Transmission control device

Abstract

To appropriately control a transmission by using target drive power in auto-cruise control.SOLUTION: A drive power demand → non drive power command converter 26 convers a target engine torque of a drive power demand calculated based on target drive power of a vehicle, which is output in auto-cruise control, into a throttle opening applied to an engine of a non-drive power demand, the engine having the same displacement as an engine driven by the drive force demand and configured to determine the throttle opening based on an accelerator opening. Then, by using the obtained throttle opening, the converter controls gear change of a transmission.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a transmission control device for a vehicle that performs engine control by auto-cruise. [Background technology]

[0002] Patent Document 1 shows that the target engine torque is determined by arbitrating between a drive demand type, in which the target engine torque is calculated from the accelerator opening and the engine is controlled according to the calculated target engine torque, and a non-drive demand type (also called a throttle demand type), in which the throttle opening is determined from the accelerator opening. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2006-298317 A Summary of the Invention [Problem to be solved by the invention]

[0004] Here, during auto-cruise, a drive demand type target engine torque is output in the auto-cruise control, and the engine drive is controlled by this, but since the transmission is controlled according to the throttle opening determined by the non-drive demand type, there are cases where consistency cannot be achieved. [Means for solving the problem]

[0005] The present invention is a transmission control device that controls the transmission during auto-cruise control, which automatically controls the driving force of a vehicle. The target engine torque of a driving force demand type, which is calculated based on the target driving force of the vehicle and output during auto-cruise control, is converted into a throttle opening when applied to a non-driving force demand type engine of the same displacement as an engine driven by the driving force demand type and in which the throttle opening is determined based on the accelerator opening, and the obtained throttle opening is used to control gear shifting of the transmission.

[0006] The transmission may be a continuously variable transmission such as a continuously variable transmission (CVT). Effect of the Invention

[0007] According to the present invention, in the control of the CVT by non-drive demand type control, appropriate gear change control can be performed by utilizing the command value from the auto-cruise control, which is drive demand type control. [Brief description of the drawings]

[0008] [Figure 1] 1 is a block diagram showing a schematic configuration for driving control in a vehicle; [Diagram 2] 4 is a block diagram showing a functional configuration of a control unit; FIG. [Diagram 3] FIG. 4 is a characteristic diagram showing engine torque characteristics of a non-driving demand type. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiment described herein.

[0010] "Overall Configuration" Fig. 1 is a block diagram showing a schematic configuration for driving control in a vehicle. The vehicle is equipped with an engine 10 as its drive source and a continuously variable transmission (hereinafter referred to as CVT) 12, and the output of the engine 10 is transmitted to wheels via the CVT 12 to rotate the wheels and drive the vehicle. The engine 10 may be an internal combustion engine that outputs rotational force by burning fuel such as gasoline. The CVT 12 may be a belt-type CVT in which a pair of pulleys are connected by a belt and the gear ratio is changed by changing the radial position at which the pulleys engage with the belt.

[0011] The control unit 14 controls the operation of the engine 10 and the CVT 12 based on various information such as engine speed, accelerator opening, vehicle speed, vehicle distance, set speed, and the like.

[0012] In particular, the control unit 14 has an auto-cruise control function as a driving assistance function that automatically controls engine output according to a set speed. The auto-cruise control function includes a cruise control system (referred to as CCS) that maintains the vehicle speed at a set speed, a variable speed limiter (referred to as ASL), and speed control according to the vehicle distance.

[0013] "Configuring Control" 2 is a block diagram showing a functional configuration of the control unit 14. As described above, the control unit 14 includes a CCS / ASL control unit 20, an engine control unit 30, and a CVT control unit 40.

[0014] The CCS / ASL control unit 20 performs cruise control (CCS) and variable speed limiter (ASL) control (CCS / ASL control). A target acceleration is input to the CCS / ASL control unit 20. This target acceleration is calculated by a known method from information such as vehicle speed, vehicle distance, and set speed. The target acceleration is input to a target driving force calculation unit 22. The target driving force calculation unit 22 calculates a target driving force from the target acceleration by referring to the vehicle weight and the like. The target driving force is input to a target engine torque calculation unit 24, which calculates a target engine torque by referring to the engine speed and the like. This target engine torque is calculated from the target acceleration of the vehicle and the required amount of the target driving force, and is a driving demand type (driving demand) target engine torque. Hereinafter, the driving demand will be referred to as driving demand and the non-driving demand as non-driving demand, as appropriate.

[0015] The target engine torque of the drive demand type engine according to a command from the CCS / ASL control is input to a drive demand-to-non-drive demand conversion unit 26. The drive demand-to-non-drive demand conversion unit 26 converts the target engine torque of the drive demand type engine into a target throttle opening of the non-drive demand type engine.

[0016] Fig. 3 is a characteristic diagram showing the engine torque characteristics of a non-drive demand type. The vertical axis is engine torque [Nm], the horizontal axis is engine speed [rpm], and a characteristic curve according to the throttle opening is shown. Here, this characteristic diagram was set assuming a non-drive demand type engine (target engine torque is determined from throttle opening and engine speed) with the same displacement as the installed engine 10, and shows the relationship (engine torque characteristics) between the throttle opening, engine speed, and engine torque, as well as the set operating line (dotted line).

