JP2015001205A - Torque control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torque control device for a vehicle capable of suppressing occurrence of a trouble due to existence of output torque of an internal combustion engine in a prescribed torque region, and capable of avoiding torque shock.SOLUTION: In a torque control device for a vehicle V of this invention, F/B control torque TRQFB as target output torque of an internal combustion engine is calculated in accordance with an operation state of the internal combustion engine, limit torque TRQLMT is calculated so as to vary at higher speed when the F/B control torque TRQFB is in a prescribed noise generation torque region, and the limit torque TRQLMT is set as target torque TRQCMD instead of the F/B control torque TRQFB when the F/B control torque TRQFB is in the noise generation torque region, and thus, the internal combustion engine is controlled based on the target torque TRQCMD.

Description

  The present invention relates to a vehicle torque control device that controls output torque of an internal combustion engine in a vehicle in which power of the internal combustion engine is shifted by a transmission and transmitted to drive wheels.

  As a conventional vehicle torque control device, for example, one described in Patent Document 1 below is known. This vehicle includes an engine, a continuously variable transmission (CVT), and wheels connected to these via a drive system. In this torque control device, when the power transmission state between the engine and the CVT side and the wheel side is switched between a driving state where the engine side drives the wheel and a driven state driven by the wheel, the drive system The target torque of the engine is set so as to suppress the longitudinal vibrations of the vehicle caused by backlash in the gears and the like.

  Specifically, the basic target torque is calculated based on the accelerator opening and the engine speed, and a backlash suppression torque smaller than the basic target torque is selected according to the engine speed, the engine water temperature, and the operating state of the auxiliary machine. The suppression control period is calculated according to the backlash suppression torque and the engine speed. The presence or absence of switching of the power transmission state is detected by ON / OFF of an idle switch or the like, and when the switching of the power transmission state is not detected, the target torque is set to the basic target torque.

  On the other hand, when switching of the power transmission state, for example, switching from the driven state on the engine side to the driving state is detected, the target torque is set to a smaller backlash suppression torque, and then the suppression control period has elapsed Then, the target torque is switched to the basic target torque. In this way, the vibration of the vehicle is suppressed by using the backlash suppression torque immediately after the switching of the power transmission state and eliminating the backlash of the drive system.

JP 2000-229526 A

  However, in this conventional torque control device, the target torque of the engine is set stepwise from a smaller backlash suppression torque to a larger basic target torque when the power transmission state is switched. May cause a torque shock and impair drivability.

  In addition, while the basic target torque is calculated based on the accelerator opening and the engine speed, the backlash suppression torque is the basic target torque depending on the engine speed, the engine water temperature, and the operating state of the auxiliary machine. Calculated directly and unrelated. For this reason, the backlash suppression torque may greatly deviate from the basic target torque. In this case, torque control that does not match the operating state of the engine is performed during the suppression control period.

  The present invention has been made to solve such a problem, and it is possible to suppress occurrence of a malfunction due to the output torque of the internal combustion engine being within a predetermined torque region and to avoid a torque shock. An object of the present invention is to provide a vehicle torque control device.

  In order to achieve this object, the invention according to claim 1 of the present application shifts the power of the internal combustion engine 3 with the transmission 4 to drive wheels (front wheels WF and WF in the embodiment (hereinafter the same in this section)). Is a vehicle torque control device for controlling the output torque of the internal combustion engine 3 in the vehicle V to be transmitted to the vehicle V, and is an operation state detection means (crank angle sensor 21) for detecting the operation state (engine speed NE) of the internal combustion engine 3. And first target torque calculating means (ECU 2, FIG. 4) for calculating a first target torque (F / B control torque TRQFB) that is a target of output torque according to the detected operating state of the internal combustion engine 3. The second target torque (limit torque TRQLMT) is set so as to change at a speed larger than the first target torque when the calculated first target torque is within a predetermined torque region where trouble may occur. When the second target torque calculating means (ECU 2, steps 54 and 55 in FIGS. 8 and 10 and step 89 in FIG. 11) to be output and the first target torque is within a predetermined torque region, the first target torque is replaced. Then, target torque setting means (ECU2, step 8 in FIG. 3) for setting the second target torque as the final target torque TRQCMD, and control means (ECU2) for controlling the internal combustion engine 3 based on the set target torque TRQCMD And step 9) of FIG.

  In this vehicle torque control device, a first target torque that is a target of the output torque of the internal combustion engine is calculated in accordance with the detected operating state of the internal combustion engine. Further, when the calculated first target torque is within a predetermined torque region where a malfunction may occur, the second target torque is calculated so as to change at a speed larger than the first target torque. When the first target torque is within the predetermined torque region, the second target torque is set as the final target torque instead of the first target torque, and the internal combustion engine is set based on the set target torque. Control.

  As described above, when the first target torque is within a predetermined torque region where a malfunction may occur, the second target torque having a larger change speed is set as the target torque instead of the first target torque. With this setting, the target torque passes through the predetermined torque region more quickly, so that the occurrence of problems due to the output torque of the internal combustion engine existing in the predetermined torque region can be effectively suppressed. Further, since the second target torque changes gradually, unlike the conventional torque control device, the target torque does not change abruptly, torque shock can be avoided, and output torque commensurate with the operating state of the internal combustion engine can be obtained. Can be obtained.

  According to a second aspect of the present invention, in the vehicle torque control apparatus according to the first aspect, when the second target torque calculating means passes the predetermined torque region from the lower side to the upper side while the first target torque increases, The second target torque is increased from the lower limit value TLMTL to the upper limit value TLMTH in the predetermined torque region at an increase rate (torque increase / decrease amount ΔTRQ) larger than the first target torque, and then the first target torque is increased to the upper limit value TLMTH. The second target torque is maintained at the upper limit value TLMTH until it reaches (steps 52 and 54 to 57 in FIG. 10).

  In this configuration, when the first target torque passes through the predetermined torque region while increasing, the second target torque increases at an increase rate larger than the first target torque, so that the time during which the target torque exists in the predetermined torque region Can be reliably shortened. Further, since the second target torque increases with the lower limit value of the predetermined torque region as an initial value, the continuity of the target torque is ensured when switching to the second target torque when the first target torque enters the predetermined torque region. Thus, torque shock at the time of switching can be surely avoided.

  In addition, the second target torque increases at a larger increase rate than the first target torque, and is held at this upper limit value until the first target torque reaches the upper limit value of the predetermined torque region. As a result, by setting the target torque to a larger value than in the case of the first target torque, it is possible to prevent engine stall due to insufficient target torque. For the same reason, the continuity of the target torque can be ensured when switching from the second target torque to the first target torque when the first target torque goes out of the predetermined torque region, and torque shock at the time of switching can be ensured. Can be avoided.

  According to a third aspect of the present invention, in the vehicle torque control apparatus according to the first or second aspect, the second target torque calculating means passes the predetermined torque region from the upper side to the lower side while the first target torque is decreasing. Sometimes, the second target torque is held at the upper limit value TLMTH of the predetermined torque region until the first target torque reaches the lower limit value TLMTL of the predetermined torque region, and then the second target torque matches the first target torque. Until the first target torque, it is characterized by a decrease (torque increase / decrease amount ΔTRQ) (steps 84, 86, 89 to 91 in FIG. 11).

