JP2011161991A - Controller for on-vehicle power generation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that when the target value (target rotating speed) of an engine rotating speed exceeds its upper limit value (upper limit rotating speed) due to the occurrence of the slip of a driving wheel, the target rotating speed being limited to an upper limit rotating speed or less results in the sharp decrease of the upper limit rotating speed, and the sharp increase of the generated power of an MG1 results in the deterioration of the reliability of a battery or the like. <P>SOLUTION: When it is determined that the logical product of conditions that the changing speed of the actual rotating speed of a driving wheel 14 becomes less than a specific speed as a negative value and conditions that the target rotating speed exceeds the specific rotating speed is true, it is predicted that the generated power of an MG1 rapidly increases. Then, in a period when it is predicted that the generated power of the MG1 rapidly increases, the target rotating speed is limited to the lower rotation side of an upper limit rotating speed based on the actual rotating speed of the driving wheel 14. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is a power transmission mechanism that enables power transmission between an output shaft of an internal combustion engine, a rotating shaft of a rotating electrical machine, and a driving shaft capable of transmitting power to the driving wheel, and the output shaft, the rotating shaft, and the driving shaft. A power transmission mechanism for aligning rotational speeds of the first rotating body, the second rotating body, and the third rotating body that are mechanically coupled to each of the first rotating body and the third rotating body on a collinear diagram, This is applied to a vehicle including power storage means capable of storing generated power, and the upper limit value of the rotation speed of the output shaft is set to a larger value as the rotation speed of the third rotating body is higher. The rotation speed of the output shaft It is related with the control apparatus of the vehicle-mounted motive power generator which operates the said rotary electric machine to restrict | limit to below the said upper limit.

  As this type of control device, as can be seen in Patent Document 1 below, a planetary gear mechanism is provided as a power transmission mechanism, and an output shaft of an internal combustion engine, a rotary shaft of a rotating electrical machine are provided for each of the carrier, sun gear and ring gear. In addition, a control device for a vehicle in which each of the drive shafts is mechanically connected is also proposed. In this control device, the rotation speed of the output shaft is controlled to be equal to or lower than the upper limit value so that the rotation speed of the output shaft of the internal combustion engine and the rotation shaft of the rotating electrical machine do not become excessively high. Specifically, considering that the rotational speeds of the carrier, sun gear, and ring gear are aligned on a straight line on the collinear chart, the upper limit value is set to a larger value as the rotational speed of the ring gear (drive shaft) is higher. Yes. Thereby, it becomes possible to suppress appropriately the fall of reliability, such as an internal combustion engine and a rotary electric machine. In addition, as a technique for suppressing a decrease in reliability of a rotating electrical machine or the like, there is one described in Patent Document 2 below.

JP 2008-247205 A JP 2008-149742 A

  However, according to the technique described in Patent Document 1, although it is possible to suppress a decrease in the reliability of a rotating electrical machine or the like, there is a risk that the reliability of the power storage means may be decreased due to a sudden decrease in the upper limit value. . In other words, the higher the rotation speed of the ring gear, the higher the upper limit value is set. Therefore, after the slip of the drive wheel, the slip is eliminated (grip), so that the ring gear is mechanically connected. When the rotational speed of the drive shaft decreases rapidly, the upper limit value decreases rapidly, and the rotational speed of the output shaft may exceed the upper limit value. In this case, the rotational speed of the output shaft is rapidly reduced by operating the rotating electrical machine to limit the rotational speed of the output shaft to the upper limit value or less. Here, the reduction in the rotation speed of the output shaft is realized by converting the rotation energy of the output shaft into the power generation energy of the rotating electrical machine. For this reason, in order to rapidly reduce the rotation speed of the output shaft, the electric power generated by the rotating electrical machine increases rapidly, and there is a risk that the reliability of the power storage means decreases due to excessive power being supplied to the power storage means.

  The present invention has been made to solve the above-described problem, and its object is to generate on-vehicle power that can suppress the occurrence of a situation in which the reliability of the power storage means decreases due to the sudden decrease in the upper limit value. It is to provide a control device for the apparatus.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

  The invention described in claim 1 is a power transmission mechanism that enables power transmission between an output shaft of an internal combustion engine, a rotary shaft of a rotating electrical machine, and a drive shaft capable of power transmission with the output shaft, A power transmission mechanism for aligning rotational speeds of the first rotating body, the second rotating body, and the third rotating body mechanically connected to each of the shaft and the drive shaft on a collinear diagram on a straight line; The present invention is applied to a vehicle provided with power storage means capable of storing electric power generated by the rotating electrical machine, and sets the upper limit value of the rotational speed of the output shaft to a larger value as the rotational speed of the third rotating body is higher. In a control device for an in-vehicle power generation device that operates the rotating electrical machine to limit the rotation speed of the shaft to the upper limit value or less, a sudden increase in the generated power is predicted based on a decrease speed of the rotation speed of the third rotating body And when the generated power suddenly increases Based to be measured, characterized in that it comprises a limiting means for limiting said third rotational speed of the output shaft to the low rotation side than the upper limit value corresponding to the rotational speed of the rotating body.

  If the reduction speed of the rotation speed of the third rotating body is high, the reduction speed of the upper limit value becomes high, and then the rotation speed of the output shaft becomes equal to or higher than the upper limit value. It becomes easy to increase rapidly. For this reason, the decrease rate of the rotation speed of the third rotating body is a parameter for predicting a sudden increase in the generated power of the rotating electrical machine. In view of this point, in the above invention, it is possible to predict a sudden increase in the generated electric power of the rotating electrical machine based on the decreasing speed of the rotating speed of the third rotating body. Then, based on the fact that the generated power is predicted to increase rapidly, the rotational speed of the output shaft is limited in the above manner. Thereby, it is possible to appropriately suppress the sudden increase in the generated electric power of the rotating electrical machine due to the sudden decrease in the upper limit value, and thus it is possible to suppress the occurrence of inconvenience such as a decrease in the reliability of the power storage means.

