converted by the motor and the required power is output to the drive shaft 36. Gosuru mode (3) motor drive mode: stop the operation of the engine 22, required power to drive control of the motor MG2 to be outputted to the drive shaft 36 mode

  In the hybrid vehicle 20 of the embodiment thus configured, the motor MG2 is controlled as follows when the accelerator is off during forward travel. In parallel with the control of motor MG2, switching control of a plurality of switching elements of inverter 41 is performed so that engine 22 is stopped and torque is not output from motor MG1 by cooperative control of HVECU 70, engine ECU 24, and motor ECU 40. To do.

  Next, the operation of the hybrid vehicle 20 of the embodiment thus configured, particularly the operation when the accelerator is turned off during forward traveling will be described. FIG. 2 is a flowchart illustrating an example of an accelerator-off time control routine executed by the HVECU 70 of the embodiment. This routine is repeatedly executed every predetermined time (for example, several msec) when the accelerator is off during forward traveling. In parallel with this routine, the HVECU 70, the engine ECU 24, and the motor ECU 40 control the switching of the plurality of switching elements of the inverter 41 so that the engine 22 is stopped and torque is not output from the motor MG1. .

  When this routine is executed, the HVECU 70 inputs the vehicle speed V, the braking force reduction flag Fbr, the elapsed time ttr, and the like (step S100). Here, the vehicle speed V is detected by the vehicle speed sensor 88. The braking force reduction flag Fbr is a flag indicating whether or not a reduction condition for reducing the braking force when the accelerator is off is satisfied. The braking force reduction flag Fbr is set to 0 when the eco switch 90 is off (in the normal mode), that is, when the reduction condition is not established, and when the eco switch 90 is on, ie, the reduction condition is established. The value 1 is set when The elapsed time ttr is the elapsed time after the braking force reduction flag Fbr is switched from the value 0 to the value 1 or from the value 1 to the value 0.

  Subsequently, the required torque Td * required for the vehicle (required for the drive shaft 36) is set based on the vehicle speed V and the braking force reduction flag Fbr (step S110). In the embodiment, the required torque Td * is determined in advance by storing the relationship between the vehicle speed V, the braking force reduction flag Fbr, and the required torque Td * in a ROM (not shown) as a required torque setting map. When the reduction flag Fbr is given, the corresponding required torque Td * is derived from this map and set. An example of the required torque setting map is shown in FIG. When the required torque Td * is negative, it means that a braking torque is required for the vehicle (drive shaft 36). As shown in the figure, the required torque Td * is set to be larger (the braking force is smaller) when the braking force reduction flag Fbr is 1 than when it is 0.

  Next, it is determined whether or not the elapsed time ttr is equal to or longer than the predetermined time tref (step S120). The predetermined time tref is a threshold value for determining whether or not to switch the rate value when changing the torque command Tm2 *, and is set to 400 ms, 500 ms, 600 ms, or the like, for example.

  When the elapsed time ttr is less than the predetermined time tref, that is, when the predetermined time tref has not elapsed since the value of the braking force reduction flag Fbr is switched, the torque command Tm2 * for the motor MG2 to be described later is changed. When the rate value R is set to the value R1 (step S130) and the elapsed time ttr is equal to or longer than the predetermined time tref, that is, when the predetermined time tref has elapsed after the value of the braking force reduction flag Fbr is switched, The rate value R is set to the value R2 (step S140). The values R1 and R2 are real numbers larger than the value 0 and smaller than the value 1. The value R1 is a relatively large value, for example, 0.60, 0.65, 0.70, etc. The value R2 is a smaller value than the value R1, and is, for example, 0.30, 0.35, 0.40 or the like.

  When the rate value R is set in this way, the rate value R changes from the previous Tm2 * (the torque command of the motor MG2 set when the previous routine is executed) toward the required torque Td * using the following equation (1). The temporary torque Tm2tmp, which is a temporary value of the torque command Tm2 * of the motor MG2, is set (step S150), and the temporary torque Tmp2tmp is limited by the required torque Td * using the following equation (2) or (3) Is set to the torque command Tm2 * of the motor MG2 and transmitted to the motor ECU 40 (step S160), and this routine is terminated. Receiving the torque command Tm2 *, the motor ECU 40 performs switching control of the plurality of switching elements of the inverter 42 so that the motor MG2 is driven by the torque command Tm2 *.

