JP4466510B2 - Torque control device for vehicle - Google Patents

Description

  The present invention relates to a vehicle torque control device that performs torque control of a vehicle based on a required torque requested by a driver.

  Conventionally, in this type of vehicle control device, so-called smoothing control is performed in which the change in the fuel injection amount of the engine is moderated in order to eliminate the acceleration shock at the time of vehicle acceleration accompanying the accelerator operation of the driver. (For example, refer to Patent Documents 1 and 2). Further, the required torque required by the driver is calculated based on the accelerator operation amount by the driver and the engine rotation speed, and the fuel injection amount and the intake air amount are controlled based on the required torque to be generated on the engine output shaft. A vehicle control device that variably controls the output shaft torque has also been proposed (see, for example, Patent Document 3).

  Even in such a vehicle torque control device of Patent Document 3, it is desirable to perform torque smoothing control as in Patent Documents 1 and 2. That is, when the vehicle is accelerated, the accelerator operation amount changes, for example, in a step shape, and the required torque is calculated following the change in the accelerator operation amount. At this time, for example, a second-order lag filter is used as the annealing calculation means, and the required torque is processed by the second-order lag filter to calculate the smoothed torque. The acceleration shock is mitigated by controlling the fuel injection amount and the intake air amount based on the post-annealing torque.

On the other hand, when the engine is idling or accelerating from the idling state, the required torque is corrected by the ISC correction value so that the engine can be operated favorably, and the corrected requested torque is not subjected to a smoothing calculation process. Afterward torque is calculated. In such a case, the ISC correction value is calculated by learning or the like for each engine, but if the ISC correction value varies due to machine difference or learning error, the required torque after correction varies due to the variation. Therefore, even if the driver performs the acceleration operation in the same manner, the acceleration feeling obtained in response thereto is different. Thereby, the problem that the driving | running | working comfort of a vehicle is impaired arises.
JP-A-7-150998 JP-A-11-182294 JP 2002-317681 A

  The main object of the present invention is to provide a vehicle torque control device capable of realizing a desired required torque while achieving a uniform acceleration feeling in the early stage of acceleration.

  In the torque control device of the present invention, the required torque of the vehicle corresponding to the driver's accelerator operation is calculated, and a predetermined smoothing operation is performed on the required torque or a parameter related thereto to calculate a command value torque. Then, torque control of the vehicle is performed based on the command value torque. Further, in such a torque control device, a torque correction value such as an ISC correction value is set based on the driving state of the vehicle each time, and the required torque is appropriately corrected based on the torque correction value. In such a case, the difference in the feeling of acceleration at the early stage of acceleration of the vehicle occurs due to the variation in the torque correction value due to machine difference variation or the like.

  In this respect, in the invention according to claim 1, two calculation means are provided for calculating the command value torque, and the first calculation means is the torque correction value in the initial acceleration period at the time of vehicle acceleration accompanying the accelerator operation. The second calculation means calculates the command value torque by reflecting the torque correction value after the acceleration initial period and calculating the command value torque. To do. Therefore, it is possible to eliminate the difference in the feeling of acceleration due to the variation in the torque correction value in the early stage of acceleration. As a result, it is possible to achieve a desired required torque while achieving a uniform acceleration feeling in the early stage of acceleration.

Further, in the first aspect of the invention, since the smoothing calculation is performed using a second-order lag filter, the change in the command value torque between the initial acceleration period and the target arrival period for reaching the target required torque. Becomes relatively gentle, and the change in the command value torque becomes relatively steep during the intermediate period. In this case, the torque change during acceleration can be made smooth, and the running comfort of the vehicle can be improved.

Further, in the first aspect of the invention, the command by the first calculation means is based on the rate of change of the command value torque by the first calculation means and the rate of change of the command value torque by the second calculation means. Transition from torque control using value torque to torque control using command value torque by the second calculation means is performed. In this case, by switching the command value torque while monitoring the rate of change of each command value torque, it is possible to reduce the torque shock at the time of the switch.