  According to a second aspect of the present invention, in the first aspect of the present invention, the conversion means for converting the traveling speed of the vehicle into the rotational speed of the third rotating body, and the converted rotational speed as the third rotating body. And calculating means for calculating the upper limit value when the actual rotation speed is assumed, and the prediction means has an actual rotation speed of the output shaft higher than the upper limit value calculated by the calculation means. On the basis of this, a sudden increase in the generated power is predicted.

  Even when the actual rotational speed of the third rotating body changes suddenly, the rotational speed of the third rotating body (assumed rotational speed of the rotating body) converted from the traveling speed of the vehicle does not change suddenly. For this reason, the upper limit of the rotation speed of the output shaft (assumed upper limit speed of the output shaft) when the assumed rotation speed of the rotation body is assumed to be the actual rotation speed of the third rotation body does not change suddenly. Therefore, according to the actual rotational speed of the output shaft and the assumed upper limit speed of the output shaft, whether or not the generated power increases rapidly due to the rotational speed of the output shaft being limited by the upper limit value. It becomes possible to grasp in advance. In view of this point, in the above invention, it is possible to more appropriately predict a sudden increase in the generated electric power of the rotating electrical machine based on the fact that the actual rotational speed of the output shaft becomes higher than the assumed upper limit speed of the output shaft.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the limiting means limits the rotational speed of the output shaft according to a decrease in the rotational speed of the third rotating body. And

  In the above invention, since the rotation speed of the output shaft is limited according to the decrease in the rotation speed of the third rotating body used for setting the upper limit value, the rotation speed of the output shaft is not limited by the upper limit value. The rotational speed of the output shaft can be appropriately limited according to the sudden decrease in the upper limit value.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects of the present invention, in the process of limiting the rotation speed of the output shaft, the limiting means supplies fuel to the internal combustion engine. It is characterized by performing a process of stopping.

  In the above invention, since the torque generation of the internal combustion engine is stopped in the process of limiting the rotation speed of the output shaft, the electric power generated by the rotary electric machine accompanying the limitation of the rotation speed of the output shaft by the rotary electric machine can be reduced. .

  The invention according to claim 5 is a power transmission mechanism that enables power transmission between the output shaft of the internal combustion engine, the rotary shaft of the rotating electrical machine, and the drive shaft capable of power transmission with the output shaft, the rotation shaft. A power transmission mechanism for aligning rotational speeds of the first rotating body, the second rotating body, and the third rotating body mechanically connected to each of the shaft and the drive shaft on a collinear diagram on a straight line; The present invention is applied to a vehicle provided with power storage means capable of storing electric power generated by the rotating electrical machine, and sets the upper limit value of the rotational speed of the output shaft to a larger value as the rotational speed of the third rotating body is higher. In the control device for the on-vehicle power generation device that operates the rotating electrical machine to limit the rotational speed of the shaft to the upper limit value or less, the vehicle further includes means for converting the traveling speed of the vehicle into the rotational speed of the third rotating body. The upper limit value is the converted third rotation. Characterized in that it is based on the rotational speed setting.

  Even when the actual rotational speed of the third rotator suddenly changes due to the occurrence of slippage of the drive wheels, the rotational speed of the third rotator converted from the traveling speed of the vehicle (assumed rotational speed of the rotator) ) Does not change suddenly. In view of this point, in the above invention, by setting the upper limit value based on the assumed rotation speed of the rotating body, even if the actual rotation speed of the third rotating body is rapidly decreased, the upper limit value is rapidly decreased. Can be avoided. As a result, it is possible to suppress a sudden increase in the generated electric power of the rotating electrical machine due to a sudden decrease in the upper limit value, and thus it is possible to suppress the occurrence of a situation where the reliability of the power storage means is lowered.

  The invention according to claim 6 is a power transmission mechanism that enables power transmission between the output shaft of the internal combustion engine, the rotary shaft of the rotating electrical machine, and the drive shaft capable of transmitting power to the drive wheel. A power transmission mechanism for aligning rotational speeds of the first rotating body, the second rotating body, and the third rotating body mechanically connected to each of the shaft and the drive shaft on a collinear diagram on a straight line; The present invention is applied to a vehicle provided with power storage means capable of storing electric power generated by the rotating electrical machine, and sets the upper limit value of the rotational speed of the output shaft to a larger value as the rotational speed of the third rotating body is higher. In the control device of the on-vehicle power generation device that operates the rotating electrical machine to limit the rotation speed of the shaft to the upper limit value or less, when the decrease speed of the rotation speed of the third rotating body is high, the rotation speed of the output shaft A means to relax the upper limit of the rate of decrease of And wherein the Rukoto.

  For the purpose of avoiding a decrease in drivability, reliability of the power storage means, etc., a process is usually performed to limit the upper limit of the reduction speed so that the reduction speed of the rotation speed of the output shaft does not become excessively high. . However, when the reduction speed is limited, the rotation speed of the output shaft is difficult to decrease even under conditions where the upper limit value suddenly decreases. There is a risk that the value may be forcibly reduced as the value rapidly decreases. In this regard, in the above-described invention, when the decrease rate of the rotation speed of the third rotating body is high, the restriction on the upper limit side of the decrease rate is relaxed. As a result, the rotational speed of the output shaft can be prevented from colliding with the upper limit value by lowering the rotational speed of the output shaft in advance, although it is slower than the decreasing speed of the upper limit value. Can be suppressed. Therefore, it is possible to suppress the occurrence of a situation where the reliability of the power storage means is reduced.

1 is a system configuration diagram according to a first embodiment. FIG. The collinear diagram which shows the outline | summary of the overspeed prevention control concerning the embodiment. The flowchart which shows the procedure of the prediction process and reduction process concerning the embodiment. The figure which shows the outline | summary of the prediction process concerning the embodiment. The figure which shows the outline | summary of the pull-down process concerning the embodiment. The figure which shows the outline | summary of the pull-down process concerning the embodiment. The time chart which shows the prediction process and reduction process concerning the embodiment. The time chart which shows the over-rotation prevention control process concerning 2nd Embodiment. The figure which shows the outline | summary of the limit value relaxation process concerning 3rd Embodiment. 6 is a flowchart showing a procedure of limit value relaxation processing according to the embodiment.

