JP5239809B2 - Vehicle control apparatus and control method - Google Patents

Description

  The present invention relates to control of a vehicle equipped with an internal combustion engine and a motor as drive sources, and more particularly to control of a motor during catalyst warm-up of the internal combustion engine.

  In recent years, a hybrid vehicle equipped with an internal combustion engine and a motor as drive sources has attracted attention as one countermeasure for environmental problems. In such a hybrid vehicle, in order to make the exhaust purification catalyst of the internal combustion engine activated, it is necessary to warm up the exhaust purification catalyst as in the case of a vehicle using only the conventional internal combustion engine as a drive source. As a technique for warming up the exhaust purification catalyst, for example, Japanese Patent Laying-Open No. 2008-179262 (Patent Document 1) discloses a warm-up control device that enables a rapid increase in exhaust temperature even when the battery reaches full charge. Is disclosed. This warm-up control device needs to raise the exhaust temperature of the engine, a generator that generates power using the engine power, a battery that can charge the power of the generator, a transmission that is interposed between the engine and the wheels, and the engine. Warming-up means for performing either one or both of power generation control for increasing the power generation load of the generator and shift control for changing the transmission gear ratio to the speed-increasing side according to the amount of charge of the battery. It is characterized by providing.

According to the warm-up control device disclosed in the above-mentioned publication, it is possible to warm up by increasing the load on the engine not only by increasing the electric load but also by changing the gear ratio. Therefore, even if the battery reaches full charge by selecting warm-up due to an increase in power generation load, warm-up due to change in gear ratio, or both, depending on the battery charge amount, A rapid increase in temperature is possible.
JP 2008-179262 A

  By the way, when the vehicle is decelerated, for example, when the accelerator pedal is released while the hybrid vehicle is running, a deceleration according to the state of the vehicle is realized by regenerative braking using a motor.

  However, depending on the state of charge of the power storage device, the regenerative power that can be accepted is small, so that a braking force that uses the frictional resistance of the internal combustion engine or the like may be generated. In such a case, fuel cut or the like is performed in the internal combustion engine, so that there is a problem that warming up of the exhaust purification catalyst is interrupted. Therefore, an increase in the temperature of the exhaust purification catalyst is suppressed, and the temperature at which the exhaust purification catalyst becomes activated cannot be reached, and exhaust emission may deteriorate.

  In the warm-up control device disclosed in the above-mentioned publication, no consideration is given to deterioration of exhaust emission due to interruption of warm-up of the exhaust purification catalyst when the vehicle is decelerated, and such a problem cannot be solved.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a vehicle control device and a control method that suppress deterioration of exhaust emission when the hybrid vehicle is decelerated.

  A vehicle control apparatus according to a first aspect of the present invention is a vehicle control apparatus that uses a motor and an internal combustion engine as drive sources. The vehicle includes a power storage device that supplies electric power to the motor. This control device includes a warm-up state detection means for detecting that the internal combustion engine is in a catalyst warm-up state, and a required driving force for the vehicle with the forward side of the vehicle as a positive direction and the reverse side as a negative direction. Driving force detecting means for detecting, shift position detecting means for detecting the shift position of the vehicle, the internal combustion engine is in a catalyst warm-up state, the required driving force is a negative value, and the shift When the prohibition condition that the position is a shift position that generates a driving force in the positive direction is satisfied, the generation of negative driving force by the internal combustion engine is prohibited, and the regenerative power within the range allowed by the power storage device is supported. Control means for controlling the motor so that a negative driving force is generated in the vehicle. A vehicle control method according to a fifth invention has the same configuration as the vehicle control device according to the first invention.

  According to the first aspect of the present invention, the catalyst warm-up state is avoided, and the interruption of the catalyst warm-up is avoided by prohibiting the generation of the negative driving force by the internal combustion engine during the deceleration of the vehicle. Therefore, since the exhaust purification catalyst can be quickly activated, deterioration of exhaust emission can be suppressed. Therefore, it is possible to provide a vehicle control device and a control method that suppress deterioration of exhaust emission when the hybrid vehicle is decelerated.

  In the vehicle control device according to the second invention, in addition to the configuration of the first invention, the control means corresponds to the maximum value of the regenerative power within the range allowed by the power storage device when the prohibition condition is satisfied. Means for calculating the minimum value of the driving force by the motor and control the motor so that the minimum value of the driving force by the motor is generated when the required driving force is greater than the minimum value of the driving force by the motor And a motor for controlling the motor such that a negative driving force is generated by the motor corresponding to the required driving force when the required driving force is less than the minimum value of the driving force by the motor. Means. A vehicle control method according to a sixth invention has the same configuration as the vehicle control device according to the second invention.