In the second aspect of the present invention, after the rate of change of the command value torque by the first calculation unit becomes maximum, the second calculation unit performs the torque control using the command value torque by the first calculation unit. Transition to torque control using the command value torque is performed. In this case, the vehicle torque increases with the same trend every time until the rate of change of the command value torque by the first calculation means becomes maximum in the initial acceleration period, and then increases while reflecting the torque correction value for each time. Therefore, a desired required torque can be realized while achieving a uniform acceleration feeling in the early stage of acceleration as described above.

In the third aspect of the invention, after the rate of change of the command value torque by the first calculating means becomes maximum, the command value torque is changed by the maximum rate of change. Then, from the torque control using the command value torque by the first calculation means at the timing when the change rate and the change rate of the command value torque by the second calculation means become the same, the command value by the second calculation means Transition to torque control using torque is performed. In this case, the vehicle torque increases in the same manner every time until the rate of change of the command value torque by the first calculation means becomes the maximum in the acceleration initial period, as in the above-described second aspect, and thereafter the torque correction value every time It rises reflecting. Therefore, a desired required torque can be realized while achieving a uniform acceleration feeling in the early stage of acceleration as described above.

  Further, in particular, in the transition period of the above-described two types of torque control, the change rate when the command value torque change rate by the first calculating means is maximized is used, and the torque change rate is made the same and the command value torque is changed. Since the transition is performed, the torque step can be surely eliminated and the command value torque can be switched smoothly.

Further, as described above, the configuration in which the command value torque is switched after the change rate of the command value torque by the first calculating means is maximized (the configurations of claims 2 and 3 ) is described in claim 4 . Thus, the calculation of the command value torque by the second calculation means may be started at the timing when the rate of change of the command value torque by the first calculation means becomes maximum. In short, when the command value torque is calculated by the first and second calculation means from the beginning of acceleration, a difference in the command value torque occurs due to the difference of the torque correction value. However, as described above, the second calculation means By delaying the calculation start of the command value torque, the step due to the difference of the torque correction value is eliminated.

In the third aspect of the present invention , the change rate when the change rate of the command value torque by the first calculation means becomes the maximum in the transition period of the two kinds of torque control described above is used as the reference for the shift determination. Change as follows. That is, in the invention according to claim 5 , after the rate of change of the command value torque by the first calculating means becomes a predetermined specified value, the command value torque is changed by the rate of change of the specified value. . Then, from the torque control using the command value torque by the first calculation means at the timing when the change rate and the change rate of the command value torque by the second calculation means become the same, the command value by the second calculation means Transition to torque control using torque. In this configuration, the vehicle torque rises in the same trend every time until the rate of change of the command value torque by the first calculation means reaches the specified value in the initial acceleration period, and then rises while reflecting the torque correction value for each time. Therefore, a desired required torque can be realized while achieving a uniform acceleration feeling in the early stage of acceleration as described above.

  In particular, in the transition period of the two types of torque control described above, the command value torque is shifted once the torque change rate is set to a specified value, so that the torque step is surely eliminated and the command value torque is switched smoothly. be able to.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings. The present embodiment embodies the present invention as a common rail fuel injection system for a vehicle diesel engine, and a detailed configuration thereof will be described below.

  FIG. 1 is a configuration diagram showing an outline of a common rail fuel injection system. In FIG. 1, a multi-cylinder diesel engine (hereinafter referred to as an engine) 10 is provided with an electromagnetic injector 11 for each cylinder, and these injectors 11 are connected to a common rail (pressure accumulation pipe) 12 common to each cylinder. A high pressure pump 13 as a fuel supply pump is connected to the common rail 12, and high pressure fuel corresponding to the injection pressure is continuously accumulated in the common rail 12 as the high pressure pump 13 is driven. The high-pressure pump 13 is driven as the engine 10 rotates, and fuel is repeatedly sucked and discharged in synchronization with the engine rotation. The high-pressure pump 13 is provided with an electromagnetically driven suction metering valve (SCV) 13a at its fuel suction portion, and the low-pressure fuel pumped from the fuel tank 15 by the feed pump 14 passes through the suction metering valve 13a. And sucked into the fuel chamber of the pump 13.