(First embodiment)
Hereinafter, a first embodiment in which a control device according to the present invention is applied to a vehicle (hybrid vehicle) including an engine and a rotating electrical machine as an in-vehicle power generation device will be described with reference to the drawings.

  FIG. 1 shows a system configuration diagram according to the present embodiment.

  As shown in the figure, the hybrid vehicle includes an engine 10, a first motor generator 11a (hereinafter referred to as MG1) and a second motor generator 11b (hereinafter referred to as MG2), which are generators and electric motors, and a power split mechanism 12. And various control devices. The MG 2 is mechanically coupled to the drive shaft 14 and can transmit power to the drive wheels 18 (for example, the rear wheels of the vehicle) via the drive shaft 14 and the differential gear 16. It has a function as a device.

  Each cylinder of the engine 10 is provided with a fuel injection valve 19 for supplying fuel to the combustion chamber of the engine 10. The energy generated by the combustion of the mixture of fuel and intake air supplied by the fuel injection valve 19 is extracted as rotational energy of the output shaft (crankshaft 20) of the engine 10. A crank angle sensor 22 that detects the rotation angle of the crankshaft 20 is provided near the crankshaft 20.

  The power split mechanism 12 enables power transmission between the engine 10, the MG 1, and the drive shaft 14. Specifically, the power split mechanism 12 includes a sun gear S, a ring gear R, a plurality of pinion gears P (two illustrated in the figure) that enable power transmission between the sun gear S and the ring gear R, and a carrier C. Is a planetary gear mechanism configured to include: Here, the crankshaft 20 is mechanically connected to the carrier C, and the drive shaft 14 is mechanically connected to the ring gear R. The sun gear S is mechanically connected to the rotation shaft of MG1. In particular, in the present embodiment, the crankshaft 20 and the carrier C rotate at the same rotational speed, the rotational shaft of the MG1 and the sun gear S rotate at the same rotational speed, and further, the rotational shaft and the ring gear of the drive shaft 14 and MG2. R rotates at the same rotation speed. Further, these rotational speeds are arranged in a straight line on the alignment chart in the order of the rotational speeds of the rotation shaft of MG1, the crankshaft 20, and the drive shaft 14.

  The MG 1 has a function of a generator using the engine 10 as a power supply source and an electric motor for applying initial rotation to the crankshaft 20 when the engine 10 is started. Specifically, when MG1 functions as a generator, the power input from the crankshaft 20 to the carrier C is divided to be input to the sun gear S and the ring gear R, and the power input to the sun gear S is divided. It becomes a drive source of MG1. On the other hand, when MG1 functions as an electric motor, the power input from MG1 to sun gear S is input to crankshaft 20 via carrier C, whereby the initial rotation is applied.

  Each of the MG1 and MG2 exchanges power with the battery 23 via a power control unit (hereinafter referred to as PCU). The PCU includes an inverter (INV1, INV2) for driving and controlling each of the MG1 and MG2, a converter (CONV), a motor electronic control device (hereinafter referred to as a motor ECU 24), and the like.

  The motor ECU 24 is a control device that operates various devices in the PCU including the inverter necessary for driving control of the MG1 and MG2. To the motor ECU 24, detection signals such as a rotational position detection sensor (not shown) for detecting the rotational positions of the MG1 and MG2 rotors are sequentially input. Then, by controlling an inverter or the like based on these input signals, the torque and the like of MG1 and MG2 are controlled. Here, between the MG1 and MG2, the electric power generated by one of these motors can be consumed by the other. In such a configuration, it is possible to control the battery 23 to be charged by the electric power generated by one of the MG1 and MG2 or to discharge the insufficient electric power from the battery 23 by any of these motors. In addition, when one generated electric power between MG1 and MG2 and the other power consumption become the same, the battery 23 will not be charged / discharged.

  The battery electronic control device (hereinafter referred to as the battery ECU 26) is a control device that manages the storage amount (SOC) of the battery 23 and the like. The battery ECU 26 sequentially inputs detection signals such as a voltage sensor (not shown) that detects the voltage of the battery 23, and based on these input signals, the amount of stored electricity and the maximum to the battery 23 that can maintain the reliability of the battery 23 during charging. The supply power (maximum charge power Win), the maximum discharge power (maximum discharge power Wout) from the battery 23 that can maintain the reliability of the battery 23 during discharge, and the like are managed.

  The engine electronic control device (hereinafter, engine ECU 28) is a control device that operates various actuators necessary for combustion control of the engine 10 and the like. The engine ECU 28 sequentially receives detection signals from the crank angle sensor 22 and performs fuel injection control by the fuel injection valve 19 based on these input signals.

  The hybrid electronic control device (hereinafter referred to as HV-ECU 30) is a control device that operates the engine 10, MG1, MG2, and the like via the motor ECU 24, the engine ECU 28, and the like in order to perform drive control and the like of the vehicle. The HV-ECU 30 includes various control signals from the motor ECU 24, the battery ECU 26, and the engine ECU 28, a wheel speed sensor 32 provided in the vicinity of a driven wheel (for example, the front wheel of the vehicle) to detect the traveling speed of the vehicle, and the accelerator operation amount of the driver. The detection signals of the accelerator sensor 33 for detecting the rotation and the rotation speed sensor 34 for detecting the rotation speed of the drive shaft 14 are sequentially input. Based on these input signals, the engine ECU 28 and the motor ECU 24 are operated in order to realize torque required for output to the drive shaft 14 (vehicle required torque) and power required for the engine 10 (engine required power). Thus, the engine rotation speed based on the output value of the crank angle sensor 22 is controlled to the target value (target rotation speed), or torque control of MG1 and MG2 is performed. Here, the calculation process of the target rotation speed (target rotation speed calculation process) will be described. First, from the travel speed of the vehicle based on the output value of the wheel speed sensor 32 and the accelerator operation amount based on the output value of the accelerator sensor 33, Calculate the required vehicle torque. Here, the vehicle required torque is set to be larger as the accelerator operation amount is larger, and is set to be smaller as the vehicle traveling speed is higher. For example, the vehicle required torque associated with the accelerator operation amount and the vehicle traveling speed is defined. It is calculated using a map or the like. Next, the engine required power is calculated from a product value of the calculated vehicle required torque and the rotational speed of the drive shaft 14 based on the output value of the rotational speed sensor 34 or the like. Here, the engine required power is set to be larger as the multiplication value is larger. Then, the target rotational speed is calculated based on the calculated required engine power. Specifically, a map determined in advance through experiments or the like in which the generated torque of the engine 10 associated with the engine rotation speed is defined in order to efficiently operate the engine 10 is used. The engine rotation speed when the product torque multiplied by 10 is equal to the engine required power is calculated as the target rotation speed. For this reason, when the vehicle required torque increases or the rotational speed of the drive shaft 14 increases, the target rotational speed is set high by increasing the engine required power.

