JP2010151107A - Control unit for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control unit for a vehicle capable of reducing man-hours since special adaptation work is unnecessary due to no use of a map at the calculation of target pump torque from target turbine torque and improving development efficiency. <P>SOLUTION: In the control unit for a vehicle having an internal combustion engine 1 and a torque converter 2 for transmitting power via a liquid, the control unit for a vehicle comprises: a target turbine torque calculation means (S3) for calculating the target turbine torque of the torque converter 2 in response to operating conditions; a target torque capacity calculation means (S8) for calculating target torque capacity of the torque converter 2 on the basis of the target turbine torque; an actual torque capacity calculation means (S9) for calculating actual torque capacity of the torque converter 2; a target pump acceleration torque calculation means (S13) for calculating target pump acceleration torque according to difference torque capacity as a difference between the target torque capacity and the actual torque capacity; a target pump torque calculation means (S14) for calculating the target pump torque by adding the target torque capacity and the target pump acceleration torque; and an output torque control means for controlling output torque of the internal combustion engine 1 to the target pump torque. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle control apparatus.

As a conventional vehicle control device, there is one that calculates a target engine rotational speed from a target turbine torque of a torque converter and a rotational speed of a turbine runner with reference to a map (for example, see Patent Document 1).
JP 2002-225590 A

  However, the above-described conventional vehicle control device has a problem that development work is poor because work for adapting the map is required.

  The present invention has been made paying attention to such conventional problems, and aims to improve development efficiency.

  The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected, it is not limited to this.

  The present invention is a vehicle control device including an internal combustion engine (1) and a torque converter (2) that transmits power via a fluid, and a target turbine torque of the torque converter (2) according to an operating state. Target turbine torque calculating means (S3) for calculating the target torque capacity calculating means (S8, 101) for calculating the target torque capacity of the torque converter (2) based on the target turbine torque, and the torque converter (2) Actual torque capacity calculating means (S9, 102) for calculating the actual torque capacity, and target pump acceleration torque calculating means for calculating the target pump acceleration torque according to the differential torque capacity that is the difference between the target torque capacity and the actual torque capacity. (S13, 104), the target torque capacity and the target pump acceleration torque are added to calculate the target pump torque of the torque converter (2). That the target pump torque calculating means (S14,105), and an output torque control means for controlling the output torque of the internal combustion engine (1) to the target pump torque (4), characterized in that it comprises a.

  According to the present invention, when the target pump torque is calculated from the target turbine torque, a map is not used, so that special adaptation work is unnecessary, man-hours can be reduced, and development efficiency can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a vehicle control apparatus according to an embodiment of the present invention.

  The vehicle control device includes an engine 1, a torque converter 2, a transmission mechanism 3, and a controller 4.

  The engine 1 generates power for rotating the drive wheels 5.

  The torque converter 2 includes a pump impeller 21 and a turbine runner 22. The pump impeller 21 and the turbine runner 22 are housed in a hermetically sealed housing. The pump impeller 21 applies force to the internal oil by the rotation of the engine 1. The turbine runner 22 transmits the power of the engine 1 received through the oil to the transmission mechanism 3.

  The speed change mechanism 3 outputs the motive power of the engine 1 input via the torque converter 2 by increasing / decreasing the speed according to the speed selected according to the driving state.

  The controller 4 includes a microcomputer having a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), and an input / output interface (I / O interface). The controller 4 receives signals from various sensors such as an accelerator stroke sensor 41 that detects the amount of depression of the accelerator pedal and a crank angle sensor signal 42 that detects the engine rotation speed. The mechanism 3 is controlled.

  In general, the characteristics of the torque converter 2 are expressed using a torque ratio t and a torque capacity coefficient τ, both of which are known as a function of the speed ratio e. The speed ratio e represents the state of oil flow inside the torque converter. The angular speed of the turbine runner (hereinafter referred to as “turbine angular speed”) as the output shaft is the angular speed of the pump impeller (hereinafter referred to as “pump angular speed”) as the input shaft. The value divided by.

  FIG. 2 is a diagram showing the relationship between the speed ratio e and the torque capacity coefficient τ.