  The common rail 12 is provided with a common rail pressure sensor 16, and the fuel pressure (common rail pressure) in the common rail 12 is detected by the common rail pressure sensor 16. Although not shown, the common rail 12 is provided with an electromagnetically driven (or mechanical) pressure reducing valve. When the common rail pressure rises excessively, the pressure reducing valve is opened to perform pressure reduction. It has become.

  The ECU 20 is an electronic control unit including a known microcomputer including a CPU, ROM, RAM, EEPROM, and the like. The ECU 20 includes a rotation signal for detecting the rotation speed of the engine in addition to the detection signal of the common rail pressure sensor 16. Detection signals are sequentially input from various sensors such as a speed sensor, an accelerator opening sensor that detects the amount of accelerator operation by the driver, a water temperature sensor that detects the temperature of engine cooling water, and a fuel temperature sensor that detects the fuel temperature in the common rail. . The ECU 20 calculates the common rail pressure based on the common rail pressure signal output from the common rail pressure sensor 16. In addition, the ECU 20 calculates an engine rotation speed, an accelerator opening, an engine water temperature, a fuel temperature, and the like based on various detection signals output from a rotation speed sensor, an accelerator opening sensor, a water temperature sensor, a fuel temperature sensor, and the like. The ECU 20 calculates the required torque required by the driver based on the engine operation information such as the engine speed and the accelerator opening, calculates the fuel injection amount required to realize the required torque, and accordingly The injection control signal is output to the injector 11. Thereby, the fuel injection from the injector 11 to the engine combustion chamber is optimally controlled in each cylinder.

  Further, the ECU 20 calculates a target value of the common rail pressure (injection pressure) based on the engine speed and the fuel injection amount at that time, and the fuel discharge amount of the high-pressure pump 13 so that the actual common rail pressure becomes the target common rail pressure. Feedback control. Actually, the target discharge amount of the high-pressure pump 13 is determined based on the deviation between the target value and the actual value of the common rail pressure, and the opening degree of the suction metering valve 13a of the high-pressure pump 13 is controlled accordingly. At this time, by controlling the energization amount (energization current) to the electromagnetic solenoid of the intake metering valve 13a, the opening degree of the intake metering valve 13a is increased and decreased, and the fuel discharge amount by the high-pressure pump 13 is adjusted accordingly. .

  Here, when the accelerator operation is performed by the driver and the vehicle is accelerated, if the required torque changes suddenly according to the change in the accelerator opening, an acceleration shock occurs due to the sudden change in the fuel injection amount. Therefore, in order to eliminate the acceleration shock, a smoothing calculation is performed on the required torque. More specifically, in the present embodiment, a second-order lag filter is used as the annealing calculation means, and the required torque after annealing is calculated by the second-order lag filter. Then, the fuel injection amount is calculated based on the required torque after the annealing. Hereinafter, the required torque before annealing is also referred to as “target value torque”, and the required torque after annealing is also referred to as “command value torque”. Incidentally, the arithmetic expression of the second-order lag filter is expressed by the following expression (1).

図２は、二次遅れフィルタによるなまし演算を行った場合の指令値トルクの推移を示すタイムチャートである。図２において、タイミングｔ１ではアクセル開度の増加に伴い、指令値トルク（なまし後トルク）が上昇する。このとき、指令値トルクは所定のなまし率でなまされつつ変化し、その後次第に目標値トルク（ドライバが要求する要求トルク）に収束する。なまし演算手段として二次遅れフィルタを用いたことにより、指令値トルクが上昇し始める加速初期期間と、指令値トルクが目標値トルクに到達する付近の目標到達期間とで指令値トルクの変化が比較的緩やかになり、その中間期間で指令値トルクの変化が比較的急峻となる。この場合、加速時におけるトルク変化を滑らかなものとし、車両の走行快適性を高めることができる。

FIG. 2 is a time chart showing the transition of the command value torque when the smoothing calculation by the second-order lag filter is performed. In FIG. 2, at the timing t1, the command value torque (torque after torque) increases as the accelerator opening increases. At this time, the command value torque changes while being smoothed at a predetermined smoothing rate, and then gradually converges to the target value torque (requested torque requested by the driver). By using the second-order lag filter as the annealing calculation means, the command value torque changes between the initial acceleration period in which the command value torque starts to increase and the target arrival period in the vicinity where the command value torque reaches the target value torque. It becomes relatively gradual, and the change in the command value torque becomes relatively steep during the intermediate period. In this case, the torque change during acceleration can be made smooth, and the running comfort of the vehicle can be improved.