  According to the second invention, when the required driving force is greater than the minimum value of the driving force by the motor, the power storage device is controlled by controlling the motor so that the minimum value of the driving force of the motor is generated. Can be protected. In addition, when the required driving force is smaller than the minimum driving force by the motor, the vehicle is controlled by controlling the motor so that a negative driving force by the motor corresponding to the required driving force is generated. The driving force required for the above can be realized.

  In addition to the configuration of the first or second invention, the vehicle control device according to the third invention is based on a motor corresponding to the required driving force and the charge amount of the power storage device when the vehicle is decelerated when the prohibition condition is not satisfied. The apparatus further includes means for permitting generation of the negative direction driving force by the internal combustion engine in accordance with the difference from the negative direction driving force. A vehicle control method according to a seventh aspect has the same configuration as the vehicle control apparatus according to the third aspect.

  According to the third invention, when the prohibition condition is not satisfied, the generation of the negative driving force by the internal combustion engine according to the difference between the required driving force and the negative driving amount by the motor corresponding to the charging amount of the power storage device is generated. By permitting, the driving force required for the vehicle can be realized.

  In the vehicle control device according to the fourth invention, in addition to the configuration of any one of the first to third inventions, the vehicle has a generator for generating power using the power of the internal combustion engine, and the power of the internal combustion engine. It further includes a power split mechanism that splits and transmits the motor and the generator, and wheels connected to the motor. A vehicle control method according to an eighth aspect has the same configuration as the vehicle control apparatus according to the fourth aspect.

  According to the fourth aspect of the invention, by applying the present invention to a vehicle having a generator and a power split mechanism, it is possible to avoid interruption of the catalyst warm-up while the vehicle is in the catalyst warm-up state and the vehicle is decelerating. it can. Therefore, deterioration of exhaust emission can be suppressed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  With reference to FIG. 1, a control block diagram of a hybrid vehicle equipped with a vehicle control apparatus according to an embodiment of the present invention will be described.

  The hybrid vehicle includes an internal combustion engine (hereinafter referred to as an engine) 120 as a drive source, a motor generator (MG) 140 that is a rotating electrical machine, and a transmission 202 connected to the engine 120 and the motor generator 140, respectively. In FIG. 1, for convenience of explanation, the motor generator 140 is expressed as a generator 140A and a motor 140B, but the generator 140A functions as a motor or the motor 140B functions as a generator depending on the traveling state of the hybrid vehicle. To do.

  In the present embodiment, engine 120 is described as being a lean burn gasoline engine, but may be a diesel engine.

  In the intake passage 122 of the engine 120, an air cleaner 122A that captures dust of intake air, an air flow meter 122B that detects the amount of air drawn into the engine 120 through the air cleaner 122A, and an amount of air drawn into the engine 120 are adjusted. An electronic throttle 122C having a throttle valve is provided. The electronic throttle 122C is provided with a throttle position sensor 122D. An engine ECU (Electronic Control Unit) 280 receives an intake air amount detected by an air flow meter 122B, an opening degree of an electronic throttle 122C detected by a throttle position sensor 122D, and the like.

  The engine 120 includes a plurality of cylinders and a fuel injection device 130 that supplies fuel to each of the plurality of cylinders. The fuel injection device 130 injects an appropriate amount of fuel to each cylinder at an appropriate time based on a fuel injection control signal from the engine ECU 280.

  Further, in the exhaust passage 124 of the engine 120, a three-way catalytic converter 124B that is an exhaust purification catalyst, an air-fuel ratio sensor 124A that detects an air-fuel ratio (A / F) in exhaust gas introduced into the three-way catalytic converter 124B, and A catalyst temperature sensor 124C for detecting the temperature of the three-way catalyst converter 124B, a silencer 124D, and an oxygen sensor 124E for detecting the oxygen concentration in the exhaust gas discharged from the three-way catalyst converter 124B are provided.

  In the present embodiment, three-way catalytic converter 124B stores nitrogen oxides in the exhaust gas (also referred to as NOx in the following description), and reduces the stored NOx, while hydrocarbons in the exhaust gas. In addition, although it is described that carbon monoxide is oxidized, a catalyst that stores and reduces at least NOx may be used.

  The engine ECU 280 detects the air-fuel ratio of the exhaust gas introduced into the three-way catalytic converter 124B detected by the air-fuel ratio sensor 124A, the temperature of the three-way catalytic converter 124B detected by the catalyst temperature sensor 124C, and the oxygen sensor 124E. Further, the oxygen concentration of the exhaust gas discharged from the three-way catalytic converter 124B is input.

  Air-fuel ratio sensor 124A is a full-range air-fuel ratio sensor (linear air-fuel ratio sensor) that generates an output voltage proportional to the air-fuel ratio of the air-fuel mixture burned by engine 120. In the present embodiment, air-fuel ratio sensor 124 </ b> A has a detection element, and outputs a signal corresponding to the air-fuel ratio of engine 120 by contacting exhaust gas of engine 120 with the detection element.