  The torque capacity coefficient τ represents how much torque is required to turn the pump impeller 21, and is a value obtained by dividing the pump torque (input shaft torque) by the square of the pump angular velocity. As shown in FIG. 2, the torque capacity coefficient τ rapidly decreases when the speed ratio e of the torque converter 2 exceeds 0.8, and becomes 0 when the speed ratio e is 1.

  FIG. 3 is a diagram showing the relationship between the speed ratio e and the torque ratio t.

  The torque ratio t represents the performance of the torque converter 2 and refers to a value obtained by dividing the pump torque by the turbine torque (output shaft torque). As shown in FIG. 3, the torque ratio t becomes larger than 1 in a region below the coupling point where the torque converter 2 has a torque increasing action.

  Here, the conventional torque converter 2 has a feeling of slip such that when the accelerator pedal is depressed, the acceleration of the vehicle starts after the engine speed increases. As a result, there is a problem that there is a delay from when the accelerator pedal is depressed until the vehicle accelerates. In addition, when the accelerator pedal is depressed, the vehicle suddenly accelerates, and there is a problem that it is difficult to operate the pedal to obtain the intended acceleration feeling.

  These problems are that the torque capacity coefficient τ suddenly decreases when the speed ratio e of the torque converter 2 exceeds 0.8, and the torque capacity coefficient τ becomes 0 when the speed ratio e becomes 1. Because of that. In the region where the speed ratio e where the torque capacity coefficient τ suddenly decreases is 0.8 to 1, even if torque is applied to the pump impeller 21, only the pump angular velocity changes and the turbine torque becomes substantially zero. However, if torque is applied as it is, the pump angular velocity increases, the speed ratio e decreases, the torque capacity coefficient τ suddenly increases, and the turbine torque rises rapidly. Because of this characteristic, it shows a delay and sudden response to pedal operation.

  Therefore, in the present embodiment, the slip feeling of the torque converter 2 is suppressed by calculating the target pump torque from the target turbine torque of the torque converter 2.

  It is well known that the turbine torque of the torque converter 2 can be calculated by multiplying the torque capacity coefficient τ by the square of the pump angular velocity and the torque ratio t. However, the method for calculating the pump torque necessary for obtaining a desired turbine torque is only known using a map except when traveling in an equilibrium state (constant speed). When calculating using a map, map adaptation work is required, and development efficiency decreases. Therefore, in the present embodiment, the target pump torque is calculated from the target turbine torque of the torque converter 2 using a mathematical formula.

  FIG. 4 is a flowchart for explaining a means for calculating the target pump torque from the target turbine torque of the torque converter 2. The controller 4 executes this routine at a predetermined calculation cycle (for example, 10 ms) while the engine 1 is operating.

  In step S1, the controller 4 calculates a target acceleration based on the accelerator pedal depression amount and the vehicle speed.

  In step S2, the controller 4 calculates a target driving force for setting the vehicle to a target acceleration.

In step S3, the controller 4 calculates the target turbine torque TQ _turbine _ _tg by dividing the target driving force at the current gear ratio.

In step S4, the controller 4 reads the pump angular velocity ω _pump and the turbine angular velocity ω _turbin . The pump angular velocity ω _pump is calculated based on the crank angle sensor signal. The turbine angular velocity is calculated based on the angular velocity of the drive wheels 5 and the reduction ratio of the speed change mechanism 3.

In step S5, the controller 4 calculates the speed ratio e by the following equation (1) based on the pump angular velocity ω _pump and the turbine angular velocity ω _turbin .

In step S6, the controller 4 calculates the torque capacity coefficient τ from the speed ratio e with reference to the table shown in FIG. The torque capacity coefficient τ is the torque capacity TQ _capacity
And the following formula (2) based on the pump angular velocity ω _pump .

In step S7, the controller 4 calculates the torque ratio t from the speed ratio e with reference to the table of FIG. 3 described above. The torque ratio t is defined by the following equation (3) based on the turbine torque TQ _turbine and the pump torque TQ _pump .

In step S8, the controller 4, based on the target turbine torque TQ _turbine _ _tg and the torque capacity coefficient tau, to calculate a target torque capacity TQ _capacity _ _tg by the following equation (4).