  By the way, when the engine 10 is idling or accelerating from the idling state, the required torque is corrected using a torque correction value for idling operation (hereinafter referred to as ISC correction value). Torque control is performed. In such a case, the engine operation state can be maintained by performing torque control using the ISC correction value during idling or after acceleration, but the same accelerator operation is caused by the correction by the ISC correction value. Even if this is done, a difference occurs in the rate of change of the command value torque, resulting in inconvenience that the driver cannot obtain the desired acceleration feeling. At this time, since the ISC correction value varies due to individual differences between engines, learning errors, and the like, the acceleration feeling also varies depending on the variation.

  Incidentally, the ISC correction value is updated at any time during idle operation by the learning process, and when it is determined that the engine is in the idle state, for example, the difference between the target idle rotation speed and the actual engine rotation speed. Based on the ISC correction value is calculated.

  The problem during torque control reflecting the ISC correction value will be described with reference to FIG. In FIG. 3, the reference characteristic not including the ISC correction value is indicated by a two-dot chain line, and the ISC correction characteristic including the ISC correction value is indicated by a solid line. In FIG. 3, the target value torque is A1 in the reference characteristic and the target value torque is A2 in the ISC correction characteristic, and a difference corresponding to the ISC correction value is generated between them. In this case, when the torque change in the initial acceleration period is compared, a difference as shown in the figure occurs, and a difference in the acceleration feeling experienced by the driver occurs.

  Therefore, in the present embodiment, the command value torque is calculated without reflecting the ISC correction value in the initial stage of acceleration and the torque control is performed using the command value torque. Thereafter, the command is performed by reflecting the ISC correction value in the vicinity of the target. A value torque is calculated, and torque control is performed using the command value torque. As a result, a desired required torque is realized while achieving a uniform acceleration feeling in the early stage of acceleration.

  FIG. 4 is a control block diagram showing a control logic related to the required torque smoothing calculation in the present embodiment. In FIG. 4, the required torque is calculated using the accelerator opening and the like as parameters, and the target torque that does not reflect the ISC correction value from the required torque (hereinafter referred to as the first target value torque TR1) and the target torque that reflects the ISC correction value. (Hereinafter referred to as the second target value torque TR2). At this time, the first target value torque TR1 is the same value as the required torque, and the second target value torque TR2 is an added value of the required torque and the ISC correction value.

  Then, the deviation between the first target value torque TR1 and each command value torque is calculated, and the deviation is input to a first LPF (low-pass filter) 31 as a second-order lag filter. Torque (hereinafter referred to as first smoothed torque y1) and its second-order differential value y1 ″ and first-order differential value y1 ′ are calculated. The first order differential value is described with “” ”, and the first order differential value is expressed with“ ′ ”. At this time, the second-order differential value y1 ″ is calculated by the expression (2), the first-order differential value y1 ′ is calculated by the expression (3), and the first smoothed torque y1 is calculated by the expression (4). In the following equations, yi is the current output value, yi-1 is the previous output value, ui is the current input value, and Ts is the sampling time.

一方で、第２目標値トルクＴＲ２と都度の指令値トルクとの偏差を算出するとともに、該偏差を二次遅れフィルタとしての第２ＬＰＦ（ローパスフィルタ）３２に入力する。第２ＬＰＦ３２では、前記入力した偏差と第１ＬＰＦ３１より出力される１階微分値ｙ１’とに基づいてなまし後トルク（以下、第２なまし後トルクｙ２という）とその２階微分値ｙ２”とを算出する。このとき、第２ＬＰＦ３２には、上記のトルク偏差と１階微分値ｙ１’の他に第１なまし後トルクｙ１の２階微分値ｙ１”が入力され、その２階微分値ｙ１”が０となったことを条件に、第２なまし後トルクｙ２の算出が開始される。なお、２階微分値ｙ２”は上記（２）式により算出され、第２なまし後トルクｙ２は上記（４）式により算出される。