  The oxygen sensor 124E detects whether the air-fuel ratio of the air-fuel mixture combusted by the engine 120 is rich or lean with respect to the stoichiometric air-fuel ratio. The oxygen sensor 124E outputs a signal indicating whether the air-fuel ratio of the air-fuel mixture burned by the engine 120 is rich or lean with respect to the stoichiometric air-fuel ratio.

  Note that an oxygen sensor may be used instead of the air-fuel ratio sensor 124A, or an air-fuel ratio sensor may be used instead of the oxygen sensor 124E.

  In addition, a signal indicating the engine coolant temperature is input to engine ECU 280 from water temperature detection sensor 360 that detects the temperature of coolant of engine 120. A crank position sensor 380 is provided on the output shaft of the engine 120, and a signal indicating the rotation speed of the output shaft is input from the crank position sensor 380 to the engine ECU 280.

  Transmission 202 includes a reduction gear 180 and a power split mechanism 200. Reducer 180 transmits power generated by engine 120 and motor generator 140 to wheel 160, and transmits driving of wheel 160 to engine 120 and motor generator 140. Power split device 200 is, for example, a planetary gear mechanism, and distributes the power generated by engine 120 to two paths of wheels 160 (ie, motor 140B) and generator 140A. The planetary gear mechanism includes a sun gear, a ring gear, a carrier, and a pinion gear. For example, the sun gear of the planetary gear mechanism is connected to the generator 140A, the carrier is connected to the engine, and the ring gear is connected to the motor 140B. A transmission mechanism may be provided between the ring gear and the motor 140B.

  Hybrid vehicle further includes a traveling battery 220 and an inverter 240. Traveling battery 220 is a power storage device that stores electric power for driving motor generator 140. Note that a capacitor or the like may be used as the power storage device instead of the traveling battery. Inverter 240 performs current control while converting direct current of traveling battery 220 and alternating current of generator 140A and motor 140B.

  Further, the hybrid vehicle further includes a battery control unit (hereinafter referred to as a battery ECU) 260, an engine ECU 280, an MG_ECU 300, and an HV_ECU 320.

  Battery ECU 260 manages and controls the charge / discharge state of battery for traveling 220. Engine ECU 280 controls the operating state of engine 120. MG_ECU 300 controls motor generator 140, battery ECU 260, inverter 240, and the like according to the state of the hybrid vehicle. The HV_ECU 320 controls and controls the battery ECU 260, the engine ECU 280, the MG_ECU 300, and the like so that the hybrid vehicle can operate most efficiently.

  In the present embodiment, converter 242 is provided between battery for traveling 220 and inverter 240. This is because the rated voltage of the traveling battery 220 is lower than the rated voltage of the generator 140A and the motor 140B. Therefore, when power is supplied from the traveling battery 220 to the generator 140A and the motor 140B, the converter 242 boosts the power. This converter 242 has a built-in smoothing capacitor, and when the converter 242 performs a boosting operation, electric charge is stored in this smoothing capacitor.

  In FIG. 1, each ECU is configured separately, but may be configured as an ECU in which two or more ECUs are integrated (for example, as shown by a dotted line in FIG. 1, engine ECU 280 and MG_ECU 300 An example is an ECU integrated with the HV_ECU 320).

  An accelerator pedal 382 is provided at the driver's seat, and the accelerator position sensor 384 detects the amount of depression of the accelerator pedal 382. The accelerator position sensor 384 outputs a signal indicating the depression amount of the accelerator pedal 382 to the HV_ECU 320. The HV_ECU 320 calculates a required driving force for the vehicle corresponding to the depression amount of the accelerator pedal. In the present embodiment, the required driving force is a positive direction on the forward side of the vehicle and a negative direction on the reverse side. The HV_ECU 320 controls the output of the engine 120 or the power generation amount via the generator 140A, the motor 140B, and the engine ECU 280 according to the required driving force corresponding to the depression amount.

  A shift operation device 388 is further provided in the driver's seat. The shift operation device 388 may have a shift lever or may have a switch, and is not particularly limited. The shift position sensor 386 detects the shift position selected by the driver based on the operation state of the shift operation device 388. Shift position sensor 386 outputs a signal indicating the operating state of shift operating device 388 to HV_ECU 320. The HV_ECU 320 controls the engine 120, the generator 140A, and the motor 140B so as to be in a traveling state corresponding to the shift position selected by the driver. In the present embodiment, the shift position includes, for example, a drive (D) position that generates a driving force in the positive direction, a reverse (R) position that generates a driving force in the negative direction, and from the engine 120 and the motor 140B to the wheel 160. It includes a neutral (N) position that interrupts transmission of power and a parking (P) position that corresponds to the parking state of the vehicle. The shift position may include a brake (B) position that increases the degree of generation of engine braking and / or regenerative braking force that acts on the vehicle, or a shift position that corresponds to the manual shift mode. The engine brake is a negative driving force by the engine 120. The regenerative braking force is a driving force in the negative direction by the motor 140B.