In step S9, the controller 4 on the basis of the definition formula of the torque capacity coefficient tau ((2) see equation) to calculate the actual torque capacity TQ _capacity _ _now by the following equation (5).

In step S10, the controller 4, based on the target torque capacity TQ _capacity _ _tg and the actual torque capacity TQ _capacity _ _now, and calculates the difference torque capacity TQ _difference by the following equation (6).

In step S11, the controller 4 calculates the target pump angular velocity ω _{pump — tg} by the following equation (7).

Here, the torque capacity coefficient τ becomes substantially zero at the speed ratio e = 1. Therefore, depending on the speed ratio e, the solution of D diverges to plus or minus infinity. As a result, the target pump angular velocity ω _{pump — tg} increases, the target pump torque causes overshoot or undershoot, and the drivability deteriorates. Therefore, in this embodiment, upper and lower limits are set for D as in the following equation (8), and the divergence of the solution of D is suppressed to suppress the deterioration of drivability.

In step S12, the controller 4, based on the target pump angular velocity omega _pump _ _tg and pump angular velocity omega _pump, calculates a target pump angular acceleration alpha _pump _ _tg by the following equation (9).

In step S13, the controller 4 calculates the target pump angular acceleration torque TQ _acceleration by the following equation (10) based on the target pump angular acceleration α _{pump — tg} and the inertia moment I _pump around the pump shaft.

In step S14, the controller 4 calculates the target torque capacity TQ _capacity _ _tg, the target pump angle acceleration torque TQ _{acceleration,} based on the calculation of the target pump torque TQ _pump _ _tg by the following equation (11). Then, the controller 4 controls the fuel injection amount and the like so that the engine torque becomes the target pump torque TQ _{pump — tg} .

Figure 5 is a simplified block diagram illustrating the means for calculating the target pump torque TQ _pump _ _tg from the target turbine torque TQ _turbine _ _tg of the torque converter 2.

The target torque capacity calculating unit 100, the target turbine torque TQ _turbine _ _tg, a torque ratio t, are inputted. Target torque capacity calculation section 100, by dividing the target turbine torque TQ _turbine _ _tg in torque ratio t, calculates the target torque capacity TQ _capacity _ _tg.

The actual torque capacity calculation unit 101 receives a torque capacity coefficient τ and a pump angular velocity ω _pump . The actual torque capacity calculation unit 101 calculates the actual torque capacity TQ _{capacity — now} by multiplying the torque capacity coefficient τ by the square of the pump angular velocity ω _pump .

The difference torque capacity calculation section 102, and the target torque capacity TQ _capacity _ _tg, the actual torque capacity TQ _capacity _ _now, is input. Differential torque capacity calculating unit 102 calculates the difference torque capacity TQ _difference from the target torque capacity TQ _capacity _ _tg by subtracting the actual torque capacity TQ _capacity _ _now.

The target pump angle acceleration torque calculation section 103, and differential torque capacity TQ _difference, and the torque ratio t, and torque capacity coefficient tau, a pump angular velocity omega _pump, a moment of inertia I _pump around the pump shaft, is input. The target pump angular acceleration torque calculation unit 103 calculates a target pump angular acceleration torque TQ _acceleration based on these input values.

The target pump torque calculation unit 104, and the target torque capacity TQ _capacity _ _tg, the target pump angle acceleration torque TQ _{acceleration,} are input. Target pump torque calculation unit 104, and the target torque capacity TQ _capacity _ _tg, by adding the target pump angle acceleration torque TQ _{acceleration,} and calculates the target pump torque TQ _pump _ _tg.

  FIG. 6 is a diagram for explaining the effect of this embodiment.

  As shown in FIG. 6, according to the present embodiment, when the accelerator pedal is depressed at time t1 (FIG. 6A), the turbine torque follows without delay with respect to the change in pump torque (FIG. 6). (B)). Thereby, when the accelerator pedal is depressed, the vehicle accelerates quickly (FIGS. 6E and 6F), so that it is possible to suppress the driver from feeling slipping or sudden acceleration.