In particular, for the purpose of avoiding a decrease in the reliability of the MG1 and the pinion gear P, the HV-ECU 30 exceeds the upper limit value (upper limit rotation speed Nlimit) for the purpose of avoiding a decrease in reliability of the MG1 and the pinion gear P. Over-rotation prevention control, which is control for limiting the target rotational speed Netgt to the upper limit rotational speed Nlimit or less, is performed. This control will be explained. First, in view of the fact that the rotational speeds of the sun gear S, the carrier C, and the ring gear R are aligned on a collinear chart, the upper limit value of the engine rotational speed that can maintain the reliability of the MG1 (MG1 upper limit rotation speed Nemax1) is calculated by the following equation (1).
Nemax1 = ρ / (1 + ρ) × Ngmax + 1 / (1 + ρ) × Np (1)
Ρ: Ratio of the number of teeth of the sun gear S to the number of teeth of the ring gear R Ngmax [rpm]: Upper limit value of the rotational speed of the rotating shaft of MG1 capable of maintaining the reliability of MG1 Np [rpm]: Drive shaft 14 Actual rotation speed (hereinafter, actual rotation speed of the drive shaft 14)

On the other hand, the upper limit value (pinion upper limit rotation speed Nemax2) of the engine rotation speed that can maintain the reliability of the pinion gear P is calculated by the following expression (2).
Nemax2 = Np + γ × Npinmax (2)
Γ: Ratio of the number of teeth of the pinion gear P to the number of teeth of the ring gear R Npinmax [rpm]: Upper limit value of the rotational speed of the pinion gear P that can maintain the reliability of the pinion gear P

Next, the MG1 upper limit rotation speed Nemax1 and the pinion upper limit rotation speed Nemax2 calculated by the above formulas (1) and (2), and the upper limit value of the engine rotation speed that can maintain the reliability of the engine 10 (engine upper limit rotation speed Nemax3). ) Is calculated as the upper limit rotation speed Nlimit. That is, the upper limit rotation speed Nlimit is calculated by the following equation (3).
Nlimit = min (Nemax1, Nemax2, Nemax3) (3)

  In the present embodiment, when the actual rotation speed Np of the drive shaft 14 is in the low-speed rotation range, the medium-speed rotation range, and the high-speed rotation range, the upper limit rotation speed Nlimit is MG1 upper limit rotation speed Nemax1 and pinion upper limit rotation. The upper limit value Ngmax of the rotational speed of the rotating shaft of the MG1, the upper limit value Npinmax of the rotational speed of the pinion gear P, the engine upper limit rotational speed Nemax3 and the ratio of the number of teeth (ρ , Γ) is set. For this reason, when the actual rotation speed Np of the drive shaft 14 is in the low speed rotation range or the medium speed rotation range, the upper limit rotation speed Nlimit is proportional to the actual rotation speed Np of the drive shaft 14.

  According to the over-rotation prevention control, as shown in FIG. 2, the target rotational speed Netgt (the rotational speed of the carrier C in the figure) is limited by the upper limit rotational speed Nlimit, whereby the rotational speed of the rotary shaft of the MG1 (FIG. Among them, the rotation speed of the sun gear S) can be made equal to or lower than the upper limit value Ngmax of the rotation speed of the rotation shaft of the MG1, and it becomes possible to avoid a decrease in reliability of the MG1 and the like.

  By the way, although it is possible to avoid a decrease in reliability of MG1 and the like by the over-rotation prevention control, due to the reason that the target rotation speed Netgt is limited by the upper limit rotation speed Nlimit by this control, for the reason described below. There is a risk that the reliability of the PCU and the battery 23 may be reduced.

  When the drive wheel 18 slips, the actual rotational speed Np of the drive shaft 14 increases rapidly, so the upper limit rotational speed Nlimit calculated by the above equations (1) to (3) increases rapidly. Thereafter, immediately before the slip of the drive wheel 18 is eliminated, the actual rotational speed Np of the drive shaft 14 is suddenly reduced, so that the upper limit rotational speed Nlimit is suddenly reduced. Here, when the over-rotation determination is made when the upper limit rotational speed Nlimit is suddenly decreased, the target rotational speed Netgt may suddenly decrease as the upper limit rotational speed Nlimit is suddenly decreased. In this case, the torque of MG1 is controlled in a direction that prevents the rotation of the crankshaft 20 so as to rapidly decrease the engine rotation speed to the target rotation speed Netgt. According to this torque control, the rotational energy of the crankshaft 20 is converted into the generated energy of MG1, so that the generated power of MG1 increases rapidly. Then, when the generated power that has been rapidly increased is supplied to the battery 23 or the converter, the supplied power may exceed the maximum charging power Win, or an excessive voltage may be instantaneously applied to the converter or the like. In this case, there is a demand for increasing the breakdown voltage of the switching elements of the converter and the inverter, which may cause problems such as an increase in cost.

  Therefore, in the present embodiment, in order to avoid the above situation, a process (prediction process) is performed to predict whether or not the generated power of MG1 increases rapidly due to a rapid decrease in the upper limit rotation speed Nlimit before the overspeed determination is performed. Processing for limiting the target rotational speed Netgt to a lower rotational side than the upper limit rotational speed Nlimit corresponding to the actual rotational speed Np of the drive shaft 14 during the period in which the generated power is expected to increase rapidly (rapid increase prediction period) (reduction process) I do. This avoids a sudden increase in the power generated by MG1 due to the occurrence of slip.

  FIG. 3 shows the procedure of the prediction process and the reduction process according to the present embodiment. This process is repeatedly executed by the HV-ECU 30 at a predetermined cycle, for example.