On the other hand, a deviation between the second target value torque TR2 and each command value torque is calculated, and the deviation is input to a second LPF (low-pass filter) 32 as a secondary delay filter. In the second LPF 32, the post-smoothing torque (hereinafter referred to as the second post-smoothing torque y2) and the second-order differential value y2 ″ based on the input deviation and the first-order differential value y1 ′ output from the first LPF 31 At this time, the second LPF 32 receives the second-order differential value y1 ″ of the first smoothed torque y1 in addition to the torque deviation and the first-order differential value y1 ′, and the second-order differential value y1. The calculation of the second post-smoothing torque y2 is started on the condition that “0” is 0. The second-order differential value y2 ”is calculated by the above equation (2), and the second post-smoothing torque y2 Is calculated by the above equation (4).

  Further, the condition determination unit 33 calculates the first post-annealing torque y1 based on the second-order differential value y1 "of the first post-annealing torque y1 and the second-order differential value y2" of the second post-annealing torque y2. A transition determination from the control state in which the command value torque is set to the control state in which the second post-smoothing torque y2 is set as the command value torque is performed.

  Based on the determination result of the condition determination unit 33, the annealing value determination unit 34 includes a first post-annealing torque y1 output from the first LPF 31 and a second post-annealing torque y2 output from the second LPF 32. Either is output as the command value torque. When the command value torque is obtained as described above, the fuel injection amount and the like are calculated based on the command value torque.

  FIG. 5 is a time chart showing the transition of the output (torque after annealing), first-order differential value, and second-order differential value with respect to the step input to the second-order lag filter. In FIG. 5, the change rate of the filter output (torque after annealing) becomes maximum at timing t11, and the first-order differential value becomes maximum and the second-order differential value becomes 0 at the same timing. Then, after the timing t11, the first-order differential value gradually decreases and the second-order differential value becomes a negative value. In the present embodiment, paying attention to changes in the output of the second-order lag filter as described above, the first-order differential value, and the second-order differential value over time, the smoothing calculation is performed in the following order and the command value Determine the torque. This will be described with reference to the time chart of FIG. 6A, the final determined command value torque is indicated by a solid line, the first smoothed torque y1 is indicated by a one-dot chain line, and the second smoothed torque y2 is indicated by a two-dot chain line. In (b) and (c), the second-order differential value y1 ″ of the first smoothed torque y1 is represented by a solid line and the second-order differential value y2 ″ of the second smoothed torque y2; The first-order differential value y2 ′ is indicated by a two-dot chain line.

  (1) In FIG. 6, first, in the initial acceleration period T1 immediately after acceleration, the first target value torque is calculated as a value not including the ISC correction value (for example, the ISC correction value is set to 0), and the first target value is also calculated. For the deviation between the value torque and the previous value torque (previous command value torque), a smoothing calculation by a second-order lag filter is performed to calculate the first smoothed torque y1. Then, the first post-annealing torque y1 is set as the command value torque.

  (2) Next, the timing at which the second-order differential value y1 ″ of the first smoothed torque y1 calculated in the above (1) becomes 0, that is, the rate of change of the post-smooth torque y1 (first-order differential value y1). At this time, the second-order differential value y1 ″ of the first smoothed torque y1 becomes 0 (the first smoothed torque y1 Detected that the rate of change is maximized). After that, in the holding period T2 from timing t21 to t22, the maximum value (x1 in the figure) of the change rate of the first post-smoothing torque y1 is held, and the command value torque is sequentially changed so as to change according to the maximum value of the change rate. Calculated.

  Further, after timing t21, the second target value torque reflecting the ISC correction value is calculated, and a second order lag filter is used for the deviation between the second target value torque and the previous value torque (previous command value torque). The second smoothing torque y2 is calculated by performing the smoothing calculation according to. However, at this time, the second post-smoothing torque y2 is not reflected as the command value torque.