  According to this configuration, when the first target torque passes through the predetermined torque region while decreasing, the second target torque is maintained at the upper limit value of the predetermined torque region until the first target torque reaches the lower limit value of the predetermined torque region. Is done. Thereby, the continuity of the target torque at the time of switching to the second target torque when the first target torque enters the predetermined torque region can be ensured, and the torque shock at the time of switching can be surely avoided, and the first target torque can be avoided. By setting the target torque to a larger value than in the case of torque, engine stall due to lack of target torque can be prevented.

  Thereafter, the second target torque decreases at a decreasing rate larger than the first target torque until it matches the first target torque, so that the time during which the target torque exists in the predetermined torque region can be reliably shortened, The continuity of the target torque at the time of switching from the two target torques to the first target torque can be ensured, and the torque shock at the time of switching can be surely avoided.

  According to a fourth aspect of the present invention, in the vehicle torque control device according to the second or third aspect, the speed of increase or decrease of the second target torque as the speed ratio of the transmission 4 is larger (the gear stage SGR is lower). A torque change speed setting means (ECU 2, step 44 in FIG. 8, FIG. 9) for setting (torque increase / decrease amount ΔTRQ) to a smaller value is further provided.

  The larger the gear ratio of the transmission, that is, the lower the speed, the greater the torque shock that occurs with changes in the output torque of the internal combustion engine. According to this configuration, as the speed ratio of the transmission is larger, the speed of increase or decrease of the second target torque is set to a smaller value, so that torque shock especially when the speed ratio is on the low speed side can be suppressed, It is possible to realize in a well-balanced manner the suppression of problems caused by the output torque of the internal combustion engine being within a predetermined torque region and the suppression of torque shocks according to the gear ratio.

  The invention according to claim 5 is the vehicle torque control device according to any one of claims 1 to 4, further comprising a rotation speed detection means (crank angle sensor 21) for detecting the rotation speed NE of the internal combustion engine 3. The first target torque calculating means calculates a first target torque (F / B control torque TRQFB) by proportional-integral control so that the detected rotational speed NE of the internal combustion engine 3 converges to a predetermined target rotational speed NECMD ( 4), changing means (ECU2, step 21 in FIG. 4, FIG. 4) for changing the upper limit value TFBILMT that defines the upper limit of the integral term TFBI of the proportional integral control in accordance with the gear ratio (gear stage SGR) of the transmission 4. 5) is further provided.

  According to this configuration, the first target torque is calculated by proportional-integral control so that the detected rotational speed of the internal combustion engine converges to the predetermined target rotational speed. The integral term of this proportional integral control is limited by the upper limit value. Due to this limitation, it is possible to appropriately avoid the phenomenon that the first target torque and the rotational speed of the internal combustion engine, which once increase due to accumulation of integral terms in proportional integral control, are less likely to decrease. Further, since the upper limit value is changed according to the transmission gear ratio, for example, when the gear ratio is large (the gear stage is low), the upper limit value is set to a relatively large value by setting the upper limit value to a relatively large value. The restriction by the value can be relaxed, and the starting performance of the vehicle on the low speed side can be ensured appropriately.

  According to a sixth aspect of the present invention, in the vehicle torque control apparatus according to any one of the first to fifth aspects, the predetermined torque region is an abnormal noise generation torque region in which abnormal noise is likely to occur, and the abnormal noise generation torque region. The upper limit value TLMTH and the lower limit value TLMTL are the amplitude of the transmission input torque TRQIN that is input to the transmission 4 in a vibrating state, the driving state in which the internal combustion engine 3 drives the driving wheels, and the internal combustion engine 3 is driven by the driving wheels. It is characterized in that it is set based on a relationship with a predetermined torque value (value 0) corresponding to the boundary with the driven state (FIGS. 6 and 7).

  According to this configuration, the predetermined torque region is an abnormal noise generation torque region in which abnormal noise is likely to occur, and the abnormal noise generation torque region is set as follows. That is, in a vehicle having an internal combustion engine, a transmission, and drive wheels as the object of the present invention, the main source of abnormal noise is that the power transmission state between the internal combustion engine and the drive wheels is driven by the internal combustion engine. Between a driving state for driving the wheels (hereinafter referred to as “driving state of the internal combustion engine”) and a driven state in which the internal combustion engine is driven by the driving wheels during deceleration (hereinafter referred to as “driven state of the internal combustion engine”) Is a rattling noise caused by backlash generated in a gear or the like disposed in the transmission, and this rattling noise is transmitted to the passenger compartment and is perceived as an abnormal noise. Therefore, when the transmission input torque input to the transmission crosses (crosses) a predetermined torque value corresponding to the boundary between the driving state and the driven state of the internal combustion engine, for example, a value 0, noise is likely to occur. Become.

  Further, the transmission input torque vibrates with a certain amplitude, and even when the peak portion (peak portion or trough portion) of the amplitude slightly crosses the predetermined torque value, there is a possibility that abnormal noise may be generated. From such a viewpoint, according to the present invention, the upper limit value and the lower limit value of the abnormal noise generation torque region for the output torque of the internal combustion engine are set based on the relationship between the amplitude of the transmission input torque and the predetermined torque value.

  By setting the upper limit value and the lower limit value as described above, the abnormal noise generation torque region of the output torque of the internal combustion engine can be appropriately set based on the transmission input torque, and the output torque is within the abnormal noise generation torque region. The generation of abnormal noise can be appropriately suppressed by shortening the time existing in.

  The invention according to claim 7 is the vehicle torque control apparatus according to claim 6, wherein the transmission 4 is a stepped transmission that sets a gear ratio by a plurality of gear stages SGR, and the vehicle V is stopped. Further provided is prohibiting means (ECU 2, steps 5 and 6 in FIG. 3) for prohibiting calculation of the second target torque by the second target torque calculating means when in the idle operation state or when the transmission 4 is in the neutral state. It is characterized by.

  When the vehicle is in an idle driving state or when the transmission is in a neutral state, abnormal noise is generated because there is no switching between the driving state and driven state of the internal combustion engine, which is the cause of abnormal noise. There is no fear. Based on this viewpoint, according to the present invention, in the above two states, the calculation of the unnecessary second target torque is prohibited and the first target torque is used as the target torque. The original torque control can be performed.

  The invention according to claim 8 is the vehicle torque control apparatus according to claim 6 or 7, wherein the transmission 4 is a stepped transmission that sets a gear ratio by a plurality of gear stages SGR. When the gear stage SGR is set to a predetermined gear stage that is unlikely to generate abnormal noise, the second target torque calculating means prohibits the calculation of the second target torque by the second target torque calculating unit (ECU 2, steps 5 and 6 in FIG. 3). ) Is further provided.

  When the transmission is a stepped transmission, it has been found that the occurrence of abnormal noise differs depending on the set gear stage, and it is difficult for abnormal noise to occur when a predetermined gear stage, for example, a low-speed gear stage is used. Based on this viewpoint, according to the present invention, when the gear stage of the transmission is set to a predetermined gear stage that is unlikely to generate abnormal noise, the calculation of the second target torque, which is less necessary, is prohibited, Since one target torque is used as the target torque, the original torque control according to the operation state of the internal combustion engine can be performed.