  In this series of processes, first, in step S10, the prediction process is performed. In this embodiment, when it is determined that the logical product of the following condition (A) and condition (B) is true, it is determined that it is a rapid increase prediction period.

  (A) Condition that the change speed of the actual rotation speed Np of the drive shaft 14 (the rotation change speed ΔNp of the drive shaft 14) is lower than the negative specified speed α (<0): As described above, the upper limit rotation The speed Nlimit is proportional to the actual rotation speed Np of the drive shaft 14 when the actual rotation speed Np of the drive shaft 14 is in a low speed rotation range or a medium speed rotation range. For this reason, when the decrease speed of the actual rotation speed Np of the drive shaft 14 increases in the rotation range, the decrease speed of the upper limit rotation speed Nlimit increases. When the target rotation speed Netgt is limited by the upper limit rotation speed Nlimit and the target rotation speed Netgt decreases rapidly, the power generated by the MG1 increases rapidly in order to control the engine rotation speed to the target rotation speed Netgt. For this reason, the condition (A) is a condition for predicting whether or not the power generated by MG1 increases rapidly. Here, the specified speed α decreases the reliability of the PCU and the battery 23, such as excessive power being supplied to the battery 23 due to a sudden increase in the generated power of the MG1, or excessive voltage being applied to the PCU. It may be set to a value that might cause Note that the rotation change speed ΔNp of the drive shaft 14 may be calculated based on the differential operation value of the output value of the rotation speed sensor 34.

(B) Condition that the target rotational speed Netgt exceeds the specified rotational speed β (> 0): When the target rotational speed Netgt increases, the target rotational speed Netgt is then limited by the upper limit rotational speed Nlimit by the over-rotation prevention control. By rapidly decreasing, the power generated by MG1 is likely to increase rapidly. For this reason, the condition (B) is a condition for predicting whether or not the power generated by MG1 increases rapidly. Here, in the present embodiment, the specified rotational speed β is calculated by the following equations (4) to (7).
NpV = V × 60 × D / (2 × π × r) (4)
Nemax1V = ρ / (1 + ρ) × Ngmax + 1 / (1 + ρ) × NpV (5)
Nemax2V = NpV + γ × Npinmax (6)
β = min (Nemax1V, Nemax2V, Nemax3) (7)
V [m / s]: Vehicle running speed D: Gear ratio of differential gear 16 π: Circumference ratio r [m]: Wheel radius

  The above equation (4) calculates the assumed rotational speed NpV of the drive shaft 14 obtained by converting the traveling speed of the vehicle into the rotational speed of the drive shaft 14, and the above equations (5) and (6) The actual rotational speed Np of the drive shaft 14 in 1) and (2) is replaced with the assumed rotational speed NpV of the drive shaft 14. The prescribed rotational speed β calculated by the above equation (7) is the MG1 upper limit rotational speed when the assumed rotational speed NpV of the drive shaft 14 is assumed to be the actual rotational speed Np of the drive shaft 14 (MG1 assumed upper limit rotational speed Nemax1V). , Calculated as the minimum value of the pinion upper limit rotational speed (pinion assumed upper limit rotational speed Nemax2V) and the engine upper limit rotational speed Nemax3 when the assumed rotational speed NpV of the drive shaft 14 is reached. Here, as shown in FIG. 4A, the actual rotation speed Np (broken line in the figure) of the drive shaft 14 rapidly increases due to the occurrence of the slip of the drive wheel 18, and then the actual rotation of the drive shaft 14 immediately before the slip is eliminated. Even when the speed Np decreases rapidly, the assumed rotational speed NpV (solid line in the figure) of the drive shaft 14 does not change suddenly. For this reason, as shown in FIG. 4B, although the upper limit rotational speed Nlimit (broken line in the figure) based on the actual rotational speed Np of the drive shaft 14 changes suddenly, the MG1 assumed upper limit rotational speed Nemax1V and the pinion assumed upper limit rotational speed Nemax2V. Does not change suddenly, the prescribed rotational speed β (solid line in the figure) does not change suddenly. For this reason, based on the target rotational speed Netgt exceeding the specified rotational speed β, it is possible to appropriately grasp that the drive wheels 18 are slipping, and thereafter the target rotational speed Netgt is limited by the upper limit rotational speed Nlimit. It becomes possible to grasp in advance whether or not the power generated by MG1 will increase rapidly due to this. In the present embodiment, the traveling speed V of the vehicle used for calculating the assumed rotational speed NpV of the drive shaft 14 is calculated based on the output value of the wheel speed sensor 32. This is in view of the fact that the driven wheel 18 does not slip even if the driving wheel 18 slips.

  When it is predicted in step S10 that the generated power of MG1 does not increase rapidly, the process proceeds to step S12, and the target rotation speed calculation process is performed.

  On the other hand, when it is predicted in step S10 that the power generated by MG1 increases rapidly, the process proceeds to step S14, and control (fuel cut control) for stopping fuel injection of the fuel injection valve 19 is performed. This is a process for reducing the electric power generated by MG1 when the engine speed is decreased by MG1 during the reduction process. That is, when the fuel cut control is performed, the torque generation of the engine 10 can be stopped, and the rotational energy of the crankshaft 20 that should be converted into generated energy by the MG1 can be reduced.

In the subsequent step S16, the above-described reduction process is performed. This process is a process for reducing the target rotation speed Netgt in advance so as not to make an over-rotation determination and suppressing a sudden increase in the generated power of MG1. In the present embodiment, the lowering process is a process of limiting the target rotation speed Netgt to a lower rotation side than the upper limit rotation speed Nlimit in accordance with a decrease in the actual rotation speed Np of the drive shaft 14. Specifically, as shown in FIG. 5, the target rotational speed Netgt in the rapid increase prediction period includes the actual rotational speed Np1 and the target rotational speed Ne1 of the drive shaft 14 at the start timing (time t1) of the rapid increase prediction period, and the rapid increase prediction period. Is expressed based on the actual rotation speed Np2 and the target rotation speed Ne2 of the drive shaft 14 at the end timing (time t2). Specifically, the target rotational speed Netgt in the rapid increase prediction period is expressed by the following equations (8) to (10).
Netgt = Ne1-func {x} × (Ne1-Ne2) (8)
func {x} = x (9)
x = (Np1-Np) / (Np1-Np2) (10)

  Here, in this embodiment, as shown in FIG. 6, the target rotational speed Netgt at the time of the lowering process is set to the actual rotational speed Np2 of the drive shaft 14 in the above equation (10), and the assumed rotational speed of the drive shaft 14 at each time. In addition to NpV, the target rotational speed Ne2 in the above equation (8) is calculated by using the above-mentioned prescribed rotational speed β calculated by the above equations (4) to (7). Thereby, the target rotational speed Netgt is appropriately limited in the period from the timing (time t2) determined to be the rapid increase prediction period to the timing (time t3) determined not to be the rapid increase prediction period in the process of step S10. It becomes possible.