  (3) The rate of change (first-order differential value y2 ′) of the second smoothed torque y2 is equal to the rate of change (first-order differential value y1 ′) of the first post-smooth torque y1 held in (2) above. Then, in the target attainment period T3 after that (after timing t22 in FIG. 6), the second post-smoothing torque y2 is set as the command value torque.

  By performing the steps (1) to (3) as described above, in the acceleration initial period T1, the same acceleration feeling is obtained regardless of the ISC correction value, and in the target arrival period T3, the ISC correction value is obtained. A desired required torque reflecting the above can be realized. Further, by providing the holding period T2 at the transition from the acceleration initial period T1 to the target arrival period T3, the torque when the command value torque is shifted from the first smoothed torque y1 to the second smoothed torque y2 Shock can be suppressed.

  FIG. 7 is a flowchart showing a procedure for calculating the command value torque by the annealing calculation. In FIG. 7, “u1” is a target value torque that does not reflect the ISC correction value, and “u2” is a target value torque that reflects the ISC correction value. “Y1” is a filter output (torque after first smoothing) when the ISC correction value is not reflected in the target value torque, and “y2” is a time when the ISC correction value is reflected in the target value torque. Filter output (torque after second annealing). “Y” is the finally determined command value torque.

  In FIG. 7, in step S101, the second-order differential value y1 "of the first smoothed torque y1 is calculated using the target value torque u1, the command value torque y, and its first-order differential value y 'as calculation parameters. Next, in step S102, it is determined whether or not the second-order differential value y1 "is 0 or less. This is a process for determining whether or not the rate of change (first-order differential value y1 ') of the first smoothed torque y1 is maximized. If y1 ″> 0, the process proceeds to step S103, where the first-order differential value y1 ′ is calculated by integrating the second-order differential value y1 ″ of the first smoothed torque y1. In step S104, the first-order differential value y1 'of the first smoothed torque y1 is set as the first-order differential value y' of the command value torque y. Thereafter, in step S110, the command value torque y is calculated by integrating the first-order differential value y 'of the command value torque y.

  If y1 ″ ≦ 0, the process proceeds to step S105, and the second-order differential value of the second smoothed torque y2 using the target value torque u2, the command value torque y, and its first-order differential value y ′ as calculation parameters. y2 ″ is calculated. Thereafter, in step S106, it is determined whether or not the second order differential value y2 ″ is equal to or less than 0. If y2 ″> 0, the process proceeds to step S107, and the first order differential value y ′ of the command value torque y is determined. The previous value is retained (y ′ = y′i−1).

  If y2 ″ ≦ 0, the process proceeds to step S108, where the first-order differential value y2 ′ is calculated by integrating the second-order differential value y2 ″ of the second smoothed torque y2. In the subsequent step S109, the first-order differential value y2 'of the second post-smoothing torque y2 is set as the first-order differential value y' of the command value torque y. Thereafter, in step S110, the command value torque y is calculated by integrating the first-order differential value y 'of the command value torque y.

  FIG. 8 is a flowchart showing the fuel injection control process, and this process is executed by the ECU 20 at predetermined timings.

  In FIG. 8, first, in step S201, various parameters relating to the main injection amount control such as the accelerator opening, the engine speed, and the common rail pressure are read. In the subsequent step S202, the required torque is calculated based on the accelerator opening, the engine speed, and the like. In this required torque calculation process, a command value torque is calculated by performing a smoothing operation using a second-order lag filter on the required torque calculated based on the accelerator opening and the engine speed. At this time, as described above, during acceleration of the vehicle, the command value torque is calculated by switching between the first post-annealing torque and the second post-annealing torque.

  Thereafter, in step S203, a basic injection amount Q is calculated based on the calculated request torque (command value torque). In the following step S204, the injection amount correction amount ΔQ is calculated based on the engine water temperature, the fuel temperature, the common rail pressure, and the like. Here, it is also possible to calculate the injection amount correction amount ΔQ using a known feedback control method such as PI control or PID control. For example, the injection amount correction amount ΔQ is injected based on the vehicle speed deviation between the actual travel speed (vehicle speed) and the target speed. The amount correction amount ΔQ is feedback-calculated.