It is a figure showing roughly some vehicles to which the present invention is applied. It is a block diagram which shows a torque control apparatus. It is a flowchart which shows the main flow of a torque control process. It is a flowchart which shows the subroutine of the calculation process of F / B control torque. It is a table for calculating the limit value of an integral term. It is a flowchart which shows the subroutine of the setting process of an abnormal sound generation torque area | region. It is a figure which shows the setting method of the upper limit of a transmission input torque, and a lower limit. It is a flowchart which shows the subroutine of the calculation process of a limitation torque. It is a table for calculating the torque increase / decrease amount. It is a flowchart which shows the subroutine of the control process at the time of torque increase. It is a flowchart which shows the subroutine of the control process at the time of torque reduction. It is a timing chart which shows the operation example obtained by a torque control process. It is a timing chart which shows the other example of operation obtained by torque control processing. It is a timing chart which shows another example of operation obtained by torque control processing.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. A vehicle V shown in FIG. 1 is a four-wheeled vehicle having left and right front wheels WF and WF and left and right rear wheels (not shown), and an internal combustion engine (hereinafter referred to as “engine”) 3 and a speed change at the front thereof. Machine 4 is installed.

  The engine 3 is, for example, a diesel engine, and each cylinder (not shown) is provided with a fuel injection valve 10 (see FIG. 2). Torque is output from the engine 3 when the air-fuel mixture of the fuel injected from the fuel injection valve 10 and the sucked air burns in the cylinder. The output torque of the engine 3 is controlled by controlling the fuel injection amount and fuel injection timing by the fuel injection valve 10 with a control signal from the ECU 2.

  The crankshaft 3 a of the engine 3 is connected to the input shaft 4 a of the transmission 4 via the flywheel 5 and the clutch 6. The transmission 4 is of a manual type, and according to an operation position of a shift lever (not shown), for example, a built-in gear mechanism (none of which is shown) allows, for example, six forward gears and one reverse gear. Selectively set the neutral state. The output gear 4 b of the transmission 4 is meshed with the reduction gear 7 a of the differential gear 7.

  The power of the engine 3 is input to the transmission 4 via the input shaft 4a with the clutch 6 connected, and after being shifted by the transmission 4, the differential gear 7 is transmitted from the output gear 4b via the reduction gear 7a. To the left and right front wheels WF and WF via the left and right drive shafts 8 and 8. An auxiliary machine 9 including an air conditioner compressor (not shown) is connected to the engine 3, and the auxiliary machine 9 is driven by the power of the engine 3.

  A crank angle sensor 21 is provided on the crankshaft 3a. The crank angle sensor 21 outputs a CRK signal that is a pulse signal at every predetermined crank angle (for example, 30 °) with the rotation of the crankshaft 3a. The ECU 2 calculates the engine speed (hereinafter referred to as “engine speed”) NE of the engine 3 based on the CRK signal.

  As shown in FIG. 2, the ECU 2 receives from the accelerator opening sensor 22 a detection signal representing the depression amount (hereinafter referred to as “accelerator opening”) AP of an accelerator pedal (not shown) of the vehicle V. The

  Further, the ECU 2 detects from the gear speed sensor 23 a detection signal indicating the gear speed SGR including the neutral state, which is set in the transmission 4, from the vehicle speed sensor 24, indicating the speed (vehicle speed) VP of the vehicle V. A detection signal indicating the temperature of intake air (intake air temperature) TA taken into the engine 3 is input from the intake air temperature sensor 25, and a detection signal indicating the connection / disconnection state of the clutch 6 is input from the clutch sensor 26, respectively. Is done.

  The ECU 2 is composed of a microcomputer including a CPU, a RAM, a ROM, an I / O interface (all not shown), and the like. The ECU 2 discriminates the operating state of the vehicle V and the engine 3 according to the detection signals of the various sensors 21 to 26 described above and the like, and torque control for controlling the output torque of the engine 3 according to the discriminated operating state. Various control processes including are executed.

  In the present embodiment, the ECU 2 corresponds to first target torque calculation means, second target torque calculation means, target torque setting means, control means, torque change speed setting means, change means, and prohibition means.

  FIG. 3 shows a main flow of torque control processing executed by the ECU 2 while the vehicle V is traveling. This process is repeatedly executed every predetermined time. In this process, first, in step 1 (illustrated as “S1”, the same applies hereinafter), it is determined whether or not the target rotational speed control flag F_FBNE is “1”.

  This target rotational speed control flag F_FBNE is set to “1” when the execution condition for the target rotational speed control is satisfied. Further, the target rotational speed control is performed when the vehicle V is in a predetermined traveling state, for example, when the vehicle V is coasting in a state where the distance from the vehicle ahead is small, the clutch 6 is connected, and the accelerator pedal is not depressed. The engine output torque of the engine 3 is controlled so that the engine rotational speed NE becomes a predetermined target rotational speed NECMD when the vehicle is traveling at.

  If the answer to step 1 is NO and the execution condition for target speed control is not satisfied, the process proceeds to step 2 to search a predetermined map (not shown) according to the accelerator opening AP and the engine speed NE. As a result, the target torque TRQCMD that is the target of the output torque of the engine 3 is calculated.

  When the answer to the above step 1 is YES and the execution condition of the target rotational speed control is satisfied, the F / B (feedback) control torque TRQFB is calculated (step 3). The F / B control torque TRQFB is calculated by PID feedback control so that the engine speed NE converges to the target speed NECMD in the target speed control. Details of the calculation process will be described later.

  Next, an abnormal noise generation torque region is set (step 4). This abnormal noise generation torque region corresponds to a torque region in which abnormal noise is likely to occur in the output torque region of the engine 3. Details of the setting process will be described later.

  Next, it is determined whether or not the torque limit control flag F_LMMTRQ is “1” (step 5). This torque limit control flag F_LMMTRQ is set to “1” when the execution condition for torque limit control is satisfied. Further, in the torque limit control, when the F / B control torque TRQFB is in the abnormal noise generation torque region, the target torque TRQCMD is replaced with the F / B control torque TRQFB in order to suppress the generation of abnormal noise. By using the limit torque TRQLMT calculated as described later, the output torque of the engine 3 is limited so as to pass through the abnormal noise generation torque region more quickly.

For this reason, the following condition (a) is set as an execution condition for torque limit control.
(A) The F / B control torque TRQ is in the abnormal noise generation torque region. In addition to this condition (a), the execution conditions for torque limit control include the following conditions (b) to (g). As appropriate, the selected conditions are included.
(B) The vehicle speed VP is not 0 and the clutch 6 is connected. (C) The transmission 4 is not in the neutral state. (D) The change amount of the D term of the F / B control torque TRQFB is less than a predetermined value. (E) Sensor failure has not been detected (f) Cruise control or vehicle behavior stability control has not been performed (g) Gear stage SGR is greater than or equal to a predetermined gear stage

  When all of the above conditions (a) and the selected conditions are satisfied, the torque limit control flag F_LMTRRQ is set to “1”, assuming that the execution condition of the torque limit control is satisfied. Is not established, the torque limit control flag F_LMTRRQ is set to “0”, assuming that the execution condition of the torque limit control is not satisfied.