  In addition, when the process of step S12, S16 is completed, this series of processes is once complete | finished.

  FIG. 7 shows an example of prediction processing and reduction processing according to the present embodiment. Specifically, FIG. 7 (1-a) shows the transition of the actual rotational speed Np of the drive shaft 14, FIG. 7 (1-b) shows the transition of the upper limit rotational speed Nlimit and the target rotational speed Netgt, (1-c) shows the transition of the total power W of MG1 and MG2 and the battery 23, and FIG. 7 (1-d) shows the transition of the voltage VH applied to the PCU (for example, converter). . In FIG. 7 (1-c), when the total sum W is 0, the battery 23 is not charged or discharged.

  As shown in the figure, when the slip of the drive wheel 18 occurs at time t1, the actual rotational speed Np of the drive shaft 14 increases rapidly and the upper limit rotational speed Nlimit increases rapidly thereafter. At time t2, the actual rotational speed Np of the drive shaft 14 starts to rapidly decrease, so that the generated power of MG1 is predicted to increase rapidly. For this reason, the said reduction process will be performed in the rapid increase prediction period (time t2-t3). Thus, by avoiding a situation in which over-rotation is determined in the sudden increase prediction period, it is possible to avoid a situation in which the total sum W suddenly increases toward the charging side of the battery 23, and the voltage VH becomes a reference voltage (for example, the above-mentioned It is possible to avoid a situation in which the voltage VH exceeds the target value) and becomes excessive.

  Here, FIG. 7 also shows an example of over-rotation prevention control according to the prior art. Specifically, FIGS. 7 (2-a) to 7 (2-d) correspond to FIGS. 7 (1-a) to 7 (1-d) described above.

  According to the prior art, since the reduction process is not performed during the sudden increase prediction period, a situation in which over-rotation determination is caused by a sudden decrease in the upper limit rotational speed Nlimit occurs, so that the total sum W rapidly increases toward the charging side of the battery 23. A situation occurs in which the voltage VH becomes excessive.

  As described above, in the present embodiment, by performing the lowering process in the sudden increase prediction period, it is possible to suppress the sudden increase in the generated power of MG1 due to the rapid decrease in the upper limit rotation speed Nlimit, and the reliability of the PCU and the battery 23 can be suppressed. It is possible to avoid the occurrence of a situation where the performance decreases.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) The condition that the rotational speed change ΔNp of the drive shaft 14 is less than the negative prescribed speed α, and the target rotational speed Netgt is the prescribed rotational speed β calculated by the above equations (4) to (7). When it is determined that the logical product with the condition of exceeding is true, the generated power of MG1 is predicted to increase rapidly. Thereby, the sudden increase in the generated power due to the occurrence of slip of the drive wheels 18 can be predicted with high accuracy.

  (2) The over-rotation prevention control is performed, and the lowering process is performed during the rapid increase prediction period. Thereby, the increase speed of the generated power supplied to the battery 23 can be reduced by avoiding a sudden increase in the generated power of the MG 1 supplied to the battery 23. As a result, the MG1, the pinion gear P, etc., the PCU and the battery Therefore, it is possible to avoid a decrease in the reliability of both of them.

  (3) Fuel cut control was performed during the rapid increase prediction period. Thereby, the generated electric power of MG1 accompanying lowering of an engine speed by torque control of MG1 can be reduced.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

In the present embodiment, the upper limit rotational speed Nlimit in the overspeed prevention control is added to the MG1 upper limit rotational speed Nemax1, the pinion upper limit rotational speed Nemax2, and the engine upper limit rotational speed Nemax3, and the MG1 assumed upper limit calculated by the above equation (5). By calculating as the minimum value of the rotational speed Nemax1V and the pinion assumed upper limit rotational speed Nemax2V calculated by the above equation (6), the deterioration of the reliability of the PCU and the battery 23 due to the sudden increase in the generated power of the MG1 is avoided. To do. That is, the upper limit rotation speed Nlimit is calculated by the following equation (11).
Nlimit = min (Nemax1, Nemax2, Nemax3, Nemax1V, Nemax2V) (11)

  Here, as shown in FIG. 4, even if the actual rotational speed Np of the drive shaft 14 suddenly decreases immediately before the slip is eliminated, the assumed rotational speed NpV of the drive shaft 14 does not rapidly decrease. Therefore, when slippage of the drive wheel 18 occurs, the upper limit rotational speed Nlimit calculated by the above equation (11) is the MG1 assumed upper limit rotational speed Nemax1V and the pinion assumption calculated based on the assumed rotational speed NpV of the drive shaft 14. It is limited by one of the upper limit rotation speed Nemax2V, and does not rapidly decrease as the actual rotation speed Np of the drive shaft 14 decreases rapidly.

  FIG. 8 shows an example of the over-rotation prevention control process according to the present embodiment. Specifically, FIG. 8A shows the transition of the actual rotational speed Np of the drive shaft 14 and the assumed rotational speed NpV of the drive shaft 14, and FIGS. 8B to 8D are diagrams shown above. 7 (1-b) to FIG. 7 (1-d).

  As shown in the figure, the assumed rotation speed NpV of the drive shaft 14 does not change abruptly during a period (time t1 to t2) from when the slip of the drive wheel 18 occurs until the slip is eliminated, so the upper limit rotation speed Nlimit changes abruptly. do not do. For this reason, even when the target rotation speed Netgt is limited by the upper limit rotation speed Nlimit, the upper limit rotation speed Nlimit does not rapidly decrease due to the occurrence of slip of the drive wheels 18, and the generated power of the MG1 does not increase rapidly.