Tm2tmp = previous Tm2 * + R ・ (Td * -previous Tm2 *) / | Td * -previous Tm2 * | ... (1)
Tm2 * = min (Td *, Tm2tmp) ((Td * -previous Tm2 *) / | Td * -previous Tm2 * | is 1) ... (2)
Tm2 * = max (Td *, Tm2tmp) ((Td * -previous Tm2 *) / | Td * -previous Tm2 * | is the value -1)
... (3)

  By such control, when the braking force reduction flag Fbr is a value 1, the motor MG2 is driven by a torque command Tm2 * that changes toward a required torque Td * (smaller as a braking force) that is larger than when the value is 0. The motor MG2 is controlled to drive. Hereinafter, the control when the braking force reduction flag Fbr is 0 is referred to as “first control”, and the control when the braking force reduction flag Fbr is 1 is referred to as “second control”. Further, the predetermined time tref is changed until the predetermined time tref elapses after the value of the braking force reduction flag Fbr changes, that is, after the transition from the first control to the second control or from the second control to the first control. Until the predetermined time tref elapses, the braking force acting on the vehicle is directed toward the required torque Td * at a larger rate value R (value R1) than the rate value R (value R2) after the predetermined time tref has elapsed. The motor MG2 is controlled so as to change. Thereby, when control is transferred, the braking force can be applied to the vehicle quickly.

  FIG. 4 is an explanatory diagram illustrating an example of a temporal change in the braking force reduction flag Fbr and the torque. In the figure, in the time change of the torque, the solid line shows an example of the time change of the required torque Td *, and the broken line shows an example of the time change of the torque command Tm2 *. As shown in the figure, when the value of the braking force reduction flag Fbr changes, that is, when the control shifts from the first control to the second control or from the second control to the first control (time t1, t3), a predetermined time period is reached. Until tref elapses, the torque command Tm2 * is changed toward the required torque Td * after the transition at a relatively large rate value R (= R1) (time t2, t4). Thereby, the torque command Tm2 * of the motor MG2 can be quickly made the required torque Td * after the transition. When the torque command Tm2 * of the motor MG2 does not become the required torque Td * despite the transition from the first control to the second control or from the second control to the first control, the driver may feel uncomfortable. is there. In the embodiment, the torque command Tm2 * of the motor MG2 is quickly set to the required torque Td * after the shift, that is, the braking force acting on the vehicle can be quickly set as the braking force after the shift. Can be suppressed.

  In addition, after the braking force reduction flag Fbr changes and the predetermined time tref elapses, the torque command Tm2 * is requested to the required torque Td * at a rate value R (value R2) smaller than that before the predetermined time tref elapses. (From time t2 to t3 and after t4). As a result, after the braking force reduction flag Fbr is changed and the predetermined time tref has elapsed, that is, when the first control or the second control is being executed for a while, the torque command Tm2 * is slowly requested. Change toward Td *. As a result, it is possible to suppress a sudden change in the braking force acting on the vehicle even though the control is not shifted.

  In the hybrid vehicle 20 of the embodiment described above, when the accelerator is off, when the braking force reduction flag Fbr is 0, the first control is executed to control the motor MG2 so that the braking force acts on the vehicle. When the reduction flag Fbr is 1, the second control for controlling the motor MG2 is executed such that a braking force smaller than the braking force in the first control is applied to the vehicle. Furthermore, after the transition from the first control to the second control and until the predetermined time tref elapses after the transition from the second control to the first control, compared to the time after the predetermined time tref elapses. The motor MG2 is controlled so that the braking force acting on the vehicle changes toward the braking force (requested torque Td *) after the transition at a large rate value R (value R1). As a result, the braking force acting on the vehicle can be quickly changed toward the braking force after the transition, and the driver's uncomfortable feeling can be suppressed.