  Thereafter, in step S205, the target injection amount QFIN is calculated by adding the injection amount correction amount ΔQ to the basic injection amount Q (QFIN = Q + ΔQ). Finally, in step S206, the energization time of the injector 12 is calculated based on the final injection amount QFIN, the other engine speed, and the common rail pressure, and the solenoid coil of the injector 11 of each cylinder is energized based on the energization time. Along with this, fuel injection by the injector 11 is performed.

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

  The command value torque is calculated from the first post-annealing torque y1 (the smoothing value not reflecting the ISC correction value) at the initial stage of acceleration of the vehicle accompanying the driver's accelerator operation, and after the initial acceleration period, The command value torque is calculated from the second post-annealing torque y2 (an annealing value reflecting the ISC correction value). This eliminates the difference in acceleration feeling due to variations in ISC correction values in the early stage of acceleration. Further, the torque value can be finally converged to reflect the ISC correction value. As a result, it is possible to achieve a desired required torque while achieving a uniform acceleration feeling in the early stage of acceleration.

  After the rate of change of the first post-annealing torque y1 becomes maximum, the command value torque is changed by the maximum rate of change, and then the rate of change and the rate of change of the second post-annealing torque y2 Since the torque control using the first post-annealing torque y1 is shifted to the torque control using the second post-annealing torque y2 at the same timing, the torque step is more appropriately eliminated at the time of the transfer, and the command value torque Can be switched smoothly.

  In addition, since the calculation of the second post-smoothing torque y2 is started at the timing when the rate of change of the first post-smoothing torque y1 is maximized, the second post-smoothing torque y2 with respect to the acceleration start timing. The calculation start of is delayed. Thereby, the torque shock at the time of shifting from the torque control by the first post-annealing torque y1 to the torque control by the second post-annealing torque y2 can be suppressed. That is, as shown in FIG. 9A, when calculation of the post-smoothing torques y1 and y2 is started from the beginning of acceleration, there is a step in each of the post-smoothing torques y1 and y2 due to the difference of the ISC correction value. As a result, torque shock may occur when shifting from the first post-annealing torque y1 to the second post-annealing torque y2. On the other hand, as shown in FIG. 9B, by delaying the calculation start of the second post-smoothing torque y2, the step due to the difference of the ISC correction value is eliminated.

  In addition, this invention is not limited to the content of description of the said embodiment, For example, you may implement as follows.

In the above embodiment, when the torque control by the first post-annealing torque y1 is shifted to the torque control by the second post-annealing torque y2, the rate of change of the first post-annealing torque y1 in the holding period T2 in FIG. Although the configuration is such that the same rate of change is maintained when becomes the maximum, this is changed as follows.
(I) After the rate of change of the first post-annealing torque y1 becomes a predetermined specified value, the change rate that has become the specified value is held and the command value torque is changed by the rate of change. Then, at the timing when the rate of change and the rate of change of the second post-annealing torque y2 are the same, a transition from torque control using the first post-annealing torque y1 to torque control using the second post-annealing torque y2 is performed. To do. At this time, for example, a change rate smaller than the maximum change rate of the first post-smoothing torque y1 is determined as the specified value. Also in this configuration, a desired required torque can be realized while achieving a uniform acceleration feeling in the initial stage of acceleration, as in the above embodiment. Further, in the transition period of the command value torque, the torque step can be eliminated and the command value torque can be switched smoothly.
(Ii) Immediately after the rate of change of the first post-annealing torque y1 reaches the maximum (or a predetermined specified value), the torque control using the first post-annealing torque y1 to the torque control using the second post-annealing torque y2 Implement the transition to That is, the holding period T2 is not provided. In this configuration, although there is a possibility that a slight level difference is caused in the torque change, a desired required torque can be realized while achieving a uniform acceleration feeling in the initial stage of acceleration as described above.

