JP2014133495A - Control device for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve hill-climbing performance after a driving wheel on a first axle side slips and a motor to enter a motor lock state, and the driving wheel recovers from the slip thereafter.SOLUTION: If a front wheel slips when a rear wheel-side motor enters a motor lock state, a power supply time ts which is shorter than when the front wheel does not slip is set, and a small decrease rate Rd is set (S150, S160). Then the motor is controlled so as to decrease in torque at a decrease rate Rd from the timing which is the power supply time ts after the motor enters the motor lock state. Consequently, the total driving force of the vehicle after the slip of the front wheel is removed can be made larger.

Description

  The present invention relates to an automobile control device.

  Conventionally, this type of vehicle control device is mounted on a vehicle that travels using the power from the motor, and when the motor lock of the motor is determined, the motor drive force is lower than the normal value according to the drive force requirement. When the motor lock release is determined as a value, there has been proposed one that returns the driving force of the motor to the normal value (see, for example, Patent Document 1). In this control device, the drive force change rate when changing the drive force between the normal value and the limit value is set based on the road surface gradient, thereby improving vehicle controllability when the motor is locked or when the motor lock is released. I am trying.

JP 2007-329982 A

  In an automobile including a power output device connected to a first axle (for example, a front-wheel axle) and a motor connected to a second axle (for example, a rear-wheel axle), In some cases, the drive wheel (for example, the front wheel) on the axle side slips and the motor enters a motor lock state. In this case, the climbing performance after the slip of the driving wheel (for example, the front wheel) on the first axle side is eliminated by reducing the driving force by the grip between the tire and the road surface as a whole by reducing the driving force of the motor. One of the issues is to further improve

  The main object of the control apparatus for an automobile of the present invention is to improve the climbing performance after the driving wheel on the first axle side slips and the motor is in a motor lock state and then the slip is eliminated.

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

The vehicle control apparatus of the present invention is
A vehicle control device comprising a power output device connected to a first axle and a motor connected to a second axle,
When the first axle side drive wheel, which is the drive wheel to which the first axle is connected, is slipping when the motor is in a motor lock state, the first axle side drive wheel is not slipping. Controlling the motor so that the torque of the motor decreases gradually from an early timing,
It is characterized by that.

  In the automobile control apparatus of the present invention, when the motor connected to the second axle is in the motor lock state, the first axle-side drive wheel that is the drive wheel to which the first axle is connected slips. When the first axle side driving wheel is not slipping, the motor is controlled so that the torque of the motor is gradually reduced from the earlier timing. Therefore, when the power is output from the power output device and the motor, when the first axle side drive wheel slips and the motor enters the motor lock state, the torque of the motor is more gently reduced. By reducing the torque of the motor, the driving force (grip driving force) due to the grip between the tire and the road surface as a whole of the vehicle is decreased, and the grip driving force after the slip of the first axle side driving wheel is eliminated is further increased. be able to. As a result, it is possible to improve the climbing performance after the first axle side drive wheel slips on the uphill road and the motor is in the motor lock state and the slip is subsequently eliminated.

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 torque reduction related value setting routine at the time of a lock | rock performed by the electronic control unit 70 of an Example. It is explanatory drawing which shows an example of the energization time setting map. It is explanatory drawing which shows an example of the map for a reduction rate setting. Explanatory drawing which shows an example of the state of the time change of the slip determination when the front wheels 38a, 38b slip and the motor 42 is determined to be in the motor locked state, and the front wheel side, the rear wheel side, and the overall grip driving force Tf, Tr, Tto. It is. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 220 of a modified example. FIG. 11 is a configuration diagram illustrating an outline of a configuration of a modified example of an electric vehicle 320.

  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 in the figure, the hybrid vehicle 20 of the embodiment shifts the power from the engine 32 and the engine 32 and outputs it to a drive shaft 36 connected to the front wheels 38a and 38b via a front differential gear 37. , A motor 42 for inputting / outputting power to / from a drive shaft 46 connected to the rear wheels 48a, 48b via a rear differential gear 47, an inverter 44 for driving the motor 42, and a lithium ion secondary, for example. A battery 50 that is configured as a secondary battery and exchanges electric power with the motor 42 via an inverter 44 and an electronic control unit 70 that controls the entire vehicle are provided. Here, the electronic control unit 70 corresponds to the control device of the automobile.

