JPH02241845A - Control device for vehicle driving system - Google Patents

Abstract

PURPOSE:To control the car speed to the target car speed by setting the target car speed based on the accelerator operation quantity, calculating the target drive torque based on the target car speed, and controlling the shift ratio of a continuously variable transmission and the output torque of an internal combustion engine. CONSTITUTION:A means M1 sets the target car speed based on the accelerator operation quantity, and a means M2 calculates the target drive torque based on the target car speed. A means M3 calculates the target input rotating speed of a continuously variable transmission based on the target drive torque and the actual car speed, and a means M4 feedback-controls the shift ratio so that the continuously variable transmission has the target input rotating speed. A means M5 calculates the target engine torque based on the shift ratio of the continuously variable transmission and the target drive torque, and a means M6 calculates the control quantity of the engine torque to the target engine torque based on the target engine torque and the rotating speed of an internal combustion engine. A means M7 controls the internal combustion engine in response to the control quantity.

Description

[Detailed description of the invention] [Field of industrial application] The present invention (Table 1) Control of a vehicle drive system equipped with a continuously variable transmission capable of steplessly adjusting the gear ratio in the power transmission system from an internal combustion engine to a drive shaft Regarding equipment, especially the gear ratio of continuously variable transmissions and internal combustion a
The present invention relates to a control device for a vehicle drive system that optimally controls the output torque of a leaper.

[Prior Art] Conventionally, as described in, for example, Japanese Unexamined Patent Publication No. 62-110536, a vehicle has been equipped with a continuously variable transmission capable of steplessly adjusting a gear ratio in a power transmission system from an internal combustion engine to a drive shaft. In this process, a target drive torque of the vehicle is set based on the amount of accelerator operation (accelerator opening degree) by the vehicle driver and the vehicle speed, and the target input rotation speed of the continuously variable transmission and the internal combustion engine are determined based on the set target drive torque. 2. Description of the Related Art A vehicle drive system control device is known that determines a throttle opening and controls a gear ratio of a continuously variable transmission and an output torque of an internal combustion engine.

This type of device (17) was developed with the aim of making it possible to drive a vehicle with the driving torque required by the vehicle driver and with optimal fuel efficiency, and as described above, it is By controlling the gear ratio of the continuously variable transmission and the output torque of the internal combustion engine based on this, it becomes possible to drive the vehicle optimally.

[Invention solves the problem 1. However, with the above device, one problem is that the vehicle drive torque, which is the control target, is set based on the accelerator opening and vehicle speed, so it is not possible to control the vehicle speed to the target vehicle speed requested by the vehicle driver. In other words, in the above device, 11. If the accelerator opening is the acceleration requested by the vehicle driver, 1. Since the target drive torque is set based on the accelerator opening degree and vehicle speed, although the vehicle can be accelerated or decelerated according to the accelerator operation performed by the vehicle driver, This system cannot be applied to a so-called target vehicle speed tracking system that controls the vehicle speed to a target vehicle speed, and the vehicle speed control has to be left to the vehicle driver's accelerator operation to adjust the acceleration/deceleration. The objective of this project is to enable vehicles equipped with a step-change transmission to not only drive the vehicle with optimal fuel efficiency as in the past, but also to control the vehicle speed to the target vehicle speed requested by the vehicle driver. [Means for Solving the Problem] That is, as illustrated in Table 1 of the configuration of the present invention made to achieve the above object, an internal combustion engine is used as a drive source, and a gear ratio can be adjusted steplessly in a power transmission system. In a control device for a vehicle drive system equipped with a continuously variable transmission, the accelerator is operated by the vehicle driver! A target vehicle speed setting means M1 that sets a target vehicle speed based on I-I, and a calculation formula preset in accordance with an equation of motion representing the behavior of a traveling vehicle based on the set target vehicle speed, determines the target drive of the vehicle. target drive torque calculation means M2 that calculates the torque; and target input rotation speed calculation means M3 that calculates the target input rotation speed of the continuously variable transmission based on the calculated target drive torque and the actual vehicle speed of the vehicle. and a gear ratio control means M that performs feedback control on the gear ratio of the continuously variable transmission so that the input rotational speed of the continuously variable transmission becomes the target input rotational speed.
4, target engine torque calculation means M5 for calculating a target engine torque of the internal combustion engine based on the gear ratio of the continuously variable transmission controlled by the gear ratio control means M4 and the target drive torque; control amount calculation means M6 for calculating a control amount of the internal combustion engine for controlling the engine torque to the target engine torque based on the determined target engine torque and the rotational speed of the internal combustion engine;