  Furthermore, the wheel speed sensor 330 is a sensor that detects the wheel speed of the wheel 160. The wheel speed sensor 330 outputs a signal indicating the wheel speed of the wheel 160 to the HV_320. The HV_ECU 320 calculates the vehicle speed based on the wheel speed. The signal indicating the wheel speed detected by the wheel speed sensor 330 may be transmitted to the HV_ECU 320 via the brake ECU (not shown), or the vehicle speed is calculated by the brake ECU, and the calculated vehicle speed is calculated. A signal indicating the speed may be input to the HV_ECU 320. Further, HV_ECU 320 may calculate the speed of the vehicle based on the rotational speed of the output shaft of transmission 202 instead of the wheel speed.

  The power split mechanism 200 uses a planetary gear mechanism (planetary gear) in order to distribute the power of the engine 120 to both the wheels 160 and the generator 140A. By controlling the rotational speed of generator 140A, power split device 200 also functions as a continuously variable transmission.

  In a hybrid vehicle equipped with a hybrid system as shown in FIG. 1, the hybrid vehicle travels only by the motor 140 </ b> B of the motor generator 140 when the engine 120 is inefficient, such as when starting or running at a low speed. During normal traveling, for example, the power split mechanism 200 divides the power of the engine 120 into two paths, and on the one hand, the wheels 160 are directly driven, and on the other hand, the generator 140A is driven to generate power. At this time, the motor 140B is driven by the generated electric power to assist driving of the wheel 160. Further, at the time of high speed traveling, electric power from the traveling battery 220 is further supplied to the motor 140B to increase the output of the motor 140B to add driving force to the wheels 160.

  On the other hand, at the time of deceleration, the motor 140B driven by the wheel 160 functions as a generator (that is, the motor 140B generates a negative driving force) to perform regenerative power generation, and the recovered electric power is stored in the traveling battery 220. When the amount of charge of traveling battery 220 decreases and charging is particularly necessary, the output of engine 120 is increased to increase the amount of power generated by generator 140A to increase the amount of charge for traveling battery 220. Of course, there is a case where control is performed to increase the driving force of the engine 120 as necessary even during low-speed traveling. For example, it is necessary to charge the traveling battery 220 as described above, to drive an auxiliary machine such as an air conditioner, or to raise the temperature of the cooling water of the engine 120 to a predetermined temperature.

  Furthermore, in a hybrid vehicle equipped with a hybrid system as shown in FIG. 1, engine 120 is stopped in order to improve fuel consumption depending on the driving state of the vehicle and the state of traveling battery 220. And after that, the driving | running state of the vehicle and the state of the battery 220 for a run are detected, and the engine 120 is restarted. In this way, the engine 120 is intermittently operated, and in a conventional vehicle (a vehicle equipped with only an engine), when the ignition switch is turned to the START position and the engine is started, the ignition switch is switched from the ON position to the ACC position. Or it is different in that the engine does not stop until it is in the OFF position. In the hybrid vehicle of the present embodiment, stop of engine 120 is suppressed when the vehicle speed is equal to or higher than a predetermined speed V (0).

  In the vehicle having the above-described configuration, when the temperature of the three-way catalytic converter 124B detected by the catalyst temperature sensor 124C is equal to or lower than a predetermined activation temperature corresponding to the activated state, the three-way catalyst Assuming that converter 124B is in a warm-up incomplete state, warm-up is performed. The three-way catalytic converter 124B is warmed up using exhaust heat generated by continuously operating the engine 120. It should be noted that by increasing the power generation load in generator 140A, the load on engine 120 is increased and the exhaust temperature is raised, so that warm-up of three-way catalytic converter 124B may be promoted, or generator 140A. Thus, the warm-up of the three-way catalytic converter 124B may be promoted by maintaining the rotational speed of the engine 120 at a predetermined rotational speed.

  However, when the regenerative electric power that can be accepted based on the state of charge of the traveling battery 220 is small, if a braking force using the frictional resistance or the like of the engine 120 is generated, a fuel cut or the like is performed in the engine 120. The warm-up of the original catalytic converter 124B may be interrupted. For example, when the battery temperature of the battery for traveling 220 is low, the regenerative power that can be received is smaller than when the battery temperature is high. Alternatively, when the SOC of the traveling battery 220 is high, the regenerative power that can be accepted is smaller than when the SOC is low. If the increase in the temperature of the three-way catalytic converter 124B is suppressed, the predetermined activation temperature cannot be reached and the exhaust emission may be deteriorated.