  The motor 42 is configured as a well-known synchronous generator motor having a rotor in which a permanent magnet is embedded and a stator around which a three-phase coil is wound. The inverter 44 is configured as a known inverter having six transistors as switching elements and six diodes connected in parallel to each transistor in the reverse direction.

  Although not shown, the electronic control unit 70 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, and an input / output port in addition to the CPU. The electronic control unit 70 includes signals from various sensors that detect the operating state of the engine 32, signals from various sensors that detect the state of the transmission 34, and a rotational position detection sensor that detects the rotational position of the rotor of the motor 42. Temperature sensor 45 for detecting the rotational position θm of the rotor of the motor 42 from the motor 42, the phase current of the motor 42 from the current sensor attached to the connection line (power line) between the motor 42 and the inverter 44, and the element temperature of the inverter 44. Inverter voltage Tinv, voltage Vb between terminals from a voltage sensor attached between terminals of battery 50, charge / discharge current (discharge side is a positive value) Ib from a current sensor attached to an output terminal of battery 50, battery 50, the battery temperature Tb from the temperature sensor attached to 50, the ignition switch 80 from the ignition switch A position signal, a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, an accelerator opening Acc from the accelerator pedal position sensor 84 that detects a depression amount of the accelerator pedal 83, and a depression amount of the brake pedal 85 The brake pedal position BP from the brake pedal position sensor 86 for detecting the vehicle speed, the vehicle speed V from the vehicle speed sensor 88, the rotational speed Nf of the front wheel from the rotational speed sensor 89 for detecting the rotational speed of the front wheels 38a, 38b, and the rear wheels 48a, 48b. The rear wheel rotational speed Nr and the like from the rotational speed sensor that detects the rotational speed are input via the input port. From the electronic control unit 70, an operation control signal to the engine 32, a drive control signal to the transmission 34, a switching control signal to each transistor of the inverter 44, and the like are output via an output port. In the hybrid vehicle 20 of the embodiment, the shift position SP includes a parking position (P position), a neutral position (N position), a drive position (D position), a reverse position (R position), and the like.

  The electronic control unit 70 calculates the electrical angle θe and the rotational speed Nm of the rotor of the motor 42 based on the rotational position of the rotor of the motor 42 detected by the rotational position detection sensor, or the battery 50 detected by the current sensor. Based on the charging / discharging current of the battery 50, the storage ratio SOC, which is the ratio of the amount of power that can be discharged from the battery 50 at that time, to the total capacity is calculated, or the battery 50 is charged based on the calculated storage ratio SOC and the battery temperature Tb. The input / output limits Win and Wout, which are the maximum allowable power that may be discharged, are calculated.

  In the hybrid vehicle 20 of the embodiment configured as described above, the electronic control unit 70 sets the required torque Td * for traveling according to the accelerator opening Acc from the accelerator position sensor 84 and the vehicle speed V from the vehicle speed sensor 88. The target torque to be output to the drive shaft 36 by multiplying the set required torque Td * by the torque distribution kf of the front wheels 38a, 38b among the torque distributions kf, kr (kf + kr = 1) of the front and rear wheels 38a, 38b, 48a, 48b. Tf * is set, the target torque Te * to be output from the engine 32 is set based on the target torque Tf * and the transmission gear ratio Gf, and the torque distribution kr of the rear wheels 48a, 48b is set to the required torque Td *. Is set to the target torque Tr * to be output to the drive shaft 46, and the set target torque Tr * is set to the temporary torque Tmrt of the motor 42. p is set, the input / output limits Win and Wout of the battery 50 are divided by the rotational speed Nm of the motor 42, the torque limits Tmrmin and Tmrmax of the motor 42 are set, and the temporary torque Tmrtmp is limited by the torque limits Tmrmin and Tmrmax. A torque command Tm * for the motor 42 is set. The engine 32 is controlled to be driven with the target torque Te *, and the motor 42 is controlled to be driven with the torque command Tm *. The transmission 34 is controlled so that the gear position (speed ratio) becomes a target gear speed (target speed ratio) corresponding to the vehicle speed V and the required torque Td *.