[0017] In the drive demand to non-drive demand conversion unit 26, the throttle opening is obtained from the drive demand type target engine torque and the engine speed determined from a predetermined speed change schedule (shift schedule) by utilizing the characteristics of the characteristic diagram. That is, the throttle opening is obtained by determining the engine torque, which can be arbitrarily determined based on the target driving force, and the allocation of the speed change ratio from the engine torque characteristics assuming a non-drive demand type engine. In other words, since the shift schedule is determined so as to trace the operating line shown by the dashed line in FIG. 3, the target engine torque and the throttle opening assuming a non-drive demand type engine are determined based on the operating line.

[0018] The obtained throttle opening is input to a CCS required opening calculation unit 28, which calculates and outputs the CCS required opening (throttle opening), which is the throttle opening used to calculate the primary rotation speed of the CVT 12, taking into account various vehicle conditions.

[0019] When the vehicle is being driven under normal driver operation, the engine control unit 30 determines the throttle opening degree from the driver's accelerator opening degree, and controls the operation of the engine 10.

[0020] The accelerator opening caused by the driver's accelerator operation (driver accelerator opening) is input to a target engine torque calculation unit 32. This target engine torque calculation unit 32 calculates a target engine torque from the accelerator opening and the engine speed at that time. In other words, instead of calculating a target acceleration and a target driving force, the target engine torque is calculated from the accelerator opening and engine speed at that time, so that the target engine torque is calculated so as to behave like a non-driving engine.

[0021] The output of the target engine torque calculation unit 32 is input to a matrix circuit (max) 34. The target engine torque from the target engine torque calculation unit 24 of the CCS / ASL control unit 20 is also supplied to this matrix circuit 34. The matrix circuit 34 selects the target engine torque from the target engine torque calculation unit 24 during CCS / ASL control such as auto-cruise, and selects the target engine torque from the target engine torque calculation unit 32 during driving control by the driver, not during auto-cruise control.

[0022] The target engine torque from the matrix circuit 34 is input to a drive demand type torque model 36, where it is corrected according to a torque model corresponding to the engine mounted on the vehicle for which the target engine torque is set, and input to a target throttle opening degree calculation unit 38. The target throttle opening degree calculation unit 38 calculates a target throttle opening degree corresponding to the target engine torque, which is the output of the torque model 36. Then, the throttle of the engine 10 is controlled according to the obtained target throttle opening degree.

[0023] According to this engine control unit 30, when the driver operates the engine, the target engine torque calculation unit 32 obtains a target engine torque equivalent to a non-drive demand type engine in which the driver's accelerator opening and the throttle opening have a one-to-one relationship, and control is performed based on this target engine torque.

[0024] The CVT control unit 40 controls the CVT 12 based on the driver's accelerator opening. The driver's accelerator opening is input to a drive-to-non-drive conversion unit 42. This drive-to-non-drive conversion unit 42 calculates a throttle opening for calculating the primary rotation speed of the CVT 12 from the driver's accelerator opening, taking into account the running characteristics of the vehicle, etc. For the CVT 12, this throttle opening is equivalent to the CCS required opening.

[0025] Here, the driver-to-non-driver conversion unit 42 determines the throttle opening assuming a one-to-one relationship between the accelerator opening and the throttle opening. Therefore, the relationship between the throttle opening, engine torque, and engine speed in the case of a non-driver engine satisfies the engine torque characteristics shown in FIG.

[0026] The throttle opening, which is the output of the driver-to-non-driver conversion unit 42, is supplied to a target primary rotation speed calculation unit 46 via a matrix circuit (max) 44. The matrix circuit 44 is also supplied with the CCS requested opening from the CCS requested opening calculation unit 28, and selects the CCS requested opening during CCS / ASL control, and selects the throttle opening from the driver-to-non-driver conversion unit 42 during driving operation.

[0027] The target primary rotation speed calculation unit 46 calculates a target primary rotation speed from the input throttle opening and outputs the calculated target primary rotation speed. Then, the CVT 12 is controlled using the target primary rotation speed.

[0028] In this manner, in this embodiment, during auto-cruise control (CCS / ASL control), a non-driving force demand type throttle opening for a non-driving force demand type engine is obtained from a driving force demand type target engine torque calculated according to the target acceleration and the corresponding target driving force. The obtained throttle opening is then used to calculate the primary rotation speed of the CVT 12 and control the shift. Therefore, even during auto-cruise control, engine control and CVT control can be performed using a target engine torque assuming a non-driving force demand type engine, and the operating point of the CVT 12 can be accurately determined. [Explanation of symbols]

[0029] 10: engine, 14: control unit, 20: CCS / ASL control unit, 22: target driving force calculation unit, 24: target engine torque calculation unit, 26: drive torque to non-drive torque conversion unit, 28: CCS required opening calculation unit, 30: engine control unit, 32: target engine torque calculation unit, 34: matrix circuit, 36: torque model, 38: target throttle opening calculation unit, 40: CVT control unit, 42: drive torque to non-drive torque conversion unit, 44: matrix circuit, 46: target primary rotation speed calculation unit.

Claims

[Claim 1] A transmission control device that controls a transmission during auto-cruise control that automatically controls a driving force of a vehicle, converting a target engine torque of a driving force demand type, which is calculated based on a target driving force of a vehicle and is output in an auto-cruise control, into a throttle opening when applied to an engine of a non-driving force demand type, which has the same displacement as an engine driven by the driving force demand type and in which a throttle opening is determined based on an accelerator opening, Using the obtained throttle opening, the gear shift of the transmission is controlled. Transmission control device.

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