The gist of the present invention is a control device for a vehicle drive system, characterized in that it includes an engine torque control means M7 that controls an internal combustion engine according to the calculation result of the control amount calculation means M6.

Here, the calculation formula used by the target drive torque calculation means M2 to calculate the vehicle drive torque from the target vehicle speed set by the target vehicle speed setting means M1 can be set as follows, for example.

First, the equation of motion for a vehicle in a running state is as follows.If the vehicle weight is M, the vehicle speed is V, the drive torque uTD is the radius of the tire, and the running resistance is R, then it can be written as the following equation (1).

M-dV/dt=(TD/r)-R=(1) Above formula (1)
In , if the formula is modified by setting the vehicle speed to the target vehicle speed vO1 and the target drive torque for controlling the vehicle speed to the target vehicle speed vO as TDO, then the following formula for determining the target drive torque TDO required to control the vehicle speed to the target vehicle speed vO is obtained. (2) is obtained.

TDO= r ((M-d vo/ d t )+ R
) = (2) On the other hand, running resistance RjJ Assuming that the running resistance coefficient is Cn, the rolling resistance coefficient is Cr, and the front projected area of the vehicle is 80, it can be written as in the following equation (3).

R=Cn −A e −VO2+Cr −M
...(3) Therefore, from the target vehicle speed vO to the target drive torque T
To calculate DO, calculate running resistance R based on equation (3) above, then use equation (2) above to calculate target drive torque T.
All you have to do is calculate DO. Note that in order to calculate the target drive torque TDl using equation (2) above, a differential value of the target vehicle speed vO is required, so in actual control (Table 1) The latest target vehicle speed V 0 (k) and the previously determined target vehicle speed V 0 (k
-1), the calculation may be performed using an arithmetic expression such as the following equation (4) obtained by discretizing the above equation (2).

[Function] In the vehicle drive system control device of the present invention configured as described above, first, the target vehicle speed setting means M1 sets the target vehicle speed based on the accelerator operation amount by the vehicle driver, and Calculation means M2 calculates a target driving torque of the vehicle based on the set target vehicle speed. Then, the target input rotational speed calculation means M3 calculates the target input rotational speed of the continuously variable transmission based on the calculated target drive torque and the actual vehicle speed of the vehicle, and the gear ratio control means M4 calculates the target input rotational speed of the continuously variable transmission. The gear ratio of the continuously variable transmission is feedback-controlled so that the input rotational speed of the transmission becomes the calculated target input rotational speed.

On the other hand, the target drive torque calculated by the target drive torque calculation means M2 is calculated by the target engine torque calculation means M together with the gear ratio of the continuously variable transmission controlled by the gear ratio control means M4.
5 is converted into a target engine torque by the target engine torque calculation means M5. Then, the control amount calculation means M
6 calculates the control amount F of the internal combustion engine for controlling the engine torque to the target engine torque based on the target engine torque and the rotational speed of the internal combustion engine, and the engine torque control means M7 calculates the control amount F based on the calculated control amount. The output torque of the internal combustion engine is controlled accordingly.

That is, in the present invention, a target vehicle speed increase required by the vehicle driver is set based on the amount of accelerator operation by the vehicle driver, and a target drive torque required to drive the vehicle at the target vehicle speed is calculated from this target vehicle speed. The gear ratio of the gear transmission and the output torque of the internal combustion engine are controlled.

[Embodiments] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 2 is a schematic configuration diagram showing the overall configuration of a vehicle to which the present invention is applied.