  Further, in the hybrid vehicle 20 of the embodiment, when the motor 42 is determined to be in the motor locked state, the torque from the motor 42 is decreased after a certain amount of time has elapsed. This is because when the motor 42 is determined to be in the motor locked state, the current flows only in a specific phase among the three-phase coils of the motor 42 and the temperature rise of the motor 42 and the inverter 44 is easily promoted. This is to prevent these from overheating. The determination of the motor lock state of the motor 42 is, for example, that the accelerator opening Acc is equal to or greater than a threshold value and the torque command Tm * of the motor 42 is equal to or greater than the threshold value at a position where the shift position SP can travel (D position or R position). Nevertheless, it can be performed when the vehicle speed V is at or near the value 0 and when a predetermined time elapses, or when the current of any phase of the motor 42 is equal to or greater than the threshold value for a predetermined time.

  Next, the operation of the hybrid vehicle 20 of the embodiment thus configured, particularly the operation when the motor 42 is determined to be in the motor lock state will be described. FIG. 2 is a flowchart illustrating an example of a lock-time torque decrease related value setting routine executed by the electronic control unit 70 of the embodiment. This routine is executed when it is determined that the motor 42 is in the motor lock state.

  When the lock torque reduction related value setting routine is executed, the electronic control unit 70 first inputs data such as the front wheel rotational speed Nf, the rear wheel rotational speed Nr, and the inverter energization current Iinv from the rotational speed sensors 89 and 90. (Step S100), the rear wheel rotational speed Nr is subtracted from the input front wheel rotational speed Nf to calculate the rotational speed difference ΔNfr between the front wheels 38a, 38b and the rear wheels 48a, 48b (Step S110). Here, the inverter energization current Iinv uses the maximum value among the currents of the respective phases of the motor 42 from a current sensor (not shown).

  Subsequently, the calculated rotation speed difference ΔNfr is compared with a slip determination threshold value Nfrref (step S120). When the rotation speed difference ΔNfr is less than the threshold value Nfrref, it is determined that the front wheels 38a and 38b are not slipping and slip determination is performed. A value 0 is set in the flag Fs (step S130), and when the rotational speed difference ΔNfr is equal to or greater than the threshold value Nfrref, it is determined that the front wheels 38a and 38b are slipping and a value 1 is set in the slip determination flag Fs (step S140). ).

  Then, based on the inverter energization current Iinv and the slip determination flag Fs, an energization time ts as a time until the torque from the motor 42 starts to decrease is set (step S150), and the set energization time ts and the inverter energization current are set. Based on Iinv, a reduction rate Rd is set as a rate value when the torque of the motor 42 is reduced (step S160), and this routine ends. When the energization time ts and the decrease rate Rd are thus set, the motor 42 is controlled so that the torque of the motor 42 is reduced at the decrease rate Rd from the timing when the energization time ts has elapsed since the motor 42 is determined to be in the motor lock state.

  Here, the energization time ts and the decrease rate Rd are determined so that the motor 42 and the inverter 44 do not exceed their allowable upper limit temperatures. In the embodiment, the energization time ts is determined in advance by storing the relationship between the inverter energization current Iinv, the slip determination flag Fs, and the energization time ts in a ROM (not shown) as an energization time setting map. When the determination flag Fs is given, the corresponding energization time ts is derived and set from the stored map. An example of the energization time setting map is shown in FIG. As shown in the figure, the energization time ts tends to be shorter as the inverter energization current Iinv is larger, and is set to be shorter when the slip determination flag Fs is 1 than when it is 0. did. In the embodiment, the decrease rate Rd is preliminarily stored in a ROM (not shown) as a decrease rate setting map in which the relationship between the energization time ts, the inverter energization current Iinv, and the decrease rate Rd is stored. When the energization current Iinv is given, the corresponding decrease rate Rd is derived from the stored map and set. An example of the reduction rate setting map is shown in FIG. As shown in the figure, the decrease rate Rd is set so as to decrease as the inverter energization current Iinv decreases and to decrease as the energization time ts decreases. Since the energization time ts is shorter when the slip determination flag F is the value 1 than when the slip determination flag F is the value 0, the decrease gate Rd determines the slip determination when the slip determination flag F is the value 1. A smaller value is set than when the flag F is 0. Hereinafter, the reason why the energization time ts and the decrease rate Rd are set to such a tendency will be described.