  Therefore, in the present embodiment, HV_ECU 320 indicates that three-way catalytic converter 124B of engine 120 is in a warm-up state and the driving force required for the vehicle (hereinafter referred to as required driving force) is negative. If the prohibition condition that the shift position is a shift position that generates a driving force in the positive direction is satisfied, the traveling battery 220 is prevented from being generated by the engine 120 while the driving force in the negative direction is prohibited. The motor 140B is controlled such that a negative driving force by the motor 140B corresponding to the regenerative power within the allowable range is generated in the vehicle.

  Specifically, when the prohibition condition is satisfied, the HV_ECU 320 calculates the minimum value of the driving force by the motor 140B corresponding to the maximum value of the regenerative power within the range allowed by the traveling battery 220, and the required driving force When the degree is larger than the minimum value of the driving force by the motor, the motor 140B is controlled so that the minimum value of the driving force by the motor is generated, and the required driving force is greater than the minimum value of the driving force by the motor. If it is smaller, the motor 140B is controlled so that a negative driving force is generated by the motor corresponding to the required driving force.

  When the prohibition condition is not satisfied, the HV_ECU 320 performs a negative direction by the engine 120 according to the difference between the required driving force and the negative driving force by the motor corresponding to the charge amount of the traveling battery 220 when the vehicle decelerates. The generation of driving force is allowed.

  In the present embodiment, it is described that it is determined whether or not the warm-up is completed based on the temperature of the three-way catalytic converter 124B. However, the present invention is not limited to using the temperature as a criterion. Any element that can determine that at least the three-way catalytic converter 124B does not satisfy the predetermined catalytic ability may be used.

  FIG. 2 shows a functional block diagram of HV_ECU 320 which is a vehicle control apparatus according to the present embodiment. The HV_ECU 320 includes a required driving force calculation unit 400, a condition establishment determination unit 402, a minimum driving force calculation unit 404, a driving force determination unit 406, a driving force setting unit 408, a regeneration control unit 410, and a cooperative control unit 412. Including.

  The required driving force calculation unit 400 calculates the required driving force of the vehicle. Specifically, the required driving force calculation unit calculates the required driving force of the vehicle from the depression amount of the accelerator pedal 382 transmitted from the accelerator position sensor 384 and the vehicle speed based on the wheel speed detected by the wheel speed sensor 330. Is calculated. For example, when the accelerator pedal 382 is released (accelerator off), the required driving force calculation unit 400 calculates a negative value as the required driving force value. The required driving force becomes a negative value when the amount of depression of the accelerator pedal 382 is equal to or less than a predetermined value, and becomes a positive value when it is larger than the predetermined value. Further, the required driving force tends to increase as the amount of depression of the accelerator pedal 382 increases. The relationship between the required driving force and the depression amount of the accelerator pedal 382 may be linear or non-linear, and is set in advance using a map, a table, a mathematical expression, or the like and stored in a memory or the like.

  The condition establishment determination unit 402 determines whether the prohibition condition is satisfied. The prohibition condition is that the engine 120 is in the catalyst warm-up state, that is, the three-way catalytic converter 124B of the engine 120 is in the warm-up state, the required driving force of the vehicle is negative, and the shift position is in the positive direction. This is a condition that the shift position generates a driving force of. In the present embodiment, condition establishment determination unit 402 has a three-way catalytic converter 124B having a temperature equal to or lower than a predetermined activation temperature, and the required driving force calculated by required driving force calculation unit 400 is a negative value. If the shift position is the (D) position, it is determined that the prohibition condition is satisfied. The shift position only needs to include at least the (D) position. For example, in addition to the (D) position, the shift position may include a shift position for selecting the manual shift mode, and the degree of engine braking. A shift position (for example, the (B) position described above) set according to the above may be included.

  Note that the condition satisfaction determination unit 402 may turn on the prohibition flag or turn off the permission flag when the prohibition condition is satisfied, for example. For example, the condition establishment determination unit 402 may turn off the prohibition flag or turn on the permission flag when the prohibition condition is not satisfied.

  When the prohibition condition is satisfied, the minimum driving force calculation unit 404 sets the minimum value of the driving force by the motor 140B corresponding to the maximum value of the regenerative power within the allowable range based on the input limit Win to the traveling battery 220 (regeneration). The maximum amount is calculated as the braking force. The relationship between the input limit Win to the traveling battery 220 and the minimum value of the driving force by the motor 140B may be adapted through experiments or the like, and may be set in advance using a map, a table, or a mathematical expression. When receiving the input limit Win of the traveling battery 220 from the battery ECU 260, the minimum driving force calculation unit 404 calculates the minimum value of the driving force by the motor 140B based on the input limit Win. The minimum driving force calculation unit 404 calculates the maximum value of regenerative power within an allowable range based on the input limit Win, and the minimum value of driving force by the motor 140B based on the calculated maximum value of regenerative power. May be calculated, or the minimum value of the driving force by the motor 140B may be directly calculated using a map or the like based on the input limit Win, and the calculation method is not particularly limited. Absent.