  In the above-described embodiment, the acceleration initial period is the time until the rate of change (first-order differential value y1 ′) of the first post-annealing torque y1 during the vehicle acceleration, and the first post-annealing torque in that period. Although the configuration is such that the torque control by y1 is performed, this is changed, and the configuration in which the predetermined time elapses from the start of acceleration is set as the initial acceleration period, and the torque control by the first post-smoothing torque y1 is performed in this period. It is also good.

  In the above-described embodiment, the ISC correction value is exemplified as the torque correction value, but it is also possible to use this as another correction value. For example, an air conditioner correction value for correcting the required torque when the air conditioner is operating is applied as the torque correction value. That is, the required torque is corrected using the air conditioner correction value. In this case, the same processing as described above is performed for the smoothing calculation of the required torque during vehicle acceleration.

  In the above embodiment, the smoothing calculation is performed on the deviation between the target value torque (requested torque) and the command value torque, but this is changed. For example, a smoothing calculation may be performed on the target torque calculated according to the accelerator opening or the like.

  In the above embodiment, the present invention is applied to a vehicle equipped with a diesel engine. However, the present invention can also be applied to a vehicle equipped with a gasoline engine. In this case, torque control is performed by controlling the fuel injection amount and the intake air amount based on the required torque (command value torque) each time.

It is a block diagram which shows the outline of the engine control system in embodiment of invention. It is a time chart which shows transition of command value torque at the time of performing smoothing calculation by a secondary delay filter. It is a time chart for demonstrating the problem at the time of the torque control which reflected the ISC correction value. It is a control block diagram which shows the control logic regarding the smoothing calculation of a request torque. It is a time chart which shows transition of the output with respect to the step input to a secondary delay filter, a 1st-order differential value, and a 2nd-order differential value. It is a time chart which shows the outline | summary of calculation of command value torque concretely. It is a flowchart which shows the calculation process of command value torque. It is a flowchart which shows a fuel-injection control process. It is a time chart for demonstrating the effect of having delayed the calculation start of the 2nd post-annealing torque.

Explanation of symbols

  10 ... engine, 20 ... ECU.

Claims (5)

Calculates the required torque of the vehicle corresponding to the driver's accelerator operation, calculates a command value torque by performing a predetermined smoothing operation on the required torque or a parameter related thereto, and based on the command value torque In a vehicle torque control apparatus that performs vehicle torque control,
In the initial acceleration period at the time of vehicle acceleration accompanying the accelerator operation, the smoothing calculation is performed without reflecting the torque correction value set based on the driving state of each vehicle, and a command value torque is calculated. A calculation means;
A second calculating unit that, after the initial acceleration period, reflects the torque correction value and performs the smoothing calculation to calculate a command value torque;
Equipped with a,
The first calculation means and the second calculation means perform the smoothing operation using a second-order lag filter;
Means for calculating the rate of change of the command value torque by the first calculating unit, and means for calculating the rate of change of the command value torque by the second calculating unit. Based on the torque control using the command value torque by the first calculation unit, the torque control using the command value torque by the second calculation unit is performed. apparatus. After the rate of change of the command value torque by the first calculation means becomes maximum, the command value torque by the second calculation means is used from the torque control using the command value torque by the first calculation means. 2. The vehicle torque control device according to claim 1, wherein a shift to torque control is performed . After the change rate of the command value torque by the first calculation means becomes maximum, the command value torque is changed according to the maximum change rate, and the change rate and the command value torque by the second calculation means are changed. Transition from torque control using the command value torque by the first calculation means to torque control using the command value torque by the second calculation means at a timing at which the change rate of the second calculation means becomes the same. The torque control apparatus for a vehicle according to claim 1 . The vehicle according to claim 2 or 3, wherein calculation of the command value torque by the second calculation means is started at a timing when the rate of change of the command value torque by the first calculation means becomes maximum. Torque control device. After the change rate of the command value torque by the first calculation means becomes a predetermined specified value, the command value torque is changed according to the change rate that has become the specified value, and the change rate and the second calculation are calculated. From the torque control using the command value torque by the first calculation means to the torque control using the command value torque by the second calculation means at a timing when the change rate of the command value torque by the means becomes the same. The vehicle torque control device according to claim 1, wherein the shift is performed .

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