  Now, consider the case where the front wheels 38a and 38b slip and the motor 42 is in the motor lock state. Hereinafter, for convenience of explanation, the driving force due to the grip between the front wheels 38a and 38b and the road surface, and the driving force due to the grip between the rear wheels 48a and 48b and the road surface are respectively referred to as a front wheel side grip driving force Tf and a rear wheel side grip driving force Tr. The sum of the front wheel side grip driving force Tf and the rear wheel side grip driving force Tr may be referred to as the overall grip driving force Tto. When the front wheels 38a and 38b are slipping, it can be considered that the front wheel side grip driving force Tf is substantially zero. FIG. 5 shows an example of the slip determination when the front wheels 38a and 38b slip and the motor 42 is in the motor lock state, and how the front wheel side, the rear wheel side, and the overall grip driving force Tf, Tr, Tto change over time. It is explanatory drawing shown. The left side of the figure shows an embodiment in which the energization time ts and the decrease rate Rd are made smaller than when the front wheels 38a and 38b are not slipping, and the right side of the figure is the same energization as when the front wheels 38a and 38b are not slipping. The state of the comparative example using time ts and decreasing rate Rd is shown. First, in common with the example and the comparative example, the energization time ts (time ts1 in the example, time ts2 (> ts1) in the comparative example) after the front wheels 38a and 38b slip and the motor 42 is in the motor locked state. When the torque of the motor 42 is decreased from the timing when the time elapses, the rear wheel side grip driving force Tr, that is, the total grip driving force Tto decreases, and when the total grip driving force Tto decreases to some extent, the slip of the front wheels 38a and 38b occurs. After that, the rear wheel side grip driving force Tr continuously decreases, and the front wheel side grip driving force Tf increases. At this time, as shown in the comparative example on the right side of the figure, if the reduction rate Rd is large, the rear wheel side grip driving force Tr decreases rapidly, and therefore the entire grip driving is performed after the slip of the front wheels 38a and 38b is eliminated. The force Tto does not increase so much. On the other hand, in the embodiment on the left side in the figure, the reduction rate Rd is small, and the rear wheel side grip driving force Tr gradually decreases, so that the overall grip driving force Tto increases after the slip of the front wheels 38a, 38b is eliminated. As a result, it is possible to improve the climbing performance after the front wheels 38a and 38b slip on the uphill road and the motor 42 enters the motor lock state and the slip is subsequently eliminated. Thus, in order to improve the climbing performance, it is preferable to reduce the descent rate Rd. However, since it is necessary to prevent the motor 42 and the inverter 44 from exceeding their allowable upper limit temperatures, in the embodiment, in order to reduce the descent rate Rd, the value 0 when the slip determination flag F is 1 The energization time ts is set to a smaller value than in the case of This is the reason why the energization time ts and the decrease rate Rd are set to the above-described tendency.

  According to the electronic control unit 70 provided in the hybrid vehicle 20 of the embodiment described above, when the front wheels 38a and 38b are slipping when the motor 42 is in the motor locked state, the front wheels 38a and 38b are slipping. A shorter energization time ts is set and a smaller decrease rate Rd is set as compared to when the motor 42 is not, and the torque of the motor 42 is reduced at the decrease rate Rd from the timing when the energization time ts has elapsed since the motor 42 is determined to be in the motor lock state. Since the motor 42 is controlled so as to decrease, the torque of the motor 42 is reduced to some extent (the overall grip driving force Tto is reduced to some extent), and the overall grip driving force Tto after the slip of the front wheels 38a and 38 is eliminated is further increased. can do. As a result, it is possible to improve the climbing performance after the front wheels 38a and 38b slip on the uphill road and the motor 42 enters the motor lock state and the slip is subsequently eliminated.