  In the present embodiment, battery ECU 260 will be described as setting input limit Win based on temperature of traveling battery 220 or SOC (State Of Charge), but in particular, input limit Win is limited only to temperature and SOC. For example, in addition to the temperature and the SOC, the input limit Win may be set based on the life, the charging state, the charging history, and the like of the traveling battery 220.

  The method for setting the input restriction Win may be a known method, and is not limited to the above-described method. Further, the minimum driving force calculation unit 404 may calculate the minimum value of the driving force by the motor 140B when the prohibition flag is on, for example.

  The driving force determination unit 406 determines whether or not the degree of the required driving force calculated by the required driving force calculation unit 400 is greater than the minimum value of the driving force by the motor 140B calculated by the minimum driving force calculation unit 404. judge. Specifically, the driving force determination unit determines whether or not the absolute value of the required driving force is larger than the absolute value of the minimum value of the driving force by the motor 140B. For example, the driving force determination unit 406 may turn on the driving force determination flag when the absolute value of the required driving force is larger than the absolute value of the minimum value of the driving force by the motor 140B.

  Further, the driving force determination unit 406 determines whether or not the value of the required driving force is smaller than the minimum value of the driving force by the motor 140B, and the value of the required driving force is smaller than the minimum value of the driving force by the motor 140B. Then, the driving force determination flag may be turned on.

  When the driving force determination unit 406 determines that the absolute value of the required driving force is larger than the absolute value of the minimum value of the driving force by the motor 140B, the driving force setting unit 408 sets the minimum value of the driving force by the motor 140B. Set as the driving force determination value. Further, when it is determined that the absolute value of the required driving force is equal to or less than the absolute value of the minimum value of the driving force by the motor 140B, the driving force setting unit 408 sets the required driving force as the driving force determination value. Note that the driving force setting unit 408 sets, for example, the minimum value of the driving force by the motor 140B as the driving force determination value when the driving force determination flag is on, and the required driving force when the driving force determination flag is off. You may make it set as a driving force determination value.

  Regenerative control unit 410 generates a motor control signal so that a driving force (braking force) corresponding to the set driving force determination value is expressed, and transmits the motor control signal to MG_ECU 300 to control motor 140B. Regeneration control unit 410 prohibits generation of a negative driving force by increasing the number of revolutions of engine 120 using generator 140A. In addition, regeneration control unit 410 uses generator 140A to maintain the rotational speed of engine 120 at the rotational speed at which three-way catalytic converter 124B is warmed up.

  When the prohibition condition is not satisfied, the cooperative control unit 412 permits the engine 120 to generate a negative driving force, so that the required driving force calculated by the required driving force calculation unit 400 is expressed. A generator control signal and an engine control signal are generated. Cooperation control unit 412 transmits a motor control signal and a generator control signal to MG_ECU 300 to control generator 140A and motor 140B, and transmits an engine control signal to engine ECU 280 to control engine 120.

  In the present embodiment, the requested driving force calculation unit 400, the condition establishment determination unit 402, the minimum driving force calculation unit 404, the driving force determination unit 406, the driving force setting unit 408, the regeneration control unit 410, and the cooperation The control unit 412 is described as functioning as software realized by the CPU of the HV_ECU 320 executing a program stored in the memory, but may be realized by hardware. Such a program is recorded on a storage medium and mounted on the vehicle.

  With reference to FIG. 3, a control structure of a program executed by HV_ECU 320 which is the vehicle control apparatus according to the present embodiment will be described.

  In step (hereinafter, step is described as S) 100, HV_ECU 320 calculates the required driving force.

  In S102, HV_ECU 320 determines whether the prohibition condition is satisfied. Since the prohibition condition is as described above, detailed description thereof will not be repeated. If the prohibition condition is satisfied (YES in S102), the process proceeds to S104. If not (NO in S102), the process proceeds to S116.

  In S104, HV_ECU 320 prohibits generation of negative direction driving force by engine 120. In S106, HV_ECU 320 calculates the minimum value of the driving force by motor 140B based on input limit Win of battery for traveling 220.

  In S108, HV_ECU 320 determines whether the absolute value of the requested driving force is larger than the absolute value of the minimum driving force by motor 140B. If the absolute value of the required driving force is larger than the absolute value of the minimum driving force by motor 140B (YES in S108), the process proceeds to S110. If not (NO in S108), the process proceeds to S112.

  In S110, HV_ECU 320 sets the minimum value of the driving force by motor 140B as the driving force determination value. In S112, HV_ECU 320 sets the requested driving force as a driving force determination value.