  From the above condition (b), for example, when the vehicle V is in an idling operation state in which it is stopped, the torque limit control is prohibited. Further, the condition (d) is to prevent interference with PID feedback control for calculating the F / B control torque TRQFB, in particular, deterioration of responsiveness of PID feedback control that should be obtained by the D term. The condition (f) is to prevent interference with cruise control or torque control for vehicle behavior stability control. Furthermore, the condition (g) indicates that when the gear stage SGR is lower than the predetermined gear stage, it is recognized that abnormal noise is less likely to be generated. Therefore, it is necessary to execute torque limit control to suppress abnormal noise. This is because the nature is poor.

  From the above, when the answer to step 5 is NO and the execution condition of the torque limit control is not satisfied, the target torque TRQCMD is set to the F / B control torque TRQFB without executing the torque limit control (step 6). ). On the other hand, when the answer to step 5 is YES and the execution condition of the torque limit control is satisfied, the limit torque TRQLMT is calculated as described later (step 7) and the calculated limit torque TRQLMT is calculated as the torque limit control. The target torque TRQCMD is set (step 8).

  Finally, the engine 3 is controlled based on the target torque TRQCMD and the engine speed NE set in the step 2, 6 or 8 (step 9), and this process is terminated. Specifically, the output torque of the engine 3 is controlled by calculating the fuel injection amount and the fuel injection timing according to the target torque TRQCMD and the engine speed NE and outputting a drive signal based on the fuel injection amount and the fuel injection timing 10 to the fuel injection valve 10. .

  FIG. 4 shows a subroutine for the F / B control torque TRQFB calculation process executed in step 3 of FIG. In this process, first, in step 11, it is determined whether or not the previous value F_FBNEZ of the target rotation speed control flag is “1”. When the answer is YES, that is, immediately after the execution condition of the target rotational speed control is satisfied, the target torque TRQCMD set at that time is set as the initial value of the I term TFBI of the F / B control torque TRQFB. (Step 12).

  After step 12, or when the answer to step 11 is NO, in step 13, it is determined whether or not the torque limit control flag F_LMMTRQ is “1”. If the answer is NO and torque limit control is not being executed, the P-term gain KP, the I-term gain KI, and the D-term gain KI are respectively set to predetermined normal control gains KP1, KI1, and KD1 (step 14). ). On the other hand, when the answer to step 13 is YES and the torque limiting control is being executed, the P term gain KP and the I term gain KI are used to increase the calculation speed of the F / B control torque TRQFB within the abnormal noise generation torque region. And the D-term gain KD are respectively set to predetermined torques KP2, KI2, and KD2 for torque control that are larger than the above-described normal control gains KP1, KI1, and KD1 (step 15).

  In Step 16 following Step 14 or 15, the difference between the target engine speed NECMD and the actual engine speed NE (= NECMD-NE) is calculated as the engine speed deviation ERRNE. Next, the difference (= ERRNE (n) −ERRNE (n−1)) between the current value ERRNE (n) and the previous value ERRNE (n−1) of the rotational speed deviation is calculated as the rotational speed deviation change amount DERRNE. (Step 17).

  Next, the P-term TFBP is calculated by multiplying the rotation speed deviation ERRNE calculated in step 16 by the P-term gain KP (step 18). Also, the current I term TFBI is calculated by multiplying the rotational speed deviation ERRNE by the I term gain KI and adding the previous value TFBI of the I term (step 19). Further, the D term TFBD is calculated by multiplying the rotational speed deviation change amount DERRNE calculated in step 17 by the D term gain KD (step 20).

  In subsequent steps 21 to 23, limit processing on the upper limit side of the I term TFBI is executed. First, the upper limit value TFBILMT of the I term TFBI is calculated by searching the table of FIG. 5 according to the gear stage SGR (step 21). In this table, the upper limit value TFBILMT is set to a very large first predetermined value TLMT1 when the gear stage SGR is the first speed stage or the second speed stage, and when the gear stage SGR is the third speed stage to the sixth speed stage, The second predetermined value TLMT2 is set.

  Next, it is determined whether or not the I term TFBI calculated in step 19 exceeds the upper limit value TFBILMT (step 22). When TFBI> TFBILMT, the I term TFBI is set to the upper limit value TFBILMT, Limit (step 23).

  By the above limit processing, it is possible to avoid the phenomenon that the F / B control torque TRQFB and the engine rotational speed NE once rise and are less likely to decrease due to accumulation of the I term TFBI in PID feedback control. . Further, when the gear stage SGR is the first speed stage or the second speed stage, the upper limit value TFBILMT is set to a very large first predetermined value TLMT1, thereby substantially limiting the I term TFBI by the upper limit value TFBILMT. By being prohibited, it is possible to ensure the start performance of the vehicle V at the low speed stage.

  Finally, the P term TFBP calculated as described above, the sum of the I term TFBI and the D term TFBD is calculated as the F / B control torque TRQFB (step 24), and this process is terminated.

  FIG. 6 shows a subroutine for an abnormal noise generation torque region setting process executed in step 4 of FIG. In this process, first, in step 31, the upper limit value TINLMTH and the lower limit value TINLMTL of the transmission input torque TRQIN stored in the ECU 2 are read. These upper and lower limit values TINLMTH and TINLMTL are set in advance as upper and lower limits of a torque region where abnormal noise can occur with respect to the transmission input torque TRQIN input to the input shaft 4a of the transmission 4. The setting method will be described below.

  FIG. 7 schematically shows the state of the transmission input torque TRQIN. In the figure, the region of the transmission input torque TRQIN larger than the value 0 represents a driving state in which the engine 3 drives the front wheels WF, and the region of the transmission input torque TRQIN smaller than the value 0 represents the engine during deceleration. 3 represents a driven state driven by the front wheel WF. As described above, the switching between the driving state and the driven state of the engine 3 causes the generation of abnormal noise, and accordingly, when the transmission input torque TRQIN crosses the value 0 (strides). In addition, abnormal noise is likely to occur.

  Further, as shown in the figure, the transmission input torque TRQIN vibrates with a certain amplitude, and even when the peak portion (peak portion or trough portion) of the amplitude slightly crosses the value 0, abnormal noise is generated. May occur. From this point of view, as shown in the figure, the upper limit value TINLMTH of the transmission input torque TRQIN is the center of the transmission input torque TRQIN when the trough of the transmission input torque TRQIN is in a limit state that crosses the value 0. Is set to a value. Similarly, the lower limit value TINLMTL is set to the center value of the transmission input torque TRQIN when the peak portion of the transmission input torque TRQIN is in a limit state that crosses the value 0. By setting the upper and lower limit values TINLMTH and TINLMTL as described above, it is possible to appropriately set the abnormal noise generation torque region related to the transmission input torque TRQIN.

  Returning to FIG. 6, in step 32 following step 31, the friction torque TRQFR is calculated. The friction torque TRQFR corresponds to the torque consumed by the friction between the piston and the cylinder among the output torque generated by the combustion of the air-fuel mixture in the engine 3.

  Next, the auxiliary machine torque TRQAC is calculated (step 33). The auxiliary machine torque TRQAC corresponds to the amount of torque consumed to drive the auxiliary machine 9 out of the output torque of the engine 3.