  In the hybrid vehicle 20 of the embodiment, the energization time ts and the decrease rate Rd are set based on the inverter energization current Iinv and the slip determination flag Fs, but the energization time ts and the decrease rate based only on the slip determination flag Fs. Rd may be set.

  In the hybrid vehicle 20 of the embodiment, the energization time ts and the decrease rate Rd are set using the inverter energization current Iinv. However, the inverter temperature Tinv from the temperature sensor 45 that detects the element temperature of the inverter 44 and the motor 42 are set. Alternatively, the energization time ts and the decrease rate Rd may be set using the temperature of the cooling water for cooling the inverter 44.

  In the hybrid vehicle 20 of the embodiment, the motor 42 is configured as a synchronous generator motor, but may be configured as an induction motor.

  In the hybrid vehicle 20 of the embodiment, on the front wheels 38a, 38b side, the engine 32 is attached to the drive shaft 36 connected to the front wheels 38a, 38b via the transmission 34, but the hybrid of the modified example of FIG. As shown in an automobile 120, an engine 136 and a transmission 34 are provided with a clutch 133 and a motor 134, and an inverter 136 for driving the motor 134, an inverter 44, and a battery 50 can exchange electric power. The power from the motor 32 may be output to the drive shaft 36 via the rotation shaft of the motor 134 and the transmission 34, and the power from the motor 134 may be output to the drive shaft 36 via the transmission 34.

  In the hybrid vehicle 20 of the embodiment, on the front wheels 38a and 38b side, the engine 32 is attached to the drive shaft 36 connected to the front wheels 38a and 38b via the transmission 34, but the hybrid of the modified example of FIG. As shown in an automobile 220, the carrier and ring gear of the planetary gear 234 are connected to the engine 32 and the drive shaft 36, the motor 235 is connected to the sun gear of the planetary gear 234, the motor 236 is attached to the drive shaft 36, and the motors 235 and 236 are connected. The inverters 237 and 238, the inverter 44, and the battery 50 for driving the power may be exchanged. In this case, even when the rear wheels 48a and 48b slip and the motor 236 is in the motor locked state, it can be considered in the same manner as in the embodiment.

  In the hybrid vehicle 20 of the embodiment, on the front wheels 38a and 38b side, the engine 32 is attached to the drive shaft 36 connected to the front wheels 38a and 38b via the transmission 34. As shown in an automobile 320, a motor 332 may be attached to the drive shaft 36 so that power can be exchanged between the inverter 334 for driving the motor 332, the inverter 44, and the battery 50. In this case, even when the rear wheels 48a and 48b slip and the motor 332 is in the motor lock state, it can be considered in the same manner as in the embodiment.

  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 32 and the transmission 34 correspond to a “power output device”, the motor 42 corresponds to a “motor”, and the front wheels 38a and 38b slip when the motor 42 is in a motor lock state. When the front wheels 38a and 38b are not slipping, the torque-reduction related value setting routine in FIG. 2 for setting a short energization time ts and setting a small decrease rate Rd is executed as compared to when the front wheels 38a and 38b are not slipping. The electronic control unit 70 that controls the motor 42 so as to reduce the torque of the motor 42 at the decrease rate Rd from the timing when the energization time ts has elapsed since the motor 42 is in the motor lock state (from the determination) becomes the “control device”. Equivalent to.

  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 hybrid vehicle, 32 engine, 34 transmission, 36 drive shaft, 37 differential gear, 38a, 38b front wheel, 42 motor, 44 inverter, 45 temperature sensor, 46 drive shaft, 47 differential gear, 48a, 48b rear wheel, 50 battery , 70 Electronic control unit, 80 Ignition switch, 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, 89, 90 Rotational speed sensor.

Claims (1)

A vehicle control device comprising a power output device connected to a first axle and a motor connected to a second axle,
When the first axle side drive wheel, which is the drive wheel to which the first axle is connected, is slipping when the motor is in a motor lock state, the first axle side drive wheel is not slipping. Controlling the motor so that the torque of the motor decreases gradually from an early timing,
The control apparatus of the motor vehicle characterized by the above-mentioned.

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