  In S114, HV_ECU 320 executes regenerative control, that is, controls motor 140B and realizes three-way catalytic converter 124B so that the driving force (braking force) corresponding to the set driving force determination value is realized. Continue to warm up.

  At S116, HV_ECU 320 permits generation of a driving force in the negative direction by engine 120. In S118, HV_ECU 320 executes driving force control, controls generator 140A and motor 140B via MG_ECU 300 so that the calculated required driving force is realized, and controls engine 120 via engine ECU 280. Control.

  The operation of HV_ECU 320, which is the vehicle control apparatus according to the present embodiment, will be described with reference to FIG.

  For example, it is assumed that the temperature of the three-way catalytic converter 124B is lower than a predetermined activation temperature. At this time, when engine 120 is operating, three-way catalytic converter 124B is warmed up. At this time, the required driving force is calculated based on the depression amount of the accelerator pedal 382 and the speed of the vehicle (S100). Since the three-way catalytic converter 124B has not yet been warmed up, the calculated required driving force becomes a negative value when the driver releases the accelerator pedal 382 while the vehicle is running. In addition, when the shift position is a shift position that generates a driving force in the positive direction, such as the D position, a prohibition condition is satisfied (YES in S102). Therefore, the generation of negative driving force by the engine 120 is prohibited (S104), and the minimum value of the driving force by the motor 140B is calculated based on the input limit Win to the traveling battery 220 (S106). If the absolute value of the required driving force is larger than the absolute value of the minimum driving force by motor 140B (YES in S108), the minimum driving force by motor 140B is set as the driving force determination value (S110). While continuing to warm up the original catalytic converter 124B, the motor 140B is controlled such that a driving force (braking force) corresponding to the set driving force determination value is developed (S114).

  On the other hand, when the absolute value of the required driving force is equal to or smaller than the absolute value of the minimum driving force by motor 140B (NO in S108), the required driving force is set as the driving force determination value (S112), and the three-way catalytic converter is set. The motor 140B is controlled so as to develop a driving force (braking force) corresponding to the set driving force determination value while continuing the warm-up of 124B (S114).

  When the temperature of the three-way catalytic converter 124B becomes equal to or higher than a predetermined activation temperature at time T (0), the warm-up of the three-way catalytic converter 124B is completed. Therefore, since the prohibition condition is not satisfied (NO in S102), generation of negative direction driving force by engine 120 is permitted (S116), and generator 140A, motor 140B and engine 120 are controlled so that the required driving force is expressed. Is done. At this time, when the required driving force is insufficient only by the driving force in the negative direction due to regeneration of electric power to battery for traveling 220, generator 140A is controlled to transmit the fuel cut and power from wheel 160 to engine 120. Thus, in the vehicle, a negative driving force by the engine 120 is generated in addition to a negative driving force by the motor 140B.

  As described above, according to the control apparatus for a vehicle according to the present embodiment, the catalyst is warmed up by prohibiting the generation of a negative driving force by the engine during deceleration of the vehicle. Interruption is avoided. Therefore, since the exhaust purification catalyst can be quickly activated, deterioration of exhaust emission can be suppressed. Therefore, it is possible to provide a vehicle control device and a control method that suppress deterioration of exhaust emission when the hybrid vehicle is decelerated.

  Further, when the absolute value of the required driving force is larger than the minimum value of the driving force by the motor, the battery for traveling can be protected by controlling the motor so that the minimum value of the driving force by the motor is generated. it can. In addition, when the absolute value of the required driving force is smaller than the absolute value of the minimum value of the driving force by the motor, the motor is controlled so that the negative driving force by the motor corresponding to the required driving force is generated. The driving force required for the vehicle can be realized.

  Furthermore, when the prohibition condition is not satisfied, by permitting the generation of the negative driving force by the engine according to the difference between the required driving force and the negative driving force by the motor corresponding to the charge amount of the traveling battery, A driving force (braking force) required for the vehicle can be realized.

  In addition, when the warm-up of the three-way catalytic converter is completed, when the required driving force and the driving force determination value immediately before the warm-up are deviated by a predetermined value or more, a transition state is provided, The driving force determination value may be set so as to gradually change to the required driving force, and the generator 140A, the motor 140B, and the engine 120 may be controlled so as to become the set driving force determination value.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a control block diagram which shows the structure of the hybrid vehicle in this Embodiment. It is a functional block diagram of HV_ECU which is a vehicle control apparatus according to the present embodiment. It is a flowchart which shows the control structure of the program performed with HV_ECU which is a control apparatus of the vehicle which concerns on this Embodiment. It is a timing chart which shows operation | movement of HV_ECU which is the control apparatus of the vehicle which concerns on this Embodiment.