  Thus, in the present embodiment, by performing the over-rotation prevention control in the above-described manner, it is possible to avoid a sudden decrease in the upper limit rotation speed Nlimit due to the occurrence of slip of the drive wheels 18. Furthermore, since the control logic of the over-rotation prevention control that can avoid the decrease in the reliability of the PCU and the battery 23 can be easily constructed by using the control logic of the conventional over-rotation prevention control, the control logic It is also possible to suitably suppress an increase in man-hours required for construction.

(Third embodiment)
Hereinafter, the third embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In the present embodiment, a process (limit value relaxation process) for setting the upper limit value (limit value ΔNetgt) of the decrease speed of the target rotation speed Netgt higher as the decrease speed of the actual rotation speed Np of the drive shaft 14 is higher. , To avoid a sudden increase in the power generated by MG1. That is, for the purpose of avoiding a decrease in drivability due to a sudden change in engine rotation speed, a decrease in reliability of the battery 23 due to charging / discharging a large amount of power, etc., the decrease speed of the target rotation speed Netgt is usually excessive. A process of limiting the decrease speed of the target rotational speed Netgt with the limit value ΔNetgt is performed so as not to increase. Here, the target rotational speed Netgt is calculated based on the vehicle required torque and the actual rotational speed Np of the drive shaft 14 as described above. For this reason, for example, the required torque of the vehicle decreases to reduce the accelerator operation amount for the driver to perform the brake operation from when the slip of the drive wheel 18 occurs until the slip is eliminated, or immediately before the slip of the drive wheel 18 is resolved. When the engine required power decreases due to a sudden decrease in the actual rotational speed Np of the drive wheel 18, the target rotational speed Netgt decreases as shown by a solid line in FIG. However, since the decrease speed of the target rotational speed Netgt is limited by the limit value ΔNetgt, the target rotational speed Netgt (broken line in the figure) becomes the upper limit rotational speed Nlimit depending on the degree of rapid decrease of the upper limit rotational speed Nlimit (dashed line in the figure). The speed of decrease in the target rotational speed Netgt increases rapidly.

  FIG. 10 shows a procedure of limit value relaxation processing according to the present embodiment. This process is repeatedly executed by the HV-ECU 30 at a predetermined cycle, for example.

  In this series of processes, first, in step S18, it is determined whether or not the rotational change speed ΔNp of the drive shaft 14 is negative. This process is a process for determining whether or not the upper limit rotation speed Nlimit calculated by the overspeed prevention control starts to decrease.

  If it is determined in step S18 that the rotational change speed ΔNp of the drive shaft 14 is positive, the process proceeds to step S20, and processing for setting the limit value ΔNetgt in the normal state is performed.

  On the other hand, if an affirmative determination is made in step S18, the process proceeds to step S22, and the limit value relaxation process is performed. The reason why the limit value ΔNetgt is set higher as the decrease speed of the actual rotational speed Np of the drive shaft 14 is higher is to appropriately avoid the situation where the target rotational speed Netgt is limited by the upper limit rotational speed Nlimit. . That is, the higher the decrease speed of the actual rotation speed Np of the drive shaft 14, the higher the decrease speed of the target rotation speed Netgt calculated by the target rotation speed calculation process. However, since the reduction speed of the target rotation speed Netgt is limited by the limit value ΔNetgt, the final reduction speed of the target rotation speed Netgt does not increase so much, and the target rotation speed Netgt is likely to be limited by the upper limit rotation speed Nlimit. Become. For this reason, the reduction speed of the target rotation speed Netgt is increased by relaxing the restriction of the limit value ΔNetgt in the above-described mode. The limit value ΔNetgt may be calculated using a map in which the reduction speed of the actual rotational speed Np of the drive shaft 14 and the limit value ΔNetgt are associated with each other.

  When the processes of steps S20 and S22 are completed, the process proceeds to step S24, where a process of limiting the decrease speed of the target rotational speed Netgt calculated by the target rotational speed calculation process by the set limit value ΔNetgt is performed.

  In addition, when the process of step S24 is completed, this series of processes is once complete | finished.

  As described above, in the present embodiment, the limit value relaxation process, which is a process of increasing the limit value ΔNetgt as the decrease speed of the actual rotation speed Np of the drive shaft 14 is higher, causes the upper limit rotation speed Nlimit to rapidly decrease. In addition, it is possible to avoid a situation in which an overspeed determination is made by permitting an increase in the decrease speed of the target rotation speed Netgt. Accordingly, priority can be given to avoiding a decrease in the reliability of the PCU or the battery 23 caused by an increase in the power generated by the MG1.

(Other embodiments)
Each of the above embodiments may be modified as follows.

  The over-rotation prevention control method is not limited to the one exemplified in the first embodiment. For example, when calculating the upper limit rotational speed Nlimit, one of the MG1 upper limit rotational speed Nemax1 and the pinion upper limit rotational speed Nemax2 may be removed from the above equation (3), or the engine upper limit rotational speed Nemax3 may be removed.

  The method for predicting the sudden increase in the generated power of MG1 is not limited to the method exemplified in the first embodiment. For example, in the calculation of the prescribed rotational speed β in the above condition (B), the engine upper limit rotational speed Nemax3 may be removed from the above equation (7), or the prescribed rotational speed β may be a fixed value. For example, when it is determined that only the condition (A) is satisfied, the generated power may be predicted to increase rapidly. Even in this case, it is possible to predict the sudden increase in the generated power due to the rapid decrease in the upper limit rotational speed Nlimit.