As shown in the figure, the vehicle of this embodiment (Table 1) uses an internal combustion engine 2 as its power source, and the rotation of the internal combustion engine 2 is controlled by a clutch mechanism 4, a belt-type continuously variable transmission 1ll (hereinafter referred to as CVT) 6, a differential gear (not shown), etc. is transmitted to the drive shaft via.

First, connect the intake pipe 8 of the internal combustion engine 2 to the air cleaner 10. A throttle valve 12 that controls the flow of air (intake amount) flowing through the air cleaner 10. A surge tank 14 is provided to suppress pulsation of intake air. The throttle valve 12+,t is configured to be able to adjust its opening via a throttle actuator 16, and is provided with a throttle opening sensor 18 for detecting its opening (throttle opening) θT)l.

On the other hand, an input pulley 24 and an output pulley 26 provided on the CV T 61i human power shaft 20 and output shaft 22, respectively;
It is composed of a power transmission belt 28 wound around these manpower and output pulleys 24 and 26.

In addition, input/output booleys 24 and 26LL, respectively, input shaft 2
0 or the output shaft 22, and movable pulleys 34, 36 provided on the input shaft 20 or the output shaft 22 so as to be movable in the axial direction but not to rotate relative to the axis. By moving each of the movable pulleys 34 and 36 in the axial direction and changing the diameter (effective diameter) of the transmission belt 28, the gear ratio e of the CVT 6 can be adjusted.

That is, inside each movable pulley 34 and 36 (Table 3)
Pressure control valve 42
Hydraulic chambers whose volume changes are formed by hydraulic oil supplied via the flow control valve 44, and the CVT 6 is controlled by regulating the hydraulic pressure in each hydraulic chamber via the pressure control valve 42 and the flow control valve 44. The gear ratio e is controlled. Naoko 1-
A pressure control valve 42 and a flow control valve 44 for oil pressure control
Since the operation is well known, detailed explanation will be omitted.

Next, rotational speed sensors 46 to 50 are provided on the input/output shafts 20 and 22 of the CVT 6 and the output shaft of the internal combustion engine 2 to detect their rotational speeds, respectively. is input to the electronic control circuit 60.

Electronic control circuit 60 (table) Each of these rotational speed sensors 46 -
Detection signals from the throttle opening sensor 18 described above and the accelerator pedal 6 of the vehicle
Detection signals from the accelerator opening sensor 64 provided at
The purpose is to control the vehicle speed to the target vehicle speed requested by the vehicle driver with optimal fuel efficiency by controlling the drive of the CPU.
60 a, ROM 60 b, RAM 60
c. Kapo in and out! -60d, etc., and is configured as a well-known logic operation circuit.

Input/output capo]・1 table for 60d A drive circuit that drives the throttle actuator 16 according to the control voltage VTH of the throttle actuator 16 calculated in the control amount calculation process described later, and A drive circuit is provided for driving the pressure control valve 42 and the flow rate control valve 44 according to the control voltage VS of the CVT 6.
The output torque and gear ratio of the internal combustion engine 2 can be controlled through each of these drive circuits.

The control amount calculation process executed for controlling the vehicle drive system will be described below with reference to the flowchart of FIG. 3.

This control amount calculation process IA is a process that is executed every predetermined time (for example, 8m5ec-) after the internal combustion engine 2 is started. Various detection data obtained based on the signals, namely, input rotational speed NIN of CVT6, output rotational speed NOUT, rotational speed NE of internal combustion engine rWU2
, the throttle opening θ 虱 and the accelerator opening θ ACC representing the amount of depression of the accelerator pedal 62 are read, and the process proceeds to step 120 .

In step 120, based on the input rotational speed NIN and output rotational speed NOUT of the CVT 6 read above,
CVT6 gear ratio e (=N IN/N OUT)
Calculate. In the following step 130 (above), the output rotation speed N OUT of the CVT 6 read above and the RO
The vehicle speed V (=NOUT/γ) is calculated based on the reduction ratio data γ representing the reduction ratio of the power transmission system from the output shaft 22 of the CVT 6 to the drive wheels stored in the M60b, and the process proceeds to step 140. and in step 140 (top
Based on the accelerator opening degree θACC read above, the target vehicle speed VO('k
) is executed as the aforementioned target vehicle speed setting means M1.