  Next, by adding the friction torque TRQFR and the auxiliary machine torque TRQAC to the upper limit value TINLMTH of the transmission input torque TRQIN, it is converted into the output torque of the engine 3, and as the upper limit value TLMTH of the abnormal noise generation torque region with respect to the output torque Set (step 34). Similarly, by adding the friction torque TRQFR and the auxiliary machine torque TRQAC to the lower limit value TINLMTL of the transmission input torque TRQIN, it is converted into the output torque of the engine 3, and is set as the lower limit value TLMTL of the abnormal noise generation torque region with respect to the output torque. The setting is made (step 35), and this process ends.

  FIG. 8 shows a subroutine of the limit torque TRQLMT calculation process executed in step 7 of FIG. In this process, first, in steps 41 and 42, it is determined whether or not a torque increase control flag F_TRQINC and a torque decrease control flag F_TRQDEC, which will be described later, are “1”, respectively. If both of these answers are NO and immediately after the torque limit control is started, the counter value (hereinafter referred to as “strike counter value”) CCRS is reset to 0 (step 43). This straddle counter value CCRS represents the number of times that the F / B control torque TRQFB has crossed the upper limit or lower limit of the abnormal noise occurrence torque region during the torque limit control.

  Next, a torque increase / decrease amount ΔTRQ is calculated (step 44). This torque increase / decrease amount ΔTRQ is used to increase or decrease the limit torque TRQLMT in the torque limit control, and is calculated by searching the table shown in FIG. 9 according to the gear stage SGR. In this table, the torque increase / decrease amount ΔTRQ is set to a relatively large value such that the increase / decrease speed of the limit torque TRQLMT thereby exceeds the increase / decrease speed of the F / B control torque TRQFB. Further, the torque increase / decrease amount ΔTRQ is set to a smaller value because the torque shock is more likely to appear as the gear stage SGR is lower.

  Next, it is determined whether or not the previous value TRQFBZ of the F / B control torque is smaller than the lower limit value TLMTL of the abnormal noise generation torque region (step 45). When the answer is YES, that is, when the F / B control torque TRQFB increases and enters the abnormal noise generation torque region from the lower side, the torque increase time control flag F_TRQINC is set to “1” (step 46). Then, the torque increase control is started (step 47), and this process is terminated. Thereafter, the answer to step 41 is YES. In this case, the process proceeds to step 47 and the torque increase control is continued.

  On the other hand, when the answer to step 45 is NO, that is, when the F / B control torque TRQFB decreases and enters the abnormal sound generation torque region from the upper side, the torque decrease control flag F_TRQDEC is set to “1” ( At the same time as step 48), torque reduction control is started (step 49), and this process is terminated. Thereafter, the answer to step 42 is YES. In this case, the process proceeds to step 49, and the torque reduction control is continued.

  FIG. 10 shows a subroutine of the above torque increase control process. In this process, first, in step 51, it is determined whether or not the F / B control torque TRQFB is not less than the lower limit value TLMTL and not more than the upper limit value TLMTH, that is, whether or not it is in the abnormal noise generation torque region. If the answer is YES, it is determined whether or not the previous value TRQFBZ of the F / B control torque is smaller than the lower limit value TLMTL (step 52).

  When the answer to step 52 is YES, that is, immediately after the F / B control torque TRQFB enters the abnormal noise generation torque region, the straddle counter value CCRS is incremented (step 53) and the lower limit value TLMTL is set to the limit torque. The initial value of TRQLMT is set (step 54).

  After step 54 or when the answer to step 52 is NO and the F / B control torque TRQFB is not immediately after entering the abnormal noise generation torque region, the routine proceeds to step 55, where the torque increase / decrease amount is increased to the limit torque TRQLMT at that time. The current limit torque TRQLMT is calculated by adding ΔTRQ. As described above, since the torque increase / decrease amount ΔTRQ is set to a relatively large value, the limit torque TRQLMT is increased at a larger increase rate than the F / B control torque TRQFB by the addition of the torque increase / decrease amount ΔTRQ.

  Next, it is determined whether or not the calculated limit torque TRQLMT exceeds the upper limit value TLMTH (step 56). If the answer is YES, the limit torque TRQLMT is made to coincide with the upper limit value TLMTH (step 57). After this step 57 or when the answer to step 56 is NO, the process proceeds to step 58, and the elapsed time after the F / B control torque TRQFB exits (releases) the abnormal noise generation torque region is counted in an up-counting manner. The value TMLMT of the leaving timer to be reset is reset to 0, and then the process proceeds to step 71 described later.

  As described above, when the F / B control torque TRQFB increases and enters the abnormal noise generation torque region from the lower side, the limit torque TRQLMT is obtained by sequentially adding the torque increase / decrease amount ΔTRQ to the lower limit value TLMTL. As a result, it increases at an increase rate larger than the F / B control torque TRQFB, and is held at the upper limit value TLMTH after reaching the upper limit value TLMTH (see FIG. 12).

  On the other hand, when the answer to step 51 is NO and the F / B control torque TRQFB is not within the abnormal noise generation torque region, it is determined whether or not the F / B control torque TRQFB is larger than the upper limit value TLMTH (step 59). ), When the answer is YES and the F / B control torque TRQFB comes out above the abnormal noise generation torque region, it is determined whether or not the previous value TRQFBZ of the F / B control torque is equal to or less than the upper limit value TLMTH ( Step 60).

  When the answer to step 60 is YES, that is, immediately after the F / B control torque TRQFB exits from the abnormal noise generation torque region, the straddle counter value CCRS is incremented (step 61). After this step 61 or when the answer to step 60 is NO, the process proceeds to step 62 to make the limit torque TRQLMT coincide with the F / B control torque TRQFB.

  Next, it is determined whether or not the withdrawal timer value TMLMT reset in step 58 is equal to or longer than a predetermined time TREF (step 63). If the answer is no, the process proceeds to step 71 described later. On the other hand, when the answer to step 63 is YES, that is, when the predetermined time TREF has elapsed after the F / B control torque TRQFB has exited the abnormal noise generation torque region, the torque increase control and the torque limit control are terminated. The torque increase control flag F_TRQINC and the torque limit control flag F_LMTRRQ are each reset to “0” (steps 64 and 65), and this process is terminated.

  As described above, after the F / B control torque TRQFB exits to the upper side of the abnormal noise generation torque region, the limit torque TRQLMT is calculated to coincide with the F / B control torque TRQFB, and then a predetermined time TREF has elapsed. When this is done, the torque increase control and the torque limit control are terminated, and the normal target rotational speed control using the F / B control torque TRQFB is resumed.

  Further, when the answer to step 59 is NO, that is, when the F / B control torque TRQFB that has entered the abnormal noise generation torque region from the lower side escapes (returns) to the lower side of the abnormal noise generation torque region, F It is determined whether or not the previous value TRQFBZ of the / B control torque is equal to or greater than the lower limit value TLMTL (step 66).