Explanation of symbols

  120 engine, 122 intake passage, 122A air cleaner, 122B air flow meter, 122C electronic throttle, 122D throttle position sensor, 124 exhaust passage, 124A air-fuel ratio sensor, 124B three-way catalytic converter, 124C catalyst temperature sensor, 124D silencer, 124E oxygen sensor , 130 Fuel injection device, 140 Motor generator, 140A generator, 140B motor, 160 wheels, 180 reducer, 200 power split mechanism, 202 transmission, 220 battery for running, 240 inverter, 242 converter, 260 battery ECU, 280 engine ECU, 300 MG_ECU, 320 HV_ECU, 330 Wheel speed sensor, 360 Water temperature detection sensor, 380 Crank position Sensor, 382 accelerator pedal, 384 accelerator position sensor, 386 shift position sensor, 388 shift operation device, 400 required driving force calculation unit, 402 condition establishment determination unit, 404 maximum regenerative braking force calculation unit, 406 driving force determination unit, 408 drive Force setting unit, 410 regeneration control unit, 412 cooperative control unit.

Claims (8)

A control device for a vehicle using a motor and an internal combustion engine as drive sources, the vehicle including a power storage device that supplies electric power to the motor,
A warm-up state detecting means for detecting that the internal combustion engine is in a catalyst warm-up state;
Driving force detection means for detecting a required driving force for the vehicle, wherein the forward side of the vehicle is a positive direction and the reverse side is a negative direction;
Shift position detecting means for detecting the shift position of the vehicle;
When the internal combustion engine is in the catalyst warm-up state, the required driving force is a negative value, and the prohibition condition is satisfied that the shift position is a shift position that generates a positive driving force The motor is configured so that negative driving force by the motor corresponding to regenerative power within a range allowed by the power storage device is generated in the vehicle while prohibiting generation of negative driving force by the internal combustion engine. And a control device for controlling the vehicle. The control means includes
Means for calculating a minimum value of the driving force by the motor corresponding to a maximum value of regenerative power within a range allowed by the power storage device when the prohibition condition is satisfied;
Means for controlling the motor such that the minimum value of the driving force by the motor is generated when the required driving force is greater than the minimum value of the driving force by the motor;
Means for controlling the motor such that a negative driving force by the motor corresponding to the required driving force is generated when the required driving force is smaller than the minimum value of the driving force by the motor. The vehicle control device according to claim 1, comprising:   The control device, when the prohibition condition is not satisfied, during the deceleration of the vehicle, the internal combustion engine according to a difference between the required driving force and a negative driving force by the motor corresponding to a charge amount of the power storage device The vehicle control device according to claim 1, further comprising means for permitting generation of a negative direction driving force by the vehicle. The vehicle includes a generator that generates electric power using the power of the internal combustion engine, a power split mechanism that splits and transmits the power of the internal combustion engine to the motor and the generator, and wheels connected to the motor. In addition seen including,
The vehicle control device according to claim 1, wherein the control unit prohibits generation of a negative driving force by the internal combustion engine using the generator . A method for controlling a vehicle using a motor and an internal combustion engine as driving sources, the vehicle including a power storage device that supplies electric power to the motor,
Detecting that the internal combustion engine is in a catalyst warm-up state;
Detecting a required driving force for the vehicle, wherein the forward side of the vehicle is a positive direction and the reverse side is a negative direction;
Detecting a shift position of the vehicle;
When the internal combustion engine is in the catalyst warm-up state, the required driving force is a negative value, and the prohibition condition is satisfied that the shift position is a shift position that generates a positive driving force The motor is configured so that negative driving force by the motor corresponding to regenerative power within a range allowed by the power storage device is generated in the vehicle while prohibiting generation of negative driving force by the internal combustion engine. And a step of controlling the vehicle. The step of controlling the motor comprises
When the prohibition condition is satisfied, calculating a minimum value of the driving force by the motor corresponding to a maximum value of regenerative power within a range allowed by the power storage device;
Controlling the motor such that a minimum value of the driving force by the motor is generated when the required driving force is greater than the minimum value of the driving force by the motor;
Controlling the motor such that a negative driving force by the motor corresponding to the required driving force is generated when the required driving force is smaller than the minimum driving force by the motor. The vehicle control method according to claim 5, further comprising:   In the control method, when the prohibition condition is not satisfied, the internal combustion engine according to a difference between the required driving force and a negative driving force by the motor corresponding to a charge amount of the power storage device when the vehicle decelerates The vehicle control method according to claim 5, further comprising a step of permitting generation of a driving force in the negative direction by the control. The vehicle includes a generator that generates electric power using the power of the internal combustion engine, a power split mechanism that splits and transmits the power of the internal combustion engine to the motor and the generator, and wheels connected to the motor. In addition seen including,
The vehicle control method according to claim 5, wherein the control method further includes a step of prohibiting generation of a negative driving force by the internal combustion engine using the generator .

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