Note that the subscript (k) added to the target vehicle speed vO is used to distinguish it from the target vehicle speed obtained during the previous process (k-1), which will be used in the process described later.V0(k) 1. represents the latest target vehicle speed obtained in this process.

When the target vehicle speed V 0 (k) is calculated in step 140 in this way, the process moves to step 150, and the calculated target vehicle speed V 0 (k) and the vehicle speed previously stored in the ROM 60b are Weight data M, running resistance coefficient data Cn, rolling resistance coefficient data Cr.

Based on the vehicle front projected area data Ae, the above (
3) Calculate the vehicle running resistance R using the formula.

In the following step 160, the calculated vehicle running resistance R and the latest target vehicle speed V obtained in step 140 are determined.
0(k) and the target vehicle speed V 0(k
-1), and the tire radius data r and vehicle weight data M stored in advance in the ROM 60b, target drive torque calculation that calculates the target drive torque TDO of the vehicle using the above-mentioned equation (4). The process as means M2 is executed, and the process moves to the following step 170.

In step 170, based on the target drive torque TDO obtained in step 60 and the vehicle speed V obtained in step 130, a preset calculation formula or map is used to determine the target input rotation of the CVT 6 to obtain the optimum fuel efficiency. Speed NlN0
The target input rotational speed calculating means M3 executes processing for calculating the target input rotational speed. Then, in the following step 180, a control voltage vS is applied to control the input rotation speed NIN of the CVT 6 to the target input rotation speed NIN0 based on the calculated target input rotation speed NlN0 and the input rotation speed NIN read in step 110. is calculated using the following equation (5).

VS= K1- (NlN0- NIN)
・(5) (Kl: proportionality constant) In this way, when the control voltage vS of the CVT 6 is calculated in step 80, the process moves to step 190, and the gear ratio of the CVT 6 calculated in step 120 is calculated. Based on e and the target drive torque TDO of the vehicle obtained in step 160, the target engine torque calculation means M5 calculates the target engine torque TEO using a preset arithmetic expression or map. In the following step 200, the calculated target engine torque TE
Based on O and the rotational speed NE of the internal combustion engine 2 read in step 110, the engine torque TEu target engine torque TEO is calculated using a preset calculation formula or map.
The control amount calculating means M6 calculates the target throttle opening θTHO for controlling the throttle opening θTHO.

Then, in the following step 210, based on (the calculated target throttle opening θT) 10 and the actual slot/small opening θTH read in step 110, the following formula (6
) is used to control the throttle actuator 16 control voltage V
After calculating TR, proceeding to the subsequent step 220 and setting the target vehicle speed VO(k) obtained in the above step 140 as V 0 (k-1) for the next process, the process is temporarily terminated. .

V TH:= K 2- (e THO-(3TH)
-(6) (However, 2: proportional constant) Furthermore, the control voltage vS and VTHI @ calculated in the above steps 180 and 210 are
It is used to control the gear ratio e of 6 and the throttle opening θTH.

In addition, in this embodiment, the process of step 180 for calculating the control voltage vS and the CVT 6
A drive pressure control valve 42 in the input/output capotro 0d that controls the gear ratio e. and the flow rate control valve 44 correspond to the above-mentioned speed ratio control means M4, and perform the process of step 210 to calculate the control voltage VTH, and the input/output capotro 0d to control the throttle opening θTH according to the calculation result. The drive circuit and the throttle actuator 16 correspond to the engine torque control means M7 described above.

As explained above, in this embodiment, the target vehicle speed vO is set according to the amount of depression of the accelerator pedal 62 operated by the vehicle driver (i.e., the accelerator opening degree), and the vehicle The target driving torque TDO required to control the vehicle speed vO to the target vehicle speed vO is calculated, and the gear ratio e of the CVT 6 and the output torque of the internal combustion engine 2 are controlled.

Therefore, according to this embodiment, it is possible to control the vehicle speed to a constant speed with optimal fuel efficiency according to the amount of depression of the accelerator pedal by the vehicle driver, and the vehicle driver does not have to press the accelerator pedal as in the past. The vehicle speed can be easily controlled to the target vehicle speed without adjusting the amount of depression.