  If the answer to this step 66 is YES and the F / B control torque TRQFB has just come out below the abnormal noise generation torque region, the straddle counter value CCRS is incremented (step 67). After step 67 or when the answer to step 66 is NO, the process proceeds to step 68, where the current torque limit torque TRQLMT is calculated by subtracting the torque increase / decrease amount ΔTRQ from the torque limit torque TRQLMT at that time. By subtracting this torque increase / decrease amount ΔTRQ, the limit torque TRQLMT decreases at a decrease rate greater than the F / B control torque TRQFB.

  Next, it is determined whether or not the calculated limit torque TRQLMT has become equal to or less than the F / B control torque TRQFB (step 69). If the answer is YES, the limit torque TRQLMT is matched with the F / B control torque TRQFB ( Step 70). After step 70 or when the answer to step 69 is NO, the process proceeds to step 63 and subsequent steps. That is, when the answer to step 63 is YES and the F / B control torque TRQFB exits from the abnormal noise generation torque region and the predetermined time TREF has elapsed, in steps 64 and 65, the torque increase control flag F_TRQINC and the torque limit The control flag F_LMMTRQ is reset to “0”, and the torque increase control and torque limit control are terminated.

  Further, after step 58, or when the answer to step 63 is NO, it is determined whether or not the straddle counter value CCRS is equal to the predetermined number of times CREF (step 71). Exit. On the other hand, when the answer to step 71 is YES, that is, when the number of times that the F / B control torque TRQFB crosses the upper limit or lower limit of the abnormal noise generation torque region reaches the predetermined number CREF, control during torque increase and torque limit It is assumed that the control is terminated, the steps 64 and 65 are executed, and the present process is terminated.

  FIG. 11 shows a subroutine of torque reduction control processing executed in step 49 of FIG. In this process, first, in step 81, it is determined whether or not the F / B control torque TRQFB is not less than the lower limit value TLMTL and not more than the upper limit value TLMTH (whether it is within the abnormal noise generation torque region) If the answer is yes, it is determined whether or not the previous value TRQFBZ of the F / B control torque is larger than the upper limit value TLMTH (step 82).

  If the answer to step 82 is YES, and the F / B control torque TRQFB has just entered the abnormal sound generation torque region from above, the straddle counter value CCRS is incremented (step 83). After step 83 or when the answer to step 82 is NO, the process proceeds to step 84, where the limit torque TRQLMT is made equal to the upper limit value TLMTH. Next, after the withdrawal timer value TMLMT is reset to 0 (step 85), the process proceeds to step 98 described later.

  As described above, when the F / B control torque TRQFB decreases and enters the abnormal noise generation torque region from the upper side, as long as the F / B control torque TRQFB is in the abnormal noise generation torque region, the limit torque TRQLMT is It is held at the upper limit value TLMTH.

  On the other hand, when the answer to step 81 is NO and the F / B control torque TRQFB is not within the abnormal noise generation torque region, it is determined whether or not the F / B control torque TRQFB is smaller than the lower limit value TLMTL (step 86). ). If the answer to this question is YES and the F / B control torque TRQFB has come out below the abnormal noise generation torque region, it is determined whether or not the previous value TRQFBZ of the F / B control torque is equal to or greater than the lower limit value TLMTL (step). 87).

  When the answer to step 87 is YES, that is, immediately after the F / B control torque TRQFB has left the abnormal noise generation torque region, the straddle counter value CCRS is incremented (step 88). After this step 88 or when the answer to step 87 is NO, the process proceeds to step 89, where the current limit torque TRQLMT is calculated by subtracting the torque increase / decrease amount ΔTRQ from the limit torque TRQLMT at that time.

  As described above, after the F / B control torque TRQFB exits from the abnormal noise generation torque region, the limit torque TRQLMT is calculated by sequentially subtracting the torque increase / decrease amount ΔTRQ from the upper limit value TLMTL. Decrease at a speed greater than the B control torque TRQFB (see FIG. 13).

  Next, it is determined whether or not the calculated limit torque TRQLMT has become equal to or less than the F / B control torque TRQFB (step 90). If the answer is YES, the limit torque TRQLMT is matched with the F / B control torque TRQFB ( Step 91). After step 91 or when the answer to step 90 is NO, the routine proceeds to step 92, where it is determined whether or not the withdrawal timer value TMLMT reset at step 85 is equal to or longer than a predetermined time TREF. If the answer is no, the process proceeds to step 98 described later.

  On the other hand, when the answer to step 92 is YES and the F / B control torque TRQFB exits from the abnormal noise generation torque region and the predetermined time TREF has elapsed, the torque reduction control and the torque limit control are terminated. The decrease time control flag F_TRQDEC and the torque limit control flag F_LMMTRQ are each reset to “0” (steps 93 and 94), and this process ends.

  As described above, after the reduced limit torque TRQLMT becomes equal to or less than the F / B control torque TRQFB, the limit torque TRQLMT is calculated so as to coincide with the F / B control torque TRQFB, and the F / B control torque TRQFB is different. When the predetermined time TREF has elapsed after exiting the sound generation torque region, the torque reduction control and the torque limit control are terminated, and the normal target rotational speed control using the F / B control torque TRQFB is resumed.

  When the answer to step 86 is NO, that is, when the F / B control torque TRQFB that has entered the abnormal noise generation torque region from the upper side has escaped (returned) to the upper side of the abnormal noise generation torque region, the F / B It is determined whether or not the previous value TRQFBZ of the control torque is equal to or lower than the upper limit value TLMTH (step 95).

  When the answer to step 95 is YES and immediately after the F / B control torque TRQFB has escaped to the upper side of the abnormal noise generation torque region, the straddle counter value CCRS is incremented (step 96). After this step 96 or when the answer to step 95 is NO, the routine proceeds to step 97, where the limit torque TRQLMT is made to coincide with the F / B control torque TRQFB.

  After step 97, the process proceeds to step 92 and subsequent steps. That is, if the answer to step 92 is YES and the F / B control torque TRQFB exits from the abnormal noise generation torque region and a predetermined time TREF elapses, in steps 93 and 94, the torque decrease control flag F_TRQDEC and the torque limit The control flag F_LMMTRQ is reset to “0”, and the torque reduction control and the torque limit control are ended.

  Further, after step 85 or when the answer to step 92 is NO, it is determined whether or not the straddle counter value CCRS is equal to the predetermined number CREF (step 98). Exit. On the other hand, when the answer to step 98 is YES and the number of times the F / B control torque TRQFB has crossed the abnormal noise generation torque region reaches the predetermined number CREF, the torque reduction control and the torque limit control are terminated. After executing Steps 93 and 94, the present process is terminated.

  Next, operation examples obtained by the torque control process according to the embodiment will be described collectively with reference to FIGS. FIG. 12 shows an example in which the noise generation torque region defined by the upper limit value TLMTH and the lower limit value TLMTL passes from the lower side to the upper side while the F / B control torque TRQFB increases during the target rotation speed control. is there. In this case, the torque increase control in FIG. 10 is executed as the torque limit control (steps 45 to 47 in FIG. 8), and the limit torque TRQLMT calculated thereby is set as the target torque TRQCMD (FIG. 3). Step 8).

  Specifically, when the F / B control torque TRQFB enters the abnormal noise generation torque region from the lower side (t1), steps 54 and 55 are executed in response to the answer to step 52 in FIG. 10 being YES. Thus, the limit torque TRQLMT is calculated by setting the lower limit value TLMTL as an initial value and adding the torque increase / decrease amount ΔTRQ for each processing cycle. As a result, the limit torque TRQLMT indicated by the solid line increases at a greater increase rate than the F / B control torque TRQFB indicated by the dotted line (t1 to t2).