  According to the present embodiment described above, the target torque capacity is obtained from the target turbine torque, and the differential torque capacity that is the difference from the actual torque capacity is calculated. Then, the target engine rotational speed (target pump angular speed) is obtained according to the differential torque capacity, the target pump angular acceleration torque is calculated from this value, and the target torque capacity is added to this to calculate the target pump torque.

  Thus, by calculating the target pump torque from the target turbine torque, a delay from when the accelerator pedal is operated to when the vehicle is accelerated can be reduced and accelerated. As a result, it is possible to suppress the driver from feeling slippery or sudden acceleration.

  Further, when calculating the target pump torque from the target turbine torque, the torque ratio t and the torque capacity coefficient τ are used, and no map is used, so that no special adaptation work is required and man-hours can be reduced.

  Further, since the program size can be reduced by not using the map, the occupation ratio of the CPU and the memory of the controller 4 can be suppressed. As a result, resources can be redistributed to other functions and a cheaper CPU can be used.

  Note that the present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

It is a schematic block diagram of the control apparatus of the internal combustion engine by this embodiment. It is the figure which showed the relationship between a speed ratio and a torque capacity coefficient. It is the figure which showed the relationship between speed ratio and torque ratio. It is a flowchart explaining the means to calculate a target pump torque from a target turbine torque. It is a simple block diagram explaining the means to calculate a target pump torque from a target turbine torque. It is a figure explaining the effect by this embodiment.

Explanation of symbols

1 engine (internal combustion engine)
2 Torque converter 4 Controller (output torque control means)
21 pump impeller 22 turbine runner S3 target turbine torque calculation means S4 pump angular speed calculation means S4 turbine angular speed calculation means S5 speed ratio calculation means S6 torque capacity coefficient calculation means S7 torque ratio calculation means S8 target torque capacity calculation means S9 actual torque capacity calculation means S11 Target pump angular velocity calculating means S12 Target pump angular acceleration calculating means S13 Target pump acceleration torque calculating means

Claims (5)

A vehicle control device comprising an internal combustion engine and a torque converter that transmits power via a fluid,
Target turbine torque calculating means for calculating a target turbine torque of the torque converter according to an operating state;
Target torque capacity calculating means for calculating a target torque capacity of the torque converter based on the target turbine torque;
An actual torque capacity calculating means for calculating an actual torque capacity of the torque converter;
Target pump acceleration torque calculating means for calculating a target pump acceleration torque according to a differential torque capacity that is a difference between the target torque capacity and the actual torque capacity;
Target pump torque calculating means for calculating the target pump torque of the torque converter by adding the target torque capacity and the target pump acceleration torque;
Output torque control means for controlling the output torque of the internal combustion engine to the target pump torque;
A vehicle control apparatus comprising: Pump angular velocity calculating means for calculating the angular velocity of the pump impeller of the torque converter;
Turbine angular velocity calculating means for calculating the angular velocity of the turbine runner of the torque converter;
Speed ratio calculating means for calculating a speed ratio of the torque converter based on an angular speed of the pump impeller and an angular speed of the turbine runner;
Torque ratio calculating means for calculating a torque ratio of the torque converter based on the speed ratio;
Torque capacity coefficient calculating means for calculating a torque capacity coefficient of the torque converter based on the speed ratio;
With
The target pump acceleration torque calculating means includes
Target pump angular velocity calculating means for calculating a target pump angular velocity based on the differential torque capacity, the pump angular velocity, the torque ratio, and the torque capacity coefficient;
Target pump angular acceleration calculating means for calculating a target pump angular acceleration based on the target pump angular velocity and the pump angular velocity,
The vehicle control device according to claim 1, wherein the target pump acceleration torque is calculated based on the target pump angular acceleration and an inertia moment around the pump impeller. 3. The vehicle control device according to claim 2, wherein the target pump angular velocity calculating means sets a predetermined upper limit value and lower limit value for the target pump angular velocity. The target torque capacity calculating means includes
The vehicle control device according to claim 2, wherein a target torque capacity is calculated based on the target turbine torque and the torque ratio. The actual torque capacity calculating means includes
The vehicle control device according to claim 2, wherein an actual torque capacity coefficient is calculated based on the pump angular velocity and the torque capacity coefficient.

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