Furthermore, in this embodiment, the target drive torque TDO of the vehicle for controlling the vehicle speed V to the target vehicle speed VO is determined by the equation of motion (
Since the calculation is based on equation (4) set in accordance with 1), the target drive torque is calculated based on the conventional system that sets the target drive torque from the accelerator opening and vehicle speed. There is no need to create a map etc. through experiments, which simplifies the design of the control system.

Here, in the above embodiment (t7), it was explained that predetermined values are used for the running resistance coefficient Cn and the rolling resistance coefficient Cr when calculating the running resistance R of the vehicle.
Since each of these coefficients actually changes depending on disturbances such as the wind direction, road surface condition, etc., these various disturbances may be detected and the above coefficients may be corrected.

[Effects of the Invention] As explained above, in the vehicle drive system control device of the present invention, a target vehicle speed requested by the vehicle driver is set from the amount of accelerator operation by the vehicle driver, and the vehicle is set to the target speed from this target vehicle speed. The target drive torque required to drive the vehicle at the same speed is calculated to control the gear ratio of the continuously variable transmission and the output torque of the internal combustion engine. Therefore, unlike conventional devices that directly set the vehicle's target drive torque based on the amount of accelerator operation by the vehicle driver and vehicle speed, the vehicle can not only be driven with optimal fuel efficiency, but also 1. Set the vehicle speed to a constant vehicle speed. : Possible to control. In other words, in order to drive the vehicle at a constant speed (Table 1), there is no need to adjust the vehicle's acceleration/deceleration by operating the accelerator as in the past; instead, the amount of accelerator operation can be set to a constant value according to the target vehicle speed, so the accelerator can be easily adjusted. The vehicle can be operated at a constant speed.Furthermore, in the present invention, the target driving torque of the vehicle for controlling the vehicle speed to the target vehicle speed is calculated using an arithmetic expression set according to the equation of motion of the vehicle. Therefore, there is no need to create a map or the like for calculating the target drive torque through experiments, unlike a device that sets the target drive torque from the accelerator opening and vehicle speed, and the design of the control system is simplified.

[Brief explanation of drawings]

FIG. 1 is a block diagram illustrating the configuration of the present invention, and FIG. 2 is a block diagram showing the overall configuration of the vehicle drive system according to the embodiment.
The figure is a flowchart showing a control amount calculation process for vehicle drive system control executed by an electronic control circuit. Ml...Target vehicle speed setting means M2...Target drive torque calculation means M3...Target input rotational speed calculation means M4...Gear ratio control means M5...Target engine I/lux calculation means M6... Controlled amount calculation means Ml... Engine torque control means 2... Internal combustion engine 6... CVT 16... Throttle actuator 18... Throttle opening sensor

Claims (1)

[Scope of Claims] A control device for a vehicle drive system that uses an internal combustion engine as a drive source and is equipped with a continuously variable transmission in the power transmission system that can adjust the gear ratio steplessly, the control device comprising: an internal combustion engine as a drive source; A target vehicle speed setting means for setting a target vehicle speed, and a preset arithmetic expression based on the set target vehicle speed in accordance with an equation of motion representing the behavior of the traveling vehicle,
Target drive torque calculation means for calculating a target drive torque of the vehicle; Target input rotation speed calculation for calculating a target input rotation speed of the continuously variable transmission based on the calculated target drive torque and the actual vehicle speed of the vehicle. means, a gear ratio control means for feedback controlling the gear ratio of the continuously variable transmission so that the input rotational speed of the continuously variable transmission becomes the target input rotational speed, and the gear ratio control means controlled by the gear ratio control means. Target engine torque calculation means for calculating a target engine torque of the internal combustion engine based on the gear ratio of the continuously variable transmission and the target drive torque, and based on the calculated target engine torque and the rotational speed of the internal combustion engine, A control amount calculation means for calculating a control amount of the internal combustion engine for controlling the engine torque to a target engine torque, and an engine torque control means for controlling the internal combustion engine according to the calculation result of the control amount calculation means. A control device for a vehicle drive system characterized by the following.