  When the increased limit torque TRQLMT reaches the upper limit value TLMTH (t2), thereafter, the limit torque TRQLMT is held at the upper limit value TLMTH (steps 56 and 57). Thereafter, when the F / B control torque TRQFB comes out above the abnormal noise occurrence torque region (t3), the limit torque TRQLMT is calculated to coincide with the F / B control torque TRQFB (steps 59 and 62). Then, after the F / B control torque TRQFB exits from the abnormal noise generation torque region, when the predetermined time TREF has elapsed, the torque increase control is terminated (steps 63 to 65), and the F / B control torque TRQFB is normal. Return to the target speed control.

  FIG. 13 shows an example in which the F / B control torque TRQFB passes through the abnormal noise generation torque region from the upper side to the lower side while the target rotational speed control is decreasing. In this case, the torque reduction control in FIG. 11 is executed as the torque limit control (steps 45, 48, and 49 in FIG. 8), and the limit torque TRQLMT calculated thereby is set as the target torque TRQCMD ( Step 8 in FIG.

  Specifically, when the F / B control torque TRQFB enters the abnormal noise generation torque region from above (t11), step 84 is executed in response to the answer to step 82 in FIG. 11 being YES, and the limit torque TRQLMT Is held at the upper limit value TLMTH (t11 to t12). Thereafter, when the F / B control torque TRQFB comes out below the abnormal noise generation torque region (t12), the upper limit value TLMTH is set as an initial value, and the torque increase / decrease amount ΔTRQ is subtracted for each processing cycle, whereby the limit torque TRQLMT is calculated. Calculated (steps 86 and 89). As a result, the limit torque TRQLMT decreases at a decreasing rate larger than the F / B control torque TRQFB (t12 to t13).

  When the reduced limit torque TRQLMT becomes equal to or less than the F / B control torque TRQFB (t13), then the limit torque TRQLMT is calculated so as to coincide with the F / B control torque TRQFB (steps 90 and 91). When the predetermined time TREF has elapsed after the F / B control torque TRQFB has escaped from the abnormal noise generation torque region, the torque reduction control is terminated (steps 92 to 94), and the normal target rotational speed control is restored. To do.

  FIG. 14 shows that during the target rotational speed control, the F / B control torque TRQFB enters the abnormal noise generation torque region from the lower side, and then once returns to the lower side, and then enters the abnormal noise generation torque region again. This is an example of finally exiting upward. In this case, the torque increase control in FIG. 10 is executed as the torque limit control (steps 45 to 47 in FIG. 8).

  Specifically, when the F / B control torque TRQFB enters the abnormal noise generation torque region from the lower side (t21), the limit torque TRQLMT is added to the lower limit value TLMTL by adding the torque increase / decrease amount ΔTRQ, as in FIG. To the upper limit value TLMTH at an increasing rate greater than the F / B control torque TRQFB (t21 to t22), and after reaching the upper limit value TLMTH, it is maintained (t22 to t23).

  Thereafter, when the F / B control torque TRQFB returns to the lower side of the abnormal noise generation torque region (t23), the limit torque TRQLMT is increased by subtracting the torque increase / decrease amount ΔTRQ by executing step 68 of FIG. After the value TLMTH is decreased at a rate of decrease larger than the F / B control torque TRQFB (t23 to t24) and becomes equal to or less than the F / B control torque TRQFB, the F / B control torque is executed by executing Steps 69 and 70. It is calculated so as to coincide with TRQFB (t24 to t25).

  After that, when the F / B control torque TRQFB enters the abnormal noise generation torque region again (t25), the torque limit TRQLMT is increased from the lower limit value TLMTL to the upper limit value TLMTH by adding the torque increase / decrease amount ΔTRQ, similarly to the period between t21 and t23. Then, after increasing at a rate of increase greater than the F / B control torque TRQFB, it is held at the upper limit value TLMTH (t25 to t27).

,
When the F / B control torque TRQFB comes out above the abnormal noise occurrence torque region (t7), the limit torque TRQLMT is calculated so as to coincide with the F / B control torque TRQFB (steps 59 and 62). When the predetermined time TREF has elapsed, the torque increase control is terminated.

  Further, as shown in FIG. 14, during the above control, the stride counter value CCRS is incremented every time the F / B control torque TRQFB crosses the upper limit or lower limit of the abnormal noise generation torque region (steps 53, 61, 66). When the straddle counter value CCRS reaches the predetermined number of times CREF, the torque increase control is terminated at that time (steps 71, 64, 65).

  As described above, according to the present embodiment, in the target rotational speed control that is executed when the vehicle V is in the predetermined traveling state, the PID feedback control is performed so that the engine rotational speed NE converges to the target rotational speed NECMD. F / B control torque TRQFB is calculated. Further, when the calculated F / B control torque TRQFB passes while increasing in the abnormal noise generation torque region, the limit torque TRQLMT is increased at a speed greater than the F / B control torque TRQFB by adding the torque increase / decrease amount ΔTRQ. Calculate to increase. On the other hand, when the F / B control torque TRQFB passes while decreasing the abnormal noise generation torque region, the limit torque TRQLMT is decreased at a larger decrease rate than the F / B control torque TRQFB by subtracting the torque increase / decrease amount ΔTRQ. To calculate.

  Then, the limit torque TRQLMT calculated as described above is set as the target torque TRQCMD in the target rotational speed control, instead of the F / B control torque TRQFB. With the above settings, the target torque TRQCMD passes through the abnormal noise generation torque region more quickly, so that the generation of abnormal noise can be effectively suppressed.

  Further, since the limit torque TRQLMT gradually changes in the same direction as the F / B control torque TRQFB, unlike the conventional torque control device, the target torque TRQCMD does not change abruptly and torque shock can be avoided. An output torque commensurate with the operating state of the engine 3 can be obtained, and target speed control can be performed appropriately.

  Furthermore, since the F / B control torque TRQFB and the limit torque TRQLMT are switched in a state where both values match, the continuity of the target torque TRQCMD at the time of switching can be secured, and the torque shock at the time of switching Can also be avoided reliably. Further, since the limit torque TRQLMT is always set to a value larger than the F / B control torque TRQFB, engine stall due to a shortage of the target torque TRQCMD can be prevented.

  Further, since the torque increase / decrease amount ΔTRQ is set to a smaller value as the gear stage SGR of the transmission 4 is lower, torque shock especially at the low speed side can be suppressed, and the output torque of the engine 3 is in the abnormal noise generation torque region. It is possible to achieve a good balance between the suppression of abnormal noise due to the presence of the torque and the suppression of torque shock according to the gear stage SGR.