  The method for limiting the target rotation speed Netgt to the lower rotation side than the upper limit rotation speed Nlimit corresponding to the actual rotation speed Np of the drive shaft 14 is not limited to that exemplified in the first embodiment. For example, in the above formulas (8) and (10), the actual rotational speed Np2 and the target rotational speed Ne2 of the drive shaft 14 may be set to zero. In this case, it is possible to avoid a situation in which the overspeed determination is made until the engine 10 is stopped, and it is possible to suppress a sudden increase in the generated power of the MG1. Further, for example, in the above formula (9), func {x} = x ^ 2 and the like, monotonically increasing function where func {x} is X as an independent variable (preferably func {0} = 0, func {1 } = 1). Further, for example, in the sudden increase prediction period, by making the degree of decrease in the target rotational speed Netgt in the first half of this period greater than the degree of decrease in the second half of the period, at least a part of the generated power of MG1 is consumed by MG2. May be performed.

  In the first embodiment, the reduction speed of the target rotation speed Netgt may be lower than the reduction speed of the upper limit rotation speed Nlimit during the reduction process.

  In the first embodiment, the fuel cut control may not be performed during the execution of the lowering process.

  The power split mechanism 12 is not limited to one in which the second rotating body to which the rotating shaft of MG1 is connected is the sun gear S and the third rotating body to which MG2 (drive shaft 14) is connected is the ring gear R. Absent. For example, the second rotating body to which the rotating shaft of MG1 is connected may be the ring gear R, and the third rotating body to which MG2 (drive shaft 14) is connected may be the sun gear S.

  A method for relaxing the upper limit of the reduction speed of the target rotational speed Netgt is not limited to that exemplified in the third embodiment. For example, when it is determined that the decrease speed of the actual rotation speed Np of the drive shaft 14 is equal to or higher than a predetermined speed, the limit value ΔNetgt may be increased by a predetermined amount.

  The method for calculating the traveling speed V of the vehicle is not limited to the method exemplified in the first and second embodiments. For example, when all the wheels are drive wheels 18, an acceleration sensor that detects acceleration in the traveling direction of the vehicle may be provided, and the traveling speed V of the vehicle may be calculated based on an integrated value of output values of the sensors. Further, for example, the traveling speed V of the vehicle may be calculated based on an output value of a means (for example, a navigation system) that acquires information from the outside of the vehicle.

  -Vehicles to which the present invention is applied are not limited to those exemplified in the above embodiments. For example, the present invention may be applied to a vehicle in which the ring gear R and the drive shaft 14 are connected via a speed reduction mechanism or a transmission.

  DESCRIPTION OF SYMBOLS 10 ... Engine, 11a ... 1st motor generator, 11b ... 2nd motor generator, 12 ... Power split mechanism, 18 ... Drive wheel, 19 ... Fuel injection valve, 20 ... Crankshaft, 23 ... Battery, 30 ... HV- ECU (One Embodiment of the control apparatus of a vehicle-mounted motive power generator).

Claims (6)

A power transmission mechanism that enables power transmission between an output shaft of an internal combustion engine, a rotary shaft of a rotating electrical machine, and a drive shaft capable of transmitting power to a drive wheel, and each of the output shaft, the rotary shaft, and the drive shaft has a machine A power transmission mechanism that aligns the rotational speeds of the first rotating body, the second rotating body, and the third rotating body that are connected to each other on a straight line on the alignment chart, and stores the generated power of the rotating electrical machine The upper limit value of the rotation speed of the output shaft is set to a larger value as the rotation speed of the third rotating body is higher, and the rotation speed of the output shaft is set to the upper limit value. In the control device of the in-vehicle power generation device that operates the rotating electrical machine to limit to the following:
A predicting means for predicting a sudden increase in the generated power based on a decreasing speed of the rotating speed of the third rotating body;
And a limiting means for limiting the rotational speed of the output shaft to a lower rotational side than the upper limit value according to the rotational speed of the third rotating body based on the fact that the generated power is predicted to increase rapidly. A control device for a vehicle-mounted power generation device. Conversion means for converting the traveling speed of the vehicle into the rotational speed of the third rotating body;
A calculation means for calculating the upper limit value when the converted rotation speed is assumed to be the actual rotation speed of the third rotating body;
2. The internal combustion engine according to claim 1, wherein the predicting unit predicts a sudden increase in the generated power based on an actual rotation speed of the output shaft being higher than an upper limit value calculated by the calculating unit. Engine control device.   The control device for an in-vehicle power generation device according to claim 1 or 2, wherein the limiting means limits the rotational speed of the output shaft in accordance with a decrease in the rotational speed of the third rotating body.   The in-vehicle system according to any one of claims 1 to 3, wherein the limiting unit performs a process of stopping the supply of fuel to the internal combustion engine in the process of limiting the rotation speed of the output shaft. Control device for power generator. A power transmission mechanism that enables power transmission between an output shaft of an internal combustion engine, a rotary shaft of a rotating electrical machine, and a drive shaft capable of transmitting power to a drive wheel, and each of the output shaft, the rotary shaft, and the drive shaft has a machine A power transmission mechanism that aligns the rotational speeds of the first rotating body, the second rotating body, and the third rotating body that are connected to each other on a straight line on the alignment chart, and stores the generated power of the rotating electrical machine The upper limit value of the rotation speed of the output shaft is set to a larger value as the rotation speed of the third rotating body is higher, and the rotation speed of the output shaft is set to the upper limit value. In the control device of the in-vehicle power generation device that operates the rotating electrical machine to limit to the following:
Means for converting the traveling speed of the vehicle into the rotational speed of the third rotating body;
The upper limit value is set on the basis of the converted rotation speed of the third rotating body. A power transmission mechanism that enables power transmission between an output shaft of an internal combustion engine, a rotary shaft of a rotating electrical machine, and a drive shaft capable of transmitting power to a drive wheel, and each of the output shaft, the rotary shaft, and the drive shaft has a machine A power transmission mechanism that aligns the rotational speeds of the first rotating body, the second rotating body, and the third rotating body that are connected to each other on a straight line on the alignment chart, and stores the generated power of the rotating electrical machine The upper limit value of the rotation speed of the output shaft is set to a larger value as the rotation speed of the third rotating body is higher, and the rotation speed of the output shaft is set to the upper limit value. In the control device of the in-vehicle power generation device that operates the rotating electrical machine to limit to the following:
A control device for an in-vehicle power generation device, comprising: means for relaxing an upper limit of a reduction speed of the rotation speed of the output shaft when a reduction speed of the rotation speed of the third rotating body is high.

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