  In the hybrid vehicle 20 of the embodiment, the predetermined time tref has elapsed after the transition from the first control to the second control and until the predetermined time tref has elapsed since the transition from the second control to the first control. The torque command Tm2 * of the motor MG2 is changed toward the required torque Td * at a larger rate value R (value R1) than after that. The predetermined time tref has elapsed since the transition from the first control to the second control and the transition from the second control to the first control until the predetermined time tref has elapsed since the transition. The torque command Tm2 * of the motor MG2 may be changed toward the required torque Td * with a larger rate value R (value R1) than after that.

  In the hybrid vehicle 20 of the embodiment, the same rate value R (value R1) is obtained after the transition from the first control to the second control and until a predetermined time tref elapses from the transition from the second control to the first control. ), The torque command Tm2 * of the motor MG2 is changed toward the required torque Td *. Torque command of the motor MG2 at different rate values from when the first control is shifted to the second control until the predetermined time tref elapses and when the predetermined time tref elapses from the second control to the first control. Tm2 * may be changed toward the required torque Td *.

  In the hybrid vehicle 20 of the embodiment, the same rate value R (value) after the transition from the first control to the second control and after a predetermined time tref has elapsed from the transition from the second control to the first control. In R2), the torque command Tm2 * of the motor MG2 is changed toward the required torque Td *. After the time when the predetermined time tref has elapsed since the transition from the first control to the second control, and after the time when the predetermined time tref has elapsed since the transition from the second control to the first control, the motor MG2 has different rate values. The torque command Tm2 * may be changed toward the required torque Td *.

  In the hybrid vehicle 20 of the embodiment, the engine ECU 24, the motor ECU 40, and the HVECU 70 are provided. However, the engine ECU 24, the motor ECU 40, and the HVECU 70 may be configured as a single electronic control unit.

  In the hybrid vehicle 20 of the embodiment, the engine 22 and the motor MG1 are connected to the drive shaft 36 connected to the drive wheels 39a and 39b via the planetary gear 30, and the motor MG2 is connected to the drive shaft 36. However, as shown in the modified hybrid vehicle 120 of FIG. 5, the motor MG is connected to the drive shaft 36 connected to the drive wheels 39a and 39b via the transmission 130 and the clutch 129 is attached to the rotation shaft of the motor MG. It is good also as a structure which connects the engine 22 via. Moreover, as shown in the electric vehicle 220 of the modification of FIG. 6, it is good also as a structure of the electric vehicle which connects the motor MG for driving | running | working to the drive shaft 36 connected with the drive wheels 39a and 39b. In other words, any configuration may be used as long as it includes a traveling motor.

  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 motor MG2 corresponds to a “motor”, and the HVECU 70 and the motor ECU 40 correspond to a “control device”.

  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 automobile manufacturing industry.

  20, 120 Hybrid vehicle, 22 engine, 23 crank position sensor, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 planetary gear, 36 drive shaft, 38 differential gear, 39a, 39b drive wheel, 40 Motor electronic control unit (motor ECU), 41, 42 Inverter, 43, 44 Rotation position sensor, 50 battery, 51a Voltage sensor, 51b Current sensor, 51c Temperature sensor, 52 Battery electronic control unit (battery ECU), 54 Electric power Line, 70 hybrid electronic control unit (HV ECU), 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position Deployment sensor, 85 brake pedal, 86 a brake pedal position sensor, 88 vehicle speed sensor, 90 eco switch, 129 the clutch, 130 transmission, 220 electric vehicle, MG, MG1, MG2 motor

Claims (1)

A motor for traveling,
A control device for controlling the motor;
A car equipped with
The controller is
When the accelerator is off, when the braking force reduction condition is not satisfied, the first control is performed to control the motor so that the braking force acts on the vehicle. When the reduction condition is satisfied, the first control is performed. Executing a second control for controlling the motor such that a braking force smaller than the braking force in the first control acts on the vehicle;
Further, the control device includes:
From the time when the first control is shifted to the second control, or until the predetermined time elapses from when the second control is shifted to the first control, the time after the predetermined time elapses is compared with And controlling the motor so that the braking force acting on the vehicle changes toward the braking force after the transition at a large rate value.
Automobile.

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