  Further, as shown in FIG. 7, the transmission when the trough or peak of the amplitude of the transmission input torque TRQIN slightly crosses the torque value 0 representing the boundary between the driving state and the driven state of the engine 3. The center value of the input torque TRQIN is obtained as the upper limit value TINLMT and the lower limit value TINLMTL, and the output torque of the engine 3 corresponding to the upper limit value TINLMT and the lower limit value TINLMTL is determined as the upper limit value TLMTH and the lower limit value of the abnormal noise generation torque region. Set as TLMTL. Accordingly, the region of the output torque of the engine 3 that is likely to generate noise due to switching between the driving state and the driven state of the engine 3 can be appropriately set as the noise generation torque region, and the output torque can be generated. By shortening the time existing in the torque region, occurrence of abnormal noise can be appropriately suppressed.

  Furthermore, when the vehicle V is in an idle driving state when the vehicle is stopped, when the transmission 4 is in a neutral state, or when the gear stage SGR of the transmission 4 is set to the first speed stage or the second speed stage where abnormal noise is unlikely to occur. Since the limit torque TRQLMT is prohibited from being calculated because the limit by the limit torque TRQLMT is unnecessary or less necessary, the target rotational speed control is performed by the original torque control using the F / B control torque TRQFB as the target torque TRQCMD. Can be done appropriately.

  Further, in the PID feedback control for calculating the F / B control torque TRQFB, the I term TFBI is limited by the upper limit value TFBILMT. Therefore, the F / B control torque TRQFB and the engine speed NE caused by accumulation of the I term TFBI. However, it is possible to appropriately avoid the phenomenon that once it rises, it becomes difficult to drop. Further, when the gear stage SGR of the transmission 4 is the first speed stage or the second speed stage, the upper limit value TFBILMT is set to a very large first predetermined value TLMT1, and restriction by the upper limit value TFBILMT is substantially prohibited. Thus, the starting performance of the vehicle V at the low speed stage can be appropriately ensured.

  In addition, this invention can be implemented in various aspects, without being limited to the described embodiment. For example, in the embodiment, an abnormal noise generation torque region in which abnormal noise is likely to occur is set as the predetermined torque region in which the malfunction may occur. However, the present invention is not limited to this, and torque that may cause a malfunction other than abnormal noise is generated. It may be an area. Even in such a case, an effect that the occurrence of a malfunction can be suppressed can be obtained by allowing the target torque to pass through the torque region more quickly.

  In the embodiment, the F / B control torque TRQFB calculated so that the engine rotational speed NE converges to the target rotational speed NECMD in the target rotational speed control is used as the first target torque. Another control torque calculated according to the operating state of the engine 3 may be used. Further, the calculation of the F / B control torque TRQFB is performed by PID feedback control, but of course, it may be performed by PI feedback control.

  In the embodiment, the common torque increase / decrease amount ΔTRQ is used when increasing or decreasing the limit torque TRQLMT, but different increase / decrease amounts may be used.

  Further, the embodiment is an example in which the engine 3 is a diesel engine and the transmission 4 is a manual transmission. However, the present invention is not limited to this, and may be applied to other types of internal combustion engines, transmissions, and combinations thereof. Is possible. Furthermore, the specific method of the control process shown in the embodiment is merely an example, and it is needless to say that another appropriate method may be adopted. In addition, it is possible to appropriately change the detailed configuration within the scope of the gist of the present invention.

2 ECU (first target torque calculating means, second target torque calculating means, target torque setting means, control means, torque change speed setting means, changing means, prohibiting means)
3 Internal combustion engine 4 Transmission 21 Crank angle sensor (operating state detection means)
V vehicle
WF Front wheel (drive wheel)
NE engine speed (operating state of internal combustion engine, speed of internal combustion engine)
TRQFB F / B control torque (first target torque)
TRQLMT limit torque (second target torque)
TRQCMD target torque TLMTH Upper limit value of abnormal noise generation torque range (upper limit value of predetermined torque range)
TLMTL Lower limit value of abnormal noise generation torque range (lower limit value of predetermined torque range)
ΔTRQ Torque increase / decrease (increase / decrease)
SGR transmission gear stage (transmission gear ratio)
NECMD Target rotational speed TFBI F / B control torque I term (proportional integral control integral term)
TFBILMT Upper limit value TRQIN Transmission input torque

Claims (8)

A vehicle torque control device for controlling the output torque of the internal combustion engine in a vehicle in which the power of the internal combustion engine is shifted by a transmission and transmitted to drive wheels,
An operating state detecting means for detecting an operating state of the internal combustion engine;
First target torque calculating means for calculating a first target torque that is a target of the output torque according to the detected operating state of the internal combustion engine;
Second target torque for calculating the second target torque so as to change at a speed larger than the first target torque when the calculated first target torque is within a predetermined torque region where a malfunction may occur. A calculation means;
Target torque setting means for setting the second target torque as a final target torque instead of the first target torque when the first target torque is within the predetermined torque region;
Control means for controlling the internal combustion engine based on the set target torque;
A vehicle torque control device comprising:   The second target torque calculation means is configured to change the second target torque from a lower limit value to an upper limit value of the predetermined torque region when passing the predetermined torque region from the lower side to the upper side while increasing the first target torque. The second target torque is maintained at the upper limit value until the first target torque reaches the upper limit value after increasing at a rate of increase greater than the first target torque. Item 2. The vehicle torque control device according to Item 1.   When the second target torque calculation means passes the predetermined torque region from the upper side to the lower side while the first target torque is decreasing, the second target torque calculation means until the first target torque reaches a lower limit value of the predetermined torque region. The second target torque is held at the upper limit value of the predetermined torque region, and thereafter, the second target torque is decreased at a reduction rate larger than the first target torque until the second target torque matches the first target torque. The torque control apparatus for a vehicle according to claim 1 or 2, characterized by   The torque change speed setting means for setting the increase speed or the decrease speed of the second target torque to a smaller value as the speed ratio of the transmission is larger. The vehicle torque control apparatus described. A rotation speed detection means for detecting the rotation speed of the internal combustion engine;
The first target torque calculation means calculates the first target torque by proportional-integral control so that the detected rotation speed of the internal combustion engine converges to a predetermined target rotation speed,
5. The apparatus according to claim 1, further comprising a changing unit that changes an upper limit value that defines an upper limit of an integral term of the proportional-integral control in accordance with a gear ratio of the transmission. Vehicle torque control device. The predetermined torque region is an abnormal noise generation torque region in which abnormal noise is likely to occur,
The upper limit value and the lower limit value of the abnormal noise generation torque region include the amplitude of the transmission input torque that is input in the state of vibration to the transmission, the driving state in which the internal combustion engine drives the drive wheels, and the internal combustion engine 6. The vehicle torque control device according to claim 1, wherein the vehicle torque control device is set based on a relationship with a predetermined torque value representing a boundary with a driven state driven by the drive wheel. 7. . The transmission is a stepped transmission that sets a gear ratio by a plurality of gear stages,
The apparatus further comprises prohibiting means for prohibiting calculation of the second target torque by the second target torque calculating means when the vehicle is in an idling driving state while the vehicle is stopped or when the transmission is in a neutral state. The vehicle torque control device according to claim 6. The transmission is a stepped transmission that sets a gear ratio by a plurality of gear stages,
The apparatus further comprises prohibiting means for prohibiting the calculation of the second target torque by the second target torque calculating means when the gear stage of the transmission is set to a predetermined gear speed at which abnormal noise is unlikely to occur. The vehicle torque control device according to claim 6 or 7, wherein the vehicle torque control device is characterized.

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